cssi/SciSciGPT-SciSciNet huggingface dataset:
Intrablock Variance among Duplicate Treatments for Nearest-Neighbor Analyses

Nearest-neighbor analysis (NNA) adjusts for spatially correlated residuals, with the goal of increasing precision. The magnitude of the block x treatment interaction mean square is commonly used to evaluate the predsion of the NNA model. An alternative method of evaluating the precision of the NNA and classical unadjusted (UNADJ) randomized complete block (RCB) analysis would be to use the pooled variance between duplicate treatments within each block. We defined pure error as variation between plots that are treated alike within a block. Within each location, each genotype was randomly assigned to two plots within each block of an RCB design. The pure error of soybean [Glycine max (L.) Merr.] genotypes was evaluated at eight locations. Our objective was to compare the block x treatment and pure error mean squares for yield, physiological maturity, and plant height to determine whether the NNA or UNADJ analysis reduces intrablock variation. The NNA analysis always decreased the magnitude of the block x treatment interaction mean squares, compared with the UNADJ analysis. In some comparisons, the pure error mean square of the NNA analysis was significantly smaller than the pure error of the UNADJ analysis. The magnitude of the block x treatment mean square is not useful for comparing the relative precision of these two analyses. When the pure error mean square was used to measure precision, the NNA was at least as precise as the UNADJ analysis.
One-Step Synthesis of Hyperbranched Polyesters. Molecular Weight Control and Chain End Functionalization

A new procedure is described for the preparation of chloride ion free 3,5-bis(trimethylsiloxy)benzoyl chloride, which allows the reproducible preparation of hyper-branched aromatic polyesters with controllable molecular weights. The pure monomer is thermally stable at temperatures of more than 200°C, but is readily polymerized when heated in the presence of catalytic amounts of dimethylformamide or trimethylamine hydrochloride. The molecular weight of the polymers increases with higher reaction temperatures, longer reaction times, and larger amounts of catalyst. Polymerizations in o-dichlorobenzene also afford similar results. The hyperbranched polyesters have degrees of branching of ca. 60% and contain a large number of free phenolic groups both at the chain-ends and in “linear” portions of the chains. Functionalization of these free phenolic hydroxyls is readily accomplished in homogeneous solution. However, reactions with solid Pd/C catalyst were not possible. The solubility and thermal properties of the resulting blocked hyperbranched aromatic polyesters reflect the choice of hydroxyl protecting group.
Systemic is Governance: An Introduction

Abstract Governance processes are a legal necessity; but beyond that, they're fundamental to the success of every organization. When governance processes are well designed, they coordinate every aspect of an organization: its people, equipment, and money work in concert toward the strategic objectives of the firm. However, when poorly designed, governance processes can be counterproductive. This article presents a fresh perspective on IS governance as five interdependent organizational systems. the objective is to help leaders understand the scope of the IS governance challenge, and to provide an introduction to design processes that coordinate and control the IS organization while enhancing, not stifling, everyone's performance.
Asymptotic stability and boundedness of non-linear difference equations†

The problem of asymptotic stability and boundedness of non-linear difference equations is considered, In this paper we shall show some results which guarantee asymptotic stability for the trivial solution. Wo wish to present results which provide explicit regions of asymptotic stability. The results replace these words, 1 sufficiently small', by explicit estimates which are simple. The concept of asymptotic stability to difference equations can be quite useful in the design of system response to arbitrary initial conditions.
Flowability and density characteristics of controlled low-strength material using native high-plasticity clay

AbstractIn pipeline construction projects when high-plasticity clayey soils are encountered in the excavated trench material, they are typically landfilled and better quality materials are imported from outside quarry sources for use as bedding and haunch-zone materials. This practice has detrimental environmental and cost impacts; therefore, an efficient reutilization of this high-plasticity excavated material to produce controlled low-strength materials (CLSMs) to use as bedding and haunch-zone materials will have major sustainability benefits. As part of an ongoing research study, novel CLSM mix designs were developed by utilizing native high-plasticity clayey soils from the excavated trench material. Due to the high-plasticity nature of the soils, it is essential to address both flowability and density property requirements prior to validating them against other engineering properties. Hence, several CLSM mixtures with the native clayey soils as ingredients were initially designed as per a flowability...
Stem cells: The promises and perils of p53.

Five studies show that disabling p53, an essential tumour-suppressor protein, improves the efficiency of stem-cell production. Are these results a ‘heads up’ that cancer cells and stem cells are disturbingly similar?
Lifetime assessment of atomic-layer-deposited Al2O3–Parylene C bilayer coating for neural interfaces using accelerated age testing and electrochemical characterization

