cssi/SciSciGPT-SciSciNet huggingface dataset:
Vehicular Teamwork: Collaborative localization of Autonomous Vehicles

This paper develops a distributed collaborative localization algorithm based on an extended kalman filter. This algorithm incorporates Ultra-Wideband measurements for vehicle to vehicle ranging, and shows improvements in localization accuracy where GPS typically falls short. The algorithm was first tested in a newly created open-source simulation environment that emulates various numbers of vehicles and sensors while simultaneously testing multiple localization algorithms. Predicted error distributions for various algorithms are quickly producible using the Monte-Carlo method and optimization techniques within MatLab. The simulation results were validated experimentally in an outdoor, urban environment. Improvements of localization accuracy over a typical extended kalman filter ranged from 2.9% to 9.3% over 180 meter test runs. When GPS was denied, these improvements increased up to 83.3 % over a standard kalman filter. In both simulation and experimentally, the Decentralized Collaborative Localization algorithm was shown to be a good approximation of a full state filter, while reducing required communication between vehicles. These results are promising in showing the efficacy of adding UWB ranging sensors to cars for collaborative and landmark localization, especially in GPS-denied environments. In the future, additional moving vehicles with additional tags will be tested in other challenging GPS denied environments.
Autobahn: Automorphism-based Graph Neural Nets

We introduce Automorphism-based graph neural networks (Autobahn), a new family of graph neural networks. In an Autobahn, we decompose the graph into a collection of subgraphs and apply local convolutions that are equivariant to each subgraph's automorphism group. Specific choices of local neighborhoods and subgraphs recover existing architectures such as message passing neural networks. Our formalism also encompasses novel architectures: as an example, we introduce a graph neural network that decomposes the graph into paths and cycles. The resulting convolutions reflect the natural way that parts of the graph can transform, preserving the intuitive meaning of convolution without sacrificing global permutation equivariance. We validate our approach by applying Autobahn to molecular graphs, where it achieves state-of-the-art results.
Phrase-BERT: Improved Phrase Embeddings from BERT with an Application to Corpus Exploration

Phrase representations derived from BERT often do not exhibit complex phrasal compositionality, as the model relies instead on lexical similarity to determine semantic relatedness. In this paper, we propose a contrastive fine-tuning objective that enables BERT to produce more powerful phrase embeddings. Our approach (Phrase-BERT) relies on a dataset of diverse phrasal paraphrases, which is automatically generated using a paraphrase generation model, as well as a large-scale dataset of phrases in context mined from the Books3 corpus. Phrase-BERT outperforms baselines across a variety of phrase-level similarity tasks, while also demonstrating increased lexical diversity between nearest neighbors in the vector space. Finally, as a case study, we show that Phrase-BERT embeddings can be easily integrated with a simple autoencoder to build a phrase-based neural topic model that interprets topics as mixtures of words and phrases by performing a nearest neighbor search in the embedding space. Crowdsourced evaluations demonstrate that this phrase-based topic model produces more coherent and meaningful topics than baseline word and phrase-level topic models, further validating the utility of Phrase-BERT.
Explaining Autonomous Decisions in Swarms of Human-on-the-Loop Small Unmanned Aerial Systems.

Rapid advancements in Artificial Intelligence have shifted the focus from traditional human-directed robots to fully autonomous ones that do not require explicit human control. These are commonly referred to as Human-on-the-Loop (HotL) systems. Transparency of HotL systems necessitates clear explanations of autonomous behavior so that humans are aware of what is happening in the environment and can understand why robots behave in a certain way. However, in complex multi-robot environments, especially those in which the robots are autonomous and mobile, humans may struggle to maintain situational awareness. Presenting humans with rich explanations of autonomous behavior tends to overload them with lots of information and negatively affect their understanding of the situation. Therefore, explaining the autonomous behavior of multiple robots creates a design tension that demands careful investigation. This paper examines the User Interface (UI) design trade-offs associated with providing timely and detailed explanations of autonomous behavior for swarms of small Unmanned Aerial Systems (sUAS) or drones. We analyze the impact of UI design choices on human awareness of the situation. We conducted multiple user studies with both inexperienced and expert sUAS operators to present our design solution and initial guidelines for designing the HotL multi-sUAS interface.
Spherical vs. Non-Spherical and Symmetry-Preserving vs. Symmetry-Breaking Densities of Open-Shell Atoms in Density Functional Theory

