cssi/SciSciGPT-SciSciNet huggingface dataset:
Factors associated with primary vein graft occlusion in a multicenter trial with mandated ultrasound surveillance

Objective Even in the setting of duplex ultrasound (DUS) surveillance, a significant number of lower extremity vein bypass grafts (LEVBGs) become occluded as a first event. We sought to identify factors that may contribute to these primary occlusions. Methods This was a retrospective analysis of the Project of Ex Vivo Graft Engineering via Transfection III (PREVENT III) multicenter randomized clinical trial, in which 1404 patients with critical limb ischemia (CLI) underwent LEVBG with 1-year follow-up. Subjects were to undergo DUS at regular intervals (1, 3, 6, and 12 months), with reintervention based on prespecified DUS criteria. Patients who had nontechnical graft occlusion as the initial graft-related event were identified, and multivariate analysis was used to determine factors associated with primary graft occlusion. Results Primary vein graft occlusion occurred in 200 subjects and accounted for 36% of all primary patency events and 64% of all graft occlusions in the trial. Primary occlusion events were evenly distributed throughout the first postoperative year. Rates of recurrent CLI, loss of secondary patency, and major amputation in those with primary occlusion were 55%, 79%, and 22% respectively as compared to 18%, 10%, and 10% for subjects without primary occlusion ( P Conclusions Among patients undergoing LEVBG for CLI, almost half of primary patency events are occlusions even in the setting of a DUS surveillance protocol. African Americans, patients with smaller-diameter grafts, and those who are nonadherent with surveillance ultrasound are at increased risk. Failure to intervene on critical findings, and lack of sensitivity of DUS threshold criteria to predict thrombosis, are also important contributors. These findings suggest that prevention of vein graft thrombosis requires further improvements in risk stratification, surveillance, and the timing of reinterventions.
Linear control of nonlinear processes: recent developments and future directions

Abstract Virtually all chemical processes are nonlinear, but for several of them linear feedback control is adequate. Therefore, before nonlinear controller design is attempted, it is natural to ask ‘when is linear control adequate for a nonlinear process?’ to ensure favorable cost/benefit ratio. Consequently, methods are needed that quantify the nonlinearity of a process within the context of assessing whether linear control is adequate or nonlinear control is warranted. In this work we summarize efforts towards this end and elaborate on our latest research in this area. Specifically, we present a rigorous and general theoretical framework as well as an associated, heuristically refined computational methodology that allow not only analysis but also synthesis of a linear control system for a nonlinear process. Application to the multivariable case is presented. Potential future developments within this framework are discussed.
Role of IL-1α in central nervous system immunomodulation of glucoregulation

Abstract Hyperglycemia is a hallmark of the stress response, and has been largely attributed to elevated plasma levels of catabolic hormones. Recently, various cytokines have been shown to be endogenously produced within the brain and may represent an important component of the central regulation of this metabolic response. Therefore, the aim of the present study was to determine whether the intracerebroventricular (i.c.v.) injection of one such peptide, interleukin (IL)-1, can produce hormonal and metabolic alterations comparable to those observed under stress conditions. An i.c.v. cannula and vascular catheters were placed in rats prior to the experiment. Whole body glucose flux was assessed in overnight fasted conscious unrestrained rats using [3-3H]glucose. A mild hyperglycemia was elicited 20 min after the i.c.v. injection of IL-1α (human recombinant, 100 ng) that was not detected in control rats. Glucose levels gradually increased and were 26% higher than control values during the last hour of the 3 h experimental period. The hyperglycemia resulted from a 44% increase in the rate of hepatic glucose output (HGO), which preceded a propertional rise in peripheral glucose utilization. No increase in metabolic clearance rate was observed, suggesting that the increased glucose uptake was the result of mass action. The increased glucose flux was associated with a transient hyperinsulinemia (+95%), and sustained elevations in the arterial concentrations of glucagon (56%) and corticosterone (175%). In contrast, glucose flux was not altered by intravenous administration of the same dose of IL-1α, or i.c.v. injection of IL-1β, or heat-inactivated IL-1α. Indomethacin (5 mg/kg, i.v.) blocked the hyperglycemia and increased HGO induced by i.c.v. injection of prostaglandin E2 (100 ng) produced comparable increases in glucose flux. These results indicate that IL-1α can act centrally to enhance whole body glucose metabolism, and that this response is probably mediated by prostaglandins.
In vitro translation of rabbit lung Clara cell secretory protein mRNA.

