On the inner Double-Resonance Raman scattering process in bilayer graphene

The dispersion of phonons and the electronic structure of graphene systems can be obtained experimentally from the double-resonance (DR) Raman features by varying the excitation laser energy. In a previous resonance Raman investigation of graphene, the electronic structure was analyzed in the framework of the Slonczewski-Weiss-McClure (SWM) model, considering the outer DR process. In this work we analyze the data considering the inner DR process, and obtain SWM parameters that are in better agreement with those obtained from other experimental techniques. This result possibly shows that there is still a fundamental open question concerning the double resonance process in graphene systems.Comment: 5 pages, 3 figure

MEK inhibition is a promising therapeutic strategy for MLL-rearranged infant acute lymphoblastic leukemia patients carrying RAS mutations

Acute lymphoblastic leukemia (ALL) in infants is an aggressive malignancy with a poor clinical outcome, and is characterized by translocations of the Mixed Lineage Leukemia (MLL) gene. Previously, we identified RAS mutations in 14-24% of infant ALL patients, and showed that the presence of a RAS mutation decreased the survival chances even further. We hypothesized that targeting the RAS signaling pathway could be a therapeutic strategy for RAS-mutant infant ALL patients. Here we show that the MEK inhibitors Trametinib, Selumetinib and MEK162 severely impair primary RAS-mutant MLL-rearranged infant ALL cells in vitro. While all RAS-mutant samples were sensitive to MEK inhibitors, we found both sensitive and resistant samples among RAS-wildtype cases. We confirmed enhanced RAS pathway signaling in RASmutant samples, but found no apparent downstream over-activation in the wildtype samples. However, we did confirm that MEK inhibitors reduced p-ERK levels, and induced apoptosis in the RAS-mutant MLL-rearranged ALL cells. Finally, we show that MEK inhibition synergistically enhances prednisolone sensitivity,

Population redistribution in optically trapped polar molecules

We investigate the rovibrational population redistribution of polar molecules in the electronic ground state induced by spontaneous emission and blackbody radiation. As a model system we use optically trapped LiCs molecules formed by photoassociation in an ultracold two-species gas. The population dynamics of vibrational and rotational states is modeled using an ab-initio electric dipole moment function and experimental potential energy curves. Comparison with the evolution of the v"=3 electronic ground state yields good qualitative agreement. The analysis provides important input to assess applications of ultracold LiCs molecules in quantum simulation and ultracold chemistry.Comment: 6 pages, 5 figures, EPJD Topical issue on Cold Quantum Matter - Achievements and Prospect

Innovations in air sampling to detect plant pathogens

Many innovations in the development and use of air sampling devices have occurred in plant pathology since the first description of the Hirst spore trap. These include improvements in capture efficiency at relatively high air-volume collection rates, methods to enhance the ease of sample processing with downstream diagnostic methods and even full automation of sampling, diagnosis and wireless reporting of results. Other innovations have been to mount air samplers on mobile platforms such as UAVs and ground vehicles to allow sampling at different altitudes and locations in a short space of time to identify potential sources and population structure. Geographical Information Systems and the application to a network of samplers can allow a greater prediction of airborne inoculum and dispersal dynamics. This field of technology is now developing quickly as novel diagnostic methods allow increasingly rapid and accurate quantifications of airborne species and genetic traits. Sampling and interpretation of results, particularly action-thresholds, is improved by understanding components of air dispersal and dilution processes and can add greater precision in the application of crop protection products as part of integrated pest and disease management decisions. The applications of air samplers are likely to increase, with much greater adoption by growers or industry support workers to aid in crop protection decisions. The same devices are likely to improve information available for detection of allergens causing hay fever and asthma or provide valuable metadata for regional plant disease dynamics

Identification of genes transcriptionally responsive to the loss of MLL fusions in MLL-rearranged acute lymphoblastic leukemia

MLL-rearranged acute lymphoblastic leukemia (ALL) in infants (<1 year) is characterized by high relapse rates and a dismal prognosis. To facilitate the discovery of novel therapeutic targets, we here searched for genes directly influenced by the repression of various MLL fusions. Methods For this, we performed gene expression profiling after siRNA-mediated repression of MLLAF4, MLL-ENL, and AF4-MLL in MLL -rearranged ALL cell line models. The obtained results were compared with various already established gene signatures including those consisting of known MLL-AF4 target genes, or those associated with primary MLL-rearranged infant ALL samples. Results Genes that were down-regulated in response to the repression of MLL-AF4 and MLL-ENL appeared characteristically expressed in primary MLL-rearranged infant ALL samples, and often represented known MLL-AF4 targets genes. Genes that were up-regulated in response to the repression of MLL-AF4 and MLL-ENL often represented genes typically silenced by promoter hypermethylation in MLL-rearranged infant ALL. Genes that were aff

Targeting FLT3 in primary MLL-gene-rearranged infant acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) in infants is characterized by rearrangements of the mixed lineage leukemia (MLL) gene, drug resistance, and a poor treatment outcome. Therefore, novel therapeutic strategies are needed to improve prognosis. Recently, we showed that FLT3 is highly expressed in MLL rearranged ALL (MLL). Here we demonstrate FLT3 expression in infants with MLL (n = 41) to be significantly higher compared to both infant (n = 8; P < .001) and noninfant patients with ALL (n = 23; P = .001) carrying germline MLL genes. Furthermore, leukemic cells from infants with MLL were significantly more sensitive to the Fms-like tyrosine kinase 3 (FLT3) inhibitor PKC412 (N-benzoyl staurosporine) than noninfant ALL cells, and at least as sensitive as internal tandem duplication-positive (ITD+) AML cells. Surprisingly, activation loop mutations only occurred in about 3% (1 of 36) of the cases and no FLT3/ITDs were observed. However, measuring FLT3 phosphorylation in infants with MLL expressing varying levels of wild-type FLT3 revealed that high-level FLT3 expression is associated with ligand-independent FLT3 activation. This suggests that infant MLL cells displaying activated FLT3 as a result of overexpression can be targeted by FLT3 inhibitors such as PKC412. However, at concentrations of PKC412 minimall

Milagrito: a TeV air-shower array

Milagrito, a large, covered water-Cherenkov detector, was the world's first air-shower-particle detector sensitive to cosmic gamma rays below 1 TeV. It served as a prototype for the Milagro detector and operated from February 1997 to May 1998. This paper gives a description of Milagrito, a summary of the operating experience, and early results that demonstrate the capabilities of this technique.Comment: 38 pages including 24 figure

Toward understanding covid-19 recovery: national institutes of health workshop on postacute covid-19

Over the past year, the SARS-CoV-2 pandemic has swept the globe, resulting in an enormous worldwide burden of infection and mortality. However, the additional toll resulting from long-term consequences of the pandemic has yet to be tallied. Heterogeneous disease manifestations and syndromes are now recognized among some persons after their initial recovery from SARS-CoV-2 infection, representing in the broadest sense a failure to return to a baseline state of health after acute SARS-CoV-2 infection. On 3 to 4 December 2020, the National Institute of Allergy and Infectious Diseases, in collaboration with other Institutes and Centers of the National Institutes of Health, convened a virtual workshop to summarize existing knowledge on postacute COVID-19 and to identify key knowledge gaps regarding this condition