cssi/SciSciGPT-SciSciNet huggingface dataset:
On the relative execution times of distributed protocols

A formalism for comparing the average execution time of distributed protocols is provided. The comparisons are made independently of the properties of the network on which the protocols are executed. The formalism takes into account computation time, the time to transfer information, the time spent by a site waiting to synchronize with other sites, and the overlap among them. A framework in which the information transfer and synchronization requirements of a protocol are separately and explicitly specified is developed. A knowledge formalism is used to specify the protocol's specification requirements. Transformations on protocols which may change the synchronization structure, the information transferred, or the amount of local computation are defined. It is shown that, if a sequence of such transformations can be applied to a protocol to obtain another protocol, the final protocol runs at least as fast as the initial. Two notions of comparison, containment and reducibility, are given, and their properties are explored. Several protocols, including those for atomic commitment and snapshot recording, are analyzed to illustrate the technique. >
Nonclassical Brock-Mirman Economies

We show that monotone methods, especially, those based on lattice theory and lattice programming can produce results, e.g., on the monotonicity of the optimal programs, as well as on the existence of fixed points, consistent with the current macroeconomics literature, in the absence of continuity, differentiability and concavity. We illustrate the use and power of the lattice theory techniques in two simple and very useful models. First, the Brock-Mirman growth model is studied in a nonclassical setting. Here all the assumptions of the original model are made except that the production function is allowed to be non-concave. The second model is an extension of the Brock-Mirman model that goes beyond the planner's solution and allows for decentralized decisions in equilibrium.
A new multicast routing algorithm in hierarchical satellite networks

A new multicast routing algorithm is introduced for multi-layered satellite networks, which include GEO, MEO, and LEO layers. This scheme aims to minimize the total cost of multicast trees in the satellite network. Multicast trees are constructed and maintained in the dynamic satellite network topology in a distributed manner. Simulation results are provided to evaluate the performance of this scheme in terms of end-to-end delay and multicast tree cost.
Backlash to the Future? From Roe to Perry

Does a judicial decision that vindicates minority rights inevitably give birth to a special kind of backlash, a more virulent reaction than legislation achieving the same result would produce? We examine this question with respect to Roe v. Wade, so often invoked as the paradigmatic case of court-caused backlash, and with the pending marriage cases in mind. As we have shown, conflict over abortion escalated before the Supreme Court ever ruled in Roe, driven by movements struggling over legislative reform and Republican Party efforts to recruit voters historically aligned with the Democratic Party. These and other features of the abortion conflict suggest that the Court's decision in Roe was not the abortion conflict's sole or even its principal cause.When change through adjudication or legislation threatens the status quo, it can prompt counter-mobilization and "backlash." We do not doubt that adjudication can prompt backlash. But we do doubt that adjudication is distinctively more likely than legislation to prompt backlash and that the abortion conflict illustrates this supposed property of adjudication. Advocates concerned about these questions have to make in-context and on-balance judgments that consider not only the costs but also the benefits of engagement.
Women and Substance Use Disorders

Fowler, D. (2007). The extent of substance use problems among women partner abuse survivors residing in domestic violence shelter. Family & Community Health, (Supplement 1, January–March 2007), S10...
Factors Affecting Estrogen-Induced LH Release in the Cow

ABSTRACTSixexperimentswereconductedtostudythemechanismscontrollingestrogen-inducedlutein-izing hormone (LH) release inthe cow. Estradiol-l7ii (E2) induced arelease ofLHinovariiec-tomized cows atdoses ranging from 0.25-10.00 mgandestrone(E,)waslesseffectivethanE2.Exogenous progesterone (P4), administered s.c. inasilicone rubber implant forperiods of2-9dayspriortoE2injections,didnotinhibittheE2-inducedLHreleaseevenwhenaverylowdose(0.25 mg)ofE2was given. However, when acorpus luteum (CL) waspresentandendogenousP4wasmorethan1ng/ml,E2didnotinduceanLHrelease.Possiblemechanismsforthisdiscrepancybetween the effects ofexogenous and endogenous P4are discussed. Suckling and/or lactationinhibited the E2-induced LH release foratleast 2weeks postpartum. This inhibition may partiallyexplain postpartum anestrus.INTRODUCTIONInjections of estrogen in the cow consist- ently cause anincrease inluteinizing hormone (LH) similar to the spontaneous rise observedatestrus.Thisestrogen-induced LH release has been noted in both ovariectomized (HobsonandHansel,1972;Shortet
MCHC in intravascular hemolysis.

