cssi/SciSciGPT-SciSciNet huggingface dataset:
Selecting perforation intervals and stimulation technique in the Khuff reservoir for improved and economic gas recovery

Abstract Saudi Aramco has initiated an acid fracturing program to treat the carbonates of the Khuff reservoir in the Ghawar field in the eastern province of Saudi Arabia. Khuff reservoir belongs to the Permian age and is encountered at an average depth of about 11,500 ft. Two main producing intervals of this reservoir, Khuff B and Khuff C, have tested high quantity of condensate-rich gas. Khuff reservoir consists mainly of dolomite and limestone sections with streaks of shale and anhydrite that constitute the nonpermeable and possible fracture barrier zones. The reservoir extends up to several hundred feet in thickness with varying quality and production potential. A careful planning of completion technique and choice of stimulation is important for efficient fracture coverage and improved hydrocarbon recovery. This paper addresses the general methodology of selecting perforation intervals and stimulation technique to develop and enhance production in the Khuff carbonate gas reservoir.
The effect of test conditions on the early components of the averaged electroencephalic response.

The effect of test conditions on the early components of the averaged electroencephalic response was examined in 12 normal hearing subjects between the ages of 21 and 43. Clicks at 50 dB SL were pr...
Synthesis, Characterization, and Electrochemistry of Heterometallic Dendrimers.

A method for the synthesis of new heterometallic dendritic molecules containing organoplatinum centers is reported. Reaction of Pt2Me4(μ-SMe2)2 with bpy-Fc2 (1) (bpy-Fc2 = 4,4‘-bis(ferrocenylvinyl)-2,2‘-bipyridine) gave the platinum(II) complex PtMe2(bpy-Fc2) (2). Complex 2 undergoes oxidative addition with iodomethane to yield PtMe3I(bpy-Fc2) (3) and with bis(bromomethyl)benzenes to yield complexes of the type [PtMe2Br(bpy-Fc2)CH2−]2R (4, R = 1,2-C6H4; 5, R = 1,3-C6H4; 6, R = 1,4-C6H4). 1, 3, and 4 were characterized by X-ray structure determinations. For 1, a = 11.780(3) A, b = 10.662(3) A, c = 11.642(3) A, β = 118.61(2)°, and V = 1283.7(6) A3 while, for 2, a = 11.497(2) A, b = 22.796(6) A, c = 15.801(3) A, β = 106.08(1)°, and V = 3979(2) A3. Only poor quality crystals of 4 could be obtained resulting in a partial structure refinement with a = 14.46(1) A, b = 15.14(1) A, c = 21.32(2) A, α = 69.45(4)°, β = 71.14(5)°, γ = 81.86(5)° and V = 4140(6) A3. The preferred conformation for 1 places the the bipyri...
Syntheses and characterization of novel biostable polyisobutylene based thermoplastic polyurethanes

Abstract The synthesis of polyisobutylene (PIB) based thermoplastic polyurethanes (TPU) with enhanced mechanical properties have been accomplished using poly(tetramethylene oxide) (PTMO) as a compatibilizer. PIB TPUs with Shore 60–100 A hardness were prepared by employing PIB diols (hydroxyallyl telechelic PIBs) for the soft segment and 4,4′-methylenebis(phenylisocyanate) (MDI) and 1,4-butanediol (BDO) for the hard segment. The TPUs exhibited number average molecular weight (Mn) in the range of 83,000–110,000 g/mol with polydispersity indices (PDIs) = 1.8–3.1. These TPUs, however, were inferior compared to commercial TPUs such as Pellethane™ (Dow Chemical Co.) as they exhibited low tensile strength (6–15 MPa) and/or ultimate elongation (30–400%). Processing of the harder compositions was also difficult and some could not be compression molded into flat sheets for testing. Differential Scanning Calorimetry (DSC) showed the presence of high melting (≥200 °C) crystalline hard segments suggesting longer – MDI–BDO – sequences than expected based on the stoichiometry. Easily processable TPUs with excellent mechanical properties (tensile strength up to 40 MPa, ultimate elongation up to 740%) were obtained by incorporating PTMO in the soft segment. Examination of PIB–PTMO TPUs with varying hard: soft compositions (20:80, 35:65 and 40:60 wt:wt) and Shore hardness (60 A, 80 A and 95 A) indicated that substituting 10–30 wt% of PIB diol with PTMO diol is sufficient to reach mechanical properties similar to Pellethanes.
Voltage-activated proton currents in human THP-1 monocytes.

