cssi/SciSciGPT-SciSciNet huggingface dataset:
Added Value of Digital over Analog PET: A Technologist Perspective

2006 Objectives: The capabilities of the digital PET/CT system from the analog PET/CT system have dramatically changed the environment in which technologists work. Advances in photon detection have led to better resolution, quantification, dose reduction, and decreased scan times. Advances in CT allow for additional reconstructions that were not capable on the analog system. The digital system also requires less downtime from 3 day to 1 due to the use of Digital Photon Counting technology which is less sensitive to temperature variations. These improvements have profoundly affected daily operations, patient scheduling, and radiation exposure to both the patient and technologists. We set out to compare these differences in the two technologies at our institution. Materials and Methods: A total of 109 patients undergoing a standard of care F-18 FDG PET/CT exam on a digital TOF scanner who also had a prior exam on the analog TOF scanner were included in our study. A log was created to compare the F-18 FDG dose, PET scan time, and CT dose index (CTDI) between the two scanners. Results: When comparing 109 patients scanned on both the analog TOF PET/CT vs digital TOF PET/CT, our preliminary data (Table 1) has shown an average reduced scan time from 24.92 minutes to 16.68 minutes (33%), an F-18 FDG dose reduction from 10.94 to 9.46 (14%), and a decrease in CTDI from 3.75 to 2.03 (46%). Due to the reduction in scan times, technologists are able to schedule patients more efficiently, have more flexibility with patient arrival times, add-ons, patient preparation, and provide overall better care. Although we saw a 14% FDG dose reduction in these patients, the potential is even greater with obese patients since the maximum FDG dose with the digital scanner is 10 mCi versus 15 mCi with the analog scanner. Overall the dose reduction also lead to a reduction in the radiation exposure to the technologist (data collection is still in progress). Conclusions: Ongoing data collection comparing analog TOF PET/CT and digital TOF PET/CT scanners continues to be acquired. However, our initial assessment since the implementation of the digital TOF scanner has shown the ability to increase productivity while reducing scan time, reducing patient and technologist radiation exposure while improving image quality. Table 1. Comparison of Analog TOF PET vs. Digital TOF PET
Popper’s Experiment

From the point of view of classical theory and our everyday experience, quantum phenomena are surprising and the concepts of quantum mechanics are incomprehensible. Since the beginning of quantum theory, scientists questioned its very basic concepts and proposed gedankenexperiments, or thought experiments, to probe its foundations. In 1934, one year before the 1935 paper of Einstein–Podolsky–Rosen, Popper published a thought experiment based on his philosophy of realism. In this chapter we review two experimental realizations of Popper’s thought experiment. On one hand, the experimental observations confirm the predictions of Popper. On the other hand, quantum theory agrees with the experimental data perfectly. The experimental observations do not lead to any “violations” of the principles of quantum mechanics. One important conclusion we may draw from the two experiments is that the observations are the results of multi-photon interference: a pair of photons interferes with the pair itself at distance. The nonlocal multi-photon interference phenomena may never be understood in classical theory, however, it is legitimate in quantum mechanics. The superposition principle of quantum theory supports multi-photon interference, whether the photons are entangled or randomly paired, despite the distances between these individual photodetection events.
Categorical Confusion: Ideological Labels in China

The idea of a left-right ideological dimension helps citizens and parties organize their thinking about politics. While the left-right dimension is traditionally organized around questions of inequality and change in democracies, its meaning under authoritarian rule remains uncertain. This paper uses two national surveys to investigate the policy, partisan, and symbolic content of the left-right dimension in China. The analysis of these surveys reveals that while many Chinese citizens are willing to locate themselves on the left-right scale, their placements are distorted by a variety of perceptual bias known as differential item functioning. The labels of left and right do not carry a consistent programmatic meaning, and the partisan and symbolic content of these ideological labels is limited. One implication of the absence of a shared ideological understanding is that it prevents Chinese citizens from developing the type of vocabulary necessary for exercising political agency.
Design and modeling of a planar graphene structure as a terahertz cyclotron radiation source.

With incredibly high carrier mobility and saturation velocity, graphene would be an ideal candidate for a miniaturized solid-state cyclotron radiation source. A planar semicircular graphene arc geometry was investigated for emission in the 0.5–1.5 THz range. Analytical studies, confirmed by finite element simulations, show that the emitted THz frequencies are inversely proportional to the arc radius given a fixed charge-carrier velocity. The simulations show that the desired frequency spectrum can be obtained with design radii ranging from 50 to 150 nm. Interestingly, the radiated spectrum is independent of the frequency of the stimulation of the graphene nano-arcs. The simulations also indicate that the total output power correlates well with the Larmor formulation. The device is expected to emit 1 nW/cm2, which confirms the findings of existing research in this field. Such a design could yield a scalable and cost-effective THz source.
Uniqueness of Bipartite Factors in Prime Factorizations Over the Direct Product of Graphs

iv 1 Preliminaries 1 2 Graph Products 4 2.1 The Direct Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 The Cartesian Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3 The Cartesian Skeleton 10 4 Main Result 14 Bibliography 28 Vita 29
Healthcare and Business

