cssi/SciSciGPT-SciSciNet huggingface dataset:
Infiltrative hepatocellular carcinoma: Comparison of MRI sequences for lesion conspicuity

Aim To characterize the magnetic resonance imaging (MRI) features of infiltrative hepatocellular carcinoma (I-HCC), with emphasis on its relative conspicuity on different sequences. Materials and methods Nineteen patients exhibiting HCC with non-mass-like appearance and ill-defined margins, and who died within 1 year following diagnosis of I-HCC, were included. For each sequence, two observers independently assessed the lesion's signal intensity relative to benign liver as well as subjective visual conspicuity. The observers also selected the sequence exhibiting the greatest visual conspicuity. A separate radiologist placed regions of interest to measure tumour-to-liver contrast for each lesion. Tumour size and clinical features were also assessed. Results Eighteen of the 19 patients exhibited central portal vein tumour thrombus; eight of the 19 patients had metastatic disease. All I-HCC measured over 5 cm. The two observers identified hyperintensity on T2-weighted imaging (WI) in 19 and 19 cases, hyperintensity on high b-value diffusion-weighted imaging (DWI) in 18 and 19 cases, arterial-phase hyperintensity in six and 10 cases, and venous-phase hypo-intensity in 17 and 16 cases. T2WI, DWI, and venous-phase images exhibited significantly greater subjective visual conspicuity than arterial-phase images for both observers (all p ≤ 0.040). Also, T2WI and DWI tended to exhibit greater tumour-to-liver contrast than arterial- and venous-phase images (all p ≤ 0.055). The arterial-phase was not selected as having greatest conspicuity for any case by either reader. Conclusion I-HCC is an aggressive form of HCC that is often less conspicuous on arterial-phase images than typical mass-forming HCC; T2WI and DWI may be more useful sequences for its diagnosis. Awareness of the distinct imaging features of I-HCC may be important for proper diagnosis.
Heterogeneity of genomes: measures and values

Abstract Genomic homogeneity is investigated for a broad base of DNA sequences in terms of dinucleotide relative abundance distances (abbreviated delta-distances) and of oligonucleotide compositional extremes. It is shown that delta-distances between different genomic sequences in the same species are low, only about 2 or 3 times the distance found in random DNA, and are generally smaller than the between-species delta-distances. Extremes in short oligonucleotides include underrepresentation of TpA and overrepresentation of GpC in most temperate bacteriophage sequences; underrepresentation of CTAG in most eubacterial genomes; underrepresentation of GATC in most bacteriophage; CpG suppression in vertebrates, in all animal mitochondrial genomes, and in many thermophilic bacterial sequences; and overrepresentation of GpG/CpC in all animal mitochondrial sets and chloroplast genomes. Interpretations center on DNA structures (dinucleotide stacking energies, DNA curvature and superhelicity, nucleosome organization), context-dependent mutational events, methylation effects, and processes of replication and repair.
GUEST EDITOR'S INTRODUCTION: Towards a Research Agenda for Pacific Rim Cities

This paper outlines three fundamental reasons underlying the need for more active communication between sectors (private, public and academic) and between urban centers in the Pacific Rim. First, the public and private sectors must, by virtue of their raisons d'etre, operate at close quarters. Secondly, the context in which urban development takes place is increasingly complex. This suggests a role for scholars in helping to inform the debate on urban development processes. Finally, many cities in the Pacific Rim region are increasingly bound to one another through flows of population, capital, information and trade. The key to understanding the evolution of individual urban areas within this region may well be through increased knowledge of the network as a whole.
Biosynthesis of uridine diphosphate d-xylose V. UDP-d-glucuronate and UDP-d-galacturonate carboxy-lyase of Ampullariella digitata

Abstract Partially purified sonic extract of Ampullariella digitata strain 399 converted UDPGlcUA or UDPGalUA to a mixture of UDPGalUA, UDPGlcUA, UDPXyl and UDPAra. However, the extract did not catalyze the reaction: UDPXyl ⇄ UDPAra. In the presence of unlabeled UDPXyl, UDP-[ 14 C]GlcUA yielded only UDP-[ 14 C]Xyl, and UDP-[ 14 C]GalUA yielded only UDP-[ 14 C]Ara. The partially purified sonic extract was further fractionated by chromatography on Sephadex G-75 to yield a fraction containing NAD-dependent UDPGlcUA carboxy-lyase, and UDPGalUA 4-epimerase, but no UDPGalUA carboxy-lyase. In the presence of unlabeled UDPXyl, this fraction produced only UDP-[ 14 C]Xyl from UDP-[ 14 C]GlcUA. Thus UDPXyl inhibits UDPG-alUA 4-epimerase but not UDPGlcUA- (or UDPGalUA-) carboxy-lyase. The results further indicate that A. digitata contains the following enzymes: UDPGalUA 4-epimerase, UDPGlcUA carboxy-lyase, and UDPGalUA carboxy-lyase. UDPGalUA carboxy-lyase has not been demonstrated previously. Although UDPGlcUA carboxylyase is known in higher organisms and blue-green algae, it has not been demonstrated previously in bacteria.
Demystifying brain penetration in central nervous system drug discovery. Miniperspective.

