cssi/SciSciGPT-SciSciNet huggingface dataset:
Workshop: Special problems in anticoagulation therapy: Cancer and venous thromboembolism-temporary discontinuation of warfarin for surgery and invasive procedures

Health care providers monitoring anticoagulated patients are often asked to make recommendations regarding anticoagulant management during periods when illness or treatment may complicate anticoagulant therapy. Two particularly difficult clinical problems concern the indications for and management of anticoagulant therapy in patients with cancer and the management of anticoagulated patients who must undergo some type of surgical procedure. Cancer is a significant risk factor for a variety of thromboembolic disorders, particularly venous thromboembolism. Venostasis from immobility, vessel wall damage from tumor invasion, and especially tumor-mediated activation of the coagulation system are important contributors to the prethrombotic state in cancer patients. The risk of venous thromboembolism is greatest during surgery, chemotherapy, and long-term use of central venous catheters. For selected patients, prophylaxis with subcutaneous heparin, low-intensity warfarin, or very low-intensity warfarin may substantially reduce this risk. A related concern for primary care clinicians is the increasing evidence that idiopathic venous thromboembolism may be the first manifestation of occult cancer. Whether and how these patients should be screened for malignancy is currently uncertain. Prior to surgical procedures in anticoagulated patients, clinicians must compare the risk of bleeding if anticoagulation is continued with the risk of recurrent thrombosis if anticoagulation is stopped. Bleeding risk is influenced by how a specific procedure affects the ability to assess and control bleeding and the intensity of anticoagulation at the time of the procedure. Thromboembolism risk is determined by the specific indication for the anticoagulation and the length of time during which anticoagulant therapy must be discontinued. Guidelines are suggested for perioperative anticoagulant management of patients with different thromboembolic disorders undergoing a variety of surgical procedures.
Postural control: toe-standing versus heel–toe standing

Toe-standing is observed in a number of populations who are able to stand without loss of balance and also those who have balance problems. Intuitively, individuals who stand on their toes are able to successfully regulate their whole body movement in order to keep themselves stable. Force platform data were collected for ten able-bodied subjects during three quiet standing postures, (a) heel-toe standing; (b) half-toe standing and (c) standing en demi pointe (full toe-standing). Differences in control mechanisms with each posture were compared using stabilogram diffusion analysis. During open-loop control (short-term), toe-standing is less stable than heel-toe standing (P<0.05). There is greater stochastic activity when toe-standing (P<0.05), suggesting that any short-term instability is being compensated for by an increase in muscle activity across the lower joints. During closed-loop control (long-term), there is no difference in mediolateral (ML) stochastic activity (increased activity has been linked to falls) between toe-standing and heel-toe standing. In addition, toe-standing is more stable than heel-toe standing (P< s0.05). Toe-standing, in and of itself, may not be responsible for balance problems in populations who compulsorily toe-stand.
Role of arginine residues in the structure and biological activity of botulinum neurotoxin types A and E.

Abstract When nicked types A and E as well as the unnicked (i.e., single chain) type E botulinum neurotoxins were treated with 1,2-cyclo-hexanedione, which specifically modifies the arginine residues in 0.2 M borate buffer, pH 8.0 i) both the nicked and unnicked neurotoxins were detoxified, ii) the unnicked single chain neurotoxin became resistant to nicking with trypsin, and iii) the serological reactivity of type A (type E was not tested) was altered. Reversal of the arginine modification partially restored toxicity. In the electroimmunodiffusion test the modified type A neurotoxin appeared as 2 cones; the height of one cone increased and the other decreased as the modification reaction progressed. These results indicate that i) at least one arginine residue is involved in maintaining the toxigenic structure of types A and E neurotoxins; ii) the site of nicking in type E is an arginyl bond; and iii) arginine residue is critical for at least one antigenic determinant of type A neurotoxin.
Survival and Developmental Disability in Infants With Birth Weights of 501 to 800 Grams, Born Between 1979 and 1994

Objective. Because the survival rate has increased for extremely low birth weight neonates, many have raised the concern that the rate of developmental disability among survivors will also increase. To address this concern, we analyzed changes over time in survival and major neurosensory impairment in a sample of extremely low birth weight infants born between July 1, 1979, and June 30, 1994. Methods. The study sample included 513 infants with birth weights of 501 to 800 g who were cared for in either of the two neonatal intensive care units that serve a 17-county region in northwest North Carolina and who were born to mothers residing in that region. At 1 year of age (corrected for gestation), survivors were examined by a pediatrician and were tested using the Bayley Scales of Infant Development. Major neurosensory impairment was defined as cerebral palsy, a Bayley Mental Developmental Index Results. Survival rates for epochs 1, 2, and 3 were, respectively, 24/120 (20%), 63/175 (36%), and 129/218 (59%). In contrast, the proportions with a major neurosensory impairment did not increase over time; rates for successive epochs were 6/24 (25%), 17/61 (28%), and 26/124 (21%). Rates of cerebral palsy were 3/24 (13%), 12/61 (20%), and 9/124 (7%); rates of delayed mental development were 4/24 (17%), 12/61 (20%), and 17/124 (14%); and rates of blindness were 2/24 (8%), 0/62, and 5/124 (4%), respectively. Conclusions. This analysis suggests that the increasing survival of extremely low birth weight neonates since the late 1970s has not resulted in an increased rate of major developmental problems identifiable at 1 year of age.
Aldolase Levels in Wild‐Type and Mutant Euglena gracilis