Business and healthcare are two terms we hear almost every day, but rarely do we hear them together. Healthcare is the prevention, maintenance, or restoration of a person’s health by trained medical specialists and medical institutions. Business is when a type of person or corporation of some sort sells goods or services in an effort to make a profit. Business and healthcare should be used together since one cannot survive without the other. A healthcare service must be treated like a business and make a profit so that it can pay its employees and vendors, while sustaining growth for an economically viable life. Healthcare has changed over time from a business where there is an excess of cash available to a business with increased regulation and governance, increased costs, and reduced cash flow. Managed care, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), state and federal regulations, the Centers for Medicare and Medicaid Services (CMS), the Patient Protection and Affordable Care Act (PPACA) or (ACA), the Health Insurance Portability and Accountability Act (HIPAA) of 1996, the Health Information Technology for Economic and Clinical Health (HITECH), accountable care, and many other factors make the healthcare business one of complexity and confusion. Our complex healthcare world demands that physician and nonphysician leaders develop an understanding of the business aspect of healthcare. These changes in healthcare have also caused alterations in healthcare leadership positions. Many physicians have been called upon to be leaders of healthcare organizations, and this trend is likely to continue as more and more physicians are becoming employees of healthcare systems. Many of today’s leaders are experts at either the healthcare field or business, but not always both. This can be financially detrimental to a healthcare business. The chapters in this book are intended to assist in the education of healthcare leaders, including both physicians and nonphysician administrators, in the tools of the healthcare business trade. These tools will apply to both the for-profit side and not-for-profit side of healthcare. Not-for-profit businesses still need to make a “profit.”
Morphing the Hugin and Shenoy–Shafer Architectures

The Hugin and Shenoy–Shafer architectures are two variations on the jointree algorithm, which exhibit different tradeoffs with respect to efficiency and query answering power. The Hugin architecture is more time–efficient on arbitrary jointrees, avoiding some redundant computations performed by the Shenoy–Shafer architecture. This efficiency, however, comes at the price of limiting the number of queries the Hugin architecture is capable of answering. In this paper, we present a simple algorithm which retains the efficiency of the Hugin architecture and enjoys the query answering power of the Shenoy–Shafer architecture.
Electrical property studies of oxygen in Czochralski-grown neutron-transmutation-doped silicon

Electrically active oxygen-related donors can be formed in Czochralski (Cz) Si either during crystal growth or during subsequent heat treatment; conventional n- or p-type dopant carrier concentrations are altered if these oxygen donors are present. Neutron transmutation doping (NTD) has been used to introduce a uniform concentration of 31P in Si. However, oxygen donors can also be formed in NTD Cz Si during the process of annealing to remove NTD radiation damage. In the present experiments, the carrier concentration of Cz and NTD Cz Si samples was determined as a function of the initial dopant, oxygen, and 31P concentration before and after isothermal or isochronal annealing. It is shown that low temperature (350–500°C) heat treatment can introduce a significant oxygen donor concentration in Cz Si and in NTD Cz Si that contains radiation-induced lattice defects. Intermediate temperature (550–750°C) heat treatment, which is intended to remove oxygen donors or lattice defects, can introduce other oxygen donors; annealing above 750°C is required to remove any of these oxygen donors. Extended (20 h) high-temperature (1000–1200°C) annealing can remove oxygen donors and lattice defects, but a significant concentration of oxygen donors can still be introduced by subsequent low temperature heat treatment. These results suggest that oxygen-related donor formation in NTD Cz Si at temperature below 750°C may serve to mask any annealing study of lattice defects. It is concluded that annealing for 30 min 750°C is sufficient to remove radiation damage in NTD Cz Si when the separate effects of oxygen donor formation are included.
Impairment of Temperate Bacteriophage Adsorption by Brief Treatment of Escherichia coli with Dilute Solutions of Ethylenediaminetetraacetate

Abstract Protass, Jay J. (National Institute of Arthritis and Metabolic Diseases, Bethesda, Md.), and David Korn. Impairment of temperate bacteriophage adsorption by brief treatment of Escherichia coli with dilute solutions of ethylenediaminetetraacetate. J. Bacteriol. 91:143–147. 1966.—Cells of Escherichia coli K-12 treated for 2 min with 2 × 10−4m ethylenediaminetetraacetate (EDTA) are unable to adsorb the temperate bacteriophages λvir and 434 but show no impairment of their ability to adsorb T-even phages or T5. This finding is consistent with the hypothesis that there are basic structural differences between the cell-wall receptors involved in the adsorption of the temperate and T classes of coliphages.
Hardiness and Spiritual Well-Being Among Social Work Students: Implications for Social Work Education