The atomization energies of molecules from first-principles density functional approximations improve from the local spin-density approximation (LSDA) to the Perdew-Burke-Ernzerhof (PBE)) generalized gradient approximation (GGA) to the strongly constrained and appropriately normed (SCAN) meta-GGA, and their sensitivities to non-spherical components of the density increase in the same order. Thus, these functional advances increase density sensitivity and imitate the exact constrained search over correlated wavefunctions better than that over ensembles. The diatomic molecules studied here, singlet C2 and F2 plus triplet B2 and O2, have cylindrically symmetric densities. Because the densities of the corresponding atoms are non-spherical, the approximate Kohn-Sham potentials for the atoms have a lower symmetry than that of the external (nuclear) potential, so that the non-interacting wavefunctions are not eigenstates of the square of total orbital angular momentum, breaking a symmetry that yields a feature of the exact ground-state density. That spatial symmetry can be preserved by a non-self-consistent approach in which a self-consistent equilibrium-ensemble calculation is followed by integer re-occupation of the Kohn-Sham orbitals, as the first of several steps. The symmetry-preserving approach is different from symmetry restoration based upon projection. First-step space- (and space-spin-) symmetry preservation in atoms is shown to have a small effect on the atomization energies of molecules, quantifying earlier observations by Fertig and Kohn. Thus, the standard Kohn-Sham way of calculating atomization energies, with self-consistent symmetry breaking to minimize the energy, is justified, at least for the common cases where the molecules cannot break the symmetry.
Automated, Targeted Testing of Property-Based Testing Predicates

Context: This work is based on property-based testing (PBT). PBT is an increasingly important form of software testing. Furthermore, it serves as a concrete gateway into the abstract area of formal methods. Specifically, we focus on students learning PBT methods. Inquiry: How well do students do at PBT? Our goal is to assess the quality of the predicates they write as part of PBT. Prior work introduced the idea of decomposing the predicate's property into a conjunction of independent subproperties. Testing the predicate against each subproperty gives a "semantic" understanding of their performance. Approach: The notion of independence of subproperties both seems intuitive and was an important condition in prior work. First, we show that this condition is overly restrictive and might hide valuable information: it both undercounts errors and makes it hard to capture misconceptions. Second, we introduce two forms of automation, one based on PBT tools and the other on SAT-solving, to enable testing of student predicates. Third, we compare the output of these automated tools against manually-constructed tests. Fourth, we also measure the performance of those tools. Finally, we re-assess student performance reported in prior work. Knowledge: We show the difficulty caused by the independent subproperty requirement. We provide insight into how to use automation effectively to assess PBT predicates. In particular, we discuss the steps we had to take to beat human performance. We also provide insight into how to make the automation work efficiently. Finally, we present a much richer account than prior work of how students did. Grounding: Our methods are grounded in mathematical logic. We also make use of well-understood principles of test generation from more formal specifications. This combination ensures the soundness of our work. We use standard methods to measure performance. Importance: As both educators and programmers, we believe PBT is a valuable tool for students to learn, and its importance will only grow as more developers appreciate its value. Effective teaching requires a clear understanding of student knowledge and progress. Our methods enable a rich and automated analysis of student performance on PBT that yields insight into their understanding and can capture misconceptions. We therefore expect these results to be valuable to educators.
Asymmetric one-dimensional slow electron holes

Slow solitary positive-potential peaks sustained by trapped electron deficit in a plasma with asymmetric ion velocity distributions are in principle asymmetric, involving a potential change across the hole. It is shown theoretically how to construct such asymmetric electron holes, thus providing fully consistent solutions of the one-dimensional Vlasov-Poisson equation for a wide variety of prescribed background ion velocity distributions. Because of ion reflection forces experienced by the hole, there is generally only one discrete slow hole velocity that is in equilibrium. Moreover the equilibrium is unstable unless there is a local minimum in the ion velocity distribution, in which the hole velocity then resides. For stable equilibria with Maxwellian electrons, the potential drop across the hole is shown to be $\Delta\phi\simeq{2\over 9}f'''{T_e\over e}({e\psi\over m_i})^2$, where $\psi$ is the hole peak potential, $f'''$ is the third derivative of the background ion velocity distribution function at the hole velocity, and $T_e$ the electron temperature. Potential asymmetry is small for holes of the amplitudes usually observed, $\psi\lesssim 0.5T_e/e$.
Mast Cells Play an Important Role in Chlamydia pneumoniae Lung Infection by Facilitating Immune Cell Recruitment into the Airway

Mast cells are known as central players in allergy and anaphylaxis, and they play a pivotal role in host defense against certain pathogens. Chlamydia pneumoniae is an important human pathogen, but it is unclear what role mast cells play during C. pneumoniae infection. We infected C57BL/6 (wild-type [WT]) and mast cell-deficient mice (Kit(W-sh/W-sh) [Wsh]) with C. pneumoniae. Wsh mice showed improved survival compared with WT mice, with fewer cells in Wsh bronchoalveolar lavage fluid (BALF), despite similar levels of cytokines and chemokines. We also found a more rapid clearance of bacteria from the lungs of Wsh mice compared with WT mice. Cromolyn, a mast cell stabilizer, reduced BALF cells and bacterial burden similar to the levels seen in Wsh mice; conversely, Compound 48/80, a mast cell degranulator, increased the number of BALF cells and bacterial burden. Histology showed that WT lungs had diffuse inflammation, whereas Wsh mice had patchy accumulations of neutrophils and perivascular accumulations of lymphocytes. Infected Wsh mice had reduced amounts of matrix metalloprotease-9 in BALF and were resistant to epithelial integral membrane protein degradation, suggesting that barrier integrity remains intact in Wsh mice. Mast cell reconstitution in Wsh mice led to enhanced bacterial growth and normal epithelial integral membrane protein degradation, highlighting the specific role of mast cells in this model. These data suggest that mast cells play a detrimental role during C. pneumoniae infection by facilitating immune cell infiltration into the airspace and providing a more favorable replicative environment for C. pneumoniae.
Feedback Loop Design and Analysis for Iterative Localized Image Deblurring

