cssi/SciSciGPT-SciSciNet huggingface dataset:
Fast-switching dual energy cone beam computed tomography using the on-board imager of a commercial linear accelerator.

To evaluate fast-kV switching (FS) dual energy (DE) cone beam computed tomography (CBCT) using the on-board imager (OBI) of a commercial linear accelerator to produce virtual monoenergetic (VM) and relative electron density (RED) images. Using an polynomial attenuation mapping model, CBCT phantom projections obtained at 80 and 140 kVp with FS imaging, were decomposed into equivalent thicknesses of aluminum (Al) and polymethyl methacrylate (PMMA). All projections were obtained with the titanium foil and bowtie filter in place. Basis material projections were then recombined to create VM images by using the linear attenuation coefficients at the specified energy for each material. Similarly, RED images were produced by replacing the linear attenuation values of Al and PMMA by their respective RED values in the projection space. VM and RED images were reconstructed using Feldkamp-Davis-Kress (FDK) and an iterative algorithm (iCBCT, Varian Medical Systems). Hounsfield units (HU), contrast-to-noise ratio (CNR) and RED values were compared against known values. The results after VM-CBCT production showed good material decomposition and consistent HUVM values, with measured root mean square errors (RMSE) from theoretical values, after FDK reconstruction, of 20.5, 5.7, 12.8 and 21.7 HU for 50, 80, 100 and 150 keV, respectively. The largest CNR improvements, when compared to polychromatic images, were observed for the 50 keV VM images. Image noise was reduced up to 28% in the VM-CBCT images after iterative image reconstruction. RED values measured for our method resulted in a mean percentage error of 0.0% ± 1.8%. This study describes a method to generate VM-CBCT and RED images using FS-DE scans obtained using the OBI of a linac, including the effects of the bowtie filter. The creation of VM and RED images increases the dynamic range of CBCT images, and provides additional data that may be used for adaptive radiotherapy, and on table verification for radiotherapy treatments.
Verbal prefixes in Old Northumbrian: Evidence from the Lindisfarne glosses

Abstract In late Old English dialects, adverbial elements are frequently morphologically ambiguous (independent words, clitics, verbal prefixes, etc.), and an important facet of the proper treatment of these items is the quality of source-data in different texts. This paper examines the usage of three adverbial/prepositional elements in the Northumbrian Lindisfarne Glosses: eft ‘again, after’, ymb ‘around’, and ofer ‘over’. Skeat (1871–87), whose transcription of the original manuscript is the primary reference for research on the Glosses, frequently transcribes these items as prefixes, alongside other OE prefixes like ge-, a-, for-, and be-. However, Skeat also deviates from this pattern in many cases, leaving their proper analysis uncertain. Nevertheless, various works (e.g., Cook 1894; Bosworth 2011), have indeed taken these items to be prefixes. I follow Fernandez-Cuesta (2016) in revisiting the original Lindisfarne manuscript to determine the correct treatment of these items, concluding that eft and ofer should not be analyzed as prefixes in the manuscript, while ymb should have prefix status.
A Fast Charge/Discharge and Wide-Temperature Battery with a Germanium Oxide Layer on a Ti3C2 MXene Matrix as Anode

A rapid charge/discharge secondary battery is critical in portable electronic devices and electric vehicles. Germanium, due to the metallic property and facile alloying reaction with lithium, displays great potential in fast charge/discharge batteries in contrast to other intercalation batteries. In order to accommodate the over 300% volume change, a 2D hybrid composite electrode consisting of a homogeneous, amorphous GeOx(x=1.57) layer bonded on Ti3C2 MXenes was successfully developed via an industry available method. The expanded interlayer space inside the MXene matrix accommodates the restricted isotropic expansion from the stress-released, ultrathin GeOx layer. Owing to the improved e-/Li+ conductivity from both metallic reduced Ge and MXene, the battery showed an excellent charge/discharge performance as fast as 3 min (20.0 C). A high-capacity retention of ∼1048.1 mAh/g along with a Coulombic efficiency (CE) of 99.8% at 0.5 C after 500 cycles was achieved. Under 1.0 C, the capacity was still up to 929.6 mAh/g with a CE of 99.6% (<0.02% capacity decay per cycle) after ultralong (1000) cycling. An almost doubled capacity of 671.6 mAh/g compared to graphite (372 mAh/g at 0.1 C) under 5.0 C and a capacity of 300.5 mAh/g under 10.0 C after 1000 cycles were respectively received. Under cold conditions, due to the low interface energy barrier, an efficient alloying reaction happens which prevents the Li plating on the electrode surface. High capacities of 631.6, 333.9, and 841.7 mAh/g under -20, -40, and 60 °C after 100 cycles demonstrate a wide temperature tolerance of the battery. In addition, a full-cell battery paired with LiNi0.8Mn0.1Co0.1O2 (NMC811) displayed a high capacity of 536.8 mAh/g after 200 cycles. A high capacity retention of a full pouch cell after 50 cycles was also obtained. The superhigh rate capability along with long cycling, wide temperature range, scalable production, and relatively low cost of this hybrid composite display promising potential in specific energy storage applications.
3D Printing of Complex, High-Performance Millimeter-Wave Components

