cssi/SciSciGPT-SciSciNet huggingface dataset:
Variation of serum creatinine, cystatin C, and creatinine clearance tests in persons with normal renal function

Abstract Background To determine the potential sensitivity of several renal function tests for detecting early changes in renal function, we compared the within-individual (W-I) variation over 5 months of serum creatinine, serum cystatin C, and creatinine clearance. Methods On 31 healthy subjects, blood and timed urine specimens were collected once each month to get 6 collections. Creatinine (enzymatic) in serum and urine and cystatin C (immunonephelometric) in serum were measured and glomerular filtration rate (GFR) by creatinine clearance and the Modification of Diet in Renal Disease (MDRD) equation were calculated. To compare W-I variations between different creatinine methods, we also measured creatinine by both enzymatic and kinetic alkaline picrate methods on 15 sets of frozen samples. Results For the 31 volunteers, the mean W-I variations for serum creatinine (5.8%) and cystatin C (5.4%) were both much lower than the W-I variation of creatinine clearance (18.7%). As expected, the MDRD GFR had a similar W-I variation (6.7%) to that of serum creatinine and its values were markedly different than GFR by creatinine clearance. On the 15 sets of frozen samples, the W-I variation of creatinine measured by the enzymatic method (CV 5.2%) was slightly less than by the picrate method (CV 6.2%). Conclusions The low W-I variation of both serum cystatin C and serum creatinine suggests that serial measurements of either would detect a changes in renal function earlier than would GFR by creatinine clearance or MDRD equation, which allows reporting only for GFRs 2 . While we measured only creatinine clearance, the large variability, difficulty, and cost of all clearance measurements make them impractical for routine monitoring of patients.
Knowledge resource exchange in strategic alliances

Strategic alliances are no longer a strategic option but a necessity in many markets and industries. Dynamic markets for both end products and technologies, coupled with the increasing costs of doing business, have resulted in a significant increase in the use of alliances. Yet, managers are finding it increasingly difficult to capture value from alliances. In this paper, we present a model that describes the knowledge resource exchange between alliance partners. This model focuses on the different dimensions of knowledge resources (tacitness, specificity, and complexity) and their associated value implications, as well as the different roles of the partner based on its position within an industry network (complementor, competitor, supplier, customer, or other). We also argue that in order to capture and internalize knowledge obtained through an alliance, a firm must have an alliance learning capability. We illustrate the use of this model in the computer industry by analyzing the publicly announced alliances of Dell Computer Corporation and Sun Microsystems, Inc. By applying our resource exchange model, we were able to analyze the alliance strategy for each firm and to understand the alignment between the announced business strategy and alliance strategy for each firm. The findings suggest that what is important is not necessarily a particular alliance strategy, but rather an alignment between alliance strategy and business strategy.
Donor MHC class I peptides in conjunction with self-epitopes induce donor-specific tolerance in a dose-dependent manner but unable to abrogate chronic rejection.

Abstract Understanding specific tolerance mechanisms is a primary goal of transplantation science. We have previously shown that hosts treated with MHC class I protein have donor sequences in the α 1 -helix of the α 1 domain on a background of self-epitopes, resulting in the development of donor-specific tolerance. However, the nature of class I alloantigenic determinants that regulate the alloimmune response remains unclear. The α 1 -helical sequence of RT1.A, l which shares RT1.A u sequences, was substituted in the RT1.A a molecule to produce the composite [α 1h l/u ]-RT1.A a MHC class I allochimeric molecule. Immunodominant epitopes were identified within the hypervariable region of the α 1 domain of RT1.A a (ACI), RT1.A l (Lewis, LEW), and RT1.A u (Wistar Furth [WF]). To clarify the mechanisms of tolerance development through presentation of donor-type immunogenic epitopes and cryptic self-epitopes we used synthetic peptides corresponding to donor immunogenic determinants with peptides derived from recipient self-sequences (RT1.A a —aa 10 to 49 P1 and 91 to 120 P3; and P2 RT1.A l/u 50 to 90). ACI recipients of LEW and WF cardiac allografts were injected through the portal vein (PV) at day 0 with four doses (2, 0.5, 0.25, and 0.125 mg/rat) of three peptide mixtures in conjunction with subtherapeutic CsA (10 mg/kg for 3 days). Allograft survival was strongly dose-dependent. Only low-dose regimens were consistent in tolerance induction, but such therapy did not abrogate development of chronic rejection (CR), unlike allochimeric therapy with soluble MHC class I protein. Different effects of protein or synthetic peptide therapies on development of CR suggest that development of specific tolerance is an active immunologic process and it depends on the form of allogeneic epitopes presented.
Underreporting of blood and body fluid exposures among health care students and trainees in the acute care setting: a 2007 survey.

