cssi/SciSciGPT-SciSciNet huggingface dataset:
Differences in the Nature of the Phosphoryl Transfer Transition State in Protein Phosphatase 1 and Alkaline Phosphatase: Insights from QM Cluster Models.

Quantum mechanical (QM) cluster models are used to probe effects on the catalytic properties of protein phosphatase 1 (PP1) and alkaline phosphatase (AP) due to metal ions and active site residues. The calculations suggest that the phosphoryl transfer transition states in PP1 are synchronous in nature with a significant degree of P-Olg cleavage, while those in AP are tighter with a modest degree of P-Olg cleavage and a range of P-Onuc formation. Similar to observations made in our recent work, a significant degree of cross talk between the forming and breaking P-O bonds complicates the interpretation of the Bronsted relation, especially in regard to AP for which the computed βlg/βEQ,lg value does not correlate with the degree of P-Olg cleavage regardless of the metal ions in the active site. By comparison, the correlation between βlg/βEQ,lg and the P-Olg bond order is more applicable to PP1, which generally exhibits less variation in the transition state than AP. Results for computational models with swapped metal ions between PP1 and AP suggest that the metal ions modulate both the nature of the transition state and the degrees of sensitivity of the transition state to the leaving group. In the reactant state, the degree of the scissile bond polarization is also different in the two enzymes, although this difference appears to be largely determined by the active site residues rather than the metal ions. Therefore, both the identity of the metal ion and the positioning of polar or charged residues in the active site contribute to the distinct catalytic characteristics of these enzymes. Several discrepancies observed between the QM cluster results and the available experimental data highlight the need for further QM/MM method developments for the quantitative analysis of metalloenzymes that contain open-shell transition metal ions.
Wind farm active and reactive power management

One of the most critical aspects in the wind farm sector is a power management throughout different wind generators. This paper proposes an improvement power management strategy based on the hybrid...
Advancing Gender Equity and Sense of Belonging in Computing: Are Documented Best Practices Representative of Upward Transfer Students?

Supporting upward transfer students is critical to diversifying STEM. This study provides insight into how we can best support upward transfer students in computing, one of the least diverse STEM d...
High hydrostatic pressure and the dissection of fertilization responses: I. The relationship between cortical granule exocytosis and proton efflux during fertilization of the sea urchin egg

High hydrostatic pressure applied between sperm attachment and the onset of cortical granule exocytosis will inhibit this exocytotic event in sea urchin eggs. Such pressure-treated zygotes, nevertheless, are activated and capable of development. Thus, this technique can be used as a tool to study the relationship between cortical granule breakdown and other fertilization-related responses. We have studied whether the exocytosis of cortical granules is necessary for proton efflux (acid release) to occur. Our results indicate that although Ca2+ is released while the eggs are under pressure (a prerequisite for the following events to take place), cortical granule exocytosis and acid release are pressure-sensitive and completely inhibited at pressures above 400 atm (6000 psi) and 275 atm (4000 psi), respectively. However, upon decompression, acid release is initiated which amounts to 65-70% of that seen in the unpressurized controls, suggesting that the efflux mechanism does not require cortical granule exocytosis and must result from some modification of the original plasma membrane of the egg. The remaining 30-35% of the acid release is related to cortical granule exocytosis, since it can be obtained upon induction of the cortical granule fusion 30 min later under atmospheric pressure. The initiation of acid release after decompression indicates that the efflux mechanism is not transiently turned on at fertilization, but undergoing long-term modification; the recovery of the ability to induce cortical granule fusion after fertilization under pressure suggests a refilling of cytoplasmic Ca2+ stores within this time course.
AET-treated platelets: their usefulness for platelet antibody detection and an examination of their altered sensitivity to immune lysis

2-Aminoethylisothiouronium bromide (AET) increases the sensitivity of blood cells to complement-mediated immune lysis. We compared the sensitivities of untreated or AET-treated platelets to immune lysis induced by different types of platelet antibody in the 51Cr platelet lysis test. AET platelets were 8–16 times more sensitive to autoantibody and alloantibody, but 8–16 times less sensitive to drug- dependent antibody. AET-platelets bound similar amounts of alloantibody but less drug-dependent antibody, and they lysed at higher complement dilutions than did untreated platelets. AET-platelets detected 10 of 25 autoantibodies, 9 of 9 alloantibodies, and 5 of 8 drug-dependent antibodies. Untreated platelets detected 1 of 25, 6 of 9, and 7 of 8 of these respective platelet antibodies. The use of AET-platelets in the 51Cr platelet lysis test increases its sensitivity for detecting non- drug-dependent platelet antibodies. AET-platelets resemble paroxysmal nocturnal hemoglobinuria (PNH) platelets in their enhanced sensitivity to complement-mediated lysis. They differ from PNH platelets in their insensitivity to immune lysis induced by drug-dependent antibodies and, in this respect, are similar to Bernard-Soulier syndrome platelets.
Combined optical modulation formats and their applications

The realization of high-speed optical networks hinges on the efficient use of network resources. To optimize the utilization of the limited network resources, we have developed novel combined optical modulation formats. Combined optical modulation allows the transmission of two independent data streams simultaneously on the same optical carrier using a separate modulation format for each stream. Each individual data stream is then received separately with a separate optical receiver. The use of combined optical modulation optimizes the utilization of network resources by allowing the transmission of two separate data streams with a single transmitter laser.
Topography of prostaglandin H synthase. Antiinflammatory agents and the protease-sensitive arginine 253 region.