Elevations in the MCHC to greater than 50.0 g/dl were reported in two patients with acute intravascular hemolysis due to clostridial septicemia. This increase was likely spurious due to the presence of extracellular hemoglobin
Effect of coronary vasodilation on ventricular fibrillation threshold: Role of exogenous vasodilators and perfusion conditions

Even without myocardial ischemia, coronary blood flow (CBF) constitutes a major determinant of ventricular fibrillation threshold (VFT). To clarify whether abnormal distribution of normal or increased CBF plays any additional role, 14 open-chest chloralose-anesthetized dogs with fixednormalized heart rate, cardiac output, and systemic arterial pressure and separate servocontrolled left main coronary artery perfusion were studied as follows: VFT was determined first with coronary perfusion pressure (CPP) set at systemic level (80 mm Hg). Then CBF index was fixed at control levels (134.0 ± 9.5 ml/min · 100 gm−1 LV) and coronary vasodilation was induced by intracoronary infusion of adenosine until CPP decreased to 49.0 ± 2.0 mm Hg. Myocardial O2 consumption, LV pressure, LV dpdt, and surface ECG remained unchanged. However, VFT decreased in all trials by about 45% (p < 0.001). When CPP was reset to 80 mm Hg while maintaining vasodilation, CBF index increased by 90% to 255.4 ± 15.4 ml/min · 100 gm−1 LV and VFT by 26% (p < 0.005) from control. Yet these VFT increases in response to intraluminal pharmacologic vasodilation were about 19% (p < 0.002) lower than expected for similar CBF index increases occurring physiologically. We conclude that intraluminal coronary vasodilation not matched by appropriate CBF increase results in substantial decrease of VFT. Moreover, at comparable increase of CBF, spontaneous physiologic vasodilation is more effective than intraluminal pharmacologic coronary vasodilation in increasing VFT.
p75NTR Antagonistic Cyclic Peptide Decreases the Size of β Amyloid-Induced Brain Inflammation

Amyloid beta (Aβ) was shown to bind the 75 kD neurotrophin receptor (p75NTR) to induce neuronal death. We synthesized a p75NTR antagonistic peptide (CATDIKGAEC) that contains the KGA motif that is present in the toxic part of Aβ and closely resembles the binding site of NGF for p75NTR. In vivo injections of Aβ into the cerebral cortex of B57BL/6 mice together with the peptide produced significantly less inflammation than simultaneous injections of Aβ and a control (CKETIADGAC, scrambled) peptide injected into the contralateral cortex. These data suggest that blocking the binding of Aβ to p75NTR may reduce neuronal loss in Alzheimer’s disease.
Tunneling and transport problems for a quantum mechanical Brownian particle

The Kanai model of a quantum mechanical Brownian particle is used to examine the effect of interactions between particles and their environment. Random forces cause the thermalization of the particle. Reflection of a particle from a step barrier is analyzed. The problem of tunneling of the Brownian particle through a rectangular barrier is solved. Finally, a solution for a Brownian particle in a box is presented.
Social Action Research: Influencing Providers and Recipients of Health and Mental Health Care for Lesbians

From 1994 through 1997, the Lesbian Health Care Project of Western New York (LHCP), a feminist social action research project, gathered region-specific information about lesbians' physical and mental health care. The project conducted a community survey, community focus groups, and a provider survey and developed and distributed a community resource book/directory of providers. This article describes the project and its findings and discusses social action strategies and implications for practice.
Theoretical calculations of the electronic structure and optical transitions of UF6 and UF5

Abstract The self-consistent-field Xα scattered wave (SCF Xα SW) approach to molecular orbital theory has been applied to the UF 6 molecule and to an assumed structure of UF 5 (in C 4v symmetry) to determine their electronic structures and optical transitions.
A device for generation and presentation of modulated light stimuli

Abstract A device is described which enables generation and presentation of light stimuli modulated by various wave forms and frequencies. The system consists of a solid state amplifier with emitter follower circuit which amplifies the output of a wave form generator to drive light sources mounted in goggles worn by the subject. Where color and low light intensity are acceptable, light-emitting diodes should be used as light sources because of their accurate reproduction of input wave forms. If high intensity is necessary, small incandescent bulbs can be used with certain limitations in frequency, wave form response and color due to filament warm-up and cool-down time. Mounting the light sources in goggles with individual eye cups maintains constant light source-to-eye geometry, permitting stimulation during drowsiness or sleep and eliminates extraneous visual stimuli.
Gravity-driven instability of a thin liquid film underneath a soft solid

The gravity-driven instability of a thin liquid film located underneath a soft solid material is considered. The equations and boundary conditions governing the solid deformation are systematically converted from a Lagrangian representation to an Eulerian representation, which is the natural framework for describing the liquid motion. This systematic conversion reveals that the continuity-of-velocity boundary condition at the liquid-solid interface is more complicated than has previously been assumed, even in the small-strain limit. We then make clear the conditions under which the commonly used simplified version of this boundary condition is valid. The small-strain approximation, lubrication theory, and linear stability analysis are applied to derive an expression for the growth rate of small-amplitude perturbations. Asymptotic analysis reveals that the coupling between the liquid and solid manifests itself as a lower effective liquid-air interfacial tension that leads to larger instability growth rates. Although this suggests that it is more difficult to maintain a stable liquid coating underneath a soft solid, the effect is expected to be weak for cases of practical interest.
Entrepreneurial orientation and performance in young firms: The role of human resource management:

