cssi/SciSciGPT-SciSciNet huggingface dataset:
Longitudinal Dynamic Stability

Longitudinal dynamic stability addresses the time history of motion following a disturbance in pitch. This chapter summarizes the most commonly used approach to analyze the two predominant longitudinal dynamic stability modes, usually referred to as the short period and phugoid. A review of the development of the six non-linear aircraft equations of motion, along with a review of the three linearized longitudinal equations is a realistic prerequisite for the reader. A significant degree of importance is placed on obtaining excellent longitudinal dynamic stability characteristics in an aircraft design, with special emphasis on the short period mode, since the pilot's ability to accomplish tracking and maneuvering tasks is directly affected by these characteristics. In recent decades, baseline aircraft dynamic stability characteristics have been typically compromised in aircraft designs. This design compromise has been chosen in favor of decreased drag to obtain performance improvements such as increased range, endurance, and turning performance, with the knowledge that feedback control systems will be added to the design to “modify” the baseline dynamic stability and obtain excellent dynamic stability or handling quality characteristics. Keywords: equations of motion; short period; phugoid; damping ratio; natural frequency; characteristic equation
On the Optimal Order of Stations in Tandem Queues

Consider m nonidentical service stations which have to be set up in a sequence j1, J2,..., jm. At time t = 0 the system is empty and there is an infinite number of customers waiting in front of station j1. Customers have to be served first at station j1, after finishing service there they have to go through station j2, etc. Both the cases of infinite waiting room and of zero waiting room between the stations are considered; in the case of zero waiting room, blocking may occur. We study how the output process depends on the sequence in which the stations are set up.
Indeterminate Probability and Change of View

This paper argues that if changes in confirmational commitment (or changes in prior probabilities) are to be defended without begging the question, indeterminacy in probability judgment is required. But no other modification of strict Bayesian doctrine is needed. The resulting qualified version of the Bayesian approach is compared with the way indeterminacy is deployed in the theory of H.E. Kyburg who uses a fixed confirmational commitment but, nonetheless, invokes indeterminacy. An important motivation for introducing indeterminacy in probability judgment is the need to address the question of how and when probability judgments should be changed. I shall not attempt to address the question of change in probability judgment in detail here but only to explain why the very formulation of the question calls for a consideration of indeterminacy. X's degree of credal or subjective or personal probability that h is true reflects X's judgment at a time of how much to risk on the truth of h or X's degree of certainty. But such credal probability judgments are themselves fine grained discriminations between propositions that X judges possibly true where "possible" means consistent with X’s state of full belief K.
"Making Space for 'Real' Diversity within the Classroom"

This paper discusses concrete approaches for faculty to use when teaching a student body whose demographics are significantly different from the identity of the professor. As a white northern political scientist teaching at a historically black southern university, this work particularly emphasizes the dynamics of race and gender. However, the lessons from this essay are applicable to all of us who need to construct space in which our students can challenge their own preconceived notions. This concern is particularly pertinent to me in that I teach classes on race, law, and western political thought. If the United States and other pluralistic democracies claim that our very strength is found in the sharpening of our ideas against competing ideas to best approximate the truth, how can we replicate this process in our increasingly diverse classrooms? What might this dynamic look like when the professor at the front of the room is radically different in significant ways from the students they teach? What this means for our classroom is that pluralism must be real—it does not preclude the search for truth and right—it just makes it more complicated and realistic. We cannot merely construct truth in our own images; we must confront challenging contradictions. In the United States, this requires us to take seriously the competing arguments and frameworks presented by the other, generally reflecting issues of race, class, and gender. This talk will examine five elements which I advocate are needed to ensure that this process of pluralistic discussion and discovery is actually occurring in our university and college classrooms. More particularly, the paper examines the potential for classroom engagement in the area of diversity when we consider the factors of audience, grace, power, discomfort, and transformation.
George Martin at The Boston Consulting Group (A)

George Martin, managing partner at The Boston Consulting Group, is worried as some of his best performers have recently pulled him aside to discuss the challenges they face managing the demands of their work lives with their desire for more predictable time with their families. BCG had instituted multiple initiatives to help its consulting staff better achieve work-life balance, yet some of Martin's top consultants still struggled. The case considers the challenges professional service firm employees face in terms of work-life issues.
Alloy Design Strategies Through Computational Thermodynamics and Kinetics Approaches

In this work, we present an example in which computational thermodynamics and kinetics can be used, in conjunction with experiments and models for predicting the mechanical response of microstructure to design alloys and processing parameters in the spirit of the Materials Genome Initiative and the Integrated Computational Materials Science and Engineering (ICME) framework. Specifically, we describe the optimization of strength and ductility of so-called Transformation Induced Plasticity (TRIP) steals. We show how we can use models to predict the phase constitution of complex TRIP microstructures as a function of alloying and processing. We briefly describe how we can use experiments and simple models to relate phase constitution (amount of phases and their composition) to properties/performance. Finally, we show how we can use the established alloy/processing-microstructure-properties relations to determine alloying and processing parameters that yield optimal mechanical properties.
Investigation of phonemic context in speech using self-organizing feature maps