This Perspective provides important concepts about the blood–brain barrier (BBB) in drug discovery and how they should be applied effectively in designing successful CNS drugs. Key parameters for brain penetration are discussed, including unbound brain concentration, unbound brain-to-plasma ratio, BBB permeability, fraction unbound in brain and plasma, and transporters. Results from a retrospective analysis of 32 Pfizer CNS clinical drug candidates are described. Frequently encountered misconceptions about brain penetration in drug discovery programs are clarified. Strategies and guidance are provided to enhance or minimize brain exposure for CNS or peripheral targets, respectively. Recommendations for screening methodologies and a cascade in assessing brain penetration potential are presented.
Ab initio quantum-mechanical calculations on trifluoromethylamine

Extensive ab initio molecular-orbital calculations were carried out on trifluoromethylamine (TFM) to elucidate changes in geometry and electronic structure upon fluorination. The calculations show that the decomposition of CF3NH2 is slightly endoenergetic, and the heats of atomization of CF3NH2 and CH3NH2 show decreased stability of the species upon fluorination. Characteristic of CF3NH2 is a highly polar, strong, short CN bond. More limited calculations were carried out on CF3OH and CH3OH, and the electronic structure of CF3OH is found to be generally similar to that of CF3NH2. The reduced basicity of the fluorinated amine cannot be ascribed to the inductive effect; the enhanced acidity of the fluorinated alcohol reflects the weakening of the OH bond. No evidence leads to a confirmation of the existence of nitrogen–fluorine hyperconjugation in the fluorinated amine.
Ca2+ Release by inositol trisphosphate from Ca2+-transporting microsomes derived from uterine sarcoplasmic reticulum

Microsomes derived from pregnant uterine sarcoplasmic reticulum, isolated by differential and sucrose density gradient centrifugation, accumulates Ca2+ in the presence of ATP. Inositol trisphosphate caused release of this Ca2+, in a dose dependent manner. 40% of the Ca2+ that can be released by the ionophore A23187 was released by 5 uM inositol trisphosphate. Removal of Mg by EDTA prior to addition of inositol trisphosphate did not change the course of Ca2+ release. These results indicate that by mobilizing intracellular Ca2+, inositol trisphosphate may be the link between hormonal stimuli and smooth muscle contraction.
A Collaborative Approach to Defining Neonatal Therapy

Abstract The purpose of this article is to provide a reference for occupational therapists, physical therapists, and speech-language pathologists on a shared definition of neonatal therapy. This article will further outline the collaborative efforts, process and recommendations of a multidisciplinary team of neonatal occupational therapists, physical therapists, and speech-language pathologists, who participated in an inaugural meeting on February 12, 2012, as part of the National Association of Neonatal Therapists (NANT). One of the first goals of the NANT Professional Collaborative was to define the practice of neonatal therapy. To move forward as one group, two questions were considered: first, who are we as neonatal therapists and, second, what is neonatal therapy? The American Occupational Therapy Association, American Physical Therapy Association, and the American Speech and Hearing Association have all published three separate articles outlining skills, knowledge, and scope of practice. However, all three disciplines share common ground in the neonatal intensive care unit, and the NANT Professional Collaborative took on the task of creating one definition that could be shared by all.
Reiki Brief Report: Using Reiki to Reduce Stress Levels in a Nine-Year-Old Child

A nine-year-old female with a history of perinatal stroke, seizures, and type-I diabetes was seen for six weeks of Reiki to determine the effects of Reiki on relaxation, and in turn, the prevention of future seizures. The secondary and tertiary aims were to determine the effects of Reiki on sleep patterns and the stress levels of the mother. There was a decrease in stress in both the child and the mother, as measured by a modified Perceived Stress Scale and a Perceived Stress Scale, respectively. There was no change in the child's overall sense of well-being, as measured by a global questionnaire. There was a positive change in sleep patterns on 33.3% of the nights during which the study occurred, as reported on a sleep log kept by the mother. The child and the Reiki Master (a Reiki practitioner who has completed all three levels of Reiki certification training and trains and certifies individuals in the practice of Reiki as well as provides Reiki to individuals) experienced warmth and tingling sensations on the same area of the child during the Reiki sessions. The child relaxed within the first five to seven minutes of each session as reported by the Reiki Master. There were no reports of seizures during this study. Reiki may be a useful adjunct for children with increased stress levels and sleep disturbances secondary to their medical condition. Further research is warranted to evaluate the use of Reiki in children, particularly with a large sample size, and to evaluate the long-term use of Reiki and its effects on adequate sleep.
Information-sharing in public organizations: A literature review of interpersonal, intra-organizational and inter-organizational success factors

Abstract Information sharing is considered an important approach to increasing organizational efficiency and performance. With advances in information and communication technology, sharing information across organizations has become more feasible. In the public sector, government agencies are also aware of the importance of information sharing for addressing policy issues such as anti-terrorism and public health. However, information sharing can be a complex task. Identifying factors that influence information sharing is critical. In the literature, research in information sharing focuses on the interpersonal, intra-organizational, and inter-organizational levels. This paper reviews the current information-sharing research, discusses the factors affecting information sharing at the three levels, and provides summative frameworks. These frameworks provide a means to discover future research opportunities, and a systematic way for practitioners to identify key factors involved in successful information sharing.
Master-detail clustering using merged indexes