This article examines the effects of managerial practice and philosophy variables – high-performance work systems (HPWS) and partnership philosophy – on the relationship between entrepreneurial ori...
Oservations of deformation induced substructure in A1-A12O3 SAP-type dispersion-strengthened alloys

Abstract The deformation induced substructure of several recrystallized Al-Al 2 O 3 SAP-type alloys has been studied utilizing transmission electron microscopy. Bulk strip specimens of AT-400 and MD-2100 alloys were subjected to various degrees of rolling and tensile deformation at room temperature. It was found that rolling deformation eventually led to the formation of a ragged cell structure through a series of intermediate steps: 1. (1) isolated dislocation tangles initially formed around groups of closely spaced oxide particles; 2. (2) these isolated tangles developed generally throughout the alloys with increasing deformation; 3. (3) the groups of tangles began to connect up and form very diffuse cell walls; 4. (4) at high deformations the cell walls became denser and more discrete. The cells were observed to form at later stages of deformation and to attain a smaller minimum size than the cells formed in high purity single-phase aluminum rolled at room temperature. Tensile deformation of the AT-400 alloy produced no semblance of a cell structure. Instead, a more uniform distribution of heavily tangled and jogged dislocations was formed. This structure appeared to be the final dislocation configuration before fracture of the tensile specimens. Sequential photography of specimens deformed in the microscope provided observations of dislocation-particle interactions in these alloys. These observations indicate that initial yielding may be due to particle fracture, in accordance with the Ansell-Lenel model for the yielding of dispersion-strengthened materials.
A concise synthesis of (-)-lasonolide A.

Lasonolide A is a novel polyketide displaying potent anticancer activity across a broad range of cancer cell lines. Here, an enantioselective convergent total synthesis of the (−)-lasonolide A in 16 longest linear and 34 total steps is described. This approach significantly reduces the step count compared to other known syntheses. The synthetic strategy utilizes alkyne-bearing substrates as core building blocks and is highlighted by stitching together two similarly complex halves via a key Ru-catalyzed alkene–alkyne coupling and macrolactionization.
Specific Language Impairment and Executive Functioning: Parent and Teacher Ratings of Behavior

Purpose The current study used the Behavior Rating Inventory of Executive Function—Preschool Version (BRIEF–P; Gioia, Espy, & Isquith, 2003), a rating scale designed to investigate executive behavi...
Newborn screening for congenital cytomegalovirus: Options for hospital-based and public health programs

Abstract Background Congenital cytomegalovirus (CMV) infection is a leading cause of sensorineural hearing loss (SNHL) and developmental disability in children. Early identification of infected children through screening could allow for early intervention and improvement in functional outcomes among the subset who develop sequelae. Objectives To outline potential options and strategies for screening newborns for congenital CMV infection and to discuss barriers to screening and data needs to inform future policy decisions. Study design Commentary based on the literature and expert opinion on newborn dried blood spot screening, newborn hearing screening/Early Hearing Detection and Intervention (EHDI) programs, and congenital CMV. Results Although no population-based screening for congenital CMV is underway, pilot newborn screening studies using a variety of assays with urine or dried blood spot specimens are underway. Challenges to screening are both practical—uncertain sensitivity of blood spot assays suitable for large-scale screening and lack of infrastructure for collection of urine specimens; and evidentiary—the need to demonstrate improved outcomes and value of screening to offset the expense and potential adverse psychosocial consequences for children and families whose children require periodic monitoring but never develop sequelae. Conclusions Screening for congenital CMV infection is a potentially important intervention that merits additional research, including the logistical feasibility of different screening options and psychosocial consequences for families.
Drug metabolism by the human fetus.

A review of the literature that pertains to drug biotransformation in human fetal tissues reveals that, in spite of several publications in this comparatively new area of research, only very limited definitive information is currently available. The large majority of the studies performed have dealt with the cytochrome P-450-dependent microsomal mono-oxygenase systems and for several of the common drug metabolising reactions, very little or no data are available at this time. Some of the more important data that have emerged include observations that important bioactivation reactions can be demonstrated in human fetal tissues obtained during the period of late embryogenesis (high susceptibility to chemical dysmorphogenesis) and that the human fetal adrenal gland possesses considerable capacity to catalyse several important oxidation-reduction reactions. From the data available to date, it would appear that, in most instances, the biotransformation of drugs in the human embryo and fetus would not affect maternal plasma concentrations significantly. From the viewpoint of parameters of the pharmacokinetics of parent drug (or other xenobiotic) substrates under steady-state conditions, human fetal drug metabolism probably is of little consequence in most cases, although exceptions may exist. Pharmacokinetic parameters observed after isolated exposure, however, are very likely to be affected, perhaps markedly, in some instances. The demonstrated capacity of human prenatal tissues and cells to generate reactive intermediary metabolites, including those that produce mutations, has attracted the greatest attention recently. This capacity may be associated with extremely important adverse reactions to drugs and other environmental chemicals. Such adverse responses include transplacental mutagenesis, carcinogenesis, dysmorphogenesis, and perhaps several other undesirable effects. Although far from conclusive, the data tend to suggest that humans and subhuman primates may be more vulnerable than the smaller common experimental animals to the toxic effects of foreign organic chemicals during prenatal life. These factors should be weighed whenever exposure of pregnant women to such agents (e.g. via drug administration) is contemplated.
The Design, Characterization, and Implementation of a One Micron Lithography Process in a High Volume Manufacturing Line