Some experiments with a neural-network model based on the self-organizing feature map algorithm are described. The main problem in phonemic recognition is the overlapping of feature vectors due to variability of speech and due to the coarticulation effect. This property of speech is reflected in the self-organized neural-network model in that a network unit can respond to more than one phonemic class. The authors have shown for their database that the sequence of responding units is consistent and similar for isolated utterances of the same word and distinct for different words. Thus, recognition can be based on network sequence identification. However, it is desirable that this sequence be somewhat simplified. Toward this goal they propose an algorithm for sequence smoothing. It is proposed that this network can be used as the feature extraction stage of another neural network that can learn the responding sequences as part of a speech recognition system. >
A view on EOS

I am replying to the recent solicitation to provide views on NASA's Earth Observing System (EOS) to an AGU panel (Eos, October 3, p. 886). My view concerns Landsat. A flashy EOS poster, recently distributed, features six images from space; three of these are from the Landsat satellite. Yet no Landsat-type imaging system is contemplated for EOS. Imaging systems such as HIRIS and HRIS (high-resolution imaging spectrometers) do not give the synoptic view of Landsat and are much too elaborate for simple but invaluable observations of many global- scale processes.
A heuristic for the multiple tour maximum collection problem

Abstract The multiple tour maximum collection problem (MTMCP) consists of determining the m optimal time constrained tours which visit a subset of weighted nodes in a graph such that the total weight collected from the subset of nodes is maximized. In this paper, a heuristic for the MTMCP is developed. The results of computational testing reveal that the heuristic has three very attractive features. First, the heuristic will always produce a feasible solution if one exists. Second, the heuristic produces very good solutions. In most cases where the exact solution is known, it produces the optimal solution. And finally, the heuristic has the ability to handle large problems in a very short amount of computation time.
Hydrostatic balloon dilation of a terminal ileal stricture secondary to Crohn’s disease

Une observation, resultats satisfaisants a court terme. Il s'agit d'une categorie tres particuliere de maladie de Crohn
Improved Elicitation of Neutralizing Antibodies against Primary Human Immunodeficiency Viruses by Soluble Stabilized Envelope Glycoprotein Trimers

Human immunodeficiency virus (HIV-1) envelope glycoprotein subunits, such as the gp120 exterior glycoprotein, typically elicit antibodies that neutralize T-cell-line-adapted (TCLA), but not primary, clinical isolates of HIV-1. Here we compare the immunogenicity of gp120 and soluble stabilized trimers, which were designed to resemble the functional envelope glycoprotein oligomers of primary and TCLA HIV-1 strains. For both primary and TCLA virus proteins, soluble stabilized trimers generated neutralizing antibody responses more efficiently than gp120 did. Trimers derived from a primary isolate elicited antibodies that neutralized primary and TCLA HIV-1 strains. By contrast, trimers derived from a TCLA isolate generated antibodies that neutralized only the homologous TCLA virus. Thus, soluble stabilized envelope glycoprotein trimers derived from primary HIV-1 isolates represent defined immunogens capable of eliciting neutralizing antibodies that are active against clinically relevant HIV-1 strains.
PROPERTIES OF HUMAN PLASMIN

Several aspects of the properties and preparation of human plasmin are considered. It appears that glycerol activation of the proenzyme is a peculiar property dependent in part on the structure of the glycerol molecule since closely related compounds are without effect. Observations on the influence of ionic strength, on ion activation and inhibition of the enzyme, on substrate specificities, and on preparative procedures are recorded and comparisons with similar data on related bovine enzymes are made.
Digital natives and digital media in the college classroom: assignment design and impacts on student learning

The use of multimodal learning techniques is becoming more widespread, however, the pedagogical discourse surrounding its implementation into classroom and course design is complicated as these technologies are either demonized or viewed as the panacea for curriculum ills. Educators are faced with unique challenges when investigating how to experiment with the best ways to produce classroom experiences that use digital media. This case study examines the implementation challenges and learning outcomes related to such an experiment by reviewing and assessing the use of digital media in a health communication course, specifically through the development of documentaries. Creating an effective assignment requires addressing the development of technical skills along with course content and providing guidance and feedback throughout a semester-long project. Creating an effective assignment is pointless without sufficient learning outcomes. Because this assignment engaged students with both the course content a...
Estradiol and a selective estrogen receptor modulator affect steroid hormone receptor messenger RNA levels and turnover in explant cultures of sheep endometrium.

