cssi/SciSciGPT-SciSciNet huggingface dataset:
Hierarchical control of coherent gene clusters defines the molecular mechanisms of glioblastoma

Glioblastoma is a highly-aggressive and rapidly-lethal tumor characterized by resistance to therapy. Although data on multiple genes, proteins, and pathways are available, the key challenge is deciphering this information and identifying central molecular targets. Therapeutically targeting individual molecules is often unsuccessful due to the presence of compensatory and redundant pathways, and crosstalk. A systems biology approach that involves a hierarchical gene group networks analysis can delineate the coherent functions of different disease mediators. Here, we report an integrative networks-based analysis to identify a system of coherent gene modules in primary and secondary glioblastoma. Our study revealed a hierarchical transcriptional control of genes in these modules. We elucidated those modules responsible for conversion of the glioma-associated microglia/macrophages into glioma-supportive, immunosuppressive cells. Further, we identified clusters comprising mediators of angiogenesis, proliferation, and cell death for both primary and secondary glioblastomas. Data obtained for these clusters point to a possible role of transcription regulators that function as the gene modules mediators in glioblastoma pathogenesis. We elucidated a set of possible transcription regulators that can be targeted to affect the selected gene clusters at specific levels for glioblastoma. Our innovative approach to construct informative disease models may hold the key to successful management of complex diseases including glioblastoma and other cancers.
In Vivo Dissolution Measurement with Indium-111 Summation Peak Ratios

Dissolution of [111In]labeled tablets was measured in vivo in a totally noninvasive manner by using a modification of the perturbed angular correlation technique known as the summation peak ratio method. This method, which requires the incorporation of only 10–12 μCi into the dosage form, provided reliable dissolution data after oral administration of [111In]lactose tablets. These results were supported by in vitro experiments which demonstrated that the dissolution rate as measured by the summation peak ratio method was in close agreement with the dissolution rate of salicylic acid in a [111In]salicylic acid tablet. The method has the advantages of using only one detector, thereby avoiding the need for complex coincidence counting systems, requiring less radioactivity, and being potentially applicable to a gamma camera imaging system.
Orientation of the army ant neivamyrmex nigrescens: Integration of chemical and tactile information

Abstract The success of the large-scale raids and emigrations of the army ant Neivamyrmex nigrescens (Cresson) depends upon their ability to orientate by responding to a chemical trail and to tactile stimuli provided by physical objects. Laboratory experiments showed that the workers' response to tactile stimuli increases in the absence of a chemical trail. Under these conditions, test ants behave much as they do in the field at a raiding front. This may explain why raiding columns are typically established along the base of rocks, fallen tree trunks, and other inanimate objects. Other experiments show that tactile stimuli may, in turn, facilitate the ants' orientation to weak chemical trails.
Bromination at C-5 of pyrimidine and C-8 of purine nucleosides with 1,3-dibromo-5,5-dimethylhydantoin

Abstract Treatment of the protected and unprotected nucleosides with 1,3-dibromo-5,5-dimethylhydantoin in aprotic solvents such as CH 2 Cl 2 , CH 3 CN, or DMF effected smooth bromination of uridine and cytidine derivatives at C-5 of pyrimidine rings as well as adenosine and guanosine derivatives at C-8 of purine rings. Addition of Lewis acids such as trimethylsilyl trifluoromethanesulfonate enhanced the efficiency of bromination.
Adsorption of [(tBu)GaS]4 on GaAs(001)-(2×4)

