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While the mitigating effects of trees on shallow landslide occurrence are well recognised, the impact of landslides on tree community structure and tree-tree interactions have received much less research attention. The structures of tree communities before and after landslides were compared in a 25-ha subtropical forest plot. Tree-tree interactions were examined by analysing the pre- and post-landslide spatial point patterns of large (DBH ≥ 20 cm) and small (1 cm ≤ DBH < 20 cm) tree cohorts. In landslide scarps, 35 (34%) of 104 large trees and 467 (13%) of 3.072 small trees survived. Large (L) and small (S) tree cohorts were paired together for spatial analyses, including pre-landslide (PL) (LPL-SPL), surviving (S) (LS-SS), and missing (M) large-small tree paired cohorts (LM-SM). We randomly selected trees from the pre-landslide tree cohorts to create two virtual paired cohorts, the L34%-S13% and L66%-S87% paired cohorts, whose population sizes were identical to the field-observed LS-SS and LM-SM paired cohorts respectively, but with random spatial patterns. Post-landslide survival rates of trees increased monotonically with DBH. Large trees dislodged by landslides scarcely reduced small-tree survival. Evidence for this included: (i) the distance from small trees to the nearest large trees of the LM-SM paired cohort did not differ significantly from that of the virtual L66%-S87% paired cohort; (ii) survival rates of small trees near LM individuals did not differ significantly from those without large trees nearby. Surviving large trees had positive effects on the survival of small trees, indicated by: (i) the distance from small trees to the nearest large trees of the LS-SS paired cohort was significantly lower than that of the virtual L34%-S13% paired cohort; (ii) SS individuals clumped around LS individuals, whereas the virtual L34%-S13% spatial relationship was random. Large trees prevent landslide dislodgement of adjacent small trees through the nurse-plant effect. Our study suggests that landslide damage in sloping forests may be reduced simply by constantly maintaining a critical density of large trees.

We explore the hypothesis that pathology of Huntington's disease involves multiple cellular mechanisms whose contributions to disease are incrementally additive or synergistic. We provide evidence that the photoreceptor neuron degeneration seen in flies expressing mutant human huntingtin correlates with widespread degenerative events in the Drosophila CNS. We use a Drosophila Huntington's disease model to establish dose regimens and protocols to assess the effectiveness of drug combinations used at low threshold concentrations. These proof of principle studies identify at least two potential combinatorial treatment options and illustrate a rapid and cost-effective paradigm for testing and optimizing combinatorial drug therapies while reducing side effects for patients with neurodegenerative disease. The potential for using prescreening in Drosophila to inform combinatorial therapies that are most likely to be effective for testing in mammals is discussed.

Domain microstructures in single crystal lamellae of 88%Pb(Zn1/3Nb2/3)O3-12%PbTiO3 (cut from bulk using focused ion beam milling) have been mapped using both piezoresponse force microscopy and transmission electron microscopy. Dramatic changes from mottled microstructures typical of relaxors to larger scale domains typical of ferroelectrics have been noted. Stresses associated with substrate clamping are suspected as the cause for the transition from short- to long-range polar order, akin to effects induced by cation ordering achieved by thermal quenching. [ABSTRACT FROM AUTHOR]

Domain microstructures in single crystal lamellae of 88%Pb(Zn1/3Nb2/3)O3-12%PbTiO3 (cut from bulk using focused ion beam milling) have been mapped using both piezoresponse force microscopy and transmission electron microscopy. Dramatic changes from mottled microstructures typical of relaxors to larger scale domains typical of ferroelectrics have been noted. Stresses associated with substrate clamping are suspected as the cause for the transition from short- to long-range polar order, akin to effects induced by cation ordering achieved by thermal quenching. [ABSTRACT FROM AUTHOR]

Te-doped and ZnTe-doped diluted ZnSeTe samples were grown by using metal-organic chemical vapor deposition. The green lights emitted from these two samples in the photoluminescence (PL) measurement have different peak emission energies and can be attributed to different emission mechanisms. For the Te-doped sample, the PL emission band is excitation laser power independent, the lifetime of the PL emission is short, and the PL emission could be attributed to the emission originated from Te isoelectronic centers. For the ZnTe-doped sample, the energy of the green emission band is laser power dependent, the PL lifetime is much longer than the Te-doped sample, and the PL emission could be attributed to the emission from type-II ZnTe/ZnSe quantum dots. The results demonstrate that there are two different mechanisms responsible for the green PL emission in ZnSeTe system and our growth methods provide a way of selecting one of the two mechanisms for the green light emission in this system. [ABSTRACT FROM AUTHOR]