Merged indexes are B-trees that contain multiple traditional indexes and interleave their records based on a common sort order. In relational databases, merged indexes implement ‘‘master-detail clustering’’ of related records, e.g., orders and order details. Thus, merged indexes shift de-normalization from the logical level of tables and rows to the physical level of indexes and records, which is a much more appropriate place for it. For object-oriented applications, clustering can reduce the I/O cost for joining rows in related tables to a fraction compared to traditional indexes, with additional beneficial effects on buffer pool requirements.
Reduction of transiently expressed acetylcholinesterase activity in developing thalamocortical projections does not affect the mature pattern of basal forebrain projections to visual cortex

Abstract Experiments tested the hypothesis that acetylcholinesterase (AChE) activity, expressed transiently in developing thalamocortical sprojections, serves to limit the growth of basal forebrain cholinergic projections into thalamocortical recipient zones. Newborn rats were subjected to enucleation, a procedure that eliminates transient AChE activity in developing visual cortex. After 3–8 weeks survival, AChE histochemical techniques revealed no alteration in the pattern of AChE positive basal forebrain axons in visual cortex. These data indicate that transient AChE activity in developing sensory cortex does not limit ingrowth of basal forebrain cholinergic axons.
Overdrive Pacing From Downstream Sites on Multielectrode Catheters to Rapidly Detect Fusion and to Diagnose Macroreentrant Atrial Arrhythmias

Background—Entrainment criteria for macroreentrant arrhythmias are based on detecting fusion between tachycardia and paced wavefronts, but this is often difficult for atrial tachycardias (AT) after ablation of atrial fibrillation. Methods and Results—With the use of a multipolar catheter, pacing was performed from electrodes within the coronary sinus showing activation later than adjacent electrodes (downstream overdrive pacing) during 66 ATs in 62 patients: 20 cavotricuspid isthmus–dependent ATs, 20 perimitral ATs, 13 focal ATs with sequential coronary sinus activation, and 13 other macroreentrant left atrial ATs. The paced cycle length was 10 to 30 milliseconds below the tachycardia cycle length (TCL), and activation at the neighboring upstream electrodes was assessed. Downstream overdrive pacing at 48 sites close to a macroreentrant circuit (PPI−TCL <40 milliseconds, where PPI is postpacing interval) produced constant fusion demonstrated by a long stimulus to upstream atrial electrogram interval (S-Au)...
Discovery of Small Molecule Integrin αvβ3 Antagonists as Novel Anticancer Agents

Integrin alphavbeta3 has been implicated in multiple aspects of tumor progression and metastasis. Many tumors have high expression of alphavbeta3 that correlates with tumor progression. Therefore, alphavbeta3 receptor is an excellent target for drug design and delivery. We have discovered a series of novel alphavbeta3 antagonists utilizing common feature pharmacophore models. Upon validation using a database of known alphavbeta3 receptor antagonists, a highly discriminative pharmacophore model was used as a 3D query. A search of a database of 600 000 compounds using the pharmacophore Hypo5 yielded 832 compounds. On the basis of structural novelty, 29 compounds were tested in alphavbeta3 receptor specific binding assay and four compounds showed excellent binding affinity. A limited SAR analysis on the active compound 26 resulted in the discovery of two compounds with nanomolar to subnanomolar binding affinity. These small-molecule compounds could be conjugated to paclitaxel for selective delivery to alphavbeta3 positive metastatic cancer cells.
The alleles at the E1 locus impact the expression pattern of two soybean FT -like genes shown to induce flowering in Arabidopsis

A small gene family of phosphatidyl ethanolamine-binding proteins (PEBP) has been shown to function as key regulators in flowering; in Arabidopsis thaliana the FT protein promotes flowering whilst the closely related TFL1 protein represses flowering. Control of flowering time in soybean [Glycine max (L.) Merrill] is important for geographic adaptation and maximizing yield. Soybean breeders have identified a series of loci, the E-genes, that control photoperiod-mediated flowering time, yet how these loci control flowering is poorly understood. The objectives of this study were to evaluate the expression of GmFT-like genes in the E1 near-isogenic line (NIL) background. Of the 20 closely related PEBP proteins in the soybean genome, ten are similar to the Arabidopsis FT protein. Expression analysis of these ten GmFT-like genes confirmed that only two are detectable in the conditions tested. Further analysis of these two genes in the E1 NILs grown under short-day (SD) and long-day (LD) conditions showed a diurnal expression and tissue specificity expression commensurate with soybean flowering time under SD and LD conditions, suggesting that these were good candidates for flowering induction in soybean. Arabidopsis ft mutant lines flowered early when transformed with the two soybean genes, suggesting that the soybean genes can complement the Arabidopsis FT function. Flowering time in E1 NILs is consistent with the differential expression of the two GmFT-like genes under SD and LD conditions, suggesting that the E1 locus, at least in part, impacts time to flowering through the regulation of soybean FT expression.
Impact of sickle cell disease and thalassemias in infants on birth outcomes