Summary The major secretory product of Clara cells is a low molecular weight protein (CCSP) whose extracellular function, at this time, is not known. The primary translation product of its mRNA is a protein with molecular weight approximately 1 kD greater than that of the native secreted protein (6.0 kD). The primary translation product is not detected in incubated lung tissue, only the secretory protein is found. The primary translation product is trypsin sensitive whereas the secretory protein is not. Cell free translation of the mRNA in the presence of microsomes results in cleavage of the signal peptide and the appearance of the lower molecular weight trypsin-resistant secretory protein. These data indicate that the low molecular weight Clara cell secretory protein is synthesized as a larger, trypsin sensitive, protein. Passage of the protein into the cisternae of the endoplasmic reticulum results in loss of the signal peptide and alterations to the tertiary structure of the protein rendering it trypsin insensitive.
A new approach of assessing sagittal discrepancies: the Beta angle

An accurate anteroposterior measurement of jaw relationships is critically important in orthodontic diagnosis and treatment planning. The angular and linear measurements that have been proposed can be inaccurate because they depend on various factors. The purpose of this study was to establish a new cephalometric measurement, named the Beta angle, to assess the sagittal jaw relationship with accuracy and reproducibility. This angle uses 3 skeletal landmarks-point A, point B, and the apparent axis of the condyle-to measure an angle that indicates the severity and the type of skeletal dysplasia in the sagittal dimension. Seventy-six pretreatment cephalometric radiographs of white patients were selected on the basis of 4 criteria that indicate a normal Class I skeletal pattern; the mean and the SD for the Beta angle were calculated. This group was compared with Class II and Class III skeletal pattern groups. After using the 1-way analysis of variance and the Newman-Keuls test and running receiver-operating-characteristics curves, we obtained results that showed that a patient with a Beta angle between 27 degrees and 35 degrees can be considered to have a Class I skeletal pattern. A more acute Beta angle indicates a Class II skeletal pattern, and a more obtuse Beta angle indicates a Class III skeletal pattern.
Catalytic properties of the human cytochrome P450 2E1 produced by cDNA expression in mammalian cells.

Abstract A full-length cDNA encoding human cytochrome P450 2E1 was expressed in mammalian cell lines using the vaccinia virus expression system. Immunoblot analysis showed that the expressed protein reacted with a polyclonal antibody against rat 2E1 and comigrated with P450 2E1 from human liver microsomes. P450 2E1 expressed in Hep G2 cells, a human cell line which contains both cytochrome b5 and NADPH:P450 oxidoreductase, was able to metabolize several known P450 2E1 substrates: N-nitrosodimethylamine (NDMA), N-nitrosomethylbenzylamine (NMBzA), p-nitrophenol, phenol, and acetaminophen. Apparent Km and Vmax values for NDMA demethylation were 22 μ m and 173 pmol/min/mg microsomal protein, respectively. P450 2E1 expressed in TK 143 cells, which do not contain b5, displayed Km and Vmax values of 31 μ m and 34 pmol/min/mg microsomal protein, respectively. Incorporation of purified rat liver b5 into TK−143 microsomes increased the Vmax 2.2-fold and decreased the Km to 22 μ m . Addition of b5 to Hep G2 microsomes resulted in a 1.6-fold increase in Vmax, but showed no effect on the Km. P450 2E1 expressed in Hep G2 cells was shown to metabolize NMBzA with a Km of 47 μ m and Vmax of 213 pmol/min/mg microsomal protein. Addition of b5 lowered the Km to 27 μ m , but had no effect on Vmax. These results demonstrate conclusively that P450 2E1 is responsible for the low Km forms of NDMA demethylase and NMBzA debenzylase observed in liver microsomes and that these activities are affected by cytochrome b5.
A comparison of difficulty and discrimination values of selected true-false item types

Abstract Thirty-eight undergraduate students were randomly assigned one of two alternate forms of a 144-item true-false midterm examination. Whenever a statement appeared on one form as true and positively stated, it appeared on the alternate form as false and negatively stated. Similarly, a false and positively stated item on one form was true and negatively stated on the other. The subject matter of the two forms was identical and the four kinds of true-false items were equally represented on each form. Difficulty and discrimination indices were computed for each of the four item types. The statistical results showed negatively stated items were more difficult, but no more discriminating, than positively stated items. Also, false items were not statistically more difficult than true items, but were significantly more discriminating. It was concluded that test constructors should include more false items than true items in their instruments and that all items should be stated positively.
Compiler-controlled memory

Optimizations aimed at reducing the impact of memory operations on execution speed have long concentrated on improving cache performance. These efforts achieve a. reasonable level of success. The primary limit on the compiler's ability to improve memory behavior is its imperfect knowledge about the run-time behavior of the program. The compiler cannot completely predict runtime access patterns.There is an exception to this rule. During the register allocation phase, the compiler often must insert substantial amounts of spill code; that is, instructions that move values from registers to memory and back again. Because the compiler itself inserts these memory instructions, it has more knowledge about them than other memory operations in the program.Spill-code operations are disjoint from the memory manipulations required by the semantics of the program being compiled, and, indeed, the two can interfere in the cache. This paper proposes a hardware solution to the problem of increased spill costs---a small compiler-controlled memory (CCM) to hold spilled values. This small random-access memory can (and should) be placed in a distinct address space from the main memory hierarchy. The compiler can target spill instructions to use the CCM, moving most compiler-inserted memory traffic out of the pathway to main memory and eliminating any impact that those spill instructions would have on the state of the main memory hierarchy. Such memories already exist on some DSP microprocessors. Our techniques can be applied directly on those chips.This paper presents two compiler-based methods to exploit such a memory, along with experimental results showing that speedups from using CCM may be sizable. It shows that using the register allocation's coloring paradigm to assign spilled values to memory can greatly reduce the amount of memory required by a program.
EM Channel Estimation for Iterative DS-CDMA Receiver using LDPC Codes with M-ary Modulation