Abstract Prostaglandin H synthase catalyzes two reactions: the bis-dioxygenation of arachidonic acid to form prostaglandin G2 (cyclooxygenase activity), and the reduction of hydroperoxides to the corresponding alcohols (peroxidase activity). The cyclooxygenase activity can be selectively inhibited by many nonsteroidal antiinflammatory agents including indomethacin. In the native synthase, there is a single prominent protease-sensitive region, located near Arg253; binding of the heme prosthetic group makes the synthase resistant to proteases. To investigate the spatial relationship between the area of the synthase which interacts with indomethacin and the protease-sensitive region, the effects of indomethacin and similar agents on the protease sensitivity of the two enzymatic activities and of the synthase polypeptide were examined. Incubation of the synthase apoenzyme with trypsin (3.6% w/w) resulted in the time-dependent coordinate loss (75% at 1 h) of both enzymatic activities and the cleavage (85% at 1 h) of the 70-kDa subunit into 38- and 33-kDa fragments, indicating that proteolytic cleavage of the polypeptide at Arg253, destroyed both activities of the synthase simultaneously. Indomethacin, (S)-flurbiprofen, or meclofenamate (each at 20 microM) rendered both activities and the synthase polypeptide (at 5 microM subunit) resistant to attack by trypsin or proteinase K; these agents also inhibited the cyclooxygenase activity of the intact synthase. Two reversible cyclooxygenase inhibitors, ibuprofen and flufenamate, also made both of the activities and the synthase polypeptide more resistant to trypsin. Titration of the apoenzyme with indomethacin (0-3 mol/mol of synthase dimer) resulted in proportional increases in the inhibition of the cyclooxygenase and in the resistance to attack by trypsin. (R)-Flurbiprofen did not increase the resistance to protease or appreciably inhibit the cyclooxygenase. These results suggest that the same stereospecific interaction of these agents with the synthase that produced inhibition of the cyclooxygenase led to a decreased accessibility of the Arg253 region to proteases. Aspirin treatment made the synthase less resistant to trypsin; aspirin-treated synthase became more resistant to trypsin when it was incubated with indomethacin before addition of the protease. The presence of 50 microM arachidonate during digestion of apoenzyme or aspirin-treated apoenzyme with trypsin did not decrease the cleavage of the synthase subunit.(ABSTRACT TRUNCATED AT 400 WORDS)
Results on the optimal (free-order) H/sub 2//l/sub 1/ solution

This paper summarizes an analytical approach to the solution of the H/sub 2//l/sub 1/ optimization problem. It is shown that the case where T/sub zw//spl ne/T/sub mr/ does not necessarily result in finite impulse response (FIR) solutions for both T/sub zw/ and T/sub mr/. It is conjectured that the solution to the general SISO (or MIMO one block) H/sub 2//l/sub 1/ problem will result in an FIR sequence for T/sub mr/, but not necessarily for T/sub zw/. Based on this conjecture, a numerical approach to the solution is developed which is capable of solving (exactly) for the optimal H/sub 2//l/sub 1/ compensator using a finite truncation level. The numerical method is demonstrated with a SISO F-16 aircraft example.
A Tribute to the Honorable Phyllis A. Kravitch

This is a tribute to Judge Phyllis A. Kravitch, who honorably served two decades on the bench during a period of great transition in the South.
Crystalline L-Ribulose 5-Phosphate 4-Epimerase from Escherichia coli

Abstract l-Ribulose 5-phosphate 4-epimerase has been crystallized from l-arabinose-induced cells of Escherichia coli B/r strain F' araB-24/araB-24 after a 40-fold purification. The enzyme is homogeneous in the ultracentrifuge and 98% pure by acrylamide gel disc electrophoresis. The molecular weight determined by sedimentation equilibrium is 1.03 ± 0.01 x 105. The enzyme is free of d-ribulose 5-phosphate 3-epimerase activity, does not exhibit any cofactor requirement, and shows maximal activity from pH 7 to 10. An amino acid analysis is presented.
Relationship of the hexose monophosphate shunt to the endogenous metabolism of cell-free extracts of Mycobacterium phlei.

Abstract Sutton, W. B. (The Lilly Research Laboratories, Indianapolis, Ind.). Relationship of the hexose monophosphate shunt to the endogenous metabolism of cell-free extracts of Mycobacterium phlei. J. Bacteriol. 85:476–484. 1963.—The endogenous reduction of 2,6-dichlorophenol-indophenol (DPIP) by cell-free extracts of Mycobacterium phlei has been linked to the presence of glucose-6-phosphate (G-6-P) dehydrogenase functioning in connection with a reduced triphosphopyridine nucleotide (TPN)-DPIP reductase. The necessary substrate and coenzyme, i.e., G-6-P and TPN, are contained in the cell-free bacterial extract. The only required addition to activate the system is a suitable electron acceptor. The accumulation of G-6-P and the presence of 6-phosphogluconic dehydrogenase in the cell-free extract suggest that the hexose monophosphate shunt mechanism is impaired by sonic treatment of M. phlei.
Impact of Sample Type on Rapid Detection of Influenza Virus A by Cytospin-Enhanced Immunofluorescence and Membrane Enzyme-Linked Immunosorbent Assay