Abstract Objective The contribution of sickle cell disease (SCD) and other common thalassemias in infants to adverse birth outcomes is under-studied. We therefore sought to compare adverse birth outcomes in infants with and without hemoglobinopathy. Study design Retrospective cohort study utilizing a population-based dataset from Florida (1998–2007, n = 1,564,038). The primary outcomes were low birthweight (LBW), very low birthweight (VLBW), preterm birth (PTB), very preterm birth (VPTB) and small for gestational age (SGA). We used propensity scores to match infants with hemoglobinopathy to those without hemoglobinopathy on selected variables. To approximate relative risks, we generated adjusted odds ratios (AOR) and 95% confidence intervals (CI) from logistic regression models and accounted for the matched design using generalized estimating equations framework. Results Infants with SCD or thalassemia had a heightened risk for LBW (AOR = 1.58, 95% CI: 1.29–1.93), VLBW (AOR = 3.01, 95% CI: 2.12–4.25), PTB (AOR = 1.36, 95% CI: 1.12–1.65), VPTB (AOR = 2.70, 95% CI: 1.93–3.78), and neurological conditions (AOR = 2.04, 95% CI: 1.48–2.81) compared to infants without hemoglobinopathy. Conclusion Infants with SCD or thalassemia experience considerably higher risks for multiple infant morbidities. Our findings are potentially important in prenatal counseling, as well as for targeted care of affected pregnancies in the prenatal period.
ACCUMULATION AND FRACTIONATION OF COPPER, IRON, MANGANESE, AND ZINC IN CALCAREOUS SOILS AMENDED WITH COMPOSTS†

Amending soils with compost may lead to accumulation of metals and their fractions at various concentrations in the soil profile. The objectives of this study were to determine 1) the accumulation of Cu, Fe, Mn, and Zn with depth and 2) the distribution of water soluble, exchangeable, carbonate, Fe-Mn oxides, organic and residual forms of each metal in soils amended with MSW compost, co-compost, biosolids compost and inorganic fertilizer (as control). Total concentrations of Cu, Fe, Mn and Zn were concentrated in the 0-22 cm soil layer and scant in the rock layer. These metals were in the decreasing order of Fe >> Mn > Zn > or = Cu. Copper, Fe, and Zn were predominantly in the residual form followed by fractions associated with Fe-Mn oxides, carbonate, organic, exchangeable and water soluble in all treatments except MSW compost amended soil where the organic fraction was higher than the carbonate fraction. In fertilizer, co-compost and biosolids compost treated soils Mn concentrated mainly in the Fe-Mn oxides form followed by residual, carbonate, and organic forms whereas, in MSW compost treated soil the same pattern occurred except that Mn organic fraction was higher than that in the carbonate form. The MSW compost has a greater potential to be used as a soil amendment to supply plants with Cu, Mn and Zn than other treatments in calcareous soils of south Florida.
ANAESTHESIA FOR EMERGENCY CORONARY ARTERY SURGERY

The details of 60 patients scheduled for emergency coronary artery surgery are presented. Forty-two patients were categorized as having "impending" infarctions and 18 were operated on within 4 hours of sustaining acute myocardial infarctions. The patients presented with different haemodynamic disturbances and the selection of anaesthetic drugs was modified accordingly. We have found that conventional anaesthetic methods, conservatively applied, can be used safely in this group. The induction of anaesthesia and the increase in arterial oxygen tensions obtained by controlled ventilation produced an improvement in e.c.g. signs of ischaemia, and also reduced myocardial irritability. Circulatory complications were treated according to information obtained from simple monitoring techniques. The responsibility of the anaesthetist in postoperative care is emphasized and a regime of postoperative ventilatory management is described.
Serum insulin and growth hormone in lipoatrophic diabetes.

Abstract Hypersecretion of growth hormone has been suspected as a cause of the lipoatrophy and insulin resistance in lipoatrophic diabetes. Serum insulin and growth hormone studies were performed on three siblings with lipoatrophic diabetes to obtain information regarding the role of growth hormone in this syndrome; responses to the administration of glucose tolbutamide, and insulin were investigated. The subject with only mildly abnormal glucose tolerance had serum concentrations of immunoreactive insulin which were abnormally elevated after an oral glucose load, while the two patients with more severe diabetes had normal fasting insulin concentrations which failed to increase after glucose administration. After intravenous tolbutamide, there was an abnormally slow decline in the blood sugar in all three subjects as well as a subnormal rise in serum insulin in the patient with the most severe diabetes. All patients showed resistance to insulin given intravenously but insulin antibodies were not detected in their sera. The fasting serum immunoreactive growth hormone concentration was normal (
Hindered diffusion of synthetic polyelectrolytes in charged microporous membranes

Abstract To examine electrostatic effects on the diffusion of macromolecules in membranes, diffusivities of narrow molecular-size fractions of the polyelectrolytes ficoll sulfate and dextran sulfate were measured in polycarbonate track-etch membranes. Radius, number density, and surface charge density of membrane pores were determined from a combination of hydraulic permeability, glucose diffusion, and streaming potential measurements. Molecular charge and Stokes—Einstein radius for each macromolecule fraction were determined from free-solution electrophoretic mobility and diffusivity in a large pore radius membrane, D∞, respectively. As ionic strength was increased from 0.005 to 0.1 M, D∞ for ficoll sulfate remained constant while D∞ for dextran sulfate increased slightly (15-18%). Macromolecule diffusivities in small pore membranes, D, were much more sensitive to ionic strength. For membranes where the ratio of Stokes—Einstein radius to pore radius ranged from 0.08 to 0.29, D/D∞ for ficoll sulfate and dextran sulfate increased by factors ranging from 2.5 to 14 for the same increase in ionic strength. Recent theoretical results for electrostatic double layer interactions in hindered diffusion are in good quantitative agreement with these findings.
Role of electrospun fibre diameter and corresponding specific surface area (SSA) on cell attachment.