Background It has been estimated that more than 8 million health care workers (HCWs) in the United States may be exposed to blood and body fluids via sharp and mucocutaneous exposures. Methods An anonymous questionnaire was distributed among 505 HCWs. The target sample population included all the medical students; nursing professionals; dental professionals; and residents in internal medicine, emergency medicine, surgery, and obstetrics and gynecology at the University of Illinois Medical Center, Chicago, Illinois, a metropolitan tertiary care and referral center for Northern Illinois and Northwest Indiana. The sample was limited by the number of HCWs who were available to take the survey. The number and the characteristics of occupational exposures and reporting practices were recorded and compiled. Subsequently, a review of the English literature was performed using PubMed to analyze reasons for underreporting. Secondary and tertiary articles were located based on findings from the initial searches. Results One hundred three of 455 (22.6%) HCWs reported a sharps exposure during their career, including their student years; thirty-four (33.0%) of these were not reported. One hundred five of 455 (23.1%) HCWs reported a mucocutaneous exposure during their career; 87 (82.9%) of these were not reported. The most common year of exposure was the intern year. The most common reason for not reporting was the belief that the exposure was not significant, followed by the combination of believing the exposure was not significant and being too busy. Conclusion Underreporting of blood and body fluid exposures is common because of a belief that most exposures are not significant. More education of HCWs is needed to change this perspective.
Studies on amylo-1, 6-glucosidase.

Additional properties of amylo-i,6-glucosidase have been studied using a rapid spectrophotometric assay. The ph optimum is in the region between 7.2 to 7.6. The enzyme is inhibited by p-chloromercuribenzoate and o-iodosobenzoate. The inhibition is reversed by glutathione. No inhibition has been observed with glucose but the “debranched” phosphorylase limit dextrin proved an inhibitor of the competitive type with a KI of 50.5 mg per cent. The variation of Km with pH has been determined and indicates that an ionizable enzymic group with a pKa of 7.5–7.6 is involved in combining with substrate. No evidence for significant reversibility of the reaction could be found under the conditions tested.
Instability of a viscous liquid jet surrounded by a viscous gas in a vertical pipe

The instability of a cylindrical liquid jet encapsulated by a viscous gas in a pipe is analysed in a parameter space spanned by the Reynolds number, the Froude number, the Weber number, the density ratio, the viscosity ratio, and the diameter ratio. A convergent solution of the problem is constructed by a Galerkin projection with two orthogonal sets of functions. Two distinctively different modes of instability are obtained. The first is the Rayleigh mode which tends to break up the jet into drops of diameter comparable with the jet diameter. The amplification rate of the disturbance belonging to this mode depends weakly on all parameters except the Weber number which represents the ratio of the surface tension force to the inertia force at the interface. The mechanism of the instability remains that of capillary pinching even in the presence of a viscous gas and gravity. However, the surface tension is stabilizing in the other mode termed the Taylor mode. The Taylor mode instability is due to the pressure and shear fluctuations at the interface. This mode tends to produce droplets of diameters much smaller than that of the jet. It is shown that the former mode appears when the Weber number is much larger than the gas to liquid density ratio. When this ratio is of order one, the instability can be due to either modes depending on the values of the rest of the parameters. When the density ratio is much larger than the Weber number, Taylor's atomization mode replaces the Rayleigh mode.
The measles virus phosphoprotein interacts with the linker domain of STAT1

The measles virus (MV) phosphoprotein (P) and V proteins block the interferon (IFN) response by impeding phosphorylation of the signal transducer and activator of transcription 1 (STAT1) by the Janus kinase 1 (JAK1). We characterized how STAT1 mutants interact with P and JAK1 phosphorylation. Certain mutants of the linker, the Src-homology 2 domain (SH2), or the transactivation domain had reduced or abolished phosphorylation through JAK1 after IFN treatment. Other mutants, mainly localized in the linker, failed to interact with P as documented by the lack of interference with nuclear translocation. Thus the functional footprint of P on STAT1 localizes mainly to the linker domain; there is also some overlap with the STAT1 phosphorylation functional footprint on the SH2 domain. Based on these observations, we discuss how the MV-P might operate to inhibit the JAK/STAT pathway.
Quantitative relations between visual search speed and target-distractor similarity.

Three pigeons worked on visual search tasks in which arrays of 32 small forms appeared in computer-driven displays. Their task was to peck at a unique target among identical distractors; the main dependent variable was the speed with which this target was found. The target and distractor forms for each trial were chosen from a set of forms (usually 16); in most experiments, all possible pairs of forms appeared in each experimental session. Six experiments were run; each yielded a matrix of mean reaction times (RTs), one for each of the form pairs. Such matrices were subject to multidimensional scaling, from which best-fitting interform distances were determined. In four experiments with disparate form sets, Euclidean distance between pairs of forms in multidimensional space was found to approximate an exponential decay function of RT-K, whereK was a constant set for each subject. Two additional experiments showed that RT distributions for single-form pairs were well fit by the convolution of a fixed distribution, approximately Gaussian, and an exponential distribution whose decay parameter varied with interform similarity. The exponential decay parameter may be taken to reflect momentary detection probability, and interform distance in multidimensional space may be taken to measure similarity. Thus, the data as a whole suggest an exponential relation between the probability of detecting a target and the similarity of that target to its surrounding distractors. This relationship is analogous to Shepard’s law of generalization, which states an exponential relation between response probability and similarity.
Ambivalence in modeling oblique saccades

