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In 1977, French excavations at Aï Khanoum in north-east Afghanistan—a foundation of Antiochus I Sotēr and subsequently one of the major cities of the Greco-Bactrian kingdom—of a building dating to shortly before the destruction of the place in 145 b.c.e. uncovered inter alia the remains of a papyrus and a parchment document. The papyrus text, dated by Cavallo on the basis of its letterforms to the mid third century b.c.e., preserved a fragment of a philosophical dialogue seemingly to be associated with the Peripatetic school. The second document consisted of two separate portions of a piece of parchment roughly assigned on the basis of its letterforms to the second half of the third or the first half of the second century b.c.e.; as also in the case of the papyrus, the letters survived not on the parchment itself but impressed upon the hardened dirt that surrounded it. Only column II of the original editors’ ‘Texte 2a’ (the more substantial of the two parchment fragments) contains a significant amount of text, which appears in neither TrGF nor PCG. I present it here without regard to standard editorial niceties, which are rendered impossible by the desperate state of the original document, now almost certainly lost, and the nature of the original publication.
In this work, we have theoretically investigated a model for the poly(2-methoxy-5(2'- ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV) photodegradation based on structural models for MEH-PPV oligomers in vacuum and in solvent (chloroform). We investigated how the incorporation of oxygen and breaking of vinyl double bonds affect the absorption spectra. The theoretical results are in excellent agreement with the experimental data if we assume that the incorporation of carbonyl group is the main mechanism associated with the photodegradation processes.
Computational acceleration of performance metric-based materials discovery via high-throughput screening and machine learning methods is becoming widespread. Nevertheless, development and optimization of the opto-electronic properties that depend on dilute concentrations of point defects in new materials have not significantly benefited from these advances. Here, the authors present an informatics and simulation suite to computationally accelerate these processes. This will enable faster and more fundamental materials research, and reduce the cost and time associated with the materials development cycle. Analogous to the new avenues enabled by current first-principles-based property databases, this type of framework will open entire new research frontiers as it proliferates.
Determining infectious cross-transmission events in healthcare settings involves manual surveillance of case clusters by infection control personnel, followed by strain typing of clinical/environmental isolates suspected in said clusters. Recent advances in genomic sequencing and cloud computing now allow for the rapid molecular typing of infecting isolates.
To facilitate rapid recognition of transmission clusters, we aimed to assess infection control surveillance using whole-genome sequencing (WGS) of microbial pathogens to identify cross-transmission events for epidemiologic review.
Clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, and Klebsiella pneumoniae were obtained prospectively at an academic medical center, from September 1, 2016, to September 30, 2017. Isolate genomes were sequenced, followed by single-nucleotide variant analysis; a cloud-computing platform was used for whole-genome sequence analysis and cluster identification.
Most strains of the 4 studied pathogens were unrelated, and 34 potential transmission clusters were present. The characteristics of the potential clusters were complex and likely not identifiable by traditional surveillance alone. Notably, only 1 cluster had been suspected by routine manual surveillance.
Our work supports the assertion that integration of genomic and clinical epidemiologic data can augment infection control surveillance for both the identification of cross-transmission events and the inclusion of missed and exclusion of misidentified outbreaks (ie, false alarms). The integration of clinical data is essential to prioritize suspect clusters for investigation, and for existing infections, a timely review of both the clinical and WGS results can hold promise to reduce HAIs. A richer understanding of cross-transmission events within healthcare settings will require the expansion of current surveillance approaches.
Investigations into the existence of life in other parts of the cosmos find strong parallels with studies of the origin and evolution of life on our own planet. In this way, astrobiology and paleobiology are married by their common interest in disentangling the interconnections between life and the surrounding environment. In this way, a cross-point of both sciences is paleometry, which involves a myriad of imaging and geochemical techniques, usually non-destructive, applied to the investigation of the fossil record. In the last decades, paleometry has benefited from an unprecedented technological improvement, thus solving old questions and raising new ones. This advance has been paralleled by conceptual approaches and discoveries fuelled by technological evolution in astrobiological research. In this context, we present some new data and review recent advances on the employment of paleometry to investigations on paleobiology and astrobiology in Brazil in areas such biosignatures in Ediacaran microbial mats, biogenicity tests on enigmatic Ediacaran structures, research on Ediacaran metazoan biomineralization, fossil preservation in Cretaceous insects and fish, and finally the experimental study on the decay of fish to test the effect of distinct types of sediment on soft-tissue preservation, as well as the effects of early diagenesis on fish bone preservation.
The National Enforcement Investigations Center of the EPA provides support services for the enforcement activities of the Agency. Recently, we have analyzed hazardous wastes as part of efforts to enforce the Resource Conservation and Recovery Act and the Superfund Act. Sample preparation for inorganic elemental analysis is a difficult and time-consuming step. Thus, it would be desirable to be able to use x-ray fluorescence methods which require relatively little sample preparation for the analysis of solid hazardous wastes. A major problem to be overcome is the need to calibrate for a large variety of samples. However, a compensating factor is that the error will be largely determined by the sampling error and the measurement accuracy is not quite so critical.
