cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization and bioactive properties of zirconia based polymeric hybrid for orthopedic applications

Zirconia is a transition metal oxide with current applications to orthopedic implants. It has been shown to up-regulate specific genes involved in bio-integration and injury repair. This study examines the effects of zirconia and polydimethylsiloxane (PDMS) hybrids on the proliferation and viability of human primary osteoblast and fibroblast cells. In this study, zirconia–PDMS hybrid coatings were synthesized using a modified sol gel process. The hybrid material was characterized using optical microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and contact angle analysis. This study demonstrates that Zr–PMDS surface materials display hydrophobic surface properties coupled with a preferential deposition of polymer near the surface. Primary osteoblast and fibroblast proliferation and viability on hybrid coated surfaces were evaluated via a rapid screening methodology using WST-1 and calcein AM assays. The cells were seed at 5,000 cells per well in 96-well plates coated with various composition of Zr–PDMS hybrids. The results showed increasing cell proliferation with increasing zirconia concentration, which peaked at 90 % v/v zirconia. Proliferation of osteoblasts and fibroblasts displayed similar trends on the hybrid material, although osteoblasts displayed a bi-phasic dose response by the calcein AM assay. The results of this current study show that Zr–PDMS may be used to influence tissue–implant integration, supporting the use of the hybrid as a promising coating for orthopedic trauma implants.
Regional control of histone H3 lysine 27 methylation in Neurospora

Trimethylated lysine 27 on histone H3 (H3K27me3) is present in Drosophila, Arabidopsis, worms, and mammals, but is absent from yeasts that have been examined. We identified and analyzed H3K27me3 in the filamentous fungus Neurospora crassa and in other Neurospora species. H3K27me3 covers 6.8% of the N. crassa genome, encompassing 223 domains, including 774 genes, all of which are transcriptionally silent. N. crassa H3K27me3-marked genes are less conserved than unmarked genes and only ∼35% of genes marked by H3K27me3 in N. crassa are also H3K27me3-marked in Neurospora discreta and Neurospora tetrasperma. We found that three components of the Neurospora Polycomb repressive complex 2 (PRC2)—[Su-(var)3–9; E(z); Trithorax] (SET)-7, embryonic ectoderm development (EED), and SU(Z)12 (suppressor of zeste12)—are required for H3K27me3, whereas the fourth component, Neurospora protein 55 (an N. crassa homolog of p55/RbAp48), is critical for H3K27me3 only at subtelomeric domains. Loss of H3K27me3, caused by deletion of the gene encoding the catalytic PRC2 subunit, set-7, resulted in up-regulation of 130 genes, including genes in both H3K27me3-marked and unmarked regions.
The Climate Change Commitment

Even if atmospheric composition were fixed today, global-mean temperature and sea level rise would continue due to oceanic thermal inertia. These constant-composition (CC) commitments and their uncertainties are quantified. Constant-emissions (CE) commitments are also considered. The CC warming commitment could exceed 1°C. The CE warming commitment is 2° to 6°C by the year 2400. For sea level rise, the CC commitment is 10 centimeters per century (extreme range approximately 1 to 30 centimeters per century) and the CE commitment is 25 centimeters per century (7 to 50 centimeters per century). Avoiding these changes requires, eventually, a reduction in emissions to substantially below present levels. For sea level rise, a substantial long-term commitment may be impossible to avoid.
An innovation-focused roadmap for a sustainable global photovoltaic industry

The solar photovoltaic (PV) industry has undergone a dramatic evolution over the past decade, growing at an average rate of 48 percent per year to a global market size of 31 GW in 2012, and with the price of crystalline-silicon PV module as low as $0.72/W in September 2013. To examine this evolution we built a comprehensive dataset from 2000 to 2012 for the PV industries in the United States, China, Japan, and Germany, which we used to develop a model to explain the dynamics among innovation, manufacturing, and market. A two-factor learning curve model is constructed to make explicit the effect of innovation from economies of scale. The past explosive growth has resulted in an oversupply problem, which is undermining the effectiveness of “demand-pull” policies that could otherwise spur innovation. To strengthen the industry we find that a policy shift is needed to balance the excitement and focus on market forces with a larger commitment to research and development funding. We use this work to form a set of recommendations and a roadmap that will enable a next wave of innovation and thus sustainable growth of the PV industry into a mainstay of the global energy economy.
Design and Validation of Fault Diagnoser Based on Finite State Automaton and Sequential Function Chart for PLC Based Manufacturing System

In ISFA-2010, we proposed a fault diagnoser design based on finite state automaton and sequential function chart to diagnose programmable logic controller (PLC) based manufacturing systems. A deficiency for that paper is that it only laid down a theoretical framework but lacking a detailed implementation and experiment validation. This paper aims at remedying the deficiency with detailed system design to diagnose discrete event system (DES) faults. Systematic diagnosis approach including modeling the plant, mapping output states with sensor readings, and designing diagnoser, was illustrated in this paper. The proposed diagnoser was implemented using Visual Basic to diagnose typical faults a PLC controlled dual robot arm. Experiment validation illustrated that the proposed diagnoser can detect and isolate DES equipment faults with a high fault detection rate of 93%, and detection rate of 80% when including product tolerance fault. The proposed diagnoser can achieve maximum fault detection delay of 9 seconds on the equipment faults. For the future direction, we are planning to extend the proposed diagnoser design to detect probabilistic faults in PLC based automated systems.Copyright © 2012 by ASME
Combined Atlantoaxial Rotatory Fixation and Unilateral Counter Occipitoatlantal Subluxation after Minor Trauma