We report on a complete fabrication process to realize complex, high-performance microwave components using digital-light-processing (DLP) 3D printing. Our approach addresses numerous challenges of successful component realization, including: metalization of acrylate-based polymers, defect reduction in printing, increased precision through off-axis printing of waveguide channels and re-design of precision internal structures for self-supporting in the build process. The results of our approach have produced complex microwave components with performance comparable to commercial, multi-part CNC machined components.
Preliminary Analysis of the Induced Structural Radioactivity Inventory of the Base-Case Aqueous Accelerator Transmutation of Waste Reactor Concept

The purpose of the Los Alamos National Laboratory Accelerator Transmutation of (Nuclear) Waste (ATW) project is the substantial reduction in volume of long-lived high-level radioactive waste of the US in a safe and energy-efficient manner. An evaluation of the ATW concept has four aspects: material balance, energy balance, performance, and cost. An evaluation of the material balance compares the amount of long-lived high-level waste transmuted with the amount and type, of waste created in the process. One component of the material balance is the activation of structural materials over the lifetime of the transmutation reactor. A preliminary radioactivity and radioactive mass balance analysis has been performed on four structure regions of the reaction chamber: the tungsten target, the lead annulus, six tubing materials carrying the actinide slurry, and five reaction vessel structural materials. The amount of radioactive material remaining after a 100-yr cooling period for the base-case ATW was found to be 338 kg of radionuclides. The bulk of this material (313 kg) was generated in the zirconium-niobium (Zr-Nb) actinide tubing material. Replacement of the Zr-Nb tubing material with one of the alternative tubing materials analyzed would significantly reduce the short- and long-term radioactive mass produced. The alternative vessel materialmore » Al-6061 alloys, Tenelon, HT-9, and 2 1/4 Cr-1 Mo and the alternative actinide tubing materials Al-6061 alloy, carbon-carbon matrix, silicon carbide, and Ti-6 Al-4 V qualify for shallow land burial. Alternative disposal options for the base-case structural material Type 304L stainless steel and the actinide tubing material Zr-Nb will need to be considered as neither qualifies for shallow land burial.« less
New Kids on the Block: The Effect of Generation X Directors on Corporate Performance

Generation X directors are slowly replacing Baby Boomers on U.S. corporate boards and will eventually dominate corporate boardrooms in the U.S. and around the world. We provide the first robust evidence of a significantly positive effect of Generation X directors on corporate performance. The positive effect is not driven by other director attributes such as age, sex, ethnicity, or professional expertise, and is robust to endogeneity checks using instrumental variables. Part of the improvement in firm performance can be attributed to the commitment of Generation X directors to corporate social responsibility and to the inclusion of women on corporate boards.
Contrast-Dependence of Temporal Frequency Tuning in Mouse V1

The perception of speed is influenced by visual contrast. In primary visual cortex (V1), an early stage in the visual perception pathway, the neural tuning to speed is directly related to the neural tuning to temporal frequency of stimulus changes. The influence of contrast on speed perception can be caused by the joint dependency of neural responses in V1 on temporal frequency and contrast. Here, we investigated how tuning to contrast and temporal frequency in V1 of anesthetized mice are related. We found that temporal frequency tuning is contrast-dependent. V1 was more responsive at lower temporal frequencies than the dLGN, consistent with previous work at high contrast. The temporal frequency tuning moves toward higher temporal frequencies with increasing contrast. The low half-maximum temporal frequency does not change with contrast. The Heeger divisive normalization equation provides a good fit to many response characteristics in V1, but does not fit the dependency of temporal frequency and contrast with set of parameters for all temporal frequencies. Different mechanisms for normalization in the visual cortex may predict different relationships between temporal frequency and contrast non-linearity. Our data could help to make a model selection.
Crack initiation and growth in additively printed ABS: Effect of print architecture studied using DIC

Abstract Acrylonitrile Butadiene Styrene or ABS is a popular and inexpensive isotropic, amorphous thermoplastic widely used for Additive Manufacturing (AM) of engineering parts. An AM process called Fused Filament Fabrication (FFF) involving layer-by-layer deposition of melted thermoplastic wire through a heated nozzle along predetermined paths is common for printing thermoplastics such as ABS. Individual layers printed during AM can be configured differently and could introduce anisotropy into the part due to weaker planes between individual beads even when the feedstock is isotropic. This research examines the tensile and fracture behaviors of three in-plane print architectures, namely [0°/90°]n, [45°/-45°]n and [0°/45°/90°/-45°]n orientations. The full-field measurement of local in-plane displacements are performed optically using Digital Image Correlation (DIC) method up to crack initiation and during crack growth in quasi-statically loaded 3-point bend edge-notched specimens. A simple method of analyzing DIC data by transferring it to a corresponding finite element model for computing the J-integral and then partitioning it into individual stress intensity factors is developed. Even though the printed architectures show macroscopic elastic isotropy, significant differences in the failure strain, crack initiation and growth parameters, and failure modes among the three architectures are observed. These differences are explained using tests performed on comparable unidirectional prints. The results suggest that [0°/45°/90°/-45°]n are preferable to the other two more common configurations for a relatively graceful failure behavior and higher resistance to crack growth, suggesting that better fracture performance could be achieved by manipulating print architecture.
Towards Model-Centric Security for IoT Systems

