The mineral weathering ability of 45 bacterial strains belonging to the genus
Collimonas and coming from various terrestrial environments was compared to that of 5 representatives from the closely ...related genera
Herbaspirillum and
Janthinobacterium. Using glucose as the sole carbon source in a microplate assay for quantifying the release of iron and protons from biotite, all
Collimonas strains proved to be very efficient weathering agents, in contrast to the
Herbaspirillum and
Janthinobacterium strains. The weathering phenotype was also evident during growth of collimonads on mannitol and trehalose, but not on gluconic acid. All
Collimonas strains were able to solubilize inorganic phosphorus and produce gluconic acid from glucose, suggesting that acidification is one of the main mechanisms used by these bacteria for mineral weathering. The production of siderophores may also be involved, but this trait, measured as the ability of collimonads to mobilize iron, was shared with
Herbaspirillum and
Janthinobacterium strains. These findings are discussed in an ecological context that recognizes collimonads as mycophagous (fungal-eating) and efficient mineral weathering bacteria and suggests that this ability has evolved as an adaptation to nutrient-poor conditions, possibly as part of a mutualistic relationship with mycorrhizal fungi.
A portable monoenergetic 24 keV neutron source based on the \(^{124}\)Sb-\(^9\)Be photoneutron reaction and an iron filter has been constructed and characterized. The coincidence of the neutron ...energy from SbBe and the low interaction cross-section with iron (mean free path up to 29 cm) makes pure iron specially suited to shield against gamma rays from \(^{124}\)Sb decays while letting through the neutrons. To increase the \(^{124}\)Sb activity and thus the neutron flux, a \(>\)1 GBq \(^{124}\)Sb source was produced by irradiating a natural Sb metal pellet with a high flux of thermal neutrons in a nuclear reactor. The design of the source shielding structure makes for easy transportation and deployment. A hydrogen gas proportional counter is used to characterize the neutrons emitted by the source and a NaI detector is used for gamma background characterization. At the exit opening of the neutron beam, the characterization determined the neutron flux in the energy range 20-25 keV to be 5.36\(\pm\)0.20 neutrons per cm\(^2\) per second and the total gamma flux to be 213\(\pm\)6 gammas per cm\(^2\) per second (numbers scaled to 1 GBq activity of the \(^{124}\)Sb source). A liquid scintillator detector is demonstrated to be sensitive to neutrons with incident kinetic energies from 8 to 17 keV, so it can be paired with the source as a backing detector for neutron scattering calibration experiments. This photoneutron source provides a good tool for in-situ low energy nuclear recoil calibration for dark matter experiments and coherent elastic neutrino-nucleus scattering experiments.
The Ionospheric Connection Explorer, or ICON, is a new NASA Explorer mission that will explore the boundary between Earth and space to understand the physical connection between our world and our ...space environment. This connection is made in the ionosphere, which has long been known to exhibit variability associated with the sun and solar wind. However, it has been recognized in the 21st century that equally significant changes in ionospheric conditions are apparently associated with energy and momentum propagating upward from our own atmosphere. ICON’s goal is to weigh the competing impacts of these two drivers as they influence our space environment. Here we describe the specific science objectives that address this goal, as well as the means by which they will be achieved. The instruments selected, the overall performance requirements of the science payload and the operational requirements are also described. ICON’s development began in 2013 and the mission is on track for launch in 2018. ICON is developed and managed by the Space Sciences Laboratory at the University of California, Berkeley, with key contributions from several partner institutions.
BACKGROUND:The omentum provides abundant lymphatic tissue with reliable vascular anatomy, representing an ideal donor for vascularized lymph node transfer without risk for donor site lymphedema. We ...describe a novel, robotically assisted approach for omental flap harvest.
METHODS:All patients undergoing robotically assisted omentum harvest for vascularized lymph node transfer from 2017 to 2019 were identified. Patient demographics, intraoperative variables, and postoperative outcomes were reviewed.
