cssi/SciSciGPT-SciSciNet huggingface dataset:
N-methyl-D-aspartic acid receptor messenger ribonucleic acid levels and luteinizing hormone release in immature female rats: effects of stage of pubertal development and exposure to ethanol

This research was designed to determine 1) whether changes occur in the levels of N-methyl-D-aspartic acid (NMDA) receptor (NMDA-R) messenger RNA (mRNA) in the reproductive hypothalamus of female rats as they approach puberty, 2) whether NMDA-R stimulation would promote differential LH responses during the specific stages of peripubertal development, and 3) whether ethanol (ETOH), which is known to affect the NMDA-R in other brain systems, can alter NMDA-R-activated LH secretion at puberty. In the first experiment, female rats were killed at 15, 20, 25, and 34-36 days of age to determine the levels of mRNA that code for the NMDA-R, specifically NMDA-R1, in the arcuate nucleus-median eminence (AN-ME) and preoptic area (POA) during pre- and peripubertal development by a ribonuclease protection assay. Results indicate that in juvenile animals, NMDA-R mRNA levels in the AN-ME increased at 25 days (P < 0.01). In the POA, the levels increased at 20 days (P < 0.05), but were unchanged at 25 days. During the peripubertal period, NMDA-R gene expression in the AN-ME did not change; however, gene expression in the POA increased (P < 0.05) during first proestrus, then declined during first estrus. In the second experiment, NMDA-R stimulation with N-methyl-D,L-aspartic acid (NMA; 2.5 mg/kg) produced differential stimulatory effects on LH release depending upon the stage of pubertal development. In this regard, significant post-NMA percent increases in LH released over pre-NMA (basal) levels occurred during anestrus (46%; P < 0.01) and first proestrus (95%; P < 0.01), with nonsignificant increases of 18% and 28% during first estrus and diestrus, respectively. Finally, a 3 g/kg dose of ETOH given intragastrically 90 min before the NMA challenge blocked (P < 0.05) NMA-induced LH release during first proestrus. In conclusion, these findings demonstrate regional differences in the timing of NMDA-R gene expression in the reproductive hypothalamus during pubertal development, show differential responses of LH to NMDA-R activation during the peripubertal period, and continue to demonstrate the vulnerability of the hypothalamic-pituitary axis to the detrimental effects of ETOH at this critical time of development.
Heats of formation of HNO and some related species

Abstract A critical review of the heat of formation of HNO is presented. This molecule and its thermodynamics parameters play crucial roles in the chemical mechanisms of propellant combustion and NOx pollutant chemistry. It was found that predissociation experiments, which have gone largely unnoticed for about 15 years, lead to a significant revision in the recommended value. The new value, 25.6−0.1+0.6 kcal/mol (298 K; 26.3 kcal/mol at 0 K), is 1 to 2 kcal/mol higher than previous recommendations and has much narrower error limits. Heats of formation of NO, NH2OH, HNO+, and HNO− are also briefly examined, and recommendations are made.
By what measure? Family time devoted to children in the United States.

We argue that previous research on time devoted to child care has paid insufficient attention to the conceptualization of care time. Three separate problems are evident. First, the conventional focus on explicit activities with children distracts attention from the larger responsibilities of “passive” care, which ranges from time when children are sleeping to time when they are in the same general area but are not engaged in an activity with parents. Second, the empirical analysis of activity time focuses almost exclusively on parents, overlooking the role of relatives such as grandmothers and siblings. Third, the measurement of active care time often ignores the impact of overlaps among both care providers and recipients. Our analysis of the Child Development Supplement of the Panel Study of Income Dynamics sheds light on these three problems and presents new measures of passive and active care time.
Tuning Mechanical Properties of Chondroitin Sulfate-Based Hydrogels Using the Double-Network Strategy

The double-network (DN) hydrogel concept developed by J.P. Gong and Y. Osada builds upon interpenetrating networks by combining brittle and ductile components to have significantly enhanced fracture properties. The generality of the DN effect was tested by creating biopolymer-based hydrogels of methacrylated chondroitin sulfate (MCS) and polyacrylamide (PAAm) and extended upon creating DNs of MCS and poly(N,N dimethyl acrylamide) (PDMAAm), verifying that DNs were not limited to the original combination of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS)/polyacrylamide (PAAm). Further, the mechanical properties were varied by changing the monomer concentrations, cross-linker concentrations and the addition of cross-linking groups through copolymerizations of MCS and poly(ethylene glycol) diacrylate (PEGDA). Overall, this work demonstrates that a broad range of mechanical properties achievable through DN effect under tension and compression, generally independent of the swelling degree, which is fundamentally different behavior than possible with single networks.
CDC2 ACTIVATION IN FISSION YEAST DEPENDS ON MCS6 AND CSK1, TWO PARTIALLY REDUNDANT CDK-ACTIVATING KINASES (CAKS)