In this paper, we make a case for a novel model-centric security approach to the IoT application systems. We thus depart from the popular device-centric and data-centric schemes. Our proposal is based on the premise that the trained model, rather than the fine-grained input and output data streams, plays the pivotal role in many IoT application systems. We thus seek to obfuscate the model directly, but not the individual data items or sensory data streams. We present our initial design of sampling-based model obfuscation. Both evaluations and analysis have partially confirmed our design to date.
A Spectral Integral Equation Solution of the Gross-Pitaevskii Equation

The Gross-Pitaevskii equation (GPE), that describes the wave function of a number of coherent Bose particles contained in a trap, contains the cube of the normalized wave function, times a factor proportional to the number of coherent atoms. The square of the wave function, times the above mentioned factor, is defined as the Hartree potential. A method implemented here for the numerical solution of the GPE consists in obtaining the Hartree potential iteratively, starting with the Thomas Fermi approximation to this potential. The energy eigenvalues and the corresponding wave functions for each successive potential are obtained by a spectral method described previously. After approximately 35 iterations a stability of eight significant figures for the energy eigenvalues is obtained. This method has the advantage of being physically intuitive, and could be extended to the calculation of a shell-model potential in nuclear physics, once the Pauli exclusion principle is allowed for.
A rapid thioacidolysis method for biomass lignin composition and tricin analysis.

Biomass composition varies from plant to plant and greatly affects biomass utilization. Lignin is a heterogeneous phenolic polymer derived mainly from p-coumaryl, coniferyl, and sinapyl alcohols and makes up to 10–25% of lignocellulosic biomass. Recently, tricin, an O-methylated flavone, was identified as a lignin monomer in many grass species. Tricin may function as a nucleation site for lignification and is advocated as a novel target for lignin engineering to reduce lignin content and improve biomass digestibility in grasses. Thioacidolysis is an analytical method that can be adapted to analyze both lignin monomeric composition and tricin content in the lignin polymer. However, the original thioacidolysis procedure is complex, laborious, and time consuming, making it difficult to be adopted for large-scale screening in biomass research. In this study, a modified, rapid higher throughput thioacidolysis method was developed. In combination with gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–mass spectrometry (LC–MS), the modified thioacidolysis method can be used to simultaneously characterize the lignin composition and tricin content using 2–5 mg of dry samples. The modified method eliminates the solvent extraction and drastically improves the throughput; 80 samples can be processed in one day per person. Our results indicate that there is no significant difference in the determination of lignin S/G ratio and tricin content between the original and modified methods. A modified thioacidolysis protocol was established. The results demonstrate that the modified method can be used for rapid, high-throughput, and reliable lignin composition and tricin content analyses for screening transgenic plants for cell wall modifications or in large-scale genome-wide association studies (GWAS).
Training deep-learning segmentation models from severely limited data.

Purpose To enable generation of high-quality deep learning segmentation models from severely limited contoured cases (e.g., ~10 cases). Methods Thirty head and neck computed tomography (CT) scans with well-defined contours were deformably registered to 200 CT scans of the same anatomic site without contours. Acquired deformation vector fields were used to train a principal component analysis (PCA) model for each of the 30 contoured CT scans by capturing the mean deformation and most prominent variations. Each PCA model can produce an infinite number of synthetic CT scans and corresponding contours by applying random deformations. We used 300, 600, 1000, and 2000 synthetic CT scans and contours generated from one PCA model to train V-Net, a 3D convolutional neural network architecture, to segment parotid and submandibular glands. We repeated the training using same numbers of training cases generated from 7, 10, 20, and 30 PCA models, with the data distributed evenly between each PCA model. Performance of the segmentation models was evaluated with Dice similarity coefficients between auto-generated contours and physician-drawn contours on 162 test CT scans for parotid glands and another 21 test CT scans for submandibular glands. Results Dice values varied with the number of synthetic CT scans and the number of PCA models used to train the network. By using 2000 synthetic CT scans generated from 10 PCA models, we achieved Dice values of 82.8% ± 6.8% for right parotid, 82.0% ± 6.9% for left parotid, and 74.2% ± 6.8% for submandibular glands. These results are comparable with those obtained from state-of-the-art auto-contouring approaches, including a deep learning network trained from more than 1000 contoured patients and a multi-atlas algorithm from 12 well-contoured atlases. Improvement was marginal when >10 PCA models or >2000 synthetic CT scans were used. Conclusions We demonstrated an effective data augmentation approach to train high-quality deep learning segmentation models from a limited number of well-contoured patient cases.
Mechanical Ventilation and Coronavirus Disease 2019: A Case-Control Analysis of Clinical Characteristics, Lung Mechanics, and Mortality