In order to develop scaffolds for tissue regeneration applications, it is important to develop an understanding of the kinetics of cell attachment as a function of scaffold geometry. In the present study, we investigated how the specific surface area of electrospun scaffolds affected cell attachment and spreading. Number of cells attached to the scaffold was measured by the relative intensity of a metabolic dye (MTS) and cell spreading was analysed for individual cells by measuring the area of projected F-actin cytoskeleton. We varied the fibre diameter to obtain a specific surface area distribution in the range 2.24–18.79 µm−1. In addition, we had one case where the scaffolds had beads in them and therefore had non-uniform fibres. For each of these different geometries, we varied the cell-seeding density (0.5–1 × 105) and the serum concentration (0–12%) over the first 8 h in an electrospun polycaprolactone NIH 3T3 fibroblast system. Cells on beaded scaffolds showed the lowest attachment and almost no F-actin spreading in all experiments indicating uniform fibre diameter is essential for electrospun scaffolds. For the uniform fibre scaffolds, cell attachment was a function of scaffold specific surface area (SSA) (18.79–2.24 µm−1) and followed two distinct trends: when scaffold SSA was 7.13 µm−1 there was a significant increase in cellular attachment rate with increasing SSA. This indicated that nanofibrous scaffolds increased cellular adhesion compared to microfibrous scaffolds. This phenomenon is true for serum concentrations of 7.5% and higher. For 5% and lower serum concentration, cell attachment is low and higher SSA fails to make a significant improvement in cell attachment. When cell attachment was investigated at a single-cell level by measuring the projected actin area, a similar trend was noted where the effect of higher SSA led to higher projected area for cells at 8 h. These results indicate that uniform electrospun scaffolds with SSA provide a faster cell attachment compared to lower SSA and beaded scaffolds. These results indicate that continuous electrospun nanofibrous scaffolds may be a good substrate for rapid tissue regeneration. Copyright © 2009 John Wiley & Sons, Ltd.
A skill-based approach to human resource management

Abstract Skill-based human resource management has many advantages over the job-based approach, and can provide firms with a new source of competitive advantage. Edward Lawler and Gerald Ledford explore all aspects of this emerging new model of HRM and, in particular, review the strategic, structural and cultural conditions in organizations which favour its implementation. Modern economies are giving rise to an environment in which these conditions are flourishing and hence skill-based HRM seems more relevant. As leading firms adopt the model and gain in competitive advantage, others will be obliged to follow.
Nonpalpable Intratesticular Masses Detected Sonographically

AbstractPurpose: There is controversy concerning the implications of impalpable testicular masses. We examine the sonographic findings and pathology of such tumors.Materials and Methods: Between 1985 and 1994, 3,019 scrotal ultrasound studies were performed for various indications and 15 impalpable masses were discovered.Results: Pathological study revealed 5 seminomas, 6 nonseminomas, 2 “burned-out” tumors, 1 lipoma and 1 granuloma.Conclusions: Impalpable intratesticular masses are likely to be malignant. Any young man with retroperitoneal or visceral masses should undergo scrotal ultrasound. A testicular mass is likely to be the primary cancer but it may be regressed. Persistent scrotal pain may be a presentation of malignancy and should be evaluated with ultrasound.
Peroxidases in tobacco abscission zone tissue. VI. Ultrastructural localization in plasmodesmata during ethylene-induced abscission.

The ultrastructural localization of peroxidases, during ethylene-induced abscission, in flower pedicels of Nicotiana tabacum L. cv. ‘Little Turkish’, has been investigated. Peroxidase activity has been localized in the plasmodesmata of abscission zone tissue that had been fixed in glutaraldehyde and subsequently incubated in diaminobenzidine (DAB) medium with post-fixation in osmium tetroxide. Preincubation of tissue in potassium cyanide, prior to incubation in DAB medium containing the inhibitor, demonstrates a significant reduction in DAB staining. Incubation of tissue in aminotriazole (an inhibitor of catalase activity), prior to incubation in DAB medium containing the inhibitor, does not inhibit the peroxidase activity in plasmodesmata incubated in DAB medium; however, aminothiazole does inhibit catalase present in the microbodies of DAB incubated tissue. It is suggested that proliferating plasmodesmata, in response to ethylene treatment, exhibit enhanced peroxidase activity and allow for the increased mobilization of peroxidase to the middle lamellar areas of the cell walls of abscising cells.
Studies on chemically induced dominant lethality III. Cytogenetic analysis of tem-effects on maturing dictyate mouse oocytes

A comparative cytogenetic study was done on metaphase-I oocytes and first cleavage mitoses following treatment of young mature female mice with triethylenemelamine (TEM). The ova were collected at intervals ranging from 12 h to 10.5 days after single intraperitoneal injection of TEM. Very few structural aberrations were seen in the metaphase-I cells after TEM treatment. There was, however, a very clear effect on the female genome when first cleavage mitoses were analyzed. The aberrations seen were principally chromatid deletions and interchanges, and their frequency varied with dose and the time between treatment and mating.
Parametric evaluation of the development of sensitization to the effects of morphine on locomotor activity.