Abstract The lifetime and stability of insulation are critical features for the reliable operation of an implantable neural interface device. A critical factor for an implanted insulation’s performance is its barrier properties that limit access of biological fluids to the underlying device or metal electrode. Parylene C is a material that has been used in FDA-approved implantable devices. Considered a biocompatible polymer with barrier properties, it has been used as a substrate, insulation or an encapsulation for neural implant technology. Recently, it has been suggested that a bilayer coating of Parylene C on top of atomic-layer-deposited Al 2 O 3 would provide enhanced barrier properties. Here we report a comprehensive study to examine the mean time to failure of Parylene C and Al 2 O 3 –Parylene C coated devices using accelerated lifetime testing. Samples were tested at 60 °C for up to 3 months while performing electrochemical measurements to characterize the integrity of the insulation. The mean time to failure for Al 2 O 3 –Parylene C was 4.6 times longer than Parylene C coated samples. In addition, based on modeling of the data using electrical circuit equivalents, we show here that there are two main modes of failure. Our results suggest that failure of the insulating layer is due to pore formation or blistering as well as thinning of the coating over time. The enhanced barrier properties of the bilayer Al 2 O 3 –Parylene C over Parylene C makes it a promising candidate as an encapsulating neural interface.
Subacute cutaneous lupus erythematosus-immunogenetic associations

Thirty-two patients who fulfilled criteria for subacute cutaneous lupus erythematosus (SCLE) were examined for their immunogenetic associations. Our results confirm the previously reported association of HLA-DR3 (15/31 48% P less than 0.01) and also demonstrate an increase in HLA-DR2 (14/31, 45%, P = less than 0.05). These findings indicate there are two distinct immunogenetic (HLA) populations of Ro(SS-A) antibody-positive SCLE patients. The increased frequency of HLA-DR2 and DR3 appears to be associated with expression of the Ro(SS-A) antibody, since no HLA associations were seen in Ro(SS-A)-negative SCLE patients when compared with normal population controls. Furthermore, these data indicate that the distinctive cutaneous lesions of SCLE are not associated with one specific HLA allele, as previously suspected. These findings contrast with the relatively homogeneous immunogenetic background seen in other lupus erythematosus subsets with a high frequency of Ro(SS-A) antibody, i.e., neonatal lupus erythematosus and Sjogren's syndrome/lupus erythematosus overlap (increased frequency of HLA-DR3, DQw2 and DRW52).
Nonnegative matrices A with AA♯⩾0

In this paper we obtain a decomposition of nonnegative matrices A such that AA# ≥ 0. We then use this characterization to obtain the previous results known for nonnegative matrices A with A 3 ≥ 0. We also consider nonnegative matrices A with A - A 2 ≥ 0.
Meeting Report: Joint NSLS and CFN 2006 Users' Meeting

Arosy future was forecast for Brookhaven National Laboratory's (BNL) user facilities at the first-ever joint meeting of the user communities for the National Synchrotron Light Source (NSLS) and the Center for Functional Nanomaterials (CFN), held May 15–17, 2006.
Defining a Molecular Mechanism of Synergy between Nucleoside and Nonnucleoside AIDS Drugs

Combination therapies treating human immunodeficiency virus type 1 (HIV-1) infection delay the emergence of drug-resistant virus and exhibit synergistic inhibition. This synergy is observed within the two classes of inhibitors that target the essential viral reverse transcriptase (RT): the chain-terminating nucleoside analogs (NRTIs) and the allosteric nonnucleosides (NNRTIs) that bind in a pocket distinct from the active site. A general mechanism to define the molecular basis for synergy between these two classes remains to be elucidated. Previous mechanistic studies from our laboratory (Spence, R. A., Kati, W. M., Anderson, K. S., and Johnson, K. A. (1995) Science 267, 988-993) have shown that the natural deoxynucleoside triphosphate and the NNRTI can simultaneously bind to their respective sites. This work also suggests communication between the two sites, since the inhibition of RT by NNRTIs is manifested through a remote effect on the chemical step. This interplay between the two sites offers a plausible hypothesis for understanding synergy in which binding of NNRTIs modulates the chain termination by NRTIs. The present study supports this hypothesis by illustrating that the clinically approved NNRTIs, nevirapine and efavirenz, inhibit the ATP-mediated removal of AZTMP, d4TMP, ddCMP, (-)3TCMP, (-)FTCMP, and (+)3TCMP, thereby prolonging the effectiveness of chain termination. This inhibition is mediated through an effect on both the rate of the chemical step and binding of ATP, resulting in an overall decrease in efficiency of removal. This work substantiates communication between the two binding pockets, the sustained use of combination therapy to treat HIV infection, and a molecular basis for understanding synergy.
Designing a new 330-kv outdoor air switch

THE USE of 330 kv as a system voltage involves many problems, and the experimental equipment and line installation by the American Gas and Electric Service Corporation at their Tidd Plant resulted in new ideas and data for solutions to corona, insulation, line loss, protection, and other problems.
Effects of central vasotocin and mesotocin manipulations on social behavior in male and female zebra finches

