cssi/SciSciGPT-SciSciNet huggingface dataset:
The interaction of paramagnetic ions chelated to ATP with pyridoxal analogues. Fluorescence studies of pyridoxal kinase.

Fluorescence spectroscopy, static and dynamic, was applied to deduce proximity relationships between paramagnetic metal ions chelated to ATP and the inhibitor pyridoxal oxime bound to the site of the substrate pyridoxal. The fluorescence yield of free pyridoxal oxime is considerably reduced in the presence of CoCl2 (1 mM) due to the formation of a non-fluorescent complex. The fluorescence properties of pyridoxal oxime bound to pyridoxal kinase (50 μM, Kd= 1 μM) remain invariant in the presence of CoCl2 (1 mM) and ATP (1 mM). The results are interpreted to mean that the distances are too great for direct or first-coordination-sphere interaction between pyridoxaloxime and Co(II) centers. The bidentate complex Cr(III) · ATP is a competitive inhibitor of ATP (Ki= 83 μM) and its binding to pyridoxal kinase (50 μM) complexed to pyridoxal oxime (50 μM) was monitored by static and dynamic fluorescence spectroscopy. The fluorescence yield of bound pyridoxal oxime is reduced by 25% in the presence of Cr(III) · ATP (0.8 mM) leading to a decrease in fluorescence lifetime from 〈τ〉= 6.60 ns to 〈τ〉= 4.20 ns. The decrease in fluorescence yield together with a diminution in fluorescence lifetime can be explained in terms of radiationless energy transfer from excited pyridoxal oxime to Cr(III) chelated to ATP. Using Forster's equation and an efficiency of energy transfer of 0.25, it was found that a distance of 1.3 nm separates pyridoxal oxime from the Cr(III) center.
A COMPARISON OF SYNTAX TRAINING FOR STUDENTS WITH DEVELOPMENTAL DISABILITIES UTILIZING CLINICIAN-DIRECTED VERSUS SELF-DETERMINED SESSION PARADIGMS

Self-determination is the ability to control one’s life and to actively participate in the decisions which affect the direction of one’s life. This ability is considered a critical life skill for individuals with developmental disabilities. The ability to make choices, plan, and self-evaluate are among the primary skills included in the development of self-determination. Currently, there is very limited emphasis on the importance of self-determination in the literature of communication disorders. This study was designed to determine if a teaching paradigm which incorporates key elements of self-determination is as or more effective and efficient in teaching syntax than a traditional, clinician-directed teaching paradigm for students with developmental disabilities. Two methods of syntax instruction were compared for 4 students with Down syndrome between the ages of 7 and 13 years using an Adapted Alternating Treatment (AAT) single subject design. In the Clinician Directed (CD) condition, the clinician selected the reinforcing activities, scheduled the order of those activities, and provided the students with feed-back on the accuracy of their productions. In the Self-Determined (SD) condition, the students chose the reinforcing activities from 4 possible choices, scheduled the order of activities, and self-evaluated the accuracy of their productions. Results of the study indicated that both the traditional clinician-directed approach (CD)and the self-determined approach (SD) were effective in teaching syntax targets with all 4 students achieving criterion at an unexpectedly rapid rate and maintaining skills regardless of the teaching condition. The CD condition was slightly more efficient than the SD condition in achieving criterion for 3 of the 4 students in the study; however, for 2 of these 3 students, there was a difference of only 1 session between the 2 conditions. In the SD condition the students were required to self-evaluate responses, a key element in the development of self-determination skills. Interestingly, students appeared to learn to self-correct errors slightly sooner in the SD than the CD condition. Further investigation is needed, but a case might be made that including elements of self-determination in syntax training could justify the slight loss of efficiency, and does so without disrupting teaching effectiveness.
The Binding of Desialylated Glycoproteins by Plasma Membranes of Rat Liver

Abstract Evidence is presented to identify plasma membranes of liver as the major locus of binding for circulating glycoproteins. The binding process involves a dual role for sialic acid in that its presence on the membranes is essential, whereas its presence on the glycoprotein is incompatible with binding. Enzymatic restoration of sialic acid residues onto partially desialylated membranes is accompanied by increased binding activity and is suggestive of the presence of an intrinsic membrane-associated sialyltransferase. In addition to the requirement for sialic acid, the binding of proteins by plasma membranes exhibits an absolute dependence upon the presence of calcium. Changes in the concentration of this ion, within the pH range of 6.0 to 7.8, result in a rapid reversal of the binding process and provide a model system for the study of protein uptake and transport by the intact liver cell.
Hemolytic Transfusion Reaction Occurring in a Patient with Acute Renal Failure

An acute hemolytic transfusion reaction due to ABO-incompatibility occurred in a patient during the fifth week of oliguria secondary to post-traumatic acute renal failure. Resort to "plasma-exchange" transfusion to reduce the high level of free hemoglobin in the circulation was considered and rejected. Sequential measurements of free and haptoglobin-bound hemoglobin documented rapid disappearance of both components from the patient’s plasma in the absence of hemoglobinuria. Within one week, the patient entered the diuretic phase, and ultimately stabilized at normal levels of urine volume, with a creatinine clearance of 53 ml per minute. The implications of free hemoglobinemia in the oliguric phase of acute renal failure are discussed.
Quantitative cell lysis of indigenous microorganisms and rapid extraction of microbial DNA from sediment.