The challenge today for social work students is how to address the professional and educational demands placed on them as they attend to the development of the whole person. This article reports the findings from a 1994 study of social work students. Data collected from a survey of 105 social work students showed significant relationships among hardiness, spiritual well-being, and self-esteem. Spiritual well-being and hardiness were found to be strong predictors of self-esteem. This article discusses the need to explore the role of spiritual well-being as well as implications for research, practice, and education.
HLA Antibody testing- it’s not a one stop assay

HLA laboratories rely on single antigen (SA) assays to determine unacceptable antigens and perform virtual crossmatches (vXM) that can immunologically guide clinicians in the identification of an appropriate donor. Although solid phase antibody detection assays are sensitive, specific and robust-instances arise when further testing is needed to verify results or resolve inconsistencies between these tests. Patient S.T. is a 50 year old male diagnosed with heart failure. Routine work-up in our laboratory is to evaluate % FlowPRA and compare those results to solid phase assays on a Luminex platform which measures the breadth and strength of antibodies in a patient’s sera. Patient S.T. had two samples tested three months apart with a class I FlowPRA of 58% and 62%, respectively. However, The Luminex SA results consistently demonstrated only 5 class I (all B15) antibodies in the positive MFI range leading to a cPRA of about 15%. Moreover, the internal negative control values were > 2500 MFI leading us to believe that there may be additional specificities masked by the high background. How should we deal with these contradictory test results? Can we rely on a vXM to accept a heart for this patient? To reconcile these seemingly contradictory results and to determine if the antibodies detected by Luminex assays were relevant, surrogate FCXM were performed. Surrogate Donor 1 (B15 positive) was FCXM positive. Surrogate donor 2 (B15 negative) was FCXM negative indicating that non-specific binding/false-positivity due to high background should not affect FCXM interpretation, Importantly, testing using phenotype beads were not affected by high background and further confirmed the presence of B15 antibodies. Due to the presence of HLA antibodies and the high background exhibited by this patient, a prospective FCXM must be performed prior to accepting an organ. In conclusion, this is an example in which different tests provide contradictory (or non-consistent) results - and our approach to resolve these ambiguities to support successful organ transplantation.
Integrating the Science and Art of Using Food as Medicine

The domestication of agriculture approximately 10,000 years ago led to profound environmental changes that have influenced our diet and lifestyle. This has resulted in a global pandemic of nutrition- and lifestyle-related chronic degenerative diseases arising from a mismatch between our ancient genetic makeup and current lifestyle patterns. While conventional medicine tries to address chronic disease by symptom management, newer paradigms, such as integrative and functional medicine, attempt to identify the root cause of chronic diseases. Disease is described as a complex phenomenon comprised of core clinical imbalances in various organ systems and physiological processes resulting from the interplay of environmental inputs such as diet and lifestyle. Nutrition, as determined by dietary patterns consisting of foods with bioactive compounds, is critically involved in the creation and mitigation of disease primarily by disrupting or restoring balance or homeostasis in cellular mechanisms and products. Food serves as an information molecule, directly or indirectly influencing gene expression. Individual genetic predispositions in turn dictate unique dietary needs and requirements. Normalizing multiple biological systems requires a multipronged approach that includes a gradual transition to an unprocessed whole foods diet, knowing and learning about food sources, removing or controlling food allergens, reducing the environmental toxic burden, and following a holistic lifestyle intervention strategy that combines diet, exercise, stress management, and spirituality.
The morphology of the gluteus maximus during human evolution: Prerequisite or consequence of the upright bipedal posture?

The human gluteus maximus differs from that of the other hominoids because of its size and bony attachments. These differences raise questions concerning their sequence of appearance in human evolution. Given that humans practice a unique locomotor style, one wonders if the human gluteus maximus morphology is a prerequisite or a consequence of upright bipedal locomotion. This question is addressed using a computer model that evaluates muscle leverage in a variety of locomotor postures. In this model, the human-like, or ape-like, muscular pattern is imposed upon a representative hindlimb of each of the five extant hominoids. Shapes of the skeletal elements (i.e. ilium and ischium lengths) are adjusted in the computer to simulate an evolutionary progression from an ape to a human skeletal morphology. Changes in the leverage of different parts of the gluteus maximus (measured as moment arms) are monitored during this transition. The results show how the mechanical leverages of the gluteus maximus would have changed in a variety of hypothetical evolutionary sequences that describe an ape to human transition.
Development of Integrated Management Information System for Dairy Producers

Abstract This paper considers the extent to which concepts of an integrated management information system have been or might be developed for application in dairy production. Major features of such a system are described as capabilities to process records for evaluating current and historical states of the business, to project anticipated events and performance in the immediate future as a means of monitoring and controlling current activities, and to provide both long- and short-run projections of physical and financial performance as an aid to planning and decision making. These concepts are discussed in relation to types of decision aids and systems analyses that have been developed for and of dairy production. Two issues in particular are highlighted. The first concerns integration of predictive models with record processing capabilities so that projections for both planning and control are based on the most up-to-date description of the structure, capacity, operating constraints, and policies of the individual business. The second concerns definition of predictive models with respect to simplicity versus accuracy in representation of the complexity and dynamic, holistic properties of biological production systems. Alternative approaches to these problems are discussed. While many components of an effective management information system have been developed, their combination into a single integrated system has not occurred. The structure and anticipated operation of a proposed dairy information system are outlined.
Influence of Localized Muscle Fatigue of the Knee Joint on Gait Parameters Related to Slip Propensity