Cytospin-enhanced direct fluorescent-antibody assay (DFA) detected 49 (92.5%) and rapid membrane enzyme-linked immunosorbent assay (ELISA) detected 40 (75.5%) of 53 influenza virus A-positive samples. All 15 positive nasopharyngeal aspirates from children were detected by both tests. In contrast, 34 of 38 (89.5%) positive swabs from adults were detected by DFA, but only 25 (66%) were detected by ELISA.
Immune Responses to HIV in the Female Reproductive Tract, Immunologic Parallels with the Gastrointestinal Tract, and Research Implications

The female reproductive tract is a major site of mucosa-associated lymphoid tissue and susceptibility to HIV infection, yet the tissue site(s) of infection and the impact of HIV infection on this important mucosal tissue remain poorly understood. CD4(+) T cells and other cell types expressing the major coreceptors for HIV, CCR5, and CXCR4 are abundant in both the lower reproductive tract (endocervix and vagina) and the upper tract (endocervix and uterus) and are highly susceptible to infection. Antiviral defenses in the female reproductive tract are mediated by a variety of soluble factors and by mucosal effector cells that differ phenotypically from their counterparts in blood. The immunologic characteristics of the female reproductive tract parallel those of the gut, where major HIV-related immunologic injury occurs. The susceptibility of the female reproductive tract to HIV infection and immunopathogenesis suggests important new avenues for further research.
How social workers help lawyers

James L. Scherrer, M SIV, is a recent graduate of the Jane Addams School of Social Work, University of Illinois at Chicago Circle. Although both lawyers and social workers claim to have a common goal —the welfare of the people they serve —much has been written on the diffi culties and conflicts that character ize the relationship between the two groups.1 Out of the wealth of profes sional material comes one plaintive cry: What can social work offer the legal profession? 2 This question, which neither lawyers nor social workers have been able to answer satisfactorily, forms the basis for this article. To answer it, the author will draw on his experience working with juveniles and their families acquired during his field placement with the Juvenile Law Proj ects, Northwestern University Legal Assistance Clinic.
Parsimonious 3D post‐stack Kirchhoff depth migration

Parsimonious post-stack migration is extended to three dimensions. By tracing single rays back along each incident wave direction (as determined by a local slant stack at the receivers), the ray tracing can be embedded in the migration. This approach significantly reduces the computer time and disk space needed because it is not necessary to build and save image time maps; 3D migration can be performed on a workstation or personal computer rather than using a supercomputer or cluster. The location of a reflector in the output image is defined by tracing a zero-offset ray to the one-way traveltime (the image condition); the orientation of the reflector is defined as a surface perpendicular to the raypath. The migration impulse response operator is confined to the first Fresnel zone around the estimated reflection point, which is much smaller than the large isochronic surface in traditional Kirchhoff depth migration. Additional efficiency is obtained by applying an amplitude threshold to reduce the amount of data to be migrated. Tests on synthetic data show that the proposed implementation of parsimonious 3D post-stack Kirchhoff depth migration is at least two orders of magnitude faster than traditional Kirchhoff migration, at the expense of slightly degraded migration image coherence. The proposed migration is expected to be a useful complement to conventional time migrations for fast initial imaging of subsurface structures and for real-time imaging of near-offset sections during data acquisition for quality control.
Biallelic expression of all four IGF-II promoters and its association with increased methylation of H19 gene in human brain

The human IGF-II gene is maternally imprinted in all tissues except adult liver and the choroid plexus/leptomeninges of the central nervous system where IGF-II is biallelically expressed. In human liver, it has recently been reported that this biallelic expression only involves the promoter P1 while the promoters P2-P4 direct IGF-II transcription monoallelically. To explore whether or not biallelic expression of the IGF-II promoters in human CNS displays the same pattern as in liver, we examined the allelic expression status of the four IGF-II promoters in human brain. We found that all four IGF-II promoters in human fetal and adult brain were expressed from both parental alleles. Furthermore, the levels of methylation of the 3' region of H19 gene in fetal brain were higher than those in other tissues with monoallelic expression of IGF-II. Since similar findings have been reported in Wilms' tumor, these data suggest a similar mechanism may be responsible for loss of imprinting of IGF-II in normal brain and Wilms' tumor.
Embracing Change: Exploring How Creative Professionals Use Interactive Media in Advertising Campaigns

Advertising agencies are incorporating new forms of interactive media into campaigns as media continues to rapidly change. The purpose of this phenomenological qualitative study is to explore how five creative professionals at leading advertising agencies in the Midwest are integrating interactive media into campaigns. Through a series of interviews this project helps solidify what it means to integrate interactive media. The findings illustrate a fundamental shift in an industry that is moving away from “advertising.” An industry built around traditional media now requires creatives to incorporate dynamic, mobile, and social media into the marketing mix. Advertising agencies must engage audiences while embracing change by building interactivity into their “DNA.” Professionals and educators will benefit from these findings that identify traits, skills, and strategies to stay current with a media environment that changes daily.
Evolved Gas Analysis Investigation of the Reaction between Tris(2,4-pentanedionato)aluminum and Water Vapor in Chemical Vapor Deposition Processes To Produce Alumina