SYNOPSIS. Wild-type Euglena gracilis var. baciliaris, strains B and Z, synthesize 2 distinct fructose-1,6-diphosphate aldolases. Amounts of the 2 activities depend upon conditions of growth. The class I enzyme, with activity similar to that found in various photosynthetic tissues, is formed during regreening of dark-grown cultures incubated in the light. Very low activity of the class I enzyme is also found in mutant strains W3BUL and W8BHL, both of which apparently lack plastid DNA. The significance of these findings is discussed.
Strain energy density fracture criterion in elastodynamic mixed mode crack propagation

Abstract Sih's fracture criterion based on strain energy density, S , for mixed mode crack extension under static loading is extended to dynamic mixed mode, K I and K II , crack propagation. Influence of the second order term, σ ox , which represents the non-singular constant stress acting parallel to the direction of crack propagation, on the S distribution surrounding the crack tip, is demonstrated. Numerical studies show that positive σ ox enhances the fracture angle and negative σ ox reduces the fracture angle irrespective of the sign of K II / K I , when S is measured at a critical distance r c from the crack tip. This fracture criterion is verified by the crack curving results of dynamic photoelastic fracture specimens. Omission of σ ox term leads to predicted fracture angles which are at variance with experimental data.
Alternative Teacher Certification Programs and Texas Community Colleges

This chapter describes factors contributing to the successful planning and implementation of alternative teacher certification programs in one Texas community college district.
Surfing in Early Twentieth-Century Hawai'i: The Appropriation of a Transcendent Experience to Competitive American Sport

Surfing is an ancient Hawaiian sport that in its Hawaiian roots and style holds strongly to a transcendental nature. However, in the early twentieth century it underwent numerous changes which reduced its connections with traditional Hawaiian values and was appropriated by white or haole leaders as a marketing tool for the islands. This transfer of meaning through the experience of this long-cherished Hawaiian symbol of prowess altered the sport, leading to the development of modern surfing. In this paper, I will investigate the role that American cultural expressions such as film, the media and celebrities altered the meaning of the sport of surfing. While the act of surfing may bear similar resemblance today to the ‘royal sport’ of ancient Hawai‘i, the appropriation of the activity by American promoters drastically changed the essence of surfing and it developed into a modern competitive sport bereft of the richness it once held in the Kingdom of Hawai‘i.
System Call Anomaly Detection Using Multi-HMMs

This paper focuses on techniques to detect anomalous behavior in system call sequences. Since profiling complex sequential data is still an open problem in anomaly detection, there is a need to explore new approaches. While previous research has used Hidden Markov Models (HMMs) for anomaly-based intrusion detection, the proposed models tend to increase rapidly in complexity in order to increase the detection rate while reducing the false detections. In this paper, we propose a multi-HMMapproach applied for anomaly detection in clustered system call sequences. We run our experiments using the well-known system call data set provided by the University of New Mexico (UNM). Our process trace clustering approach using HMMs for system call anomaly detection provides accurate results and reduces the complexity required to detect anomalies. In this paper, we show how system call traces processed with our HMM method can provide a path forward to improved intrusion detection techniques.
BIFURCATION ANALYSIS OF LINE OF SIGHT VEHICLE GUIDANCE USING SLIDING MODES

The problem of dynamic loss of stability during line-of-sight pursuit navigation of a vehicle under automatic control of a heading sliding mode autopilot is considered. The linear and nonlinear controller gains and the lookahead distance of the guidance law are the main bifurcation parameters. Hopf bifurcation theory techniques are used in order to establish stability of the resulting periodic solutions after the initial loss of stability of straightline motion. The analytical results are confirmed by numerical integrations. It is shown that both linear and nonlinear methods are required in order to evaluate the dynamic response of the system.
Writing Post-Orientalist Histories of the Third World: Perspectives from Indian Historiography

To ask how the “third world writes its own history” appears, at first glance, to be exceedingly naive. At best, it reaffirms the East–West and Orient–Occident oppositions that have shaped historical writings and seems to be a simple-minded gesture of solidarity. Furthermore, in apparently privileging the writings of historians with third-world origins, this formulation renders such scholars into “native informants” whose discourse is opened up for further disquisitions on how “they” think of “their” history. In short, the notion of the third world writing its own history seems to reek of essentialism. Seen in another way, this formulation can be construed as positing that the third world has a fixed space of its own from which it can speak in a sovereign voice. For many, this notion of a separate terrain is rendered problematic by the increasing rapidity and the voracious appetite with which the postmodern culture imperializes and devours spaces.
A distributed caching algorithm for streaming uncompressed HD video