Abstract Cyclin-dependent kinases (Cdks) are fully active only when phosphorylated by a Cdk-activating kinase (CAK) [1]. Metazoan CAK is itself a Cdk, Cdk7, whereas the CAK of Saccharomyces cerevisiae is a distinct enzyme unrelated to Cdks [1]. The Mcs6–Mcs2 complex of Schizosaccharomyces pombe is a putative CAK related to the metazoan enzyme [2,3]. Although the loss of Mcs6 is lethal, it results in a phenotype that is inconsistent with a failure to activate Cdc2, the major Cdk in S. pombe [3]. We therefore tested the ability of Csk1, a putative regulator of Mcs6 [4], to activate Cdk–cyclin complexes in vitro . Csk1 activated both the monomeric and the Mcs2-bound forms of Mcs6. Surprisingly, Csk1 also activated Cdc2 in complexes with either Cdc13 or Cig2 cyclins. When a double mutant carrying a csk1 deletion and a temperature-sensitive mcs6 allele was incubated at the restrictive temperature, Cdc2 was not activated and the cells underwent a cell division arrest prior to mitosis. Cdc2–cyclin complexes isolated from the arrested cells could be activated in vitro by recombinant CAK, whereas complexes from wild-type cells or either of the single mutants were refractory to activation. Thus, fission yeast contains two partially redundant CAKs: the Mcs6–Mcs2 complex and Csk1. Inactivation of both CAKs is necessary and sufficient to prevent Cdc2 activation and cause a cell-cycle arrest. Mcs6, which is essential, may therefore have required functions other than Cdk activation.
Diurnal patterns of ammonia release in marine and terrestrial isopods

Abstract 1. 1. An inverse exponential relationship between the rate of ammonia excretion and dry body weight has been established in a selected isopod, Cirolana harfordi. 2. 2. Similar diurnal patterns of rate of ammonia release have been demonstrated in eight species of isopods including members of the Oniscoidaea, Valvifera and Flabellifera. 3. 3. C. harfordi exposed to either normal light/dark photoperiodism, continuous light or continuous dark retain a characteristic pattern of ammonia release. 4. 4. Porcellio scaber and Idotea resecatawere found to release ammonia during the afternoon in discrete events, with comparable rates of release. No correlation was found between fecal production and ammonia release.
A “Big Data” View of the Tumor “Immunome”

Tumors are complex masses containing not just neoplastic cells but also stromal cells, neovasculature, and a gamut of immune cells. In this issue, Bindea et al. (2013) identify a surprising new "immune landscape" associated with prolonged disease-free survival.
Behavioral effects of fetal neural transplants: Relevance to Huntington's disease

Animal models of Huntington's disease (HD) and other neurological disorders have proven useful for examining the anatomical, neurochemical, and behavioral alterations in these diseases. Investigators have taken advantage of new excitotoxic models that appear to successfully simulate the neurobiological and behavioral characteristics of HD with remarkable homology. Selective excitotoxic compounds allow for a more precise and controlled lesion with which to examine the relationship between striatal damage and behavioral abnormalities. In addition, these models provide new approaches for developing and testing various treatments for HD. Fetal neural tissue transplanted into the excitotoxin-lesioned animal can integrate with the host brain and promote neurochemical and functional recovery. Neural grafting paradigms may be viewed as potential therapies for treating neurodegenerative diseases and as aids in deciphering the regenerative mechanisms of the central nervous system. Further research is necessary, however, to determine the negative and positive effects of neural transplantation. In addition, existing behavioral models need to be refined to allow for better evaluation of the subtle topographic changes in behavior resulting from fetal tissue transplantation.
Retrieval processes in transactive memory systems

Two experiments examined retrieval processes in transactive memory systems (D. M. Wegner, 1987). In Experiment 1, intimate couples who worked face to face performed better on a knowledge-pooling task than strangers who worked face to face and better than intimate couples who worked via a computer conferencing system. Additional analyses indicated that intimate couples when interacting face to face were better able to determine which partner was correct on questions that only 1 member knew the answer to prior to discussion. In Experiment 2, intimate couples scored significantly better on the knowledge task when they had access to either nonverbal or paralinguistic communication cues than when they had access to neither. Taken together, the results indicate that both nonverbal and paralinguistic communication play an important role in the retrieval of knowledge in transactive memory systems.
Mechanisms contributing to the neutralization of HIV-1

Abstract The phenomenon of virus neutralization is a function of three variables: the antibody (Ab), the virus and the target cell. Variation in any one of these parameters may drastically affect the results of assays for neutralization. In focusing on the virus as a variable in assays for the neutralization of HIV-1, it has been shown that the range of sensitivity of primary HIV-1 isolates is quite large. This may be due to the structure and biology of the virus particle, its density of envelope proteins, its ability to retain or shed these proteins, and its phenotype, determining the type of cells it will infect. The Ab used for neutralization also contributes to the efficiency of neutralization. Thus, the ‘match’ between the specificity of the Ab and the structure and availability of the epitope on the virus will affect the interaction and contribute to the resultant reduction in virus infectivity. Similarly, the strength of interaction between the virus and the neutralizing Ab, dependent on the affinity of the Ab for the virus epitope, will also be a determining factor. However, other factors contribute to the neutralization sensitivity of primary isolates of HIV-1. One factor that has been almost completely overlooked in the recent literature is the role that the target cell plays in revealing reduced virus infectivity. The facility and mechanism through which different cell types bind a virion and are infected by it will contribute profoundly to the efficiency with which Ab-mediated neutralization can be detected. These factors are discussed below with particular reference to interpreting (and re-interpreting) the current literature on HIV-1 neutralization.
The role of discourse structure in understanding anaphora