The design of a manufacturable, cost effective one micron lithography process requires locating and optimizing the largest manufacturing window of focus, exposure, and bias for each critical cd layer. Special attention must be paid to the resist and thin film coupling effects on critical dimensions and resist clear point, Eo. Similar characterization and optimization must be performed for registration control as well. This paper explores optimization techniques that proved successful in determining the process parameters which yield the best manufacturing tolerances. Distribution centering techniques will also be discussed as well as the key approaches to implementing a process which does not require any lot dependent adjustments or test wafers. The case for non-adjustment processing can not be overstated for if the process is constantly "tweaked" for exposure or offsets, stability and control is impossible and so is low cost, high output production. The steps to use in designing, characterizing and controlling a no-adjust lithography process are outlined in this paper.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Types and duration of symptoms prior to diagnosis of invasive or borderline ovarian tumor

Abstract Objective. The objective was to describe and compare types and duration of symptoms among women with invasive versus borderline ovarian tumors. Methods. Cases were women, ages 20–69 years, diagnosed with invasive (616) and borderline (151) epithelial ovarian tumors from 1994 to 1998. Symptoms were obtained using a standardized in-person interview. Differences in types and duration of symptoms, time to diagnosis after consulting a physician, and primary reason for diagnosis by invasive/borderline status and histologic type were determined using bivariate and regression analyses controlling for age. Results. Borderline and invasive cases reported similar types of symptoms. However, borderline cases were twice as likely to report not having had symptoms as invasive cases (16 vs 8%, P = 0.005). Prediagnostic symptom duration was longer among borderline versus invasive cases (median: 6 vs 4 months, P P = 0.001). Invasive cases were more likely to be diagnosed because of symptoms (62 vs 48%, P = 0.002). Conclusions. Because most (90%) women with ovarian tumors have symptoms and median symptom duration is 4 months, greater awareness of symptoms by women and physicians is needed for the earlier detection of ovarian tumors. The lesser likelihood of being detected by routine examination and the shorter symptom duration for invasive versus borderline cases underscores the need for effective screening and preventive strategies.
Temperature influences on water permeability and chlorpyrifos uptake in aquatic insects with differing respiratory strategies

Aquatic insects have evolved diverse respiratory strategies that range from breathing atmospheric air to breathing dissolved oxygen. These strategies result in vast morphological differences among taxa in terms of exchange epithelial surface areas that are in direct contact with the surrounding water that, in turn, affect physiological processes. This paper examines the effects of acute temperature shifts on water permeability and chlorpyrifos uptake in aquatic insects with different respiratory strategies. While considerable differences existed in water permeability among the species tested, acute temperature shifts raised water influx rates similarly in air-breathing and gill-bearing taxa. This contrasts significantly with temperature-shift effects on chlorpyrifos uptake. Temperature shifts of 4.5 degrees C increased 14C-chlorpyrifos accumulation rates in the gill-bearing mayfly Cinygma sp. and in the air-breathing hemipteran Sigara washingtonensis. However, the temperature-induced increase in 14C-chlorpyrifos uptake after 8 h of exposure was 2.75-fold higher in Cinygma than in Sigara. Uptake of 14C-chlorpyrifos was uniformly higher in Cinygma than in Sigara in all experiments. These findings suggest that organisms with relatively large exchange epithelial surface areas are potentially more vulnerable to both osmoregulatory distress as well as contaminant accumulation. Temperature increases appear more likely to impact organisms that have relatively large exchange epithelial surface areas, both as an individual stressor and in combination with additional stressors such as contaminants.
Open innovation networks between academia and industry: an imperative for breakthrough therapies

Open innovation networks between academia and industry: an imperative for breakthrough therapies
Noninvasive MR imaging of magnetically labeled stem cells to directly identify neovasculature in a glioma model

Bone marrow-derived endothelial precursor cells incorporate into neovasculature and have been successfully used as vehicles for gene delivery to brain tumors. To determine whether systemically administered Sca1+ bone marrow cells labeled with superparamagnetic iron oxide nanoparticles can be detected by in vivo magnetic resonance imaging in a mouse brain tumor model, mouse Sca1+ cells were labeled in vitro with ferumoxides-poly-L-lysine complexes. Labeled or control cells were administered intravenously to glioma-bearing severe combined immunodeficient (SCID) mice. Magnetic resonance imaging (MRI) was performed during tumor growth. Mice that received labeled cells demonstrated hypointense regions within the tumor that evolved over time and developed a continuous dark hypointense ring at a consistent time point. This effect was not cleared by administration of a gadolinium contrast agent. Histology showed iron-labeled cells around the tumor rim in labeled mice, which expressed CD31 and von Willebrand factor, indicating the transplanted cells detected in the tumor have differentiated into endothelial-like cells. These results demonstrate that MRI can detect the incorporation of magnetically labeled bone marrow-derived precursor cells into tumor vasculature as part of ongoing angiogenesis and neovascularization. This technique can be used to directly identify neovasculature in vivo and to facilitate gene therapy by noninvasively monitoring these cells as gene delivery vectors.
Rat strains differ in susceptibility to Ureaplasma parvum-induced urinary tract infection and struvite stone formation.