Rotatory deformities of the atlantoaxial joint may becaused by trauma, upper respiratory tract infection, juvenile rheumatoid arthritis, congenital condition (Down’s syndrome, Marfan’s syndrome). Although most of them are reduced spontaneously or with traction, in rare cases, they may persist. To describe such persistent rotation, Wortzman and Dewar in 1968 used the term, rotary fixation of the atlantoaxial joint. In 1977 Fielding and Hawkins used the term, atlantoaxial rotatory fixation (AARF), because the fixation of the atlas on the axis may occur with subluxation or dislocation. Although AARF in children may be a well-documented, combined AARF and occipitoatlantal subluxation is a rare disease. Patients with combined AARF and occipitoatlantal subluxation has less rotated and tilted head than those with AARF only, because of counter occipitoatlantal subluxation. So it is often difficult to diagnosis accurately. We report a case of combined AARF and unilateral counter occipitoatlantal subluxation after minor trauma. Case Report
Clinical application of CNS-acting agents in FSD

ABSTRACT Introduction Human sexual response involves a complex sequencing of interrelated mind/body processes. Few treatment options exist that address the complex multilayered etiological determinants of female sexual dysfunction (FSD). Aim Review and evaluate the clinical application of centrally acting agents for the treatment of FSD, with particular emphasis on recently released data on bremelanotide. Methods Review of literature on the treatment of FSD. Results Approaches to FSD treatment have ranged from psychological counseling through a variety of medical interventions along the physiological pathways of sexual function and dysfunction. Despite a great deal of research, especially into hormonal and vasoactive substances, few therapeutics have broad consistent applicability and have withstood scientific scrutiny. Recent clinical trials have investigated the potential role of agents which act on the central nervous system for the treatment of FSD. Conclusions While the recent data supporting the therapeutic use of centrally acting agents as a monotherapy for FSD are cautiously encouraging, there would seem to be tremendous promise for these centrally acting compounds to be integrated with treatment approaches that utilize other pathways in a multilayered, individualized approach to care. Perelman MA. Clinical application of CNS-acting agents in FSD.
Telomere-end processing: The terminal nucleotidesof human chromosomes

Mammalian telomeres end in single-stranded, G-rich 3' overhangs resulting from both the "end-replication problem" (the inability of DNA polymerase to replicate the very end of the telomeres) and postreplication processing. Telomeric G-rich overhangs are precisely defined in ciliates; the length and the terminal nucleotides are fixed. Human telomeres have very long overhangs that are heterogeneous in size (35-600 nt), indicating that their processing must differ in some respects from model organisms. We developed telomere-end ligation protocols that allowed us to identify the terminal nucleotides of both the C-rich and the G-rich telomere strands. Up to approximately 80% of the C-rich strands terminate in CCAATC-5', suggesting that after replication a nuclease with high specificity or constrained action acts on the C strand. In contrast, the G-terminal nucleotide was less precise than Tetrahymena and Euplotes but still had a bias that changed as a function of telomerase expression.
Synthetic peptide analogs to barnacle settlement pheromone.

Abstract Barnacle pheromone enhances the rate of settlement and metamorphosis of larvae of Balanus amphitrite Darwin. Analogs to the heterogeneous pheromone peptides were sought. Settlement assays were used to assess both the pheromone and the potential analogs. The pheromone has a lower threshold of activity at a concentration of 0.2 μg BSA protein equivalence l −1 . Treatment with carboxypeptidase eliminates biological activity. Series of dipeptides were tested to determine if dipeptides could promote settlement. Combinations of acidic, neutral, and basic amino acids in dipeptides were examined. Specific small peptides can mimic barnacle pheromone. Only peptides with a basic carboxy-terminal amino acid and either a neutral or a basic amino-terminal amino acid enhance settlement. Six peptides were shown to mimic pheromone activity at concentrations comparable to the native molecule. Some peptides were more potent than others. The most effective peptides were L-leucyl-L-arginine and L-histidyl-L-lysine which had a lower threshold of settlement enhancement of 2.0×10 −10 M and caused a 130% increase in settlement rate at 2.0×10 −8 M. Glycyl-glycyl-L-arginine, glycyl-L-histidyl-L-lysine, L-leucyl-glycyl-L-arginine and L-tyrosyl-L-arginine had thresholds between 2.0×10 −8 M and 2.0×10 −9 M. Peptide pheromone analogs should be useful in determining the nature and mechanism of barnacle pheromone receptor interactions.
FRUITS AND SEEDS OF THE BRANDON LIGNITE III. TURPINIA (STAPHYLEACEAE)