Abstract Any two utterances in a discourse may be closely related, as in question-answer pairs, or more loosely related, as in various declarative sequences, or they may be virtually independent, as when one is an interruption or digression. This paper reports four experiments on how such differences in utterance relations influence resolving an anaphor. Subjects in the experiments were faster to understand verb phrase ellipsis when the utterance containing the antecedent was in some way picked out as likely to be related to material later on. This finding suggests that readers may selectively keep information available if it is likely to be needed for interpreting subsequent input (including anaphors).
Robotics enabled in-home environment screening for fall risks

Fall risks present in living environment are the leading cause of mortality in older adults. Falling on the floor may cause great harm to older people living alone, which in many cases goes unnoticed for several days until the symptoms become severe. Limited number of trained professionals to assess a house for fall risks and higher costs make the prevention of fall risks inaccessible to many necessitous patients. Removing these potential risk factors can provide older adults a safer living condition for their daily activities. This paper presents the design of a robot control system for in-home environment screening. This system is designed to be capable of supporting both manual and autonomous fall-risk assessment. The developed system allows a teleoperator to assess a house remotely along with capabilities to measure distance between 2 objects, assessing lighting conditions, and interacting with the patient using telepresence.
Cisplatin as a radiation sensitizer in the treatment of advanced head and neck cancers. Results of a phase II study.

Background. Surgery and radiotherapy mainstays in the management of advanced head and neck cancer, although historically, only 20–30% of patients survive. Therefore, in an attempt to improve locoregional control and survival, a multimodal protocol using cisplatin as a radiosensitizer was implemented. Methods. Between 1984 and 1990,68 patients with advanced head and neck cancer (Stages III and IV) were treated with a regimen consisting of an induction phase of 4500 cGy and two cycles of cisplatin followed by an eradicative phase of either radical surgery (Group A, 27 patients) or radical radiotherapy (Group B, 41 patients). The maintenance phase chemotherapy consisted of adjuvant 5-fluorouracil (5-FU) and cisplatin after completion of locoregional treatment. Of the 68 patients, 19 had Stage III disease, and 49 had Stage IV; 21 had no regional lymph node metastases (No), and 47 had regional lymph node metastases (N+). Results. The induction phase yielded a 26% (18 patients) complete response (CR) rate and a 57% (39 patients) partial response (PR) rate (response > 50%), yielding an overall response rate of 83%. Eleven patients (16%) had stable disease (ST) (i. e., < 50% response). The 2-year survival rates by initial treatment response for patients who had a CR, a PR, and stable disease were 53%, 56%, and 36%, respectively; for Groups A and B, 63% and 45%, respectively; for Stages III and IV, 68% and 43%, respectively; and for NO and N+, 69% and 43%, respectively. In Group A, 14 of 27 patients (52%) had no viable tumor in the surgical specimen (i. e. had pathologic complete tumor clearance [CTC]); this subgroup had a 5-year survival rate of 58%. Ten patients (37%) who had gross total resection of tumor with negative margins but had tumor present in the specimen had a 5-year survival of 22%. In Group B, the 5-year survival rate was 43% for 27 patients who achieved CR after completion of radical radiotherapy (total tumor dose, 6480–7020 cGy). The 5-year survival rate of the 14 patients who had a PR and stable disease after radical radiotherapy and 3 patients whose resection was incomplete was 0%. The overall 2- and 5-year survival rates for all patients were 53% and 32%, respectively. Of 21 patients in whom treatment failed, most (90%) had a locoregional recurrence: 13 local recurrences (62%), 5 regional (24%), and 1 locoregional (5%). Two patients (10%) experienced failure at distant sites (the lung). Major treatment-related morbidity developed in two patients. Conclusions. Although induction chemotherapy-radiotherapy produces a high clinical response rate, this does not translate into improved survival compared with historical controls. A subgroup that showed complete tumor clearance (CTC or pathologic complete response) at surgery had an apparent improved survival and merits further study. Patient selection did not appear to be a factor for the CTC group, because the majority of patients in this group had partial responses to induction therapy, nodal disease and advanced tumor stage, and tumor presence in unfavorable sites.
Modelling of dispersion and dead space in an air chamber