Male and female zebra finches (Taeniopygia guttata; total n = 40) were fitted with chronic guide cannulae directed at the lateral ventricle and were tested for aggression, affiliation, and partner preference following infusions of mesotocin (MT), vasotocin (VT), their antagonists, and vehicle control. Aggressive behavior was tested in a mate competition paradigm and tests of intersexual affiliation and partner preference were conducted following 1 day of cohabitation with an opposite-sex individual. These tests also provided data on male courtship singing. The results demonstrate a modest dose-dependent facilitation of aggression by VT, but not MT, in both male and female finches. However, only males were sensitive to infusions of a vasopressin antagonist, suggesting that endogenous VT is more important for behavioral modulation in males. Peptide effects were specific to aggression, as no treatments influenced intersexual affiliation, partner preference, or male courtship singing. Thus, in contrast to rodents, partner preference is not readily induced by VT or MT in this species. However, the potential necessity of endogenous VT and MT for natural pair-bond formation remains to be tested.
Composite Hollow Fiber Membranes for Gas Separation: The Resistance Model Approach

Of the potential limitations to the use of membranes for gas separation, one of the most difficult to overcome has been that of inadequate permeation rate. Indeed, this limitation applies not only to gas separations, but to all separations for which membranes have been used.
Binge pattern ethanol exposure in adolescent and adult rats: differential impact on subsequent responsiveness to ethanol.

Background: Recent evidence indicates that adolescent animals are more sensitive than adults to the disruptive effects of acute ethanol exposure on spatial learning. It is not yet known whether adolescent animals are also more sensitive than adults to the enduring neurobehavioral effects of repeated ethanol exposure. In this study, animals were exposed to ethanol in a binge-pattern during either adolescence or adulthood. At a time when all subjects were adults, spatial working memory was examined in the absence and presence of an acute ethanol challenge. Methods: Rats were exposed to ethanol (5.0 g/kg intraperitoneally) or isovolumetric saline at 48 hr intervals over 20 days. Exposure began on either postnatal day 30 (adolescent group) or 70 (adult group). Twenty days after the final injection, a time at which all animals were adults, the subjects were tested on an elevated plus maze and then were trained to perform a spatial working memory task on an eight-arm radial maze. At the beginning of each session of training on the working memory task, subjects retrieved food rewards on four of the eight arms. After a delay, subjects were placed on the maze and allowed to retrieve food from the remaining four arms. Results: Prior exposure to ethanol did not influence behavior on the plus maze. Performance of the groups did not differ during acquisition of the spatial working memory task with a 5 min delay or during subsequent testing with a 1 hr delay. However, animals treated with ethanol during adolescence exhibited larger working memory impairments during an ethanol challenge (1.5 g/kg intraperitoneally) than subjects in the other three groups. Conclusions: The findings indicate that binge pattern exposure to ethanol during adolescence enhances responsiveness to the memory-impairing effects of ethanol in adulthood.
Reliability and validity of the Duruoz Hand Index in persons with systemic sclerosis (scleroderma).

Objective To examine the test–retest reliability and concurrent validity of the Duruoz Hand Index (DHI) in persons with scleroderma. Methods Forty patients with scleroderma and no other major medical problems completed the DHI at 2 points in time to assess test–retest reliability. To assess validity, participants were administered the Arthritis Hand Function Test (AHFT), the Hand Mobility in Scleroderma Test (HAMIS), and the Keital Function Test (KFT), all performance-based tests. In addition, participants completed the Health Assessment Questionnaire (HAQ), a self report of functional ability. Results Test–retest reliability intraclass correlation coefficients for the DHI ranged from 0.81 to 0.97. Scores on the DHI did not correlate with HAMIS scores, but were significantly correlated with scores from the KFT (rs = 0.48, P < 0.01), HAQ (rs = 0.79, P < 0.01), and all sections of the AHFT (rs = 0.34–0.60, P < 0.05–0.01). Conclusion The results from this study show the DHI to be a reliable and valid test for persons with scleroderma.
Polycyclic aromatic hydrocarbons in surface sediments held in experimental mesocosms

Sediment was collected from three locations along a pollution gradient in Narragansett Bay and transplanted to controlled mesocosms. Total hydrocarbons and eleven individual polycyclic aromatic hydrocarbons (PAHs) were measured in these sediments over a period of 394 days. Total hydrocarbon concentrations increased in the “relatively uncontaminated”; (Rhode Island Sound) sediment that was held in the mesocosms, but did not change in the two other sediments. The concentrations of four PAHs: naphthalene, 2‐methyl naphthalene, 1‐methyl naphthalene and biphenyl, decreased in the “contaminated”; (Providence River) sediment during the experiment and the calculated half‐lives for these compounds were 287, 353, 321 and 333 days, respectively.
Improving the United States' System of Care for Older Adults With Mental Illness: Findings and Recommendations for The President's New Freedom Commission on Mental Health

The President's New Freedom Commission on Mental Health was created to evaluate the quality and effectiveness of the nation's mental health service delivery system, to identify unmet needs and barriers to services, and to provide recommendations on methods for improving the mental health system. A health policy analysis was prepared for the Commission examining the organization, delivery, and financing of mental health services for older Americans. The author identified three healthcare themes, including 1) access and continuity of services; 2) quality; and 3) workforce and caregiver capacity. From among these areas, 10 policy issues and recommendations were proposed.
Differential Behavior of Two Photosystem II Inhibitors in Seashore Paspalum