Abstract We have conducted an ultrahigh vacuum investigation of [( t Bu)GaS] 4 adsorption on GaAs(001)-(2×4). Adsorbing [( t Bu)GaS] 4 at a surface temperature of 650 K results in a carbon-free overlayer as judged by Auger electron spectroscopy. For submonolayer coverages, scanning tunneling microscopy (STM) images show the presence of protrusions on the surface. The height distribution of these protrusions, which is insensitive to bias voltage, is peaked between 0.7 and 1.4 A, i.e., less than would be expected for the adsorption of intact Ga 4 S 4 cubane cores, suggesting that the Ga 4 S 4 cubane core of the [( t Bu)GaS] 4 molecular precursor has dissociated upon adsorption at 650 K. Further exposure to [( t Bu)GaS] 4 results in a nearly complete overlayer which contains small domains of a (2×1) GaS-induced reconstruction as judged by STM. Residing on the overlayer with (2×1) domains are features with heights between 3 and 4 A suggesting that the Ga 4 S 4 cubane core of the [( t Bu)GaS] 4 molecular precursor remains intact as adsorption at 650 K proceeds to the second layer of GaS. Upon annealing the overlayer to 790 K, STM images show adsorbates on a well-ordered (2×1) reconstructed surface. The height distribution of these adsorbates is peaked between 0.7 and 1.4 A, suggesting that annealing to temperatures above 700 K results in the dissociation of the second layer Ga 4 S 4 cubane cores that were adsorbed intact at 650 K. By annealing to 830 K, it is possible to desorb the second layer of GaS and obtain a (2×1) surface. Our STM images of this (2×1) reconstruction are consistent with a previously proposed model consisting of GaS heterodimers. Further adsorption of [( t Bu)GaS] 4 on the (2×1) surface at a temperature of 650 K results in clustering of the Ga 4 S 4 cubane cores into anisotropic GaS islands. The distribution of island aspect ratios ( d [110] / d [110] ) is peaked between 2 and 3.
The effect of dietary fiber on the bioavailability of digoxin in capsules.

Sixteen healthy volunteers were regularly given 0.4 mg of digoxin daily as two capsules with breakfast. After ten days during which breakfast was supplemented with 11 g of bran fiber, steady-state predose mean serum digoxin was lower (0.89 +/- 0.19 versus 0.84 +/- 0.18 ng/mL, P less than .05) and mean 24-hour area under curve determination was lower (30.5 +/- 6.1 versus 28.4 +/- 6.0 ng X hr/mL, P less than .05) than during the control period without bran. Height and time of peak serum digoxin, and 24-hour urinary digoxin were not significantly different. The 6 to 7% reduction in digoxin absorption from capsules is less than that reported from tablets and is probably clinically unimportant.
Improved Broadband Inversion Performance for NMR in Liquids

Abstract New NMR broadband inversion pulses that compensate both for resonance offset and radiofrequency (RF) inhomogeneity are described. The approach described is a straightforward computer optimization of an initial digitized waveform generated from either a constant-amplitude frequency sweep or from an existing composite inversion pulse. Problems with convergence to local minima are alleviated by the way the optimization is carried out. For a given duration and maximum allowable RF field strength B1 (but not necessarily given RMS power deposition), the resultant broadband inversion pulse (BIP) shows superior inversion compared to inversion pulses obtained from previous methods, including adiabatic inversion pulses. Any existing BIP can be systematically elaborated to build up longer inversion pulses that perform over larger and larger bandwidths. The resulting pulse need not be adiabatic throughout its duration or across the entire operational bandwidth.
TOXICITY AND SURVIVAL OUTCOMES OF HYPERFRACTIONATED SPLIT-COURSE REIRRADIATION AND DAILY CONCURRENT CHEMOTHERAPY IN LOCOREGIONALLY RECURRENT, PREVIOUSLY IRRADIATED HEAD AND NECK CANCERS

Background. Reirradiation of locoregionally recurrent, previously irradiated head/neck cancer may be considered in situations of unresectability, medical inoperability, or adverse pathologic features found at salvage resection. Methods. Retrospective cohort analysis of toxicity and survival outcomes in locoregionally recurrent, previously irradiated patients with head/neck cancer treated with hyperfractionated split-course radiotherapy and concurrent chemotherapy. Results. Between March 1998 and September 2006, 39 patients initiated reirradiation at median of 2.3 years (range, 0.5–19) following prior radiotherapy. At median survivor follow-up of 24.5 months (range, 3–63.9), 10 patients are alive without evidence of disease. Median survival is 19.0 months, with estimated 1-, 2-, and 3-year overall survivals of 60.1%, 45.1%, and 22.7%, respectively. Locoregional failure was the predominant site of postreirradiation recurrence. Male sex, total radiotherapy dose, cycles of chemotherapy completed, and clinical response were associated with improved overall survival. Conclusions. Reirradiation can offer long-term survival for patients with recurrent, previously irradiated head/neck cancers. © 2009 Wiley Periodicals, Inc. Head Neck, 2009
Trends in hospitalizations for adults with congenital heart disease in the U.S.