This paper proposes an iterative pilot-symbol-aided direct-sequence code-division multiple-access receiver. The receiver uses a regular low-density parity-check (LDPC) code, iterative demodulation and decoding, and iterative estimators for the fading amplitude and noise power spectral density (PSD). The expectation-maximization channel-estimation performance is analyzed for an additive white Gaussian noise channel as well as a Rayleigh fading channel. Pilot symbols are periodically distributed throughout each LDPC codeword followed by direct-sequence spreading and an M-ary modulation, e.g., quadriphase-shift keying. After initial estimates of the fading amplitude and noise PSD are obtained by using pilot information, subsequent values of these parameters are iteratively updated by using the soft feedback from the LDPC decoder. The updated fading amplitude and noise PSD estimates are iteratively passed to the LDPC decoder, which results in decoding performance close to that obtained with perfect channel knowledge.
An infrared spectroscopy study of the molecular structure changes of DNA after electron and ultraviolet irradiation

Samples of calf thymus DNA and two different leukemic leukocyte DNA's in the solid state have been irradiated (at 300°K) with 800 keV electrons and 4.9 eV (2537A) ultraviolet rays. The subsequent effects on the DNA's have been studied using infrared spectroscopy as the probe for radiation-produced molecular alterations. The region of the infrared spectrum studied covered the wave number range from 4000 cm−1 to 300 cm−1. Our results indicate that under electron and ultraviolet irradiation, the prominent infrared active absorption peaks of all three DNA's are altered. The infrared results of our ultraviolet irradiation of DNA indicate that similar molecular bonds are broken as for the case of DNA irradiated with 800 keV electrons. The results indicate that up to high doses, calf thymus DNA is more sensitive to electron irradiation than the leukemic leukocyte DNA's. The infrared active absorption peaks of the two leukemic leukocyte DNA's respond similarly to electrons. The ultraviolet results indicate some difference between calf thymus DNA and the two leukocyte DNA's in their response to 4.9 eV light.
Internal solvation effects on the conformation of acyclics

Abstract Experiments attempting to discern internal solvation (or H—bonding) of COOH or COO− by OH are outlined. In aqueous solutions little evidence for internal solvation exists. In basic methanol this effect appears due to poor solvation by the solvent. The origin of anomalous coupling constants in t-butyl compounds is discussed briefly.
A Treemap Based Method for Rapid Layout of Large Graphs

Abstract graphs or networks are a commonly recurring data type in many fields. In order to visualize such graphs effectively, the graph must be laid out on the screen coherently. Many algorithms exist to do this, but many of these algorithms tend to be very slow when the input graph is large. This paper presents a new approach to the large graph layout problem, which quickly generates an effective layout. This new method proceeds by generating a clustering hierarchy for the graph, applying a treemap to this hierarchy, and finally placing the graph vertices in their associated regions in the treemap. It is ideal for interactive systems where operations such as semantic zooming are to be performed, since most of the work is done in the initial hierarchy calculation, and it takes very little work to recalculate the layout. This method is also valuable in that the resulting layout can be used as the input to an iterative algorithm (e.g., a force directed method), which greatly reduces the number of iterations required to converge to a near optimal layout.
Complexation in the retention of benzoic acids on a bonded xanthine HPLC stationary phase

Abstract The retention of a number of benzoic acids was determined using a bonded xanthine stationary phase (XSP). Retention of benzoate on XSP was studied as a function of pH and organic modifier composition of the mobile phase. The measured retention for 10 substituted benzoic acids was correlated with the complexation constants previously reported for these compounds with theophylline.
Dissection of Quorum-Sensing Genes in Burkholderia glumae Reveals Non-Canonical Regulation and the New Regulatory Gene tofM for Toxoflavin Production

Burkholderia glumae causes bacterial panicle blight of rice and produces major virulence factors, including toxoflavin, under the control of the quorum-sensing (QS) system mediated by the luxI homolog, tofI, and the luxR homolog, tofR. In this study, a series of markerless deletion mutants of B. glumae for tofI and tofR were generated using the suicide vector system, pKKSacB, for comprehensive characterization of the QS system of this pathogen. Consistent with the previous studies by other research groups, ΔtofI and ΔtofR strains of B. glumae did not produce toxoflavin in Luria-Bertani (LB) broth. However, these mutants produced high levels of toxoflavin when grown in a highly dense bacterial inoculum (∼ 1011 CFU/ml) on solid media, including LB agar and King’s B (KB) agar media. The ΔtofI/ΔtofR strain of B. glumae, LSUPB201, also produced toxoflavin on LB agar medium. These results indicate the presence of previously unknown regulatory pathways for the production of toxoflavin that are independent of tofI and/or tofR. Notably, the conserved open reading frame (locus tag: bglu_2g14480) located in the intergenic region between tofI and tofR was found to be essential for the production of toxoflavin by tofI and tofR mutants on solid media. This novel regulatory factor of B. glumae was named tofM after its homolog, rsaM, which was recently identified as a novel negative regulatory gene for the QS system of another rice pathogenic bacterium, Pseudomonas fuscovaginae. The ΔtofM strain of B. glumae, LSUPB286, produced a less amount of toxoflavin and showed attenuated virulence when compared with its wild type parental strain, 336gr-1, suggesting that tofM plays a positive role in toxoflavin production and virulence. In addition, the observed growth defect of the ΔtofI strain, LSUPB145, was restored by 1 µM N-octanoyl homoserine lactone (C8-HSL).
On the Inclusion of Actuator Dynamics in Boundary Control of Distributed Parameter Systems