This poster introduces a new distributed caching algorithm used by the installable Celerra MPFS file system client to allow streaming high throughput High-Definition video streams. Large disk latencies in high throughput streaming result in a high video frame drop rate. Dropped frames rate increases with the video throughput. The algorithm proposed in this paper uses new caching ideas inspired by signal processing techniques to address dropped frames. Our techniques remove the dropped frames effect entirely, while optimizing the aggregate throughput of the storage array.
Ultrasonic investigation of the glass transition in glycerol

We have measured, as a function of temperature and frequency, the velocity and attenuation of ultrasound near the glass transition of glycerol. The data are compared with that from frequency-dependent specific-heat measurements recently performed on the same sample. When the difference between adiabatic and isothermal processes is taken into account, we find that the relaxation time associated with the ultrasonic measurements is the same as that responsible for the dispersion seen in the specific-heat experiment. We also compare our results with recent hydrodynamic theories of the glass transition. The relaxation time that we measure can be fitted equally well either by a scaling form \ensuremath{\tau}=${\ensuremath{\tau}}_{0}$[(T-${T}_{h}$)/${T}_{h}$${]}^{\mathrm{\ensuremath{-}}\ensuremath{\alpha}}$, as these theories predict, or by the Vogel-Tamman-Fulcher law \ensuremath{\tau}=${\ensuremath{\tau}}_{0}$exp[E/${k}_{B}$(T-${T}_{0}$)], which has often been used to fit relaxation behavior in glasses. In the scaling-law fit, \ensuremath{\alpha}=12.5, which is unexpectedly large. The recent theory of Marchetti, which includes the wave-vector dependence of the mode-coupling vertex, provides a good fit to the frequency dependence of the data at constant temperature.
Pastor and Lay Leader Perceptions of Barriers and Supports to HIV Ministry Maintenance in an African American Church

Clergy and lay leaders have a pivotal role in the development and maintenance of HIV Ministries within the African American church. However, little is known about the actual roles these men and women have, the barriers they face and the supports they have found in the development and maintenance of an HIV Ministry. The purpose of this study is to examine the role, barriers and supports clergy and lay leaders experienced in the development of a long-standing HIV ministry in an African American church. These data were gathered from a larger ethnographic study, which examined the role of religious culture in the development, implementation and maintenance of an HIV ministry. Data for this study were collected through in-depth semi-structured interviews. Results revealed that the primary role of clergy and lay leaders involved dispelling myths surrounding HIV and ensuring congregational support. The primary barrier to the development and maintenance was views regarding sexuality. The primary support was their relationships with congregants that lived with HIV and AIDS. This information can assist in developing interventions to enhance the African American church movement toward HIV ministries.
A multiple-objective optimal exploration strategy

Exploration for natural resources is accomplished through partial sampling of extensive domains. Such imperfect knowledge is subject to sampling error. Complex systems of equations resulting from modelling based on the theory of correlated random fields are reduced to simple analytical expressions providing global indices of estimation variance. The indices are utilized by multiple objective decision criteria to find the best sampling strategies. The approach is not limited by geometric nature of the sampling, covers a wide range in spatial continuity and leads to a step-by-step procedure.
Spatial expression of a mercury-inducible green fluorescent protein within a nanoporous latex-based biosensor coating

Optimizing the reactivity of cell coatings developed as biosensors or biocatalysts requires measurements of gene expression in the immobilized cells. To quantify and localize gene expression within a latex-based mercury biosensor, a plasmid, pmerGFP, was constructed, which contains the green fluorescent protein (GFP) gene under transcriptional control of the mercury resistance operon regulatory sequences. When cells containing this plasmid were exposed to mercuric chloride, GFP synthesis was induced and could be quantified by fluorescence. E. coli strain JM109 (pmerGFP) was mixed with SF091 latex (Rohm & Haas), Tween 20, and glycerol, and coated as an approximate 20-μm thick nanoporous adhesive coating on a polyester substrate. The cell coat was overlaid with a nanoporous topcoat of latex, Tween 20, and glycerol. Different fluorescent microspheres were used to mark the topcoat and cell coat layers of the coating. Upon exposure to mercury(II), cells within the coating were induced to synthesize GFP, and laser scanning confocal microscopy was used to quantify expression spatially within the cell coat. GFP expression in the coatings increased with increasing mercury concentration (2–20 μM), temperature (21–37 °C), and time of incubation (0–39 h). There was a gradient of GFP expression through the cell coat with expression higher near the topcoat–cell coat interface relative to the bottom of the cell coat. The topcoat thickness did not significantly affect GFP expression indicating that diffusion of mercury(II) and oxygen through the topcoat was not limiting.
A SELF-STABILIZING DISTRIBUTED ALGORITHM TO CONSTRUCT BFS SPANNING TREES OF A SYMMETRIC GRAPH