Objectives: To investigate the differences in clinical course, ventilator mechanics, and outcomes of patients with coronavirus disease 2019 secondary to acute respiratory distress syndrome infection compared with a historical cohort of acute respiratory distress syndrome. Design: Comparative case-control study. Setting: Multicenter, comprehensive tertiary healthcare facility in Detroit, MI. Patients/Subjects: Adult patients hospitalized with coronavirus disease 2019 secondary to acute respiratory distress syndrome infection were compared with patients hospitalized with acute respiratory distress syndrome prior to the coronavirus disease 2019 pandemic (control). Interventions: None. MEASUREMENTS AND Main Results: We included 384 patients in the analysis. Inpatient mortality was significantly higher in patients with coronavirus disease 2019 secondary to acute respiratory distress syndrome infection compared with controls (64% vs 49%;p = 0.007). Despite both groups demonstrating similar ventilatory function and Sequential Organ Failure Assessment score on day 1 of intubation, with similar lung compliance throughout the study period, patients with coronavirus disease 2019 secondary to acute respiratory distress syndrome infection demonstrated progressive hypoxia compared with controls across the study period. Similarly, higher positive end-expiratory pressure levels and increased use of paralytics were observed in the patients with coronavirus disease 2019 secondary to acute respiratory distress syndrome infection group. On univariate analysis of the entire cohort, significant risk factors for inpatient mortality included coronavirus disease 2019 infection (p = 0.007), older age (p < 0.001), high Sequential Organ Failure Assessment score (p = 0.003), vasopressor use (p = 0.039), paralytic use (p < 0.001), higher positive end-expiratory pressure levels on day 3 (p = 0.027) and day 7 (p < 0.001), in addition to acute respiratory distress syndrome severity on both days 3 (p = 0.008) and 7 (p < 0.001). Multivariate analysis identified coronavirus disease 2019 infection (odds ratio, 1.939;p = 0.021), older age (odds ratio, 1.042;p < 0.001), paralytic use (odds ratio, 3.366;p < 0.001), and higher Sequential Organ Failure Assessment score (odds ratio, 1.152;p = 0.027) as significant predictors of mortality across the entire cohort. Conclusions: Patients with coronavirus disease 2019 secondary to acute respiratory distress syndrome infection demonstrated higher mortality compared with control patients hospitalized with acute respiratory distress syndrome prior to the pandemic, with progressive hypoxia throughout the study period, despite similar lung mechanics and initial Sequential Organ Failure Assessment score. Coronavirus disease 2019 infection, older age, paralytic use, and higher Sequential Organ Failure Assessment scores were independent risk factors for 28-day mortality across the entire cohort.
Optimization: Using Models, Validating Models, Solutions, Answers

This chapter guides the reader into the field of mathematical optimization, distinguishes optimization from simulation, and introduces the key objects used in optimization models. It sketches how simple linear programming (LP) problems may be solved graphically. The chapter contains a survey of real-world problems and finally a review of the history of optimization. Those readers who want to use the optimization software attached to this book will find sufficient information in this chapter to do so. Readers less interested in implementation issues or already familiar with the use of commercial software may of course skip those parts.
"Could we have predicted this?" The association of a future mental health need in young people with a non-specific complaint and frequent emergency department visits.

Objective Mental health emergencies among young people are increasing. There is growing pressure for emergency departments to screen patients for mental health needs even when it is not their chief complaint. We hypothesized that young people with an initial non-specific condition and emergency department (ED) revisits have increased mental health needs. Methods Retrospective, observational study of the California Office of Statewide Health Planning and Development Emergency Department Discharge Dataset (2010-2014) of young people (11-24 years) with an index visit for International Classification of Diseases, Ninth Revision diagnostic codes of "Symptoms, signs, and ill-defined conditions" (Non-Specific); "Diseases of the respiratory system" (Respiratory) and "Unintentional injury" (Trauma) who were discharged from a California ED. Patients were excluded if they had a prior mental health visit, chronic disease, or were pregnant. ED visit frequency was counted over 12 months. Regression models were created to analyze characteristics associated with a mental health visit. Results Patients in the Non-Specific category compared to the Respiratory category had 1.2 times the odds of a future mental health visit (OR 1.20; 95% CI 1.17-1.24). Patients with ≥1 ED revisit, regardless of diagnostic category, had 1.3 times the odds of a future mental health visit. Patients with both a Non-Specific index visit and 1, 2, and 3 or more revisits with non-specific diagnoses had increasing odds of a mental health visit (OR 1.38; 95% CI 1.29-1.47; OR 1.70; 95% CI 1.46-1.98; OR 2.20; 95% CI 1.70-2.87, respectively.). Conclusions Young people who go to the ED for non-specific conditions and revisits may benefit from targeted ED mental health screening.
Beer's Law