Abstract The problem of boundary control in systems governed by partial differential equations often leads to abstract control systems of the form where A generates a C 0 -semigroup, B is an unbounded operator and the system is defined in a very weak sense. Here N (·) is a nonlinear term and w p ( t ) represents a disturbance to the plant. In this setting the unboundedness of the operator B can lead to theoretical and computational challenges. However, in most practical settings the input at the boundary v ( t ) is typically the output of a dynamic “actuator” and the inclusion of actuator dynamics is a more realistic representation of the system. Although the inclusion of actuator dynamics can bring additional complexity to the corresponding control problem, in some cases the formulation of the control system as a composite system is essential. Moreover, in some cases including the actuator dynamics can produce theoretical and computational advantages that can be exploited when introducing approximations. In this paper we discuss various formulations of boundary control problems with actuator dynamics and suggest an alternate approach to formulating certain boundary control problems so that the resulting composite system is well-posed. We apply these results to boundary control of parabolic systems to illustrate the ideas and present numerical results.
The economics of acid rain: an invisible hand of control

Economics currently plays an insignificant role in the control of acid rain. Economists have fallen into the old familiar pattern of evaluating the impacts of acid rain instead of developing economic techniques for controlling the source of its emission. Power generating plants and other major producers of acid rain discharge their oxide wastes into the air in order to reduce production costs. This cost saving enables the producer to increase profits and expand production at the expense of those who suffer from acid rain. The solution to this misallocation requires the internalization of all production costs. The price of the product will then reflect its true cost. Acid rain will be eliminated and resources will be more efficiently allocated. Economists will not have to attempt to evaluate the impossible nor trace its untraceable origin. Acid rain will no longer threaten our survival.
Dynamics of Two Strongly Coupled Relaxation Oscillators

This paper concerns the dynamics of a pair of identical, linearly coupled van der Pol relaxation oscillators. We study the stability of the in-phase and out-of-phase modes of vibration. The stability of both modes is shown to be governed by the behavior of a linear Variational equation with periodic coefficients. Approximate analytical solutions are obtained by the method of matched asymptotic expansions. These analytical results are supplemented by numerical integrations based on Floquet theory.It is shown that previous work based on the sinusoidal (nonrelaxation) limit fails to predict a significant region of instability for both modes.
Spectral analysis of a two-species competition model: Determining the effects of extreme conditions on the color of noise generated from simulated time series

Ecologists have observed that environmental noise affects population variance in the logistic equation for one-species growth. Interactions between deterministic and stochastic dynamics in a one-dimensional system result in increased variance in species population density over time. Since natural populations do not live in isolation, the present paper simulates a discrete-time two-species competition model with environmental noise to determine the type of colored population noise generated by extreme conditions in the long-term population dynamics of competing populations. Discrete Fourier analysis is applied to the simulation results and the calculated Hurst exponent (H) is used to determine how the color of population noise for the two species corresponds to extreme conditions in population dynamics. To interpret the biological meaning of the color of noise generated by the two-species model, the paper determines the color of noise generated by three reference models: (1) A two-dimensional discrete-time white noise model (0⩽H <1/2); (2) A two-dimensional fractional Brownian motion model (H=1/2)(H=1/2); and (3) A two-dimensional discrete-time model with noise for unbounded growth of two uncoupled species (1/2<H⩽1).
Discussion of a liquid metal pressure infiltration process to produce metal matrix composites

Abstract The two major processes presently used to manufacture metal matrix composites are solid-state diffusion bonding and squeeze casting. The former has shape limitations; it is suitable to produce only flat plates or sheets, and the manufacturing rate is low and expensive. The latter, although suitable for quantity production of complex shapes, requires heavy and expensive tooling. The described pressure infiltration process was developed at Massachusetts Institute of Technology. With this process, fiber, whisker or particulate pre-forms are placed in inexpensive throw-away containers, into which the molten matrix material is forced by gas pressure. Because the gas pressure on the pre-form container is quasi hydrostatic, its strength requirement is minimal, consequently pre-form containers, even those with complicated shapes, are easy to preprare. By virtue of the simplicity of the containers and the absence of the requirement of a heavy mechanical system to effect the infiltration of the liquid metal into the pre-forms, the process is suitable to produce bulk or final-shape composite parts inexpensively. As the processing parameters such as pre-form temperature, infiltrating metal temperature, infiltrating pressure and cooling rate, can be accurately controlled, the process is particularly suitable for research and limited production.
Hebephilia: A Postmortem Dissection.

