Toward a More Apparent Approach to Considering the Admission of Expert Testimony

This Article highlights lingering confusion in the caselaw as to the proper standard for the trial court’s discharge of its gatekeeping role for the admission of expert testimony. The Article urges correction of the faulty application of Daubert’s admonition as to “shaky but admissible” evidence as a substitute for proper discharge of the trial court’s gatekeeper function under Rule 104(a). The Article concludes with several suggestions for trial and appellate courts to consider for better decisionmaking in discharging their duty to apply Rule 104(a)’s preponderance standard to the elements of Rule 702

Atomic Structure of Domain and Interphase Boundaries in Ferroelectric HfO₂

Though ferroelectric HfO₂ thin films are now well characterized, little is currently known about their grain substructure. In particular, the formation of domain and phase boundaries requires investigation to better understand phase stabilization, switching, and phase interconversion. Here, scanning transmission electron microscopy is applied to investigate the atomic structure of boundaries in these materials. It is found that orthorhombic/orthorhombic domain walls and coherent orthorhombic/monoclinic interphase boundaries form throughout individual grains. The results inform how interphase boundaries can impose strain conditions that may be key to phase stabilization. Moreover, the atomic structure near interphase boundary walls suggests potential for their mobility under bias, which has been speculated to occur in perovskite morphotropic phase boundary systems by mechanisms similar to domain boundary motion

New Records of Deep-Water Cnidaria (Scleractinia & Antipatharia) from the Gulf of Mexico

Slxty·three species of azooxanthellate scleractinians and 26 species of antipatharians are recorded from the Gulf of Mexico. This report constitutes the first Inventory of Antipatharia within the geographic boundaries of the Gulf of Mexico whose southern limits are the Yucatan Straits to the south and the Florida Straits to the east. Thirteen range extensions of azooxanthellate species of the Order Scleractinia, and 28 species of the Order Antipatharia are reported. With respect to new records, we report four new records of azooxanthelate scleractinians and six new records of antipatharians from the outer continental shelf. One of the species, Slbopathes macrosplna Opresko, 1993, represents a new species In the western Atlantic region and appears related to Sibopathes gephura Van Pesch, 1914. The Gulf scleractinian fauna constitutes 54% of those known from the western Atlantic; the antipatharian fauna constitutes 93% of the western Atlantic fauna. These two groups are most diverse (55-56 species) in the regions of the Gulf adjacent to the Caribbean Sea and Atlantic Ocean (subdivisions I and VI). Diversity gradually decreases towards the western Gulf. Only six species are known from subdivision IV (east Mexico shelf and slope) and 23 species are recorded from subdivision V (Campeche Bank, Mexico)

Recent progress for obtaining the ferroelectric phase in hafnium oxide based films: impact of oxygen and zirconium

Different causes for ferroelectric properties in hafnium oxide were discussed during the last decade including various dopants, stress, electrode materials, and surface energy from different grain sizes. Recently, the focus shifted to the impact of oxygen vacancies on the phase formation process. In this progress report, the recent understanding of the influence of oxygen supplied during deposition on the structural phase formation process is reviewed and supplemented with new data for mixed HfₓZr₁₋ₓOᵧ films. Even though polar and non-polar HfₓZr₁₋ₓOᵧ thin films are well characterized, little is known about the impact of oxygen exposure during the deposition process. Here, a combination of structural and electrical characterization is applied to investigate the influence of the oxygen and zirconium content on the crystallization process during ALD deposition in comparison to other deposition techniques. Different polarization properties are assessed which correlate to the determined phase of the film. Optimized oxygen pulse times can enable the crystallization of HfₓZr₁₋ₓOᵧ in a polar orthorhombic phase rather than a non-polar monoclinic and tetragonal phase

Rotavirus NSP4: Cell Type-dependent Transport Kinetics to the Exofacial Plasma Membrane and Release from Intact Infected Cells

Background Rotavirus NSP4 localizes to multiple intracellular sites and is multifunctional, contributing to RV morphogenesis, replication and pathogenesis. One function of NSP4 is the induction of early secretory diarrhea by binding surface receptors to initiate signaling events. The aims of this study were to determine the transport kinetics of NSP4 to the exofacial plasma membrane (PM), the subsequent release from intact infected cells, and rebinding to naïve and/or neighboring cells in two cell types. Methods Transport kinetics was evaluated using surface-specific biotinylation/streptavidin pull-downs and exofacial exposure of NSP4 was confirmed by antibody binding to intact cells, and fluorescent resonant energy transfer. Transfected cells similarly were monitored to discern NSP4 movement in the absence of infection or other viral proteins. Endoglycosidase H digestions, preparation of CY3- or CY5- labeled F(ab)2 fragments, confocal imaging, and determination of preferential polarized transport employed standard laboratory techniques. Mock-infected, mock-biotinylated and non-specific antibodies served as controls. Results Only full-length (FL), endoglycosidase-sensitive NSP4 was detected on the exofacial surface of two cell types, whereas the corresponding cell lysates showed multiple glycosylated forms. The C-terminus of FL NSP4 was detected on exofacial-membrane surfaces at different times in different cell types prior to its release into culture media. Transport to the PM was rapid and distinct yet FL NSP4 was secreted from both cell types at a time similar to the release of virus. NSP4-containing, clarified media from both cells bound surface molecules of naïve cells, and imaging showed secreted NSP4 from one or more infected cells bound neighboring cell membranes in culture. Preferential sorting to apical or basolateral membranes also was distinct in different polarized cells. Conclusions The intracellular transport of NSP4 to the PM, translocation across the PM, exposure of the C-terminus on the cell surface and subsequent secretion occurs via an unusual, complex and likely cell-dependent process. The exofacial exposure of the C-terminus poses several questions and suggests an atypical mechanism by which NSP4 traverses the PM and interacts with membrane lipids. Mechanistic details of the unconventional trafficking of NSP4, interactions with host-cell specific molecules and subsequent release require additional study