Objectives The purpose of this study was to better define the epidemiology of hospitalizations for adults with congenital heart disease (ACHD) in the U.S. Background There is a growing population of ACHD as the result of advances in pediatric care and diagnostic testing. Methods We used nationally representative data from the 1998 to 2005 Nationwide Inpatient Sample to identify patients ≥18 years of age admitted to an acute care hospital with an International Classification of Diseases-9th Revision code designating a CHD diagnosis. National estimates of hospitalizations and total hospital charges by year were calculated. Results The number of ACHD hospitalizations increased 101.9% from 35,992 ± 2,645 in 1998 to 72,656 ± 5,258 in 2005. During this period, the annual number of admissions grew for both simple (19,448 ± 1,614 to 44,707 ± 3,644) and complex (12,507 ± 1,172 to 19,973 ± 1,624) diagnoses. The percentage of admissions originating in the emergency department (41.7 ± 0.8%) or involving cardiac surgery (17.7 ± 0.7%) remained stable during the study period. The average patient age (52.3 ± 0.8 years to 53.8 ± 0.6 years, p Conclusions The number of hospital admissions for ACHD in the U.S. more than doubled between 1998 and 2005. Hospital charges attributable to these admissions have grown even more dramatically.
Control, exploitation and tolerance of intracellular noise

Noise has many roles in biological function, including generation of errors in DNA replication leading to mutation and evolution, noise-driven divergence of cell fates, noise-induced amplification of signals, and maintenance of the quantitative individuality of cells. Yet there is order to the behaviour and development of cells. They operate within strict parameters and in many cases this behaviour seems robust, implying that noise is largely filtered by the system. How can we explain the use, rejection and sensitivity to noise that is found in biological systems? An exploration of the sources and consequences of noise calls for the use of stochastic models.
Role of Phosphorylation in Progesterone Receptor Signaling and Specificity

Abstract Progesterone receptors (PR), in concert with peptide growth factor-initiated signaling pathways, initiate massive expansion of the epithelial cell compartment associated with the process of alveologenesis in the developing mammary gland. PR-dependent signaling events also contribute to inappropriate proliferation observed in breast cancer. Notably, PR-B isoform-specific cross talk with growth factor-driven pathways is required for the proliferative actions of progesterone. Indeed, PRs act as heavily phosphorylated transcription factor “sensors” for mitogenic protein kinases that are often elevated and/or constitutively activated in invasive breast cancers. In addition, phospho-PR-target genes frequently include the components of mitogenic signaling pathways, revealing a mechanism for feed-forward signaling that confers increased responsiveness of, PR + mammary epithelial cells to these same mitogenic stimuli. Understanding the mechanisms and isoform selectivity of PR/kinase interactions may yield further insight into targeting altered signaling networks in breast and other hormonally responsive cancers (i.e. lung, uterine and ovarian) in the clinic. This review focuses on PR phosphorylation by mitogenic protein kinases and mechanisms of PR-target gene selection that lead to increased cell proliferation.
Eosinophilic esophagitis—A mimic of GERD

Eosinophilic esophagitis (EE) is characterized by eosinophilic infiltration of the esophageal mucosa and results in clinical signs and symptoms that may be indistinguishable from those of gastroesophageal reflux disease (GERD). While demographic, clinical, and endoscopic features may be suggestive of EE, esophageal biopsy with tissue eosinophils averaging 24 per 400 x microscopic field remains the most specific diagnostic criterion. Previously rare, EE has been diagnosed in adults and children with increased frequency over the last decade; it appears to be a chronic disease and has a yearly incidence approximating 1:10,000 in the pediatric population. Dietary and respiratory antigen exposure with subsequent production of inflammatory chemokines is essential for development of EE in animal models of the disease. In humans, glucocorticoids and elimination of relevant dietary antigens have proved efficacious treatments for EE, resolving the disease at the mucosal level. Other therapies, including montelukast, partial dietary elimination, and bouginage have reduced symptoms without affecting mucosal inflammation. Evidence-based guidelines for the management of EE are not currently available. Current medical practice involving the management of reflux merits awareness and understanding of this emerging mimic. We present a review of the current understanding of this disorder.
Thermal degradation of xylan and related model compounds