Evolved gas analysis−Fourier transform infrared spectroscopy was used to investigate the pyrolysis of tris(2,4-pentanedionato)aluminum on glass surfaces between 500 and 900 K in vacuum and in low-pressure water vapor atmospheres. Pyrolysis of tris(2,4-pentanedionato)aluminum in vacuum produced Al2O3, carbon, water vapor, and several volatile organic products. This pyrolysis is surface enhanced and has an apparent activation energy of ∼100 kJ/mol. Water vapor reacted with the tris(2,4-pentanedionato)aluminum to form 2,4-pentanedione and Al2O3. Largely pure Al2O3 was formed between 600 and 700 K in a water vapor atmosphere. This reaction was first order in the water vapor pressure. The order in tris(2,4-pentanedionato)aluminum was modeled well by the Langmuir adsorption isotherm. The apparent activation energy for the production of 2,4-pentanedione varied with the reaction conditions and had a lower limit of ∼28 kJ/mol when the reaction was run in excess water vapor. Possible reaction sequences are given fo...
Proposals for Improving GPRA Annual Performance Plans

The Government Performance and Results Act process is now well embedded in the departments and agencies, and it is now timely to consider ways to improve the value of agency plans and reports, both to the Congress and to agency managers. This article offers several recommendations about how Annual Performance Plans can be made more valuable.
Providing a Realist Perspective on the eyeGENE Database System

One of the achievements of the eyeGENE Network is a repository of DNA samples of patients with inherited eye diseases and an associated database that tracks key elements of phenotype and genotype information for each patient. Although its database structure serves its direct research needs, eyeGENE has set a goal of enhancing this structure to become increasingly well integrated with medical information standards over time. This goal should be achieved by ensuring semantic interoperability with other information systems but without adopting the incoherencies and inconsistencies found in available biomedical standards. Therefore, eyeGENE’s current pragmatic perspective with focus on data and information, rather than what the information is about, should shift to a realism-based perspective that includes also the portion of reality described, and the competing opinions that clinicians may hold about it. An analysis of eyeGENE’s database structure and user interfaces suggests that such a transition is possible indeed.
Temporal characterization of a picosecond-laser-pumped x-ray laser for applications

Compact soft x-ray laser sources are now used routinely for various applications primarily because of their high repetition rate, high photon fluence and short pulse duration characteristics. For some of these applications, for example interferometry of high density laser-produced plasmas, longer optical drive pulses, 6 - 13 ps (FWHM), have been implemented to maximize the x-ray output and coherence. It is therefore important to know the x-ray laser pulse length, shape and repeatability for these specific experiments as a baseline measurement but also to better understand the temporal behavior as a function of the pumping conditions in general. We report a detailed temporal characterization of the picosecond-driven 14.7 nm Ni-like Pd ion x-ray laser on the Compact Multipulse Terawatt (COMET) laser at LLNL using an ultrafast x-ray streak camera measurement of a horizontal slice of the near-field x-ray laser pattern. This is measured as a function of the chirped pulse amplification pumping laser conditions, including varying the pump pulse from 0.5 - 27 ps (FWHM), varying the plasma column length as well as investigating traveling wave (TW) and non-TW irradiation conditions.
The physics of tablet compression. VII. Determination of energy expenditure in the tablet compression process

Abstract Energy expended in the tablet compression process was calculated by consideration of the magnitude and relation between the several compression variables. In the compression of about 0.4 Gm. of unlubricated sulfathiazole granulation to a maximum force of 1200 Kg, on the lower punch with flat‐faced 3/8‐inch punches, about 8.6 calories were expended. For about the same weight of lubricated granulation the corresponding value was about 2.0 calories. By considering that only energy expended in the process of eliminating void space to form the tablet caused a temperature rise in the tablet, the temperature rise expected in the lubricated or unlubricated tablets mentioned above would be about 5°. When the energies expended in the processes of tablet ejection, overcoming wall friction and removing the upper punch from the die, were summed for a single punch machine making these tablets at the rate of 100 per minute, it was found that 43 kilocalories would be expended in each hour of operation if the tablets were unlubricated. If lubricated granulation were used the value would be 3 kilocalories. The bulk of these expenditures would probably cause heating of the punches and die and if the granulation was either poorly lubricated or unlubricated the heating might be severe.
Determinant-regulated onset of experimental autoimmune encephalomyelitis: distinct epitopes of myelin proteolipid protein mediate either acute or delayed disease in SJL/J mice.