ABSTRACT Individuals with struvite uroliths are susceptible to recurrent urinary tract infections (UTI), sepsis, and renal disease. Unfortunately, little is known about the host-specific factors that predispose to this disease. In order to develop a rodent model that can address this problem, we inoculated female Fischer 344 (F344), Lewis (LEW), Sprague-Dawley (SD), and Wistar (WIS) rats with a host-adapted strain of Ureaplasma parvum. Animals were necropsied at 2 weeks postinoculation; 100% of F344, 42% of SD, 10% of LEW, and 10% of WIS rats remained infected. Severe bladder lesions and struvite calculi were seen in 64% of F344 rats; in other rat strains, bladder lesions were mild or absent. F344 rats with struvite uroliths had the highest urinary levels of proinflammatory cytokines, such as GRO/KC, interleukin-1α (IL-1α), and IL-1β. F344 rats without struvite stones at necropsy had milder bladder lesions and significantly lower urinary levels of proinflammatory cytokines but a more prominent inflammatory response than did other rat strains. Based on our results, struvite stone formation is linked to a robust inflammatory response that does not resolve UTI but instead promotes damage to surrounding tissues.
Improved fax transmission of halftone images

Improved fax transmission of halftone imagesHei Tao Fung and Kevin J. ParkerDepartment of Electrical EngineeringUniversity of RochesterRochester, New York 14627ABSTRACTThe conventional method for sending halftone images via facsimile machines isinefficient. The ToneFac algorithm previously proposed improves the efficiency of halftoneimage transmission. ToneFac represents a halftone image by mean block values and an errorimage. To improve on ToneFac, this paper proposes additional processing techniques:searching for the error-minimizing gray value for each block, quantization and coding ofblock values, bit switching, which transforms the error image into a more compressibleimage, optimal block sizing, and spurious dot filtering, which removes perceptuallyinsignificant dots. The new algorithm is compared to other methods including adaptivearithmetic coding, and is shown to provide improvement in bit rate.Keywords: facsimile, compression, coding, transmission, halftone.1. INTRODUCTIONFacsimile machines transmit text and line arts efficiently. Using Group 3 and Group4 devices, a compression ratio of 10 to 20 can be easily reached14. Yet, for halftoneimages, expansion rather than compression of data often results because there are many shortruns of white pixels and black pixels. The Huffman codes have not been designed for thistype of run statistics. One may transmit the data without compression, but the spatialredundancy in the halftone images is left unutilized. Other entropy coding schemes such asadaptive arithmetic coding5 are applicable, but they are not standard for facsimile machines.Also, they do not perform well on halftone images with blue noise characteristics. Anotherapproach is to encode the gray scale image using a lossy coding scheme such as the DCT-based JPEG6 and provide halftoning at the receiver. However, it can be shown that thehalftone thus generated is different from the halftone generated using the original gray scaleimage.In the ToneFac algorithm7, a mask is assumed to be known to both the transmitterand the receiver, and the halftone images are generated using this mask. A gray scale imageto be sent as a halftone image is divided into non-overlapping blocks. For each block, theblock value, which is the mean gray value (or the median gray value) according to ref. 7, issent. An error image, which records the difference in the desired halftone and the halftoneconstructed using the block values, is also transmitted. The error image is encoded using theGroup 3 or Group 4 facsimile standard coding scheme3'4.This paper proposes some techniques to improve on the efficiency of ToneFac. Theresulting compression ratios improve by a factor of 2 over those obtained with the earliermethods.
Looking through Hägerstrand’s dual vistas: towards a unifying framework for time geography

Abstract The publication of Hagerstrand’s seminal paper on the conceptual framework of classic time geography in 1970 has inspired a steady stream of research in multiple fields related to transportation, planning, geography, ecology, environmental science, and public health. Just like most other scholarly work, Hagerstrand’s time geography has also received its fair share of criticism from scholars of different philosophical persuasions. In response to these criticisms, Torsten Hagerstrand himself made significant efforts to extend his original framework on time geography to move beyond paths, constraints, prisms, and projects during the last 30 years of his life. Yet these diverse later efforts by Hagerstrand are still scattered in the literature and have not exerted as much influence on time geography research as Hagerstrand’s (1970) original paper. The goal of this paper is to take stock of the major extensions Hagerstrand made for time geography between 1970 and 2004. By linking Hagerstrand’s shifting views on time geography to the ancient Greek conceptualization of space and time, a unifying framework based upon the Greek manifolds of space and time is proposed for time geography. The new framework not only restores the multiple dimensions of time geography as Hagerstrand envisioned later in his life, but also links the diverse ongoing time geography research efforts to themes derived from the framework. Future research challenges in time geography are also discussed.
Public memorializing in postmodernity: The Vietnam veterans memorial as prototype