Human oblique saccades might be made by synchronized but independent vertical and horizontal pulse generators; we call this the Cartesian theory. Another hypothesis is that the oblique amplitude and angle are coded centrally and trigonometricallyderived signals are sent to the horizontal and vertical muscles (the polar coordinate theory). We took a Cartesian model and cross-coupled the two generators to produce saccades identical to those of a polar coordinate model. This is disproof by counterexample: the experimental evidence claimed to support the polar coordinate model does not necessarily do so. Moreover, the behavior reported for oblique saccades is so variable, contradictory, idiosyncratic, and species-dependent that any model of the central organization of oblique saccades is probably premature.
The removal of mercury(II) from dilute aqueous solution by activated carbon

Abstract The results of preliminary screening tests comparing the total Hg(II) removal capacity of 11 different brands of commercial activated carbon indicated that a very high percent (99–100%) total Hg removal was attained by all types of activated carbon especially at pH 4–5; the percent total Hg(II) removal decreased with pH's ≷4–5 except activated carbons Nuchar SA and SN which maintained a relatively high percent (>90%) total Hg(II) removal capacity at all pH values. Experiments were then conducted to reveal the mechanisms of Hg(II) removal by Nuchar SA (a powdered carbon). The results show that total Hg(II) removal was brought by two mechanisms: the adsorption and reduction. In order to investigate the kinetics of these two reactions, volatilization by bubbling N2 gas at high flow rate was used to remove the Hg(g) product of the reduction reaction. It was noted that both the adsorption and the reduction/volatilization reactions were highly pH-dependent; at pH approx. approx. 9–10 the extent of reduction/volatilization reaction superceded the adsorption reaction; whereas in the mid-pH region adsorption reaction dominated the total Hg(II) removal. The rate of adsorption reaction is very fast, reaching equilibrium in a few minutes; the rate of reduction/volatilization follows a linear √t expression. The reduction reaction is more significant with Filtrasorb 400 (H-type carbon) than Nuchar SA (L-type carbon). In the presence of strong chelating agent, ethylenediaminetetraacetate (EDTA), the total Hg(II) removal decreases due partly to the formation of less adsorbably mercuric(II)-EDTA complexes.
Effects of x-rays on optical materials and coatings

Analyses of optical components consisting of a metal reflecting layer, a beryllium energy-sharing layer, and a fused silica substrate were done using LXRT, Livermore's version of the XRT (X-Ray Transport) computer code. These are compared with calculations for components lacking the beryllium layer. Our analyses show that the addition of the beryllium significantly hardens the system against x-rays. The mechanisms for this increased hardness are apparent from time-dependent tem-perature and enthalpy plots presented here.
Bloodstream infections in hospitalized adults with sickle cell disease: A retrospective analysis

Bloodstream infections (BSI) are a common cause of morbidity and mortality in people with sickle cell disease (SCD). In children with SCD, BSI are most often caused by encapsulated organisms. There is a surprising paucity of medical literature that is focused on evaluating SCD adults with BSI. We reviewed the charts of adults with SCD and BSI who were admitted to our hospital between April 1999 and August 2003. During this period a total of 1,692 hospital admissions for 193 adults with SCD were identified and 28% of these patients had at least 1 episode of positive blood cultures, with 69 episodes (17%) considered true BSI. Nosocomial BSI occurred in 34 episodes (49%). Among community BSI, in contrast to BSI in children with SCD, Streptococcus pneumoniae was rarely encountered. A high incidence of staphylococcal BSI in adults with SCD was noted. Twenty-eight percent of all BSI were caused by Staphylococcus aureus, and 15 of 22 isolates (68%) of these were methicillin-resistant. Gram-negative organisms, anaerobes, and yeast were found in 21 (27%), 3 (4%), and 4 isolates (5%) of BSI, respectively. Since over 80% of BSI were considered catheter-related, the higher incidence of gram-positive bacterial infections was likely due to the presence of indwelling central venous catheters. Empiric therapy for adults with SCD suspected of having BSI, especially in the presence of indwelling central venous catheters, should include antimicrobial therapy targeted at gram-positive bacteria (especially MRSA) and gram-negative bacteria. Also, if patients are critically ill, consideration should be made to include antifungal agents. Additional research into the adult SCD population appears necessary to further define this problem.
G. N. Lewis's Views on Bond Theory 1900–16

In a recent paper on the origin of G. N. Lewis's concept of the shared electron pair bond, I argued that the sources of Lewis's novel conception were certain ideas of J. J. Thomson and Alfred Parson. Yet the only influence that Lewis explicitly acknowledged was neither of these, but Alfred Werner's. The following statement appears in his book, Valence (1923):I still have poignant remembrance of the distress which I and many others suffered some thirty years ago in a class in elementary chemistry, where we were obliged to memorize structural formulae of a great number of inorganic compounds. Even such substances as the ferricyanides and ferryocyanides were forced into the system, and bonds were drawn between the several atoms to comply with certain artificial rules, regardless of all chemical evidence. Such formulae are now believed to be almost, if not entirely devoid of scientific significance. Such abuse of the structural formula inevitably led to a reaction which found its best expression in the publications of Werner. His Neuere Anschauungen … (1905) marked a new epoch in chemistry; and in attempting to clarify the fundamental ideas of valence, there is no work to which I feel so much personal indebtedness as to this of Werner's.
Cadmium coordination to the zinc binding domains of the non-classical zinc finger protein Tristetraprolin affects RNA binding selectivity.