Seashore paspalum (Paspalum vaginatum Sw.) injury from triazines has limited the mechanisms of action used for postemergence (POST) weed control. Seashore paspalum is tolerant to a new Photosystem (PS) II inhibitor, amicarbazone (4-amino-N-tert-butyl-4,5-dihydro-3-isopropyl-5-oxo-1H-1,2,4-triazole-1-carboxamide), but the physiological behavior attributed to differential tolerances from triazines has received limited investigation. The objectives of this research were to evaluate efficacy, absorption, translocation, and metabolism of ¹⁴C-amicarbazone and ¹⁴C-atrazine (1-chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine) in cultivar Sea Isle 1 seashore paspalum. In greenhouse experiments, atrazine treatments (560, 1120 or 2240 g a.i. ha–¹) reduced shoot mass from the nontreated two times greater than amicarbazone treatments (98, 196, or 392 g a.i. ha–¹). In laboratory experiments, foliar absorption of ¹⁴C-amicarbazone increased from 1 to 7 days after treatment (DAT) but peak absorption of ¹⁴C-atrazine occurred after 1 d. The ¹⁴C translocation from both herbicides was similar following root and shoot absorption. Seashore paspalum metabolized approximately two times more amicarbazone than atrazine after 1 d in foliar and root absorption experiments. From root absorption, seashore paspalum produced three metabolites of amicarbazone in roots and shoots at 1 and 3 DAT but only one metabolite of atrazine was found after 1 d. Three metabolites of atrazine were recovered at 3 DAT in shoots but only one metabolite was found in roots. Overall, faster metabolism in roots and shoots contributes to the greater tolerance of seashore paspalum to amicarbazone compared to atrazine.
Measuring the cost of plasticity: avoid multi-collinearity.

There are many different ways to measure phenotypic plasticity [[1][1]]. In the endeavour to measure the costs of plasticity, researchers often employ large quantitative-genetic experimental designs that rear related groups of organisms in two environments. Under such two-environment designs,
Time-domain power system simulator as an efficient tool for teaching and learning electric power quality phenomena

Electric power quality (PQ) phenomena involve the interaction between various elements of the power system. Due to the complex nature of the phenomena, electric PQ education at the undergraduate level is challenging. The instructional method is typically based on the traditional descriptive-inquiry approach. This article suggests that a time-domain computer-based simulation tool be used to supplement the traditional approach. The combined method allows students to simulate complex phenomena in a controlled environment so as to investigate the interaction between power system elements that give rise to the phenomena, and how the phenomena impact the system. The combined method is expected to reinforce and enhance the student learning process. The article then presents three simulation examples to demonstrate how the time-domain simulation method can be integrated into the traditional descriptive-inquiry method. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 17: 214–224, 2009; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae20194
Tyrosine Hydroxylase mRNA Expression by Dopaminergic Neurons in Culture: Effect of 1 -Methyl-4-Phenylpyridinium Treatment

To enable us to study expression of tyrosine hydroxylase [TH; tyrosine 3-monooxygenase; L-tyrosine tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating); EC 1.14.16.2] as a measure of dopaminergic neuron function in future experiments, methods were developed to quantify TH mRNA levels in cultures of dopaminergic mesencephalic cells. The model of selective dopaminergic toxicity of 1-methyl-4-phenylpyridinium (MPP+) was used to verify the specificity of our methods. Fetal (embryonic day 15) rat ventral mesencephalic cell cultures were treated with 15 microM MPP+ for 48 h, conditions previously shown to reduce the number of TH-immunoreactive neurons, TH activity, and dopamine uptake to 5-10% of control values. This treatment decreased the number of neurons labeled by TH in situ hybridization to 9% of untreated controls and caused a strong reduction of the abundance of TH mRNA in Northern blots. Our findings establish TH mRNA expression as a parameter for future studies of toxic and trophic effects on cultured dopaminergic neurons, and they support the view that MPP+ destroys dopaminergic neurons.
Migrant Remittances and Skipped Generation Households: Investigating the Exchange Motive Using Evidence from Nang Rong, Thailand:

Using data from the Nang Rong projects social survey (N=6,801 households) and qualitative data from semi-structured interviews, I examine the relationship between migrant remittances and the skipped generation household structure. I find that the skipped generation household is a significant determinant of in-kind remittances and the amount of remittances received by the household. Surprisingly, although qualitative data suggest that grandparents living in skipped generation households provide childcare for the children of absent migrants, quantitative evidence reveals that these households receive lower remittance amounts than other households. This suggests that although an exchange motivation may be overlooked in the remittance literature, it does not apply to migrant remittances as it does in the broader literature on inter vivos intergenerational transfers.
Dynamic microwaviness measurements of super smooth disk media used in magnetic hard disk drives