Depolarization-activated H+-selective currents were studied using whole-cell and excised-patch voltage clamp methods in human monocytic leukemia THP-1 cells, before and after being induced by phorbol ester to differentiate into macrophage-like cells. The H+ conductance, gH, activated slowly during depolarizing pulses, with a sigmoidal time course. Fitted by a single exponential following a delay, the activation time constant, tauact was roughly 10 sec at threshold potentials, decreasing at more positive potentials. Tail currents upon repolarization decayed mono-exponentially at all potentials. The tail current time constant, tautail, was voltage dependent, decreasing with hyperpolarization from 2-3 sec at 0 mV to approximately 200 msec at -100 mV. Surprisingly, although tauact depended strongly on pHo, tautail was completely independent of pHo. H+ currents were inhibited by Zn2+. Increasing pHo or decreasing pHi shifted the voltage-activation relationship to more negative potentials, tending to activate the gH at any given voltage. Studied in excised, inside-out membrane patches, H+ currents were larger and activated much more rapidly at lower bath pH (i.e., pHi). In THP-1 cells differentiated into macrophages, the H+ current density was reduced by one-half, and tauact was slower by about twofold. The properties of H+ channels in THP-1 cells and in other macrophage-related cells are compared.
Changes in substrate specificity of the recombinant form of phenol sulfotransferase IV (tyrosine-ester sulfotransferase)

The over-expression of mammalian enzymes in bacterial systems by means of recombinant DNA technology has provided the enzymologist with a supply of catalyst sufficiently abundant to identify suboptimal substrates. Such large quantities are particularly useful when working with the enzymes of detoxication, a family of proteins that are distinguished by their broad substrate specificity for generally lipophilic compounds, i.e., by their very low specificity for features other than the functional group [1]. We have achieved bountiful expression of a sulfotransferase active with phenols [2], an enzyme originally purified and characterized from rat liver [3], and classified as tyrosine-ester sulfotransferase, EC 2.8.2.9 [4,5], but usually referred to as rat liver phenol or aryl sulfotransferase IV. Having improved the sensitivity and versatility of some of the assays for sulfotransferases, we examined the substrate spectrum of this enzyme. As presented here, the results of this examination point to the limitations of enzyme nomenclature and to the danger of equating enzymes isolated from their normal habitat with those formed by recombinant technology in a foreign cell. Our experiments also establish a greater catalytic scope for the natural rat liver enzyme than that previously described.
Phase Retrieval By Optical Phase Differentiation

A phase retrieval technique utilizing a differentiation filter in a coherent processing system has been developed and tested. The image irradiance produced in this system is quadratic in the partial derivative of object phase with respect to an object coordinate parallel to the transmittance gradient of the filter. Given a properly chosen set of such image irradiances it is possible to solve for the object phase.
Performance analysis of a photonic single-hop ATM switch architecture, with tunable transmitters and fixed frequency receivers

Abstract We consider a photonic asynchronous transfer mode (ATM) switch based on the single-hop wavelength division multiplexing (WDM) architecture with tunable transmitters and fixed frequency receivers. The switch operates under a schedule that masks the transceiver tuning latency. We analyze approximately a queueing model of the switch in order to obtain the queue-length distribution and the cell-loss probability at the input and output ports. The analysis is carried out assuming two-state Markov modulated Bernoulli process (MMBP) sources that capture the notion of burstiness and correlation, two important characteristics of ATM traffic, and non-uniform destination probabilities. We present results which establish that the performance of the switch is a complex function of a number of system parameters, including the load balancing and scheduling algorithms, the number of available channels, and the buffer capacity. We also show that the behavior of the switch in terms of cell-loss probability as these parameters are varied cannot be predicted without an accurate analysis. Our work makes it possible to study the interactions among the system parameters, and to predict, explain, and fine tune the performance of the switch.
Conversion of wastewater organics into biodiesel feedstock through the predator-prey interactions between phagotrophic microalgae and bacteria

We herein report a new route of cultivating phagotrophic microalgae with wastewater for biodiesel feedstock production. A continuous-flow process has been developed, through which organic matter of wastewater is first converted into the biomass of bacteria and then the bacteria are consumed by phagotrophic microalgae for growth and lipid production.
Characterization of tongue shape

Mathematical techniques are described for analyzing tongue shapes obtained with ultrasound images. The surface of the mid-sagittal section of the tongue was approximated by discrete points. In turn, these points were used to approximate position, slope and curvature of the tongue surface at a fixed time during speech. Two approaches were employed. The first method involved the use of finite difference approximations to derivatives of the function of tongue position. The second utilized a curve fit. Both methods were examined for reliability. Results of these analyses on a simple, single speech sound are discussed.
The Deadliest Sin: Warnings against Avarice and Usury on Romanesque Capitals in Auvergne

Clustered around the episcopal center of Clermont, in that least accessible French province of Auvergne, a series of romanesque churches built between the end of the eleventh and first half of the twelfth centuries harbor sculptured capitals which repeatedly treat the themes of avarice and usury. Although the virtues and vices provided a popular and graphic subject for sculptors throughout France during this period, only in Auvergne do we discover such a specific emphasis on the sins of avarice and usury. In some cases the subject is treated to the exclusion of all others, and every example has been placed in a predominant and highly visible location within the church.
Identification and characterization of novel AML1-ETO fusion transcripts in pediatric t(8;21) acute myeloid leukemia: a report from the Children's Oncology Group

Identification and characterization of novel AML1-ETO fusion transcripts in pediatric t(8;21) acute myeloid leukemia: a report from the Children's Oncology Group
Residential Energy Consumption: 1987 to 1997