In the present study we address the question of whether distinct self-determinants can target alternative autoimmune disease patterns in experimental autoimmune encephalomyelitis (EAE), an animal model widely used for studying multiple sclerosis. We have found that the clinical course of EAE can be determined by the target peptide selected for induction of disease. In SJL/J mice, actively induced and passively transferred EAE mediated by the immunodominant PLP determinants p139–151 and p178–191 consistently produced a rapid onset of severe clinical signs. In contrast, a delayed onset of both active and passive EAE is associated with the nondominant cryptic PLP determinant p104–117. The delayed disease induced with p 104–117 is not associated with any unusual peptide feature, with bystander immunoregulation, with inept class II MHC binding, or with failure to induce T cell expression of CD44, VLA-4, or IL-2 receptor upon activation. However, delayed disease is associated with innate qualities oftheTcell re...
Do medical school surgical rotations influence subspecialty choice

Abstract Background.A comprehensive exposure to general surgery is essential for medical students pursuing careers in surgery. Occasionally, students applying for surgical residency positions must choose a subspecialty field prior to starting their residency training. Often, this decision is heavily based on their experience on various surgical clerkships. Materials and methods. To determine if surgical clerkships influence subspecialty choice, we surveyed medical students who interviewed for general surgery training over a 2-year period at The Johns Hopkins Hospital. Results. Of 211 surveys sent, 146 were returned (66%). The mean age of the students was 26 ± 0 years with 21% being female. Students anticipating subspecialization in cardiothoracic, plastic, pediatric, and transplant surgery saw significantly more operations in their respective fields. Similar trends were seen in vascular surgery and surgical oncology. Despite the apparent differences in exposure to subspecialty operations, all students saw equal numbers of hernia repairs and laparoscopic cholecystectomies. Conclusions. While medical students pursuing careers in surgery have equal exposure to general surgery, their anticipated subspecialty field highly correlated with their operative exposure to that field. Thus, medical school surgical rotations appear to highly influence subspecialty choice.
Experimental Study on Triaxial Geogrid-Reinforced Bases over Weak Subgrade under Cyclic Loading

Geogrids have been successfully used to improve soft subgrade and reinforce weak base course by providing lateral confinement. However, uniaxial and biaxial geogrids cannot provide uniform resistance in all directions. A new product termed “Triaxial geogrid” was developed to overcome this limitation. The triaxial geogrid is expected to have a more stable grid structure to provide uniform resistance in all directions as compared with uniaxial and biaxial geogrids. However, the effects of the triaxial geogrids on the performance of reinforced bases have not been well evaluated. In this study, unreinforced and triaxial geogrid-reinforced bases over a weak subgrade were constructed in a large geotechnical testing box (2m x 2.2m x 2m high) at the University of Kansas and tested under cyclic loading. During the tests, the surface deformations and the vertical stresses at the interface between the base and the subgrade were monitored. The test results showed that triaxial geogrids increased percentage of resilient displacement and reduced permanent displacement and vertical stresses at the interface as compared with the unreinforced base.
Serum and follicular fluid (FF) estradiol (E2) levels in ovarian hyperstimulation syndrome (OHSS) during in vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT) conception cycles after pituitary suppression.

Initaial hope that ovarian hyperstimulation syndrome (OHSS) would be less likely to occur after pituitary suppression with gonadotropin releasing-hormone agonists (GnRH-a) has not been substantiated. GnRH-alhuman menopausal gonadotropin (hMG) protocols often lead to OHSS with markedly elevated circulating estradiol (E2) levels in susceptible patients. This study was undertaken to determine whether or not intrafollicular E2 secretion is increased in these cases. Fifty-two in vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT) conception cycles treated with GnRH-alhMG were included in the study. GnRH-a, leuprolide, 0.5 mg, was administered subcutaneously from day 20 of the preceding cycle and the ovaries were stimulated with hMG, 75-225 IU bid intramuscularly, followed by human chrionic gonadotropin (hCG), 5000 IU. Twenty cycles (Group I) were associated with moderate or severe OHSS and 32 cycles (Group II) did not result in OHSS. E2 was measured in the serum on the day of hCG (day 0), on the day of oocyte retrieval (day 2), and at midluteal phase (days 6–8), as well as in the follicular fluid (FF) using a solid-phase direct RIA. Mean serum E2 was significantly higher at all three sampling times in Group I (OHSS) than in Group II. Both the number of follicles and the number of oocytes were also significantly higher in Group I. Mean (±SD) FF E2 concentrations in both groups were similar (367±109 and 364±188) in follicles >15 mm in diameter but were increased in follicles ≤15 mm in diameter in OHSS (479±111) versus non-OHSS (230±32) patients. It appeared that OHSS was a function of an increased number of stimulated follicles as well as a result of altered steroidogenic function at the follicular level.
Pharmaceuticals in the environment.

Pharmaceuticals are the major method of treating human disease in Western medicine, with hundreds of tons being produced, dispensed, and consumed annually. Use of pharmaceuticals in veterinary medicine is also common. After administration, or if they are discarded by patients or health care
A methodology for developing ‘Chainlink’ converters

“Chain circuits or “Chainlink converters” include the Modular Multi-Level Converter (M2LC) [1] and the multilevel Static Compensator (StatCom) [2]. They use large numbers of identical series connected modules, each of which contains a capacitor that can be switched in or out of circuit to present a continually variable voltage at the converter terminals. The technique permits multilevel converters to be constructed without the disadvantages associated with other multilevel topologies and have created major interest for high voltage power transmission applications since complex waveforms can be constructed without the filtering associated with converters utilising PWM. The approach proposed is to operate converter topologies built up from combinations of chain circuits as sets of individual current sources. These are arranged as a matrix form so the current from the input and output terminals are able to circulate through all the chain elements in a subtractive manner. To maintain the capacitor charge level in each chain circuit the net power flow must be zero which can commonly be achieved only for AC to AC or AC to DC power conversion. Additional control is required to trim the operation of the chains to ensure average capacitor voltage in a chain is constrained to a defined level, although the simulation results presented do not include this. An example of a topology that can be derived by this approach is the Matrix Chainlink converter that can directly convert three-phase AC to three-phase AC. A second topology is proposed that will give a AC to 4 quadrant DC converter form that will yield a galvanically isolated DC to DC converter.
Infant sucking in response to variations in schedules of feeding reinforcement.

