cssi/SciSciGPT-SciSciNet huggingface dataset:
Right Ventricular Assist Device Support After Continuous Flow Left Ventricular Assist Device Implantation: Predicting a Poor Predictor

s S237 Pittsburgh, PA; 2Departments of Psychiatry, Epidemiology, & Biostatistic, University of Pittsburgh Medical Center, Pittsburgh, PA. Purpose: Right ventricular failure (RVF) after left ventricular assist device (LVAD) placement is often perilous. It has been hypothesized that in patients with advanced heart failure, RVF is linked to weight loss and measures of abnormal body composition, such as low body mass index (BMI). This postulate is examined in a cohort of LVAD supported patients. Methods: A retrospective analysis was performed of 114 continuous flow LVAD supported patients from 2004-2011. RVF was defined as need for right ventricular mechanical support or > 14 days of inotropic support postimplant. Three patient groups were identified based on the sample’s BMI distribution: lowest group (lowest quintile, BMI 33, n= 23). Kaplan-Meier analysis was used to compare the freedom from RVF; multivariate Coxregression analysis was performed to determine risk factors for RVF. Results: The BMI groups (lowest, intermediate, highest) were similar with regards to all pre-operative characteristics except age (56y, 59y, 47y, p= 0.002), non-ischemic/idiopathic diagnosis (22%, 1%, 9%, p= 0.004), emergent LVAD implantation (0%, 4%, 17%, p= 0.032), and pre-implant heart rate ( 104, 85, 95, p= 0.001). Figure 1 shows that freedom from RVF was significantly worse for the lowest BMI group compared to the intermediate BMI group (p= 0.019) and the intermediate and highest BMI groups combined (p= 0.021). There was no difference between the intermediate and highest BMI groups (p= 0.500) or the lowest and highest BMI groups (p= 0.185). Coxregression analysis revealed lowest BMI group (HR 2.519, p= 0.016, CI 1.187-5.347) and emergent device placement (HR 3.392, p= 0.028, CI 1.141-10.09) were independent risk factors for RVF. Conclusion: In LVAD patients, a low BMI is associated with heightened risk for RVF after device placement. Investigation of other potential markers of abnormal body composition may broaden our understanding of post-LVAD RVF.
Validation of surface EMG as a measure of intravaginal and intra-abdominal activity: implications for biofeedback-assisted Kegel exercises.

This study validates surface EMG as a measure of pelvic muscle and abdominal activity by showing its high correlation to internal pressure data. Using standardized scores, between-subjects correlation of perineal EMG and intravaginal pressure was r = .75, and the correlation of abdominal EMG and intra-abdominal pressure was r = .72. Discriminant validity was also demonstrated by showing low correlation between standardized abdominal and perineal EMG measurements (r = .10). A repeated measures multivariate analysis of variance demonstrated that visual and auditory biofeedback of EMG during pelvic floor contractions increases intravaginal pressure when compared with trials without biofeedback. Potential benefits of fabric electrodes include reduced invasiveness and risk and the ease with which patients can utilize this technology for home practice.
Teaching Family Systems Theory: A Developmental-Constructivist Perspective

Kegan’s (In over our heads: The mental demands of modern life, Harvard University Press, Cambridge, MA, 1994) description of an “In Over Our Heads” phenomenon has much to offer those who engage in teaching family systems theory and therapy, particularly in relationship to the tensions involved in the potential mismatch between the developmental demands of the curriculum and the orders of consciousness that characterize students’ responses to the material. Kegan’s notion of the “holding environment” and Kolb’s (Experiential learning: Experience as the source of learning and development, Prentice-Hall, Englewood Cliffs, NJ, 1984) theory of experiential learning are rich resources instructors can draw on to orient their teaching and curriculum more explicitly to supporting students on their developmental journey. In this article we provide examples of how to do that and also discuss the kinds of faculty development and changes in the program culture that are needed if “teaching for development” is to become more embedded in MFT programs.
Effect of fibrillar structure of pericanalicular and intercanalicular bone on x-ray absorption.

The apparent hypermineralization which is often seen adjacent to canaliculi (∼ 2000 A) and dentinal tubules in microradiographs may be the result of a reversal in orientation of microcanaliculi (∼ 500 A) and adjacent mineralized fibrils at these sites. Microcanaliculi and adjacent mineralized fibrils, as seen by electron microscopic surface replication, extended at right angles from canaliculi for a distance of about 1–2 μ. In contrast, beyond this zone microcanaliculi were also observed but were oriented at right angles to the microcanalculi that were closer to the canaliculi. Although the significance of the difference in orientation of microcanaliculi in pericanalicular as compared with intercanalicular regions is not known, we demonstrated that when a porous material is x-rayed parallel to and then at right angles to the longitudinal axis of the porous phase an apparent difference in density is observed. These findings suggest that the apparent hypermineralization of bone adjacent to canaliculi described in former investigations utilizing microradiography may be the result of a difference in orientation of microcanaliculi and adjacent mineralized fibrils rather than a true variation in mineral density.
A 4-GHz universal high-frequency on-chip testing platform for IP validation