Abstract Animals repeatedly administered drugs of abuse often become more sensitive to their effects. It has been proposed that this behavioral sensitization may serve as a useful model for changes that may underlie the etiology and maintenance of drug-seeking behavior. This study was designed to determine systematically some of the conditions of drug exposure under which sensitization occurs to morphine-induced stimulation of locomotor activity. Groups of rats ( n =8 per group) were exposed to a regimen of intermittent morphine or saline injections for 1–4 days and tested at later time points with morphine or saline. The amount of behavioral sensitization observed was related to the number of drug exposures, but not to the dose of morphine used during drug exposures. Sensitization to morphine persisted for as long as 3 months and was completely blocked when naltrexone was administered with the test dose of morphine after the final morphine exposure. Administration of naltrexone with morphine during the exposure regimen did not alter the development of behavioral sensitization. These results indicate a robust behavioral sensitization to morphine that appears to be influenced in an orderly manner within a narrow window of the drug exposure conditions.
Physiology: is brain sympathetic to bone?

The fat-derived hormone leptin is best known for its effects on weight. But it also influences bone density, and new work reveals a role for the sympathetic nervous system in mediating this effect.
Effect of incident shock wave strength on the decay of Richtmyer–Meshkov instability-introduced perturbations in the refracted shock wave

The effect of incident shock wave strength on the decay of interface introduced perturbations in the refracted shock wave was studied by performing 20 different simulations with varying incident shock wave Mach numbers (M ~ 1.1− 3.5). The analysis showed that the amplitude decay can be represented as a power law model shown in Eq.7, where A is the average amplitude of perturbations (cm), B is the base constant (cm−(E−1), S is the distance travelled by the refracted shockwave (cm), and E is the power constant. The proposed model fits the data well for low incident Mach numbers, while at higher mach numbers the presence of large and irregular late time oscillations of the perturbation amplitude makes it hard for the power law to fit as effectively. When the coefficients from the power law decay model are plotted versus Mach number, a distinct transition region can be seen. This region is likely to result from the transition of the post-shock heavy gas velocity from subsonic to supersonic range in the lab frame. This region separates the data into a high and low Mach number region. Correlations for the power law coefficients to the incident shock Mach number are reported for the high and low Mach number regions. It is shown that perturbations in the refracted shock wave persist even at late times for high incident Mach numbers.
A finite algorithm for monotone regression and the application of its principle to the aggregation of ranks and indifference curve fitting

Monotone regression makes optimal consistent adjusted value assignments to ordinal dependent data, or monotonically adjusts ratio-level-dependent variable data to achieve the best possible agreement with an explanatory linear (in the sense of parameters) model. Thus, for example, as a tool for building group or individual multi-attribute value (MAV) functions, it partially obviates the need to prespecify a particular MAV function class. The height of the unknown MAV function at each comparison bundle is determined along with the other model parameters.
Effect of inflammatory cytokines on the adherence of tumor cells to endothelium in a murine model.

Abstract We have demonstrated that pretreatment of mouse brain microvascular endothelial cells (MBE) with tumor necrosis factor-α (TNF), IL-1, or LPS augmented the binding of P815 mastocytoma cells in vitro . The effect of these agents was dose and time dependent. PMA was able to mimic the influence of these factors to a limited degree. The effect of TNF on endothelium was accompanied by the appearance of changes in the expression of proteins isolated from endothelial cell membranes. The adherence of tumor cells to endothelium was not inhibited by RGD-containing peptides but could be decreased by preincubation of endothelium with high concentrations of FCS. Our data suggest that cytokines regulate the synthesis of endothelial adhesion proteins which may be involved in tumor cell adherence leading to metastasis. These result raise the possibility that cytokines may exert paradoxical effects in vivo , i.e., a cytotoxic effect that reduces tumor mass accompanied by a metastasis-enhancing effect that actually promotes dissemination of the remaining tumor cells. Definition of the molecular events involved in tumor cell-endothelial cell interactions may lead to strategies for minimizing the latter effect in therapeutic settings.
In Search of the Holy Grail for Drosophila TRP

Activation of the archetypal Transient Receptor Potential (TRP) channel, which is essential for Drosophila phototransduction, depends on a phospholipase C (PLC). However, the precise mechanism linking PLC to the gating of TRP has been elusive. In this issue of Neuron , Leung et al. provide compelling evidence that a diacylglycerol (DAG) lipase (INAE), acting downstream of the PLC, is essential for opening TRP. These results strongly support the model that a DAG metabolite is critical for TRP activation and suggest that mammalian DAG lipases may play similar roles.
Experimental study of whole core thermal-hydraulic phenomena in EBR-II