This paper considers image deblurring algorithm based on model-based iterative update of the image estimate. The update has two principal terms: (i) integral feedback of blurred image prediction error and (ii) feedback of the past deblurred image estimate. The two feedback terms are computed by applyingtwo FIR operators. The paper shows how these feedback update operators can de designed with a given degree of localization to provide an optimal tradeoff between design objectives such as convergence speed, noise amplification, quality of image restoration, and robustness. The solution to the feedback operator design problem is obtained by Linear Programming optimization. A parallelized implementation of the update algorithm using localized feedback operators is scalable to very large image sizes.
Retrocyclins: Novel Circular Peptides Active Against HIV-1

Heterosexual transmission through mucosal surfaces is one of the most common routes of HIV-1 spread. Topical microbicides are self-applied prophylactic agents, used to prevent vaginal and other mucosal transmission of HIV-1, which have the advantage of empowering vulnerable receptive partners to take effective measures for their own protection. In a search for candidate topical microbicides we discovered that retrocyclin, a unique θ-defensin synthetically constructed based on sequence data from its pseudogene, can potently prevent infection of CD4+ cells by both X4 and R5 HIV-1. While many studies have utilized simulants of mucosal fluid to test compounds, we are studying how whole human vaginal fluid and its functional components affect the activity and stability of peptide-based microbicides. We explored a novel, physiologically relevant approach to assess the ability of a candidate retrocyclin microbicide, RC-101, to inhibit HIV-1 infection of immunocompetent human cervicovaginal tissue. We revealed that 1) using a novel proteomic approach, human vaginal fluid contained at least 20 different cationic (poly)peptides with purported roles in innate host defense, 2) the cationic polypeptide fraction of vaginal fluid was required for innate anti-HIV-1 activity, 3) RC-101 retained full anti-HIV-1 activity in the presence of whole human vaginal fluid, 4) when applied apically to organotypical cervicovaginal epithelium, RC101 was retained in the tissue, and 5) RC-101 prevented HIV-1 infection of immunocompetent organotypic cervicovaginal epithelium. Collectively, we have characterized the innate antiviral host defense factors within vaginal fluid, and developed a highly relevant ex vivo vaginal model suitable for peptide-based microbicide evaluation. from 2005 International Meeting of The Institute of Human Virology Baltimore, USA, 29 August – 2 September 2005
Frameworks for studying the determinants of child survival

Looking back the optimism of the early 1980s that child survival could be improved rapidly and at low cost in all lowincome settings was at best premature. Although immunization programmes have greatly increased immunization levels and oral rehydration has been effective at reducing deaths from diarrhoea in some settings child mortality declines in the 1980s were not noticeably faster than those of the 1970s. The Mosley–Chen model however has stood the test of time remarkably well and still provides explicitly or implicitly the conceptual basis for many studies of child survival. The underlying ideas have influenced a wide range of health research. The basic proximate determinants framework is very similar to the household health production function in economics. The proposal of a single health status outcome measure combining both morbidity and mortality is picked up in studies of disease burden in the 1990s. Mosley & Chen correctly predicted that it would not be possible to develop their framework into a readily-quantifiable model whereby the effect on child health status of a given change in one of the proximate determinants could be estimated (in the way that Bongaarts had developed Davis & Blake’s framework for the study of fertility). However social science research on child mortality has benefitted greatly from the clarity of the conceptual framework proposed by Moseley & Chen. As their paper concludes the framework permits research that “... can not only assess the overall health impact of alternative development strategies but also more sharply define which among a number of specific factors amenable to change by health policymakers are of greatest consequence for child survival.” This is just as true today as when the paper was written. (excerpt)
On the Planet and the Disk of COKU TAURI/4

Spitzer observations of the young star CoKu Tau/4 reveal a disk with a 10 AU hole that is most likely caused by a newly formed planet. Assuming that the planet opened a gap in the viscous disk, we estimate that the planet mass is greater than 0.1 Jupiter masses. This estimate depends on a lower limit to the disk viscosity derived from the timescale needed to accrete the inner disk, creating the now detectable hole. The planet migration timescale must at least modestly exceed the time for the spectrally inferred hole to clear. The proximity of the planet to the disk edge implied by our limits suggests that the latter is perturbed by the nearby planet and may exhibit a spiral pattern rotating with the planet. This pattern might be resolved with current ground-based mid-infrared cameras and optical cameras on the Hubble Space Telescope. The required submegayear planet formation may challenge core accretion formation models. However, we find that only if the planet mass is larger than about 10 Jupiter masses, allowing for a high enough surface density without inducing migration, would formation by direct gravitational instability be possible.
Improving diabetic foot care in a nurse-managed safety-net clinic