Pyrolysis of O-acetyl-4-O-methylglucuronoxylan, 4-O-methylglucuronoxylan, and β-D-xylopyranosides involves thermal cleavage of the glycosidic groups. The resulting glycosyl units partly form random condensation products and are partly degraded to a variety of volatile products and char. Composition of the pyrolysis products changes with the introduction of additive or substituent groups. Addition of sodium hydroxide produces increased amounts of products of low molecular weight arising from carbonyl fragmentation and disproportionation, and zinc chloride promotes the formation of 2-furaldehyde, water, and char.
Refinements in mandible reconstruction

The basic approach to free flap mandible reconstruction is well established. Superior functional and aesthetic results are possible with appropriate preoperative planning and meticulous attention to detail during execution of the procedure. The most important factors under the surgeon's control that contribute to a high-quality result are accurate graft shaping and insetting, proper donor site selection, optimal incision planning, and a simplified approach to performing the microvascular anastomoses.
The Hydraulic Analogy for Electric Current

About 1900 the British scientist Sir Oliver Lodge (1851–1940) described a hydraulic analogue for electrical circuits that was widely used in the first half of the century and is still with us. Although some physics teachers object to the use of analogy in their presentations, the hydraulic analogue has become firmly fixed in our consciousness, and it is interesting to see how some older textbooks used it. The mechanical model of the emf is a bit strained, but the other models are easy to accept as analogues.
An outreach burn prevention program for home care patients

Residential fires are the major cause of death from fires and burns in the United States, accounting for nearly two-thirds of annual fatalities. High-risk groups are more accessible now to burn prevention programs because of increasing home health care. Our burn prevention program, directed at homebound patients cared for by our hospital-based home care staff, combines fire safety education and smoke detector installation for this designated high-risk population. The combining of home health care with burn prevention activities has proven to be an effective means of reaching thousands of high-risk homes per year. We believe this approach would be equally effective in other areas.
A reduced size antiresonant antenna for underground object detection

A reduced size antiresonant antenna for underground object detection is presented. The reduced size antenna is shown to provide improved differential impedance properties to that of a full size antiresonant dipole while providing a factor of eight reduction in the maximum dimension of the antenna.
Handwriter identification from one-bit quantized pressure patterns

Abstract The timing information contained in the on/off paper motions of handwriting is analyzed for its applicability to the problem of handwriter identification. Three different experiments on a data base of ten signatures from nine individuals are analyzed in terms of Type I and Type II error probabilities. Type I errors are found to be high (30–50%) while Type II errors are found to be low (4–12%). Analysis of the results suggests that one-bit pressure patterns are usable in a sequential handwriter recognition scheme for first stage screening of incoming signatures.
Predicting solute transport using mapping-unit data: model simulations versus observed data at four field sites.

Solute transport models may be used in conjunction with soils and climatic databases to predict the sensitivity of soil mapping units to leaching of agrichemicals. The primary objective of this study was to compare predicted solute transport obtained from several modeling approaches to observed data collected at four irrigated field sites throughout Montana. Observed solute distribution data as a function of soil depth was collected using Br and a moderately sorbing herbicide, bromacil (5-bromo-3-sec-butyl-6-methyluracil), for three sampling dates over a period of 1 yr and used for evaluating different approaches for generating model predictions. The observed data were compared to predictions generated by two process-based solute transport models, Chemical Movement in Layered Soils (CMLS) and Leaching Estimation and Chemistry Models (LEACHM), which differ in level of sophistication. Model predictions were obtained using inputs based on either detailed site characteristics (i.e., soil profile characterization) or the 1:24 000 scale USDA-NRCS Soil Survey (SSURGO) database coupled with parameter estimation routines. Comparisons of observed and simulated transport showed that although LEACHM and CMLS frequently underestimated solute transport, both models performed similarly using either site-specific inputs or SSURGO derived inputs. Model simulations using SSURGO soils data and 23 yr of historical climate data resulted in only slight variations in predictions of solute transport, suggesting that SSURGO inputs coupled with historic climate data provide a fairly robust approach for evaluating the sensitivity of mapping units to pesticide leaching out of the root zone.
NET TIME NEGOTIATIONS WITHIN THE FAMILY