This paper describes an on-chip intellectual property (IP) testing platform, Universal High Frequency Test structure (UHFTs), which makes logic, memory, and analog / mixed-signal IPs at-speed testable in the same testing structure. Any functional testing pattern can be loaded from an external pattern generator or a tester through standard 5-pin JTAG interfaces operating at 10MHz or below. The on-chip multichannel JTAG interface and elastic buffers convert an externally supplied pattern to an on-chip at-speed high-frequency pattern. The pattern can have address, data, and control fields. Each field is applied as input to a DUT in anyone of 16 available DUT sites, fully synchronized to the on-chip global clock. The output from the DUT is captured at-speed and stored in an output buffer. The content of the output buffer is read out to an external tester through the elastic-buffer and JTAG interfaces under a program control. UHFTs, implemented in TSMC 28-nm High Performance CMOS process, has been successfully used in digital, including ATPG, BIST, and vector-based tests with the capability of mixed-signal and analog tests. UHFTs have been designed with a frequency goal of 4 GHz in TSMC 28-nm CMOS process in the slow corner.
The violin arcs

Simple models for the violin arcs (the curves obtained by the sections of a curved violin surface by vertical planes along and across the length) in terms of polynomials and rational functions in rectangular coordinates have been suggested. The coefficients appearing in the corresponding equations are given as the solutions for the associated linear system generated by fitting no more than five data points. No more than five coefficients are required to generate the arcs. The graphs of these equations for the central longitudinal arcs and six lateral arcs at the conventional violin makers' position for both the top and the back plates have been given. The combined set of equations represent the surface of a curved violin plate and can be used to produce three dimensional graphs of various violin models (which however have not been presented in this article).
Stimulus secretion coupling in vitro: a rapid perfusion apparatus for monitoring efflux of transmitter substances from tissue samples.

Abstract An apparatus for monitoring efflux rates of specific substances from cellular preparations is described. Tissue samples (homogenates, subcellular fractions, small tissue slices, cell suspensions etc.) are placed on a filter, perfused with several different media sequentially and aliquots of the perfusate collected at intervals of 5 sec. Under maximum perfusion rates, the changeover in perfusion media is completed in less than 1 sec, produces no detectable disturbance of the sample and allows only minimal mixing of the different media. The apparatus has been used successfully to study stimulus secretion coupling during release of the neurotransmitter [ 14 C]γ-aminobutyric acid from synaptosomes.
High resolution, dynamic strain measurements with continuous fiber Bragg gratings for structural health monitoring

We describe the use of swept-wavelength interferometry (sometimes referred to as optical frequency domain reflectometry, OFDR) for high speed, distributed fiber-optic sensing. The technique utilizes continuous gratings written in single mode fiber facilitating high density distributed measurements of temperature or strain up 1 millimeter resolution. The technology used herein is capable of strain measurement rates of up to 1 KHz over the measurement domain with millimeter resolution. This technique shows great utility as a method for dynamic structural health monitoring, model simulation validation for mechanical prototypes, vibration monitoring or closed loop feedback control for process optimization.
A level set embedded interface method for conjugate heat transfer simulations of low speed 2D flows

Abstract This study examines the use of a level set based embedded interface method to simulate fluid–solid heat transfer processes using Cartesian grids. The flow field is described by the incompressible 2D Navier–Stokes equations using a vorticity–streamfunction approach. A fluid–solid coupling formulation for the thermal and momentum fields is developed that is robust, computationally efficient and second-order accurate. Solutions for several example problems are presented for flow over stationary and moving cylinders to bench mark the current approach. Heat transfer for an isolated cylinder and two cylinders in series are then examined to explore the Nusselt number dependence on cylinder spacing and unsteady conjugate heat transfer processes.
Systemic versus intraovarian progesterone replacement after luteectomy in rhesus monkeys: differential patterns of gonadotropins and follicle growth.

Similar to luteectomy (CLX) alone, systemic replacement of progesterone (P) to maintain circulating midluteal phase levels after CLX, and P withdrawal 10-11 days later were not accompanied by changes in serum FSH or LH levels. The next preovulatory gonadotropin surges, however, were delayed by about 10 days, relative to CLX alone. In contrast, a marked rise in serum FSH was observed after unilateral intraovarian P replacement at CLX, even though accompanying patterns of serum estradiol (E2) and P (and the interval to the next LH surge) were not different from those after CLX alone. Our findings indicate that a) P is the principal luteal factor inhibiting new follicle growth, b) P inhibition may be exerted, at least in part, on the ovaries directly, and c) an ovarian factor other than P or E2 may contribute to the regulation of FSH, and perhaps LH, secretion in this primate.
Amino acid sequence similarities between amyloid P component C1t and CRP