Abstract Tristetraprolin [(TTP), also known as NUP475 and TIS11] is a non-classical zinc finger protein that regulates inflammatory response via a protein-RNA interaction. Specifically, TTP recognizes AU-rich RNA sequences located on the 3′ untranslated region of messenger RNA associated with cytokines. Recently, TTP was shown to be upregulated when cells were exposed to cadmium. Other types of zinc finger proteins have been shown to bind Cd(II), thus the Cd(II) binding properties of TTP were pursued. Metal binding titrations using Co(II) as a spectroscopic probe for Cd(II) were performed. Cd(II) was found to coordinate to the two Cys 3 His structural zinc sites of TTP (TTP-2D) with an upper-limit dissociation constant, K d , of 3.5 ± 0.1 nM. Upon reconstitution of TTP-2D with Cd(II), the protein recognized target RNA, UUUAUUUAUUU, with a dissociation constant, K d , of 2.4 ± 0.2 nM. The Cd(II)TTP-2D/RNA binding event was more sensitive to base mutations than the Zn(II)TTP-2D/RNA binding event. A single base mutation within the UUUAUUUAUUU oligomer decreased the Cd(II)TTP-2D binding affinity 50-fold and a double mutation decreased the affinity 1000–2000 fold. In comparison, only 2-fold and 15–25 fold changes for Zn(II)TTP-2D binding to the identical RNA sequences are measured.
Quantum mechanics/molecular mechanics methodology for metals based on orbital-free density functional theory

We present a quantum mechanics (QM)/molecular mechanics (MM) formalism for coupling density functional theory (DFT) based quantum simulations to classical atomistic simulations for metals. The multiscale methodology is applicable to systems where important quantum phenomena are confined to a small region, but their impacts could be felt over much larger scales. The concurrent coupling between QM and MM regions is treated quantum mechanically via the orbital-free density functional theory (OFDFT). We propose two energetic formulations for the QM region: one is based on OFDFT and the other based on the Kohn-Sham (KS) DFT. In the first case, the degree of freedom is the electron charge density in the QM region, and the total energy functional is directly minimized with respect to the charge density. In the second case, the degrees of freedom are KS orbitals in the QM region. An embedding potential representing the influence of the larger MM region onto the QM region is included in the KS Hamiltonian for the QM region, which is solved self-consistently. Calculations for a perfect lattice and vacancy clusters of aluminum demonstrate that the present QM/MM approaches yield excellent results both in terms of energetics and electron density.
Evidence for Activated Carrier Mobility in Organic Solids

STEADY state space charge limited currents (SCLC) were obtained at different temperatures for a series of dipyridy-lium model compounds (Fig. 1) into which one TCNQ molecule (tetracyanoquinodimethane), in the form of a radical ion, was introduced. Some compounds were produced containing two molecules of TCNQ, one associated with each ring. Polymers of these compounds were also produced and SCLC measured (details of preparation will be published elsewhere).
Using artificial intelligence for CyanoHAB niche modeling: discovery and visualization of Microcystis–environmental associations within western Lake Erie

Cyanobacterial harmful algal blooms (CyanoHABs), mainly composed of the genus Microcystis, occur frequently throughout the Laurentian Great Lakes. We used artificial neural networks (ANNs) involvin...
Does Treatment of Asymptomatic, Small Renal Calculi Depend on the Patient Population?

“DR. Monga doesn’t let me come up with a plan for the patient,” my residents tell me on my faculty evaluation. That’s the whole point. Shared decision making involves providing the patient and family the information needed to make an informed decision. In this issue of The Journal Dropkin et al (page 1265) provide this information for patients with asymptomatic renal calculi. 1 Patients who elected to watch their calculi were followed every 6 months with renal ultrasound. Prior studies have suggested that for medium size asymptomatic renal stones, only 23% of patients would elect observation. 2 As such, this is a select group and a certain amount of selection bias may weigh into the observations and conclusions. At 3.5-year followup 28% of patients experienced symptoms. Upper and middle calyceal stones were more likely to pass (14%) or cause symptoms (41%) than lower calyceal stones. Overall 28% of patients underwent surgery. These observations are similar to a series reported 10 years ago. The current study did not demonstrate that lower pole stones were more likely to grow or that outcomes were tied to the initial stone size, although this may be related to a smaller sample size. Prior studies have followed patients with annual radiographic followup. It may be helpful for the authors to evaluate the impact of 6-month followup. Would any adverse events have occurred if the followup had been streamlined to annual imaging? The finding that painless silent hydronephrosis developed in 2% of patients raises an important concern, and indeed makes a case for elective treatment of stones 5 to 10 mm in size. “Doctor e what would you do if it were you?” When engaged in shared decision making, the majority of patients seek the doctor’s recommendation. 3 If greater than 5 mm, fire up the treatment head and raise the plenum!
Vanadyl(IV) conalbumin. I. Metal binding site configurations