Beer's law is the fundamental law of quantitative absorption spectroscopy because it relates the absorbance to the product of the concentration of each analyte and the pathlength of the cell. In this article, the theoretical requirements for Beer's law to be obeyed are given; these include the need for a collimated beam of monochromatic radiation and the need for a dilute homogeneous solution of the analyte. In practice, these requirements can be relaxed but in order for Beer's law to be obeyed, interaction between the analyte molecules that can cause the absorptivity to change as a function of concentration must be constant. The optimum condition for quantitative spectroscopy is found when the transmittance is equal to 1/e. Baseline correction is sometimes needed to obtain the optimum result, but this may at times be a subjective operation. Instrumental effects on Beer's law linearity are discussed in some detail. For measurements of concentrated solutions made with a monochromator, the effect of stray radiation may be significant. The effect of instrumental resolution on Beer's law linearity is discussed in terms of the resolution parameter, which is the ratio of the width of the instrument line shape function to the full width of the band. Measuring the spectrum at low resolution only leads to nonlinear Beer's law behavior when the true peak absorbance is greater than about 0.5. Deviations from Beer's law for measurements made with a Fourier transform spectrometer are strongly dependent on the apodization function that is used. The Norton-Beer medium apodization is recommended for achieving Beer's law linearity over very wide concentration ranges. Keywords: Beer’s law; quantitative absorption spectroscopy; theoretical requirements; chemical deviations; instrumental deviations; optimum transmittance; stray light; effect of resolution; resolution parameter; apodization function; Norton–Beer apodization
Prehistoric human occupation and impacts on Neotropical forest landscapes during the Late Pleistocene and Early/Middle Holocene

This chapter presents a review of the evidence for human occupation and modification of the lowland neotropical forest during the pre-Columbian era. It examines some of the most important factors relating to the occupation and use of tropical landscapes by prehistoric human societies and updates the information presented in the 2006 edition of this book. Late Pleistocene through early and Middle Holocene temporal frames (c. 16 to 5 kcal yr bp) were covered most extensively in the first edition, as these were the periods during which humans colonized both hemispheres of the Americas and agricultural societies emerged and spread throughout the lowland tropical forest.
Role of cell adhesion-associated protein, pinin (DRS/memA), in corneal epithelial migration.

PURPOSE. To determine whether the cellular distribution of cell adhesion-associated protein, pinin, is altered during corneal epithelial migration in response to debridement wounding and to determine the effect of overexpression of pinin in cultured epithelial cells. METHODS. Corneas from guinea pig and embryonic (day 17) chickens were excised, wounded, and placed on organ-culture rafts. At time points from 0 to 24 hours, corneas were cryosectioned and subsequently analyzed by immunofluorescence or immunoelectron microscopy for the presence and distribution of pinin. Cultured epithelial cell line MDCK (Madin Darby canine kidney) confluent monolayers were wounded by scraping and examined by immunofluorescence for pinin and desmoplakin. MDCK cells were transfected with full-length pinin cDNA. After selection in Geneticin, clones of pinin-transfected cells were isolated. Monolayers of transfected cells were scrapewounded and assayed for their ability to migrate. RESULTS. Within 2 hours after wounding, although morphologically identifiable desmosomes were present on migrating epithelial cells, the association of pinin to desmosomes was greatly reduced. Finally, after completion of wound closure, pinin returned to the corneal epithelial desmosome. Wounding of confluent epithelial monolayers (MDCK) in vitro demonstrated a very similar change in the distribution of pinin, whereas desmoplakin remained cell boundary-associated. Transfection of pinin into cultured epithelial cells resulted in an overexpression of pinin. Clones of cells expressing high levels of pinin exhibited marked reduction in their ability to migrate after wounding. CONCLUSIONS. Pinin is involved in corneal epithelium migration. The localization of pinin at or near the desmosome is correlated with the epithelial quiescence. The loss of pinin from the cell boundary correlates with the transition from quiescence to actively migrating. Overexpressing pinin in cultured epithelial cells affects epithelial homeostasis and, in turn, drives the epithelial cells to a hyperstable epithelial adhesive state and inhibits the transition from quiescence to migratory.
Distributed MAC protocols for UWB ad hoc and sensor networks

Large ad hoc and sensor networks impose stringent constraints on cost and energy efficiency. Impulse-based ultra wideband (I-UWB) is an attractive radio technology, and we have developed four medium access control (MAC) protocols to support I-UWB radios in such networks. The four MAC protocols are multichannel ALOHA (M-ALOHA), multichannel pulse sense multiple access (M-PSMA), PSMA with collision avoidance (PSMA/CA), and busy signal multiple access (BSMA). These MAC protocols permit random, distributed medium access with no central point of failure. This paper characterizes the energy efficiency, throughput, and delay of the four protocols. The results suggest appropriate application scenarios for each of the protocols.
The aerospace plane: Its legal and political future

Abstract Recent progress in the development of an aerospace plane calls for consideration of an applicable legal regime. Since the aerospace plane is by definition a hybrid vehicle, it is unclear whether international air space law or outer space law should be applied to it. This article outlines the practical considerations affecting the debate and compares the existing legal principles and rules that might be applied. The author argues that a new allocative theory, which would take account of the purposes of a hybrid vehicle and its actual effects, is needed to determine whether air space law or outer space law should be applied to it.
Chlamydial rRNA operons: gene organization and identification of putative tandem promoters.