THE P component is a normal 9.5 S serum α1 glycoprotein composed of subunits that is found as a minor constituent of all types of amyloid deposits1,2. Painter et al.3 have described a 9.5 S α1 glycoprotein, C1t, composed of ten 23,000 molecular weight (MW) subunits, which may have an important role in the regulation of complement C1 function. Ultrastructural and immunological studies showed a striking resemblance between P and C1t (refs 3, 4). CRP is an acute phase reactant, present in many species which can interact with pneumococcal C-polysaccharide, choline phosphatides and various polycations to activate the complement cascade5,6. It is composed of a 23,000 MW subunit non-covalently linked as a pentamer7. A clear-cut structural relationship between C1t and CRP has been demonstrated by comparing amino terminal sequences7. Since all three molecules—P, C1t and CRP—have a similar ultrastructure, namely, a cyclic pentamer or a decameric double, the term ‘pentraxins’ has been proposed by Osmand et al. for this group of molecules7. We report here the characterisation and the amino terminal sequence of human P component. The P component is identical to C1t except for the absence of the first residue (His), thus providing additional evidence for a close evolutionary relationship for P, C1t and CRP.
Paper: Polygenic trait analysis by neural network learning

AI techniques have been applied to the domain of DNA sequence analysis in predicting or identifying certain specialized regions, in recognizing genes, and in understanding the evolutionary relationships between sequences. This paper focuses on a kind of genetic pattern recognition, namely, the problem of identifying the gene combinations (patterns) causally related to a given trait determined by multiple genes (a so-called polygenic trait). A novel approach is presented which combines neural-network and knowledge-based techniques. The neural network is trained to predict the trait and then the knowledge embedded in the network is decoded into symbolic patterns. This hybrid approach is evaluated in the domain of identifying genes of insulin dependent diabetes mellitus. The consistency between the results with this approach and those reported in genetic literature supports the viability of this approach.
The new american joint committee on cancer and international union against cancer tnm classification of prostate cancer

Background. The 1992 American Joint Committee on Cancer and International Union Against Cancer TNM classification system for prostate cancer includes categories for the increasingly common nonpalpable cancers detected by serum prostate specific antigen (PSA) levels and transrectal ultrasonography (TRUS), but few details have been published about the pathologic features and prognosis of such cancers. Methods. We analyzed the clinical and pathologic features of 400 patients with clinical Stages T1-T3, NO or NX, MO cancer treated with radical prostatectomy. We compared volume, grade, extension, and prognosis of cancers detected by PSA or TRUS to those detected by the traditional techniques of transurethral resection (TURP) or digital rectal examination. Results. As clinical stage increased in the TNM classification, the volume, grade, and frequency of extraprostatic spread increased significantly. The 33 nonpalpable, nonvisible tumors detected because of an elevated PSA (T1c) were similar in size and frequency of extension to TURP-detected (T1a-b) cancers, but more often were poorly differentiated (52% vs. 22%) (P < 0.03). No T1c cancer has recurred to date. Nonpalpable T2 cancers detected by TRUS (n = 42) were significantly more likely (47% vs. 18%) to extend outside the prostate than were T1c cancers. Compared to palpable T2 cancers, TRUS-detected T2 cancers were smaller but were similar in grade, extension, and prognosis. T3 cancers were extensive and recurred rapidly; only 6% were confined to the prostate. In contrast, 24% of the T1 and 57% of the T2 cancers were not confined (± pT3), but only 6-9% of T1-T2a cancers exhibited advanced pathologic features (seminal vesicle invasion or lymph node metastases), compared with 26% of the T2b-c cancers. Conclusion. The new TNM staging system provides appropriate new categories for inclusion of nonpalpable cancers detected by PSA and ultrasound. This new classification is logical and generally reflects the pathologic extent and prognosis of these tumors, although cancers in the advanced T2 categories are often more extensive.
Directional heterogeneity of environmental disamenities: the impact of crematory operations on adjacent residential values

A hedonic study of residential house sales in Rawlins, Wyoming, was conducted to estimate the impact of an environmental shock from a new point source upon adjacent residential property values. We use a unique data base of house sale prices and associated house attributes, including structural and neighbourhood characteristics and geographic distances and directions from the source of the shock, atmospheric emissions from a new crematory. Our data spans 27 months of house sales: 7 months before, and 20 months after the startup of crematory operations. Results indicate that proximity, measured both in terms of direction and distance from the crematory, imparts a statistically significant negative impact on average house sale prices–an increase of 0.3 to 3.6% of average sale price for every one-tenth mile increase up to one-half mile in distance away from the crematory, but depending on direction from the crematory. This distance benefit increases somewhat with calendar time only for houses located west of ...
A Computational Theory of Learning Causal Relationships

I present a cognitive model of the human ability to acquire causal relationships. I report on experimental evidence demonstrating that human learners acquire accurate causal relationships more rapidly when training examples are consistent with a general theory of causality. This article describes a learning process that uses a general theory of causality as background knowledge. The learning process, which I call theory-driven learning (TDL), hypothesizes causal relationships consistent both with observed data and the general theory of causality. TDL accounts for data on both the rate at which human learners acquire causal relationships, and the types of causal relationships they acquire. Experiments with TDL demonstrate the advantage of TDL for acquiring causal relationships over similarity-based approaches to learning: Fewer examples are required to learn an accurate relationship.
Emerging Trends in Failures Involving EPS-Block Geofoam Fills