This study reports improvements in two of the key steps, lysis of indigenous cells and DNA purification, required for achieving a rapid nonselective protocol for extracting nucleic acids directly from sodium dodecyl sulfate (SDS)-treated sediment rich in organic matter. Incorporation of bead-mill homogenization into the DNA extraction procedure doubled the densitometrically determined DNA yield (11.8 micrograms of DNA.g [dry weight] of sediment-1) relative to incorporation of three cycles of freezing and thawing (5.2 micrograms of DNA.g [dry weight] of sediment-1). The improved DNA extraction efficiency was attributed to increased cell lysis, measured by viable counts of sediment microorganisms which showed that 2 and 8%, respectively, survived the bead-mill homogenization and freeze-thaw procedures. Corresponding measurements of suspensions of viable Bacillus endospores demonstrated that 2 and 94% of the initial number survived. Conventional, laser scanning epifluorescence phase-contrast, and differential interference-contrast microscopy revealed that small coccoid bacterial cells (1.2 to 0.3 micron long) were left intact after combined SDS and bead-mill homogenization of sediment samples. Estimates of the residual fraction of the fluorescently stained cell numbers indicated that 6% (2.2 x 10(8) cells.g [dry weight] of sediment-1) of the original population (3.8 x 10(9) cells.g [dry weight] of sediment-1) remained after treatment with SDS and bead-mill homogenization. Thus, lysis of total cells was less efficient than that of cells which could be cultured. The extracted DNA was used to successfully amplify nahR, the regulatory gene for naphthalene catabolism in Pseudomonas putida G7, by PCR.(ABSTRACT TRUNCATED AT 250 WORDS) Images
Performance of DB2 Enterprise-Extended Edition on NT with Virtual Interface Architecture

DB2 Universal Database Enterprise-Extended Edition (DB2 UDB EEE) is a parallel relational database management system using a shared-nothing architecture. DB2 UDB EEE uses multiple nodes connected by an interconnect and partitions data across these nodes. The communication protocol used between nodes of DB2 UDB EEE has historically been Transmission Control Protocol (TCP) / Internet Protocol (IP) but has now been extended to include the Virtual Interface (VI) Architecture. This paper discusses a new protocol termed Virtual Interface Protocol (VIP), built on top of the primitives provided by the VI Architecture. DB2 UDB EEE with VIP on a fast interconnect has shown significant improvement in reducing the elapsed time of queries when compared with TCP/IP over fast ethernet. This paper discusses the implementation and performance results on a Transaction Processing Council's Decision (TPC-D) support database.
Induction; the Binomial Theorem

The first part of the course deals with the integers ℤ and the natural numbers ℕ. You know how to add and subtract, multiply and divide integers, and you know when one integer is bigger than another; we shall not review these things. One property of the integers which does need review is the principle of induction. It is the basis for most proofs involving natural numbers, for it gives a general procedure for verifying statements about all natural numbers (an infinite set). It comes in various formulations. Here is the first.
Degradation of linear DNA by a strand-specific exonuclease activity in Xenopus laevis oocytes.

Abstract Linear DNA injected into Xenopus laevis oocyte nuclei recombines with high efficiency if homologous sequences are present at overlapping molecular ends. We found that injected linear DNA was degraded by a 5'----3' strand-specific exonuclease activity during incubation in the oocyte nucleus to leave a heterogeneous population of 3'-tailed molecules. Decreasing the concentration of DNA injected increased the heterogeneity and the average rate of degradation. The 3' tails created were relatively stable; among molecules persisting after overnight incubation, many had 3' tails intact to within 10 bases of the original ends. DNA molecules that were efficient substrates for homologous recombination in oocytes were also partially degraded, leaving 3' tails. We found no evidence for other potent nuclease activities. If molecules with recessed 3'-OH ends were injected, endogenous polymerase efficiently resynthesized complementary strands before degradation of the 5' tails occurred. 3'-tailed molecules are plausible intermediates in the initiation of homologous recombination events in Xenopus oocyte nuclei.
A robust and quantitative method for tracking liposome contents after intravenous administration.

We introduce a method for tracking the rate and extent of delivery of liposome contents in vivo based on encapsulation of 4-methylumbelliferyl phosphate (MU-P), a profluorophore of 4-methylumbelliferone (MU). MU-P is rapidly dephosphorylated by endogenous phosphatases in vivo to form MU after leakage from the liposome. The change in fluorescence spectra when MU-P is converted to MU allows for quantification of entrapped (MU-P) and released (MU) liposome contents by fluorescence or by a sensitive high performance liquid chromatography assay. We define the “cellular availability” of an agent encapsulated in a liposome as the ratio of the amount of released agent in the tissue to the total amount of agent in the tissue; this parameter quantifies the fraction of drug available for therapy. The advantage of this method over existing technologies is the ability to decouple the signals of entrapped and released liposome contents. We validate this method by tracking the circulation and tissue distribution of MU-P loaded liposomes after intravenous administration. We use this assay to compare the cellular availability of liposomes composed of engineered phosphocholine lipids with covalently attached cholesterol, sterol-modified lipids (SML), to liposomes composed of conventional phospholipids and cholesterol. The SML liposomes have similar pharmacokinetic and biodistribution patterns as conventional phospholipid–cholesterol liposomes but a slower rate of contents delivery into the tissue. Thus, MU-P enables the tracking of the rate and extent of liposome contents release in tissues and should facilitate a better understanding of the pharmacodynamics of liposome-encapsulated drugs in animals.
Head circumference in the clinical detection of PTEN hamartoma tumor syndrome in a clinic population at high-risk of breast cancer