Electron paramagnetic resonance (epr) and ultraviolet difference spectroscopy of vanadyl conalbumin indicate a binding capacity of two vanadyl ions, VO2+, per protein molecule in the pH 8–11 range; the binding capacity drops in the pH 6–8 range with an apparent pKa′ = 6.6. Iron-saturated conalbumin does not bind vanadyl ions, which suggests common binding sites for iron and vanadium. Ultraviolet difference spectroscopy indicates 2–3 tyrosines are involved in the binding of each metal ion; pH titrations show that three protons are released per vanadyl ion bound by conalbumin. Room and liquid nitrogen temperature X-band (ca. 9.2–9.5 gHz) epr spectra show that the vanadyl ion binds in three magnetically distinct environments (A, B, and C) that arise from interconvertible metal site configurations. These configurations are probably examples of conformational substrates of the protein. Q-band (ca 34 gHz) epr spectra resolve the spectral features more clearly and show that two configurations (A and B) have axially symmetric epr parameters but angles of noncoincidence of 12° and 8°, respectively, between the z components of the g and nuclear hyperfine tensors. The third (C) configuration has rhombic magnetic symmetry and a 6° angle of noncoincidence. These observations demonstrate that the metal sites are of low symmetry and are flexible in their geometry about the metal. The isotropic g and nuclear hyperfine tensor values and the line widths used in computer-simulated epr spectra are consistent with four oxygen or three oxygen and one nitrogen donor atoms binding equatorially to the VO2+ group. The apparent stability constant indicates that vanadyl ion binds to conalbumin approximately twelve orders of magnitude more weakly than iron to human serotransferrin but still sufficiently strongly to overcome hydrolysis.
Estimating Persistence Length of DNA from Molecular Dynamics Simulations

Bending rigidity of DNA is one of its most important mechanical properties, since in eukaryotic cells a vast majority of the DNA (75-80%) is tightly packed into chromatin. Classical experiments have measured the persistence length (PL) of DNA, which is directly related to its bending rigidity, to be about 45-50 nm (140-160 bp). Previous all-atom molecular dynamics (MD) studies of DNA flexibility attempted to calculate this value using relatively small fragments (much less than PL) in explicit solvent. However, the simulations are usually computationally expensive due to a large number of water molecules required to construct the solvent box, and the resulting PL approximations are greater than the experimental values. One possible explanation for this discrepancy between experiment and simulation may be that classical experimental measurements were performed with DNA fragments on the order of PL or greater, while fragments much smaller than PL have so far been used in MD studies. In this work we provide a computationally inexpensive method of estimating the PL of DNA from atomistic MD simulations of long fragments on the order of PL (∼150 bp) in implicit solvent that provides good agreement with experiment.
When scientists politicize science: making sense of controversy over The Skeptical Environmentalist

Scholars of science and society have long understood that in all but the most trivial of cases science cannot compel specific political outcomes. Rather, scientific understandings are frequently either intrinsically uncertain or diverse enough to be used to justify a range of competing political agendas. This paper argues that despite these understandings the use of science by scientists as a means of negotiating for desired political outcomes – the politicization of science by scientists – threatens the development of effective policies in contested issues. By tying themselves to politics, rather than policy, scientists necessarily restrict their value and the value of their science. The essay proceeds in four parts. It first discusses why the politicization of science by scientists might be worth our concern. Second, it reviews the debate over the publication of The Skeptical Environmentalist . Third, it suggests that arguments that embraces a “linear model” (i.e., get the facts right, then act) of science’s relationship with policy encourage the politicization of science. The fourth section discusses a range of perspectives on the politicization of science by scientists, and the paper concludes with a discussion of an alternative way to think about the relationship between science, politics and policy. © 2004 Elsevier Ltd. All rights reserved.
CAD, a c-Myc target gene, is not deregulated in Burkitt's lymphoma cell lines.

Although the Myc family of transcription factors is upregulated in many human tumors, it is unclear which genes are targets for the deregulated Myc. Previous studies suggest that hamster and rat carbamoyl phosphate synthase, aspartate transcarbamylase, dihydroorotase Cad genes are regulated by c-Myc. In fact, of all putative target genes thought to be activated by c-Myc, only the Cad gene showed loss of growth regulation in rat cells nullizygous for c-Myc. However, it was unknown whether upregulation of CAD, which performs the first three rate-limiting steps of pyrimidine biosynthesis, contributes to c-Myc's role in human neoplasia. To explore this possibility, we cloned the human cad promoter. We found that c-Myc could bind to an E box in the human cad promoter in gel shift assays and that growth regulated transcription from the human cad promoter was dependent on this c-Myc binding site. However, the increased amount of c-Myc found in Burkitt's lymphoma cell lines did not lead to increased cad mRNA levels. Thus, we suggest that although c-Myc is clearly important for the normal transcriptional control of the cad promoter, it is unlikely that increased levels of CAD are important mediators of c-Myc-induced neoplasia. Therefore, an understanding of the mechanism by which overexpressed c-Myc contributes to the development of Burkitt's lymphoma requires the identification of additional c-Myc target genes.
Mixing effects on performance and stability of low-density polyethylene reactors