Expanded polystyrene (EPS) is a closed-cell polymeric (“plastic”) foam that, in its generic block-molded form, has seen increasing use worldwide as a cellular geosynthetic in the geofoam category. This growth is due to the fact that block-molded EPS is unique among geofoam products for the large and diverse variety of functional applications for which it is technically well suited and relatively economical as well as for its proven long-term in-ground durability. However, as often happens when there is rapid growth in a technology based on a generic commodity product such as block-molded EPS, its use outstrips the acquisition of critically important technical knowledge by end users. This can result in inefficient and even incorrect use that can lead to failures in project applications. There is evidence that this cause and effect is currently occurring in the United States at least for some widely used EPS-block geofoam functional applications such as lightweight fill for road construction. This paper con...
Shock Waves and Plume Prediction of a Rocket Thruster With an Attached Panel

Reynolds-Averaged Navier-stokes (RANS) numerical simulations are performed to predict the supersonic flow field induced by a H2-O2 rocket thruster with an attached panel, under a variety of operating conditions. The simulations have captured physical details of the flow field, such as the plume formation and expansion, formation of a system of shock waves and their effects on the temperature and pressure distributions on the walls. Comparison between the computed results for 2-D and adiabatic walls and the related experimental measurements for 3-D and cooled walls shows that the results of the simulations are consistent with those obtained from the related rig tests.Copyright © 2003 by ASME
A STUDY ON MALLORY BODIES

Mallory bodies (MBs) were isolated from the livers of 8 alcoholic patients and a malignant hepatoma occurring in a non-alcoholic patient. MBs were isolated in large quantity and high purity. The isolates were devoid of liver cell organelles except in the case of malignant hepatoma where dense and membranous material resembling nuclear substances and endoplasmic reticulum were found. The "nuclear" material had continuity with MBs. Electron microscopic examination suggested the presence of a dense body and very fine filaments within in situ and isolated MBs in addition to the tubular structure of so-called MB fibers. Amino acid analysis indicated that the major component of MBs is a protein which does not contain unusual amino acids or any particular amino acid in a large quantity to characterize this protein. The isolated fractions were solubilized in 6 M guaindine hydrochloride by sonication or in 1% sodium dodecyl sulfate (SDS) with 2 mercaptoethanol and 8 M urea. The solubilized MB protein produced 3 peaks by Sephadex G 100 chromatography and at least five intense protein bands by SDS polyacrylamide gel electrophoresis. Serum sample and the fractions from control livers contained several protein bands which were similar to the major components of isolated MB protein. These morphological and biochemical findings suggest that MBs are not homogeneous protein, but they are probably complexes of various proteins and that some components of MBs are present in normal hepatocytes.
Dramatic Attenuation of Hypusine Formation on Eukaryotic Initiation Factor 5A During Senescence of IMR-90 Human Diploid Fibroblasts

Deoxyhypusine synthase catalyzes the conversion of lysine to deoxyhypusine residue on the eukaryotic initiation factor 5A (elF-5A) precursor using spermidine as the substrate. Subsequent hydroxylation of the deoxyhypusine residue completes hypusine formation on elF-5A. Hypusine formation is one of the most specific polyamine-dependent biochemical events in eukaryotic cells. Although changes in polyamine metabolism have been demonstrated in human diploid fibroblasts during senescence (Chen and Chang, 1986, J. Cell. Physiol., 128:27-32.), it is unclear whether or not polyamine-dependent hypusine formation itself is an age-dependent biochemical event. In the present study, hypusine-forming activity was measured by a radiolabeling assay in cells whose polyamines have been depleted by prior treatment of alpha-difluoromethyl ornithine (DFMO). In addition, an in vitro cross-labeling assay was developed for simultaneous measurement of the deoxyhypusine synthase activity and protein substrate (elF-5A precursor) amount. We showed that the hypusine-forming activity in low-passage presenescent IMR-90 cells [population doubling level (PDL) = 15-23, termed young cells] was prominently induced by serum whereas little or no hypusine-forming activity could be detected in late-passage senescent cells (PDL = 46-54, termed old cells). The striking difference in hypusine-forming activity between young and old cells was due to changes in both deoxyhypusine synthase activity and elF-5A precursor amount in IMR-90 cells during senescence. However, Northern blot analysis showed no significant difference in the elF-5A messenger RNA (mRNA) between young and old cells, suggesting that the age-dependent attenuation of elF-5A precursor protein may be regulated at either translational or post-translational level.
Surface damage evolution and optical performance of beadblasted fused silica

Abstract Optical measurements were made with improved quantitative estimation of the damage evolution of the fused silica surface. The mechanical damage was induced by a sandblasting system using spherical glass beads. Development of the surface damage was measured by the changes in the specular transmission and reflection, and by inspection using a surface profilometer and a scanning electron microscope. The changes in the transmittance versus the duration of beadblasting were measured for single fused silica slides and for a few consecutive slides. Theoretical expressions were developed to describe the stages in surface deterioration and conclusions were obtained for the fused silica surface removal mechanism.
The acoustic features of gorilla double grunts and their relation to behavior