PTEN Hamartoma Tumor Syndrome (PHTS) is often recognized by the presence of macrocephaly and associated mucocutaneous features, and is notable for a profound predisposition to breast and thyroid cancers. Head circumference (HC) is rarely measured when evaluating women at high risk for breast cancer, but may offer insight into characterizing cancer risk. Patients enrolled in the University of Michigan Cancer Genetics registry for breast cancer evaluation were analyzed for personal and family history of cancer and features of PHTS. This group of women was compared to all women who had undergone PTEN testing and whether or not they met clinical criteria for PHTS. Among the 164 women referred for breast cancer risk evaluation, a statistically significant difference in mean HC was found between women who did (57.3 cm) and did not (55.4 cm) meet clinical criteria for PHTS with both values below the established threshold for macrocephaly (58 cm). The sensitivity and specificity of macrocephaly for the presence of a PTEN mutation were 100 and 53%, respectively, among the 28 women tested. The positive predictive value was 14%. PTEN mutation positive and PTEN mutation negative women were not well differentiated by PHTS clinical criteria (P = 0.2348). The high sensitivity of HC suggests that this simple measure can improve the detection of unrecognized patients with PHTS. Measuring HC is a useful clinical feature, but is insufficient as a singular screening tool for PHTS. Even in a high risk population, the PPV of this test is low. Diagnosis of this important genetic syndrome still relies heavily on detailed history and full physical exam.
Mechanism of oxidation of 1-methyl-4-phenyl-2,3-dihydropyridinium (MPDP+).

Summary Oxidase electrode measurements have shown that the neurotoxin metabolite 1-methyl-4-phenyl-2,3-dihydropyridinium autoxidizes to hydrogen peroxide and 1-methyl-4-phenylpyridinium in a reaction promoted by iron chelates. The mechanism of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity is discussed in the light of these findings.
Achieving enhanced gain in photorefractive polymers by eliminating electron contributions using large bias fields

Photorefractive polymers have been extensively studied for over two decades and have found applications in holographic displays and optical image processing. The complexity of these materials arises from multiple charge contributions, for example, leading to the formation of competing photorefractive gratings. It has been recently shown that in a photorefractive polymer at relatively moderate applied electric fields the primary charge carriers (holes) establish an initial grating, followed by a subsequent competing grating (electrons) resulting in a decreased two-beam coupling and diffraction efficiencies. In this paper, it is shown that with relatively large sustainable bias fields, the two-beam coupling efficiency is enhanced owing to a decreased electron contribution. These results also explain the cause of dielectric breakdown experienced under large bias fields. Our conclusions are supported by self-pumped transient two-beam coupling and photocurrent measurements as a function of applied bias fields at different wavelengths.
Sources and observers in motion, II: Acoustic radiation from a small rigid body in arbitrary motion

The theory in reference [1], for a source in rectilinear motion, using time variant analysis and an invariant surface flux source description, is extended here to include arbitrary source motion. The special case of a small rigid object is considered, with motion in a circle used as a simple example. The effect of convective motion is expressed entirely through changing amplitude and time scales, both of which are given in terms of a single time varying factor.
Phenolic polymer–surface interactions from ab initio computations

Test calculations show that the diamond surface binding energy of C13H11O2, the simplest model for phenolic, is virtually the same as that of C6H5. Using the C6H5 model, we compare the binding to a diamond surface, a graphene sheet, a (10, 0) nanotube, and a silica surface. The binding energy is more than 5 eV for the silica and 2.85 eV for the diamond surface. As expected, the binding energy of a second molecule at a site adjacent to the first molecule is larger than the first binding energy for the graphene sheet and the carbon nanotube, since the first C6H5 bond breaks a π bond and the second molecule bonds to the unpaired π electron created by adding the first molecule. For all of the systems, adding a C2 unit between the surface and the C6H5 group increases the binding by at least 0.51 eV and up to 2.3 eV. Part of this increase is due to the intrinsically stronger bonding for the sp hybridization and part due to a decrease in the surface–C6H5 repulsion.
Performance modeling and optimization of networks of bridged LANs

An internetwork of LANs is modeled as a graph with LAN segments as edges and transparent bridges and repeaters as nodes. The graph model leads to a simple expression for the effective load on an arbitrary LAN segment, which takes into account the overhead traffic due to the learning mechanism of the transparent bridges. Simplifying assumptions for the operation of the MAC layer protocol lead to a simple expression for the average end-to-end delay in terms of the effective loads on the LAN segments.
Results of CD-R media study