RESULTS:Five patients underwent robotically assisted omentum flap harvest for vascularized lymph node transfer. The average patient age and body mass index were 51.2 years and 29.80 kg/m, respectively. Indications for lymph node transfer were upper extremity lymphedema following mastectomy, radiation, and lymphadenectomy (60.0%); congenital unilateral lower extremity lymphedema (20.0%); and bilateral lower extremity/scrotal lymphedema following partial penectomy and bilateral inguinal/pelvic lymphadenectomy (20.0%). Four patients (80.0%) underwent standard robotic harvest, whereas 1 patient underwent single-port robotic harvest. The average number of port sites was 4.4. All patients underwent omentum flap transfer to 2 sites; in 2 cases, the flap was conjoined, and in 3 cases, the flap was segmented. The average overall operative time was 9:19. The average inpatient hospitalization was 5.2 days. Two patients experienced cellulitis, which is resolved with oral antibiotics. There were no major complications. All patients reported subjective improvement in swelling and softness of the affected extremity. The average follow-up was 8.8 months.
CONCLUSIONS:Robotically assisted omental harvest for vascularized lymph node transfer is a novel, safe, and viable minimally invasive approach offering improved intra-abdominal visibility and maneuverability for flap dissection.
In a 26-year soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon cycling to investigate the potential consequences for the climate system. We found that ...soil warming results in a four-phase pattern of soil organic matter decay and carbon dioxide fluxes to the atmosphere, with phases of substantial soil carbon loss alternating with phases of no detectable loss. Several factors combine to affect the timing, magnitude, and thermal acclimation of soil carbon loss. These include depletion of microbially accessible carbon pools, reductions in microbial biomass, a shift in microbial carbon use efficiency, and changes in microbial community composition. Our results support projections of a long-term, self-reinforcing carbon feedback from mid-latitude forests to the climate system as the world warms.
RATIONALE:An exaggerated or persistent inflammatory activation after myocardial infarction (MI) leads to maladaptive healing and subsequent remodeling of the left ventricle. Foxp3 CD4 regulatory T ...cells (Treg cells) contribute to inflammation resolution. Therefore, Treg cells might influence cardiac healing post-MI.
OBJECTIVE:Our aim was to study the functional role of Treg cells in wound healing post-MI in a mouse model of permanent left coronary artery ligation.
METHODS AND RESULTS:Using a model of genetic Treg-cell ablation (Foxp3 mice), we depleted the Treg-cell compartment before MI induction, resulting in aggravated cardiac inflammation and deteriorated clinical outcome. Mechanistically, Treg-cell depletion was associated with M1-like macrophage polarization, characterized by decreased expression of inflammation-resolving and healing-promoting factors. The phenotype of exacerbated cardiac inflammation and outcome in Treg-cell–ablated mice could be confirmed in a mouse model of anti-CD25 monoclonal antibody–mediated depletion. In contrast, therapeutic Treg-cell activation by superagonistic anti-CD28 monoclonal antibody administration 2 days after MI led to improved healing and survival. Compared with control animals, CD28-SA–treated mice showed increased collagen de novo expression within the scar, correlating with decreased rates of left ventricular ruptures. Therapeutic Treg-cell activation induced an M2-like macrophage differentiation within the healing myocardium, associated with myofibroblast activation and increased expression of monocyte/macrophage-derived proteins fostering wound healing.
CONCLUSIONS:Our data indicate that Treg cells beneficially influence wound healing after MI by modulating monocyte/macrophage differentiation. Moreover, therapeutic activation of Treg cells constitutes a novel approach to improve healing post-MI.
The accurate identification of a host organism is an important component in the taxonomic recognition of a new species of parasite. Correct identification, curatorial management, and safekeeping of ...the host specimen from which a parasite type specimen is collected is also desirable. We recommend that the host from which the type of a new parasite species is described should be designated as a symbiotype.
PDF