Purpose This article is a description of the development and implementation of a Comprehensive Diabetic Foot Care Program and assessment tool in an academically affiliated nurse-managed, multidisciplinary, safety-net clinic. The assessment tool parallels parameters identified in the Task Force Foot Care Interest Group of the American Diabetes Association's report published in 2008, “Comprehensive Foot Examination and Risk Assessment.” Data sources Review of literature, Silver City Health Center's (SCHC) 2009 Annual Report, retrospective chart review. Conclusions Since the full implementation of SCHC's Comprehensive Diabetic Foot Care Program, there have been no hospitalizations of clinic patients for foot-related complications. Implications for practice The development of the Comprehensive Diabetic Foot Assessment tool and the implementation of the Comprehensive Diabetic Foot Care Program have resulted in positive outcomes for the patients in a nurse-managed safety-net clinic. This article demonstrates that quality healthcare services can successfully be developed and implemented in a safety-net clinic setting.
Intra-patient Prone to Supine Colon Registration for Synchronized Virtual Colonoscopy

In this paper, we present an automated method for colon registration. The method uses dynamic programming to align data defined on colon center-line paths, as extracted from the prone and supine scans. This data may include information such as path length and curvature as well as descriptors of the shape and size of the colon near the path. We show how our colon registration technique can be used to produce synchronized fly-through or slice views.
Art to Capture Learning About the Longleaf Pine Ecosystem – Why a Picture Is Worth a Thousand Words

Nestled within 48,000 acres of privately owned conservation lands in the Florida Panhandle is an oasis for environmental learning – The E.O. Wilson Biophilia Center at Nokuse Plantation. The Center is the capstone to an ambitious environmental stewardship project, Nokuse Plantation, conceived and implemented by M.C. Davis, with the mission to create a model that connects the large-scale preservation of lands with experiential learning. The center serves as a catalyst for the preservation of nature’s biodiversity. Davis believes that the future of biodiversity lies in the combined resources of multiple actors and is best accomplished “by joining the passion of individuals with the resources of the entrepreneur and the power of government, all guided by science” (http://www.nokuse.org/).
THE HEALTH-RELATED QUALITY OF LIFE IN MOTHERS OF SURVIVING DEAF BLIND ADULT CHILDREN WITH CONGENITAL RUBELLA SYNDROME IN THE UNITED STATES

The purpose of this study was to determine the health related quality of life (HRQOL) of mothers of surviving deaf-blind adult children with congenital rubella syndrome (CRS) and the relationship of factors that influence it. This study uses a cross sectional design with all of the study participants having surviving CRS children born from the 1963-1965 epidemic. Analysis revealed: 1). Maternal CSI scores were significantly associated with the HRQOL F (13, 273) = 67.175 p< .001. Mothers who experienced high levels of caregiver stress had a poorer overall quality of life than those with lower levels of stress. 2).The deaf-blind adult child’s with CRS functional ability was significantly associated with the maternal HRQOL F (22, 263) = 17.03 p< .001. Mothers of adult deaf blind children needing care had poorer overall quality of life than those more independent. 3). Communication methods were significantly associated with the HRQOL. Communication with Sign Language (M= 80.39, SD= 20.8) demonstrated better overall maternal HRQOL scores than those with gestures (M= 31.49, SD= 32.57), F (8, 277) = 17.471, p < .001. 4). 4). Behaviors were significantly associated with the HRQOL with the largest difference between adult- children demonstrating no apparent behavior (M= 89.77, SD= 11.7) to those presenting aggressive behavior (M= 30.95, SD= 30.37), F (7, 279) =21.130 p < .001. As the prevalence of children with disabilities continues to increase, so does the demand for professionals who understand the unique needs of caregivers. Professionals must understand the impact special needs have on the mother and by extension, the family, and be able to provide the care and resources needed to support the continued care.
Adaptive force control in grasping as a function of level of developmental disability.

Background The adaptation to the task demands of grasping (grip mode and object mass) was investigated as a function of level of developmental disability. Methods Subjects grasped objects of different grip widths and masses that were instrumented to record grip forces. Results Proportionally, fewer participants from the profound compared with moderate and severe disability groups were able to complete the prehensile tasks. Nevertheless, all participants who completed the task showed adaptive grasping behaviour in terms of level and variability of force produced. There was higher absolute and relative force variability in low mass tasks that was enhanced with greater level of developmental disability. Conclusions The findings show task relevant adaptive grasping control with inhibition of force output at very-low-force conditions being the primary performance deficit of the profound disability group as a function of level of developmental disability.
Cloning and expression of transaldolase from potato

We have isolated a cDNA encoding transaldolase, an enzyme of the pentose-phosphate pathway, from potato (Solanum tuberosum). The 1.5 kb cDNA encodes a protein of 438 amino acid residues with a molecular mass of 47.8 kDa. When the potato cDNA was expressed in Escherichia coli a 45 kDa protein with transaldolase activity was produced. The first 62 amino acids of the deduced amino acid sequence represent an apparent plastid transit sequence. While the potato transaldolase has considerable similarity to the enzyme from cyanobacteria and Mycobacterium leprae, similarity to the conserved transaldolase enzymes from humans, E. coli and Saccharomyces cerevisiae is more limited. Northern analysis indicated that the transaldolase mRNA accumulated in tubers in response to wounding. Probing the RNA from various potato tissues indicated that the transaldolase mRNA accumulation to higher levels in the stem of mature potato plants than in either leaves or tubers. These data are consistent with a role for this enzyme in lignin biosynthesis.
Modulation of cortical inputs from tooth pulp by electrical stimulation of adjacent gingiva

Abstract Corticopetal inputs from tooth pulp having analgesic sensitivity are characterized and experiments are described which test whether electrical stimulation of adjacent gingiva attenuates these analgesic-sensitive cortical evoked responses.
Two-dimensional scaffolds for the parallel alignment of rod-shaped conjugated molecules.