CD-R media is increasingly being looked upon as an excellent archival media with an estimated storage life on the order of 100 years. Since the government will be making large investments in CD-R media, it is imperative that the characteristics of media, recorders, test devices, and compatibility with CD-ROM readers be understood. This article summarizes the results of a CD-R media evaluation conducted by SIGCAT (the Federal Special Interest Group for CD-ROM Applications and Technology) and follow-on evaluations performed by the Data Distribution Laboratory at JPL. For this evaluation, 250 media samples from various manufacturers were recorded on several recorders at different record rates. Every byte of every disc recorded in the study was retievable on some, but not all, CD-ROM readers. We are confident that any commercially available media recorded on 2X recorders will provide a reliable archival media. We have, however, identified incompatibilities between single-speed (1X) recorders and phthalocyanine-based media and between high speed recorders (i.e. 4X and 6X recorders) and cyanine-based media. We recommend that the industry address the recorder and media incompatibilities and that a specification be developed for robust CD-R reader for use in archival applications.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The EPR spectra and structures of V(CO)6 and certain derivatives

Abstract An EPR spectrum observed in the liquid phase during the preparation of V(CO)4(PMe3)2 is ascribed to fac-V(CO)3(PMe3)3. Analysis of the isotropic (liquid) and frozen spectra leads to a 2A1 ground state in C3v symmetry for the free radical, with the unpaired electron in V 3dz2. The geometries and electronic structures of V(CO)6 and derivatives are discussed in the light of these new data.
Heterogeneous Chemistry of HONO on Liquid Sulfuric Acid: A New Mechanism of Chlorine Activation on Stratospheric Sulfate Aerosols

Heterogeneous chemistry of nitrous acid (HONO) on liquid sulfuric acid (H2SO4) was investigated at conditions that prevail in the stratosphere. The measured uptake coefficient (γ) of HONO on H2SO4 increased with increasing acid content, ranging from 0.03 for 65 wt % to about 0.1 for 74 wt %. In the aqueous phase, HONO underwent irreversible reaction with H2SO4 to form nitrosylsulfuric acid (NO+HSO4-). At temperatures below 230 K, NO+HSO4- was observed to be stable and accumulated in concentrated solutions (>70 wt % H2SO4) but was unstable and quickly regenerated HONO in dilute solutions (<70 wt %). HCl reacted with HONO dissolved in sulfuric acid, releasing gaseous nitrosyl chloride (ClNO). The reaction probability between HCl and HONO varied from 0.01 to 0.02 for 60−72 wt % H2SO4. In the stratosphere, ClNO photodissociates rapidly to yield atomic chlorine, which catalytically destroys ozone. Analysis of the laboratory data reveals that the reaction of HCl with HONO on sulfate aerosols can affect stratosp...
Rutgers In World War II

The story of the impact of World War II on American higher education has been all but ignored by American historians. Indeed, the only attempt at a comprehensive survey of that experience, made under the auspices of the American Council of Learned Societies, was published as far back as 1948. Why this subject has remained so neglected need not detain us now. Hopefully, it will some day be brought under careful scrutiny, and we may then gain yet another fruitful perspective on both the place of higher education in our culture and on the policies of the federal government in wartime.
Monitoring preload during liver transplantation

Liver transplantation is associated with major shifts incentral blood volume; therefore, monitoring preload is es-sential. Filling pressures (central venous pressure or pul-monary artery occlusion pressure) do not reﬂect preload[right ventricular end-diastolic volume (RVEDV) or leftventricular end-diastolic volume (LVEDV)] well becausethese pressures are affected not just by preload but alsoby changes in compliance of the heart. These compliancechanges can be quite signiﬁcant because of the changesin chest volume that are the result of surgical retractionand variable pressure on the diaphragm. Then, what arethe alternative methods of preload monitoring in the op-erating room? There are only two: thermodilution deter-mination of RVEDV and transesophageal echocardio-graphic estimation of RVEDV and LVEDV. Each of thesetechniques has advantages and disadvantages.The clinical determination of the right ventricularejection fraction (RVEF) and RVEDV became possible inthe early 1980s when American Edwards Laboratoriesmarketed a pulmonary artery catheter with a fast-re-sponse thermistor and an accompanying computer.That technology was based on intermittent injection ofa cold solution as a dye, and the principle of conserva-tion of energy allowed the calculation of RVEF and rightventricular volumes.
How Do Decision Frames Influence the Stock Investment Choices of Individual Investors

This study examines whether the framing mode (narrow versus broad) influences the stock investment decisions of individual investors. Motivated by the experimental evidence, which suggests that separate decisions are more likely to be narrowly framed than simultaneous decisions, we propose trade clustering as a proxy for narrow framing. Using this framing proxy, we show that investors who execute more clustered trades exhibit weaker disposition effects and hold better diversified portfolios. We also find that the degree of trade clustering is related to investors' stock preferences and portfolio returns. Collectively, the evidence indicates that the choice of decision frames is likely to be an important determinant of investment decisions.
Identification of the procedural steps that affect recovery of semi-volatile compounds by solid-phase extraction using cartridge and particle-loaded membrane (disk) devices