Mountain gorillas (Gorilla gorilla beringei) give double-grunts to one another in a variety of situations, when feeding, resting, moving, or engaged in other kinds of social behavior. Some double-grunts elicit double-grunts in reply whereas others do not. Double-grunts are individually distinctive, and high-ranking animals give double-grunts at higher rates than others. There was no evidence, however, that the probability of eliciting a reply depended upon either the animals' behavior at the time a call was given or the social relationship between caller and respondent. The probability of eliciting a reply could be predicted from a double-grunt's acoustic features. Gorillas apparently produce at least two acoustically different subtypes of double-grunts, each of which conveys different information. Double-grunts with a low second formant (typically 1600 Hz) are given by animals within 5 s of a call from another individual and rarely elicit replies. © 1994 Wiley-Liss, Inc.
Multipole (E1, M1, E2, M2) transition wavelengths and rates between states with n⩽6 in helium-like carbon, nitrogen, oxygen, neon, silicon, and argon

Abstract Transition wavelengths and rates are given for E1, E2, M1, and M2 transitions between singlet and triplet S, P, D, and F states in heliumlike ions of astrophysical interest: carbon, nitrogen, oxygen, neon, silicon, and argon. All possible transitions between states with n⩽6 are considered. Wave functions and energies are calculated using the relativistic configuration-interaction (CI) method including both Coulomb and Breit interactions. For transitions to the ground state, the present theoretical wavelengths agree to five digits with precise measurements.
The role of the corpus callosum in the development of interocular eye alignment and the organization of the visual field in the cat

In young cats, the posterior portion of the corpus callosum was sectioned 13–29 days after birth. The animal's eyes were photographed at weekly intervals for six months using the pupil-reflex method. From the corneal reflection evident in the photographs the degree of alignment for the optical axes of each cat was estimated (Sherman, 1972). The 17 experimental cats all showed a significant tendency toward permanent divergent strabismus, as compared to six normal cats. The limits of the visual field were determined for both groups of cats using a perimetry technique similar to that of Sprague and Meikle (1965) and Sherman (1973). With one eye open normal cats responded from 90 ° ipsilateral to 45 ° past the vertical midline into the contralateral visual field. With either eye the experimental cats responded from 90 ° ipsilateral to approximately the vertical midline. The loss of visual responsiveness is within the contralateral region of the normally binocular zone. Three cats received the same operation at 9, 13, or 20 months old. Eye alignment and visual field perimetry were unaffected by the surgery. It is not known whether the observed abnormalities result from arrested development, or disruption of intrinsically determined ocular alignment.
C.S.Peirce and the Early Phases of Model-theoretic Logic

This paper focuses on C. S. Peirce's philosophy of logic and mathematics pertinent to the so-called model-theoretic tradition in formal logic. While it is common to trace the development of model-theoretic logic back to Peirce, closer textual study tends to reveal that there is a gap between the work of Peirce and what was later achieved by, among others, Lowenheim and Skolem. As Peirce's nonstandard model of the theory of reals suggests, however, Peirce does belong to the model-theoretic tradition at least in a broad sense. This paper thus makes efforts to better situate Peirce in the model-theoretic movement by considering Cantor's influence on Peirce, which most probably motivated Peirce to develop his nonstandard model of the reals. The paper also endeavors to shed light on Peirce's highly original ideas regarding the logic of mathematics seen in this particular context.
MicroRNA-192 and -215 are upregulated in human gastric cancer in vivo and suppress ALCAM expression in vitro

MicroRNA-192 and -215 are upregulated in human gastric cancer in vivo and suppress ALCAM expression in vitro
Executive-attentional uncertainty responses by rhesus macaques (Macaca mulatta).

The uncertainty response has been influential in studies of human perception, and it is crucial in the growing research literature that explores animal metacognition. However, the uncertainty response’s interpretation is still sharply debated. The authors sought to clarify this interpretation using the dissociative technique of cognitive loads imposed on ongoing discrimination performance. Four macaques (Macaca mulatta) performed a Sparse-Dense discrimination within which an uncertainty response let them decline difficult trials or a middle response let them identify middle stimuli. Concurrent memory tasks were occasionally overlain on ongoing discrimination performance. The concurrent tasks disrupted macaques’ uncertainty responses far more than their sparse, middle, or dense discrimination responses. This dissociation suggests that the uncertainty response is a higher-level, decisional response that is particularly dependent on working memory and attentional resources. This is consistent with the theoretical possibility that the uncertainty response is an elemental behavioral index of uncertainty monitoring or metacognition.
Catalyst size distributions from X-ray diffraction

Both the average metal crystallite size and the size distribution can be obtained from Fourier analysis of X-ray diffraction peaks from supported metal catalysts. The average size is obtained from the first derivative of the cosine coefficients (after correction for instrumental effects and microstrain), and the distribution from the second derivative. The advantage of this procedure over, say, electron microscopy is the good sampling associated with a large cross-section of X-ray beam. Furthermore, the weighting of the distribution determining the average size is the same as for chemisorption, so that direct comparisons are possible, / where L is the size.
Purification and crystallization of precursors and autoprocessed enzymes of Flavobacterium glycosylasparaginase: an N-terminal nucleophile hydrolase