Abstract We isolated and characterized the rRNA operons of murine Chlamydia trachomatis. By exhaustively screening a library of chlamydial DNA and by blot hybridization of genomic DNA, we showed that there are only two rRNA operons in C. trachomatis. S1 nuclease protection and primer extension analysis were used to map the 5' and 3' ends of the mature 16S and 23S transcripts in both rRNA cistrons and, additionally, to demonstrate the lack of intervening sequences in these genes. The 5' ends of the presumed primary rRNA transcript were located and found to originate at two tandem sites separated by 100 base pairs. The two tandem chlamydial rDNA transcripts were not differentially regulated. Their products were coordinately expressed and were detectable as early as 9 h postinfection. However, the upstream transcript was only 10% as abundant as the downstream transcript. The sequences surrounding the transcription initiation sites bore little homology with each other or with the classic Escherichia coli -10 and -35 promoter sequences. This finding suggests that chlamydial transcription signals may differ from those of previously studied procaryotes.
Transnationalism and Borderlands: Concepts of Space on the US-Mexico Border and Beyond

Transnationalism and Borderlands: Concepts of Space on the US-Mexico Border and Beyond. This paper problematizes the linkage between studies of international borders and studies of transnationalism. While obvious connections exist, the conceptualization of space by both actors and anthropologists creates a division in Nogales, Arizona, a town on the US-Mexico border and the site of an applied study of education. Implications of this theory for the stated research and for anthropology will be discussed.
Physical distribution and characteristics of meat and bone meal protein

BACKGROUND: Use of meat and bone meal (MBM) in animal feed has been progressively restricted. Production of an MBM protein isolate would facilitate the development of new applications. Rational design of a process to produce such an isolate requires knowledge of MBM protein distribution and characteristics. RESULTS: MBM consists of varying proportions of bone and soft tissue particles, but the soft tissue particles contain > 80% of the protein. Under mild conditions only a small portion of MBM protein can be solubilized; the most aggressive non-hydrolytic conditions fail to solubilize > 55% of the protein. Amino acid analysis reveals that collagen accounts for approximately 17% of the protein in soft tissue particles and 26% of that in bone particles. The extractable fractions of MBM protein are highly polydisperse and have weight-average molecular masses of 71.1–86.7 kDa. CONCLUSION: MBM protein is a challenging substance to utilize functionally, largely due to its low solubility and intermingling with non-protein substances. Results suggest that production of an MBM protein isolate will have to incorporate limited hydrolysis. Copyright © 2008 Society of Chemical Industry
Physiological implications of the Münch‐Horwitz theory of phloem transport: effects of loading rates

Abstract Predicted effects of phloem loading rates on the five profiles of unloading rate, osmotic water flux, pressure, transport speed and concentration, in hypothetical sieve tubes with different sink properties, were calculated using the steady-state mathematical expression of the Munch hypothesis of phloem transport. The prediction that increased loading rates always increases the concentration, and generally increase the speed of translocates through the sieve tube, is emphasized since these parameters are accessible for experimental testing. This particular prediction contrasts with a previous prediction (Tyree, Christy, & Ferrier, 1974), that where concentration was held constant at the loading end, concentration along the rest of the sieve tube would decrease, while speed would increase greatly. Where the unloading mechanism was assigned saturable (enzyme-like) kinetics, increased loading rates (in the range well below the Vmax of the sink) caused both transport speed and concentration to increase. However, as loading rates approached the Vmax of the sinks, speed reached a maximum and then declined, and concentration increased substantially. This was particularly true at very high values of Km, e.g. > 0.1 mol cm−3.
Where Is Digger's Humanity? Black Male Community in Richard Wright's Native Son

(2002). Where Is Digger's Humanity? Black Male Community in Richard Wright's Native Son. ANQ: A Quarterly Journal of Short Articles, Notes and Reviews: Vol. 15, No. 3, pp. 23-30.
Monocytes mediate osteoclastic bone resorption by prostaglandin production.