Turpinia uliginosa sp. nov. is described as seeds from the Early Oligocene Brandon Lignite. This occurrence represents a considerable departure from its modern range in the Old and New World tropics. A survey of the previously described fossil seeds and seeds of the modern species suggests thatTurpinia uliginosa is most closely related to the Neotropical members of the modern genus. A brief summary is offered of the characters of the modern seeds ofStaphylea andTurpinia.
Analysis of Liquid and Structural Transients in Piping by the Method of Characteristics

Since liquid-filled piping systems are composed of slender elements, their transient behavior can be described as one-dimensional wave phenomena. Seven wave com­ ponents are identified: coupled axial compression of liquid and pipe material; coupled transverse shear and bending of the pipe elements in two principal direc­ tions; and torsion of the pipe wall. Utilizing the method of characteristics, the com­ bined system of difference equations for pipe elements and the pipe junction boun­ dary conditions comprise a general mathematical tool for predicting the liquid pressure and pipe stress responses to transient excitation of either liquid or piping. The complexity of fluid-structure interaction that can take place is demonstrated.
Absence of correlation between symptoms and rhythm in "symptomatic" atrial fibrillation.

Background Symptoms are widely used as a means of assessment and follow-up of patients with atrial fibrillation. This study assessed the correlation between symptoms and cardiac rhythm in patients being evaluated for operative therapy for atrial fibrillation. Methods Seven days of preoperative continuous outpatient home electrocardiographic monitoring was performed on 50 patients with symptomatic atrial fibrillation. Cardiac rhythm was continuously monitored automatically, while patients recorded their symptoms electronically. Correlations were then drawn between symptomatic events and actual rhythm, and between atrial fibrillation episodes and symptoms. Results Fifty patients (37 men) with symptomatic atrial fibrillation were monitored for a combined 356 days (mean, 7.1 days). Patients were average age of 69 years old. Intermittent atrial fibrillation was reported by 36 patients, and 14 believed their atrial fibrillation was continuous. During monitoring, all patients had periods of both atrial fibrillation and normal sinus rhythm. Of the 552 documented episodes of atrial fibrillation, 467 (85%) were asymptomatic, and 85 (15%) episodes were symptomatic. Patients indicated that they experienced atrial fibrillation symptoms 163 times. Of the 163 symptomatic events, 85 (52%) were actual atrial fibrillation, 64 (42%) were sinus rhythm, and 14 (6%) were other rhythms. The ability of an individual patient to accurately identify atrial fibrillation ranged from 0% to 100%. Conclusions Patient-reported symptoms of atrial fibrillation had poor correlation with actual rhythm. The lack of correlation between symptoms and rhythm underscores the importance of continuous home monitoring for accurately quantifying preoperative atrial fibrillation burden and for postoperative follow-up.
Stratum-Specific Expression of Human Transferrin Receptor Increases Iron in Mouse Epidermis

Epidermal desquamation accounts for 20% of the body's iron loss each day. Yet, little is known about how iron content in epidermis is regulated. To test the importance of the transferrin receptor in regulating iron content in epidermis, we created transgenic mice that have stratum-specific expression of the human transferrin receptor. The keratin 14 promoter targeted the receptor primarily to basal, proliferating keratinocytes; the involucrin (Inv) promoter targeted the receptor to suprabasal, differentiating keratinocytes. There were age- and site-dependent differences in iron content in the epidermis and hair. In both types of transgenic mice, epidermal iron content increased with age and at 8 weeks was 2-3-fold greater in transgenic mice compared to littermate controls. Iron was increased up to 2-fold in hair of keratin 14-human transferrin receptor (hTfR) transgenics and 30% in Inv-hTfR transgenics. No gross or histological changes were seen in transgenic animals with increased iron in the epidermis. Ferritin expression, which was low in normal epidermis, was greatly increased in both transgenic lines, indicating that it is the likely depot for the extra iron in these animals. These data show that control of transferrin receptor expression is sufficient to regulate iron content in proliferating or differentiating keratinocytes in the epidermis.
An equivalence classes model of fuzzy relational databases

Abstract The technique of employing sets of values for tuple components to express imprecision in relational databases was proposed by Buckles and Petry in their classic works on fuzzy relational databases. In addition to providing an intuitively appealing scheme for representing fuzzy information, the model of Buckles and Petry possesses several key properties of the classical relational model. By employing finite scalar domains with similarity relations and special fuzzy number domains, Buckles and Petry have demonstrated that the classical properties of uniqueness of tuple interpretations and well-definedness of the relational algebra can be retained in the fuzzy relational database model. The key to the preservation of these properties is the fact that scalar domains with similarity relations and the fuzzy number domains can be partitioned into equivalence classes. However, since equivalence classes can be constructed without assuming the existence of similarity relations or special fuzzy number domains, it is desirable to generalize the fuzzy relational database model to one based only on equivalence classes. In this work we show that the important properties of classical relational databases (and of fuzzy relational databases) are preserved in a generalized model built on equivalence relations on finite database domains. Further, we generalize the notion of a functional dependency to the fuzzy relational model.
Transfusion Reactions Associated with Anti‐IgA Antibodies: Report of Four Cases and Review of the Literature