Described is a method for creating two-dimensional, ordered arrays of linear, conjugated organic molecules on polyimide scaffolds. Key to the design was the enforcement of consecutive 90° twist angles along the polyimide backbone. Rod molecules that are templated by such scaffolds are held parallel and in the same plane and have optical properties that are similar to those of monomeric analogues. As supporting evidence for the structures of the polymers, a series of model compounds were synthesized and characterized by X-ray crystallography. The polymeric materials are soluble and have been characterized by 1H NMR, 13C NMR, MALDI-TOF, and UV−vis spectroscopy.
An analytic solution for an algebraic matrix Riccati equation

A procedure is given whereby an analytic solution may sometimes be found for a matrix algebraic equation, such as occurs in deterministic and stochastic optimization problems.
Modified log-wake-law for smooth rectangular open channel flow

Smooth rectangular open channel flow is a benchmark for studying river hydraulics and sediment transport. Such a flow is more complicated than the classic boundary layer flow at least in two ways: (i) the maximum velocity occurs below the water surface, which is called the velocity-dip-phenomenon and (ii) the velocity distribution is affected not only by the channel bottom but also by the side-walls and the free surface. This fundamental flow is approximated herein by three hypotheses: (i) the velocity-dip-position shifts exponentially from the water surface to half flow depth as the width–depth ratio decreases from infinity to zero; (ii) the conventional wake-law for the centreline velocity distribution results from boundary shear stresses including the bottom, side-walls, and water surface in terms of secondary currents; and (iii) the cross-sectional velocity distribution is described by Guo and Julien's modified log-wake-law. These hypotheses are well supported by flume data.
Global Speleothem Oxygen Isotope Measurements Since the Last Glacial Maximum

This synthesis of thirty-six sites (sixty cores with over 27 000 measurements) located around the world facilitates scientific research on the climate of the last 21 000 years ago obtained from oxygen isotope ( <path id="x1D6FF" d="M494 514l-10 -15q-56 76 -106.5 117t-110.5 41q-45 0 -45 -30q0 -28 109 -152q59 -68 86 -118.5t27 -107.5q0 -62 -29.5 -119.5t-86.5 -96.5q-64 -45 -138 -45q-76 0 -121.5 53t-45.5 136q0 74 40.5 135t98.5 95q43 26 87 42q-40 59 -57.5 92t-17.5 62q0 46 39 77.5 t90 31.5q54 0 97.5 -35.5t65 -78.5t28.5 -84zM359 234q0 84 -90 191q-47 -17 -74 -47q-81 -89 -81 -200q0 -71 32.5 -109.5t72.5 -38.5q47 0 80 33t46.5 77.5t13.5 93.5z" /> <path id="x38" d="M249 635q70 0 116 -43t46 -105q0 -46 -28 -80q-22 -25 -80 -64q62 -35 97 -75t35 -99q0 -81 -63 -131t-135 -50q-83 0 -137.5 45.5t-54.5 123.5q0 52 45 95q29 28 89 64q-109 62 -109 155q0 66 50.5 115t128.5 49zM238 603q-42 0 -67.5 -31t-25.5 -72q0 -50 32.5 -79.5 t98.5 -62.5q61 48 61 124q0 59 -29.5 90t-69.5 31zM248 20q46 0 76.5 33.5t30.5 89.5q0 50 -39 85.5t-110 71.5q-81 -54 -81 -137q0 -67 35.5 -105t87.5 -38z" /> or delta-O-18) measurements. Oxygen isotopes in speleothem calcite record the influence of ambient temperature and the isotopic composition of the source water, the latter providing evidence of hydrologic variability and change. Compared to paleoclimate proxies from sedimentary archives, the age uncertainty is unusually small, around +/−100 years for the last 21 000-year interval. Using data contributed to the World Data Center (WDC) for Paleoclimatology, we have created consistently formatted data files for individual sites as well as composite dataset of annual to millennial resolution. These individual files also contain the chronology information about the sites. The data are useful in understanding hydrologic variability at local and regional scales, such as the Asian summer monsoon and the Intertropical Convergence Zone (as discussed in the underlying source publications), and should also be useful in understanding large-scale aspects of hydrologic change since the Last Glacial Maximum (LGM).
Intensity and Polarization of the Radiation Emerging from an Optically Thick Rayleigh Atmosphere

The intensity and degree of polarization of the radiation diffusely transmitted and reflected by a plane-parallel, homogeneous Rayleigh atmosphere were computed for scattering optical thicknesses τ1 from 1.0 to 10.0. The results show that the distribution of the intensity of the radiation diffusely reflected by an atmosphere of τ1 = 10.0 is similar to that reflected by an atmosphere of infinite optical depth. The distributions of the degree of polarization are identical for τ1 = 10.0 and ∞ when the sun is at the zenith; otherwise, they are significantly different. Except for the magnitude of the intensity which decreases with increasing solar zenith distance, the distributions of the intensity and polarization of the diffusely transmitted radiation are independent of the sun’s position when τ1 ~ 10.0 or greater. An interesting feature displayed by the polarization of the transmitted radiation for 1.0≤τ1≤2.0 is the simultaneous appearance of four neutral points at low elevations of the sun. For higher values of τ1, neutral points are nonexistent.
Electron-stimulated-desorption ion angular distributions of negative ions.