In 2008, the concept of hebephilia, which denotes an erotic preference for “pubescent children,” was suggested by Blanchard and his team for inclusion in the DSM-5 (Blanchard et al., 2009). Four years later, the APA’s Board of Trustees opted for the status quo and rejected that proposal. This essay sheds light on the reason for this rejection. I consider three important questions related to hebephilia: Does hebephilia exist? Is it a disease? And what would have been the social consequences of including it in the DSM? I argue that if Blanchard failed to convince others that hebephilia should be included in the DSM-5, it is not because he focused too much on the first question and was unable to offer a convincing answer to the second one, but because he made the mistake of dismissing the third one as extraneous. The DSM is not intended to be a pure research manual, and a category like hebephilia cannot be evaluated without taking into account its potential forensic impact. In part or in whole, the decision to include a new diagnostic category in the DSM is, and always should be, a political decision.
Advocacy for Child Wellness in High-Poverty Environments

AbstractChild wellness needs to be understood holistically so that children and youth from high-poverty environments can succeed in schooling and life. Teachers who foster advocacy in themselves are well equipped to teach students to take ownership of their own well-being. Such advocacy can enrich the classroom curriculum and mitigate the negative effects of disadvantaged environments and segregated educational systems.
Injuries sustained during competitive white-water paddling: a survey of athletes in the 1996 Olympic trials

To examine injury prevalence in competitive paddlers, a cross-sectional, retrospective, written survey of the athletes competing in the four regional Olympic canoe and kayak qualifying races for the United States Canoe and Kayak Team was conducted in the spring of 1996. A total of 375 questionnaires were distributed, of which 54 were completed and returned. Results were reported as the percentage of total injuries. A composite of 271 separate injuries was reported by kayakers during their careers. While 56% of the injuries occurred during training, 40% happened during recreation and 4% during competition. The most frequent injuries were sprains (32%), tendonitis (20%), and chronic musculoskeletal pain (14%). Simple bruises (9%) and infections (8%) occurred with moderate frequency, while severe injuries, such as dislocations (3%) and lacerations (2%), were even less common. About 10% of the paddlers noted a near-drowning event during their careers. Of the injuries noted, 70% were reported as recurrent or chronic. Treatment included rest (37%), physical therapy (23%), medical intervention (34%), and surgical intervention (6%). White-water paddling of canoes and kayaks is a potentially dangerous sport, and competitive paddlers frequently suffer a range of injuries. Most injuries occurred during training; however, the short intense work of racing produced a greater frequency of injuries.
Deformation mechanisms in Ti-6Al-4V/TiC composites

The compressive behavior at room temperature of Ti-6Al-4V/TiC composites was examined at strain rates from 0.1 to 1000 s−1. As little as 1 vol pct TiC particulates provided greater than a 20 pct increase in strength over that of the monolithic Ti-6Al-4V, while further additions of TiC did not provide proportional benefits. Microstructural examination before and after compression testing was instrumental in understanding the relative importance of the primary strengthening mechanism in the composites as compared to the monolithic material. A comparison of the various possible mechanisms clearly showed that the dominant mechanism was due to carbon in solid solution. At low strain rates, the failure process consisted of a progression of damage in the matrix and at particle-matrix boundaries, while at high strain rates, failure occurred along adiabatic shear bands. The composites had a greater susceptibility to adiabatic shear-band formation than did the monolithic material.
Imitations and repetitions: what do children say following recasts?

The current study investigated whether children revise their speech (i.e., imitate) or repeat their errors following negative evidence. In addition we examined how children's replies varied as a fu...
Perceptions of Risk Factors for School Violence: Concordance with FBI Risk Profile.

The Federal Bureau of Investigation (FBI, 2000) recently released a report on common background characteristics of school shooters, which also stressed the importance of evaluating the reality of threat. The present study evaluated respondents' ability to discriminate between an unrealistic and a realistic threat and between a low and high risk level based on the FBI's background profile characteristics as well as to determine attitudes about whether some intervention was necessary. Respondents completed one of four randomly distributed vignettes, which differed in a 2 X 2 design (high vs. low background risk X realistic vs. unrealistic threat). These vignettes described a student who made a threatening statement regarding a teacher. Respondents then rated the student's level of risk for violence and indicated the degree to which they would intervene. Results revealed that, in keeping with the FBI guidelines, both reality of threat and background risk characteristics significantly influenced respondents' perceived risk for violence and need to intervene. Implications for educational settings and future research are discussed. Language: en
The end of the road

After some 60 years in research, a few months before my final retirement (there were a few temporary ones), the time has come to reminisce.
Low somatomedin activity in cord serum from infants with intrauterine growth retardation