Abstract Infants aged 1–2 months and 3–4 months were fed from a nipple through which milk delivery could be controlled to conform either to fixed interval or fixed ratios of reinforcement. A variety of fixed-interval schedules were used, with maximum nonreinforced delay of 2.0 sec. Various fixed ratios were also employed, with maximum of 4 sucks per drop of milk. The schedules were linked to negative or positive mouthing pressure in different babies. The principal response to the more sparsely reinforced schedules (FI and FR alike) was a decrease in length of sucking bursts and a concomitant increase in length of pauses between. No scalloping effects were found in the sucking patterns. The older infants were more sensitive to changes in sparseness of schedule. Differential reaction also exhibited itself in sucking arhythmia. The younger infants showed more marked differential reaction to schedules through arhythmia than did the older ones. The findings indicate an increase in alertness and information processing with increased difficulty in obtaining nutriment synchronously with reflex patterns of sucking, since pausing in sucking is associated with greater scanning activity.
HIV protease substrate conformation: modulation by cyclophilin A.

Abstract Cyclophilin A (CyPA), a cytosolic peptidyl-prolyl trans-cis isomerase can accelerate the trans-cis isomerization of Xxx-Pro peptide bonds. One- and two-dimensional 1 H-NMR spectroscopy were used to determine that the heptapeptide Ser-Gln-Asn-Tyr-Pro-Ile-Val, a model peptide of an HIV-1 protease cleavage site in the gag polyprotein of HIV-1, is a substrate for CyPA. Experiments revealed a slow exchange about the Tyr-Pro peptide bond with 30±5% in the cis conformation (pH 1–9). While the interconversion rate is too slow to measure by kinetic NMR methods in the absence of CyPA, these methods, saturation transfer and NOE experiments, established that CyPA enhanced the rate of trans-cis interconversion, a process inhibited by cyclosporin A (CsA). With a substrate:CyPA ratio of 40:1, an interconversion rate of 2.5 s −1 at 25°C was observed.
Taxol partitioning in two-phase plant cell cultures of Taxus brevifolia

An accumulation phase for taxanes was evaluated for its effect on growth and production kinetics in Taxus brevifolia cell cultures. The second phase, tricaprylin, is an eight-carbon triglyceride that favorably partitions taxol secreted into the medium. Cell growth was generally unaffected by the presence of tricaprylin and a moderate increase in taxol synthesis over a 4-week period was observed. Adjustments of the medium pH can be used to obtain significantly higher partitioning (at higher pH), but this adversely affects the cell productivity with a net loss in taxol production for pH values greater than 7.5. Nevertheless, in situ liquid partitioning provides a clean reservoir for taxane separation in otherwise normal cell culture that can also be easily sampled and replaced during a semi-batch or continuous culture.
A Latin-American Articulation of the Holocaust in Jorge Volpi's Oscuro bosque oscuro

I demonstrate in this article that Jorge Volpi's novel Oscuro bosque oscuro takes part in the global conversation about the meaning of the Holocaust by engaging in one of the major contemporary debates in Holocaust studies. I find that this Latin-American appropriation of the topos of the Holocaust does not privilege a Eurocentric, colonial view of world history nor does it trivialize the memory of the victims of the Holocaust. Rather, it adds to the body of Holocaust fictional narratives by preserving memory and combating the recurrence of the Nazi spirit through the fictionalization of Holocaust historiography and the use of fairy tales. Latin American narratives at the turn of the Millennium that appropriate the topos of the Holocaust such as Oscuro bosque oscuro are products of their specific historical place and thus raise awareness of the role of state terror in the massacres of the twentieth century in Latin America.
The chemistry of prohomoerythrinadienone I.

The homoerythrina alkaloids from Cephalotaxusl and Schellhammera2 are proposed to originate from a l-phenethyltetrahydroisoquinoline I, through in vivo phenolic coupling to the prohomoerythrinadlenone II and according to a sequence of transformations analogous to the biosynthesis of the Erythrina alkaloids.3 To date, this biogenetic proposal has not been completely4 demonstrated in the laboratory. An earlier attempt by Kametani5 to prepare the prohomoerythrinadienone II from the N-methylphenethyltetrahydroisoquinoline I (X = Me) failed to yield the dienone II, but instead gave a myriad of products derived from II. During the course of a biogenetic-type synthesis of some homoerythrina alkaloids, we have subjected the trifluoroacetamide of I to various oxidative coupling reactions. We wish to report at this time the first synthesis of the key prohomoerythrinadienone II (X = COCF3) and its facile rearrangement to the homoaporphine skeleton III. This latter transformation constitutes the first synthesis of a homoaporphine alkaloid via a dienone-phenol rearrangement.
Visible Light Knows Who You Are