Four cases of anaphylactic and anaphylactoid transfusion reactions associated with anti-IgA antibodies are reported. Two were class-specific and two were of limited specificity. All four patients had serious reactions characterized by hypotension, dyspnea, flushing of face and neck, or erythematous rash after administration of otherwise compatible blood. In one patient this reaction was fatal. In another, diagnosis of the condition based on previous transfusion history prevented a subsequent reaction. Review of the literature reveals an apparently low incidence of reactions but a relatively large susceptible population with anti-IgA. Reported reactions have occurred equally in both sexes and largely in patients over 40 years of age who previously have been transfused or pregnant. Although severe and dramatic, these reactions have responded well to treatment and generally have not had serious sequelae.
WSN-based real-time data collection in independent living spaces

Collecting and analyzing real-time data of a distributed wireless sensor network system is very challenging since it combines a series of processes to continuously monitor and respond to a wide variety of events. This paper presents an event-driven, real-time data collection system architecture for an independent living spaces monitoring system. A service-replacement-based timestamp matching structure is also proposed to improve the system's robustness and maintainability. A prototype system has been developed to validate the proposed approach.
The Role of Structural Dynamics and Testing in the Shuttle Flowliner Crack Investigation

During a normal inspection of the main propulsion system at Kennedy Space Center, small cracks were noticed near a slotted region of a gimbal joint flowliner located just upstream from one of the Space Shuttle Main Engines (SSME). These small cracks sparked an investigation of the entire Space Shuttle fleet main propulsion feedlines. The investigation was initiated to determine the cause of the small cracks and a repair method that would be needed to return the Shuttle fleet back to operation safely. The cracks were found to be initiated by structural resonance caused by flow fluctuations from the SSME low pressure fuel turbopump interacting with the flowliner. The pump induced backward traveling wakes that excited the liner and duct acoustics which also caused the liner to vibrate in complex mode shapes. The investigation involved an extensive effort by a team of engineers from the NASA civil servant and contractor workforce with the goal to characterize the root cause of the cracking behavior of the fuel side gimbal joint flowliners. In addition to working to identify the root cause, a parallel path was taken to characterize the material properties and fatigue capabilities of the liner material such that the life of the liners could be ascertained. As the characterization of the material and the most probable cause matured, the combination of the two with pump speed restrictions provided a means to return the Shuttle to flight in a safe manner. This paper traces the flowliner investigation results with respect to the structural dynamics analysis, component level testing and hot-fire flow testing on a static testbed. The paper will address the unique aspects of a very complex problem involving backflow from a high performance pump that has never been characterized nor understood to such detail. In addition, the paper will briefly address the flow phenomena that excited the liners, the unique structural dynamic modal characteristics and the variability of SSME operation which has ultimately ensured the safe and reliable operation of the shuttle main engines for each flight.
Sticking Up for Oedipus: Fodor on Intentional Generalizations and Broad Content

: In The Elm and the Expert, Jerry Fodor tries to reconcile three philosophical positions he is presently committed to: a computational theory of mind, intentional realism and a denotational theory of meaning. One problem he faces is this: a denotational semantics, according to which the meaning of a singular term like a name is exhausted by its referent, seems to rule out there being true intentional generalizations, or generalizations which advert to the contents of a subject's mental states. That there are such true generalizations is a major element in Fodor's intentional realism. Accordingly, Fodor is forced to find a way of dissolving this apparent incompatibility. This paper looks at his attempts to do so and concludes that they fail.
Transient Fluorescence Spectroscopy Applied to Lifetime Studies of DPA-Tb as Related to Bacterial Spores

The fluorescence lifetimes of the individual emission lines of the DPA-Tb complex have been measured in different solvents using a new technique, Transient Fluorescence Spectroscopy (TFS).
Mechanics of nanoscale surface deformation in polypropylene-clay nanocomposite

Abstract The study described here is in sequel to our studies on the mechanics of microscale deformation in thermoplastic materials where a perspective of deformation processes occurring over different strain–strain rate regimes was obtained. The specific aim here is to enhance our fundamental understanding from microscale to nanoscale deformation in polymeric material systems containing dispersion of nanoparticles, considering the growing use of polymeric materials as functional materials. A Berkovich nanoindenter was used to induce surface damage using a load of 0.5–1 mN and scratch velocity of 1 μm/s. The secondary objective is to investigate the commonality in surface deformation behavior between nano- and microscale deformation to reinforce the underlying fundamental principles governing surface deformation. Combining electron microscopy with nanoscale surface deformation experiments enabled us to extend the understanding of microscale deformation to nanoscale deformation. In the intercalated polypropylene-nanoclay system, the susceptibility to surface deformation was significantly reduced because of the shift of von Mises stress from the surface to the sub-surface region, with consequent reduction in the maximum tensile stress induced by the nanoindenter. This conclusion was consistent with electron microscopy observations and theoretical analysis.
Benign and malignant cartilage tumors of the hand.