A combined model consisting of an active region and a stagnant region is used in representing the air flow characteristics in a continuous flow system. The active region is represented by the one dimensional axial dispersion model while the stagnant region is considered to be a dead volume having no fluid interchange with the active region. The mathematical model is fitted to experimental data obtained by subjecting the system to tracer step inputs. In the process of model fitting a dimensionless parameter of Pe. (Peclet number of the active region) is estimated. The effects of the internal geometry and structure of the flow system on the flow patterns are analyzed and substantiated by experimental data. Two possible mechanisms explaining the formation of stagnant regions have been proposed — that of reduced length, and that of reduced cross-section. For the present investigation, the reduced length mechanism is found to explain the experimental data better. On utilise un modele combine, forme d'une region active et d'une region stagnante, pour representer les caracteristiques de l'ecoulement de l'air dans un systeme d'ecoulement continu. Le modele de dispersion axiale a une dimension represente la region active, tandis qu'on considere la region stagnante comme un volume inerte dans lequel il ne se fait aucun echange mutuel de fluide avec la region active. On adapte le modele mathematique aux resultats experimentaux obtenus en introduisant un indicateur (ou traceur) par etapes. Dans le processus d'adaptation du modele, on evalue un parametre Pea sans dimensions (nombre de Peclet de la region active). On analyse les effets de la geometrie interne et de la structure du systeme d'ecoulement sur l'allure de l'ecoulement et les verifie experimentalement. On a propose deux mecanismes possibles pour expliquer la formation des regions stagnantes, a savoir le mecanisme de longueur reduite et celui d'une coupe tranversale; dans le cas du present travail, on trouve que le mecanisme de longueur reduite explique mieux les resultats experimentaux.
Measurement of oxidatively induced base lesions in liver from Wistar rats of different ages.

Mitochondrial and nuclear DNA were isolated from the livers of young (6 -7 month) and old (23-24 month) Wistar rats and the levels of 10 different oxidatively induced lesions were analyzed by gas chromatography/mass spectrometry. This is the first study to measure several different oxidatively induced base lesions in both mitochondrial and nuclear DNA as a function of age. No significant age effects were observed for any lesion. Furthermore, contrary to expectations, we did not observe elevated levels of oxidatively induced base lesions in mitochondrial DNA. This contrasts with 50-fold differences reported for several lesions between mitochondrial and nuclear DNA from porcine liver (Zastawny et al., Free Radic. Biol. Med.24:722-725, 1998). The fact that different lesion levels are observed even when similar techniques are employed emphasizes that the role of oxidative mitochondrial DNA damage and its repair in aging must continue to be the subject of intense investigation. Questions concerning endogenous levels of damage should be revisited as existing methods are improved and new methods become available. © 1999 Elsevier Science Inc.
Karyotyping human chromosomes by combinatorial multi-fluor FISH

We have developed epifluorescence filter sets and computer software for the detection and discrimination of 27 different DNA probes hybridized simultaneously. For karyotype analysis, a pool of human chromosome painting probes, each labelled with a different fluor combination, was hybridized to metaphase chromosomes prepared from normal cells, clinical specimens, and neoplastic cell lines. Both simple and complex chromosomal rearrangements could be detected rapidly and unequivocally; many of the more complex chromosomal abnormalities could not be delineated by conventional cytogenetic banding techniques. Our data suggest that multiplex-fluorescence in situ hybridization (M-FISH) could have wide clinical utility and complement standard cytogenetics, particularly for the characterization of complex karyotypes.
Axonal Atrophy from Permanent Peripheral Axotomy in Adult Cat

The peripheral axons of lower motor and spinal ganglion neurons were permanently transected and not allowed to regrow to target tissue in adult cats by amputation of the hind limb at the hip. The number and sizes of L-7 lower motor neurons at two levels (cell bodies of lateral group motor neurons and myelinated fibers [MFs] of ventral root) and of L-7 spinal ganglion neurons at two levels (cell bodies of L-7 spinal ganglion and MFs of dorsal root) were morphometrically evaluated in groups of cats at 3 months, 9 months, and 18 months after amputation and compared with the number and sizes of neurons in controls or with those on the opposite side. The number of neurons decreased only minimally after amputation. The diameter of neuron cell bodies was only equivocally reduced. By contrast, the median diameter and the peak diameter of both large and small MFs of dorsal and ventral nerve roots were significantly (approximately 30%) less than those of controls. This reduction in diameter of MFs is judged to be related to chronic axonal atrophy rather than to selective loss of large fibers. Permanent transection of distal axons should therefore prove to be a good model of chronic axonal atrophy.
Inhibition of cleavage of moloney murine leukemia virus gag and env coded precursor polyproteins by cerulenin

Abstract Cerulenin, an inhibitor of de novo fatty acid (and cholesterol) biosynthesis, has been shown to significantly decrease (>75%) the amount of Moloney murine leukemia virus (M-MuLV) released into the culture medium of chronically infected mouse fibroblasts (I. Katoh, Y. Yoshinaka, and R. B. Luftig, 1986, Virus Res. , in press). In order to clarify the mechanism by which this decrease in virus production occurs, we analyzed the kinetics of gag and env coded protein synthesis in M-MuLV infected, cerulenin-treated cells by immunoprecipitation with monospecific antisera to p30, p12, p10, gp70, and p15(E). We found that in pulse (15 min-2 hr)-chase (0–4 hr) experiments the cleavage of not only Pr65 gag to p30 and other gag coded proteins but Pr80 env to gp70 and Pr15(E) as well, was greatly reduced by cerulenin treatment. Further, since the total amount of label in the Pr65 gag and Pr80 env bands remained about the same or was slightly decreased in 2-hr pulsed, cerulenin-treated cells, this suggests that cerulenin decreases virus production, in part, by inhibiting the cleavage of both precursor gag and env coded polyproteins during virus assembly and budding at the cell membrane. We also observed that at longer chase periods (4 hr), the effect of cerulenin could be partially overriden in that minor amounts of cleaved gag and env coded polyproteins were produced and assembled into virion particles. However, these particles contained abnormally large amounts of the uncleaved precursor Pr65 gag , suggesting that maturation was incomplete. The above results suggest two independent, but not exclusive, possible mechanisms of cerulenin action to block M-MuLV production, viz. (i) cerulenin decreases the pool of fatty acids, thereby inhibiting fatty acid acylation of Pr65 gag , as well as Pr80 env , and thus preventing the interaction between gag (the p15 antigenic determinant on Pr65 gag ) and env [the p15(E) antigenic determinant of Pr15(E)] coded gene products at the cell membrane needed for efficient virus assembly (M. Satake and R. B. Luftig, 1983, Virology 124 , 259–273), and (ii) cerulenin inhibits one or more proteolytic enzymes responsible for the cleavage of Pr65 gag and Pr80 env .
Transport of a synaptotagmin-YFP fusion protein in sympathetic neurons during early neurite outgrowth in vitro after transfection in vivo.