Existing epidemiological evidence suggests that localized muscle fatigue might be considered as an intrinsic risk factor that causes lack of balance control leading to falls. The goal of the study was to examine how localized muscle fatigue of the knee joint (quadriceps) alters gait parameters that are related to slip propensity. Sixteen healthy young participants were recruited to walk across a vinyl floor surface in two different sessions (Fatigue and No fatigue). Kinematic and kinetic data were collected using a three-dimensional video analysis system and force plates during both sessions. The fatigue session results indicated a substantial increase in heel contact velocity (HCV) and required coefficient of friction (RCOF), as well as a decrease in the transitional acceleration of the whole body COM (TA), walking velocity (WV), and step length (SL). In addition, a positive correlation was observed between RCOF and HCV. These findings provide new insights into the biomechanical relationship between loca...
A 42-Kilodalton Annexin-Like Protein Is Associated with Plant Vacuoles

A 42-kD, calcium-dependent, membrane-binding protein (VCaB42) was associated with partially purified vacuole membranes. Membrane-dissociation assays indicated that VCaB42 binding to vacuole membranes was selective for calcium over other cations and that 50% of VCaB42 remained membrane bound at 61 [plus or minus] 11 nM free calcium. A 13-amino acid sequence obtained from VCaB42 showed 85% similarity with the endonexin fold, a sequence found in the annexin family of proteins that is thought to be essential for calcium and lipid binding. The greatest similarity in amino acid sequence was observed with annexin VIII (VAC-[beta]). The calcium-binding properties and sequence similarities suggest that VCaB42 is a member of the annexin family of calcium-dependent, membrane-binding proteins. Functional assays for VCaB42 on vacuole membrane transport processes indicated that it did not significantly affect the initial rate of calcium uptake into vacuole membrane vesicles. Because VCaB42 is vacuole localized (likely on the cytosolic surface of the vacuole) and is 50% dissociated within the physiological range of cytosolic free calcium, we hypothesize that this protein is a sensor that monitors cytosolic calcium levels and transmits that information to the vacuole.
Bremsstrahlung imaging after 32P treatment for residual suprasellar cyst

A patient with residual suprasellar cystic neoplasm was treated by direct instillation of the 32P colloid. The incidental bremsstrahlung images on a conventional gamma camera helped to localize the pharmaceutical within and outside of the lesion. Advantages of bremsstrahlung imaging and the dosimetry results of phantom studies carried out are described.
When is water not water? Exploring water confined in large reverse micelles using a highly charged inorganic molecular probe.

The interior water pool of aerosol OT (AOT) reverse micelles tends toward bulk water properties as the micelle size increases. Thus, deviations from bulk water behavior in large reverse micelles are less expected than in small reverse micelles. Probing the interior water pool of AOT reverse micelles with a highly charged decavanadate (V10) oligomer using 51V NMR spectroscopy shows distinct changes in solute environment. For example, when an acidic stock solution of protonated V10 is placed in a reverse micelle, the 51V chemical shifts show that the V10 is deprotonated consistent with a decreased proton concentration in the intramicellar water pool. Results indicate that a proton gradient exists inside the reverse micelles, leaving the interior neutral while the interfacial region is acidic.
Ceramide-enriched microdomains in planar membranes

Ceramide has a large effect on the properties of biological membranes, increasing lipid order and promoting lateral phase separation, and plays an important role in cell signaling. This review provides an overview of recent studies of the effects of direct ceramide incorporation and enzymatic ceramide generation on planar supported membranes, including lipid monolayers and supported lipid bilayers. Recent studies have focused on understanding the nucleation, growth and morphology of ceramide gel domains, characterizing the properties of ceramide-rich membrane phases and investigating the effects of ceramide on phase-separated membranes with co-existing liquid-ordered and fluid phases, as models for cellular membranes.
Nautilus—a poor model for the function and behavior of ammonoids?