The National Enforcement. Investigations Center of the EPA provides support services for the enforcement activities of the Agency. Recently, we have analyzed hazardous wastes as part of efforts to enforce the Resource Conservation and Recovery Act. Inorganic analysis often consists of elemental determinations. However, sometimes it is necessary to identify specific compounds. Some wastes are classified as hazardous by their origin, for instance, the wastes from the manufacture of several chromium pigments. On occasion, it is necessary to trace wastes to their source. In cleaning dumps and treating wastes, knowledge of the compounds present is useful.
This paper discusses the use of a personal computer in the x-ray diffraction laboratory. DARC (Digital Automated Hocking Curve) Topography is a system in which a PC is used extensively. Using this system as an example, the tsany uses and benefits of the PC as a tool will be explained.
Recently, a new class of carbon allotrope called protomene was proposed. This new structure is composed of sp2 and sp3 carbon-bonds. Topologically, protomene can be considered as an sp3 carbon structure (∼80% of this bond type) doped by sp2 carbons. First-principles simulations have shown that protomene presents an electronic bandgap of ∼3.4 eV. However, up to now, its mechanical properties have not been investigated. In this work, we have investigated protomene mechanical behavior under tensile strain through fully atomistic reactive molecular dynamics simulations using the ReaxFF force field, as available in the LAMMPS code. At room temperature, our results show that the protomene is very stable and the obtained ultimate strength and ultimate stress indicates an anisotropic behavior. The highest ultimate strength was obtained for the x-direction, with a value of ∼110 GPa. As for the ultimate strain, the highest one was for the z-direction (∼25% of strain) before protomene mechanical fracture.
LSJ s.v. A defines ἀληθινός as meaning ‘truthful, trusty’ of persons and ‘true, genuine’ of objects, and offers Amphis, fr. 26 (preserved at Ath. Deipn. 2.57b and 7.277c, and identified in the latter passage as drawn from a play entitled Leukas) as an example of the second sense:
ὅστις ἀγοράζων ὄψον <- x- ˘ ->
ἐξὸν ἀπολαύειν ἰχθύων ἀληθινῶν
ῥαφανῖδας ἐπιθυμεῖ πρίασθαι, μαίνεται
Anyone who, when shopping for dainties …
wants to purchase radishes, when he has a chance
to enjoy alêthinoi fish, is crazy.
The context of the fragment is unknown. But the speaker is patently drawing a contrast not between ‘real fish’ and something that resembles fish (‘false fish’), as LSJ would have it, but between a type of fish that any sensible person would buy for dinner, should the opportunity arise, and radishes, which are edible but unexciting fare. So too at Macho 28–32, when King Ptolemy's guests were served a variegated rockfish (πετραίου … ποικίλου), three κωβιοί cut into steaks, and καράβων … ἀληθινῶν (29)—literally ‘real crayfish’—they were astonished and delighted. The reaction suggests that the banqueters were happy because the crayfish Ptolemy served matched the quality of the other seafood he set before them, not because the king had declined to deceive them (sc. by serving a different food disguised as crayfish).
Breakthrough Listen is a 10-yr initiative to search for signatures of technologies created by extraterrestrial civilisations at radio and optical wavelengths. Here, we detail the digital data recording system deployed for Breakthrough Listen observations at the 64-m aperture CSIRO Parkes Telescope in New South Wales, Australia. The recording system currently implements two modes: a dual-polarisation, 1.125-GHz bandwidth mode for single-beam observations, and a 26-input, 308-MHz bandwidth mode for the 21-cm multibeam receiver. The system is also designed to support a 3-GHz single-beam mode for the forthcoming Parkes ultra-wideband feed. In this paper, we present details of the system architecture, provide an overview of hardware and software, and present initial performance results.
A robust biomedical informatics infrastructure is essential for academic health centers engaged in translational research. There are no templates for what such an infrastructure encompasses or how it is funded. An informatics workgroup within the Clinical and Translational Science Awards network conducted an analysis to identify the scope, governance, and funding of this infrastructure. After we identified the essential components of an informatics infrastructure, we surveyed informatics leaders at network institutions about the governance and sustainability of the different components. Results from 42 survey respondents showed significant variations in governance and sustainability; however, some trends also emerged. Core informatics components such as electronic data capture systems, electronic health records data repositories, and related tools had mixed models of funding including, fee-for-service, extramural grants, and institutional support. Several key components such as regulatory systems (e.g., electronic Institutional Review Board [IRB] systems, grants, and contracts), security systems, data warehouses, and clinical trials management systems were overwhelmingly supported as institutional infrastructure. The findings highlighted in this report are worth noting for academic health centers and funding agencies involved in planning current and future informatics infrastructure, which provides the foundation for a robust, data-driven clinical and translational research program.