Abstract In the analysis of core-wide temperature distributions in a liquid-metal-cooled fast breeder reactor (LMFBR) under both normal and abnormal operating conditions, it is commonly assumed that there is little, if any, thermal interaction between adjacent subassemblies. Since intersubassembly heat transfer tends to reduce the transverse temperature gradients in a reactor, thereby ameliorating the effects of local overheating, this assumption is conservative. In order to assess the importance of this effect as well as of flow redistribution in a reactor core, an experimental study was conducted in EBR-II covering a wide range of operating power and flow conditions, including both forced and natural convection. The results of this study indicate that radial heat transfer and flow redistribution are important mechanisms in the thermal-hydraulics of LMFBR cores, especially at low flow rates.
Decentralized adaptive control for a class of large-scale systems with multiple delays in the interconnections

In this paper, we consider the decentralized stabilization problem of a class of large-scale systems subject to uncertain parameters and multiple time-varying delays in the interconnections and non-linear inputs. The interconnection matrices are subject to perturbations whose bounds are unknown. Decentralized memoryless adaptive controllers are synthesized within an LMI framework to guarantee that the state trajectories of the large-scale system are uniformly exponentially convergent towards a ball with any prespecified exponential convergence rate. The problem is formulated as an optimization problem with LMI constraints. Finally, an example is included to illustrate the results developed in this paper. Copyright © 2004 John Wiley & Sons, Ltd.
Certification testing at the National Wind Technology Center

The International Electrotechnical Commission is developing a new standard that defines power performance measurement techniques. The standard will provide the basis for international recognition of a wind turbine`s performance primarily for certification, but also for qualification for tax and investment incentives, and for contracts. According to the standard, the power performance characteristics are defined by a measured power curve and by projections of annual energy production for a range of wind conditions. The National Wind Technology Center (NWTC) has adopted these power performance measurement techniques. This paper reviews the results of the NWTC`s first test conducted under the new protocol on the Atlantic Orient Corporation`s AOC 15/50 wind turbine at the NWTC. The test required collecting sufficient data to establish a statistically significant database over a range of wind speeds and conditions. From the data, the power curve was calculated. Then the results from a site calibration procedure determined the flow distortion between winds measured at the turbine location and those measured at the meteorological tower. Finally, this paper discusses the uncertainty analysis that was performed in accordance with the standard. Use of these procedures resulted in the definition of the AOC 15/50`s power curve within about 3 kW.
Photonics technology and the implementation into solid state phased arrays

The benefits and limitations of photonic interconnections in solid state phased arrays are discussed. Direct and indirect modulated links are analyzed with respect to SNR, intermodulation distortion, noise figure, and clutter spreading due to nonlinearities. An advanced radar architecture having a number of fiber optic links is described.
Crystallographic and biochemical analyses of the metal-free Haemophilus influenzae Fe3+-binding protein

The crystal structure of the iron-free (apo) form of the Haemophilus influenzae Fe(3+)-binding protein (hFbp) has been determined to 1.75 A resolution. Information from this structure complements that derived from the holo structure with respect to the delineation of the process of iron binding and release. A 21 degrees rotation separates the two structural domains when the apo form is compared with the holo conformer, indicating that upon release of iron, the protein undergoes a change in conformation by bending about the central beta-sheet hinge. A surprising finding in the apo-hFbp structure was that the ternary binding site anion, observed in the crystals as phosphate, remained bound. In solution, apo-hFbp bound phosphate with an affinity K(d) of 2.3 x 10(-3) M. The presence of this ternary binding site anion appears to arrange the C-terminal iron-binding residues conducive to complementary binding to Fe(3+), while residues in the N-terminal binding domain must undergo induced fit to accommodate the Fe(3+) ligand. These observations suggest a binding process, the first step of which is the binding of a synergistic anion such as phosphate to the C-terminal domain. Next, iron binds to the preordered half-site on the C-terminal domain. Finally, the presence of iron organizes the N-terminal half-site and closes the interdomain hinge. The use of the synergistic anion and this iron binding process results in an extremely high affinity of the Fe(3+)-binding proteins for Fe(3+) (nFbp K'(eff) = 2.4 x 10(18) M(-1)). This high-affinity ligand binding process is unique among the family of bacterial periplasmic binding proteins and has interesting implications in the mechanism of iron removal from the Fe(3+)-binding proteins during FbpABC-mediated iron transport across the cytoplasmic membrane.
Scaling laws for the movement of people between locations in a large city.