Inferences drawn from the biology, function, and behavior of closely related living forms facilitate interpretation of the mode of life of groups known only from the fossil record. The choice of phylogenetically relevant modern ‘model organisms’ can have critical bearing on the resulting interpretations. The biology and behavior of fossil ammonoids are often interpreted in the light of evidence derived from the study of modern Nautilus. However, examination of the fossil record and cladistic analyses both indicate that coleoids are much more closely related to ammonoids than is Nautilus. Coleoid biology and behavior differ dramatically from the biology and behavior of Nautilus. Thus, the inclusion of coleoids as examples, rather than reliance on Nautilus alone, produces a strikingly different vision of ammonoid biology and suggests that inferences of ammonoid biology and behavior that rely exclusively on Nautilus should be reviewed. Two features related to swimming ability in Nautilus, static stability and large retractor muscles, are much reduced in many ammonoids, leading to the interpretation that ammonoids were poorer swimmers than Nautilus. However, reexamination of the evidence indicates that static stability should not play a role in the swimming of ammonoids with long body chambers. In addition, functional arguments suggest that a coleoid-like swimming mechanism should have evolved prior to the loss of the body chamber in coleoids. Thus, a coleoid-like swimming mechanism is likely to have evolved prior to the separation of ammonoid and coleoid lineages. A mechanism is proposed by which a coleoid swimming mechanism, independent of retractor muscle size, could function in ammonoids with long body chambers.□Ammonoids, ammonites, evolution, functional morphology, Nautilus, phylogeny.
Self-Report Measures of Psychopathy: What is their Role in Forensic Assessments?

Psychopaths have long been characterized as having a remarkable disregard for the truth, to the extent that deceit is often regarded as a defining characteristic of the syndrome (Porter and Woodworth 2006). Although the PCL-R is considered the general standard for evaluating psychopathy, self-report measures have become more widely available and researched. The current study evaluated the ability of jail detainees with moderate and high levels of psychopathy to successfully engage in Positive Impression Management (PIM) on three self-report measures (i.e., SRP-4, LSRP, and PPI–R). Overall, detainees were successfully able to mask their psychopathy, achieving average scores that are even lower than college and community samples. Predictably, detainees with higher levels of psychopathy were generally able to achieve larger decreases than others on psychopathy measures. To identify PIM, we investigated the PPI-R Virtuous Responding (VR) Scale and a modified Social Desirability–Psychopathy (SDP) index for the SRP-4. Overall, self-report measures of psychopathy evidence only modest convergence with the PCL-R and have proven to be highly susceptible to PIM.
EXTRACTABLE PROTEIN AS A MEASURE OF POSTMORTEM AGE OF REFRIGERATED HADDOCK1

A method has been developed for assessing the post-mortem age of refrigerated haddock based on the extraction and thermal precipitation of protein from tissue in distilled water. As the postmortem age increases beyond 7 days, extractable protein decreases. The method was found to be relatively unaffected by the developing bacterial population and to be highly reproducible. The procedure is particularly useful with haddock having a postmortem age of 9 days or more.
The use of lead isotopic abundances in trace uranium samples for nuclear forensics analysis

Secondary ion mass spectrometry (SIMS), secondary electron microscopy (SEM) and X-ray analysis have been applied to the measurement of U-bearing particles with the intent of gleaning information concerning their history and/or origin. The lead isotopic abundances are definitive indicators that U-bearing particles have come from an ore-body, even if they have undergone chemical processing. SEM images and X-ray analysis can add further information to the study that may allude to the extent of chemical processing. The presence of “common” lead that does not exhibit a radiogenic signature is clear evidence of anthropogenic origin.
A review of Reynolds number studies conducted in the Langley 0.3-m Transonic Cryogenic Tunnel

Initial proof-of-concept results obtained in a pilot transonic tunnel, led to a U.S. decision to apply the cryogenic tunnel concept to the National Transonic Facility (NTF). The pilot tunnel was reclassified as a 'permanent' facility and renamed the 0.3-m Transonic Cryogenic Tunnel (TCT). The 0.3-m TCT, with its ability to operate at temperatures ranging from about 78 K to 340 K, combined with a 6 atmospheres pressure capability, provides extremely high test Reynolds numbers at relatively low model loading. In addition, the ability to vary pressure and temperature independently of Mach number provides a unique capability to conduct studies at a constant dynamic pressure or at a constant Reynolds number with just one model. Attention is given to the simulation of flight conditions, the cryogenic-pressure tunnel concept, the characteristics of the 0.3-m TCT, Reynolds number studies in the three-dimensional test section including a Space Shuttle study, and Reynolds number studies in the two-dimensional test section.
Some simple guidelines to the interpretation of the magnetic signatures seen at the Galilean moons

Abstract Io, Europa, Ganymede and Callisto all interact with a flowing magnetized plasma, that of the nearly corotating jovian magnetosphere. The plasma conditions at each differ as there is a strong variation in the properties of the magnetosphere with radial distance. The properties of the moons vary as well. Thus each of the moons has a unique interaction. In order to understand how to interpret these signatures we examine first the limiting field induced in a permeable moon to determine what size fields demand intrinsic sources. We also examine the implications for remanent field sources imposed by the Runcorn theorem. Electrical conductivity in the ionosphere and interior to the moons can exclude the time varying portion of the external magnetic field. This exclusion can be used to probe for subsurface oceans beneath the crust. In addition to these effects, Europa and Io have sufficient atmospheres that they add mass to the incoming flow. The evidence for this mass loading and its effects on the jovian magnetosphere are reviewed as are its effects on the more classic signatures described above. When all these effects are considered we conclude that Io may have an intrinsic field with a moment as large as 10 13 Tm 3 although it is possible that this signature results from permeable material within Io. Europa has a conducting interior, most probably due to a saltwater ocean near its surface. Ganymede has an intrinsic field that is dynamo driven and Callisto has a conducting layer like that of Europe. Earlier observations by Voyager can readily be interpreted in terms of this mass loading scenario. The slowed cold flow behind Io provides a suitable source via the interchange instability for the cold torus well inside the orbit of Io.
Kinetics of crystal growth of nanogoethite in aqueous solutions containing nitrate and sulfate anions