BACKGROUND: IGTS is a rare phenomenon of paradoxical germ cell tumor (GCT) growth during or following treatment despite normalization of tumor markers. We sought to evaluate the frequency, clinical characteristics and outcome of IGTS in patients in 21 North-American and Australian institutions. METHODS: Patients with IGTS diagnosed from 2000-2017 were retrospectively evaluated. RESULTS: Out of 739 GCT diagnoses, IGTS was identified in 33 patients (4.5%). IGTS occurred in 9/191 (4.7%) mixed-malignant GCTs, 4/22 (18.2%) immature teratomas (ITs), 3/472 (0.6%) germinomas/germinomas with mature teratoma, and in 17 secreting non-biopsied tumours. Median age at GCT diagnosis was 10.9 years (range 1.8-19.4). Male gender (84%) and pineal location (88%) predominated. Of 27 patients with elevated markers, median serum AFP and Beta-HCG were 70 ng/mL (range 9.2-932) and 44 IU/L (range 4.2-493), respectively. IGTS occurred at a median time of 2 months (range 0.5-32) from diagnosis, during chemotherapy in 85%, radiation in 3%, and after treatment completion in 12%. Surgical resection was attempted in all, leading to gross total resection in 76%. Most patients (79%) resumed GCT chemotherapy/radiation after surgery. At a median follow-up of 5.3 years (range 0.3-12), all but 2 patients are alive (1 succumbed to progressive disease, 1 to malignant transformation of GCT). CONCLUSION: IGTS occurred in less than 5% of patients with GCT and most commonly after initiation of chemotherapy. IGTS was more common in patients with IT-only on biopsy than with mixed-malignant GCT. Surgical resection is a principal treatment modality. Survival outcomes for patients who developed IGTS are favourable.
Facing a bottleneck in the growth of aquaculture, and a gap in the supply and demand of the highly beneficial n-3 long-chain PUFA (LC-PUFA), sustainable alternatives to traditional marine-based feeds are required. Therefore, in the present trial, a novel oil obtained from a genetically engineered oilseed crop, Camelina sativa, that supplied over 25 % n-3 LC-PUFA was tested as a sole dietary-added lipid source in Atlantic salmon (Salmo salar) feed. Three groups of fish were fed three experimental diets for 12 weeks with the same basal composition and containing 20 % added oil supplied by either a blend of fish oil and rapeseed oil (1:3) (COM) reflecting current commercial formulations, wild-type Camelina oil (WCO) or the novel transgenic Camelina oil (TCO). There were no negative effects on the growth, survival rate or health of the fish. The whole fish and flesh n-3 LC-PUFA levels were highest in fish fed TCO, with levels more than 2-fold higher compared with those of fish fed the COM and WCO diets, respectively. Diet TCO had no negative impacts on the evaluated immune and physiological parameters of head kidney monocytes. The transcriptomic responses of liver and mid-intestine showed only mild effects on metabolism genes. Overall, the results clearly indicated that the oil from transgenic Camelina was highly efficient in supplying n-3 LC-PUFA providing levels double that obtained with a current commercial standard, and similar to those a decade ago before substantial dietary fishmeal and oil replacement.
Diamond stands out in its ability to host hundreds of color centers, the most studied of which may be the nitrogen-vacancy and NE8 centers. The NE8 center, in particular, can generate single photons at an energy of 1.56 eV, but synthesis efforts are low yield and lack precise control of the defect structure and resulting optical properties. Complementing a bottom-up synthesis effort, we develop a rapid-screening computational approach for screening potential color centers in nanodiamond, focusing here on the nickel–nitrogen complexes. Formation and optical absorption energies are characterized with respect to defect stoichiometry and structure.
Graphene-based membranes have been investigated as promising candidates for water filtration and gas separation applications. Experimental evidences have shown that graphene oxide can be impermeable to liquids, vapors and gases, while allowing a fast permeation of water molecules. This phenomenon has been attributed to the formation of a network of nano capillaries that allow nearly frictionless water flow while blocking other molecules by steric hindrance effects. It is supposed that water molecules are transported through the percolated two-dimensional channels formed between graphene-based sheets. Although these channels allow fast water permeation in such materials, the flow rates are strongly dependent on how the membranes are fabricated. Also, some fundamental issues regarding the nanoscale mechanisms of water permeation are still not fully understood and their interpretation remains controversial. In this work, we have investigated the dynamics of water permeation through pristine graphene and graphene oxide model membranes that have strong impact on water/alcohol separation. We have carried out fully atomistic classical molecular dynamics simulations of systems composed of multiple layered graphene-based sheets into contact with a pure water reservoir under controlled thermodynamics conditions (e. g., by varying temperature and pressure values). We have systematically analysed how the transport dynamics of the confined nanofluids depend on the interlayer distances and the role of the oxide functional groups. Our results show the water flux is much more effective for graphene than for graphene oxide membranes. These results can be attributed to the H-bonds formation between oxide functional groups and water, which traps the water molecules and precludes ultrafast water transport through the nanochannels.