This essay argues for a reading of the Vietnam Veterans Memorial as a postmodern discourse. Beginning with a contrast of modernist and postmodern rhetorics of architecture, the authors suggest that the Memorial reflects the typical gestures of postmodern architecture. Moreover, they suggest that a consideration of the Vietnam Veterans Memorial as a postmodern discourse accounts for differences among other critical accounts, highlights the Memorial's political stance, and bears implications for a postmodern monumentality. The essay concludes with a discussion of the critical assumptions that are placed at issue in a postmodern reading.
Effect of mineral dust aerosols on the photolysis rates in the clean and polluted marine environments

[1] This study examines the importance of spectral optical properties of mineral dust in calculations of photolysis rates in clean and polluted marine environments. A set of optical characteristics was computed with Mie theory using data on the size distribution and composition of mineral dust from recent experimental and modeling studies. These models were incorporated into the National Center for Atmospheric Research tropospheric ultraviolet-visible radiation transfer code. The 13 analyzed photolysis reactions were classified into three groups according to their photolytic wavelengths and the vertical profile of J values in the aerosol-free atmosphere. The photolysis reactions of O3(O1D), NO2, and NO3(NO) were selected as representative of groups I, II, and III, respectively. We find that depending on its properties, dust causes either a decrease or an increase in the spectral actinic fluxes relative to the aerosol-free condition. The wavelength range in which the changes in actinic fluxes are negative becomes broader as the amount of dust load increases, a dust size distribution is shifted to coarse size mode, and the iron oxide content in dust aggregates increases. Changes in actinic fluxes also depend on the sun position (time of the day) and an altitude considered. As a result, dust exerts the differing impact on J values of the three photolytic groups. The diurnal cycle of dust-affected J values of a given group is similar among the differing size distribution and dust compositions, but changes in J values vary by a factor of 1.5–2. For a given content of iron oxide, the largest changes are caused by the size distributions that are shifted to the fine size mode. A change in J values of groups I and II caused by the varying amount of iron oxide in dust aggregates (from 1% to 10%) is negative in and below the dust layer. In contrast, J values of group III increase in the presence of low absorbing dust (with 1% of iron oxide), but they decrease with increasing dust absorption. Our results indicate that the dust composition not only will be needed to accurately model a decrease in J values of groups I and II but also to determine a correct sign and value of changes of J values of group III. In the case of dust mixed with pollution, we find that the external mixing of dust and black carbon causes somewhat larger changes in J values compared to the internal mixing of these species. We conclude that regional differences in size and composition of mineral dust as well as related changes in the vertical profile and diurnal cycle of actinic fluxes and J values should be taken into account if more realistic assessments of the dust impact on photochemistry through photolysis are to be achieved.
Characterization of protein kinase C activity in interferon gamma treated murine peritoneal macrophages

Macrophage activation for tumoricidal and microbicidal functions can be achieved in part by treatment with recombinant interferon gamma (IFN gamma) in vitro. We have previously demonstrated that IFN gamma treatment of murine peritoneal macrophages results in a two- to five-fold increase in the activity of Ca++, phospholipid dependent protein kinase C (Hamilton et al., J. Biol. Chem., 260:1378, 1985). We now report that this effect was not dependent upon continuing protein synthesis since treatment with cycloheximide under conditions where normal protein synthesis was inhibited by greater than 95% had no effect upon the development of increased enzyme activity. Examination of Ca++ and phospholipid requirements revealed no differences between enzyme isolated from control or IFN gamma treated cells. Similarly, protein kinase C from control and IFN gamma-treated cells could not be distinguished in terms of the diacylglycerol (DG) or phorbol diester (PMA) concentration required for stimulation of activity. Kinetic analysis of the ATP (as substrate) concentration dependence revealed that both control and treated enzyme preparations (either basal or stimulated) had comparable Km values. Maximum velocity (Vmax) was increased both by IFN gamma treatment and also by stimulation with DG or PMA. The major difference which could be discerned between protein kinase C derived from control versus IFN gamma-treated macrophages was the magnitude of the response to DG or PMA; IFN gamma treatment increased the stimulation index (i.e., ratio of basal to stimulated activity) by a factor of two to four fold. These results suggest that IFN gamma treatment leads to reversible modulation of existing protein kinase C resulting in increased catalytic efficiency when exposed to an appropriate stimulant.
On the oligosaccharide moiety of angiotensin-converting enzyme

Abstract Two glycopeptide fractions in a pronase digest of rabbit pulmonary angiotensin-converting enzyme were resolved by gel filtration. GP-I, the minor component (∼1 mole/mol enzyme) contained mannose, galactose, glucose N -acetylglucosamine, N -acetylgalactosamine and sialic acid in an approximate molar ratio of 1:5:3:4:1:2 and molar equivalents of aspartic acid, threonine and serine. GP-II, the major oligosaccharide unit (∼ 12 moles/mol enzyme, ∼ 90% of total carbohydrate), contained fucose, mannose, galactose, N -acetylglucosamine, sialic acid and aspartic acid in a molar ratio of 1:4:4:4:1:1. Although accounting for about one-quarter of the weight of the enzyme, GP-II did not compete with the intact glycoprotein for binding to goat antienzyme antibodies. Some structural features of GP-II were deduced by periodate oxidation and digestion with various glycosidases.
Interactions of WASp Nucleation Promoting Factors with Fission Yeast Arp2/3 Complex