We examine the feasibility of human identification using purely the ubiquitous visible light. Empowered by the Visible Light Communication (VLC), the identification system consists of VLC-enabled LED lights on the ceiling emitting light beacons, and photodiodes on the floor capturing a continuous stream of shadow maps each corresponding to an LED light. We leverage these shadow maps to localize a user's key boy joints in the 3D space and recognize the user based on the estimated body parameters (e.g., shoulder width, arm length). Preliminary results with 10 participants show 80\% success rate, i.e., correctly identifying 8 participants out of 10. The mean error of the body parameter estimation is 0.03 m. To extend the system to diverse practical settings, we discuss the our plan of incorporating advanced behavioral features to enhance the identification accuracy and robustness.
UHF GaN SSPA for space applications

A new UHF Solid State Power Amplifier (SSPA) has been developed for use in government mobile communications space programs. Predistortion linearization combined with high-voltage gallium nitride (GaN) FET technology allows the simultaneous achievement of both linearity and record high linear efficiency. This SSPA is capable of a peak power of more than 170 watts, but will be operated at a lower power (60 watts) to provide the reliability required for service in space and the linearity needed for WCDMA operation. A power added efficiency (PAE) of greater than 60 % was achieved at this operating point.
Partially Decarbonylated Tetrairidium Clusters on γ-Al2O3: Structural Characterization and Catalysis of Toluene Hydrogenation

Abstract Supported metal clusters were prepared as [Ir4(CO)12] was adsorbed intact fromn-pentane solution onto γ-Al2O3powder that had been partially dehydroxylatedin vacuoat 400°C. The supported clusters were characterized by infrared spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy. The supported [Ir4(CO)12], which was stable after heating in He at temperatures up to 100°C, was decarbonylated to various degrees by treatment in He at temperatures higher than 100°C, with the decarbonylation being complete at 300°C. EXAFS data indicated an average Ir–Ir first-shell coordination number of about 3.0 at an average bond distance 2.67 A at each stage of the decarbonylation, demonstrating that the decarbonylation proceeded without disruption of the tetrahedral cluster frame, ultimately giving Ir4/γ-Al2O3. Chemisorption of hydrogen on the supported Ir4clusters was characterized by an H/Ir atomic ratio of about 0.13, a value much less than that characteristic of larger iridium clusters, which indicates that the supported clusters have reactivities different from those of bulk metallic iridium or iridium particles large enough to have bulklike properties. The [Ir4(CO)12] clusters were partially reconstructed from Ir4/γ-Al2O3by treatment in CO at 150–200°C. The supported tetrairidium clusters at various stages of decarbonylation were found to be catalytically active for toluene hydrogenation at 60°C and atmospheric pressure. The catalytic activity of supported [Ir4(CO)12] was negligible, and the activity increased with increasing decarbonylation, until the degree of decarbonylation reached about 70%, whereupon the catalytic reaction rate became almost independent of the degree of decarbonylation. The data suggest that the last remaining CO ligands have almost no effect on the toluene hydrogenation reaction because the clusters have attained a sufficient degree of unsaturation to provide bonding sites for the reactant ligands.
Low-phytate barley cultivars improve the utilization of phosphorus, calcium, nitrogen, energy, and dry matter in diets fed to young swine

A 28-d experiment was conducted using 45 crossbred barrows with an average initial BW of 9.5 kg and age of 35 d to evaluate low-phytate barley (LPB) mutants (M) M422, M635, and M955, which were hulled, near-isogenic progeny of the normal barley (NB) Harrington and had 47, 66, and 80% less phytic acid, respectively, than NB. A hull-less LPB, M422-H, which was not near-isogenic to the other cultivars, was also evaluated. Apparent nutrient balance, bone measurements, and growth performance were the response criteria evaluated. The barrows were fed the diets to appetite in meal form in individual metabolism crates. Barley and soybean meal were the only sources of phytic acid. Dietary protein supplementation and ME/kg were equalized in all diets. The treatments were diets containing NB, M422, M635, or M422-H without or with added inorganic P (iP), or M955 without added iP. Diets with added iP contained 0.30% available P (aP), the same concentration of aP provided by the diet containing M955 without added iP. There were linear increases (P < or = 0.02) in ADG, G:F, metacarpal and radius bone strength, and fat-free dry weight, and in the absorption and retention (g/d and % of intake) of P and Ca with increasing dietary concentration of aP from the near-isogenic cultivars NB, M422, M635, or M955 without added iP. There were linear decreases in the grams (P < or = 0.02) and percentages (P < 0.001) of P and Ca excreted per day with increasing dietary concentration of aP without added iP. There were no responses for N or energy balance. Growth performance and bone response criteria did not differ for barrows fed the diet containing M955 or the near-isogenic diets containing NB, M422, or M635 with added iP. However, barrows fed the diet containing M955 had greater (P < or = 0.02) percentages of P, N, and energy absorption and retention, Ca absorption, and DM digestibility and had less (P < or = 0.02, g/d and %) excretion of P, N, energy, and Ca (g) per day than barrows fed the diets containing the near-isogenic NB or LPB cultivars with added iP. When dietary aP was equalized with iP, the excretion of P in feces plus urine (g/d) was reduced by 20.2, 27.9, and 44.6%, respectively, in barrows fed the diets containing M422 + iP, M635 + iP, or M955 compared with barrows fed the diet containing NB + iP. Energy utilization did not differ for barrows fed the diets containing hulled or hull-less LPB when ME/kg was equalized with lard. In conclusion, the apparent utilization of P and Ca, the bone strength and fat-free dry weight, and growth performance increased with increasing dietary concentration of aP provided by LPB, in association with linear decreases in P and Ca excretion. Barrows fed the diet containing M955 also had greater utilization and less excretion of P, Ca, N, energy, and DM than barrows fed the diets containing the near-isogenic NB or LPB cultivars with added iP to equalize aP at 0.30%.
Narrating Neighborhood: Denying Young Women’s Public Voices About Violence