Primary bone tumors occur in the upper extremity but are unusual in the hand and wrist. In the Mayo Clinic series, only 174 of 2334 (7%) primary benign bone tumors and 29 of 5641 (0.5%) primary malignant bone tumors involved the hand and wrist [1]. Of these bone lesions 137 of the 174 benign lesions and 12 of the 29 malignant lesions were of cartilage origin. Most cartilage lesions of the hand and wrist thus are benign but malignancy does occur. Appropriate evaluation of these lesions is critical for accurate diagnosis and successful treatment.
SU‐GG‐T‐426: Evaluation of the Interfraction Dose Variation of MammoSite HDR Brachytherapy Using the Concept of Biological Effective Dose

Purpose: To evaluate the interfraction dose variations due to changes of balloon shape and location in MammoSite HDR brachytherapy using the concept of biological effective dose (BED). Method and Materials: A method was developed to account for non‐uniform dose distribution in the BED calculation. A prescription dose of 34 Gy was delivered twice daily in 10 fractions to 19 patients. The BED value was computed by two different Method: one using the same dose distribution of fraction 1 over fraction 2–10 (constant case) and one using the actual delivered dose distribution for each fraction 1–10 (interfraction variation case — Fx case). The α/β values were adopted from literature and ranged from 2 to 11 based on specific clinical endpoints: acute effects (erythema, desquamation), late effects (fibrosis, telangiectasia) and tumor control. The α value of 0.3 Gy−1 and Tpot value of 13 days were used for cell proliferation.Results: The average difference in BED values between the constant and Fx cases was less than 0.1 Gy over the range of α/β ratios. The maximum difference was larger for late effects (fibrosis, telangiectasia) than acute effects (erythema, desquamation): −3.3 Gy and −2 Gy versus −1.5 Gy and −1.4 Gy corresponding to α/β ratio of 2 and 4 versus 8 and 11, respectively. The negative value means the BED value of Fx case is smaller than that of constant case. By disregarding high inhomogeneity in HDR brachytherapy, the simple calculation assuming uniform dose distribution tends to overestimate BED for fibrosis while underestimating BED for erythema and desquamation. Conclusion: The BED calculation accounting for non‐uniform dose distribution is more clinically relevant compared to the BED calculation which assumes uniform dose distribution across the target volume. Because the mean interfraction variation in dose was within 0.1 Gy across the target volume, the biological effect was clinically insignificant.
Index of refraction, polarizability, and equation of state of solid molecular hydrogen

The index of refraction and the equation of state (EOS) of hydrogen have been measured to high pressures, leading to a determination of the pressure dependence of the polarizability to greater than 1 mbar. A simple method for measuring the index allows for straightforward extension of both the index and EOS measurements to the highest pressures achievable in a diamond-anvil cell. {copyright} {ital 1998} {ital The American Physical Society}
Examining the contribution of social network support to the recovery process among clubhouse members

A structured interview was used to gather information pertaining to social network support and the recovery process among individuals participating in psychosocial clubhouses. Using a cross-sectional, longitudinal design, a sample of clubhouse members participated in an initial interview (n = 221). A follow-up interview with 80% of the participants was conducted approximately 14 months later. A social process model predicting recovery revealed that social network support as well as reciprocity with network members significantly contributes to understanding the recovery process over time. The study attempts to contribute to an earlier investigation of social network support and recovery from mental illness (Corrigan & Phelan, 2004).
Dynamic energy budget approach to modeling mechanisms of CdSe quantum dot toxicity

A mechanistic model of bacterial growth based on dynamic energy budget (DEB) theory is utilized to investigate mechanisms of toxicity of CdSe quantum dots (QDs). The model of QD toxicity is developed by extending a previously published DEB model of cadmium ion toxicity to include a separate model of QD toxic action. The extension allows for testing whether toxicity from QD exposure can be explained fully by dissolved cadmium exposure only, or if the separate effects of QDs need to be taken into account as well. Two major classes of QD toxicity mechanisms are considered: acclimation expressed through initial retardation of growth, and three separate metabolic effects that can be a result of QDs either reversibly or irreversibly associating with the cell. The model is consistent with the data, and is able to distinguish toxic effects due to QD nano-particles from the effects due to cadmium ions. Results suggest that, in contrast to ionic exposure where required acclimation remains constant as exposure increases, increase of the energy required for acclimation with exposure is the primary toxic effect of QDs. Reactive oxygen species measurements help conclude that increase in energetic cost of maintenance processes such as cellular repair and maintenance of cross-membrane gradients is the most important of the three metabolic effects of QD toxicity.
Continuous-flow apparatus for use in petroleum bioassay.

A system was designed for long-term bioassay of dispersed petroleum derivative, with samll amounts of insoluble material, in stable seawater concentration. The system permits simultaneous development of long-term biological indicators of oil contamination and a standardized, sensitive set of analytical methods. A description is given of the device which continuously extracts dispersed No. 2 fuel oil derivative in seawater. Illustrations are shown of the fuel oil dispersion and bioassay apparatus, the mariotte bottle used for metering fuel oil, the separation devices, and the dispersion metering tank. Distinguishable concentrations were obtained and maintained over the 96-h test periods for the various dispersed oil dilutions, thus demonstrating the feasibility of the system.
Competition and coexistence with multiple life-history stages.