Arp2/3 complex mediates the formation of actin filament branches during endocytosis and at the leading edge of motile cells. The minimum requirements to reconstruct Arp2/3 complex mediated nucleation in vitro are actin monomers, a nulceation promoting factor (NPF), mother actin filaments and Arp2/3 complex. Although several reaction parameters have been measured, the pathway of branch formation from these reactants is still ambiguous owing to missing parameters. We use the CA motifs from the C-terminus of the fission yeast NPF, Wsp1p, to investigate the effect of actin filaments on the interaction between Arp2/3 complex and VCA. Actin filaments increase the affinity of CA for Arp2/3 complex 6-fold (Kd=300nM without filaments and 50nM with filaments). Equilibrium binding experiments and isothermal titration calorimetry both indicate that Arp2/3 complex binds two CAs with different affinities. These results show that the mechanism of Arp2/3 complex mediated actin nucleation involves CA binding to two different sites.
Geochemical Investigations of Athabasca Oil Sands: ABSTRACT

Analyses were performed to evaluate the organic composition and the mineral content of the McMurray oil sands in northeastern Alberta, Canada. The samples came from the Abasand Quarry near McMurray and from three bore holes, drilled along a southwest-northeast cross section in the Fort MacKay and Bitumount area. The bitumen content is related to the particle size of the rock. Impregnation is not restricted to one particular sediment type in the McMurray formation. For example, sandstone zones in the Bitumount core were found to contain as much as 17 per cent organic material soluble in methylene chloride; the bitumen content of the shale layers is lower. The elementary composition of the organic material was found to be uniform throughout the entire 246-foot section of the McMurray formation in the core. An organic sulphur content of approximately 5 per cent extends throughout the core. The aromatic character of the bitumen was shown by spectroscopic methods of analysis. The bitumen contains End_Page 1253------------------------------ approximately the same amount of those hydrocarbons that may be recovered by n-heptane elution on silica gel columns. The abundantly available Abasand samples were subjected to detailed analysis. These samples represent the lower portion of the McMurray formation, lying a few feet above the Devonian limestone. The bitumen was found to be a complex mixture of hydrocarbon and non-hydrocarbon compounds; the character of a few of which can be indicated. The bitumen was observed to be susceptible to contaminations by microorganisms; this required precautions during analysis. The chemical composition of the samples indicates that the Athabasca bitumen is basically a crude oil. End_of_Article - Last_Page 1254------------
Spatial and temporal organization of signaling pathways

The development and maintenance of the many different cell types in metazoan organisms requires robust and diverse intercellular communication mechanisms. Relatively few such signaling pathways have been identified, leading to the question of how such a broad diversity of output is generated from relatively simple signals. Recent studies have revealed complex mechanisms integrating temporal and spatial information to generate diversity in signaling pathway output. We review some general principles of signaling pathways, focusing on transcriptional outputs in Drosophila. We consider the role of spatial and temporal aspects of different transduction pathways and then discuss how recently developed tools and approaches are helping to dissect the complex mechanisms linking pathway stimulation to output.
Testosterone and brain-derived neurotrophic factor interactions in the avian song control system

Interaction between steroid sex hormones and brain-derived neurotrophic factor (BDNF) is a common feature of vertebrate brain organization. The avian song control system provides an excellent model for studying such interactions in neural circuits that regulate song, a learned sensorimotor behavior that is often sexually dimorphic and restricted to reproductive contexts. Testosterone (T) and its steroid metabolites interact with BDNF during development of the song system and in adult plasticity, including the addition of newborn neurons to the pallial nucleus HVC and seasonal changes in structure and function of these circuits. T and BDNF interact locally within HVC to influence cell proliferation and survival. This interaction may also occur transsynpatically; T increases the synthesis of BDNF in HVC, and BDNF protein is then released on to postsynaptic cells in the robust nucleus of the arcopallium (RA) where it has trophic effects. The interaction between sex steroids and BDNF is an example of molecular exploitation, with the evolutionarily ancient steroid-receptor complex having been captured by the more recently evolved BDNF. The functional linkage of sex steroids to BDNF may be of adaptive value in regulating the trophic effects of the neurotrophin in sexually dimorphic and reproductively relevant contexts.
Afterglow studies in helium

Abstract Simultaneous measurements of the time dependence of the intensities of spectral lines and bands and of the number density of atomic and molecular helium ions in a decaying plasma are reported, and a preliminary interpretation is given.
Negative regulation of the SH2-homology–containing protein-tyrosine phosphatase-1 (SHP-1) P2 promoter by the HTLV-1 Tax oncoprotein