Imperfect initiator mixing greatly affects the stability and efficiency of low density polyethylene (LDPE) autoclave reactors. A combined simulation technique utilizing compartment models and computational fluid dynamics extends previous work in the literature by providing a physically detailed picture of imperfect mixing. Analysis indicates that the effective volume for chain propagation in the autoclave reactor can expand and contract in a continuous fashion as operating conditions change. As mixing becomes poor, the effective reactive volume decreases, causing a reduction in initiator efficiency, but an expansion in the stable operation region. Examples demonstrate that accurate prediction of the effective reaction volume is crucial for predicting LDPE autoclave reactor behavior. A new mixing model that represents the feed plume by a series of interconnected tanks with geometrically increasing volumes provides a favorable tradeoff between accuracy and model complexity. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Reply to the note by Neuman 'Is fertility indeed related to religiosity?'

Neuman uses the rich information on religion contained in the International Social Survey Programme 1998: Religion II (ISSP 98) to estimate fertility equations similar to those in my paper. She concludes that current religiosity is not related to the number of children a woman has and that my findings are due to a misspecification of the religiosity measure. In this reply I argue that her results rely on the use of a group of women already selected for their attachment to the Catholic Church. I include new analyses with the ISSP 98 data-set to show that the positive relation between attendance at mass and fertility holds in a sample that includes those who have ever been baptized regardless of the background of their spouses. Further I explore an alternative measure of religiosity in the ISSP 98. Finally I make some clarifications of the findings in the paper and their relevance to the explanation of recent fertility changes in Spain. (excerpt)
Operation of transferred-electron oscillators in the ridge-waveguide circuit

Operation of high-power X and K. band transferred-electron oscillators (t.e.o.s) in waveguide circuits is described. An increase in c.w. efficiency from 2.5 to 3.5% by decreasing the impedance of the waveguide circuit is reported. Output powers as high as 1.0 W at 10 GHz with 2.5% efficiency and 500 mW at 20 GHz with 3% efficiency were obtained in a ridge-waveguide circuit.
Inhibition of Cholinergic Signaling Causes Apoptosis in Human Bronchioalveolar Carcinoma

Recent case-controlled clinical studies show that bronchioalveolar carcinomas (BAC) are correlated with smoking. Nicotine, the addictive component of cigarettes, accelerates cell proliferation through nicotinic acetylcholine receptors (nAChR). In this study, we show that human BACs produce acetylcholine (ACh) and contain several cholinergic factors including acetylcholinesterase (AChE), choline acetyltransferase (ChAT), choline transporter 1 (CHT1, SLC5A7), vesicular acetylcholine transporter (VAChT, SLC18A3), and nACh receptors (AChRs, CHRNAs). Nicotine increased the production of ACh in human BACs, and ACh acts as a growth factor for these cells. Nicotine-induced ACh production was mediated by α7-, α3β2-, and β3-nAChRs, ChAT and VAChT pathways. We observed that nicotine upregulated ChAT and VAChT. Therefore, we conjectured that VAChT antagonists, such as vesamicol, may suppress the growth of human BACs. Vesamicol induced potent apoptosis of human BACs in cell culture and nude mice models. Vesamicol did not have any effect on EGF or insulin-like growth factor-II-induced growth of human BACs. siRNA-mediated attenuation of VAChT reversed the apoptotic activity of vesamicol. We also observed that vesamicol inhibited Akt phosphorylation during cell death and that overexpression of constitutively active Akt reversed the apoptotic activity of vesamicol. Taken together, our results suggested that disruption of nicotine-induced cholinergic signaling by agents such as vesamicol may have applications in BAC therapy.
A simple yet effective merging scheme for prescribed-skew clock routing

In order to achieve multi-GHz operation frequency for VLSI design, clock networks need to be designed in a very elaborated manner and be able to deliver prescribed useful skews rather than merely zero-skew. Although traditional zero-skew clock muting methods can be extended directly to prescribed skews, they tend to result in excessive wirelength as the differences among delay-targets for clock sinks are neglected. In this paper, we propose the maximum delay-target and minimum merging-cost merging scheme for prescribed-skew clock routing. This scheme is simple yet surprisingly effective on wirelength reduction. Experimental results on benchmark circuits show that our merging scheme yields 53%-61% wirelength reduction compared to traditional clock routing methods.
Silylation of Non-Terminal Double Bonds of Natural Oils

Silylation of non-terminal double bonds of unsaturated fatty acids with reactive organosilicons was successfully accomplished using the ‘Ene’ reaction route. The ‘Ene’ reaction, which is a subset of the famous Diels Alder reaction, enables grafting of vinyl silanes onto unsaturated organic molecules irrespective of the position of the double bond. This procedure was used to graft vinyltrialkoxysilanes onto unsaturated fatty acids of various triglyceride oils. Methyl oleate and methyl stearate were used as model compounds to investigate this reaction. 1H NMR and TGA were used to characterize the structure of the silylation products and to determine the extent of grafting as a function of reaction conditions. It was found that this grafting reaction follows a second order kinetics. Under extreme conditions a silyl-ester redistribution reaction can also occur where an alkoxy group attached to the silicon atom is exchanged with an alkoxy group of the organic ester. Grafting vinyltrimethoxysilane onto natural oils such as soybean, canola and Abyssinian oils leads to a convenient one-component, moisture activated cure system of these natural oils.
Prevention of postoperative nausea and vomiting in children following adenotonsillectomy, using tropisetron with or without low-dose dexamethasone