Glycosylasparaginase (GA) represents a novel group of proteins that are activated by self-catalyzed peptide-bond cleavage from a single-chain precursor to yield the two subunits required for hydrolase activity. The wild-type GA precursor autoproteolyzes spontaneously into α and β subunits. Strategies are reported here for purification to homogeneity of GA from Flavobacterium meningosepticum in both single-chain precursor and mature (autoprocessed) forms. The recombinant proteins crystallize in different space groups: P1 and P21 for the precursor and mature enzymes, respectively. The precursor crystals diffract to 1.9 A resolution with laboratory X-ray radiation.
diabetes‐induced reduction in the hepatic accumulation of 70‐kDa dextran: Role of hyperglycemia and hypoinsulinemia

Abstract In vivo studies were conducted in rats to determine the role of hyperglycemia and hypoinsulinemia in the previously reported reduction in the hepatic accumulation and increase in the serum concentrations of 70‐kDa fluorescein‐dextran (FD‐70) in diabetic (D) rats. The serum, urine, and hepatic concentrations of FD‐70 were measured by size exclusion chromatography after iv administration of single doses (5 mg/kg) of FD‐70. Intravenous administration of a single 2 IU/kg dose of insulin to D rats at time zero or 4 h after the administration of FD‐70 resulted in an increase in some and no change in other animals in their rate of elimination of FD‐70 from serum. The presence or absence of a significant insulin effect on the disposition of FD‐70 in these animals was, respectively, associated with the presence or absence of a significant insulin‐induced hypoglycemic effect. Fasting D rats for 24 h caused normoglycemia, and subsequently, the disposition of FD‐70 became similar to that in nondlabetic (ND) rats. Likewise, ip injections of glucose to ND rats rendered them hyperglycemic, and the disposition of FD‐70 in these rats became similar to that in untreated D animals. However, iv injection of glucose, which did not result in sustained hyperglycemia, did not change the disposition of FD‐70 in ND rats. Further, the disposition of FD‐70 remained unaffected by an iv 2 IU/kg dose of insulin administered to ND rats at time zero. Considering all animals, there was a significant negative relationship between the 12‐h hepatic recovery of FD‐70 and the area under the serum concentration‐time curves of glucose. It is concluded that the reduction in the hepatic accumulation of FD‐70 in D rats is due to hyperglycemia and not hypoinsulinemia.
Differences in seawater particulate organic carbon concentration in samples collected using small- and large-volume methods: the importance of DOC adsorption to the filter blank

Particulate organic carbon (POC) data collected by small-volume (∼1–2 l) bottle filtration and large-volume (∼100–600 l) methods are compared for samples from the central Arctic, Equatorial Pacific, Equatorial and South Atlantic, Gulf of Maine, and Narragansett Bay. Small-volume samples were collected using Niskin® and Go-Flo® bottles and large-volume samples were collected using in situ pumps and large-volume bottle filtration. Results indicate that small-volume bottle POC data are often greater than large-volume results, by as much as 2–4 times, in regions with low POC concentration (<∼5 μM). The implication is that POC concentrations determined by small-volume bottle filtration in regions characterized by low POC concentrations, i.e., in the majority of surface open ocean and deep waters, may be erroneously high. We suggest the most likely explanation is adsorption of DOC to the filter, which is rarely quantified yet can significantly increase the filter blank. The magnitude of DOC adsorption was assessed using coastal seawater by determining the y-intercept of a plot of the organic carbon retained by a glass-fiber filter against the volume filtered. The intercept was approximately two-fold greater than the precombusted filter blank, which we attribute to DOC adsorbed to the filter. Thus, when seawater POC concentrations are similar to, or less than, the precombusted filter blank, not correcting for the true in situ blank can result in erroneously high POC concentrations. To avoid this artifact, we recommend using large-volume sampling methods, which result in a greater quantity of POC per unit area of the filter relative to the filter blank. When large-volume filtration is not possible, we recommend a simple method to evaluate the true in situ filter blank.
STUDY OF THE PROPERTIES OF SIMPLE ENAMEL GLASSES1

Three component glasses of the systems Na2–B2O3–SiO2 and Na2O–PbO–SiO2 were investigated as to acid-resisting properties. An increase in silica in general improves the acid resistance. The effect of Na2O, B2O3, and PbO on the acid resistance of an enamel is dependent on the composition to which these oxides are added. Some of these enamels showed considerable promise as acid-proof enamels.
Comparison of DNA adduct formation in mice fed coal tar or benzo[a]pyrene