Electron bombardment of molecules adsorbed on surfaces can lead to the desorption of positive ions as well as ground state and excited neutral species. In addition, in many systems desorption of negative ions has been observed [1]. The measurement of the angular distributions of the desorbing species (ESDIAD: electron stimulated desorption ion angular distributions) can yield important information about the bonding geometry of species adsorbed on surfaces because the initial direction of desorption has been found to be related to the bond vector directions [2].
Measuring productive computational work

The measurement of computational work in computer systems traditionally relied heavily on indicators of hardware. Unfortunately, these indicators have a low correlation to the user's perception of useful work. This paper defines computations in terms of fundamental bit logical manipulations and shows the user's “useful computational work” can be quantized from a job specification in FORTRAN source statements. The method can be automated yielding a specific quantity of work for a given method FORTRAN program with specified data. The resulting measure of work can be used to obtain ranges of computational power for any system on which the benchmarks are executed.
Lymphocyte subpopulations of blood and alveolar lavage in blastomycosis.

Patients with blastomycosis were found to have differing lymphocyte populations depending on the extent of disease manifestations and whether or not therapy had been started. Patients with recovering pulmonary blastomycosis who had been receiving antifungal treatment for at least four weeks had lymphocyte subpopulations no different from control donors. Patients with treated extrapulmonary blastomycosis had similar T helper (T H ) to T suppressor (T s ) ratios compared to recovering pulmonary patients and control subjects; this ratio gives a false impression because extrapulmonary blastomycosis patients had a reduced absolute number of lymphocytes with either marker. In bronchoalveolar lavage fluid, pulmonary blastomycosis patients who were clinically improved while receiving antifungal therapy had fewer T H cells and a greater number of lymphocytes with the T s marker than did control subjects. Patients with pulmonary blastomycosis prior to therapy had a smaller ratio than the other groups in peripheral blood primarily due to a reduction in the circulating T H fraction in both absolute numbers of cells and in the percentage of total T lymphocytes. Pulmonary blastomycosis patients re-evaluated after at least four weeks of antifungal therapy had ratios that were similar to normal persons. This increase in T H lymphocytes corresponded to clinical improvement and in a temporal correlation to that described for the development of specific immunity in this illness.
Localized surface plasmons and hot electrons

Abstract The ability of plasmonic devices to generate hot electrons has the potential to move chemical manufacturing outdoors by harnessing photon energy and converting it to useful chemical energy. By using localized surface plasmons to generate hot carriers in noble metal nanostructures, visible light can produce energetic electrons (or holes) which drive chemical reactions or create a light-induced photocurrent. Within this Perspective, we look into recent theory of plasmonic hot electron generation and how the underlying nanoparticle structure influences both the number and energy of the hot carriers produced. Applications in photodiodes and photocatalysis are highlighted to demonstrate potential device opportunities for plasmon-generated hot electrons. Super-resolution imaging studies, in which the location of hot carrier production in hybrid plasmonic-semiconductor devices is spatially localized to
A wind-profile index for canopy flow

Canopy wind profiles can often be represented by an exponential function. The associated attenuation index,a, is found to be proportional to [(Flexibility)(Leaf Area)(Density)]1/3. Leastsquare values of the index have been calculated for wind profiles in about a dozen natural and artificial canopies which included oats, wheat, corn, rice, sunflowers, larch trees, citrus trees, Xmas trees, plastic strips, wooden pegs and bushel baskets. It is found that canopy flow is a function of canopy density, element flexibility, and height and that the behaviour of artificial canopy elements is compatible with that of natural vegetation. The same calculations also show that the attenuation coefficient: (a) is not a universal constant, (b) is however, rather limited in range (∼-0.3 to 3.0), (c) varies with stage of growth, and (d) increases as density and flexibility increase. A compilation ofa-values for several canopies reveals that lowa-values correspond to sparsely arrayed rigid elements while higha-values correspond to densely arrayed and flexible elements. Finally, lowa-values appear to be relatively independent of wind speed, while higha-values tend to increase as wind speeds increase.
Extraction of Stress Intensity Factors for the Simulation of 3-D Crack Growth with the Generalized Finite Element Method

Two methods for the extraction of Stress Intensity Factors (SIFs) from three-dimensional (3-D)problems are presented: the Contour Integral Method and the Cutoff Function Method. The formula-tions are tailored for the Generalized Finite ElementMethod andmixed-mode 3-D propagating cracks.The case of crack faces loaded by prescribed tractions is also considered. Another contribution of thispaper is a procedure to control the noise of extracted SIFs based on theMoving Least SquaresMethod.The proposed approach provides a continuous and smooth approximation of 3-D SIF functions foreach fracture mode. Numerical experiments demonstrating the accuracy and robustness of the pro-posed methodology are presented. They include 3-D mixed-mode fatigue crack growth simulationsand the case of a pressurized crack.
Invited review article: The Chandra X-ray Observatory.

