21 research outputs found
Transformation of tobacco with the BA5 cement protein gene from Balanus amphitrite
Expressing barnacle cement proteins genes such as the BA5 gene in plants may enable individual study and analysis. This technique is effective since barnacle cement is difficult to work with as a whole in the lab setting. The BA5 gene extracted from Balanus amphitrite is transferred to tobacco leaf tissue using Agrobacterium tumefaciens
Fate of gravitational collapse in semiclassical gravity
While the outcome of gravitational collapse in classical general relativity
is unquestionably a black hole, up to now no full and complete semiclassical
description of black hole formation has been thoroughly investigated. Here we
revisit the standard scenario for this process. By analyzing how semiclassical
collapse proceeds we show that the very formation of a trapping horizon can be
seriously questioned for a large set of, possibly realistic, scenarios. We
emphasise that in principle the theoretical framework of semiclassical gravity
certainly allows the formation of trapping horizons. What we are questioning
here is the more subtle point of whether or not the standard black hole picture
is appropriate for describing the end point of realistic collapse. Indeed if
semiclassical physics were in some cases to prevent formation of the trapping
horizon, then this suggests the possibility of new collapsed objects which can
be much less problematic, making it unnecessary to confront the information
paradox or the run-away end point problem.Comment: revtex4, 14 pages, 2 figure
Phenotypes of Non-Attached Pseudomonas aeruginosa Aggregates Resemble Surface Attached Biofilm
For a chronic infection to be established, bacteria must be able to cope with hostile conditions such as low iron levels, oxidative stress, and clearance by the host defense, as well as antibiotic treatment. It is generally accepted that biofilm formation facilitates tolerance to these adverse conditions. However, microscopic investigations of samples isolated from sites of chronic infections seem to suggest that some bacteria do not need to be attached to surfaces in order to establish chronic infections. In this study we employed scanning electron microscopy, confocal laser scanning microscopy, RT-PCR as well as traditional culturing techniques to study the properties of Pseudomonas aeruginosa aggregates. We found that non-attached aggregates from stationary-phase cultures have comparable growth rates to surface attached biofilms. The growth rate estimations indicated that, independently of age, both aggregates and flow-cell biofilm had the same slow growth rate as a stationary phase shaking cultures. Internal structures of the aggregates matrix components and their capacity to survive otherwise lethal treatments with antibiotics (referred to as tolerance) and resistance to phagocytes were also found to be strikingly similar to flow-cell biofilms. Our data indicate that the tolerance of both biofilms and non-attached aggregates towards antibiotics is reversible by physical disruption. We provide evidence that the antibiotic tolerance is likely to be dependent on both the physiological states of the aggregates and particular matrix components. Bacterial surface-attachment and subsequent biofilm formation are considered hallmarks of the capacity of microbes to cause persistent infections. We have observed non-attached aggregates in the lungs of cystic fibrosis patients; otitis media; soft tissue fillers and non-healing wounds, and we propose that aggregated cells exhibit enhanced survival in the hostile host environment, compared with non-aggregated bacterial populations
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Strumigenys perplexa (Smith, 1876) (Formicidae, Myrmicinae) a new exotic ant to Europe with establishment in Guernsey, Channel Islands
Ants are continually introduced into regions outside of their natural biogeographic ranges via global trade. The genus Strumigenys Smith 1860 (Formicidae: Myrmicinae) are minute predators with a growing history of global introductions, although tropical introductions into temperate zones are rarely able to establish outside of heated infrastructures. We report the first record of the Australasian Strumigenys perplexa (Smith 1876) to Europe and the British Isles from four sites on Guernsey, Channel Islands. This novel discovery is likely attributable to the species wide climatic and habitat tolerances, enabling the species to establish away from its natural range in Australasia and from heated-infrastructure. A key to the West Palaearctic Strumigenys species is provided alongside a preliminary and critical checklist of ant species recorded from the Channel Island archipelago, listing 32 species
NREL. Airborne Wind Energy
Airborne wind energy (AWE) is “the conversion of wind energy into electricity using tethered flying devices” (Schmehl 2020.) Pursuit of AWE and airborne wind energy systems began in 1980 (Loyd 1980). Interest and investment in AWE have grown substantially in the last decade, with approximately 70 active research entities including over 20 technology developers globally. This report describes technical analyses of various aspects of AWE and insight gained from dedicated outreach1 provided to the U.S. Department of Energy’s Wind Energy Technologies Office to underpin its response to the congressional request in the Energy Act of 2020 for a report on the “potential for, and technical viability of, airborne wind energy systems to provide a significant source of energy in the United States.
Recommended from our members
Cultivating intellectual community in academia: reflections from the Science and Technology Studies Food and Agriculture Network (STSFAN).
Scholarship flourishes in inclusive environments where open deliberations and generative feedback expand both individual and collective thinking. Many researchers, however, have limited access to such settings, and most conventional academic conferences fall short of promises to provide them. We have written this Field Report to share our methods for cultivating a vibrant intellectual community within the Science and Technology Studies Food and Agriculture Network (STSFAN). This is paired with insights from 21 network members on aspects that have allowed STSFAN to thrive, even amid a global pandemic. Our hope is that these insights will encourage others to cultivate their own intellectual communities, where they too can receive the support they need to deepen their scholarship and strengthen their intellectual relationships