The purpose of this study was to examine energy-conserving practices and consumption from 1987 to 1997 using a human ecosystem framework. Research on energy consumption and practices at the household level has been minimal in recent years. Factors that influence household energy consumption were examined, including climate, demographic characteristics of the households, housing characteristics including weatherization features and appliances, and occupant behaviors. This study was a secondary analysis of data compiled by the Energy Information Administration from the 1987, 1990, 1993, and 1997 Residential Energy Consumption Surveys and included only owner-occupied, single-family detached residences. Based on multiple regression analyses, more than 30% of the household energy consumption was accounted for by the variables representing the environments of the human ecosystem.
Expression of Adh8 mRNA is developmentally regulated in Japanese medaka (Oryzias latipes)

We cloned two full-length alcohol dehydrogenase (ADH) cDNAs from the liver tissue of adult Japanese medaka (Oryzias latipes). The coding regions spanned 1134 and 1137 nucleotides (nt) and the deduced amino acid sequences shared 63.6% identity between them. Phylogenetic analysis of the deduced amino acid sequence data identified the 1137nt as an orthologue of mammalian Adh5 (Class III) and the 1134 nt as an ortholog of zebrafish Adh8 genes. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis further showed that adult medaka Adh5 mRNA was expressed in all the organs tested (brain, eye, gill, GI, heart, liver, kidney, muscle, skin, spleen, testis and ovary) while Adh8 mRNA showed tissue-specific expression (eye, GI, liver, kidney, muscle and skin). Comparison of the Adh5 and Adh8 mRNA expression in eye, gill, liver, kidney and skin indicate that Adh8 mRNA copy numbers are higher in all these tissues compared to Adh5 mRNA expression. Both Adh5 and Adh8 mRNAs are expressed during embryonic development with Adh5 mRNA transcripts present with very high copy number throughout the development. However, Adh8 mRNA is expressed in very low copy numbers initially (∼1 h post fertilization; hpf) but begin to increase from 48 hpf to a level of ∼200-fold higher at hatching. Therefore, it appears that in Japanese medaka, the expression of Adh8 mRNA, not Adh5 mRNA, is developmentally regulated.
Vertical electronic transport in novel semiconductor heterojunction structures

Abstract The investigation of vertical transport in semiconductor heterojunction systems has recently undergone a renaissance due to improved epitaxial techniques in a number of material systems. By using resonant tunneling, we can perform electronic spectroscopy not only of the double barrier structure itself, but of any system (with quantized well states) suitably coupled to a resonant tunneling spectrometer. In designing such systems, an important degree of freedom is introduced by utilizing multi-component structures; for example, a GaAs contact — AlGaAs barrier — InGaAs quantum well. In this structure, the high electron affinity of the quantum well creates a “deep” quantum well, in which we demonstrate that quantum well states can be hidden from transport. Finally, we present results from microfabricated quantum well structures (“quantum dots”) which are sufficiently small in the lateral dimension to introduce size effects. Telegraph noise due to the lateral size of these structures has been observed, and the first indications of lateral quantization in all three dimensions in a semiconductor quantum well are presented.
Heuristics and normative models of judgment under uncertainty

Abstract Psychological evidence shows that probability theory is not a proper descriptive model of intuitive human judgment. Instead, some heuristics have been proposed as such a descriptive model. This paper argues that probability theory has limitations even as a normative model. A new normative model of judgment under undertainty is designed under the assumption that the system's knowledge and resources are insufficient with respect to the questions that the system needs to answer. The proposed heuristics in human reasoning can also be observed in this new model, and can be justified according to the assumption.
SIGCHI Social Impact Award

SIGCHI Social Impact Award is given to individuals who promote the application of human-computer interaction research to pressing social needs. The recipient will have past or current work within the HCI profession that demonstrates social benefit. Example criteria include: Facilitating use of computer and telecommunication technology by diverse populations. Increasing access to technology for those with limited educational opportunities. Reducing economic barriers for access to information and communication technologies. Promoting privacy, security, trust, and safety. Improving medical care, education, housing, water supplies, and nutrition. Supporting technologies for international development and conflict resolution. Improving human communication and reducing isolation. Reasonably active participant in the ACM SIGCHI community, although outstanding individuals active in other professional communities are considered. Crisis informatics addresses socio-technical concerns in large-scale emergency response. Additionally it expands consideration to include not only official responders (who tend to be the focus in policy and technology-focused matters), but also members of the public. It therefore views emergency response as a much broader socio-technical system where information is disseminated within and between official and public channels and entities. Crisis informatics wrestles with methodological concerns as it strives to develop new theory and support informed development of ICT and policy. Palen will describe the range of work her team has engaged in at CU-Boulder since 2006, and highlight the different branches of crisis informatics research through discussion of the multidisciplinary research they have conducted here. BIO:Leysia Palen is an Associate Professor of Computer Science at the University of Colorado Boulder. She is a faculty fellow with the ATLAS Institute and the Institute of Cognitive Science. She is also a Full Adjunct Professor at the University of Agder in Norway. Leysia Palen is a graduate of the University of California, San Diego with a BS in Cognitive Science, and of the University of California, Irvine with an MS and PhD in Information and Computer Science. Prof. Palen is a leader in the area of crisis informatics, an area she forged with her graduate students and colleagues at CU-Boulder. She brings her training in human-computer interaction (HCI), computer-supported cooperative work and social computing to bear on understanding and advancing socio-technical issues of societal import. Prof. Palen is the author of over 70 articles and a co-edited book in the areas of human computer interaction, computer supported cooperative work, mobility, and crisis informatics. She was awarded an NSF CAREER in 2006. She is an Associate Editor for the Human Computer Interaction Journal (Taylor and Francis) and for the Computer-Supported Cooperative Work Journal (Springer).
Immune response to minor variant antigen types (VATs) in a mixed VAT infection of the African trypanosomes