Large scale simulations of the movements of people in a ‘‘virtual’’ city and their analyses are used to generate insights into understanding the dynamic processes that depend on the interactions between people. Models, based on these interactions, can be used in optimizing traffic flow, slowing the spread of infectious diseases, or predicting the change in cell phone usage in a disaster. We analyzed cumulative and aggregated data generated from the simulated movements of 1.6310 6 individuals in a computer ~pseudo-agent-based! model during a typical day in Portland, Oregon. This city is mapped into a graph with 181 206 nodes representing physical locations such as buildings. Connecting edges model individual’s flow between nodes. Edge weights are constructed from the daily traffic of individuals moving between locations. The number of edges leaving a node ~out-degree!, the edge weights ~out-traffic!, and the edge weights per location ~total out-traffic! are fitted well by power-law distributions. The power-law distributions also fit subgraphs based on work, school, and social/recreational activities. The resulting weighted graph is a ‘‘small world’’ and has scaling laws consistent with an underlying hierarchical structure. We also explore the time evolution of the largest connected component and the distribution of the component sizes. We observe a strong linear correlation between the out-degree and total out-traffic distributions and significant levels of clustering. We discuss how these network features can be used to characterize social networks and their relationship to dynamic processes.
Enhanced autophagy blocks angiogenesis via degradation of gastrin-releasing peptide in neuroblastoma cells

Neuroblastoma is characterized by florid vascularization leading to rapid tumor dissemination to distant organs; angiogenesis contributes to tumor progression and poor clinical outcomes. We have previously demonstrated an increased expression of gastrin-releasing peptide (GRP) and its receptor, GRPR, in neuroblastoma and that GRP activates the PI3K-AKT pathway as a proangiogenic factor during tumor progression. Interestingly, AKT activation phosphorylates MTOR, a critical negative regulator of autophagy, a cellular process involved in the degradation of key proteins. We hypothesize that inhibition of GRPR enhances autophagy-mediated degradation of GRP and subsequent inhibition of angiogenesis in neuroblastoma. Here, we demonstrated a novel phenomenon where targeting GRPR using shRNA or a specific antagonist, RC-3095, decreased GRP secretion by neuroblastoma cells and tubule formation by endothelial cells in vitro. Furthermore, shGRPR or RC-3095 treatment enhanced expression of proautophagic proteins in hu...
Black-White Differences in Cigarette Smoking Uptake: Progression from Adolescent Experimentation to Regular Use☆☆☆★

Background. More U.S. adolescents and young adults have initiated cigarette smoking in recent years. Blacks have been less likely than whites to start smoking, and the gap has widened recently. Reasons accounting for this large black-white difference remain unclear. Methods. A multiple logistic regression analysis was performed using a cohort of 2,467 adolescent smoking experimenters ages 11–18, within the 1989–1993 Teenage Attitudes and Practices Survey, a nationally representative survey. Results. Among experimenters (1989), 25.7% of whites and 10.3% of blacks had progressed to current smoking (1993). The unadjusted odds ratio (OR) of progression for blacks (vs whites) was 0.33 [95% confidence interval (CI) 0.23, 0.48]. Adjustment for factors significantly predictive of progression (most parsimonious model) modified the black-white OR to 0.36 (CI 0.24, 0.55), while the full model yielded a black-white OR of 0.39 (CI0.24, 0.66). Conclusions. The observed black-white difference in smoking progression was only partly explained by the factors evaluated, and some additional factor(s) must be important. Understanding the black-white difference in the progression from experimentation to current smoking may help prevent uptake among all adolescents.
Chromatographic repair of storage-inactivated dihydrofolate reductase from Diplococcus pneumoniae.

Chromatography of dihydrofolate reductase from D. pneumoniae on DEAE-cel-lulose separated two active components from crude cell-free preparations. One component was found only after the extract was subjected to a period of storage at −20 ° and was distinguishable from the normal component by a greater heat sensitivity and a unique elution behavior confirmed by rechromatography. Other data are presented which suggest that the new component originated by Chromatographic “repair” of storage-inactivated enzyme.
Importance of ischemic and viable myocardium for patients with chronic ischemic mitral regurgitation and left ventricular dysfunction.

The objective of this investigation is to determine the importance of ischemic viable myocardium for clinical outcomes in patients with severe chronic ischemic mitral regurgitation and severe left ventricular dysfunction undergoing surgical correction of mitral regurgitation. The study included 54 patients with left ventricular ejection fraction of 27 ± 9%. Positron emission tomography was performed preoperatively for the identification of ischemic viable myocardium. The patients with a large amount of ischemic viable myocardium (≥5 segments) had significantly lower 6-month mortality rates than those with less viable myocardium (0 to 4 segments) after the surgery.
The gain of two chloroplast tRNA introns marks the green algal ancestors of land plants

THE relationship of green algae to land plants has greatly interested botanists for more than a century. In recent years, several characters, particularly ultrastructural ones, have been used to define a green algal group (Charophyceae) from which land plants are thought to have arisen (refs 1–3, but see ref. 4). Here we provide the first molecular genetic evidence in support of the charophycean origin of land plants. Group II introns have previously been found in both the tRNAAla and tRNAIle genes of all land plant chloroplast DNAs examined, whereas all algae and eubacteria examined have uninterrupted genes5–19. The distribution of these introns in Coleochaete, Nitella and Spirogyra, members of the Charophyceae, confirms that these taxa are part of the lineage that gave rise to land plants. Furthermore, the intron data place Coleochaete and Nitella closer to land plants than Spirogyra. These introns were most probably acquired by the chloroplast genome more than 400–500 million years ago, the time of land plant origin20.
Fluid mechanics in rectangular cavities — analytical model and numerics

Abstract We present an analytical model of Stokes creeping flows in rectangular cavities. In the model, the fluid normal velocity at the wall is zero, while the fluid tangential velocity at the wall differs from the wall velocity. Numerical work is used to validate some of the ideas generated from this realizable model.