Abstract Recent technological advances in magnetic storage suggest the feasibility of extremely high-density magnetic recording up to 1 terabit per square inch (1 Tbit=1012 bits) areal densities. Modelling indicates that approximately 3 nanometers (nm) of physical head-disk spacing is required for such high recording densities. When the recording slider is flying at such ultra low spacing over a high-speed rotating disk, it is experiencing disturbances from various different sources and of a wide frequency range. These disturbances may cause the recording slider to vibrate significantly, a condition that is known as fly height modulation (FHM), which may result in data loss. A significant source of excitation is from the surface irregularities of the rotating disk and is termed dynamic microwaviness. The term dynamic microwaviness has been introduced recently to differentiate from regular topographical features that are measured statically. In this paper, the procedure for making reliable dynamic microwaviness measurements of disk media used in hard disk drive (HDD) systems is described. Furthermore, such measurements are performed on different super smooth magnetic disks that are intended for extremely high recording densities using non-contact laser vibrometry. The root-cause of the dynamic microwaviness is investigated by measuring disk topographical features under static conditions and the interaction with system dynamics. It is found that dynamic microwaviness is primarily due to topographical features of spatial wavelengths ranging from 58.8 to 250 μm, and secondarily due to system dynamic effects.
6Li and Gamma Rays: Complementary Constraints on Cosmic-Ray History

The rare isotope 6Li is made only by cosmic rays, predominantly in αα → 6Li fusion reactions with interstellar medium (ISM) helium. Consequently, this nuclide provides a unique diagnostic of the history of cosmic rays in our Galaxy. The same hadronic cosmic-ray interactions also produce high-energy γ-rays (mostly via pp → π0 → γγ). Thus, hadronic γ-rays and 6Li are intimately linked. Specifically, 6Li directly encodes the local cosmic-ray fluence over cosmic time, while extragalactic hadronic γ-rays encode an average cosmic-ray fluence over lines of sight out to the horizon. We examine this link and show how 6Li and γ-rays can be used together to place important model-independent limits on the cosmic-ray history of our Galaxy and the universe. We first constrain γ-ray production from ordinary Galactic cosmic rays, using the local 6Li abundance. We find that the solar 6Li abundance demands an accompanying extragalactic pionic γ-ray intensity that exceeds that of the entire observed extragalactic γ-ray background (EGRB) by a factor of 2-6. Possible explanations for this discrepancy are discussed. We then constrain Li production using recent determinations of the EGRB. We note that cosmic rays created during cosmic structure formation would lead to pre-Galactic Li production, which would act as a "contaminant" to the primordial 7Li content of metal-poor halo stars; the EGRB can place an upper limit on this contamination if we attribute the entire EGRB pionic contribution to structure-forming cosmic rays. Unfortunately, the uncertainties in the determination of the EGRB are so large that the present γ-ray data cannot guarantee that the pre-Galactic Li contribution is small compared to primordial 7Li; thus, an improved determination of the EGRB will shed important new light on this issue. Our limits and their more model-dependent extensions will improve significantly with additional observations of 6Li in halo stars and with improved measurements of the EGRB spectrum by GLAST.
104 Super Critical Nitrogen: Assessing the performance and thermal characteristics of a novel cryosurgical device

Today’s cryosurgical devices can be characterized by the type of cryogen employed. The most common, and current industry standard, utilizes a gas undergoing Joule-Thomson (JT) cooling. These gaseous cryogen devices can use small diameter probes that generate freezing temperatures near instantaneous, but due to the sub-optimal heat extraction of gases, often require large numbers of probes and/or extended applications. In contrast, liquid cryogen devices offer superior heat extraction, but with larger and slower acting probes. We recently developed a novel platform utilizing super critical nitrogen (SCN) as the cryogen, and have set out to quantify the performance of the system and compare it to that of an argon JT device. In this study, the isotherms generated during a freeze procedure were assessed with thermocouple arrays in various tissue approximations: water, ultrasound gel, and porcine muscle sections. It was found that the SCN system created significantly colder nadir temperatures (−170 °C as compared to −140 °C) and did so in approximately half the time. Additionally, the SCN system generated −40 °C and −20 °C isotherm volumes that were 300% and 32% larger than those of a JT device. Finally, comparing the surface freezing of porcine muscle sections (5–10 mm thickness), it was found that the SCN platform created full thickness lesions that were colder and more defined than JT devices while requiring less than half the freeze duration. The use of the SCN platform combines the miniaturization and speed of a JT device with the ultra cold nadir temperatures and cooling potential of a liquid nitrogen system and may represent the next generation of cryosurgical devices. Source of funding: CPSI Biotech. Conflict of interest: None declared. arobilotto@cpsibiotech.com
Youths in Violent Extremist Discourse: Mediated Identifications and Interventions

This article examines the discursive strategies employed by violent extremists to build a persuasive collective youth identity, drawing from strategic communication, social movement, and membership categorization theories to analyze youth references from texts disseminated by Al Qaeda from 1996–2009. “Youth” is constructed via (a) ascriptions of allegiance to a common belief system whereby militant actions are directed toward establishing a new sociopolitical order, (b) descriptions of pious youth as “true believers” apart from “apostate” state regimes, and (c) references to hagiographies of extremist martyrs that serve as moral exemplars. This article concludes with research directions to facilitate counternarrative interventions.
The effect of instruction set complexity on program size and memory performance