The Chandra X-ray Observatory is an orbiting x-ray telescope facility. It is one of the National Aeronautics and Space Administration's four “Great Observatories” that collectively have carried out astronomical observations covering the infrared through gamma-ray portion of the electromagnetic spectrum. Chandra is used by astronomers world-wide to acquire imaging and spectroscopic data over a nominal 0.1–10 keV (124–1.24 A) range. We describe the three major parts of the observatory: the telescope, the spacecraft systems, and the science instruments. This article will emphasize features of the design and development driven by some of the experimental considerations unique to x-ray astronomy. We will update the on-orbit performance and present examples of the scientific highlights.
An inversion of gravity and topography for mantle and crustal structure on Mars

Analysis of the gravity and topography of Mars presently provides our primary quantitative constraints on the internal structure of Mars. We present an inversion of the long-wavelength (harmonic degree ≤ 10) gravity and topography of Mars for lateral variations of mantle temperature and crustal thickness. Our formulation incorporates both viscous mantle flow (which most prior studies have neglected) and isostatically compensated density anomalies in the crust and lithosphere. Our nominal model has a 150-km-thick high-viscosity surface layer over an isoviscous mantle, with a core radius of 1840 km. It predicts lateral temperature variations of up to a few hundred degrees Kelvin relative to the mean mantle temperature, with high temperature under Tharsis and to a lesser extent under Elysium and cool temperatures elsewhere. Surprisingly, the model predicts crustal thinning beneath Tharsis. If correct, this implies that thinning of the crust by mantle shear stresses dominates over thickening of the crust by volcanism. The major impact basins (Hellas, Argyre, Isidis, Chryse, and Utopia) are regions of crustal thinning, as expected. Utopia is also predicted to be a region of hot mantle, which is hard to reconcile with the surface geology. An alternative model for Utopia treats it as a mascon basin. The Utopia gravity anomaly is consistent with the presence of a 1.2 to 1.6 km thick layer of uncompensated basalt, in good agreement with geologic arguments about the amount of volcanic fill in this area. The mantle thermal structure is the dominant contributor to the observed geoid in our inversion. The mantle also dominates the topography at the longest wavelengths, but shorter wavelengths (harmonic degrees ≥4) are dominated by the crustal structure. Because of the uncertainty about the appropriate numerical values for some of the model's input parameters, we have examined the sensitivity of the model results to the planetary structural model (core radius and core and mantle densities), the mantle's viscosity stratification, and the mean crustal thickness. The model results are insensitive to the specific thickness or viscosity contrast of the high-viscosity surface layer and to the mean crustal thickness in the range 25 to 100 km. Models with a large core radius or with an upper mantle low-viscosity zone require implausibly large lateral variations in mantle temperature.
Volume changes accompanying collagen denaturation

A dilatometric technique is employed to measure the volume changes occurring on denaturation of collagen solutions and tendons. Partial specific volumes of tropocollagen are calculated to be 0.686 ml./g. in water and 0.689 ml/g in 0.1M citrate buffer. From data on non-aqueous solutions, it is estimated that most of the volume change arises from changes in polymer configuration rather than from changes in solvation.
FLUORESCENCE LINE NARROWING SPECTROSCOPY OF Zn PORPHYRINS

Fluorescence line narrowing (FLN) spectroscopy was used to study the vibrational features of Zn porphyrins, including Zn octaethylporphine, Zn mesoporphyrin, Zn deuteroporphyrin and Zn coproporphyrin, and the interaction of these porphyrins with their solvent matrices. A number of ground-state vibrational levels were identified for each of the Zn porphyrins. Six of these levels persistent throughout almost all spectra were analyzed in terms ofcontributions of specific internal vibrational modes of the porphyrins. A number of other vibrational levels were identified as characteristic of the peripheral substituents of Zn porphyrin. Phonon wing contribution in the FLN spectra increased with increased polarity of the solvent matrix, and the Stokes shift calculated from the conventional spectra was correlated with the strength of phonon coupling. Specific vibrational modes were found to couple differently with the solvent and to have different phonon wings. The conventional and energy-selected spectra of Zn coproporphyrin in 5 M guanidine HCI suggest that guanidine ligates to the Zn atom.
A routine method for the determination of digoxin in urine by radioimmunoassay