Abstract Developing neurons are engaged in neurite outgrowth as well as the synthesis and transport of proteins involved in synaptic transmission. Very little is known about when transport is established in these rudimentary neurites. We used a novel technique to visualize protein transport during the early hours of neurite outgrowth in culture. Recombinant adenoviruses were used to express a synaptotagmin–YFP fusion protein in the superior cervical ganglia of neonatal rats in vivo and protein transport was examined in neuronal cultures established from the superior cervical ganglions (SCGs). We find that, as early as 4 h in culture, synaptotagmin–YFP was present in the cytoplasm, lamellipodia, filopodia and growth cones. Protein expression appeared punctate in neurites at 8 h in vitro and is consistent with a vesicular localization. These results indicate that the machinery to transport synapse-specific proteins is functional in rudimentary neurites at this time and indicates that this technique can be used to study early neuronal development.
Rationale for a randomized controlled trial comparing two prophylaxis regimens in adults with severe hemophilia A: the Hemophilia Adult Prophylaxis Trial

A major goal of comprehensive hemophilia care is to prevent occurrence of bleeds by prophylaxis or regular preventive factor, one or more times weekly. Although prophylaxis is effective in reducing bleeding and joint damage in children, whether it is necessary to continue into adulthood is not known. The purpose of this article is to describe a Phase III randomized controlled trial to evaluate prophylaxis comparing two dose regimens in adults with severe hemophilia A. I hypothesize that adults with mature cartilage and joints are less susceptible to joint bleeds and joint damage, and that once-weekly recombinant factor VIII prophylaxis, with up to two rescue doses per week, is as effective as thrice-weekly prophylaxis in reducing bleeding frequency, but less costly and more acceptable, with higher quality of life. The ultimate goal of this project is to determine whether once-weekly prophylaxis is any worse than thrice-weekly prophylaxis in reducing joint bleeding frequency, while potentially utilizing less factor, at lower cost, leading to a better quality of life. This is an innovative concept, as it challenges the current paradigm of thrice-weekly prophylaxis in adults, which is based on dosing in children. Furthermore, this trial will assess interdose thrombin generation, a novel tissue factor-based assay of hemostasis, to determine if individualized thrombin generation can predict more individualized prophylaxis dosing, which would be practice changing.
Control of gluconeogenesis in biotin-deficient rat liver.

Abstract Incorporation of gluconeogenic precursors such as l -alanine-U- 14 C, l -aspartate-U- 14 C, succinate-1,4- 14 C, NaH 14 CO 3 and glycerol-U- 14 C into blood glucose and liver glycogen was studied in control and pair-fed biotin-deficient rats. It was observed that only glycerol-U- 14 C was utilized equally efficiently by control and deficient animals for glucose synthesis. A study of the levels of gluconeogenic intermediates, as well as the levels of reduced and oxidized forms of pyridine nucleotides in livers of fasted control and deficient animals, indicated two sites of control of gluconeogenesis in biotin deficiency: at the pyruvate carboxylase step and at the glyceraldehyde-3-phosphate dehydrogenase step. Under these conditions, abnormally large amounts of lactate were excreted in the urine of biotin-deficient animals.
Three dimensional flow field due to a vortex and source line spanning an annulus

Abstract A theoretical investigation of the three dimensional potential flow field due to a vortex and source line spanning an annulus is carried out in this paper. The three dimensional effects due to finite radius hub and annulus walls are found to be appreciable, especially for a low hub/tip ratio configuration. The discrepancy between the two and three dimensional solutions are found to be large near the hub, moderate at the tip and negligibly small at the mid radius.
The Role of Antihistamines in the Treatment of Vasomotor Rhinitis