Monocytes are frequently found adjacent to active bone resorption surfaces in both physiological and pathological situations and may play a key role in bone resorption. There is strong circumstantial evidence that monocytes are precursors for osteoclasts in vivo, and recently they have been shown to resorb devitalized bone directly. The present study shows that monocytes can also resorb bone by stimulation of osteoclasts.
Improving airport security screening checkpoint operations in the US via paced system design

Abstract Since its creation, the Transportation Security Administration, U.S Department of Homeland Security, has tested, and evaluated at least ten passenger screening technologies even though not all of them have been deployed. We evaluate the screening strategies that have been used by focusing on the performance of airport security screening checkpoint operations. A descriptive model is formulated to include design variables and performance measures of the screening process. Based on the real screening time data collected in a range of airports in the US, we develop and apply the speed of inspection operating characteristics curves in the operation simulation and validation processes. A paced system design is proposed to improve the overall performance of the airport screening operations.
Mineralocorticoid Receptor Inhibition Ameliorates the Transition to Myocardial Failure and Decreases Oxidative Stress and Inflammation in Mice With Chronic Pressure Overload

Background— Although aldosterone, acting via mineralocorticoid receptors, causes left ventricular (LV) hypertrophy in experimental models of high-aldosterone hypertension, little is known about the role of aldosterone or mineralocorticoid receptors in mediating adverse remodeling in response to chronic pressure overload. Methods and Results— We used the mineralocorticoid receptor–selective antagonist eplerenone (EPL) to test the role of mineralocorticoid receptors in mediating the transition from hypertrophy to failure in mice with chronic pressure overload caused by ascending aortic constriction (AAC). One week after AAC, mice were randomized to regular chow or chow containing EPL (200 mg/kg per day) for an additional 7 weeks. EPL had no significant effect on systolic blood pressure after AAC. Eight weeks after AAC, EPL treatment improved survival (94% versus 65%), attenuated the increases in LV end-diastolic (3.4±0.1 versus 3.7±0.1 mm) and end-systolic (2.0±0.1 versus 2.5±0.2 mm) dimensions, and amelior...
Rayleigh-based, multi-element coral thermometry: A biomineralization approach to developing climate proxies

Abstract This study presents a new approach to coral thermometry that deconvolves the influence of water temperature on skeleton composition from that of “vital effects”, and has the potential to provide estimates of growth temperatures that are accurate to within a few tenths of a degree Celsius from both tropical and cold-water corals. Our results provide support for a physico-chemical model of coral biomineralization, and imply that Mg2+ substitutes directly for Ca2+ in biogenic aragonite. Recent studies have identified Rayleigh fractionation as an important influence on the elemental composition of coral skeletons. Daily, seasonal and interannual variations in the amount of aragonite precipitated by corals from each “batch” of calcifying fluid can explain why the temperature dependencies of elemental ratios in coral skeleton differ from those of abiogenic aragonites, and are highly variable among individual corals. On the basis of this new insight into the origin of “vital effects” in coral skeleton, we developed a Rayleigh-based, multi-element approach to coral thermometry. Temperature is resolved from the Rayleigh fractionation signal by combining information from multiple element ratios (e.g., Mg/Ca, Sr/Ca, Ba/Ca) to produce a mathematically over-constrained system of Rayleigh equations. Unlike conventional coral thermometers, this approach does not rely on an initial calibration of coral skeletal composition to an instrumental temperature record. Rather, considering coral skeletogenesis as a biologically mediated, physico-chemical process provides a means to extract temperature information from the skeleton composition using the Rayleigh equation and a set of experimentally determined partition coefficients. Because this approach is based on a quantitative understanding of the mechanism that produces the “vital effect” it should be possible to apply it both across scleractinian species and to corals growing in vastly different environments. Where instrumental temperature records are available, a Rayleigh-based framework allows the effects of stress on coral calcification to be identified on the basis of anomalies in the skeletal composition.
Quantitative planar imaging of turbulent buoyant jet mixing

Planar Rayleigh scattering provides quantitative mixing measurements in the developing region of axisymmetric turbulent helium jets issuing into air. The measurements focus on the relatively near field, in which the jets are primarily momentum driven. The imaging parameters are specified to ensure high spatial resolution. The mean jet fluid concentration fields attain self-similarity within the measurement region, though the forms of the mole fraction profiles indicate a reduction in turbulent transport at the jet outer boundary, arising from the reduced jet fluid density. Nevertheless, jet-like scaling pertains for the concentration fields. Mass fraction fluctuations on the jet centreline attain the expected asymptotic value of ≈23 % of the centreline mass fraction values. The scalar dissipation rates, however, show an axial decay rate that is slower than theoretical predictions. The two-dimensional extent of the measurements also allows spatial filtering similar to that inherent in large-eddy simulations (LESs). The results confirm that fluctuation levels and scalar dissipation rates determined for the filtered fields are reduced as the effective resolution is reduced, but while the fluctuation profiles for the filtered fields are similar for the different filter sizes, the forms of the scalar dissipation profiles are highly dependent on filter size. These latter results in particular are of a form that will be useful for grid-dependent assessments of LES results.
Effect of soluble and insoluble fiber diets on serum prostate specific antigen in men.