Abstract We describe a radioimmunoassay for the routine determination of digoxin in urine employing readily available commercial reagents. The standard curve was found to exhibit very good linearity represented by a composite correlation coefficient of 0.9993 and a standard error of estimate which was less than 1% of the digoxin concentration range of interest. Between-assay precision was excellent as reflected by the coefficient of variation (CV) which averaged 5.29%. Studies assessing the recovery of the present method showed satisfactory results of 106% at a low level of digoxin excretion and 102% at a higher excretion level. Our laboratory carried out a study of digoxin bioavailability in which a standard digoxin dose of 500 μg was given to 16 volunteers and the present radioimmunoassay method was employed to measure digoxin excretion. An amount equal to 33.4 ± 6% of the drug given was eliminated 48 h following digoxin dosing.
Vertical spillovers, market concentration, union coverage, and wages

This paper outlines a model that tests for the presence of spillover effects of union coverage across industry boundaries on wages and union coverage in vertically related industries. There is some evidence of spillover effects from buying industries to the wages of nonunion workers and of such effects on the degree of union coverage from both buying and supplying industries.
Flexural Properties of Reinforced Polyester Concrete Made with Recycled PET

The flexural strength of steel-reinforced polymer concrete (PC) beams us ing unsaturated polyester resins based on recycled poly(ethylene terephthalate), PET, is reported in this paper. Investigation included mode of failure, moment-curvature response, variation of neutral axis depth with moments and the effect of tensile and compression steel reinforcement on the strength and ductility of the beams. This evaluation is not only important from the standpoint that resins based on recycled PET were used, but also because very few investigations have been done in this area with steel-reinforced PC using virgin resins.
Studies on the nature of chemical signals in scent marks and urine ofSaguinus fuscicollis (Callitricidae, primates)

The circumgenital scent marks ofSaguinus fuscicollis are mixtures of skin gland secretions, urine, and perhaps vaginal discharge. One of their ingredients, urine, is readily investigated by conspecifics. Female tamarins are able to utilize urine to discriminate between the sexes, but it appears that urine, unlike the scent marks, offers no clues for individual discrimination. Moreover, urine is less attractive to conspecifics than complete scent marks, which signal sex and individuality. The sexual identity of marks is recognized even if the tamarins are prevented from contacting the material directly and seems to be retained in a mixture of scent from both sexes.
Design Features of New 16,500-KW Gas Turbines for Power Generation

The combustion gas turbine has come to be an accepted means of power generation in the world today and, as has been the case with all power generation equipment, there is a demand for ever increasing sizes. To meet this demand, late in 1954 the author’s Company embarked on the design of a unit to be rated approximately 15,000 kw.Copyright © 1957 by ASME
Terahertz Imaging for Anti-personnel Mine Detection

The detection of buried anti-personnel mines has presented problems for current mine detection methods, such as ground penetrating radar. Terahertz (THz) radiation provides the ability to obtain higher resolution images as well as the ability to obtain spectroscopic information on the explosives in and around the buried mines. Propagation of THz in granular media is studied using techniques adapted from material science for foams and ceramics and adapted to sand and soil. We then give early results of 2-D reflection imaging of objects buried in sand. A terahertz time domain reflection system with a GaAs photoconductive emitter, a ZnTe electro-optic detector, and a rapid delay scanning mechanism was used to produce and collect the transmitted THz signal.
Outsourcing, Self‐Service and the Telemobility of Work

This essay offers labor's advocates and ethnographers a conceptual and historical framework for outsourcing. Jobs being moved abroad are less the focus than work being transferred from the processes of production and distribution into the realms of consumption and everyday life. Call centers in India have attracted tremendous attention recently in the U.S. and have become an iconic site of outsourced jobs. The cultural politics animating these reactions are discussed, and comparisons are drawn between reactions to call centers and initial encounters with ATMs, in order to elaborate how we have approached outsourcing and automation as problems for labor. Both outsourcing and automation are analyzed in terms of the mobility of work, distinguishable from the mobility of labor and capital. Call center calls and ATM (automated teller machines) transactions are described as genres of outsourced work and as instances of customers working to serve themselves. Finally, self-service is conceptualized as collaborative, and some political implications of pursuing solidarity in call centers and at ATMs are noted. One upshot of this framework is that customers serving themselves emerge, alongside discounted labor and the newly unemployed, as another key group of outsourced workers who demand our ethnographic attention.
Diurnal fluctuations in soil water potential

Field data collected from thermocouple psychrometers operated under the control of an automatic switching network and scanning system are presented. A numeric interpolation procedure is described which permits corrections for varying sensitivity of the psychrometers over a wide range of temperatures and water potentials. Psychrometers installed in ceramic cups buried in soil permeated by an active root system showed a significant day-to-night fluctuation in water potential coincident with the evaporative demands of the plant.
Simulations of Bioprosthetic Heart Valve Dynamics Using a Sharp Interface Method

Bioprosthetic heart valves are valve replacements constructed from animal tissue. They are deformable and offer similar mechanical properties to their native counterpart. While tearing of these valves is frequently observed, it is still not fully understood, but may be the result of high induced bending and shear stresses in the valve leaflets[1].© 2007 ASME
Pulmonary embolism demonstrated by computerized tomography

Abstract We describe a case of pulmonary embolism diagnosed by computerized tomography. Scanning by CT in pulmonary embolism shows promise as an alternative to pulmonary angiography for definitive diagnosis. It is especially valuable for patients who are considered as high risk for pulmonary angiography and for serial follow-up of pulmonary embolism.