Coal tar is a complex mixture containing hundreds of compounds, including the carcinogenic polycyclic aromatic hydrocarbon, benzo[a]pyrene. In order to compare the metabolic activation of a single carcinogen versus a complex mixture containing the carcinogen, we determined the DNA adduct profiles in B6C3F1 mice fed doses of coal tar or benzo[a]pyrene at concentrations corresponding to the amount of benzo[a]pyrene found in the respective coal tar treatments. DNA adduct formation was quantified in liver, lungs and forestomach by 32P-postlabeling and was found to increase as a function of dose in each tissue with both coal tar and benzo[a]pyrene. In mice fed benzo[a]pyrene, a major adduct was detected with the same elution characteristics by TLC and HPLC as the major adduct, 10 beta-(deoxyguanosin-N2-yl)-7 beta, 8 alpha, 9 alpha-trihydroxy-7,8,9,10- tetrahydrobenzo[a]-pyrene (dG-N2-BPDE), obtained from reacting (+/-)-antibenzo[a]pyrene-7,8- dihydrodiol-9,10-epoxide (BPDE) with DNA. DNA binding was in the order forestomach > or = liver > lung, except at the highest dose group where the order was liver > forestomach > lung. In mice fed coal tar, a diagonal zone of radioactivity with a number of discrete adducts was observed. One area of radioactivity contained the major BPDE adduct, dG-N2-BPDE, based on co-elution by TLC and HPLC with the synthesized adduct. Total DNA binding was greater in the coal tar-fed mice than in the mice fed benzo[a]pyrene, and the adduct levels were in the order lung > liver > forestomach. These results indicate that there are tissue-specific differences in the activation of coal tar components when compared to a representative carcinogen contained within the mixture.
Effective Treatment of Narcolepsy with Codeine in a Patient Receiving Hemodialysis

A 64-year-old man with narcolepsy could not take stimulant drugs due to coronary heart disease. In the past he noted improvement in alertness when taking codeine for pain, but this was eventually discontinued. After he developed end-stage renal disease, and because the use of stimulants in this setting may be difficult, treatment with codeine was again initiated. This resulted in dramatic improvement in alertness and substantial reduction of cataplexy. Because it is simple to use and familiar to most physicians, codeine may be the drug of choice for narcoleptic patients who are undergoing hemodialysis.
Evidence for surface perception of abscisic acid by rice suspension cells as assayed by Em gene expression

Abstract To determine if the initial perception of abscisic acid (ABA) occurs at the surface of plant cells, embryogenic rice ( Oryza sativa L.) suspension cells have been treated with ABA covalently linked to bovine serum albumin (BSA). Although the ABA–BSA conjugate does not penetrate the plasma membrane, we demonstrate that the conjugate induces the accumulation of transcripts from the ABA-inducible Em gene. Protoplasts containing the Em promoter linked to the reporter gene β -glucuronidase (GUS) also respond to the ABA–BSA conjugate by increasing GUS activity in a dose-dependent manner. Data are presented which indicate that the ABA–BSA conjugate is not degraded during incubation with rice suspension cells. This suggests that release of ABA from the conjugate and its uptake into the cell as free ABA cannot account for the increased levels of Em mRNA. Furthermore, we demonstrate that at a neutral pH, where free ABA does not cross the plasma membrane, Em transcript levels increase in response to either ABA or the ABA-BSA conjugate. We conclude that ABA perception at the surface of rice suspension cells leads to internal signals which induce Em gene expression.
Phase-modulation laser spectroscopy

A novel phase-modulation technique which permits subkilohertz-laser stability and new levels of precision in laser spectroscopy was reported recently. For spectroscopy, the basic arrangement consists of a combination of an optical pump and a probe field which is phase modulated. The pump prepares the atomic sample by burning a narrow hole within the atom's inhomogeneous line shape, and the probe beam samples the prepared hole when its modulation sidebands are swept into resonance. Off resonance, the probe is balanced as pairs of sidebands produce heterodyne beat signals of opposite phase which just cancel. On resonance, the balance is upset and yields a nonvanishing beat signal with a Lorentzian absorption or dispersion line shape and with residual noise approaching the shot noise limit. Here we investigate the theory of phase-modulation spectroscopy. We treat the nonlinear response of an atomic two-level quantum system subject to an intense pump and a weak copropagating or counterpropagating phase-modulated probe beam. The density-matrix equations of motion are solved by a Laplace-transform method and by the novel use of a translation operator which allows the infinite hierarchy of coupled equations to close. A solution equivalent to the rate-equation result is developed and coherence corrections are found which predict new resonances that have just been detected in this laboratory. The delayed pump-probe technique encountered in solid-state laser spectroscopy is analyzed in this context for two- and three-level quantum systems. The response of a Fabry-Perot cavity to a phase-modulated light wave is examined also and reveals an unexpected absorption feature.
Nutrition and colon cancer prevention

Purpose of reviewIn spite of improvements in care of colon cancer patients, prevention may enable potential patients to avoid cancer therapy. Although screening is direct and effective, dietary modification or low-risk chemopreventive agents might prevent colon cancer development. In this article, w
Cloning and characterization of the promoter of baboon XRCC1, a gene involved in DNA strand-break repair