Estrogens upregulate estrogen receptor (ER) and progesterone receptor (PR) gene expression in endometrium immediately before ovulation to prepare, it for nurturing embryos. Most in vitro model systems have lost the ability to upregulate expression of the ER gene in response to estradiol (E2) or the ability to express the ER gene at all. Here, we used explant cultures from control and E2-treated ewes and assessed expression of four genes (ER, PR, glyceraldehyde 3-phosphate dehydrogenase [GAPDH], and cyclophilin [CYC] genes) that are upregulated by E2 in vivo on Northern blots. In cultures from control and E2-treated ewes, ER and PR messenger ribonucleic acid (mRNA) levels dropped significantly during 24 h of culture in the absence of E2. Glyceraldehyde 3-phosphate dehydrogenase mRNA levels increased 300% in explants from control ewes to match the higher levels in the endometrium of the E2-treated ewe (in vivo and in explant culture). The only effect of E2 in the explant cultures was to prevent the decrease in PR mRNA. The new selective ER modulator, EM-800 (EM), decreased ER and PR mRNA levels in explants from control ewes but upregulated GAPDH and CYC mRNA levels. The EM treatment in vitro mimicked that of E2 by increasing the half-life of ER mRNA in endometrial explants. These data illustrate distinct, gene-specific effects of the explant culture process, E2, and EM on the expression of endometrial genes.
Induced optical anisotropy fluctuation in the lens of the eye

Abstract It has been shown that under three different experimental conditions—(1) disorganization of lens fibers, (2) swelling, and (3) experimentally induced galactose cataract formation—the lens of the eye demonstrates a I+ component of scattered light that is the sign of optical anisotropy fluctuation.
A feedback control approach to maintain consumer information load in online shopping environments

The heterogeneity of e-commerce users requires online shopping environments to advance from a simple framework to one that is adaptive. This need results from the negative consequences of user frustration due to information load. We used a feedback control theory based approach to address the online consumer information overload issue in an adaptive manner. To demonstrate the efficacy of this feedback control approach, a design science method evaluated the feedback controller. The main effect was that the dynamic adaptivity did not have to rely on summarizing data for inference to the individual. The proposed feedback control design is therefore a robust and viable option for organizations to incorporate into their online shopping environments to accommodate user variation of information load for e-commerce adaptivity.
High prevalence of p53 exon 4 mutations in soft tissue sarcoma

BACKGROUND p53 is the most commonly mutated gene in cancer, including soft tissue sarcoma (STS). The authors characterized p53 alterations (protein accumulation and gene mutation) in STS to evaluate possible associations with patient outcomes. METHODS Thirty-one STS specimens (multiple histologies) were analyzed by p53 immunohistochemistry (IHC) and direct DNA sequencing of p53 exons 2–11 and then correlated with outcomes. RESULTS Direct p53 sequencing detected mutations in 10 of 31 STSs; 7 of 10 were missense mutations, whereas 3 of 10 were either insertions or frameshift mutations, leading to nonfunctional truncated p53; 7 of these p53 mutations have not been previously described. Four p53 exon 4 mutations were identified, a p53 region previously unknown to be mutation prone. Eighteen of the 31 specimens expressed p53 when the authors used the clinical IHC assay of their institution. Interassay concordance of 48% was observed; only 6 of 10 sequencing-identified p53 mutated specimens exhibited nuclear p53 protein expression by IHC, whereas 12 of 18 specimens exhibiting p53 protein expression by IHC harbored sequencing-identified wild-type p53. Decreased survival was observed in STS patients bearing sequencing-identified mutated p53 versus wild-type p53, as was a correlation between IHC-determined nuclear p53 protein expression and decreased survival. CONCLUSIONS p53 protein stabilization and p53 mutation frequently occur in STS, and both suggest worse outcomes for patients so affected. However, increased p53 protein expression does not necessarily indicate p53 gene mutation. The high incidence of exon 4 mutations found in STS suggests that p53 sequencing should not be limited to the core DNA binding domain. Cancer 2007. © 2007 American Cancer Society.
Acute care of severe tooth fractures

Teeth that are severely fractured and demonstrate vital tissue at the fracture line may be treated acutely by extirpating the pulp. This technique leaves the patient free of pain until secondary care is available.
Comparison of the Polymerase Chain Reaction Using Genus-Specific Oligonucleotide Primers and Microbiologic Culture for the Detection of Salmonella in Drag-Swabs from Poultry Houses

Drag-swab samples were collected from 18 poultry houses at 9 broiler farms. Fifty drag-swab samples were tested for Salmonella by microbiologic culture using selective enrichment and the polymerase chain reaction (PCR) with oligonucleotide primers specific for all members of the genus Salmonella. Drag-swab samples were tested for Salmonella using PCR before and after enrichment. Only one sample was positive by PCR prior to enrichment. Forty-seven of the drag-swabs samples tested after enrichment were positive for Salmonella using PCR, and 29 were positive by microbiologic culture. All but one of the culture-positive samples were positive by PCR; this discordant sample was classified as indeterminate by PCR. Salmonella was identified in houses from all nine farms by PCR and eight of nine farms by microbiologic culture. Salmonella was found in all 18 houses by PCR and in 15 of 18 houses by microbiologic culture. In this study, PCR was significantly (P < .001) more sensitive than culture for environmental monitoring of Salmonella using drag-swabs.
Conventional controller design for industrial robots — A tutorial