Abstract: Do complex life histories affect the conditions under which competitors can coexist? We investigated this using a two‐species, two‐stage Ricker model. With complex life cycles, the competition coefficients associated with each life‐history stage suggest one of three competitive outcomes—coexistence, alternate stable states, or competitive exclusion—that depend on the relative magnitudes of intraspecific and interspecific competition. When the two stages suggest the same outcome, only that outcome can occur. When the stages suggest different outcomes, either one may prevail. It is also possible to have emergent outcomes, in which the outcome is not suggested by either stage. This can occur when the two stages suggest competitive exclusion by opposite species or when one stage suggests alternate stable states and the other suggests coexistence. Therefore, determining the mechanisms of coexistence in species with complex life histories may require consideration of competitive interactions within al...
The relative contributions of the testing cylinder and the heated plate in the hot plate procedure to the development of tolerance to morphine in rats.

Abstract Tolerance to the analgesic effect of morphine was studied using a 3 ft square hot plate to measure effect. Rats received saline, 2 ml/kg, s.c., or 5 or 10 mg/kg morphine, s.c., once weekly or once daily, respectively. They were randomly divided into major groups: tested with cylinder, tested without cylinder, ambient temperature tested with cylinder, ambient temperature tested without cylinder, and non-tested. On the final day of the experiments, all rats received morphine and were tested on the heated plate within the testing cylinder. The results clearly demonstrated that both the testing cylinder and heat are important factors in determining the results obtained in the hot plate method. Tolerance developed in all cases where the testing cylinder was employed; significantly, this occurred even in those cases where heat was not a factor and the animals acquired experience in the testing cylinder on the plate at ambient temperature. In addition, tolerance developed in all chronic morphine-treated animals tested on the heated plate, even in those cases where only heat was a factor and the testing cylinder was not employed. Most striking was the combined effect of the testing cylinder and heat. In both the daily and weekly experiments, the mean increases in reaction time of the chronic morphine-treated animals were significantly the lowest in those tested in the cylinder on the heated plate. Thus, as well as heat being an important factor, the testing cylinder is demonstrated also to significantly contribute to the degree of tolerance developed with the combination of heat and cylinder being pretotent.
428 RECTAL IMMUNOGLOBULIN PATTERNS IN HIRSCHSPRUNG'S DISEASE (HD) AND OTHER NEONATAL INTESTINAL OBSTRUCTION SYNDROMES (NIOS)

The etiology of HD remains unknown and can be confused with other NIOS. Rectal biopsy has traditionally established the diagnosis of HD. In the present investigation, rectal tissue was obtained with multipurpose suction tube at 1-2 cm above the mucocutaneous junction. Proctosigmoidoscopy was normal in all cases. In addition, rectal tissue was placed into organ culture for 24 hr. A single phase antibody radioimmunoassay was used to determine IgG, IgM & IgA levels in homogenized cultured rectal tissue (H) and its secretions (S). Results are expressed as μg of immunoglobulin/mg tissue protein. HD & NIOS have been compared to an older control group of children with Functional Abdominal Pain. For HD, an increase of IgG in both homogenate and secretions was noted compared to controls (p<0.005) and NIOS (p<0.005). Results suggest there is either increased tissue synthesis of IgG or transfer of serum maternal IgG. The explanation of the observed increased IgG in rectal tissue of children with HD is unknown
An automated CT based lung nodule detection scheme using geometric analysis of signed distance field.

The authors present a new computerized scheme to automatically detect lung nodules depicted on computed tomography (CT) images. The procedure is performed in the signed distance field of the CT images. To obtain an accurate signed distance field, CT images are first interpolated linearly along the axial direction to form an isotropic data set. Then a lung segmentation strategy is applied to smooth the lung border aiming to include as many juxtapleural nodules as possible while minimizing over segmentations of the lung regions. Potential nodule regions are then detected by locating local maximas of signed distances in each subvolume with values and the sizes larger than the smallest nodule of interest in the three-dimensional space. Finally, all detected candidates are scored by computing the similarity distance of their medial axis-like shapes obtained through a progressive clustering strategy combined with a marching cube algorithm from a sphere based shape. A free-response receiver operating characteristics curve is computed to assess the scheme performance. A performance test on 52 low-dose CT screening examinations that depict 184 verified lung nodules showed that during the initial stage the scheme achieved an asymptotic maximum sensitivity of 95.1% (175∕184) with an average of 1200 suspicious voxels per CT examination. The nine missed nodules included two small solid nodules (with a diameter ≤3.1 mm) and seven nonsolid nodules. The final performance level after the similarity scoring stage was an absolute sensitivity level, namely, including the nine missed during the initial stage, of 81.5% (150∕184) with 6.5 false-positive identifications per CT examination. This preliminary study demonstrates the feasibility of applying a simple and robust geometric model using the signed distance field to identify suspicious lung nodules. In the authors’ data set the sensitivity of this scheme is not affected by nodule size. In addition to potentially being a stand alone approach, the signed distance field based method can be easily implemented as an initial filtering step in other computer-aided detection schemes.
Trypsin induces Ca2+-activated Cl- currents in X. laevis oocytes