Summary It has been shown that soon after the onset of acute infection with Trypanosoma brucei gambiense, mice are able to detect immunologically small numbers of minor variant antigen types (VATs) within the population. However, in more longstanding infections, considerably larger populations of minor VATs are required to stimulate an effective immune response. As a result, larger populations of minor VATs evade immune detection and, following a decrease in parasitaemia, become part of the relapse population. We hypothesize that the development of immunosuppression increases the effectiveness of antigenic variation as an escape mechanism.
Intracellular zinc fluxes associated with apoptosis in growth plate chondrocytes.

Matrix vesicles released by epiphyseal growth plate chondrocytes are known to contain a significant quantity of labile Zn 2 + . Zonal analysis of chicken metatarsal bones showed that the resting/proliferative region of thegrowth plate contained high levels of Zn 2 + with significantly lower levels in the hypertrophic cartilage suggesting a loss of cellular Zn 2 + as the chondrocytes mature. Intracellular labile Zn 2 + was measured in primary cultures of growth plate chondrocytes by assay with the fluorescent Zn-chelator toluenesulfonamidoquinoline (TSQ) and imaged by multi-photon laser scanning microscopy (MPLSM) with the TSQ derivative zinquin. Short-term exposure to Zn 2 + , both in the presence and absence of pyrithione resulted in significant increases in cytosolic Zn 2 + . Treatment with the membrane-permeant Zn 2 + chelator TPEN rapidly reduced the levels of labile Zn 2 + and triggered apoptosis. Cytosolic Zn 2 + levels were significantly reduced following 24-h incubations with known inducers of chondrocyte apoptosis. The loss of intracellular Zn 2 + was accompanied by a significant reduction in the cytosolic metal-binding protein metallothionein. Examination of Zn 2 + -treated cells with MPLSM showed uniformly higher zinquin fluorescence. Treatment of Zn 2 + -loaded cells with TPEN quenched zinquin fluorescence confirming that the observed fluorescence in chondrocytes is due to the presence of intracellular Zn 2 + . A dose-dependent increase in zinquin fluorescence was observed in cells treated with a range of Zn 2 + concentrations. Short-term treatment of cultured chondrocytes with apoptosis-inducing chemicals resulted in transient increases in intracellular labile Zn 2 + . These results indicate that Zn 2 + is mobilized from intracellular binding sites in the early stages of chondrocyte apoptosis and is subsequently lost from the cells. The early mobilization of Zn 2 + pro vides a mechanism for its movement to matrix vesicles and the extracellular matrix.
On a two-step estimation of a multivariate logit model

Abstract In this article the author studies the properties of the two-step estimation method proposed by Domencich and McFadden ( Urban Travel Demand , North-Holland, 1975) for a multivariate logit model and shows that it is consistent but asymptotically less efficient than the maximum likelihood estimator. Its computation, however, can be considerably simpler than that of the maximum likelihood estimator, especially in models involving several dependent variables.
Quantitative assessment of DNA fragmentation and beta-amyloid deposition in insular cortex and midfrontal gyrus from patients with Alzheimer's disease

It has been suggested that the neurodegeneration that occurs with Alzheimer's disease (AD) may result from apoptosis, a process of programmed cell death. Neuronal injury, induced by abnormal aggregates of beta-amyloid peptide, has been identified as an apoptotic trigger. In the present study, brain tissue samples were obtained from the insular cortex (INS) and midfrontal gyrus (MFG) of Alzheimer subjects and age-matched, nondemented controls. Tissue sections from all samples were alternately stained by an in situ TUNEL assay to identify 3' termini DNA strand breaks characteristic of apoptosis or immunohistochemically for beta-amyloid deposition in senile plaques. The incidence of DNA fragmentation detected in pyramidal neurons was relatively infrequent overall, but was significantly higher in AD compared to controls. AD subjects consistently exhibited a dense accumulation of plaques, with a twofold greater concentration in MFG as INS. There was no significant difference in pyramidal cell number regardless of subject or brain region. Taken together, our results indicate that the TUNEL assay may be revealing cell damage rather than cell loss. Our finding of a moderate correlation between the incidence of TUNEL-positive cells and plaque density implicates beta-amyloid as one of multiple factors provoking cell injury in AD. A notable contribution of this study is the identification of distinctive neuropathologies co-occurring in two brain regions interconnected with each other and with limbic and cortical areas typically damaged during AD.
The synthesis and characterization of zinc ferrite aerogels prepared by epoxide addition