We propose a simple and efficient self-stabilizing distributed algorithm to construct the breadth first search (BFS) spanning tree of an arbitrary connected symmetric graph. We develop a completely new direct approach of graph theoretical reasoning to prove the correctness of our algorithm. The approach seems to have potential to have applications in proving correctness of other self-stabilizing algorithms for graph theoretical problems.
Mutagenesis of the C2 domain of protein kinase C-alpha. Differential roles of Ca2+ ligands and membrane binding residues

The C2 domains of conventional protein kinase C (PKC) have been implicated in their Ca2+-dependent membrane binding. The C2 domain of PKC-alpha contains several Ca2+ ligands that bind multiple Ca2+ ions and other putative membrane binding residues. To understand the roles of individual Ca2+ ligands and protein-bound Ca2+ ions in the membrane binding and activation of PKC-alpha, we mutated five putative Ca2+ ligands (D187N, D193N, D246N, D248N, and D254N) and measured the effects of mutations on vesicle binding, enzyme activity, and monolayer penetration of PKC-alpha. Altered properties of these mutants indicate that individual Ca2+ ions and their ligands have different roles in the membrane binding and activation of PKC-alpha. The binding of Ca2+ to Asp187, Asp193, and Asp246 of PKC-alpha is important for the initial binding of protein to membrane surfaces. On the other hand, the binding of another Ca2+ to Asp187, Asp246, Asp248, and Asp254 induces the conformational change of PKC-alpha, which in turn triggers its membrane penetration and activation. Among these Ca2+ ligands, Asp246 was shown to be most essential for both membrane binding and activation of PKC-alpha, presumably due to its coordination to multiple Ca2+ ions. Furthermore, to identify the residues in the C2 domain that are involved in membrane binding of PKC-alpha, we mutated four putative membrane binding residues (Trp245, Trp247, Arg249, and Arg252). Membrane binding and enzymatic properties of two double-site mutants (W245A/W247A and R249A/R252A) indicate that Arg249 and Arg252 are involved in electrostatic interactions of PKC-alpha with anionic membranes, whereas Trp245 and Trp247 participate in its penetration into membranes and resulting hydrophobic interactions. Taken together, these studies provide the first experimental evidence for the role of C2 domain of conventional PKC as a membrane docking unit as well as a module that triggers conformational changes to activate the protein.
Ordered priority queues

A new data structure called ordered priority queue is introduced in this paper. Elements stored in the data structure have a primary order (key) and a secondary order (priority) associated with them. An ordered min-priority queue allows users to find the minimum priority element in any range (according to key order) inO(logn) time. Such a data structure withn elements can be created inO(n logn) time usingO(n) storage. A specific implementation based on median split trees is presented. Sequential access of the elements can be done inO(n log logn) time andO(logn) extra storage.
Additional effects of monovalent cations on the lysine-sensitive aspartokinase of E. coli B

The apparent specificity of activation of lysine-sensitive aspartokinase (E.C.2.7.2.4) from E. coli by monovalent cations differs depending on the assay used and on the Mg2+ concentration. Activity is nearly absolutely dependent on and is highly specific for a monovalent cation in the aspartate semialdehyde dehydrogenase coupled assay or the adenosine triphosphate-adenosine diphosphate exchange assay. Little specificity for monovalent cations is observed using the aspartyl hydroxamate assay. Activation and specificity are also altered by Mg2+ concentrations at a constant 5 mM nucleotide concentration. At a low ( 1.25 or 1.6 mM) Mg2+ concentration, monovalent cation activation and specificity are nearly absolute. Less dependence on monovalent cations and less specificity are observed at a higher Mg2+ concentration (6 mM). Li+ inhibits aspartokinase competitively with respect to either K+ or NH4+. Monovalent cations are also thermoprotective and differential thermal inactivation experiments at 56°C reveal that NH4+ and K+, either of which will produce maximum catalytic activity, interact differently with aspartokinase. K+ interacts with positive cooperativity, whereas NH4+ does not. K+, NH4+, and Na+ are about equally effective in enhancing the dissociation of the aspartokinase-aspartylphosphate complex. Li+ is less effective.
Dissection of endoplasmic reticulum stress signaling in alcoholic and non-alcoholic liver injury