The pathogenesis of vasomotor rhinitis is not understood. It is unlikely that antihistamines, based on their H1 antagonist activity alone, would be effective in this disorder. Nonetheless, at least one double-blind, placebo-controlled multicenter trial has found that intranasal azelastine relieves symptoms of this disorder better than placebo. The mechanism responsible for its beneficial effect in nonallergic rhinitis is unclear but probably relates to "anti-inflammatory/antiallergic" activities. Such mechanisms have been demonstrated for a number of different oral antihistamines, but often the concentrations required in vitro are higher than those that are normally achieved in vivo using recommended dosing. It has been postulated that intranasal administration, which can achieve high local levels, might be a factor responsible for enhancing the "anti-inflammatory/antiallergic" properties. Interpreting this information allows one to conclude that antihistamines may be potentially effective agents in vasomotor rhinitis, and are more likely to be so when administered intranasally, despite the fact that data documenting this beneficial effect are sparse.
A cold-sensitive mutant of Salmonella typhimurium which requires tryptophan for growth at 20°

Abstract 1. 1. A cold-sensitive mutant of Salmonella typhimurium (JL65) is described which requires tryptophan for groqth at 20° but not 37°. 2. 2. The mutant accumulates indole and indoleglycerol at both 20 and 37° in minimal medium. Upon shift of a culture growing in minimal medium from 37 to 20° growth stops immediately; upon shift back to 37° growth resumes immediately. 3. 3. Assays of extracts from cells grown at 37° showed high (derepressed) levels of anthranilate synthetase and tryptophan synthetase ( l -serine hydrolase: adding indole, EC 4.2.1.20) A protein when assayed at 37 or 20°; but only low levels of tryptophan synthetase B protein were detected in assays done at 37° while no activity was detected in assays done at 20°. 4. 4. Transduction experiments show that the mutation maps in the structural gene coding for the tryptophan synthetase B protein. 5. 5. The cold-sensitivity of JL65 is caused by an alteration in the tryptophan synthetase B protein making it susceptible to reversible inactivation at 20°.
Solving Word Problems using Schemas: A Review of the Literature

Solving word problems is a difficult task for students at-risk for or with learning disabilities (LD). One instructional approach that has emerged as a valid method for helping students at-risk for or with LD to become more proficient at word-problem solving is using schemas. A schema is a framework for solving a problem. With a schema, students are taught to recognize problems as falling within word-problem types and to apply a problem solution method that matches that problem type. This review highlights two schema approaches for 2(nd)- and 3(rd)-grade students at-risk for or with LD: schema-based instruction and schema-broadening instruction. A total of 12 schema studies were reviewed and synthesized. Both types of schema approaches enhanced the word-problem skill of students at-risk for or with LD. Based on the review, suggestions are provided for incorporating word-problem instruction using schemas.
Biomedical information resources for Duke undergraduates (BME 265)

BME 265 is a credit course exploring the strategies and tools necessary to navigate the ever increasing information resources available in the fields of biomedical engineering. Each class, a combination of lecture and hands-on practice, covers a single information resource. Grades are based on classroom participation; homework assignments; and a final project. The project, chosen by the student, is an oral presentation and a web site presenting the information resources best suited to his/her topic. My research interests involve how engineering students conduct research and in designing classroom and web-based instruction to enhance their information seeking strategies.
Poor Mothers and Habits of Hiding: Participatory Methods in Poverty Research

Poor mothers have long-standing habits of hiding their lives in response to punitive authorities and stigma. We identify practices of hiding daily life, and we describe participatory research approaches for and ethical concerns in learning more about poor women's critical insights and survival strategies.
Indentation‐Precracking and Double‐Torsion Methods for Measuring Fracture Mechanics Parameters in Hot‐Pressed Si3N4

The two widely used test methods, the indentation-induced flaw (IIF) and the double-torsion (DT), for measuring fracture mechanics parameters were directly compared using a commercial hot-pressed Si3N4. The IIF method is simple for estimating the inherent flaw size of the as-received material and in revealing the qualitative nature of slow crack growth as a function of temperature and strain rate. The critical stress intensity factor, Kic, for catastrophic failure at 20°C was 3.5 and 4.1 MN/m3/2 using IIF and DT methods, respectively. Crack velocities can be measured with greater accuracy using the DT method.
Hyponatremia and hypoglycemia in acute Sheehan's syndrome.

We report the case of a 23-year-old Saudi Arabian woman who presented to the medical intensive care unit with severe hyponatremia and hypoglycemia following a Cesarean section delivery complicated by hemorrhage due to disseminated intravascular coagulopathy. She was treated successfully for adrenal insufficiency acutely, and was later discharged on hormone replacement therapy. To our knowledge, this is the first case report of acute Sheehan's syndrome presenting with both hyponatremia and suggestive hypoglycemia. Pituitary necrosis is an uncommon complication of peripartum hemorrhagic shock. Since the initial description by Sheehan in 1937, the incidence of the syndrome has gradually declined through improved management of hemodynamic complications leading to the infarction of the gland. There are many studies describing complications of late Sheehan's syndrome; however, relatively few contain descriptions of the acute phase. In addition, the diagnosis of this syndrome is often determined after resolution...
Mutations in ampG or ampD Affect Peptidoglycan Fragment Release from Neisseria gonorrhoeae