Abstract The protease trypsin induces Ca2+-activated Cl− currents when applied in concentrations as low as 0.1 mg ml to defolliculated, voltage clamped X. laevis oocytes. The response is dose-dependent and specific, as other proteases (chymotrypsin, Lys-C and Arg-C), or trypsin pretreated with soybean trypsin inhibitor, did not induce currents. Intracellular trypsin injection did not induce responses. The current does not appear to result from proteolytic activation of the endogenous receptor for lysophosphatidic acid, the only known Ca2+-mobilizing receptor consistently present in oocytes. These results suggest the presence on the oocyte membrane of a specific receptor for trypsin.
The effect of alloying on Tc in superconducting YNi2−xMxB2C (M = Co, Cu)

Abstract In order to probe the influence of the density of states (DOS) at the Fermi level N ( E F ) on the superconducting transition temperature T c , we investigated the effect of alloying on T c in YNi 2− x M x B 2 C (M = Co, Cu). The lattice contracts (expands) as a result of substitution of Ni with Co (Cu). From the observed drop in T c for both substitutions, we infer that N ( E F ) may lie very close to a maximum in the DOS in the parent compound YNi 2 B 2 C, in agreement with published band-structure calculations. However, the much steeper drop in T c for Co substitution (d T c /d x = −45 K compared to −19 K for Cu) indicates that either the peak in the DOS is asymmetric in energy, or alloying affects both N ( E F ) and the electron-phonon coupling strength.
Stability of the Martian Atmosphere

A detailed chemical dynamic model is presented for a moist martian atmosphere. Recombination of carbon dioxide is catalyzed by trace amounts of water. The abundances of carbon monoxide and molecular oxygen should vary in response to changes in atmospheric water and atmospheric mixing.
Poly(ethylene oxide) electrolytes containing mixed salts

An unusual conductivity enhancement occurs in PEO-based ZnBr2/LiBr electrolytes of composition, [xZnBr2 + (1 − x)LiBr](PEO)16 with x = 0.00, 0.05, 0.50, 0.75, 1.00. The conductivity of the mixed-salt electrolytes is higher than that of either pure salt electrolyte. The highest conductivity, observed for x = 0.5, is two orders of magnitude higher than that of pure LiBr(PEO)16 and one order higher than ZnBr2(PEO)16. In contrast, the conductivity of mixed Mg (CIO4)2/LiCIO4 electrolytes, [xMg(CIO4)2 + (1 − x) LiCIO4](PEO)16 where x = 0.00, 0.20, 0.50, 0.80, 1.00, increases monotonically with the mole fraction of the higher conductivity component, LiCIO4(PEO)16. The conductivity and differential scanning calorimetry (DSC) results suggest that the conductivity enhancement in the ZnBr2/LiBr electrolytes results from a change in charge carrier type and concentration, whereas the conductivity change in the Mg(CIO4)2/LiCIO4 electrolytes arises from a change in the microscopic viscosity of the electrolytes. © 1993 John Wiley & Sons, Inc.
Yeast Cystathionine β-Synthase Is a Pyridoxal Phosphate Enzyme but, Unlike the Human Enzyme, Is Not a Heme Protein

Abstract Our studies of cystathionine β-synthase fromSaccharomyces cerevisiae (yeast) are aimed at (1) clarifying the cofactor dependence and catalytic mechanism and (2) obtaining a system for future investigations of the effects of mutations that cause human disease (homocystinuria or coronary heart disease). We report methods that yielded high expression of the yeast gene in Escherichia coli and of purified yeast cystathionine β-synthase. The absorption and circular dichroism spectra of the homogeneous enzyme were characteristic of a pyridoxal phosphate enzyme and showed the absence of heme, which is found in human and rat cystathionine β-synthase. The absence of heme in the yeast enzyme facilitates spectroscopic studies to probe the catalytic mechanism. The reaction of the enzyme with l-serine in the absence of l-homocysteine produced the aldimine of aminoacrylate, which absorbed at 460 nm and had a strong negative circular dichroism band at 460 nm. The formation of this intermediate from the product, l-cystathionine, demonstrates the partial reversibility of the reaction. Our results establish the overall catalytic mechanism of yeast cystathionine β-synthase and provide a useful system for future studies of structure and function. The absence of heme in the functional yeast enzyme suggests that heme does not play an essential catalytic role in the rat and human enzymes. The results are consistent with the absence of heme in the closely related enzymesO-acetylserine sulfhydrylase, threonine deaminase, and tryptophan synthase.
Long-lived charged multiple-exciton complexes in strong magnetic fields.