One potential disadvantage of a machine with a reduced instruction set is that object programs may be substantially larger than those for a machine with a richer, more complex instruction set. The main reason is that a small instruction set will require more instructions to implement the same function. In addition, the tendency of RISC machines to use fixed length instructions with a few instruction formats also increases object program size. It has been conjectured that the resulting larger programs could adversely affect memory performance and bus traffic. In this paper we report the results of a set of experiments to isolate and determine the effect of instruction set complexity on cache memory performance and bus traffic. Three high-level language compilers were constructed for machines with instruction sets of varying degrees of complexity. Using a set of benchmark programs, we evaluated the effect of instruction set complexity had on program size. Five of the programs were used to perform a set of trace-driven simulations to study each machine's cache and bus performance. While we found that the miss ratio is affected by object program size, it appears that this can be corrected by simplying increasing the size of the cache. Our measurements of bus traffic, however, show that even with large caches, machines with simple instruction sets can expect substantially more main memory reads than machines with dense object programs.
Influence of pH and rapidly fermentable carbohydrate on mineral release in and flow from the rumen.

Objectives for this study were to determine the effect of energy supplementation on mineral release in and outflow from the rumen, independent of pH. Nonlactating Holstein cattle with ruminal cannulas were limit-fed chopped alfalfa hay with or without energy supplement. Treatments were 1) control, alfalfa plus ruminal infusion of 3 L/d of distilled water; 2) acid, alfalfa plus infusion of 3 L/d of 1N HCl; 3) energy supplement, alfalfa and ground corn plus infusion of 3 L/d of distilled water; and 4) buffered energy supplement, alfalfa, and ground corn plus infusion of 3 L/d of distilled water containing 90 g of NaHCO3. Macromineral intake was standardized across treatments by adjustment of infusion solutions with inorganic mineral sources. Dry matter consumed was 5 kg/d on treatments 1 and 2 and 8.4 kg/d on treatments 3 and 4. Mean ruminal pH was 6.8, 6.1, 5.6, and 6.2 for treatments 1 through 4, respectively. Ruminal pH was more significant than energy supplementation in dispersion of Ca, Mg, and P in ruminal digesta. Only 1, 17, and 27% of dietary K, Mg, and P flowed with solids from the rumen, but 52% of Ca and 41% of Cu remained with the solid phase.
Ultrastructural characterization of the optic pathway in a mouse model of neurofibromatosis-1 optic glioma.

The purpose of this study was to investigate the progression of changes in retinal ganglion cells and optic nerve glia in neurofibromatosis-1 (NF1) genetically-engineered mice with optic glioma. Optic glioma tumors were generated in Nf1+/− mice lacking Nf1 expression in GFAP+ cells (astrocytes). Standard immunohistochemistry methods were employed to identify astrocytes (GFAP, S100β), proliferating progenitor cells (sox2, nestin), microglia (Iba1), endothelial cells (CD31) and retinal ganglion cell (RGC) axons (Neurofilament 68k) in Nf1+/−, Nf1GFAPCKO (wild-type mice with Nf1 loss in glial cells), and Nf1+/−GFAPCKO (Nf1+/− mice with Nf1 loss in glial cells) mice. Ultrastructural changes in the optic chiasm and nerve were assessed by electron microscopy (EM). RGC were counted in whole retina preparations using high-resolution, mosaic confocal microscopy following their delineation by retrograde FluoroGold labeling. We found that only Nf1+/−GFAPCKO mice exhibited gross pre-chiasmatic optic nerve and chiasm enlargements containing aggregated GFAP+/nestin+ and S100β+/sox2+ cells (neoplastic glia) as well as increased numbers of blood vessels and microglia. Optic gliomas in Nf1+/−GFAPCKO mice contained axon fiber irregularities and multilamellar bodies of degenerated myelin. EM and EM tomographic analyses showed increased glial disorganization, disoriented axonal projections, profiles of degenerating myelin and structural alterations at nodes of Ranvier. Lastly, we found reduced RGC numbers in Nf1+/−GFAPCKO mice, supporting a model in which the combination of optic nerve Nf1 heterozygosity and glial cell Nf1 loss results in disrupted axonal-glial relationships, subsequently culminating in the degeneration of optic nerve axons and loss of their parent RGC neurons.
Erratum: Relation between elastic tensors of wurtzite and zinc-blende structure materials

A transformation is derived which relates the fourth-rank elastic tensors of the two common modifications of tetrahedrally coordinated compounds, cubic zinc blende (ZB), and hexagonal wurtzite (Wz). The basic assumptions are that the local tetrahedra extending to second neighbors about each atom are rotated but otherwise identical in the two structures, and that differences between ZB and Wz for third and more distant neighbors are negligible. The procedure involves Robinson's rotations which apply to any tensorial property, to which is added internal strain between the two inequivalently oriented tetrahedra in the Wz structure. Good agreement is found with empirical constants of ZnS which have been measured in both structures. The transformation permits a simple derivation of "effective" cubic constants for Wz compounds, which are sufficient to extract the most important information on average tetrahedral forces. Effective constants are compared with measured ZB constants for the entire range of tetrahedrally coordinated compounds.
Amplification and detection of substrates for protein carboxyl methyltransferases in PC12 cells.