Iron oxyhydroxide nanoparticles, relatively abundant and highly reactive components of most natural ecosystems, are known to grow via the oriented attachment (OA)-based crystal growth pathway. Here, we conducted experiments in highly alkaline solutions containing sulfate and nitrate anions to test the differential impact of these anions on the various steps in this growth pathway. Nanogoethite (α-FeOOH) was prepared by reacting ferric sulfate or ferric nitrate with potassium hydroxide, and aging at room temperature, 50, 60 and 70 °C. X-ray diffraction (XRD) was used to confirm the synthesis of goethite and Rietveld analyses were used to determine the particle sizes in samples with different aging times. Particle morphology and microstructure of some samples were investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM images confirmed growth of goethite nanorods via OA. OA growth kinetics were modeled using a previously reported kinetic equation. An Arrhenius plot indicated the activation energy for OA-based crystal growth in the sulfate system was 45.2 kJ mol−1, higher than in the nitrate system (23.1 kJ mol−1). The magnitude of the activation energy suggests that the rate-limiting step for OA growth is diffusion of nanoparticles in solution, a first step necessary for particle–particle attachment. We attribute the larger effect of sulfate compared to nitrate on the activation energy to greater structuring of water by sulfate. The kinetic pre-exponential factor for the sulfate system is much higher than that for the nitrate system, and results in faster growth kinetics at high temperature. Sulfate may accelerate the dehydration of the interface, a subsequent step required for OA-based growth, possibly through increasing the rate of water exchange at the nanoparticle surfaces. These findings motivate conduction of new experiments to further probe the kinetics of individual steps in OA-based crystal growth, suggest routes to inhibit or promote OA relative to atom-by-atom growth pathways, and provide clues to how variation in solution chemistry could impact mineral growth in natural systems.
Active and passive noise control using electroactive polymer actuators (EAPAs)

Electro-active polymer actuators (EAPA) have been a topic of research interest in the recent decades due to their ability to produce large strains under the influence of relatively low electric fields as compared to commercially available actuators. This paper investigates the feasibility of EAPA for active and passive cabin noise control. The passive damping characteristics of EAPA were determined, by measuring the transmission loss of four samples of various thickness and composition in an anechoic chamber in the 200 - 2000 Hz frequency range. This was then compared to that of Plexiglas and silicone rubber sheets of comparable thickness. The transmission loss of EAPA and Plexiglas were observed to be about the same. The transmission loss of EAPA was greater than that of silicone rubber, of the same thickness. The experimental and theoretical results computed using the mass law agree well. EAPA produces a strain of 0.006 for an applied field of 1 V/m. The ability of EAPA to potentially provide active as well as passive damping in the low to intermediate frequency range, along with being light- weight, pliable and transparent, makes it attractive for noise control applications as active/passive windows or wall papers.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Direct-drive–ignition designs with mid-Z ablators

Achieving thermonuclear ignition using direct laser illumination relies on the capability to accelerate spherical shells to high implosion velocities while maintaining shell integrity. Ablator materials of moderate atomic number Z reduce the detrimental effects of laser–plasma instabilities in direct-drive implosions. To validate the physics of moderate-Z ablator materials for ignition target designs on the National Ignition Facility (NIF), hydro-equivalent targets are designed using pure plastic (CH), high-density carbon, and glass (SiO2) ablators. The hydrodynamic stability of these targets is investigated through two-dimensional (2D) single-mode and multimode simulations. The overall stability of these targets to laser-imprint perturbations and low-mode asymmetries makes it possible to design high-gain targets. Designs using polar-drive illumination are developed within the NIF laser system specifications. Mid-Z ablator targets are an attractive candidate for direct-drive ignition since they present better overall performance than plastic ablator targets through reduced laser–plasma instabilities and a similar hydrodynamic stability.
Chloroperoxidase-catalyzed chlorination of didechloroaglucovancomycin and vancomycin

The chloroperoxidase (CPO) from Caldariomyces fumago catalyzed the chlorination of didechloroaglucovancomycin and vancomycin in the presence of hydrogen peroxide and chloride ion. Chlorination of didechloroaglucovancomycin has afforded new derivatives, with one and two chlorine atoms attached onto the aromatic ring of residue 7 of didechloroaglucovancomycin. Vancomycin was similarly chlorinated under the same conditions to furnish a new dichloro derivative.
PAF priming of human PMNs activates a preassembled P38 MAPK module involving RAC