Somatomedin activity was determined by the simultaneous incorporation of 35 S-sulfate and 3 H-methyl thymidine into costal cartilage from hypophysectomized rats in cord sera from term and preterm infants and infants with intrauterine growth retardation. Mean Sm activity by sulfate incorporation was 0.49±0.04, 0.35±0.05, and 0.09±0.03 units/ml (±SE) in the term, preterm, and IGR cord sera, respectively. The levels for each group were significantly different from each of the other groups. There was no significant difference between the mean Sm activity by thymidine incorporation in cord sera from term (0.92±0.09 units/ml) and preterm (0.87±0.08 units/ml) infants. These levels were significantly higher, however, than the Sm activity by sulfate incorporation for the respective groups, P P
Cranial allometry and geographic variation in slow lorises (Nycticebus)

A series of 20 craniodental measurements was obtained for two sister taxa: Nycticebus coucang (common slow loris) and N. pygmaeus (pygmy slow loris). Multivariate analysis of variance was performed with adult data to describe patterns of subspecific and specific variation in this genus. The geometric mean of adult cranial dimensions was compared to field data on latitudinal coordinates for available specimens to investigate if size variation in Nycticebus is clinal in nature. Ontogenetic series for larger-bodied N. coucang and smaller-bodied N. pygmaeus were compared to test the hypothesis that species and subspecific variation in skull form results from the differential extension of common patterns of relative growth. A MANOVA provides independent support of Groves's [pp. 44–53 in Proceedings of the Third International Congress on Primatology, Vol. 1 (Basel: S. Karger), 1971] classification of Nycticebus into two species, with four subspecies in the common slow loris and one form of the pygmy slow loris. Within N. coucang, cranial proportions for all four subspecies are ontogenetically scaled, and size differentiation is mainly clinal (Bergmann's Rule). N. c. bengalensis represents the most northerly disposed and the largest form. N. c. javanicus represents the next-largest form and is located in a southerly direction the next-farthest away from the equator. N. c. coucang and N. c. menagensis are both equatorial; however, the latter subspecies is the smallest. A genetic basis for some of the taxonomic variation between N. c. coucang and N. c. menagensis is supported by such nonclinal variation in body size. Variation in the presence/absence of I2 is not size-related but rather tracks geographic proximity and isolating factors which predate the most recent inundation of the Sunda Shelf. Although they inhabit a nonequatorial environment, pygmy slow lorises are the smallest of all Nycticebus. As N. pygmaeus is sympatric with N. c. bengalensis, the largest slow loris, it appears that the evolution of its smaller body size represents a case of character displacement. Unlike N. coucang, skull size becomes significantly smaller in more northern N. pygmaeus. This may also reflect character displacement between sympatric sister taxa underlain by a cline-dependent ecological factor which is marked in more northerly latitudes. On the other hand, the negative correlation between body size and latitude in N. pygmaeus could be due to the influence of nonprimate fauna, such as predators, which themselves evince a similar clinal pattern. Analyses of relative growth indicate that skull proportions in the two species of Nycticebus are ontogenetically scaled in two-thirds of the cases. All but one of the seven comparisons (interorbital breadth) which do not indicate ontogenetic scaling represent part of the masticatory complex. This likely reflects a reorganization of N. pygmaeus maxillomandibular proportions linked to smaller size and changes in diet. Am. J. Primatol. 45:225–243, 1998. © 1998 Wiley-Liss, Inc.
The involvement of cyclic AMP-dependent protein kinase(s) in the induction of ornithine decarboxylase in the regenerating rat liver and in the adrenal gland after unilateral adrenalectomy.

Abstract We investigated the temporal relationship between the level of cyclic AMP, the activation of cyclic AMP-dependent protein kinase(s), and the induction of ornithine decarboxylase in two important rapid growth systems: the regenerating rat liver and the remaining adrenal gland following unilateral adrenalectomy. There was a biphasic increase in the aactivity of ornithine decarboxylase at 4 and 14 h following partial hepatectomy. The concentration of cyclic AMP increased 2-fold compared to sham-operated animals within 2–3 h, returned to baseline by 8 h, and was elevated again 3-fold by 12 hours. The activation of cyclic AMP-dependent protein kinase(s) occured in a similar biphasic manner. From a control activity ratio (−cAMP/+cAMP) of 0.4, values for total soluble kinase activation reached 0.75 at both 2 and 14 h. After a delay of 2 h following unilateral adrenalectomy, ornithine decarboxylase activity in the remaining adrenal gland increased 15–20-fold of control level by 8 h. Cyclic AMP concentrations in the adrenal were elevated 3.5-fold within 30 min. The protein kinase activation increased from 0.25 to nearly a totally activated state of 1.0 within 1 h, decline to 0.4 by 2 h, and returned to the level of the sham-operated controls at 8 h. In both the rat liver in response to partial hepatectomy and the adrenal gland undergoing hypertrophy, cyclic AMP-dependent protein kinase(s) was markedly activated prior to increases in ornithine decarboxylase activity.
Finite Element Simulation of Ausforming of Austempered Ductile Iron Components

The mechanical properties of ductile iron can be improved by ausforming, that is, applying work during austempering. The resulting yield strength and ductility are comparable to those of SAE 4140 steel, while the density is approximately 10 percent less. The viability of manufacturing components by casting a preform, austenitizing it, quenching it to the austempering temperature, forging it, austempering it, and finally, quenching it to the net shape is investigated by simulating the forging operation with finite element analysis. The preform geometry and die set geometry are determined such that the forging operation imparts a reasonably uniform equivalent plastic strain of 20 percent to the workpiece and the prescribed final component geometry is obtained. Forging of two components of varying geometric complexity is simulated using a commercial software package. The results indicate that the geometry of the final part is reasonably close to the goal and that the equivalent plastic strain distribution is reasonably uniform-over 80 percent of the material was plastically deformed 15-25 percent. The design of the preform and die sets appears to be an excellent application for an optimization algorithm.
Spiny neurons of amygdala, striatum, and cortex use dendritic plateau potentials to detect network UP states.