Accumulation of unfolded or malfolded proteins induces endoplasmic reticulum (ER) stress which elicits a complex network of interacting and parallel responses that dampen the stress. The ER stress response in the liver is controlled by intrinsic feedback effectors and is initially protective. However, delayed or insufficient responses or interplay with mitochondrial dysfunction may turn physiological mechanisms into pathological consequences including apoptosis, fat accumulation and inflammation all of which have an important role in the pathogenesis of liver disorders such as genetic mutations, viral hepatitis, insulin resistance, ischemia/reperfusion injury, and alcoholic and non-alcoholic steatosis. In both alcohol and non-alcohol-induced ER stress, a common candidate is hyperhomocysteinemia. Betaine supplementation and/or expression of betaine-homocysteine methyltransferase (BHMT) promote removal of homocysteine and alleviate ER stress, fatty accumulation and apoptosis in cultured hepatocytes and mouse models. The rapidity and magnitude of homocysteine-induced activation of each of the main ER resident transmembrane sensors including inositol requiring enzyme 1 (IRE-l alpha), activating transcription factor 6 (ATF-6) and RNA-activated protein kinase (PKR)-like ER kinase (PERK) appear different in different experimental models. Dissection and differentiation of ER stress signaling may reveal clues on the specific importance of the ER stress response in contributing to liver injury and thus provide better strategies on prevention and treatment of liver disease.
Inhibition of Adrenal Corticosteroidogenesis in the Rat by Cyanotrimethylandrostenolone, a Synthetic Androstane

The administration of the synthetic androstane, 2α-cyano-4,4,17α-trimethyl- 17β-hydroxy-5-androsten-3-one (CTA, cyanoketone) to rats at a level of 4 mg daily for 7 days induced adrenal hypertrophy and reduced adrenal venous corticosterone secretion 5-fold (from 4.3 to 0.8 μg/100 g body wt/10 min). Incubation of adrenal homogenate from CTAtreated rats with NADPH or G-6-P+NADP, was found to result in a 30–90% reduction in the ability to convert exogenously added pregnenolone into 11-deoxycorticosterone (DOC). The adrenal homogenate from the cyano-ketone treated rats showed no reduction in ability to 21-hydroxylate progesterone or 11β-hydroxylate DOC. If anything, the hydroxylation of DOC was enhanced. Similar results were found when the cyano-ketone was added to adrenal homogenate from normal rats. At levels of 0.8 μM or higher, the cyano-ketone completely prevented the conversion of exogenous pregnenolone into blue tetrazolium (BT) positive corticoid products in the presence of NADPH. The concentrations of...
CDBG in Chicago: The Politics of Control

The first eight years of CDBG provided Chicago with almost three-quarters of a billion dollars. At the outset, the city executive, headed by Mayor Richard J. Daley, took control of CDBG planning and allocation, despite the efforts of the "machine's" opponents to use CDBG's housing assistance and citizen participation requirements as levers for political reform and social change. The city executive continued infirm control even after the Carter administration took office determined to reverse inherited New Federalism policies. City hall opponents found that HUD's more assertive policies on housing assistance, citizen participation, and targeting had little effect on the executive's ability to decide how and where to spend CDBG funds. The dominant role of the executive also persisted after Mayor Daley's death, although Mayor Jane Byrne (elected in 1979) shifted CDBG decisionmaking from operating city departments to the mayor's budget office.
Facilitated discrimination learning as effected by response-contingent neutral and aversive stimuli

Abstract To assess the cue interpretation of the shock-right (SR) facilitation phenomenon, rats received visual discrimination training in which, for different groups, neutral and aversive intensities of white noise were presented selectively contingent on either right or wrong responses or nonselectively contingent on both responses. The nonselective (yoked) contingency groups did not differ from a no-noise control group at any of the noise intensities tested. In contrast, the selective contingency (noise-right and noise-wrong) groups showed comparably facilitated performance which was a positive S-shaped function of noise intensity. These findings cast doubt on an “alerting” or “sensitizing” function of the stimulus and indicate instead that, when selectively applied to a response, the stimulus effectively operates as a distinctive cue to increase the discriminability of the alternatives and thereby facilitate performance. That such facilitation obtains with a neutral as well as an aversive stimulus and relates, in accord with the Weber function, to the intensity characteristics of the stimulus argues strongly that the SR phenomenon is appropriately viewed as a stimulus-right effect.
Partnered Research in Healthcare Delivery Redesign for High-Need, High-Cost Patients: Development and Feasibility of an Intensive Management Patient-Aligned Care Team (ImPACT)

OBJECTIVES We employed a partnered research healthcare delivery redesign process to improve care for high-need, high-cost (HNHC) patients within the Veterans Affairs (VA) healthcare system.
Long-term response to artificial selection with multiple alleles—Study by simulations

Abstract The effect of multiple alleles on long-term response to selection is examined by simulations using a pseudosampling technique to simulate the multidimensional diffusion process. The effects of alleles are independently drawn from a normal distribution and the initial frequencies of alleles are assumed either to be equal or to be drawn from a neutral equilibrium population. With these two initial gene frequency distributions we examined various properties of the selection response process for the effects of number of alleles and selection intensity. For neutral initial frequencies the effects of multiple alleles compared with two alleles are minor on the ratio of final to initial response ( E (R ∞ ) E (R 1 )) and the half life of response ( t 0.5 ), but are significant on the variance of response. Under certain conditions the variance of the selection limit can even increase as selection gets stronger. For equal initial frequencies the effects of multiple alleles are, however, minor on the ratio of the variance of the selection limit to the initial genetic variance, but ( E (R ∞ ) E (R 1 )) and t 0.5 increase as the number of alleles increases. The results show that for certain statistics the effects of multiple alleles can be minimized by an appropriate transformation of parameters for given initial gene frequencies, but the effects cannot, in general, be removed by any single transformation or reparameterization of parameters.
A High Power U. H. F. Diode Phase-Shifter