The DNA repair geneXRCC1 was the first cloned human DNA repair gene involved in resistance to ionizing radiation. Previous studies have shown that rodent and baboon homologs ofXRCC1 are expressed in all tested tissues with significantly higher levels in testis. Furthermore, expression of murineXRCC1 is most abundant in pachytene spermatocytes and round spermatids. To begin to study regulation ofXRCC1 expression, the 5′ region of baboonXRCC1 was cloned and characterized. 400 bp of 5′-flanking region showed the greatest promoter activity, while −194 to −8 bp of the 5′-flanking region displayed core promoter activity in transient transfection assays. A comparison between baboon and human 5′-flanking sequences in the core promoter region revealed a potential CAAT-box, an imperfect CREB-binding site and two putative Sp1-binding sites. Results from transient transfection assays in which each putative binding site was individually mutated, indicated that the distal Sp1-binding site has a functional role in transcription. In comparison, both putative Sp1-binding sites bound protein(s) from HeLa cell nuclear extractsin vitro. In vitro binding was lost when mutated Sp1 sites were used in gel mobility shift assays. Finally, anti-Sp1 antibodies produced mobility supershifts, thereby indicating Sp1 or an Sp1-like protein bound to the DNA fragmentin vitro.
Effect of Bilayer Cholesterol and Surface Grafted Poly(Ethylene Glycol) on pH-Induced Release of Contents from Liposomes by Poly(2-Ethylacrylic Acid)

AbstractLiposomal delivery systems have yet to reach the levels of burst release of drug at a diseased site necessary to achieve high local therapeutic levels. A pH sensitive, triggered release system, is one mechanism which shows great promise, especially for use in low pH environments such as tumor interstitial space and endosomes. The pH-sensitive polymer, poly(2-ethylacrylic acid) (PEAA), has been shown to disrupt liposome membranes and release entrapped contents, dependent on membrane compressibility. By adding cholesterol to lipid bilayers, the pH at which entrapped contents were released was reduced from pH 6.7 for a pure lipid system, to pH 6.0 for a cholesterol-saturated system. This decrease in pH, corresponding to an increase in the degree of protonation (i.e. degree of hydrophobicity), was directly correlated to the increase in the elastic area expansion modulus of the bilayers. These results are presented in terms of a balance between polymer solubility and membrane expansion. In a separate e...
A Fresh Look at the Discriminant Function Approach for Estimating Crude or Adjusted Odds Ratios

Assuming a binary outcome, logistic regression is the most common approach to estimating a crude or adjusted odds ratio corresponding to a continuous predictor. We revisit a method termed the discriminant function approach, which leads to closed-form estimators and corresponding standard errors. In its most appealing application, we show that the approach suggests a multiple linear regression of the continuous predictor of interest on the outcome and other covariates, in place of the traditional logistic regression model. If standard diagnostics support the assumptions (including normality of errors) accompanying this linear regression model, the resulting estimator has demonstrable advantages over the usual maximum likelihood estimator via logistic regression. These include improvements in terms of bias and efficiency based on a minimum variance unbiased estimator of the log odds ratio, as well as the availability of an estimate when logistic regression fails to converge due to a separation of data points. Use of the discriminant function approach as described here for multivariable analysis requires less stringent assumptions than those for which it was historically criticized, and is worth considering when the adjusted odds ratio associated with a particular continuous predictor is of primary interest. Simulation and case studies illustrate these points.
A survey of collaborative filtering techniques

As one of the most successful approaches to building recommender systems, collaborative filtering (CF) uses the known preferences of a group of users to make recommendations or predictions of the unknown preferences for other users. In this paper, we first introduce CF tasks and their main challenges, such as data sparsity, scalability, synonymy, gray sheep, shilling attacks, privacy protection, etc., and their possible solutions. We then present three main categories of CF techniques: memory-based, modelbased, and hybrid CF algorithms (that combine CF with other recommendation techniques), with examples for representative algorithms of each category, and analysis of their predictive performance and their ability to address the challenges. From basic techniques to the state-of-the-art, we attempt to present a comprehensive survey for CF techniques, which can be served as a roadmap for research and practice in this area.
Percent Free Prostate-Specific Antigen: Entering a New Era in the Detection of Prostate Cancer

The introduction of prostate-specific antigen (PSA) testing into clinical medicine in 1986 revolutionized the management of patients with prostate cancer. The major limitation of this tumor marker stems from its inability to provide a clear distinction between benign prostate disease and prostate cancer, especially in patients with upper limit of normal or slightly increased PSA values. Recent research has established that PSA exists in the serum in several molecular forms. Patients with benign prostatic hyperplasia have more of the free form, whereas those with prostate cancer have more of a complexed form (PSA covalently bound to alpha 1-antichymotrypsin). Several investigations have now confirmed that determining percent free PSA (proportion of free PSA to total PSA) enhances the ability of PSA testing to distinguish between prostate cancer and benign prostatic hyperplasia. In addition, percent free PSA seems to have the greatest clinical significance in patients whose total PSA values range from 2.5 or 3.0 ng/mL (lower limit) to 10.0 ng/mL (upper limit). When the total PSA value is in the normal range (2.5 or 3.0 to 4.0 ng/mL), percent free PSA makes PSA a more sensitive test (increases cancer detection). When the total PSA level is minimally increased (4.1 to 10.0 ng/mL), percent free PSA makes PSA a more specific test (eliminates performance of unnecessary prostate biopsies). Although further work remains, it seems that percent free PSA can substantially improve the clinical utility of the PSA test for detecting early, curable prostate cancer.