Abstract Mitogen activated protein kinase (MAPK) signaling constructs are three-tiered kinase modules. The initial kinase, an MKKK, may be activated by interaction with a small GTPase (i.e., RAC). P21-activated kinase (PAK) is an MKKK activated by RAC. Recent evidence suggests that platelet activating factor (PAF) priming of PMNs for superoxide production involves rapid RAC/P38 MAPK activation. Recognizing the rapid priming by PAF, we hypothesize that a preassembled P38 MAPK module involving RAC is activated by PAF stimulation of human PMNs. Methods: Human PMNs were obtained and stimulated with 2 μM PAF. PAK pull downs were performed on PMN lysates (1.25 × 107 cells) whereby; cellular PAK and its adherent proteins were collected. Proteins were separated and immunoblotted for RAC, total P38 and activated (phosphorylated) P38. Results: In resting PMNs there was very little activated RAC, as determined by its binding to PAK. PAF stimulation increased the amount of activated RAC bound to and precipitated with PAK. P38 precipitated with PAK in resting and PAF stimulated PMNs. The quantity of total P38 bound to PAK did not change following PAF stimulation. In resting PMNs, very little PAK bound P38 was active. PAF stimulation increased the amount of active P38 bound to and precipitated with PAK. See figure.Conclusions: PAK, an MKKK, is bound to P38 MAPK in human PMNs at rest and following PAF stimulation. RAC activation occurs rapidly following stimulation. Activated RAC binds to, and activates PAK. RAC/PAK activation corresponds to the activation of the PAK bound P38 MAPK. These results indicate the existence of a preformed PAK-MKK- P38 MAPK complex in human PMNs, involving RAC. These findings represent new insights into MAPK module signaling in human PMNs during PAF priming. Download : Download high-res image (35KB) Download : Download full-size image
Development of Steinernema feltiae (Rhabditida: Steinernematidae) in diseased insect hosts

Abstract The interaction between the entomopathogenic nematode, Steinernema feltiae , and a nuclear polyhedrosis virus (NPV) or Bacillus thuringiensis var. kurstaki in a common host was investigated. S. feltiae reproduced successfully in 68.3% of moribund hosts infected with NPV. S. feltiae infectives retained sufficient NPV to infect neonate larvae of Spodoptera exigua . Nematodes from NPV-infected hosts when fed whole or macerated to neonate S. exigua larvae caused 44 and 58% NPV infections, respectively. On the other hand, S. feltiae did not produce progeny in B. thuringiensis -infected hosts, except in a few cases. Those hosts which had a dual infection had B. thuringiensis infection in the anterior part and S. feltiae infection in the posterior part of the body. In general, B. thuringiensis -killed insects were not satisfactory hosts for S. feltiae .
Heat-Pulse Propagation in p-Type Si and Ge under Uniaxial Stress

Heat-pulse propagation has been studied in $p$-type silicon and $p$-type germanium as a function of uniaxial stress (up to ${10}^{9}$ dyn ${\mathrm{cm}}^{\ensuremath{-}2}$) and of pulse temperature. The coupling between thermal phonons and the stress-split ground state of acceptors has been calculated using the effective-mass approximation for the relevant acceptor-hole wave functions. In addition to the $s$-like parts of the expansion for the envelopes usually considered, $d$-like parts of the expansion have been included here. The important phonon scattering rates due to stress-split acceptor states were derived. The rates were obtained for resonance absorption (for phonons with energies close to the splitting energy), and for several second-order processes. In addition, Rayleigh scattering of phonons by isotopic impurities has been evaluated. A black-body model for phonon emission from the heat-pulse generator was assumed. The total calculated scattering rate agrees with the observed stress dependence of the heat-pulse amplitudes when the effects of internal strains, and, in the case of high acceptor contents, of phonon multiple scattering are taken into account. A fit of the experimental results to the calculated results yields two distinct sets of values for the "static" (${a}^{*}q\ensuremath{\ll}1$) and "dynamic" (${a}^{*}q\ensuremath{\gtrsim}1$) deformation-potential constants (${a}^{*}$ is the effective Bohr radius of the impurity and $q$ is the wave number of the relevant wave component). This observation resolves the apparent conflict in previously reported values of these constants, obtained from separate studies in the static (e.g., piezoreflectance) and dynamic (thermal-conductivity) regimes. The present theory does not yield such distinctions for the two regimes. It is concluded, therefore, that the effective-mass approximation is not adequate for describing the full range of frequency-dependent stress effects. It should be emphasized that the heat-pulse study is particularly well suited for investigating these differences because the constants for the two regimes are derived within the framework of the same experiment.
Effect of Electromagnetic Field on the As-Cast Structure of HMn084 Brass

The effect of electromagnetic field on the solidification structure of HMn084 brass (Cu-20%Zn-7.5%Mn-5.5%Al-1.5%Si-1%Fe-0.5%Pb in mass%) had been investigated in this paper. The results show that the as-cast structure of HMn084 brass is composed of matrix β-phase, small amount of α-phase and silicide (Mn, Fe)5Si3. Applying electromagnetic field during the solidification of HMn084 brass can refine grain and silicide phase, promote the uniform distribution of silicide phase. The morphology of silicide phase changes from coarse acicular and massive shape to fine acicular and massive shape. The above-mentioned effects become more obvious with the increasing in current intensity.
Size-Distance Perception in Preschool Children.