Purpose:: We assess whether high fiber diets influence serum prostate specific antigen (PSA) related to effects on serum sex hormone levels and fecal steroid excretion.Materials and Methods:: A randomized crossover controlled trial was performed on 14 healthy men with hyperlipidemia on 2 metabolic diets 4 months in duration with each containing foods high in soluble or insoluble fiber and approximately 25 to 30 gm. dietary fiber per 1,000 kilocalories. Serum PSA, free testosterone and estradiol, and fecal bile acid and neutral sterol excretion were evaluated.Results:: Mean serum PSA was lower with the soluble than the insoluble fiber diet (0.07 ± 0.03 ng./ml., p = 0.035). No treatment difference was seen in free testosterone or estradiol, although the latter decreased significantly with the insoluble fiber diet (9 ± 3 pmol./l., p = 0.004). After 16 weeks total fecal bile acid output was greater with the soluble (341 ± 56 mg. daily) compared to the insoluble (203 ± 35, p = 0.001) fiber diet but no differen...
Comparative evaluation of arachidonic acid (AA)- and tetradecanoylphorbol acetate (TPA)-induced dermal inflammation.

The effects of topical application of arachidonic acid (AA) or phorbol ester, tetradecanoylphorbol 13-acetate (TPA), on edema response, vascular permeability, MPO, NAG, and generation of eicosanoids were studied in two murine models of cutaneous inflammation. AA produced a short-lived edema response with a rapid onset that was associated with marked increases in levels of prostaglandins (PGE2, 6-keto-PGF1α, PGF2α), thromboxane B2 (TxB2) and leukotriene B4 (LTB4), with smaller increases in levels of LTC4. TPA produced a longer-lasting edema that was associated with marked influx of neutrophils and predominant formation of LTB4 along with significant changes in levels of TxB2. Circulating T lymphocytes have no apparent role in the acute inflammatory responses induced by either agent. Arachidonic acid-induced vascular permeability preceded the edema response and neutrophil influx, whereas TPA-induced vascular permeability paralleled the edema response and influx of neutrophils. Mast cells appear to be important in the complete expression of inflammatory response, i.e., edema, cellular influx, and vascular permeability induced by either AA or TPA, as these responses were blunted in mast cell-deficient mice. Inhibitors of CO or 5-LO attenuated inflammatory responses in both models. The LTB4 receptor antagonist, SC-41930, inhibited the inflammatory response to TPA but had little effect on that initiated by AA. This suggests that LTB4 is an important mediator in the phorbol ester-induced inflammatory response, whereas peptidoleukotrienes and prostaglandins regulate vascular permeability responses in the arachidonate model.
Role of Autonomic Reflex Arcs in Cardiovascular Responses to Air Pollution Exposure

The body responds to environmental stressors by triggering autonomic reflexes in the pulmonary receptors, baroreceptors, and chemoreceptors to maintain homeostasis. Numerous studies have shown that exposure to various gases and airborne particles can alter the functional outcome of these reflexes, particularly with respect to the cardiovascular system. Modulation of autonomic neural input to the heart and vasculature following direct activation of sensory nerves in the respiratory system, elicitation of oxidative stress and inflammation, or through other mechanisms is one of the primary ways that exposure to air pollution affects normal cardiovascular function. Any homeostatic process that utilizes the autonomic nervous system to regulate organ function might be affected. Thus, air pollution and other inhaled environmental irritants have the potential to alter both local airway function and baro- and chemoreflex responses, which modulate autonomic control of blood pressure and detect concentrations of key gases in the body. While each of these reflex pathways causes distinct responses, the systems are heavily integrated and communicate through overlapping regions of the brainstem to cause global effects. This short review summarizes the function of major pulmonary sensory receptors, baroreceptors, and carotid body chemoreceptors and discusses the impacts of air pollution exposure on these systems.
Explicit expressions of transient elastodynamic crack tip fields for mixed-mode crack propagation

Abstract Explicit results are presented for transient, mixed-mode, plane elastodynamic crack tip fields around a rapidly propagating crack in a homogeneous, isotropic and linearly elastic solid. Expressions for stresses and displacements are composed of steady-state terms and corresponding transient corrections and are put in the form of asymptotic series expansions (up to six terms) in terms of crack tip polar coordinates.
The Cultural Psychology of Natural Kinds and the Deconstruction of the Emotions: A Comment:

Stimulated by these three brilliant target essays this commentary raises a few questions about the universality of the “emotions,” the cultural psychology of “natural kinds,” and the analytic deconstruction of the idea of an emotion.
Establishing Validity and Reliability of an Instrument Using the Theory of Planned Behavior to Predict Middle School Student Obesity-Related Actions:

Background:Childhood obesity is of concern to many health professionals, parents, teachers, and school administrators because of the negative impact on the child's physical, psychological, and beha...
Classification of Vectorcardiograms Using Walsh And Cosine Orthogonal Transforms

In this study, the usefulness of two-dimensional transforms in classifying human vectorcardiograms is investigated. The transforms used are the Walsh-Hadamard (WHT) and the discrete cosine (DCT). Experimental results included in the paper demonstrate that about 80-85 percent correct classification may be achieved.