Over the past decade sol–gel methods have become increasingly popular alternatives to the solid state synthesis of metal oxides. In many cases sol–gel synthesis is preferred due to desirable physical properties such as high surface area, high porosity, and small crystallite size. Monolithic zinc ferrite aerogels were produced by the epoxide addition sol–gel method. It was observed that addition of propylene oxide to 2-propanol solution of either the hydrated metal nitrate salts or the hydrated metal chloride salts resulted in the formation of stable red–brown gels. Aerogels were characterized using powder X-ray diffraction, high resolution scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption/desorption analysis. The metal salt used in the synthesis was found to significantly influence the properties of the aerogel. All aerogels synthesized exhibited low densities and high surface areas (>340 m2/g). Annealing of the aerogel at relatively low temperatures (below 450 °C) yielded a highly crystalline porous material which is composed of nanometer sized particles.
Nitrogen cycling in desert biological soil crusts across biogeographic regions in the Southwestern United States

Biological soil crusts (BSCs) are thought to be important in the fertility of arid lands as gateways for carbon (C) and nitrogen (N). Studies on the Colorado Plateau have shown that an incomplete internal N cycle operates in BSCs that results in significant exports of dissolved organic N, ammonia and nitrate into the bulk soil through percolating water, thus mechanistically explaining their role as a N gateway. It is not known if this pattern is found in other arid regions. To examine this, we measured rates of major biogeochemical N-transformations in a variety of BSCs collected from the Colorado Plateau and the Mojave, Sonoran and Chihuahuan Deserts. Dinitrogen fixation and aerobic ammonia oxidation were prominent transformations at all sites. We found anaerobic ammonia oxidation (anammox) rates to be below the detection limit in all cases, and at least 50-fold smaller than rates of N2-fixation, making it an irrelevant process for these BSCs. Heterotrophic denitrification was also of little consequence for the flow of N, with rates at least an order of magnitude smaller than those of N2-fixation. Thus we could confirm that despite the demonstrable differences in microbial community composition and soil material, BSCs from major biogeographic regions in arid North America displayed a remarkably consistent pattern of internal N cycling. The implications for arid land fertility drawn from previous studies in the Colorado Plateau appear applicable to BSCs across other arid regions of the Southwestern United States.
Improvements in modeling EXAFS with many-pole self-energy and FEFF 8.5

While theoretical standards such as those from FEFF have many advantages for EXAFS analysis, the quality of fit statistics and estimation of parameter uncertainties has always been somewhat problematic using them. Even though the calculations reproduce EXAFS features sufficiently well to give bond distances accurate to 0.01A or so, fits to high-quality experimental spectra will have fit residuals far larger than the experimental uncertainties. One of the possible causes for this mis-fit is from approximations made in the phenomenological calculations of the inelastic losses, though this has been difficult to test conclusively in the past. Recent improvements in calculations of inelastic losses using a many-pole self-energy (MPSE) using a real-space calculation of the dielectric function have been shown to give significant improvements in XANES calculations. Here, we discuss the use of MPSE calculations for EXAFS analysis, and show that these calculations from FEFF8.5 can quantitatively improve fit quality for EXAFS, reducing mis-fits by a factor of 2 or more compared to FEFF6. This approach may also allow the semi-physical fit parameter S02 to be avoided. The implications for improving precision for EXAFS analysis and the nature of the remaining fit residual are discussed.
Hard breakup of the deuteron into two Δ isobars

We study high-energy photodisintegration of the deuteron into two $\ensuremath{\Delta}$ isobars at large center of mass angles within the QCD hard rescattering model (HRM). According to the HRM, the process develops in three main steps: the photon knocks a quark from one of the nucleons in the deuteron; the struck quark rescatters off a quark from the other nucleon sharing the high energy of the photon; then the energetic quarks recombine into two outgoing baryons which have large transverse momenta. Within the HRM, the cross section is expressed through the amplitude of $\mathit{pn}\ensuremath{\rightarrow}\ensuremath{\Delta}\ensuremath{\Delta}$ scattering which we evaluated based on the quark-interchange model of hard hadronic scattering. Calculations show that the angular distribution and the strength of the photodisintegration is mainly determined by the properties of the $\mathit{pn}\ensuremath{\rightarrow}\ensuremath{\Delta}\ensuremath{\Delta}$ scattering. We predict that the cross section of the deuteron breakup to ${\ensuremath{\Delta}}^{++}{\ensuremath{\Delta}}^{\ensuremath{-}}$ is 4--5 times larger than that of the breakup to the ${\ensuremath{\Delta}}^{+}{\ensuremath{\Delta}}^{0}$ channel. Also, the angular distributions for these two channels are markedly different. These can be compared with the predictions based on the assumption that two hard $\ensuremath{\Delta}$ isobars are the result of the disintegration of the preexisting $\ensuremath{\Delta}\ensuremath{\Delta}$ components of the deuteron wave function. In this case, one expects the angular distributions and cross sections of the breakup in both ${\ensuremath{\Delta}}^{++}{\ensuremath{\Delta}}^{\ensuremath{-}}$ and ${\ensuremath{\Delta}}^{+}{\ensuremath{\Delta}}^{0}$ channels to be similar.
Freeze-fracture studies of tubular myelin and lamellar bodies in fetal and adult rat lungs.

