Dynamical Masses for Pre-Main Sequence Stars: A Preliminary Physical Orbit for V773 Tau A

We report on interferometric and radial-velocity observations of the double-lined 51-d period binary (A) component of the quadruple pre-main sequence (PMS) system V773 Tau. With these observations we have estimated preliminary visual and physical orbits of the V773 Tau A subsystem. Among other parameters, our orbit model includes an inclination of 66.0 $\pm$ 2.4 deg, and allows us to infer the component dynamical masses and system distance. In particular we find component masses of 1.54 $\pm$ 0.14 and 1.332 $\pm$ 0.097 M_{\sun} for the Aa (primary) and Ab (secondary) components respectively. Our modeling of the subsystem component spectral energy distributions finds temperatures and luminosities consistent with previous studies, and coupled with the component mass estimates allows for comparison with PMS stellar models in the intermediate-mass range. We compare V773 Tau A component properties with several popular solar-composition models for intermediate-mass PMS stars. All models predict masses consistent to within 2-sigma of the dynamically determined values, though some models predict values that are more consistent than others.Comment: ApJ in press; 25 pages, 6 figures; data tables available in journal versio

Intradermal Electroporation of Naked Replicon RNA Elicits Strong Immune Responses

RNA-based vaccines represent an interesting immunization modality, but suffer from poor stability and a lack of efficient and clinically feasible delivery technologies. This study evaluates the immunogenic potential of naked in vitro transcribed Semliki Forest virus replicon RNA (RREP) delivered intradermally in combination with electroporation. Replicon-immunized mice showed a strong cellular and humoral response, contrary to mice immunized with regular mRNA. RREP-elicited induction of interferon-γ secreting CD8+ T cells and antibody responses were significantly increased by electroporation. CD8+ T cell responses remained substantial five weeks post vaccination, and antigen-specific CD8+ T cells with phenotypic characteristics of both effector and central memory cells were identified. The immune response during the contraction phase was further increased by a booster immunization, and the proportion of effector memory cells increased significantly. These results demonstrate that naked RREP delivered via intradermal electroporation constitute an immunogenic, safe and attractive alternative immunization strategy to DNA-based vaccines

Estuarine Beaches

xvi,225 hal,;ill,;21 c

Opportunities and constraints for managed retreat on exposed sandy shores: Examples from Emilia-Romagna, Italy

Managed retreat is rarely implemented on exposed sandy coasts because of public interest in beach recreation and the great human-use value of existing beaches and dunes. The feasibility of retreat on the sandy coast of the Adriatic Sea in the Region of Emilia-Romagna was evaluated at a site with a single user facility (a beach concession) backed by public parkland. A conceptual scenario of changes to landforms and habitats was developed for the retreat option. Interviews with key stakeholders revealed perceptions of alternatives for addressing erosion and flooding by managed retreat or by protecting existing features in place. The beach concession occupies a segment of shore between an eroding (-9.3 m yr(-1)) washover barrier updrift and an accreting beach downdrift. Landward of the concession is a portion of the Po Delta Park, consisting of a brackish lagoon and marsh and an artificially-created freshwater lake. Shore protection projects have maintained the concession and the integrity of a dike protecting the lake. Allowing retreat to occur would cause (1) loss of the concession in its present location; (2) erosion of the dike, converting the lake to brackish habitat; and (3) migration of the shoreline to a pine forest, campground and residences that are now 500 m from the shoreline. Freshwater and pine forest habitat would be lost, but salt water wetland and pioneer coastal species would be restored. The beach and campground could still be used as the shoreline migrates inland, but with less fixed infrastructure. Landward facilities could be protected by a ring dike. At issue is whether normally dynamic and short-term landforms and habitats should be protected as static features in perpetuity and whether human actions should be taken to protect human-created nature (lake, pine forest) against natural evolutionary processes. Stakeholders indicated that managed retreat should occur eventually but existing features should be protected now. The retreat option is compatible with Regional ICZM plans, but differs from the standard engineering designs actually suggested for implementation. The benefits of managed retreat on exposed sandy shores can only be presented in conceptual terms until demonstration projects provide concrete answers, so it is not surprising that the undocumented benefits of a more dynamic shoreline have little appeal relative to maintaining the status quo

VARIABLE PRE-EMPHASIS LPC FOR MODELING VOCAL EFFORT IN THE SINGING VOICE

In speech and singing, the spectral envelope of the glottal source varies according to different voice qualities such as vocal effort, lax voice, and breathy voice. In contrast, linear prediction coding (LPC) models the glottal source in a way that is not flexible. The spectral envelope of the source estimated by LPC is fixed and determined by the pre-emphasis filter. In standard LPC, the formant filter captures variation in the spectral envelope that should be associated with the source. This paper presents variable preemphasis LPC (VPLPC) as a technique to allow the estimated source to vary. This results in formant filters that remain more consistent across variations in vocal effort and breathiness. VPLPC also provides a way to change the envelope of the estimated source, thereby changing the perception of vocal effort. The VPLPC algorithm is used to manipulate some voice excerpts with promising but mixed results. Possible improvements are suggested. 1

Influence of the LPC filter upon the perception of breathiness and vocal effort

According to the source-filter paradigm, the perception of breathiness and vocal effort should be primarily controlled by the glottal source and be little affected by the formant filter. This experiment investigates whether the formant filter estimated by linear prediction (LPC) can influence the perception of breathiness and vocal effort. The experiment starts with a pair of voice samples. One sample exhibits high effort and the other sample exhibits breathiness. LPC estimates a filter and residual for each sample. The influence of the residual is eliminated by providing both filters with the same artificial source during resynthesis. The synthesized samples differ only according to the difference between the two filters. Three pairs of samples were evaluated by seven people in listening tests. The results demonstrate that the LPC filters do influence the perception of breathiness and vocal effort. When a voice changes between breathiness and vocal effort, the spectral envelope changes. This change is captured by the LPC filter rather than the residual. A closer look at the LPC algorithm provides an explanation for this result. 1

Facilitating landform migration by removing shore protection structures: Opportunities and constraints

Recent studies have identified the need to adapt to climate change by allowing landforms and habitats to migrate landward, although implementation of actual adaptation responses is limited. Removing the barriers that shore protection structures create between coastal and upland habitats can reestablish exchanges of sediment and the ecological functions of the natural ecotone. The potential for removing these structures was evaluated in 12 national parks managed by the U.S. National Park Service. Criteria for removal included condition of structures, influence of natural processes, environmental benefits, public safety, and visitor access and use. We found that 145 structures out of a total of 407 could be removed or allowed to deteriorate. We highlight three adaptation projects that are currently being conducted, two of which involve removing structures. Reasons for not taking a more pro-active approach to removing protection structures include (1) conflicting policy directives; (2) presence of key access roads and critical archaeological and historic sites; (3) lack of data; (4) lack of funds and human resources; (5) reluctance to replace known problems with an unknown set of problems; (6) consideration of visitor desires; and (7) reluctance to allow erosion to occur. Demonstration projects are needed to provide information about adaptation strategies that promote enhancement of ecosystem functions. Projects to remove protection structures are likely to be viewed as successful only if results are specified as a positive product, and the distinction between the concept of loss (erosion of existing landforms and habitats) and the concept of gain (evolution of new landforms and habitats) is made clear