2,053 research outputs found
EFFECT OF RECREATIONAL TRAIL TRAFFIC LEVEL ON EASTERN RED-BACKED SALAMANDER (PLETHODON CINEREUS) RELATIVE ABUNDANCE
The effects of roads and trails on terrestrial salamanders, primarily plethodontids, can be important. The abundance of terrestrial salamanders often increases with distance from roads. Less is known about the effects of recreational or hiking trails on terrestrial salamanders than is known about the effects of roads. We explored how low and high traffic trails in a suburban biological reserve affect the relative abundance of Eastern Red-backed Salamanders (Plethodon cinereus). We found more salamanders under cover objects next to low traffic trails compared to either high traffic trails or wooded areas without trails. At wooded sites, we found only striped morphs whereas at high traffic sites we found only unstriped morphs. Low traffic sites included a range of color morph frequencies. The proportion of females found in each site did not differ, nor did the mean size of the salamanders. Our results suggest that the impact of recreational walking trails needs to be examined more closely to see how and why the distributions of P. cinereus, and potentially other woodland salamanders, are affected and what trail characteristics are important in driving the apparent effects. Such information will contribute to the design and maintenance of walking trails in natural areas that minimize effects on terrestrial salamanders, and likely other organisms
Electron-phonon coupling in 122 Fe pnictides analyzed by femtosecond time-resolved photoemission
Based on results from femtosecond time-resolved photoemission, we compare
three different methods for determination of the electron-phonon coupling
constant {\lambda} in Eu and Ba-based 122 FeAs compounds. We find good
agreement between all three methods, which reveal a small {\lambda} < 0.2. This
makes simple electron-phonon mediated superconductivity unlikely in these
compounds.Comment: 11 pages, 3 figure
Ultrafast dynamics of occupied quantum well states in Pb/Si(111)
We investigate the ultrafast electron dynamics of occupied quantum well states (QWSs) in Pb/Si(111) with time-resolved photoemission spectroscopy. We find an ultrafast increase in binding energy of the QWSs driven by the optical excitation, while the electronic system is in a non-equilibrium state. We explain this transient energetic stabilization in the photoexcited state by an ultrafast modification of the Fermi level pinning, triggered by charge transfer across the Pb/Si interface. In addition, we observe the excitation of a coherent surface phonon mode at a frequency of ~2 THz, which modulates the QWS binding energy
Momentum dependent ultrafast electron dynamics in antiferromagnetic EuFe2As2
Employing the momentum-sensitivity of time- and angle-resolved photoemission
spectroscopy we demonstrate the analysis of ultrafast single- and many-particle
dynamics in antiferromagnetic EuFe2As2. Their separation is based on a
temperature-dependent difference of photo-excited hole and electron relaxation
times probing the single particle band and the spin density wave gap,
respectively. Reformation of the magnetic order occurs at 800 fs, which is four
times slower compared to electron-phonon equilibration due to a smaller
spin-dependent relaxation phase space
Targeting CXCR4 in AML and ALL
The interaction of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) blasts with the bone marrow microenvironment regulates self-renewal, growth signaling, as well as chemotherapy resistance. The chemokine receptor, CXC receptor 4 (CXCR4), with its ligand chemokine ligand 12 (CXCL12), plays a key role in the survival and migration of normal and malignant stem cells to the bone marrow. High expression of CXCR4 on AML and ALL blasts has been shown to be a predictor of poor prognosis for these diseases. Several small molecule inhibitors, short peptides, antibodies, and antibody drug conjugates have been developed for the purposes of more effective targeting and killing of malignant cells expressing CXCR4. In this review we will discuss recent results and strategies in targeting CXCR4 with these agents in patients with AML or ALL
Mobilized peripheral blood: An updated perspective
Enforced egress of hematopoietic stem cells (HSCs) out of the bone marrow (BM) into the peripheral circulation, termed mobilization, has come a long way since its discovery over four decades ago. Mobilization research continues to be driven by the need to optimize the regimen currently available in the clinic with regard to pharmacokinetic and pharmacodynamic profile, costs, and donor convenience. In this review, we describe the most recent findings in the field and how we anticipate them to affect the development of mobilization strategies in the future. Furthermore, the significance of mobilization beyond HSC collection, i.e. for chemosensitization, conditioning, and gene therapy as well as a means to study the interactions between HSCs and their BM microenvironment, is reviewed. Open questions, controversies, and the potential impact of recent technical progress on mobilization research are also highlighted
Innovations in hematopoietic stem-cell mobilization: A review of the novel CXCR4 inhibitor motixafortide
Hematopoietic stem-cell transplantation (HCT) and stem-cell-based gene therapies rely on the ability to collect sufficient CD34+ hematopoietic stem and progenitor cells (HSPCs), typicall
Crystal Symmetry Lowering in Chiral Multiferroic BaTaFeSiO observed by X-Ray Magnetic Scattering
Chiral multiferroic langasites have attracted attention due to their
doubly-chiral magnetic ground state within an enantiomorphic crystal. We report
on a detailed resonant soft X-ray diffraction study of the multiferroic
BaTaFeSiO at the Fe and oxygen edges. Below
() we observe the satellite reflections ,
, and where . The dependence of the scattering intensity on X-ray polarization and
azimuthal angle indicate that the odd harmonics are dominated by the
out-of-plane (-axis) magnetic dipole while the
originates from the electron density distortions accompanying magnetic order.
We observe dissimilar energy dependences of the diffraction intensity of the
purely magnetic odd-harmonic satellites at the Fe edge. Utilizing
first-principles calculations, we show that this is a consequence of the loss
of threefold crystal symmetry in the multiferroic phase
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