A strategy that facilitates the identification of substrates for protein carboxyl methyltransferases that form "stable" methyl esters, i.e., those that remain largely intact during conventional polyacrylamide gel electrophoresis is described. Rat PC12 cells were cultured in the presence of adenosine dialdehyde (a methylation inhibitor) to promote the accumulation of hypomethylated proteins. Nonidet P-40 cell extracts were then incubated in the presence of S-[methyl-3H]adenosyl-L-methionine to label methyl-accepting sites via endogenous methyltransferases. After labeled proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel slices were incubated in 4 N methanesulfonic acid or 6 N HCl to hydrolyze methyl esters. The resulting [3H]methanol was detected by trapping in liquid scintillation fluid. Seven carboxyl methylated proteins were observed with masses ranging from 18 to 96 kDa. Detection of five of these proteins required prior treatment of cells with adenosine dialdehyde, while methyl incorporation into one protein at 18 kDa was substantially enhanced by the treatment. The use of acidic conditions for methyl ester hydrolysis has an important advantage over assays that utilize alkaline hydrolysis conditions. In PC12 cells, and possibly other cell types where there are significant levels of arginine methylation, the methanol signal becomes obscured by high levels of volatile methylamines generated under the alkaline conditions. Carrying out diffusion assays under acidic conditions eliminates this interference. Adenosine dialdehyde, by virtue of increasing the methyl-accepting capacity of substrates for protein carboxyl methyltransferases, in combination with a more selective assay for carboxyl methylation, should prove useful in the isolation and characterization of new protein carboxyl methyltransferases and their substrates.
Spatial variability of hydraulic conductivity in a cultivated field at different times

Farming practices and climatic patterns may alter soil surface hydraulic conductivity (K) both spatially and at different times during a season. This study quantified spatial variability and spatial dependence of ponded and tension K measurements in a cultivated field at different times. Paired small-base infiltrometers (76-mm diameter) were used at four pressure heads (5, - 30, - 60, and -150 mm) to measure K across a transect four times during one and a half growing seasons (1-2 July 1991, 12-13 Aug. 1991, 29-30 Apr. 1992, and 28-29 May 1992). A natural log transformation best normalized ponded K data, but In(K + 1) was better for the tension data. Periodicity was apparent for K at a head (h) of - 150 mm, with a significant period of 46 m for July 1991, 147 m for April 1992, and 96 m for May 1992. The periods for the three dates may be three different harmonics. The July periodicity was consistent with expected wheel traffic patterns from the previous harvest; K measurements would have coincided with wheel tracks every 46 m for the July 1991 measurement date. Periodicity for other dates had no apparent cause. For ponded K, only within-pair data were spatially correlated (0.6-0.8 m). At a head of -150 mm, K values were spatially correlated over distances of 6.6, 16.8, and 0.6 m for the measurements of July 1991, April 1992, and May 1992, respectively. Correlation distances were intermediate for K -30 and K -60 . Since spatial correlation and periodicity varied with measurement date, one set of transect measurements was not adequate to describe spatial variability of K.
Reply to Gallant and Kleinman on Symbolic Interactionism vs. Ethnomethodology

There have been several rounds of debate over the last ten years concerning the relationship between ethnomethodology and established social theory, during the course of which ethnomethodology has consistently been short-changed. Ethnomethodology has at one time been accused of being relativistic, and then at another of being positivistic; it has been accused of positing no social structure at all, and on the other hand of positing an invariant one. In fact, ethnomethodology, like Marxism in the 1950’s, has been accused of most things. Even if ethnomethodology were guilty of some of the things it has been accused of over the years, it could not be guilty of all of them because the critics, in fact, contradict themselves. Yet, time and again, these same criticisms are relied upon in launching fresh attacks.’ Since the critics are themselves innacurate it should not be surprising that those trying to follow the debate find ethnomethodology confusing. Hopefully a clear reading might set things right. It is my profound hope that the important theoretical issues which have been raised by ethnomethodology may be recognized and take their proper place in the discipline of sociology. While purporting to distinguish between Symbolic Interaction and Ethnomethodology, the recent paper “Symbolic Interactionism vs. Ethnomethodology” , by Gallant and Kleinman, reproduces most of the usual misunderstandings of ethnomethodology , and even adds one or two new points of confusion. I will address the following points:
Modeling Linear Free Radical Copolymerization by Digital Encoding

Copolymer chains are characterized by chain length, chain composition, and sequence length distributions. Despite the wealth of information these distributions provide, they are incapable of determining the microstructure and concentration of individual chain types along the conversion path at the level of “polymeric isomers”, which are chains of same length and composition but have different monomeric sequences. This work is intended to develop the mathematical equations of “digital encoding of polymer chains”, which is a technique that encapsulates all the information about polymer chain architecture in a unique descriptive manner and is capable of determining the concentrations of all polymer chain types and their isomers. Two types of histograms can be generated: the encoded sequence length distribution (SLD) and the chain type distribution (CTD), which enable a specific visualization of results.
Evaluation of tissue disposition, myelopoietic, and immunologic responses in mice after long-term exposure to nickel sulfate in the drinking water.