We consider the charged exciton complexes of an ideal two-dimensional electron-hole system in the limit of strong magnetic fields. A series of charged multiple-exciton states is identified and variational and finite-size exact-diagonalization calculations are used to estimate their binding energies. We find that, because of a hidden symmetry, bound states of excitons and an additional electron cannot be created by direct optical absorption and, once created, have an infinite optical recombination lifetime. We also estimate the optical recombination rates when electron and hole layers are displaced and the hidden symmetry is violated. {copyright} {ital 1996 The American Physical Society.}
The relationship between interferon-γ and keratinocyte alloantigen expression after burn injury

Background Cultured keratinocyte (CK) and cadaveric skin allografts have prolonged survival in patients with massive thermal injury. It is unclear if this delayed rejection is due to impaired host responsiveness or decreased graft immunogenicity. Although burn injury has been shown to decrease parameters of allograft response, no studies have examined the effect of burn injury on alloantigen expression. This study investigated the effect of burn size on class II antigen expression in CK allografts as well as on tissue levels of interferon-γ (IFN-γ), the principle regulator of alloantigen expression. Methods Anesthetized CBA mice (n = 64) received a 0%, 20% partial-thickness (PT), 20% full-thickness (FT), or 40% FT contact burn. Forty-eight hours later, wounds were partially excised and covered with CK allografts from C57BL/6 donors. Five days after burn injury, grafts were analyzed for donor-specific class II antigen. Protein expression was determined by Western immunoblotting and quantified with video densitometry. Wound, serum, and unburned skin levels of IFN-γ were determined by enzyme-linked immunosorbent assay. Groups were compared by Fisher's analysis of variance. Results As burn size increased, class II antigen expression decreased (p < 0.001). This corresponded with decreased wound and skin levels of IFN-γ after 40% burn (p < 0.05) ; however, wound IFN-γ was significantly elevated after 20% PT and FT burns (p < 0.01). Serum IFN-γ increased as burn size increased (p < 0.01). Conclusions Burn injury decreases the antigenicity of CK allografts, which partly explains delayed allograft rejection after burn injury. Although wound IFN-γ increases after minor thermal injury, the profound decrease in wound and skin IFN-γ after a major burn corresponds with diminished class II antigen expression. The decreased availability of IFN-γ after major thermal injury provides a mechanism for limited allograft tolerance.
A Life-Span View of Social Cognition.

Using an organismic framework for understanding development, it is argued that cognition must be understood in the context of real‐life adaptation, and as such social cognition is an important area of investigation. This paper argues for a unified theoretical approach to encompass both child and adult social‐cognitive development, and a life‐span model is presented which synthesizes work from the child and adult social‐cognitive literatures. Using Werner's orthogenetic principle of development, a sequence of seven levels is presented, culminating in mature relativistic and dialectical reasoning. Implications for education are discussed.
Discovery of co2 ice and leading–trailing spectral asymmetry on the uranian satellite ariel

Abstract New 0.8- to 2.4-μm spectral observations of the leading and trailing hemispheres of the uranian satellite Ariel were obtained at IRTF/SpeX during 2002 July 16 and 17 UT. The new spectra reveal contrasts between Ariel’s leading and trailing hemispheres, with the leading hemisphere presenting deeper H2O ice absorption bands. The observed dichotomy is comparable to leading–trailing spectral asymmetries observed among jovian and saturnian icy satellites. More remarkably, the trailing hemisphere spectrum exhibits three narrow CO2 ice absorption bands near 2 μm. This discovery of CO2 ice on one hemisphere of Ariel is its first reported detection in the uranian system.
Migration tendency in juvenile steelhead trout, Salmo gairdneri Richardson, injected with thyroxine and thiourea

Juvenile steelhead trout, Salmo gairdneri injected with thyroxine (T4) near the time of seaward migration exhibited a significantly lower migration tendency than untreated controls of fish injected with saline, thiourea, or a combination of T4 and thiourea. Fish injected with thiourea alone or in combination with T4 prior to the time of maximum migration tendency showed enhanced migration over untreated and saline injected controls and those injected with T4 alone. Injections of T4 or a combination of T4 and thiourea elevated plasma T4 and tri-iodothyronine (T3) concentrations, while injection of thiourea alone depressed thyroid hormone levels relative to saline-injected controls. Plasma concentrations of T3 and T4 returned to control levels within 10 days in all groups. We suggest that thyroid hormones are antagonistic to mechanisms underlying seaward migration of steelhead trout and that these antagonistic effects must be overcome before migration tendency is expressed.
Increasing Eligibility for Nipple-Sparing Mastectomy

Background Eligibility for nipple-sparing mastectomy (NSM) varies widely on the basis of patient and tumor factors.
Computational study of methane functionalization by a multiply bonded, Ni-bis(phosphine) complex

Abstract A computational chemistry study of nickel-catalyzed group transfer to methane is presented. Two mechanisms were evaluated: a one-step mechanism involving [1+2] insertion of E into the C–H bond of methane, and a two-step [2 π + 2 σ ] mechanism involving addition of the C–H bond of methane across the Ni E bond to a square planar Ni II intermediate, followed by C–E reductive elimination. Analysis of the energetics for the different mechanistic steps implies a possible competition between the two mechanisms for carbene transfer. For nitrene transfer, the [1+2] pathway is predicted to be the preferred route. Finally, for phosphinidene transfer, the [2 π + 2 σ ] mechanism is calculated to be the preferred mechanism. The two mechanisms studied – [1+2] and [2 π + 2 σ ] – entail exothermic individual reactions, coupled with reasonable enthalpic barriers. Furthermore, regeneration of the catalyst active species by reaction with a group transfer reagent XE is highly exothermic. The calculations thus indicate that (P ∼ P)Ni E (P ∼ P denotes a chelating bis-phosphine ligand) deserve consideration as plausible starting points in the search for improved hydrocarbon functionalization catalysts.