Industrial robots are serial link manipulators whose dynamic characteristics are highly nonlinear. By controlling each link or joint individually, employing the conventional technique to design linear feedback controllers for the robot is possible. The gravitational force and force interactions between joints are suppressed by precalculated feedforward compensation. To ease the computational burden, the compensating signals are either approximated or their computational formulas are simplified.
Vitamin a deficiency in Brazil: Perspectives for food production oriented interventions

A vitamin A deficiency problem exists in Brazil, but it does not appear to be associated with the degree of blinding sequela found in Asia and Africa. Xerophthalmia does occur in the semi‐arid “sertao” region of the Northeast, but more in children under two years of age, as compared with the three to five years of age of Asia and Africa. This difference may be related to the shorter duration of breast feeding in the Northeast of Brazil. Many but not all Northeastern states are employing massive dose capsule distribution to combat vitamin A deficiency, but all seek a more long term solution. The Brazilian diet is both quantitatively and qualitatively deficient in vitamin A. Rural diets are poorer in vitamin A than urban diets. In the south of Brazil dairy products are the principal dietary Vitamin A source and responsible for most of the variability associated with income and location. In the northeast where Vitamin A intakes are lowest, plant foods are the more important sources of vitamin A. Many availab...
Ammonium Requirement for Embryogenesis in vitro

PREVIOUS work on tissue cultures of the wild carrot has shown that the embryogenesis which occurs in such cultures is not fundamentally different from the same process in the ovule1,2. It has also been shown that undifferentiated pro-embryos, sieved from callus, will continue to grow in a disorganized non-polar fashion if they are exposed to a concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) which is higher than 0.1 mg/1. (ref. 3). Lowering the 2,4-D concentration permits histological differentiation and polarized growth to occur. It is thus possible to establish a crude control over the process of embryogenesis by suitable alterations of the 2,4-D concentration. While this technique has provided an experimental system in which the simultaneous development of numerous embryos can be examined, it has provided no information on the morphogenetic factors which initially cause cultured cells to behave as zygotes.
The future of U.S. private sector unionism: Did George Barnett get it right after all?

George Barnett has the unenviable reputation of making one of the most ill-timed, inaccurate forecasts in the history of industrial relations. Only six months after predicting trade unionism would further decline in the U.S., union organizing swept over the nation in mid-1933 and union density jumped nearly three-fold in the course of a decade. While Barnett's forecast was wildly at odds with the course of unionism in the shortmedium run, viewed over the long run (i.e., the remainder of the twentieth century) it appears more prescient. When he made his prediction, private sector union density stood at roughly 12 percent; seventy years later it is at 9 percent.
Total collapse of the heart.

An approximately 30 year-old Ugandan male was found unresponsive on an American base in Iraq. The patient was altered and combative with no signs of trauma. A chest x-ray was performed showing an enlarged cardiac silhouette and pulmonary edema. The patient required intubation during which a large amount of edema fluid was produced. A computed tomography (CT) (Figure) showed severe calcifications of both the aortic and mitral valves. Figure. Intravenous contrast enhanced computed tomography of the chest showing severe calcifications (arrows) of both aortic (A) and mitral (B) valves. Shortly after CT the patient went into cardiac arrest. The patient had a bedside echocardiogram showing severe bi-valvular heart failure and died shortly thereafter. The diagnosis of rheumatic heart disease with severe cardiomyopathy was considered the most likely cause of his presentation. Rheumatic heart disease is a major cause of cardiovascular death in developing countries and affects between 15 and 20 million people worldwide.1 The disease is a sequella of one or more episodes of acute rheumatic fever with subsequent valvular calcification and damage. The pathophysiology is felt to be an aberrant immune response to certain strains of Streptococcus pyogenes infection. The mitral valve is most commonly affected, but aortic valve involvement is also seen as the disease progresses. Patients may not recall any preceding events and present with shortness of breath between ages 20 and 50.1 Diagnosis of rheumatic disease is often made by echocardiogram when the diagnosis is suspected. Without intervention, the disease progresses to severe valvular disease with heart failure.
Quantity and distribution of eosinophils in the gastrointestinal tract of children.