Spiny neurons of amygdala, striatum, and cerebral cortex share four interesting features: [1] they are the most abundant cell type within their respective brain area, [2] covered by thousands of thorny protrusions (dendritic spines), [3] possess high levels of dendritic NMDA conductances, and [4] experience sustained somatic depolarizations in vivo and in vitro (UP states). In all spiny neurons of the forebrain, adequate glutamatergic inputs generate dendritic plateau potentials (“dendritic UP states”) characterized by (i) fast rise, (ii) plateau phase lasting several hundred milliseconds and (iii) abrupt decline at the end of the plateau phase. The dendritic plateau potential propagates towards the cell body decrementally to induce a long-lasting (longer than 100 ms, most often 200 – 800 ms) steady depolarization (~20 mV amplitude), which resembles a neuronal UP state. Based on voltage-sensitive dye imaging, the plateau depolarization in the soma is precisely time-locked to the regenerative plateau potential taking place in the dendrite. The somatic plateau rises after the onset of the dendritic voltage transient and collapses with the breakdown of the dendritic plateau depolarization. We hypothesize that neuronal UP states in vivo reflect the occurrence of dendritic plateau potentials (dendritic UP states). We propose that the somatic voltage waveform during a neuronal UP state is determined by dendritic plateau potentials. A mammalian spiny neuron uses dendritic plateau potentials to detect and transform coherent network activity into a ubiquitous neuronal UP state. The biophysical properties of dendritic plateau potentials allow neurons to quickly attune to the ongoing network activity, as well as secure the stable amplitudes of successive UP states.
The Demand for Engineers-Projections Through 1987

Engineering manpower constitutes an important national resource where demand and supply must be in reasonable balance to assure continued economic growth. The paper establishes a demand analysis to predict the need for engineers in 15 industry groups through 1987, subject to various economic scenarios. It is shown that for total engineering employment in any industry segment the constant dollar gross national product fraction per engineer is only a slowly varying function of time. A least-square fit of this ratio versus time is shown to be an adequate predictor of employment and can be used for extrapolation with confidence. A parallel analysis is also developed for engineers employed in research and development. It is shown that, in general, the need for new engineers due to economic growth is smaller than the need to make up for attrition due to death, retirement, promotions out of engineering and voluntary leaving of the profession. The high mobility rate of engineers out of the profession is significant and its importance has not previously been documented. The paper concludes with a preliminary discussion of the balance between supply and demand. Even with a healthy economic growth the nation is likely to produce a small excess of engineering graduates over the near future. However, there will be a shortage of engineers holding advanced degrees for entry into research and development, even if R&D sees only a moderate growth. Better industry-university cooperation is called for to encourage engineers to undertake advanced degrees, to assess actual future needs and to advise students to select appropriate engineering disciplines.
Comparison of Midazolam and Diazepam by the Intramuscular Route for the Control of Seizures in a Mouse Model of Status Epilepticus

A model system is described in which sustained clonic seizures are produced by a combination of phenytoin (PHT) and pentylenetetrazol (PTZ) in the mouse, the former agent preventing the terminal tonic spasms produced by the latter. In this system, midazolam (MDL), a water-soluble benzodiazepine, was compared with diazepam (DZP), a sparingly soluble agent which is widely used to treat status epilepticus (SE) in humans. Both agents were administered intramuscularly (i.m.) in approximately equieffective doses in animals exhibiting clonic seizure activity. MDL proved to be about twice as potent as DZP. Whereas control animals convulsed for a period of approximately 90 min, those treated with DZP 0.2 and 0.4 mg/kg convulsed for 7.8 and 3.9 min, respectively; mice receiving MDL 0.1 and 0.2 mg/kg convulsed for 1.9 and 1.4 min, respectively. MDL arrested seizures substantially more rapidly than diazepam (p less than 0.05). These data suggest that MDL has sufficiently rapid anticonvulsant action to merit evaluation for control of SE in humans when a rapidly absorbed antiepileptic drug (AED) is needed and intravenous (i.v.) administration is not feasible.
Enhanced charge separation in organic photovoltaic films doped with ferroelectric dipoles