Neisseria gonorrhoeae releases peptidoglycan fragments during growth. The majority of the fragments released are peptidoglycan monomers, molecules known to increase pathogenesis through the induction of proinflammatory cytokines and responsible for the killing of ciliated epithelial cells. In other gram-negative bacteria such as Escherichia coli, these peptidoglycan fragments are efficiently degraded and recycled. Peptidoglycan fragments enter the cytoplasm from the periplasm via the AmpG permease. The amidase AmpD degrades peptidoglycan monomers by removing the disaccharide from the peptide. The disaccharide and the peptide are further degraded and are then used for new peptidoglycan synthesis or general metabolism. We examined the possibility that peptidoglycan fragment release by N. gonorrhoeae results from defects in peptidoglycan recycling. The deletion of ampG caused a large increase in peptidoglycan monomer release. Analysis of cytoplasmic material showed peptidoglycan fragments as recycling intermediates in the wild-type strain but absent from the ampG mutant. An ampD deletion reduced the release of all peptidoglycan fragments and nearly eliminated the release of free disaccharide. The ampD mutant also showed a large buildup of peptidoglycan monomers in the cytoplasm. The introduction of an ampG mutation in the ampD background restored peptidoglycan fragment release, indicating that events in the cytoplasm (metabolic or transcriptional regulation) affect peptidoglycan fragment release. The ampD mutant showed increased metabolism of exogenously added free disaccharide derived from peptidoglycan. These results demonstrate that N. gonorrhoeae has an active peptidoglycan recycling pathway and can regulate peptidoglycan fragment metabolism, dependent on the intracellular concentration of peptidoglycan fragments.
Neonatal outcomes in relation to timing of repeat cesarean delivery at term

The increasing rates of repeat cesarean delivery necessitate, more than ever, the need to time deliveries to optimize neonatal outcomes. A recent large multicenter cohort study demonstrated that, contrary to current recommendations, a high proportion of elective cesarean deliveries in the USA are performed before 39 weeks' gestation. These early deliveries are associated with a significant increase in several adverse neonatal events, including respiratory complications, treated hypoglycemia, newborn sepsis and admission to the neonatal intensive care unit. This, together with results of previous studies, supports the recommendation to delay elective delivery to 39 weeks' gestation. From the current data, it is uncertain whether delivery before 39 weeks' gestation with documented fetal lung maturity will prevent the increased neonatal morbidity.
RFDNA: A wireless authentication system on flexible substrates

The design and development of RFDNA, an RF authentication system consisting of wirelessly transmitting and receiving electromagnetic signals in the presence of a constellation of dense metals called certificates of authenticity that act as reflecting obstacles, has been performed [1]. The unique feature of this system is that the authentication is physical (hardware-based). Therefore, an integration process necessitates the manufacturing of certificates of authenticity to be durable and able to withstand normal wear and tear. In this system, one of the drawbacks has been the materials that have been used in the design. The materials for the readers have been designed on bulkier, non-conformable substrates, such as FR4. Additionally, the certificates of authenticity consisted of metal wires that have been densely placed into heated plastic that is hardened to maintain the wires' position. In order to realize a more practical implementation, a new class of certificates of authenticity and readers need to be manufactured on flexible substrates. This paper will focus on the design of a new antenna for an RFDNA reader on flexible substrates.
Optimal Adaptive Control—Contradiction in Terms or a Matter of Choosing the Right Cost Functional?

Approaching the problem of optimal adaptive control as ldquooptimal control made adaptive,rdquo namely, as a certainty equivalence combination of linear quadratic optimal control and standard parameter estimation, fails on two counts: numerical (as it requires a solution to a Riccati equation at each time step) and conceptual (as the combination actually does not possess any optimality property). In this note, we present a particular form of optimality achievable in Lyapunov-based adaptive control. State and control are subject to positive definite penalties, whereas the parameter estimation error is penalized through an exponential of its square, which means that no attempt is made to enforce the parameter convergence, but the estimation transients are penalized simultaneously with the state and control transients. The form of optimality we reveal here is different from our work in [Z. H. Li and M. Krstic, ldquoOptimal design of adaptive tracking controllers for nonlinear systems,rdquo Automatica, vol. 33, pp. 1459-1473, 1997] where only the terminal value of the parameter error was penalized. We present our optimality concept on a partial differential equation (PDE) example-boundary control of a particular parabolic PDE with an unknown reaction coefficient. Two technical ideas are central to the developments in the note: a nonquadratic Lyapunov function and a normalization in the Lyapunov-based update law. The optimal adaptive control problem is fundamentally nonlinear and we explore this aspect through several examples that highlight the interplay between the non-quadratic cost and value functions.
CONSMAG: knowledge representation based upon consensus for multiple agents

A multiagent system designed to observe and remember patterns of cooccurrences in an open, dynamic system is described. The agents are organized according to function, with the low-level agents storing observed cooccurrences of key concepts or events in memory until being recycled for further service, thus simulating fixed short-term memory. The mid-level agents retain a short history (the length of this history is determined by the number of low-level agents available) of cooccurrence phenomena. The high-level executive agent computes three different, related associative networks as a graphical representation of the cooccurrences recorded by means of cumulative consensus of the mid-level agents and responds to queries. Thus the CONSMAG system effects a transformation from episodic memory to a class of associative networks representative of semantic memory. This learning paradigm supports cost estimates for learning any given associative network, including modification of one network into another, to simulate a novice becoming an expert.
Macroscopic stiffening of embryonic tissues via microtubules, RhoGEF and the assembly of contractile bundles of actomyosin