Abstract There are a lack of data on the quantity and location of eosinophils in the gastrointestinal tract of healthy individuals. Accordingly, we examined gastrointestinal biopsies obtained during endoscopic evaluation of pediatric patients. Biopsies were previously interpreted as having no diagnostic abnormality. The presence of extracellular eosinophil constituents and the quantity of eosinophils in atopic versus nonatopic individuals was determined. In the esophagus, eosinophils were present in only 2.7% of high-power fields (hpf), with a mean value of 0.03 ± 0.10 eosinophils/hpf (mean ± standard deviation) and a maximum of 1 eosinophil/hpf. Examination of the antrum and fundus revealed similar numbers of eosinophils in the lamina propria (1.9 ± 1.3 and 2.1 ± 2.4 eosinophils/hpf, respectively), with no eosinophils observed in the surface epithelium. In the small intestine, there were 9.6 ± 5.3 (maximum, 26 eosinophils/hpf) and 12.4 ± 5.4 eosinophils/hpf (maximum, 28 eosinophils/hpf) in the intercrypt...
Impact of Planting Date and Hybrid on Early Growth of Sweet Corn

Sweet corn (Zea mays L. var. rugosa) is a warm-weather crop that is grown in most of the United States. Normally, it is planted over an extended planting window to provide a continuous supply for the fresh market. However, this planting window exposes the crop to various stresses and weather risks. The objective of this study was to determine the effect of planting date on early growth of sweet corn with different maturities for different environmental conditions in Georgia, USA. Three yellow sweet corn genotypes, including a full homozygous sugar enhanced (se), a super sweet (sh2), and a standard or normal (su), were compared in 2004, 2005, and 2006 in two locations in Georgia. The experiment consisted of one planting date in 2004, six in 2005, and four planting dates under two water regimes in 2006. Plant growth variables that were measured included leaf area index (LAI), canopy height, and aboveground biomass from emergence to the beginning oftasseling. The growth rate as a function of thermal time (TT) was used to determine the impact of planting date on growth of sweet corn. A base temperature (T b ) of 6.6°C for the three genotypes, obtained from experimental data, was used. Days to emergence varied from 4 to 12 for the warmest and coolest growing seasons, respectively. The growth of the three sweet corn genotypes showed a clear response to planting dates as LAI, canopy height, and aboveground biomass and the individual plant components, including stem, sheath, and leaves were significantly (P < 0.05) different at the beginning oftasseling. For all experiments, the longer the maturity group, the higher the total aboveground biomass. Significant differences (P < 0.05) for growth rate were found between planting dates, genotypes, plant components and their interactions. The short-season hybrid tended to have a faster overall plant growth rate of all individual plant components during the warmer seasons. In contrast, the mid- and full-season hybrids tended to have a higher growth rate during the cooler seasons. For rainfed conditions, the short-season hybrid had higher leaf and sheath growth rates than the mid-and full-season hybrids, resulting in a higher stem growth rate. These results indicate that the effect of planting date on early growth of sweet corn is of significance, as it may lead to identification of an optimum planting window for this crop.
The cytohesin coiled-coil domain interacts with threonine 276 to control membrane association

Cell migration is regulated by a number of small GTPases, including members of the Arf family. Cytohesins, a family of Arf-activating proteins, have been extensively implicated in the regulation of Arfs during migration and cell shape change. Membrane association of both the Arf and its activating protein is a prerequisite for Arf activation. Therefore regulating the extent of cytohesin membrane association is a mechanism for controlling the initiation of cell movement. We have discovered a novel intramolecular interaction that controls the association of cytohesins with membranes. The presence of the coiled-coil domain reduces the association of cytohesin 2 with membranes. We demonstrate that this domain interacts with more C-terminal regions of the protein. This interaction is independent of another previously identified autoinhibitory conformation. A threonine residue (T276) in the cytohesin 2 PH domain is a target for phosphorylation by Akt. Mutation of this threonine to aspartic acid, to mimic phosphorylation, disrupts the binding of the coiled-coil domain to c-terminal regions and promotes membrane association of cytohesin 2. The presence of a second autoinhibitory interaction in the cytohesins suggests that these proteins can act a signal integrators that stimulate migration only after receive multiple pro-migratory signals.
aIRPLane: an information retrieval pattern language

Interaction patterns and pattern languages have been discussed for years in HCI literature yet there have been few empirical studies conducted. We describe aIRPLane: An Information Retrieval Pattern Language, its discovery, and the experimental design we use to examine its impact on the design of information retrieval interfaces. The results of a pattern sorting exercise are the focus of this paper.
Bio-inspired scanning for video-imaging using an atomic force microscope

Atomic Force Microscopy (AFM) is a powerful tool that can perform nano-scale imaging. Normally AFM tip is controlled to scan on sample surface line by line to get the topographic image and this process takes several minutes. Higher sample rate is demanded so that when doing continuous imaging, the time interval between each image can be significantly shorted thus video-imaging can be achieved. In this paper, a compressive sensing based AFM video-imaging system is built, and random walk based scanning path is proposed. Compressive sensing requires random sampling. Bio-inspired random walk based scan path is able to provide a random tip moving path, which enables compressive sensing to be implemented into AFM scanning system. Experiments based on this system are set up in order to test the performance. It first raster scan the entire area and then generate a biased random tip moving path focusing on some specific areas. Compressive scan is then used to continuously scan the sample surface. Finally, video-imaging is achieved and dynamic changes in nano-scale are observed.
Ultrahigh-Resolution, Wide-Field-Of-View Rb Optical Filter For The Detection Of Frequency-Doubled Nd Lasers