Rat lungs were freeze-fractured to determine the structure of lamellar bodies (LBs) and of tubular myelin (TM) which are believed to be pulmonary surfactant. When intraalveolar TM is broken across its length, fractures expose a square lattice, similar to that previously described in thin sections of lung tissues. A fracture which cleaves TM membranes within their interiors and which is propagated along the tubule length exposes rows of particles which frequently coincide with the corners of the tubules as shown when a longitudinal fracture is diverted to a cross-fracture. In contrast, intracellular and most intraalveolar LBs are composed of smooth, generally particle-free, surfaces; thus LB membranes become particulate when they are converted into TM. The source and the chemical nature of the particles is unknown. The observations suggest that procedures used to prepare lung tissues for thin-sectioning do not generate TM or greatly alter its fine structure.
Spontaneous progressive multifocal leukoencephalopathy (PML) in macaques

PROGRESSIVE multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system (CNS) which has so far been recognised only in man1,2. Although it is an infrequent cause of clinical neurological disorder3, it is of particular interest because of its frequent association with diseases in which immunological competence is impaired4–7, and because it is the only chronic demyelinating disease of man in which a virus (papovavirus) has been consistently demonstrated4,5,8,9. So far, efforts to transmit the disease to non-human primates have failed8. This report of a spontaneous disease in macaques with striking similarities to PML seems to be the first recorded instance of such a condition in animals.
Population density and row spacing effects on dry matter yield and bark content of kenaf (Hibiscus cannabinus L.)

Abstract Efforts to bring kenaf from experimental crop status to an accepted alternative in established cropping systems have been ongoing for years. To compete with existing crops and maximize monetary returns, the effects of agronomic practices on yield and crop quality must be better understood. Row spacing and population density are implicated in dry matter yield, and therefore, bast fiber production. Four row spacings, four population densities, and two cultivars were examined to determine these effects on dry matter accumulation and bark content. Of all factors evaluated, only row spacing significantly affected dry matter yield. Yield was greatest at the 35.5-cm row spacing, and lowest at the 71- and 101.6-cm row spacings. With regard to bast yield, calculated as a percentage of total sample dry weight, a significant cultivar × row spacing interaction occurred. However, data indicate that manipulating row spacing to maximize total stalk yield per hectare resulted in the highest bast fiber yield for the two cultivars tested. The narrowest row spacing of 35.5 cm, gave the greatest biomass yield as well as the highest bark yield per hectare.
Imaging And Coherency In Complex Structures

In complex structures, more than one pair of rays may connect a source and receiver via a scattering point. Whenever many such pairs of rays exist and have the same two-way traveltime, an inherent ambiguity appears in the inverse scattering process. Unless a simple ray geometric condition is met, the migrated section will contain images that need not belong to the actual reflectivity field. The geometric requirement relates to the acquisition geometry, and it is almost always satisfied when the sources and receivers both cover an area. Even if the geometric requirment is satisfied for the acquisition geometry, it may not be so for single source experiments (different acquisition geometry) consequently coherency panels may not be flat, even if one migrates with the exact background velocity.
The Legal Cartography of Colonization, the Legal Polyphony of Settlement: English Intrusions on the American Mainland in the Seventeenth Century

This essay investigates the first century of English colonization of the North American mainland, concentrating on the charters and letters patent that proponents of western planning secured over the course of the century. The elaborated legalities of chartering should be understood as a technology of planning and design. Charters allowed projectors both to justify their pursuit of particular territorial claims and to establish, with some precision, the conceptions of the appropriate, familiar, desired order of things and people that would be imposed onto uncharted social and physical circumstance. The structures of authoritative sociolegal order planned by projectors encountered others implicit in the migrations of actual settlers. Investigating settlers' disagreement with and departure from projectors' designs, the essay discards common explanations—that these were inevitable corrections brought about by the intrusion of local environmental realities on English projectors' fantasies, or the realization of an implicit evolutionary logic of political development, or of legal reception. It argues that disagreements were more often the result of a collision of distinct English legal cultures brought, by migration, into an unavoidable proximity. The essay counterposes the paradigm of “colonization” to both “common law reception” and “bottom-up localism” analyses of the formation of early American legal culture. It proposes that “colonization” also resolves the discontinuity between early (colonial) and later (U.S.) American history.
The effect of RNA interference down-regulation of RNA editing 3'-terminal uridylyl transferase (TUTase) 1 on mitochondrial de Novo protein synthesis and stability of respiratory complexes in Trypanosoma brucei