During morphogenesis, forces generated by cells are coordinated and channeled by the viscoelastic properties of the embryo. Microtubules and F-actin are considered to be two of the most important structural elements within living cells accounting for both force production and mechanical stiffness. In this paper, we investigate the contribution of microtubules to the stiffness of converging and extending dorsal tissues in Xenopus laevis embryos using cell biological, biophysical and embryological techniques. Surprisingly, we discovered that depolymerizing microtubules stiffens embryonic tissues by three- to fourfold. We attribute tissue stiffening to Xlfc, a previously identified RhoGEF, which binds microtubules and regulates the actomyosin cytoskeleton. Combining drug treatments and Xlfc activation and knockdown lead us to the conclusion that mechanical properties of tissues such as viscoelasticity can be regulated through RhoGTPase pathways and rule out a direct contribution of microtubules to tissue stiffness in the frog embryo. We can rescue nocodazole-induced stiffening with drugs that reduce actomyosin contractility and can partially rescue morphogenetic defects that affect stiffened embryos. We support these conclusions with a multi-scale analysis of cytoskeletal dynamics, tissue-scale traction and measurements of tissue stiffness to separate the role of microtubules from RhoGEF activation. These findings suggest a re-evaluation of the effects of nocodazole and increased focus on the role of Rho family GTPases as regulators of the mechanical properties of cells and their mechanical interactions with surrounding tissues.
Problems with wavefront aberrations applied to refractive surgery: developing standards

Refractive surgery is evolving rapidly. A recent development uses wavefront aberration information to improve the surgical outcome. Before the wavefront information can be used effectively a number of problems must first be resolved. One of the main concerns is the presence of halos during night driving conditions. It seems clear that this problem occurs when the pupil is large enough to overlap the ablation transition zone. Several questions associated with the transition zone are examined. Shape descriptors to characterize the transition zone are discussed. Better ways of quantitatively characterizing the transition zone and predicting its properties are needed to help specify the ablation. Many of the issues associated with improving refractive surgery can be addressed by establishing a standards committee that includes basic researchers and clinicians. This committee can become a forum for developing techniques to assess visual outcomes, it can make recommendations for developing a database that would allow researchers to compare the intended outcome of ablation with the actual outcome. In order for this enterprise to be successful increased openness about surgery parameters and surgery outcome would be helpful.
Delivery of interferon alpha using a novel Cox2-controlled adenovirus for pancreatic cancer therapy.

Background Combination therapy with interferon alpha (IFN) is correlated with improved survival in patients with pancreatic ductal adenocarcinoma (PDAc) but frequently presents side effects. We designed a novel targeted adenovirus with replication restricted to cyclooxygenase 2 (Cox2)-overexpressing PDAcs and hypothesize that the locally delivered therapeutic gene IFN can augment oncolytic effects while minimizing systemic toxicity. Methods IFN-expressing vectors were tested in vitro with the use of 4 PDAc cell lines with cytocidal effect measured by crystal violet and colorimetrically and IFN production assayed by ELISA. Cox2 promoter activity was checked by a luciferase reporter assay. In vivo, subcutaneous tumor xenografts with 2 PDAc cell lines in nude mice were treated with a single intratumoral viral dose. Results All PDAc cell lines were Cox2-positive. Oncolysis from the novel Cox2-controlled virus was comparable or superior to Adwt, the wild-type virus without safety features. The absence of cytocidal effect in Cox2-negative cells with the novel virus indicated cancer specificity. In vivo, stronger tumor suppression from the novel virus was seen when compared with nonreplicating IFN-expressing vectors. Conclusion We demonstrated the potent therapeutic effects of a novel tumor-specific conditionally replicative IFN-expressing adenovirus. With potential to locally deliver IFN and avoid systemic toxicity, this strategy may therefore expand the application of this robust and promising therapy.
Design of low-Gm transconductors using varactor-based degeneration and linearization technique

Low-Gm transconductors are useful for designing low-frequency-cutoff filters and amplifiers used in processing of biomedical signals. However, designing fully integrated low-Gm transconductors presents a challenge due to limitations on the size of on-chip capacitors and resistors and due to requirements on the signal dynamic range and the linearity of the transconductor. In this paper we propose a novel method for designing low-Gm transconductors using a varactor-based degeneration and linearization technique. The technique uses negative feedback where a varactor changes the capacitance of a floating-gate to compensate for the change in the input voltage. This results in the degeneration of the transconductance and a differential configuration of the input stage linearizes and enhances the dynamic range of the transconductor. We verify and characterize the proposed approach using measurement results obtained from prototypes fabricated in a 0.5-μm CMOS process.
The Role of Tariffs in Protecting Global Environmental Commons

The aim of this chapter is to set out and discuss the theoretical considerations that led to the claim that successful combat of degradation of global environmental commons may require the use of trade instruments. Furthermore, we raise open issues regarding eco-tariffs to protect global environmental commons which shall be addressed in chapters 8, 9 and 10.