Abstract Children between three and six years of age matched the “apparent” and “real” size of familiar and unfamiliar objects 3, 6, or 9 feet away. Prior to the experimental sessions, the children were divided into two groups: (a) those who could distinguish the phenomenal from the real sizes of the arcs in the Jastrow illusion (the “Realists”) and (b) those who could not (the “Phenomenalists”). The results suggest that all children perceived size constancy up to distances of 9 feet solely on the basis of visual information.
Comparison of the antinociceptive and antispastic action of (−)-baclofen after systemic and intrathecal administration in intact, acute and chronic spinal rats

Abstract Baclofen is particularly effective in treating spasticity of spinal origin in humans. However, most investigations of this drug in animals have only assessed its antinociceptive effect, presumably because of the difficulty in developing animal models of spasticity. This study attempted to evaluate both, the antinociceptive and antispastic action of (−)-baclofen (the more active enantiomer) by incorporating the chronic spinal preparation, in which spasticity gradually develops following spinal transection. Separate groups of intact, acute (1 day) or chronic (20–25 days) spinal rats were pretested on the nociceptive tail-flick (TF) assay prior to either subcutaneous (SC; 1–30 mg/kg) or intrathecal (IT; 0.1–12 μg) injection of (−)-baclofen and retested at specific post-injection intervals. Hindlimb spasticity was elicited in chronic spinal rats by mechanical stimulation to the abdomen. Because the clinical use of baclofen generally involves chronic administration, both responses were tested for 3 successive days to assess tolerance. Results confirmed the analgesic effect of SC and IT (−)-baclofen in intact rats. As previously reported, the antinociceptive effect of IT (−)-baclofen was increased in acute spinal rats. However, three weeks after spinalization there was a profound decrease in this response. In contrast, antinociception produced by SC (−)-baclofen was reduced in acute and chronic spinal rats compared to intact animals; but there was no difference between the acute and chronic conditions. In spite of this differential decrease in antinociception after IT, relative to SC, administration, both routes of administration produced an antispastic effect in chronic spinal rats. There was no antinociceptive tolerance to SC administration and only minimal tolerance to IT (−)-baclofen (in intact rats); the antispastic effect did not become tolerant. A peripheral action might explain the dichotomy between SC and IT (−)-baclofen in regard to antinociception. However, further research is needed to determine why both routes of administration were effective against spasticity while only SC (−)-baclofen retained an antinociceptive action in chronic spinal rats.
A 30-kDa alternative translation product of the CCAAT/enhancer binding protein alpha message: transcriptional activator lacking antimitotic activity.

Abstract Full-length (42 kDa) CCAAT/enhancer binding protein alpha (C/EBP alpha) (p42) has been implicated in the transcriptional activation of adipocyte genes including the 422(aP2) and C/EBP alpha genes during differentiation of 3T3-L1 preadipocytes. We have identified a 30-kDa isoform (p30) of C/EBP alpha that is expressed by 3T3-L1 adipocytes, mouse adipose tissue, and rat liver. In vitro translation of wild-type C/EBP alpha mRNA or transient transfection with a wild-type C/EBP alpha vector gave rise to similar levels of p42 and p30. Mutational analysis revealed that p30 is an alternative translation product initiated at the third in-frame methionine codon of the C/EBP alpha message. p30C/EBP alpha binds to the C/EBP sites within and activates reporter gene expression driven by the 422(aP2) and C/EBP alpha gene promoters. Although transfection of 3T3-L1 preadipocytes with a strong p30C/EBP alpha expression vector is insufficient to induce differentiation, this vector advances the differentiation program. Unlike p42C/EBP alpha, which inhibits cell proliferation, p30C/EBP alpha is not antimitotic. Thus, the N-terminal 12-kDa segment of full-length C/EBP alpha contains an amino acid sequence necessary for antimitotic activity. During differentiation of 3T3-L1 preadipocytes and during hepatocyte development, the cellular p42C/EBP alpha/p30C/EBP alpha ratio changes, raising the possibility of a regulatory role.
Applications of some formulas for finite Markov chains

Abstract We present some explicit matrix formulas for a finite state Markov chain. The first gives sums of probabilities along some general subsets of paths. Another formula yields the probability mass function (pmf) of the random variable which adds costs along subsets of paths. We then discuss how these formulas can be used to efficiently compute expected values of a function of the sum of costs along paths, as well as related applications. We conclude by describing a procedure allowing us to avoid using Monte Carlo simulation in stochastic approaches to solving some general boundary value problems. Instead, we show how to evaluate the relevant expected values exactly for discretizations of the original continuous problem.