The electronically-scanned antenna, for which this phase-shifter was designed, requires the ability to switch the sense of circular polarization radiated or received by each antenna element. This necessary feature, together with the ability to control each antenna element phase in steps of 45-degrees, is provided by one microwave assembly, shown in Figure 1.
Smoking is associated with an increased risk of acute chest syndrome and pain among adults with sickle cell disease.

To the editor: Acute chest syndrome (ACS) is a leading cause of hospitalization and death for people with sickle cell disease (SCD).[1][1] Cigarette smoking has been inconsistently related to an increased risk of ACS in prior studies[2][2],[3][3] and may be one of the few potentially modifiable
Defense acquisition system simulation studies

A systems engineering process model for the acquisition of large, complex systems for the U.S. Department of Defense (DoD) is being adapted for ongoing experiments in acquisition process policies. The discrete-event simulation model of the larger "enterprise of acquisition" for weapon systems has a broad scope from program beginning through development. It reveals some of the challenges and risks in weapon system acquisition.Initially the model was used to evaluate potential policies as interventions and/or system changes in an Air Force context. The simulation results showed varying degrees of influence on program outcomes and suggested no single antidote exists for solving acquisition problems. Many of the negative outcomes reflected through cost and schedule overruns are due to the behavior of the acquisition system itself.A collaboration between the Air Force Institute of Technology (AFIT), the Naval Postgraduate School (NPS), and The Aerospace Corporation is underway to translate the model and adapt it for new considerations. Shortly we will propagate new model versions and results to the public, and use it for additional Air Force and Navy programs of concern.
Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables

The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.
Monte Carlo algorithm for a two-dimensional Hubbard model of High-Tc superconductivity

A Monte-Carlo procedure is given for the two-dimensional (2-D) Hubbard model using the Suzuki-Trotter transformation. The resulting three-dimensional (3-D) classical model does not have the usual problems with negative transition probabilities in the large-U limit (U-repulsive interactions). Numerical simulations based on the algorithm described are expected to be of importance for the theory of high-T c superconductivity.
Restoration of firearm serial numbers with electron backscatter diffraction (EBSD)

Abstract Firearm serial numbers are a critical identifying mark, and restoration of destroyed serial numbers is often crucial for prosecution of a criminal case. A method is presented utilizing electron backscatter diffraction (EBSD) in the scanning electron microscope (SEM) which allows for clear visualization of die-stamped imprints which have been completely polished away. Evidence of the stamp can be observed to a depth of approximately 760μm below the surface. With further development, the described method is capable of reconstructing an 8 character serial number in approximately 1h.
Study of the nitrogen response mode of the thermionic rubidium silicate detector

Abstract The thermionic nitrogen detector has been found to be a concentration-sensitive detector. Bead current vs. heating current curves are continuously shifted toward higher heating currents and bead life may be as short as two months. The bead current and sensitivity are strongly dependent on carrier gas, hydrogen, and air flow-rates. The optimum bead current compatible with minimal bead aging is 10–30 pA. Sensitivity changes obtained by increasing bead current due to increasing hydrogen flow-rates are larger than corresponding changes obtained by electrical heating. Optimum signal-to-noise ratios were obtained at a hydrogen flow-rate of 2–4 ml/min and an air flow-rate of 60–70 ml/min.
Large-volume sample introduction into narrow-bore gas chromatography columns using thermal desorption modulation and signal averaging

A small diameter (50 μm) open-tubular gas chromatographic column can be made to accept relatively large volume samples. A conventional injection port and a short length of a 530-μm-diameter column are used to accept and hold the sample while it is fed slowly into the 50-μm column. An injection of such large volume and slow speed normally is quite incompatible with this small, fast column. An on-column thermal desorption modulator at the head of the column matches the sample to the column by chopping the injected sample into many fast concentration pulses. Signal averaging of the resulting fast chromatograms gives a total sample chromatogram. The method is adaptable to either gaseous or liquid samples.
Integrated simulation model for preliminary aerodynamic, structural, and control-law design of aircraft