Abstract The experimental conditions are optimized for the recovery of a test mixture of neutral semi-volatile analytes on a cartridge and particle-loaded membrane (disk) device used for solid-phase extraction. The experimental variables investigated include: (1) selection of the type and volume of eluting solvent; (2) drying time between sample processing and elution of analytes; (3) the need for a preconditioning step prior to sample processing; (4) the need for an eluent permeation period prior to elution; (5) the use of organic solvents, surfactants and neutral inorganic salts as sample processing aids to enhance sample flow rates and recovery; (6) sample flow rate. The disk device is easier to work with, allows faster sample processing, requires a smaller eluent volume for analyte recovery, and provides recoveries virtually independent of the sample and eluent flow rates. On the other hand, preconditioning of the disk with an organic solvent prior to sample application is absolutely essential for normal operation, but is not essential when the cartridge is used. There is greater variability in results obtained on different cartridge devices because of differences in their packing density and heterogeneous flow characteristics. The recovery of analytes from the cartridge device shows significant flow rate dependence when the sample volume exceeds the breakthrough volume of the analyte. When used under optimized conditions both devices show excellent recovery of the analytes (>90%, except for dodecane on the cartridge device) and similar method precision.
Esterification of borate with NAD+ and NADH as studied by electrospray ionization mass spectrometry and 11B NMR spectroscopy

This paper describes for the first time the direct measurement of boric acid (B(OH)(3)) and borate (B(OH)(4) (-)) adduction to NAD(+) and NADH by electrospray ionization mass spectrometry (ESI-MS) and (11)B NMR spectroscopy. The analysis demonstrates that borate binds to both cis-2,3-ribose diols on NAD(+) forming borate monoesters (1 : 1 addition), borate diesters (1 : 2 addition) and diborate esters (2 : 1 addition), whereas, only borate monoesters were formed with NADH. MS in the negative ion mode showed borate was bound to a cis-2,3-ribose diol and not to the hydroxyl groups on the phosphate backbone of NAD(+), and MS/MS showed that the 1 : 1 addition monoester contained borate bound to the adenosine ribose. Boron shifts of borate monoesters and diesters with NAD(+) were observed at 7.80 and 12.56 ppm at pH 7.0 to 9.0. The esterifications of borate with NAD(+) and NADH were pH dependent with maximum formation occurring under alkaline conditions with significant formation occurring at pH 7.0. Using ESI-MS, the limit of detection was 50 micro M for NAD(+) and boric acid (1 : 1) to detect NAD(+)-borate monoester at pH 7.0. These results suggest esterification of borate with nicotinamide nucleotides could be of biological significance.
Low-density lipoprotein cholesterol lowering in the prevention of CHD: how low should we go?

The past 12 years have seen the publication of numerous randomized placebo-controlled studies using statins to lower low-density lipoprotein cholesterol (LDLC) to assess the efficacy of cholesterol lowering on cardiovascular events. Initial studies predominantly evaluated mortality or nonfatal myocardial infarctions and coronary heart disease (CHD) death in patients with known or presumed established coronary disease and moderately elevated to very elevated serum cholesterol concentrations. Subsequent investigations studied a broader spectrum of cardiovascular events as a composite primary end point in both primary and secondary prevention strategies in subjects with lower mean entry serum LDLC concentrations. These studies have generally shown a reduction in a composite end point of cardiovascular events, although not necessarily the more restricted end points used in previous studies. Although the LDLC mantra "lower is better" has been popularized in advertising and continuing medical education and suggested as an option in "very high risk" patients by the National Cholesterol Education Program Adult Treatment Panel, the precise target level for LDLC for optimal treatment has not been rigorously defined. Serum LDLC less than 100 mg/dL seems reasonable for patients with known atherosclerosis or at high risk for atherosclerosis (diabetes or presence of multiple risk factors). Serum LDLC less than 70 mg/dL may be a reasonable goal in the setting of acute coronary syndromes, but there are many problems with the data on which this recommendation is made. Furthermore, many advocates of "lower is better" seem oblivious to the potential downsides of more aggressive lipid-lowering therapy. The LDLC target in lower risk primary prevention is less clear. What is obvious is that moderate-dose statin therapy can lower CHD risk in primary prevention and secondary prevention with minimal side effects, and with the imminent availability of several generic statins, with great costeffectiveness.
Asymmetric Synthesis of γ-Hydroxy α,β-Unsaturated Amides via an AD-elimination Process; Synthesis of (+)-Coriolic Acid

Abstract An efficient, asymmetric synthetic route to γ-hydroxy α,β-unsaturated ketone and/or aldehyde equivalents is described. Thus, 3,4-dihydroxy N-methoxy-N-methyl amides are treated in a one pot process with thionyl chloride followed by DBU to give the corresponding γ-hydroxy α,β-unsaturated amides in good yields. Based on this methodology, a short sequence leading to natural (+)-Coroilic acid is presented.
Neurotoxicity of 25-OH-cholesterol on sympathetic neurons.