This paper describes a youth-centered activist project with a group of young women in Brooklyn, NY, and the controversy surrounding it. In 1999 the young women created a neighborhood mural with anti-violence themes. Within 6 months of the mural’s dedication, the mural was whitewashed by the corporate owner of the mural wall. Using content and discourse analysis of archival materials, organizational documents, and ethnographic fieldnotes from participant observation, I argue that the teen women’s representations of violence were denied through the shifting understandings of their ages and assumptions about conflict resolution strategies. I offer reflections on the need for careful planning and reflection in youth participatory projects and the meanings of success and social change in these projects.
Enterohemorrhagic Escherichia coli in the United States

Escherichia coli O157:H7, the documented cause of over 100 outbreaks of human disease in the United States since it emerged as an epidemic cause of foodborne illness in 1982, is a textbook illustration of today's emerging microbial pathogen. Its ‘emergence’ apparently is associated with genetic changes in the organism, changes in food production and distribution, human behavior, and changes in disease reporting requirements that brought increased recognition. The largest documented outbreak in the United States, with over 700 illnesses and four deaths, occurred in 1993 in the western United States. The vehicle of transmission was the same as in 1982 — contaminated hamburger, quickly and widely distributed through ‘fast food’ restaurant chains. This paper will examine each of these contributing factors, trace the emergence of E. coli O157:H7 in the United States, discuss methods for identifying vehicles of epidemic and sporadic transmission, and control measures that are being taken. E. coli typically are benign inhabitants of the human and animal gut, and are so ubiquitous that their detection is used to monitor fecal contamination and sewage treatment effectiveness. But not all E. coli are benign. Several dozen have been recognized as human pathogens and are associated with at least five different pathogenic mechanisms. Some, like the classic enteropathogenic E. coli (EPEC) strains, have enteroadhesive genes ( eae ) on their chromosomes that are essential for the production of the characteristic attaching and effacing lesions. Enterotoxigenic (ETEC) strains produce toxins and enteroinvasive strains possess invasive qualities [1]. Molecular genetic studies indicate that E. coli O157:H7 evolved from an EPEC progenitor that acquired the Shiga-toxin gene ( stx ) [2]. Having this gene and expressing the toxins, classifies E. coli O157:H7 as a member of the Shiga-toxin producing E. coli (STEC). The gene is essentially indistinguishable from that on the chromosome of Shigella dysenteriae …
“Winter sports under a summer sun”: the marketing of Sun Valley ski resort in the 1930s

Purpose – The purpose of this paper is to describe the growth of the early ski market and the marketing strategies that the Union Pacific Railroad took in promoting Sun Valley ski resort, one of the most popular early destination ski resorts in the USA.Design/methodology/approach – The paper uses primary and secondary source material, including ski periodicals, national magazines and the manuscript collection of W. Averell Harriman, the Chairman of the Union Pacific Railroad during the creation of Sun Valley.Findings – This paper finds that Sun Valley pioneered the western ski vacation by conducting careful market research into not only the snow and weather conditions of western mountains, but also into the habits and economic potential of skiers and winter tourists.Originality/value – Scholarly work on skiing has primarily looked at the sport from the social and cultural perspective of skiers. Work on entrepreneurial objectives of ski resort designers has largely focused on the period after the Second Wo...
HYPERTENSIVE DISORDERS, DIABETES MELLITUS, AND ANEMIA: Three Common Medical Complications of Pregnancy

Hypertensive disorders, diabetes mellitus, and anemia are three common medical complications of pregnancy. In many cases, primary care physicians manage them. The understanding of these conditions and recommendations for their treatment are in constant evolution. Care for patients with these problems requires a working knowledge of current information. This article reviews the current knowledge about and treatment of these three disorders. HYPERTENSIVE DISORDERS OF PREGNANCY Hypertensive disorders are a common complication of pregnancy, affecting approximately 10% of all pregnancies in the United States.40 Pre-eclampsia occurs in approximately one fourth of these pregnancies, but the occurrence of preeclampsia has been estimated by some investigators to be as high as 7% of pregnancies not ending in first-trimester spontaneous abortion.49 Chronic hypertension and transient hypertension of pregnancy account for the remainder of cases. These disorders carry significant risk for fetal and maternal morbidity and mortality. Hypertensive disease is the second leading cause of maternal mortality in