Female B6C3F1 mice were exposed to graded doses of nickel sulfate to determine a threshold response for myelotoxicity and immunotoxicity, and to identify which of the populations of lymphoreticular cells were most sensitive to the toxic effects of nickel. Animals were given free access to the chemical in the drinking water at 0, 1, 5, or 10 g/l for 180 d. Water consumption, blood and tissue nickel concentrations, body and organ weights, histopathology, immune responses, bone marrow cellularity and proliferation, and cellular enzyme activities were evaluated. There was no mortality. Mice in the 5‐g/l and 10‐g/l dose groups drank less water than controls; the responses measured in the 10‐g/l group may have been due to a combination of dehydration and chemical toxicity. Decreases in body and organ weights were confined to mice in the 10‐g/l dose group, except for the dose‐related reductions in thymus weights. Blood nickel was measured at 4, 8, 16, and 23 wk of exposure. The mean blood nickel values showed in...
Developing operational performance metrics using image comparison metrics and the concept of degradation space

. A technique for determining relative degradations from image metrics is presented along with a technique for predicting sensor performance from metrics. These techniques are illustrated with degradations of blur and noise in thermal imagery. These uses of metrics are depicted as mappings among a degradation space, an image quality metric space, and an operational performance space. This technique has utility in sampled imagery applications where input and output image comparison is possible, e.g., validation of an infrared scene projector (IRSP), testing image compression algorithms, image simulation, etc. Such applications have a known input image and a degraded output image. With the input image, one can characterize the output image in terms of its degradations relative to the input. The concept of a degradation space leads to developing an Operational Performance Metric (OPM) in terms of more traditional Image Quality Metrics (IQMs). The technique is illustrated using empirical results for human observers performing recognition tasks with thermal imagery in a degradation space of blur and noise.
A human-computer cooperative system for effective high dimensional clustering

High dimensional data has always been a challenge for clustering algorithms because of the inherent sparsity of the points. Therefore, techniques have recently been proposed to find clusters in hidden subspaces of the data. However, since the behavior of the data may vary considerably in different subspaces, it is often difficult to define the notion of a cluster with the use of simple mathematical formalizations. In fact, the meaningfulness and definition of a cluster is best characterized with the use of human intuition. In this paper, we propose a system which performs high dimensional clustering by effective cooperation between the human and the computer. The complex task of cluster creation is accomplished by a combination of human intuition and the computational support provided by the computer. The result is a system which leverages the best abilities of both the human and the computer in order to create very meaningful sets of clusters in high dimensionality.
Study of the parametric oscillator driven by narrow‐band noise to model the response of a fluid surface to time‐dependent accelerations

A stochastic formulation is introduced to study the large amplitude and high‐frequency components of residual accelerations found in a typical microgravity environment (or g‐jitter). The linear response of a fluid surface to such residual accelerations is discussed in detail. The analysis of the stability of a free fluid surface can be reduced in the underdamped limit to studying the equation of the parametric harmonic oscillator for each of the Fourier components of the surface displacement. A narrow‐band noise is introduced to describe a realistic spectrum of accelerations, that interpolates between white noise and monochromatic noise. Analytic results for the stability of the second moments of the stochastic parametric oscillator are presented in the limits of low‐frequency oscillations, and near the region of subharmonic parametric resonance. Based upon simple physical considerations, an explicit form of the stability boundary valid for arbitrary frequencies is proposed, which interpolates smoothly between the low frequency and the near resonance limits with no adjustable parameter, and extrapolates to higher frequencies. A second‐order numerical algorithm has also been implemented to simulate the parametric stochastic oscillator driven with narrow‐band noise. The simulations are in excellent agreement with our theoretical predictions for a very wide range of noise parameters. The validity of previous approximate theories for the particular case of Ornstein–Uhlenbeck noise is also checked numerically. Finally, the results obtained are applied to typical microgravity conditions to determine the characteristic wavelength for instability of a fluid surface as a function of the intensity of residual acceleration and its spectral width.
Influence of delayed metamorphosis on survival, growth, and reproduction of the marine polychaete Capitella sp. I

Abstract In the absence of an appropriate environmental cue, larvae of benthic marine invertebrates typically delay their metamorphosis. Delaying metamorphosis is considered beneficial in promoting placement of offspring into suitable habitats and likely increasing genetic exchange among populations. However, recent studies suggest that delaying metamorphosis can reduce juvenile fitness in some species, by reducing postmetamorphic survivorship or growth rate. The effects of delayed metamorphosis on survival, growth, and reproduction of the marine polychaete Capitella sp. I were tested. The lecithotropic larvae, which are competent to metamorphose within minutes of their release from the parental brood tube, were forced to delay metamorphosis for up to 216 h at 20°C. We induced metamorphosis at intervals by adding azoic sediment, and then reared the juveniles in the laboratory for up to 4 wk. Although survival was significantly reduced ( P 72h, delaying metamorphosis had no convincing effect on postmetamorphic growth rate (μg tissue· day −1 ), time to first reproductive activity, or fecundity.