An integrated model is developed for aerodynamic, structural, and control simulation of flexible aircraft in extreme flight situations. The structure consists of joined nonlinear beams allowing arbitrarily large deformations. The aerodynamic model is a compressible vortex/source-lattice with wind-aligned trailing vorticity. Full unsteady terms with flight dynamics are included. Model forcing is via gusts or control inputs. The overall nonlinear equation set is solved by a full Newton method. The Newton Jacobian matrix is also used for frequency-domain computations to investigate flight stability, control-response behavior, and flutter. Nonlinear performance of control laws can be examined. The numerical problem is small enough for interactive computation, allowing rapid diagnosis of local aerodynamic stall, structural failure, or control system saturation for a wide range of flight conditions. The overall approach allows quick generation of a robust multi-disciplinary preliminary design which can serve as a good basis for subsequent detailed design.
Rain forest establishment and succession in the Hawaiian Islands

Abstract Processes of biological invasion, establishment and succession of tropical rain forest vegetation in the biogeographically remote insular environments of Hawaii are reviewed with reference to similarities in the ecology of post-mining landscapes. New cinder cones in volcanically active areas are completely abiotic deposits like mine spoils. Colonization can be slower than on other volcanic deposits in the same area because of fewer favorable microhabitats. Also the rate of invasion may suddenly increase if a native dispersal agent reappears in the recovery process. Over longer time spans the successional pathways converge, overriding the initial substrate differences. From Hawaii’s naturally impoverished, native biodiversity, a simple monodominant rain forest emerges, which is dominated by a pioneer tree species, Metrosideros polymorpha (Myrtaceae). This species appears as the first tree on raw volcanic substrates and maintains its dominant canopy position by a growth cycle involving canopy dieback. It, thereby, creates secondary successions favorable for its own regeneration as a shade-intolerant pioneer tree. A long-term succession model shows progressive development terminating in a plant biomass and biophilic nutrient climax. This climax may last for thousands of years to be followed eventually by a regressive phase. In this phase, the monodominant forest recovers with decreasing stature and biomass due to nutrient depletion. An independent soil genesis model supports this trend, which ends in the formation of nutrient exhausted volcanic soils with accumulated gibbsite in ferruginous bauxite. Metrosideros and an aluminum absorbing fern, Dicranopteris linearis , still grow on these nutrient depleted bauxite enriched soils. But when these are strip-mined to saprolite surfaces, only hardy introduced species are capable of reinvasion. The native spectrum of colonizer species appears not broad enough to cope with such new and artificially exposed surfaces. Similar relationships may limit natural recovery of mine-spoils in other regions, thereby requiring costly amendments for rehabilitation.
Characterization of desmoglein expression in the normal prostatic gland. Desmoglein 2 is an independent prognostic factor for aggressive prostate cancer.

Purpose The expression of desmogleins (DSGs), which are known to be crucial for establishing and maintaining the cell-cell adhesion required for tissue integrity, has been well characterized in the epidermis and hair follicle; however, their expression in other epithelial tissues such as prostate is poorly understood. Although downregulation of classical cadherins, such as E-cadherin, has been described in prostate cancer tissue samples, the expression of desmogleins has only been previously reported in prostate cancer cell lines. In this study we characterized desmoglein expression in normal prostate tissues, and further investigated whether Desmoglein 2 (DSG2) expression specifically can serve as a potential clinical prognostic factor for patients diagnosed with primary prostate cancer. Experimental Design We utilized immunofluorescence to examine DSG2 expression in normal prostate (n = 50) and in a clinically well-characterized cohort of prostate cancer patients (n = 414). Correlation of DSG2 expression with clinico-pathological characteristics and biochemical recurrence was analyzed to assess its clinical significance. Results These studies revealed that DSG2 and DSG4 were specifically expressed in prostatic luminal cells, whereas basal cells lack their expression. In contrast, DSG1 and DSG3 were not expressed in normal prostate epithelium. Further analyses of DSG2 expression in prostate cancer revealed that reduced levels of this biomarker were a significant independent marker of poor clinical outcome. Conclusion Here we report for the first time that a low DSG2 expression phenotype is a useful prognostic biomarker of tumor aggressiveness and may serve as an aid in identifying patients with clinically significant prostate cancer.
Testing for Differences between two brands of Cookies

Summary This article presents two class activities for use with hypothesis testing. The first has students collecting data to test for a difference in the mean number of chocolate chips per cookie between two brands. Data are also collected to test for a difference in taste ratings.
Marriage amendments and psychological distress in lesbian, gay, and bisexual (LGB) adults.

An online survey of lesbian, gay, and bisexual (LGB) adults (N = 1,552) examined minority stress (I. H. Meyer, 2003) and psychological distress following the 2006 general election in which constitutional amendments to limit marriage to 1 man and 1 woman were on the ballot in 9 states. Following the November election, participants living in states that passed a marriage amendment reported significantly more minority stress (i.e., exposure to negative media messages and negative conversations, negative amendment-related affect, and LGB activism) and higher levels of psychological distress (negative affect, stress, and depressive symptoms) than participants living in the other states. Multiple hierarchical regression analyses revealed significant positive main effects of minority stress factors and state ballot status on psychological distress. In addition, the association between amendment-related affect and psychological distress was significantly higher in states that had passed a marriage amendment compared with other states. Discussion of these findings emphasizes that marriage amendments create an environment associated with negative psychological outcomes for LGB individuals.
Monolithic millimeter-wave two-dimensional horn imaging arrays