Expression of SH(2)-homology-containing protein-tyrosine phosphatase-1 (SHP-1), a candidate tumor suppressor, is repressed in human T-cell leukemia virus type-1 (HTLV-1)-transformed lymphocyte cell lines, adult T-cell leukemia (ATL) cells, and in other hematologic malignancies. However, the mechanisms underlying regulation and repression of SHP-1 remain unclear. Herein, we cloned the putative full-length, hematopoietic cell-specific SHP-1 P2 promoter and identified the "core" promoter regions. HTLV-1 Tax profoundly represses P2 promoter activity and histone deacetylase-1 (HDAC1) potentiates such inhibition. NF-kappaB was implicated as both a rate-limiting factor for basal P2 promoter activity and important for Tax-induced promoter silencing (TIPS). Chromatin immunoprecipitation studies demonstrated that NF-kappaB dissociates from the SHP-1 P2 promoter following the binding of Tax and HDAC1. This is in agreement with coimmunoprecipitation studies where NF-kappaB competed with HDAC1 for association with Tax protein. We propose that in TIPS, Tax recruits HDAC1 to the SHP-1 P2 promoter and forms an inhibitory complex that results in deacetylation and dissociation of NF-kappaB from the promoter and attenuation of SHP-1 expression. TIPS provides a possible first step toward HTLV-1 leukemogenesis through its down-modulation of this key immediate early negative regulator of IL-2 signaling.
Hg stable isotope analysis by the double-spike method

Recent publications suggest great potential for analysis of Hg stable isotope abundances to elucidate sources and/or chemical processes that control the environmental impact of mercury. We have developed a new MC-ICP-MS method for analysis of mercury isotope ratios using the double-spike approach, in which a solution containing enriched 196Hg and 204Hg is mixed with samples and provides a means to correct for instrumental mass bias and most isotopic fractionation that may occur during sample preparation and introduction into the instrument. Large amounts of isotopic fractionation induced by sample preparation and introduction into the instrument (e.g., by batch reactors) are corrected for. This may greatly enhance various Hg pre-concentration methods by correcting for minor fractionation that may occur during preparation and removing the need to demonstrate 100% recovery. Current precision, when ratios are normalized to the daily average, is 0.06‰, 0.06‰, 0.05‰, and 0.05‰ (2σ) for 202Hg/198Hg, 201Hg/198Hg, 200Hg/198Hg, and 199Hg/198Hg, respectively. This is slightly better than previously published methods. Additionally, this precision was attained despite the presence of large amounts of other Hg isotopes (e.g., 5.0% atom percent 198Hg) in the spike solution; substantially better precision could be achieved if purer 196Hg were used.
A Non-Supervised Training Program for Carkhuff's Discrimination and Communication Skills and Its Effects Upon the Reactions of Others during Brief Interactions.

Used Carkhuff's Indices of Communication and Discrimination along with other measures to assess the level of communication and discrimination skills at various stages of communication training. Ss were 14 male and 9 female students in a psychology of adjustment class. Results indicated that: (a) treatment and control groups did not differ in communication skills before they went through training; (b) the treatment group offered higher levels of communication skill after it had completed training than did the control group before it began training; (c) the control group offered levels of communication skill equal to those of the treatment group once the control group also had completed training. A similar pattern was found for discrimination skill. The effects of training cannot be dismissed as paper-and-pencil artifacts because others who were ignorant of the growth conditions concept reacted differently in brief unstructured interactions to those who had completed training.
Prediction of process parameters for intelligent control of tunnel freezers using simulation.

Abstract Various analytical and empirical methods assuming the existence of steady state and requiring homogenous properties of the product have been used with limited success in estimating freezing times in the food processing industry. Irrespective of the method adopted for estimating freezing time requirements, a critical process issue that needs to be considered is that of system control. Simulation models suggest that a feed-forward control strategy, as discussed in this paper, can be used to control a freezing tunnel and obtain considerable energy savings while ensuring `appropriate' freezing of all products. The control strategy discussed in this paper, involves the continuous monitoring of product input and controlling either or both of the refrigerant flow and conveyor speed. The primary objective of this paper is to demonstrate the use of simulation to predict process parameters for `intelligent control' of freezing tunnels, and provide an estimate of potential energy savings.
Diurnal to Annual Precipitation Sensitivity to Convective and Land Surface Schemes

Precipitation's diurnal to annual variance distribution and at- mospheric water cycle component interactions are examined globally for sen- sitivity to convective and land surface schemes. The main regional features of statistics identified in previous reanalyses are robust in unconstrained continu- ous simulations corresponding to the reanalyses' convective and land surface schemes. A change from the simplified Arakawa-Schubert (SAS) to the re- laxed Arakawa-Schubert (RAS) convection scheme reorganizes the varianc eo f rainfall at low latitudes to a redder spectrum. Despite the potential increase in soil moisture memory, a change from the Oregon State University (OSU2) to the Noah land surface model does not noticeably affect the variance distribu- tion of precipitation. The competition between dynamic and thermodynamic