A key requirement for realizing efficient organic photovoltaic (OPV) cells is the dissociation of photogenerated electron-hole pairs (singlet-excitons) in the donor polymer, and charge-transfer-excitons at the donor–acceptor interface. However, in modern OPVs, these excitons are typically not sufficiently harnessed due to their high binding energy. Here, we show that doping the OPV active-layers with a ferroelectric polymer leads to localized enhancements of electric field, which in turn leads to more efficient dissociation of singlet-excitons and charge-transfer-excitons. Bulk-heterojunction OPVs based on poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester are fabricated. Upon incorporating a ferroelectric polymer as additive in the active-layer, power conversion efficiencies increase by nearly 50%, and internal quantum efficiencies approach 100% – indicating complete exciton dissociation at certain photon energies. Similar enhancements in bilayer-heterojunctions, and direct influence of ferroelectric poling on device behavior show that improved dissociation is due to ferroelectric dipoles rather than any morphological change. Enhanced singlet-exciton dissociation is also revealed by photoluminescence lifetime measurements, and predicted by simulations using a numerical device model.
Imaging of pseudoneoplastic masses associated with allografts

Objective The objective of this study is to describe the imaging features of non-neoplastic masses suspected of being tumor recurrences adjacent to allografts. The allografts were utilized for the treatment of various musculoskeletal tumors.
Expression and steroid hormonal control of muc-1 in the mouse uterus

Previous studies from our laboratory established that large M(r) mucin glycoproteins are major apically disposed components of mouse uterine epithelial cells in vitro. The present studies demonstrate that Muc-1 represents one of the apically disposed mucin glycoproteins of mouse uterine epithelia, and that Muc-1 protein and messenger RNA (mRNA) expression are regulated in the periimplantation mouse uterus by ovarian steroids. Muc-1 expression is exclusive to the epithelial cells of the uterus under all conditions examined. Muc-1 expression is high in the proestrous and estrous stages and decreases during diestrous. Both Muc-1 protein and mRNA decline to barely detectable levels by day 4 of pregnancy, i.e. before the time of blastocyst attachment. In contrast, Muc-1 expression in the cervix and vagina is maintained during this same period. Delayed implantation was established in pregnant mice by ovariectomy and maintained by the administration of exogenous progesterone (P). Initiation of implantation was triggered by coinjection of P-maintained mice with a nidatory dose of 17 beta-estradiol (E2). Muc-1 levels in the uterine epithelia of P-maintained mice declined to low levels similar to those observed on day 4 of normal pregnancy. Coinjection of E2 did not alter Muc-1 expression, suggesting that down-regulation of Muc-1 is a P-dominated event. This was confirmed in ovariectomized nonpregnant mice, which displayed stimulation of Muc-1 expression after 6 h of E2 injection. E2-Stimulated Muc-1 expression was inhibited by the pure antiestrogen, ICI 164,384. Although P alone had no effect on Muc-1 expression, it antagonized the action of E2. Injection of pregnant mice with the antiprogestin, RU486, a known implantation inhibitor, on day 3 of pregnancy restored high level expression of Muc-1 mRNA on day 4, indicating that down-regulation of Muc-1 is P receptor mediated. Collectively, these data indicate that Muc-1 expression in mouse uterine epithelium is strongly influenced by ovarian steroids. It is suggested that the loss of Muc-1 contributes to generation of a receptive uterine state.
A critique of cross-lagged correlation

Comments that cross-lagged correlation (CLC) is not a useful procedure for the analysis of longitudinal panel data. In particular, the difference between CLCs is not a sound basis for causal inference. Demonstrations of the failure of CLC are based mainly on results for the 2-wave, 2-variable longit
Induced 4D self-dual quantum gravity: W algebraic approach

The authors consider the functional integral quantization of the equation which describes a development of cross sections in a twistor space corresponding to self-dual gravity. At the classical level the system permits a local area-preserving diffeomorphism as its symmetry. Assuming Winfinity algebra at the quantized level, they derive an effective action for this equation via the coadjoint orbit method. The result consists of an infinite sum of two-dimensional effective Lagrangians including infinitesimal Polyakov two-dimensional (light-cone gauge) gravity as its first term. The higher order terms are the result of the central extensions of Winfinity algebra associated with higher conformal-spin operators.
Multistage risk models and the age pattern in familial polyposis coli.

AbstractMultistage risk models provide a close fit to most age patterns of adult-onset cancers. Such models posit that a number of events must occur before some cell in a tissue is transformed from normal to neoplastic. When an approximate version of the models has been fitted to data, this number has been estimated to be about 4–6. In fitting the same approximate model to the age pattern of onset of colon cancer in bearers of the Familial Polyposis coli (FPC) gene, several authors have found that the number of stages estimated was about two to three fewer than those for colon cancer in the general population. However, when an exact multistage model is used rather than an approximation to it, this is no longer the case: the number of stages estimated from the general population becomes too large to be compatible with what is known about carcinogenesis from laboratory experiments, and the number estimated from FPC victims is larger than that for the general population.“Inherited-hit” models of the nature o...
Laminar natural convection heat transfer in ellis fluids

An approximate solution for the problem of determining the laminar natural convection heat transfer between a vertical flat surface and a fluid whose rheological behavior is characterized by Ellis' model is found using an integral method. The results are in reasonable agreement with available experimental data. The choice of the rheological model to be used in describing and correlating natural convection phenomena in non-Newtonian fluids is discussed.