Abstract Cultured rat sympathetic neurons derived from postnatal rat superior cervical ganglia (SCG) were used to compare the neurotoxicity of several cholesterol oxides. The cholesterol oxides tested included: 7-beta-OH-, 7-keto-, 19-OH-, 22(R)-OH-, 22(S)-OH-, and 25-OH-cholesterol. These agents caused an acute as well as a delayed toxicity in sympathetic neurons with 25-OH-cholesterol appearing to be the most toxic. A time-dependent experiment indicated that 25-OH-cholesterol at 4 μg/ml (10 μM) was able to kill 50% of the cells in 36 h. Morphological studies indicate that most of the cells do not exhibit a structural change similar to that observed in neuronal programmed cell death. Whole-cell patch clamp recording of untreated controls and 25-OH-cholesterol (2 μg/ml)-treated cells indicated that this toxicity was not accompanied by significant changes in voltage-dependent calcium channel activity. A number of pharmacological agents including ethylene glycolbis (beta-aminoethyl ether) N,N,N′,N′-tetraacetic acid (EGTA), cycloheximide, KCl, vitamin E, and methyl-beta-cyclodextrin were able to prevent the 25-OH-cholesterol-induced cell death to various degrees. These results suggest that, in addition to causing pathological changes in cells directly involved in atherosclerosis, cholesterol oxides may induce neurotoxicity in sympathetic neurons.
Acute emphysematous cholecystitis: An analysis of ten cases

Summary Ten cases of acute emphysematous cholecystitis are reported. Three patients were treated nonoperatively and seven patients were operated upon. There was one death which occurred postoperatively but was not related to emphysematous cholecystitis per se. More frequent use of abdominal roentgenograms will aid in the early recognition of this entity. The roentgenographic criteria of emphysematous cholecystitis consist of the presence of gas in the lumen of the gallbladder or in the wall or pericholecystic tissues or combinations of these. The initiating factor in the development of emphysematous cholecystitis appears to be obstruction of the cystic duct. Bacteria are of secondary importance. Evidence is presented to support the position that patients with this condition should be treated in the same manner as patients with other forms of acute cholecystitis. Intensive antibiotic therapy should be started as soon as the diagnosis is made and continued until clinical manifestations of the disease have subsided. Surgical treatment is based on the persistence or progression of clinical findings during the course of treatment. Patients doing well during the period of preparation may be treated nonoperatively. This may be also considered for patients with severe coexisting disease.
Automated spike sorting using density grid contour clustering and subtractive waveform décomposition

In multiple cell recordings identifying the number of neurons and assigning each action potential to a particular source, commonly referred to as 'spike sorting', is a highly non-trivial problem. Density grid contour clustering provides a computationally efficient way of locating high-density regions of arbitrary shape in low-dimensional space. When applied to waveforms projected onto their first two principal components, the algorithm allows the extraction of templates that provide high-dimensional reference points that can be used to perform accurate spike sorting. Template matching using subtractive waveform decomposition can locate these templates in waveform samples despite the influence of noise, spurious threshold crossing and waveform overlap. Tests with a large synthetic dataset incorporating realistic challenges faced during spike sorting (including overlapping and phase-shifted spikes) reveal that this strategy can consistently yield results with less than 6% false positives and false negatives (and less than 2% for high signal-to-noise ratios) at processing speeds exceeding those previously reported for similar algorithms by more than an order of magnitude.
Moralizing and the Philosophy of Value Education

(1984). Moralizing and the Philosophy of Value Education. The Educational Forum: Vol. 48, No. 3, pp. 263-275.
Ant-inspired navigation in unknown environments

In contrast to most other ant species, desert ants (Cataglyphis fortis) do not use pheromones to mark their path. When returning from a foraging trip to their nest they navigate both by path integration and by visual landmarks. An egocentric navigation system based on path integration alone su ers from two major pitfalls: 1. It must run uninterrupted as long as the animal moves and 2. It is inherently susceptible to cumulative navigation errors. Hence, if the animal visited an area repeatedly, it is advantageous to take an occasional positional x by acquiring landmark-based geocentered (alocentric) information. Indeed desert ants and honeybees use such information in addition to path integration. On a familiar route, when ants can steer by visual landmarks, they adopt a xed and often circuitous path consisting of several separate segments that point in di erent directions. Such multi-segment journeys are composed partly of stored local movement vectors, which are associated with landmarks and are recalled at the appropriate place. During the experiments reported in [4] and [1], ants collected right before entering their nest after a foraging trip are deprived of their global vector. When these ants were placed at points along their familiar route, they were able to use previously seen visual features in order to return to their nest. It is believed [1], that two dimensional visual snapshots of landmarks along the homing path are stored in the memory of the ants and upon recognition they trigger a local vector that describes the transition to the next landmark on the way to the nest. These local vectors are also calculated based on odometry. They are links that point towards the direction of the next landmark along the path and are proportional to the distance between consecutive locations. Due to their limited length compared to the global vector the local transitions are more precisely learned and reproduced during foraging trips. The vision-based (local) navigation in ants works in parallel with global navigation. In order to ensure that an alternative navigation mechanism is available, desert ants use landmark-based navigation as the main method along familiar paths. They resort to global navigation only if the former fails, that is if in a dynamic environment landmarks are missing or are being occluded by new ones. If one of
Immobilization of the Copper Catalyst in Atom Transfer Radical Polymerization