Purpose Postoperative nausea and vomiting (PONV) after adenotonsillectomy in children is, in spite of the prophylactic administration of tropisetron, still a frequent event. The aim of this study was to evaluate the benefit of the additional systemic administration of low-dose dexamethasone (0.15 mg·kg−1) for the prevention of PONV.
Exploring estuarine eutrophication sensitivity to nutrient loading

The sensitivity of surface chlorophyll (Chl) and bottom water dissolved oxygen (DO) to total nitrogen (TN) load was investigated using a Bayesian-based process model fit to data from a range of estuaries. The model was used to test if the sensitivity of DO depletion to TN loads is dependent only on factors controlling the sensitivity of surface Chl, or if additional factors are important. Results indicate that separate processes control Chl and DO sensitivity, and that these sensitivities vary among estuaries. Analysis of fitted parameters across estuaries showed that Chl sensitivity to TN loading was positively correlated with water residence time, and DO sensitivity to Chl was positively correlated with relative mixing depth.
The effect of a narrowband interference rejection filter on coarse acquisition in direct sequence spread spectrum

The performance of a direct sequence spread spectrum system using a linear prediction filter for interference suppression is given when narrowband Gaussian interference is present at the input. The performance of this system is compared to that of a similar acquisition system using transform domain processing techniques to implement a notch filter. When the interference bandwidth is small, the linear prediction filtering technique is shown to be superior, providing good performance over a wide range of the ratio of interference-power-to-signal-power (J/S). At larger interference bandwidths, it is shown that the transform domain processing technique is better than the linear prediction technique, but good performance levels can only be achieved over a limited range of J/S. Both the linear prediction filter (LPF) and transform domain processing (TDP) based acquisition systems, and the nature of the input signal, are described. >
Simple and efficient synthesis of 5′ pre-adenylated DNA using thermostable RNA ligase

We report a simple method of enzymatic synthesis of pre-adenylated DNA linkers/adapters for next-generation sequencing using thermostable RNA ligase from Methanobacterium thermoautotrophicum (MthRnl). Using RNA ligase for the reaction instead of the existing chemical or T4 DNA ligase-based methods allows quantitative conversion of 5′-phosphorylated single-stranded DNA (ssDNA) to the adenylated form. The MthRnl adenylation reaction is specific for ATP and either ssDNA or RNA. In the presence of Mg+2, the reaction has a pH optimum of 6.0–6.5. Unlike reactions that use T4 DNA ligase, this protocol does not require synthesis of a template strand for adenylation. The high yield of the reaction simplifies isolation and purification of the adenylated product. Conducting the adenylation reaction at the elevated temperature (65°C) reduces structural constraints, while increased ATP concentrations allow quantitative adenylation of DNA with a 3′-unprotected end.
Effects of different ocular fixation conditions on A-scan ultrasound biometry measurements.

A-scan readings must he taken along the visual axis for accurate axial length measurement. Various fixation targets, which ideally should not induce accommodation, are used to limit eye movements. In this study results using the Humphrey biometer under different fixation conditions were compared to establish the most suitable target. We also investigated corneal applanation effects by comparing optical and ultrasonic measurements of anterior chamber depth. We examined 12 randomly selected normal eyes of 12 young subjects. Three A-scans were recorded for each of five fixation conditions: spotlight at 6 m: Snellen letter at 6 m; solid probe's built-in green fixation target; Snellen letter at 6m viewed through a –4.00 DS lens: spotlight at d m under cycloplegia (the comparison condition I. Variability ‘within’ each fixation condition. estimated by the standard deviation for each subject, was equal throughout the 12 subjects for each fixation condition. Also variation was independent of size of the ocular dimension. The good agreement between the comparison condition and optical anterior chamber depth measurements indicated that the solid probe produced little applanation. Differences ‘between’ fixation conditions were investigated. It was concluded that a spotlight or letter at 6 m provides a suitable fixation target for biometry. Built-in fixation targets can produce significant errors.
First demonstration of an As 2 S 3 -on-LiNbO 3 ring resonator

A race-track ring resonator with a 600µm diameter and 25GHz free spectral range is demonstrated by vertically integrating arsenic-trisulfide (As 2 S 3 ) waveguides with Ti-diffused LiNbO 3 waveguides. Measurements of the TM ring resonator response are presented.
Developing Self-Directed Executive Functioning: Recent Findings and Future Directions

How do children become increasingly self-directed across development, achieving their goals without help from others? How might such developments be impacted by societal changes in how children spend their time? Children's abilities to achieve their goals are supported by developing executive functions (EFs), cognitive processes that predict important life outcomes. Efforts to improve children's EFs have benefitted their externally driven executive functioning, where goals and instructions are provided by others. Less is known about self-directed EF, when children must decide independently what to do and when. We present recent findings demonstrating that children are better at engaging self-directed EF when they have good understanding of options to choose among, and if they spend time in activities that they play a large role in directing. Within this context, we discuss the potential role of opportunities to plan, mind-wander, and play, and present the critical next steps in investigating the influence of changing environments on self-directed EF.
GaAs optoelectronic smart pixel arrays