Inhibition of RNA editing by down-regulation of expression of the mitochondrial RNA editing TUTase 1 by RNA interference had profound effects on kinetoplast biogenesis in Trypanosoma brucei procyclic cells. De novo synthesis of the apocytochrome b and cytochrome oxidase subunit I proteins was no longer detectable after 3 days of RNAi. The effect on protein synthesis correlated with a decline in the levels of the assembled mitochondrial respiratory complexes III and IV, and also cyanide-sensitive oxygen uptake. The steady-state levels of nuclear-encoded subunits of complexes III and IV were also significantly decreased. Because the levels of the corresponding mRNAs were not affected, the observed effect was likely due to an increased turnover of these imported mitochondrial proteins. This induced protein degradation was selective for components of complexes III and IV, because little effect was observed on components of the F1·F0-ATPase complex and on several other mitochondrial proteins.
Substance and process in the development of party systems in East Central Europe

Abstract What conditions in post-communism affect the rise of competitive political parties capable of providing significant options to the electorate? The initial wisdom held that numerous weaknesses of political society in East Central Europe impeded the consolidation of a stable party system. More recently, two distinct schools emerged to present a more structured view of political space. One relies on a substantive evaluation of political cleavages, ideological posturing, and issue relevance to map party positions and voter placements in post-communist politics. This approach concentrates on emerging social and economic cleavages as the foundation of party systems. The second approach focuses on a process perspective that looks to political mechanisms such as elections and coalition formation that act as a funnel for the formation of new party systems. This article combines the substantive and process understandings of political choice to provide a comprehensive analysis of the transformation of party systems in post-communist states. The concentration is both on the demand side of the electoral process, i.e. the formation of cleavages among the electorate, and on the supply side, i.e. the channeling of political options through institutional mechanisms. Together, the process of party evolution and the substance of party differentiation help to define the hegemonic, polarized, fragmented, and pluralist phases in the consolidation of party systems in post-communism.
Bioreduction of Nitrobenzene, Natural Organic Matter, and Hematite by Shewanella putrefaciens CN32

We examined the reduction of nitrobenzene by Shewanella putrefaciens CN32 in the presence of natural organic matter (NOM) and hematite. Bioreduction experiments were conducted with combinations and varied concentrations of nitrobenzene, soil humic acid, Georgetown NOM, hematite, and CN32. Abiotic experiments were conducted to quantify nitrobenzene reduction by biogenic Fe(II) and by bioreduced NOMs. We show that S. putrefaciens CN32 can directly reduce nitrobenzene. Both NOMs enhanced nitrobenzene reduction and the degree of enhancement depended on properties of the NOMs (aromaticity, organic radical content). Hematite enhanced nitrobenzene reduction by indirect reaction with biogenic-Fe(II), however, enhancement was dependent on the availability of excess electron donor. Under electron donor-limiting conditions, reducing equivalents diverted to hematite were not all transferred to nitrobenzene. In systems that contained both NOM and hematite we conclude that NOM-mediated reduction of nitrobenzene was more important than Fe(II)-mediated reduction.
A schooling on their implications for software engineering [trends]

A discussion is presented on trends in software engineering. This can be done by simply extrapolating some of the popular, current trends. And, in fact, we examine a few of these obvious indicators. However, software engineering has had new approaches that are more revolutionary than evolutionary. In particular, we try to discern trends in software engineering based on trends in delivered software systems.
Projected National Impact of Colorectal Cancer Screening on Clinical and Economic Outcomes and Health Services Demand

Background & Aims: Colorectal cancer (CRC) screening is effective and cost-effective, but the potential national impact of widespread screening is uncertain. It is controversial whether screening colonoscopy can be offered widely and how emerging tests may impact health services demand. Our aim was to produce integrated, comprehensive estimates of the impact of widespread screening on national clinical and economic outcomes and health services demand. Methods: We used a Markov model and census data to estimate the national consequences of screening 75% of the US population with conventional and emerging strategies. Results: Screening decreased CRC incidence by 17%–54% to as few as 66,000 cases per year and CRC mortality by 28%–60% to as few as 23,000 deaths per year. With no screening, total annual national CRC-related expenditures were $8.4 billion. With screening, expenditures for CRC care decreased by $1.5–$4.4 billion but total expenditures increased to $9.2–$15.4 billion. Screening colonoscopy every 10 years required 8.1 million colonoscopies per year including surveillance, with other strategies requiring 17%–58% as many colonoscopies. With improved screening uptake, total colonoscopy demand increased in general, even assuming substantial use of virtual colonoscopy. Conclusions: Despite savings in CRC care, widespread screening is unlikely to be cost saving and may increase national expenditures by $0.8–$2.8 billion per year with conventional tests. The current national endoscopic capacity, as recently estimated, may be adequate to support widespread use of screening colonoscopy in the steady state. The impact of emerging tests on colonoscopy demand will depend on the extent to which they replace screening colonoscopy or increase screening uptake in the population.
Quality Uncertainty, Procurement Strategies, and Grain Merchandising Risk: Vomitoxin in Spring Wheat

This study analyzes implications of a random quality factor, vomitoxin, on spatial flows and merchandising risk. Vomitoxin poses major risks for grain traders because of contract specifications, regulatory limits, sampling difficulties, and imprecise measurement. The effect of these were analyzed using crop quality and market data for the U.S. spring wheat crop, which has been severely affected by vomitoxin infestations during the 1990s. The analysis was structured as a blending problem with the objective of maximizing the net value of wheat sales. Relationships among market price spreads and contract specifications are interesting and their effects are demonstrated through simulations.
Synthesis of positively charged silver nanoparticles via photoreduction of AgNO3 in branched polyethyleneimine/HEPES solutions.