Immobilization of the catalyst system for atom transfer radical polymerization (ATRP) on various silica and cross-linked polystyrene supports was studied. The catalyst system comprises a copper halide, complexed by various amines. The effect of size of support particles, the amount of immobilized catalyst, and the addition of Cu(II) species as deactivator in the polymerization were investigated. In all cases, polymerization occurred, but generally the reactions were not as well controlled in terms of molecular weight and polydispersities as homogeneous systems. The molecular weights did not match the predicted values, and polydispersities were high (1.5 < Mw/Mn < 10). However, control was improved by either an increase in catalyst concentration or the addition of deactivator still bound to support to the system. Potential reasons for the reduced control could be the low mobility of the supported catalyst and/or the steric hindrance and incompatibilities between the immobilized catalyst and the polymer cha...
EFFECT OF PHYSICAL ACTIVITY UPON CHOLESTEROL SYNTHESIS IN THE RAT LIVER.

Summary The effect of physical activity upon the synthesis of cholesterol and of fatty acids in rat liver was investigated. The serum cholesterol level, and cholesterol and fatty acids content in the liver was also determined. There was a significant increase of cholesterol and of fatty acid synthesis in the exercised rats as compared to the controls. There was no difference in the serum cholesterol level between the two groups studied. It is suggested, that the observed changes probably are due to an increased secretion of thyroid hormone.
Extramarital sex: Prevalence and correlates in a national survey

In the current study, data from a nationally representative sample of 884 men and 1,288 women (1994 General Social Survey, Davis & Smith, 1994) who have ever been married were analyzed with regard to incidence, prevalence, and correlates of extramarital sex (EMS). Men were more likely than women to report ever engaging in EMS (22.7% vs. 11.6%, p < .00001), yet, after correcting the probability value for multiple tests, the apparent gender difference regarding the proportion of respondents who had EMS during the past year was not statistically significant (4.1% vs. 1.7%, p < .008). Interestingly, there was no gender difference in lifetime incidence among respondents younger than 40 years of age. Except for the oldest cohort, lifetime incidence of EMS increased with age for men, whereas for women there was an apparently curvilinear relationship such that lifetime incidence of EMS was greatest among those 30–50 years of age. Those who have ever been divorced, and those with greater attitudinal acceptance of ...
Abnormal nuclear states: Higher-order corrections to the semiclassical solution

Quantum corrections to the semiclassical expression for the energy density of a dense fermion medium interacting with a scalar-meson field are computed. More specifically, all second-order terms in the previously introduced high-density, weak-coupling expansion are calculated. It is found that the resulting correction is not independent of the scalar-field vacuum expectation values, as was found to be the case for the first-order term.
Biogeochemical implications of labile phosphorus in forest soils determined by the Hedley fractionation procedure

Forest ecologists and biogeochemists have used a variety of extraction techniques to assess labile vs. non-labile soil P pools in chronosequences, the balance between biological vs. geochemical control of P transformations across a wide range of soil orders, the role of plants with either N-fixing or mycorrhizal symbionts in controlling soil P fractions, and to make inferences about plant-available P. Currently, variants of the sequential extraction procedure developed by M. J. Hedley and co-workers afford the greatest discrimination among labile and non-labile organic and inorganic P pools. Results of recent studies that used this technique to evaluate P fractions in forest soils indicate the following: (1) in intact, highly weathered forest soils of the humid tropics, Hedley-labile P values are several times larger than extractable P values resulting from mildly acidic extracting solutions which were commonly used in the past 2 decades; (2) pools of Hedley-labile P are several times larger than the annual forest P requirement and P required from the soil annually in both temperate and tropical forests; (3) long-term trends in non-labile P pools during pedogenesis are adequately represented by the Walker and Syers' model of changes in P fractionation during soil development. However, to better represent trends in pools that can supply plant-available P across forest soils of different age and weathering status, the paradigm should be modified; and (4) across a wide range of tropical and temperate forest soils, organic matter content is an important determinant of Hedley-labile P.
Alcohol and drug abuse prevention in Wisconsin public schools.

: This survey assessed the status of Wisconsin public school district programs designed to prevent alcohol and other drug related problems among students. The assessment involved surveying prevention program directors of 102 school districts that received grants for prevention initiatives since 1981. Most districts (70%) implemented programs at the elementary, middle, and senior high school levels. Typical program strategies involved combining information dissemination with refusal skill and self-concept development. School programs predominantly were school-based and did not systematically involve community members or agencies. The greatest obstacles to providing effective prevention services include high rates of alcohol and other drug use in homes and communities, denial of alcohol and other drug related problems among students, parents, and community members, and lack of staff time for prevention activities. Project directors indicated a need for schools to initiate greater involvement of parents, nonschool alcohol and drug abuse prevention agencies, and other community organizations in school efforts.
Potency of a tau fibrillization inhibitor is influenced by its aggregation state.