We report a simple theoretical model for the calculation of the dependence of filter quantum efficiency versus laser pump power in an atomic Rb vapor laser-excited optical filter. We present the calculations for a Rb filter transitions that can be used to detect the practial and important frequency-doubled Nd lasers. The results of these calculations show the filter's quantum efficiency versus the laser pump power. The laser pump powers required range from 2.4 to 60 mW per square centimeter of filter aperture.
Fabrication techniques for a novel three-dimensional monolithic integrated circuit transmission line in silicon

A novel integrated circuit transmission line, trench waveguide, has been developed for high frequency/high speed applications. The three-dimensional structure is suitable as a low impedance interconnect. The fabrication process developed uses special wet etch, and angle evaporation techniques. Measurements on large-scale models of the device yielded impedances as low as 12 Omega . >
The Snail Repressor Inhibits Release, Not Elongation, of Paused Pol II in the Drosophila Embryo

Summary The development of the precellular Drosophila embryo is characterized by exceptionally rapid transitions in gene activity, with broadly distributed maternal regulatory gradients giving way to precise on/off patterns of gene expression within a one-hour window, between two and three hours after fertilization [1]. Transcriptional repression plays a pivotal role in this process, delineating sharp expression patterns (e.g., pair-rule stripes) within broad domains of gene activation. As many as 20 different sequence-specific repressors have been implicated in this process, yet the mechanisms by which they silence gene expression have remained elusive [2]. Here we report the development of a method for the quantitative visualization of transcriptional repression. We focus on the Snail repressor, which establishes the boundary between the presumptive mesoderm and neurogenic ectoderm [3]. We find that elongating Pol II complexes complete transcription after the onset of Snail repression. As a result, moderately sized genes (e.g., the 22 kb sog locus) are fully silenced only after tens of minutes of repression. We propose that this "repression lag" imposes a severe constraint on the regulatory dynamics of embryonic patterning and further suggest that posttranscriptional regulators, like microRNAs, are required to inhibit unwanted transcripts produced during protracted periods of gene silencing.
Prelaunch Calibration of the NOAA-11 AVHRR Visible and Near IR Channels

Abstract The prelaunch radiometric sensitivities of Channels 1 and 2 of the NOAA-11 Advanced Very High Resolution Radiometer (AVHRR) were measured by the manufacturer, ITT, in late 1981 and in April 1988, and the satellite was launched on 24 September 1988. The results are presented here to make them more generally accessible, to inform data users of changes in the previously published results (NOAA, 1988), and to indicate their precision.
MKP-1 switches arginine metabolism from nitric oxide synthase to arginase following endotoxin challenge.

l-Arginine (l-arg) is metabolized to nitric oxide (NO) by inducible NO synthase (iNOS) or to urea and l-ornithine (l-orn) by arginase. NO is involved in the inflammatory response, whereas arginase ...
Relationship between Enterococcal Levels and Sediment Biofilms at Recreational Beaches in South Florida

ABSTRACT Enterococci, recommended at the U.S. federal level for monitoring water quality at marine recreational beaches, have been found to reside and grow within beach sands. However, the environmental and ecological factors affecting enterococcal persistence remain poorly understood, making it difficult to determine levels of fecal pollution and assess human health risks. Here we document the presence of enterococci associated with beach sediment biofilms at eight south Florida recreational beaches. Enterococcal levels were highest in supratidal sands, where they displayed a nonlinear, unimodal relationship with extracellular polymeric secretions (EPS), the primary component of biofilms. Enterococcal levels peaked at intermediate levels of EPS, suggesting that biofilms may promote the survival of enterococci but also inhibit enterococci as the biofilm develops within beach sands. Analysis of bacterial community profiles determined by terminal restriction fragment length polymorphisms showed the bacterial communities of supratidal sediments to be significantly different from intertidal and subtidal communities; however, no differences were observed in bacterial community compositions associated with different EPS concentrations. Our results suggest that supratidal sands are a microbiologically unique environment favorable for the incorporation and persistence of enterococci within beach sediment biofilms.
Intermittent turbulence in the solar wind

This paper demonstrates the existence of intermittent turbulence in the solar wind at 8.5 AU. The pth-order velocity structure functions show scaling behavior in the range of periods from 0.85 hour to 13.6 hours for p of less than 20. The exponent of the scaling law s(p) is a quadratic function of p. These observations of s(p) for compressible MHD turbulence on a scale of the order of about 1 AU are consistent with laboratory measurements of s(p) for gasdynamic turbulence on a scale of the order of 1 m, indicating the universal character of intermittent turbulence. The observations are not described by the 'constant beta' model of intermittent turbulence. They are marginally consistent with the lognormal model. The observations are consistent with a random beta model prediction which assumes that the turbulence is a mixture of sheets and space-filling eddies.
Neither monstrous nor pastoral, but scary and sweet: Some thoughts on sex and emotional performance in Intimacies and What Do Gay Men Want?