A monolithic two-dimensional horn imaging array has been fabricated for millimeter wavelengths. In this configuration, a dipole is suspended in an etched pyramidal cavity on a 1- mu m silicon-oxynitride membrane. This approach leaves room for low-frequency connections and processing electronics. The theoretical pattern is calculated by approximating the horn structure by a cascade of rectangular-waveguide sections. The boundary conditions are matched at each of the waveguide sections and at the aperture of the horn. Patterns at 93 and 242 GHz agree well with theory. Horn aperture efficiencies of 44+or-4%, including mismatch and resistive losses, have been measured. A detailed breakdown of the losses is presented. The coupling efficiency to various f-number imaging systems is investigated, and a coupling efficiency of 24% for an f0.7 imaging system (including spillover, taper, mismatch and resistive losses) has been measured. Possible application areas include imaging arrays for remote sensing, plasma diagnostics, radiometry and superconducting tunnel-junction receivers for radio astronomy. >
The relationship between affective and normative commitment: review and research agenda

Meyer and Allen's (1991, 1997) three component conceptualization of organizational commitment (OC) includes affective (AC), continuance (CC), and normative (NC) commitment. However, AC and NC have not been as empirically differentiated as theoretically expected. Drawing on the extant literature, I review, integrate, and expand on arguments and evidence about the lack of AC-NC differentiation. I also propose several avenues for research that could help commitment scholars attain a clearer picture of the true relationship between AC and NC, as the extant literature has inadequately addressed many issues regarding construct differentiation. Specific, testable propositions address a variety of facets of the commitment literature, including construct definition and measurement, developmental processes, relationships among the components and their unique and joint effects on outcomes, and potential moderators of the AC-NC relationship. The goal of this paper is to spur future research into the AC-NC relationship in order to gain greater construct clarity. Copyright © 2006 John Wiley & Sons, Ltd.
Acts of perceptual inquiry: problems for any stimulus-based simplicity theory.

Stimulus-specified simplicity is simply insufficient to predict the appearance of objects' 3D forms and figural shapes, etc., as originally intended. Which information a viewer chooses to attend can determine both what 3D structure is perceived and its attendant perceptual consequences; moreover, a shape's meaningfulness or denotivity [M.A. Peterson, Current Directions in Psychological Science 3 (1994) 105] can overcome simplicity-based figure-ground segregation. In both cases, perceptual consequences, such as subsequent perceived movements, are constrained or primed in ways that can help us corroborate and define what the viewer has perceived; that may help us in studying the underlying events in brain processing; and that should help in designing such perceptual applications as still and animated displays. Demonstrations, theoretical framework, and potential research tools are offered.
Vascular injuries associated with elective orthopedic procedures.

The objective of this study was to review the diagnosis, management, and outcome of the rare iatrogenic arterial injury associated with elective orthopedic joint procedures. A retrospective review was conducted of all patients presenting to the vascular surgery service with arterial injury after elective orthopedic procedures between 1997 and 2002. Clinical records were reviewed for presentation, type of injury, management, and outcome. During the study period, 20 patients having 21 total orthopedic procedures were identified with 27 arterial injuries. There were 4350 elective orthopedic procedures during this period for an incidence of 0.005%. There were 14 total knee arthroplasties, 4 total hip arthroplasties, and 3 ankle reconstructions in the study group. Presenting signs included acute ischemia with loss-of-limb Doppler-detected arterial flow/pulses (13 patients, 62%), intraoperative arterial bleeding (3 patients, 14%), nonhealing wounds (3 patients, 14%), and limb edema (2 patients, 10%); the diagnosis was delayed >24 hr in 5 patients (25%). Arterial thrombosis was the most common abnormality identified (21 of 27 injuries, 78%), followed by laceration/avulsion (3 injuries, 11%) and pseudoaneurysm development (3 patients, 11%), and involved the iliac (n = 3), common femoral (n = 2), profunda (n = 1), superficial femoral (n = 4), popliteal (n = 12), or tibial (n = 5) arteries. Concomitant popliteal venous injury was present in one patient. Injured arterial segments had preexisting atherosclerotic disease (33%) and 15 patients (71%) had prior surgery in proximity to the arterial injury while an additional 9 (43%) had prior traumatic injury (7 [78%] of whom had revision orthopedic surgery as well). Management consisted of vein bypass grafting (n = 15, 56%), primary repair (n = 3, 11%), and thrombectomy with thrombolysis (n = 2, 7%). One patient (5%) underwent primary above-knee amputation. There was one death from septic shock and there were three limb losses (14%). Arterial injury associated with elective orthopedic joint surgery is more common during redoprocedures and in patients with preexisting atherosclerosis. Despite arterial repair/bypass, limb morbidity is common and related to preexisting occlusive disease or extent of arterial thrombosis.