Abstract Tau fibrillization is a potential therapeutic target for Alzheimer’s and other neurodegenerative diseases. Several small-molecule inhibitors of tau aggregation have been developed for this purpose. One of them, 3,3′-bis(β-hydroxyethyl)-9-ethyl-5,5′-dimethoxythiacarbocyanine iodide (N744), is a cationic thiacarbocyanine dye that inhibits recombinant tau filament formation when present at submicromolar concentrations. To prepare dosing regimens for testing N744 activity in biological models, its full concentration–effect relationship in the range 0.01–60 μM was examined in vitro by electron microscopy and laser light scattering methods. Results revealed that N744 concentration dependence was biphasic, with fibrillization inhibitory activity appearing at submicromolar concentration, but with relief of inhibition and increases in fibrillization apparent above 10 μM. Therefore, fibrillization was inhibited ⩾50% only over a narrow concentration range, which was further reduced by filament stabilizing modifications such as tau pseudophosphorylation. N744 inhibitory activity also was paralleled by changes in its aggregation state, with dimer predominating at inhibitory concentrations and large dye aggregates appearing at high concentrations. Ligand dimerization was promoted by the presence of tau protein, which lowered the equilibrium dissociation constant for dimerization more than an order of magnitude relative to controls. The results suggest that ligand aggregation may play an important role in both inhibitory and disinhibitory phases of the concentration–effect curve, and may lead to complex dose–response relationships in model systems.
A Computer-Aided Spectroscopic System for Early Diagnosis of Melanoma

Early detection of melanoma, the deadliest type of skin cancer, has the potential to reduce morbidity and mortality. This paper presents an automated system for early identification of melanoma, which makes objective judgments based on quantitative measures. The system involves image processing, feature extraction, and support vector machine (SVM) classification. Images of 19 malignant melanoma and 168 benign subjects were collected by a spectroscopic device to reflect morphologies in diseased layers of skin. Features were extracted based on statistical parameters of pixel intensities and were fed into an SVM classifier. The system achieved 92% classification accuracy, 100% sensitivity and 92% specificity.
Axonal transport of labeled material into sensory nerve endings of cat carotid body

The origin of nerve endings on glomus cells in the carotid body has been the subject of much controversy in recent years. Specifically, the problem is whether these nerve endings, which contain clear-core ("synaptic") vesicles and mitochondria arise from sensory neurons in the petrosal ganglion or from efferent neurons located in the brain stem or elsewhere. To study this problem, [3H]proline was applied to cat petrosal ganglia, the animals were allowed to survive for 3 h-7 days, and the peripheral distribution of the label was analyzed by sample oxidation/scintillation counting and by EM autoradiography. The time courses of distribution of label along the nerves and the accumulation of label in the carotid body indicated the presence of fast, intermediate and slow components of axonal flow. EM autoradiographs of carotid bodies showed the label localized almost exclusively to nerve fibers and to nerve terminals on glomus cells. As much as 60--90% of the nerve terminals were labeled in a given ultrathin-section autoradiograph. Passive movement of label from the injection site, or fibers of passage (efferent) through the ganglion, did not contribute to the labeled material since administration of [3H]proline onto the desheathed nerve away from the ganglion was ineffective in labeling the carotid body. The results suggest that most, if not all, nerve terminals on glomus cells in cat carotid body arise from neurons in the petrosal ganglion.
The sources of PCBs to the Narragansett Bay estuary

The major rivers and municipal treatment facilities that discharge directly into Narragansett Bay have been surveyed to determine the amount of PCBs associated with their discharges under dry weather conditions. The Blackstone River, which empties into the northernmost sector of the bay system, was the largest source of riverine PCBs, contributing ∼ 70% of the 12 kg of Ar 1254 transported by the evaluated rivers per year. An additional 2.5 kg, annually, may be coming from freshwater inputs not explicitly measured in this study, giving a total fluvial input of ∼ 14 kg Ar 1254 per year. A single wastewater treatment facility, the Fields Point plant, which also discharges into the northern sector of the bay, contributed 70% of the 5.9 kg year−1 of Ar 1254 attributable to municipal inputs. Therefore, an estimated 20 kg of particulate Ar 1254 enters the bay, annually, from these sources, under dry weather conditions. Ar 1254 inputs represented ∼ 70% of the total Aroclors present in the samples (i.e., Ar 1242, Ar 1254, and Ar 1260). Of note was the almost exclusive presence of decachlorobiphenyl in the river samples.
Emission Spectrometric Determination of Isotopic Concentrations of Lithium

Isotopic concentrations of lithium have been determined by emission spectrometry using an optical scanning method. Results indicate that the method provides results with a precision of 1%, relative standard deviation.
Essential Role for the dsRNA-Dependent Protein Kinase PKR in Innate Immunity to Viral Infection

The double-stranded (ds) RNA-dependent protein kinase PKR is considered to play an important role in interferon's (IFN's) response to viral infection. Here, we demonstrate that mice lacking PKR are predisposed to lethal intranasal infection by the usually innocuous vesicular stomatitis virus, and also display increased susceptibility to influenza virus infection. Our data indicate that in normal cells, PKR primarily prevents virus replication by inhibiting the translation of viral mRNAs through phosphorylation of eIF2alpha, while concomitantly assisting in the production of autocrine IFN and the establishment of an antiviral state. These results show that PKR is an essential component of innate immunity that acts early in host defense prior to the onset of IFN counteraction and the acquired immune response.