In summary, our long term directions will involve the monolithic integration of vertical cavity surface emitting lasers (VCSELs), either p-i-n or photoconducting detectors, and the complementary heterostructure field effect transistor LC technology. An approach to the monolithic integration of these structures is illustrated. >
An ovomucin-like protein on the surface of migrating primordial germ cells of the chick and rat

A mucin was discovered on the surface of migratory primordial germ cells (PGCs) from chick and rat embryos by means of two monoclonal antibodies. The protein was found to be identical or closely related to ovomucin, a 600 X 10(3) relative molecular mass glycoprotein, and a major constituent of the vitelline membrane of the avian yolk. Based on its resemblance to ovomucin it is referred to as ovomucin-like protein (OLP). The OLP was expressed on PGCs from E3 to E7 female, and from E3 to E12 male chick embryos as the PGCs migrate and colonize the gonadal ridges. After the PGCs have settled in the gonads, they no longer express OLP. In tissue cultures of dissociated cells from E6 gonads, OLP was present only on cells that were positive for PAS staining, the standard histological method to identify PGCs in the chick embryo. Since unfixed PGCs were recognized by the antibodies, at least part of the OLP is localized on the cell surface. The anti-OLP antibodies also stained PGCs in the gonads of the rat embryo, showing that the expression of this antigen on PGCs is phylogenetically conserved. Ovomucin isolated from vitelline membrane prevented adhesion of fibroblasts but not PGCs when used a as a substratum in vitro. The anti-adhesive quality of the mucin resides in the sialic acid residues of the carbohydrate side chains. We propose that OLP has a similar anti-adhesive quality as the ovomucin from vitelline membrane, and that this anti-adhesive property is important to prevent precocious adhesion of migrating PGCs to blood vessel walls and to connective tissue in the mesentery as they migrate toward the gonadal ridges.
Structure and composition of the postsynaptic density during development.

In this study, we used electron tomography as well as immunogold labeling to analyze the morphology and distribution of proteins within postsynaptic densities (PSDs) isolated from rats before birth (embryonic day 19) and at postnatal days 2, 21, and 60. Our data provide direct evidence of distinct morphological and compositional differences in PSDs throughout development. Not all PSD components are present at the early stages of development, with a near lack of the scaffolding molecule PSD-95 at E19 and P2. The presence of NR1 and NR2b suggests that PSD-95 is not directly required for clustering of N-methyl-D-aspartic acid (NMDA) receptors in PSDs early in development. α-Actinin is abundant by E19, suggesting that it is a core structural component of the PSD. Both α and β isoforms of Ca2+/calmodulin-dependent protein kinase II (CaMKII) are present early on but then rise in labeling density by approximately fourfold by P21. Among all the molecules studied, only calmodulin (CaM) was found in higher abundance early in PSD development and then fell in amount over time. Spatial analysis of the immunogold label shows a nonrandom distribution for all the proteins studied, lending support to the idea that the PSD is systematically assembled in an organized fashion. Morphological data from electron tomography shows that the PSD undergoes major structural changes throughout development. J. Comp. Neurol. 518:4243–4260, 2010. © 2010 Wiley-Liss, Inc.
TO VIEW OR NOT TO VIEW: Examining the Plain View Doctrine and Digital Evidence

The very nature of digital evidence, defined as evidence stored on any form of magnetic media, makes the proper collection of such evidence an important consideration during seizure. Historically, courts have attempted to apply jurisprudence developed for the physical world to cases involving the cyber world. As a result, confusing guidelines have been created for those who handle computerrelated investigations. This article examined the issue of warrantless searches and seizures of digital evidence justified under the plain view doctrine. Through examination of the Fifth Circuit decision, United States v. Carey (1999), and the Virginia district court decision, United States v. Gray (1999), it was determined that proper seizure of digital evidence under the plain view doctrine requires: 1) access to the evidence be obtained legally, 2) the apparent illegal nature of the evidence be immediately known, and 3) the officer cannot abandon their original search.
Better Understanding of Severe Immunological Reactions: Autoimmune Diseases

Autoimmune diseases, which result from an imbalance between activated immune responses mediated by antibodies or cytotoxic T cells, and immunosuppressive reactions mediated by various factors including regulatory T cells, are one of the major causes of morbidity and mortality worldwide. This chapter summarizes the current status of autoimmune disease research from the aspect of immunogenetic/immunogenomic pathogenesis. Findings from association studies, including genome-wide association studies (GWASs), could contribute to further understanding of the etiology of autoimmune diseases. For example, certain types of HLA class II molecules have been identified to have possible roles in the pathogenesis of autoimmune diseases. Recent studies have implied the usefulness of deep T-cell repertoire analysis in individual patients for identification of self-antigens, which are presented on HLA molecules involved in the development and progression of autoimmune diseases. We believe it is timely to review progress in current knowledge of autoimmune disease biology, as well as future prospects for autoimmune disease research through the immunopharmacogenomics approach.