4,908 research outputs found
Evidence for multiple structural genes for the Îł chain of human fetal hemoglobin
A sequence with a specific residue at each position was proposed for the Îł chain of human fetal hemoglobin by Schroeder et al. (1) after a study in which hemoglobin from a number of individual infants was used. We have now examined in part the fetal hemoglobin components of 17 additional infants and have observed that position 136 of the Îł chain may be occupied not only by a glycyl residue, as previously reported, but also by an alanyl residue
Truncated Variational Sampling for "Black Box" Optimization of Generative Models
We investigate the optimization of two probabilistic generative models with
binary latent variables using a novel variational EM approach. The approach
distinguishes itself from previous variational approaches by using latent
states as variational parameters. Here we use efficient and general purpose
sampling procedures to vary the latent states, and investigate the "black box"
applicability of the resulting optimization procedure. For general purpose
applicability, samples are drawn from approximate marginal distributions of the
considered generative model as well as from the model's prior distribution. As
such, variational sampling is defined in a generic form, and is directly
executable for a given model. As a proof of concept, we then apply the novel
procedure (A) to Binary Sparse Coding (a model with continuous observables),
and (B) to basic Sigmoid Belief Networks (which are models with binary
observables). Numerical experiments verify that the investigated approach
efficiently as well as effectively increases a variational free energy
objective without requiring any additional analytical steps
Cultural Resources Survey for the City of Florence Municipal Facilities Complex Project, Williamson County, Texas
On behalf of the City of Florence, Texas, SWCA Environmental Consultants (SWCA) conducted an intensive cultural resources survey of the proposed City of Florence Municipal Facilities Complex (Project) in Williamson County, Texas. The 1.2-acre parcel scheduled for redevelopment is located on land owned and managed by the City of Florence, a political subdivision of the state of Texas; therefore, the Project requires compliance with the Antiquities Code of Texas (ACT). In addition, the project will receive federal funds from the U.S. Department of Agriculture (USDA); therefore, the work was conducted to comply with the National Historic Preservation Act (NHPA). This cultural resources investigation was conducted under ACT Permit No. 9142. On behalf of the USDA, SWCA has also issued engagement letters to the six Tribes identified by the U.S. Department of Housing and Urban Development (HUD) as having overlapping interest with the Project area. To date, SWCA has yet to receive comments from the identified Tribes.
The parcel on which the Project is proposed contains four extant buildings/structures: the Florence City Hall, the Chamber of Commerce, a large Veteran’s Memorial, and a thrift store. As part of the Project, all but the Veteran’s Memorial are scheduled for demolition and a larger municipal complex is expected to be constructed in their stead. Impacts are expected to include widespread surficial modifications with deeper impacts in locations of foundations and utilities.
The cultural resources investigation consisted of a background and historical map review followed by intensive pedestrian survey augmented by shovel testing conducted by an archaeologist, and an assessment of the extant buildings conducted by an architectural historian. SWCA’s background review determined that there are no known cultural resources within the Project area. Additionally, the historical map review identified only two potential historical structures within the Project area.
During field investigations on September 25 and November 5, 2019, SWCA confirmed that the four extant buildings/structures on the subject property are of modern construction, and therefore, are not eligible for the National Register of Historic Places (NRHP) and are not considered eligible for designation as a State Antiquities Landmark (SAL). In addition, the two potential historical structures identified during the historical map review within the Project area are not extant. SWCA excavated a total of 12 shovel tests within the Project area, three of which were positive for cultural materials. The cultural material includes an axe head, an unidentifiable metal fragment, a round nail, and a white-bodied earthenware sherd. The artifacts found within the shovel tests cannot be securely identified as being from a historic origin and were found with, or near the same depth as, modern plastic fragments. Furthermore, the soils within the Project area exhibited a high degree of disturbance due to decades of construction, landscaping, and tree planting, as well as buried utilities. Due to the lack of soil integrity and the lack of artifacts that can securely be attributed to a historic origin, SWCA finds the three positive shovel tests as constituting an isolated find and does not rise to the level of an archaeological site. As such, the isolated finds do not meet the criteria for NRHP listing nor SAL designation. No other cultural resources were identified within the Project area.
In accordance with the ACT and with Section 106 of the NHPA (36 Code of Federal Regulations [CFR] 800.4 (b)(1)), SWCA has made a reasonable and good faith effort to identify historic properties within the area of potential effects. SWCA recommends a finding of No Historic Properties Affected per 36 CFR 800. 5(b) and no further archaeological investigation of the current Project area is recommended. No artifacts or samples were collected during this survey. All survey-related documentation will be curated at the Center for Archaeological Studies, Texas State University, San Marcos, Texas
AS-777-14 Resolution on Proposal to Establish the Strawberry Sustainability Research and Education Center
That the Academic Senate endorses the establishment of the Strawberry Sustainability Research Education Center
NS-NS fluxes in Hitchin's generalized geometry
The standard notion of NS-NS 3-form flux is lifted to Hitchin's generalized
geometry. This generalized flux is given in terms of an integral of a modified
Nijenhuis operator over a generalized 3-cycle. Explicitly evaluating the
generalized flux in a number of familiar examples, we show that it can compute
three-form flux, geometric flux and non-geometric Q-flux. Finally, a
generalized connection that acts on generalized vectors is described and we
show how the flux arises from it.Comment: 21 pages, 1 figure; v3: minor change
Transition of Attention in Terminal Area NextGen Operations Using Synthetic Vision Systems
This experiment investigates the capability of Synthetic Vision Systems (SVS) to provide significant situation awareness in terminal area operations, specifically in low visibility conditions. The use of a Head-Up Display (HUD) and Head-Down Displays (HDD) with SVS is contrasted to baseline standard head down displays in terms of induced workload and pilot behavior in 1400 RVR visibility levels. Variances across performance and pilot behavior were reviewed for acceptability when using HUD or HDD with SVS under reduced minimums to acquire the necessary visual components to continue to land. The data suggest superior performance for HUD implementations. Improved attentional behavior is also suggested for HDD implementations of SVS for low-visibility approach and landing operations
Nongeometry, Duality Twists, and the Worldsheet
In this paper, we use orbifold methods to construct nongeometric backgrounds,
and argue that they correspond to the spacetimes discussed in \cite{dh,wwf}.
More precisely, we make explicit through several examples the connection
between interpolating orbifolds and spacetime duality twists. We argue that
generic nongeometric backgrounds arising from duality twists will not have
simple orbifold constructions and then proceed to construct several examples
which do have a consistent worldsheet description.Comment: v2-references added; v3-minor correction (eqn. 4.17
D-Terms from Generalized NS-NS Fluxes in Type II
Orientifolds of type II string theory admit a certain set of generalized
NS-NS fluxes, including not only the three-form field strength H, but also
metric and non-geometric fluxes, which are related to H by T-duality. We
describe in general how these fluxes appear as parameters of an effective N=1
supergravity theory in four dimensions, and in particular how certain
generalized NS-NS fluxes can act as charges for R-R axions, leading to D-term
contributions to the effective scalar potential. We illustrate these phenomena
in type IIB with the example of a certain orientifold of T^6/Z_4.Comment: 31+1 pages, uses utarticle.cls; v2: references adde
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