Branched polyethyleneimine (BPEI) and 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) were used collaboratively to reduce silver nitrate under UV irradiation for the synthesis of positively charged silver nanoparticles. The effects of molar ratio of the ingredients and the molecular weight of BPEI on the particle size and distribution were investigated. The mechanism for the reduction of Ag+ ions in the BPEI/HEPES mixtures entails oxidative cleavage of BPEI chains that results in the formation of positively charged BPEI fragments enriched with amide groups as well as in the production of formaldehyde, which serves as a reducing agent for Ag+ ions. The resultant silver nanoparticles are positively charged due to protonation of surface amino groups. Importantly, these positively charged Ag nanoparticles demonstrate superior SERS activity over negatively charged citrate reduced Ag nanoparticles for the detection of thiocyanate and perchlorate ions; therefore, they are promising candidates for sens...
Thermal and photic preferences in intact and parietalectomized Anolis carolinensis

Adult female Anolis carolinensis were exposed to combinations of thermal and photic stimuli to test the relative importance of these stimuli to the parietal eye, a photoreceptive structure apparently controlling exposure to sunlight and, perhaps, directly influencing behavioral temperature selection. Exposure to a cool light source occurs significantly less often in sham-parietalectomized than in parietalectomized animals, and both groups are photophobic if the light source does not provide heat. Parietalectomized animals congregate around a heat source significantly more often than do intact controls, which gather in a cool dark area significantly more often than near a thermal source. Based upon these responses, it appears that parietal eyed animals are more thermophilic than photophilic, precisely choosing appropriate photothermal positions. Parietalectomy alters these behavioral responses and results in increased exposure to thermal and light sources, although attraction to a thermal source is much more pronounced than attraction to a light source. Because parietalectomized animals become even more thermophilic than sham-parietalectomized controls, but are comparably photo-phobic, it seems reasonable that increased exposure to sunlight after parietalectomy is not a response to a light stimulus, but is, instead, a response to the thermal characteristics of solar radiation. The parietal—pineal complex may have a more important role in behavioral temperature regulation than has previously been suggested.
Recent trends in UN human rights activity: description and polemic

How have UN human rights goals and priorities evolved in the 1970s? The moderate compromise represented by the International Bill of Rights, as completed by the Covenants in 1966, has been undone in the seventies. A point-by-point examination of the major principles enunciated in General Assembly resolution 32/130 of 16 December 1977, which codified the trends of the decade and stands as the authoritative statement of the UN's strategic goals and priorities in the field of human rights, shows that the earlier moderation has been replaced by a one-sided, politicized, and often cynical approach. This development in UN doctrine merits polemical criticism.
USDA Options for Regulatory Changes to Enhance the Prevention and Control of Avian Influenza

During the past decade, several examples of the ability of H5 and H7 low-pathogenicity avian influenza (LPAI) viruses to mutate to high-pathogenicity (HP) viruses have been documented worldwide. During this time, the introduction and persistence of an H7N2 LPAI virus in the northeast live-bird marketing system in the United States has raised concern on how to prevent the possibility of such a mutation occurring in this country. The United States has periodically experienced trade restrictions based on the occasional introduction of H5 and H7 LPAI viruses into commercial poultry and based on AI-related changes in the import requirements for poultry and poultry products of several of our trading partners. Consequently, the U.S. Department of Agriculture (USDA) is exploring options for how our regulatory response to H5 and H7 LPAI viruses might be revised to better protect our domestic poultry flocks from HPAI and to ensure that any interruptions in trade are scientifically supportable. The options under consideration include mandatory and voluntary measures to improve the surveillance for and control of H5 and H7 LPAI virus infections.
Microelectromechanical systems: interfacing electronics to a non-electronic world

Microelectromechanical systems (MEMS) merging integrated sensors, microactuators, and low-power electronics are rapidly growing in sophistication. Projection displays, IR/thermal imagers, print heads, microphones, accelerometers and gyros are all emerging based on this technology. Using embedded microprocessors, complete microsystems employing self-testing and digital compensation promise to achieve levels of reliability and accuracy previously impossible at low cost. Sensors for advanced semiconductor process tools, modules for distributed environmental monitoring, inertial-grade navigation aids, advanced security systems, and mass storage devices are a few of the applications being targeted. The technology choices, device structures, applications, and tradeoffs in this area are examined in this paper along with future challenges.