This extended meditation on David Halperin's What Do Gay Men Want? and Leo Bersani and Adam Phillips’ Intimacies focuses on how these theorists think about sex, more than sexuality: how they use the ways that sex disorganizes the subject (abjection, impersonal narcissism) to ground strong accounts of better sociality at the scale of the personal and the political. The essay investigates the potentiality embedded in optimism about sex when it's not a drama but a scene of lightness and the comic.
Trace element distribution in US groundwaters: a probabilistic assessment using public domain data

A large database of dissolved-fraction groundwater concentrations for Ag, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Se, Tl, Sn, V and Zn was constructed using public domain data. Data analysis techniques for multiply-censored sample populations were used to extract salient information regarding sample populations from the raw data. The results of this work show that trace element concentrations are approximately log-normally distributed. Median values for <90% censored sample populations range from 0.2 to 35 μg l−1. Minimum to maximum concentrations range as high as 7 orders of magnitude for certain elements (e.g. Zn). This work provides a rapid, cost-effective screening tool for evaluating groundwater quality based on observed trace element concentration data.
The Role of Decay Accelerating Factor in Environmentally Induced and Idiopathic Systemic Autoimmune Disease

Decay accelerating factor (DAF) plays a complex role in the immune system through complement-dependent and -independent regulation of innate and adaptive immunity. Over the past five years there has been accumulating evidence for a significant role of DAF in negatively regulating adaptive T-cell responses and autoimmunity in both humans and experimental models. This review discusses the relationship between DAF and the complement system and highlights major advances in our understanding of the biology of DAF in human disease, particularly systemic lupus erythematosus. The role of DAF in regulation of idiopathic and environmentally induced systemic autoimmunity is discussed including studies showing that reduction or absence of DAF is associated with autoimmunity. In contrast, DAF-mediated T cell activation leads to cytokine expression consistent with T regulatory cells. This is supported by studies showing that interaction between DAF and its molecular partner, CD97, modifies expression of autoimmunity promoting cytokines. These observations are used to develop a hypothetical model to explain how DAF expression may impact T cell differentiation via interaction with CD97 leading to T regulatory cells, increased production of IL-10, and immune tolerance.
United States trade and possible restrictions in high-technology products

Abstract This paper assesses the changing U.S. competitive position in high-technology products, and examines reasons for changes. It then inquires into the potential value of restrictive trade policies for promoting the U.S. interest in this sector, including mutual restrictions between the U.S., the EC, and Japan. The paper shows that the U.S. market share in most high-technology products, while still high, is declining. While industrial policy in other countries may have been a facilitating factor in this adverse development, the main explanation appears to lie in changing factor endowments, particularly the marked increase in the human capital/labor endowment ratios of Japan and Germany relative to that of the United States. When considering all the criteria relevant to trade policy, the differences between the high-technology industries bring into question the validity of lumping them into one sector for the purpose of strategic trade policy. Each industry needs to be treated separately. Their main common characteristic is intensity in human capital input. When they are viewed as one sector, a move to redress the declining U.S. lead calls for a domestic rather than a trade policy: massive U.S. investment in human capital and in research and development of the post-sputnik variety.
Spatially localized electronic structure in polyaniline by scanning tunneling spectroscopy

Abstract Variations of local electronic structure of fully and partially protonated emeraldine hydrochloride films, as determined by tunneling spectroscopy in a scanning tunneling microscope, are compared. Two types of electronic structure predominate, a highly conductive metallic-like, and a less conductive semiconductor-like structure. These variations were observed on length scales of tens of nanometers. Additionally, some measurements provide evidence for the existence of regions with a locally stable bipolaron configuration. Implications of these first observations of spatial variations of electronic structure in an amorphous organic material to the conduction mechanisms proposed for polyaniline are discussed.
Radiation damage in thin films of high Tc superconductors

Using O and As ions, we have investigated the effects of ion irradiation on the superconducting, electrical and microstructural properties of thin films of Y1Ba2Cu3Ox. Superconducting transitions were found to degrade in polycrystalline films by a decoupling of the superconducting grains while epitaxial films degrade due to bulk damage. Damage in the films was a result of elastic rather than electronic processes. Evidence is presented for 1D normal conductivity in the films.
The Cosserat eigenfunctions for the elliptic exterior problem with applications to thermoelasticity and Stokes flow

The Cosserat eigenvalue problem for the elliptic exterior is considered. It is shown that the only Cosserat eigenvalue different from the infinite multiple eigenvalues \(\tilde \omega = - 1\) and \(\tilde \omega = \infty \) is \(\tilde \omega = - 2\) which also has an infinite multiplicity. The orthogonal basis of the eigenspace corresponding to \(\tilde \omega = - 2\) is constructed. Application to thermoelasticity and Stokes flow – extensional and shear – past a rigid elliptical cylinder are presented and agreement is obtained with classical solutions for a circle. The fact that the solutions consist of only two eigenfunctions reveals the efficiency of the method.
Laser-tweezer-controlled solid immersion lens for high-resolution imaging in microfluidic and biological samples

A novel technique is presented which integrates the capacity of a laser tweezer to optically trap and manipulate objects in three-dimensions with the resolution-enhanced imaging capabilities of a solid immersion lens (SIL). Up to now, solid immersion lens imaging systems have relied upon cantilever-mounted SILs that are difficult to integrate into microfluidic systems and require an extra alignment step with external optics. As an alternative to the current state-of-art, we introduce a device that consists of a free-floating SIL and a laser optical tweezer. In our design, the optical tweezer, created by focusing a laser beam through high numerical aperture microscope objective, acts in a two-fold manner: both as a trapping beam for the positioning and alignment of the SIL and as an near-field scanning beam to image the sample through the SIL. Combining the alignment, positioning, and imaging functions into a single device allows for the direct integration of a high resolution imaging system into microfluidic and biological environments.
Dolomite in flexure-fractured petroleum reservoirs in New Mexico and Colorado

X-ray diffraction, thin-section, and titrimetric analyses have been performed on samples from wells completed in structurally induced fractured zones of the West Puerto Chiquito pool in New Mexico. Results indicate that production is restricted to fractures in dolomite-rich sandy layers in the Upper Cretaceous Niobrara Member of the Mancos Shale rather than to fractures in competent limestone layers interbedded with more plastic shales, as has been reported for similar Niobrara Member pools. The difference between limestone and dolomite in susceptibility to fracturing is offered as an explanation for the fractures in the West Puerto Chiquito pool. This difference is related to differences in the crystal structures of calcite and dolomite, and consequently to the gliding m chanism of the two minerals, and their relative brittle or ductile behaviors in a common strain environment. The West Puerto Chiquito pool is considered commercially significant because of the unusual degree of inter-well communication through the fractured zones, as a few widely spaced wells are efficiently draining a reservoir of 25,000 acres or more. The hypothesis developed herein also may apply to Niobrara Member pools in northwestern New Mexico and the northwestern corner of Colorado which display many similarities to this pool.
Residual muscle contraction and prosthetic socket interface force in a transtibial amputee upon the osteomyoplastic procedure — A preliminary study

In the Transtibial Osteomyoplastic Amputation (TOA) technique, the fibular end and the tibial end are connected to each other by a bone bridge in order to stabilize the bony anatomy of the residual limb. In addition, during the myoplasty procedure, the ends of the muscles are secured to one another and to the bony foundations to re-establish the length-tension relationship. In contrast to conventional amputation techniques in which the muscles are cut and the length-tension relationship is lost overtime, the TOA procedure is anticipated to allow muscles to actively contract and return blood to the heart more efficiently [1]. In this study, the outcomes of the TOA procedure were investigated by measuring electromyography signals from the tibialis anterior and gastrocnemius muscles on the amputated leg as well as the interface force inside the prosthetic socket at the end-bearing level of a transtibial amputee. The subject had undergone the TOA procedure and the study was conducted while the subject walked on different terrain (level ground with different speeds, stairs, and incline) with two different kinds of prosthetic feet. Preliminary results showed that (1) the residual muscles appeared to be active while walking on various terrain, and (2) the activation level of the residual tibialis anterior muscle was found to be related to the force variation inside the prosthetic socket.
Organochlorine insecticide interactions affecting residue storage in rainbow trout

Three dose levels each of dieldrin (0 mg, 0.04 mg, 0.2 mg), DDT (0 mg, 0.2 mg, 1.0 mg), and methoxychlor (0 mg, 0.6 mg, 3.0 mg) were used in a 33 completely randomized factorial design. All 27 possible compound and dose combinations were used in the study. Six fish were used per treatment. The fish were individually given doses of insecticidesper os in corn oil enclosed in gelatin capsules. The fish were dosed on alternate days, seven doses in all. On the fifteenth day, the fish were killed and the fat body analyzed for lipid content and residual insecticides.
Computed Tomography in Meningitis

Computed tomography in 34 cases of meningitis has revealed a spectrum of findings. In acute cases these include enlargement of the subarachnoid spaces, generalized contrast enhancement of the meninges and ependyma, sterile and pyogenic subdural collections, cortical infarction, and cerebral necrosis.
Trends in adolescent bariatric surgery evaluated by UHC database collection

Background With increasing childhood obesity, adolescent bariatric surgery has been increasingly performed. We used a national database to analyze current trends in laparoscopic bariatric surgery in the adolescent population and related short-term outcomes.