Drawing on data from one-on-one and focus group interviews with high school students from schools in agricultural California, this research examines how American families negotiate what we call net time. The article explores intra-familial bargaining over time spent on the internet. Analysis pays special attention to families that prioritize capital-enhancing activities such as schoolwork and college applications. In these families, access to resources is guided by implicit social contracts between parents and children, as well as between siblings. The findings illuminate how these social contracts imply particular rights and responsibilities depending on the families' level of wiredness: highly wired, partially wired, and unwired families. Comparing the experiences of students from these three groups reveals that members of each kind of family experience a different form of net time. While youths from highly wired families enjoy individualized net time, members of partially wired families divvy up househ...
Cardiac hypertrophy: its characteristics as a growth process.

Abstract The causal relation between cardiac function and growth is analyzed in this review article. Three different levels of development are discussed: cytodifferentiation, embryogenesis and postnatal development. The earliest stage of cardiac morphogenesis, that is, the appearance of cellspecific proteins and of spontaneous contractions, appears to be independent of hemodynamic forces. Also, the first major morphologic transformation of the primitive heart, looping, is the intrinsic property of the heart itself. However, at any later stage of life, hemodynamic function in both health and disease is closely coupled to cardiac growth.
A landscape-based reconnaissance survey of estrogenic activity in streams of the upper Potomac, upper James, and Shenandoah Rivers, USA

Endocrine-disrupting compounds (EDCs) are becoming of increasing concern in waterways of the USA and worldwide. What remains poorly understood, however, is how prevalent these emerging contaminants are in the environment and what methods are best able to determine landscape sources of EDCs. We describe the development of a spatially structured sampling design and a reconnaissance survey of estrogenic activity along gradients of land use within sub-watersheds. We present this example as a useful approach for state and federal agencies with an interest in identifying locations potentially impacted by EDCs that warrant more intensive, focused research. Our study confirms the importance of agricultural activities on levels of a measured estrogenic equivalent (E2Eq) and also highlights the importance of other potential sources of E2Eq in areas where intensive agriculture is not the dominant land use. Through application of readily available geographic information system (GIS) data, coupled with spatial statistical analysis, we demonstrate the correlation of specific land use types to levels of estrogenic activity across a large area in a consistent and unbiased manner.
The Role of Nonspecific Factors in Cognitive‐Behavior Therapy for Depression

This article reviews the role of nonspecific treatment factors in cognitive-behavior therapy (CBT) for depression. An analysis of relevant studies reveals that the majority of symptomatic improvement in CBT occurs prior to the formal introduction of cognitive restructuring techniques. This suggests that other, likely nonspecific, treatment factors play a large role in mediating clinical improvement. Nonspecific factors are hypothesized to ameliorate patients’ feelings of hopelessness at the beginning of treatment, a process that catalyzes improvement across other depressive symptoms. Reviewed evidence supports a mediation role for the hopelessness construct in CBT. Two nonspecific factors, the treatment rationale and the assignment of homework, appear integral to early symptomatic improvement. The role of cognitive techniques is discussed in light of these findings.
GNEIMO-Fixman: An Accurate Torsional Molecular Dynamics Simulation Method for Studying Biomolecular Dynamics

Torsion angle Molecular Dynamics simulations provide a powerful alternative to all-atom MD since they place constraints on the bond lengths and angles, and thereby efficiently simulate large scale conformational changes in torsional space. The previous uses of torsional MD have been severely limited by the lack of efficient algorithms to solve the mathematical complexities of torsional MD. Our development of an advanced Generalized Newton-Euler Inverse Mass Operator (GNEIMO) torsional MD method overcomes these limitations with several theoretical and algorithmic advancements. We will outline these advancements and the effectiveness of the GNEIMO method in critical applications such as protein homology model refinement and protein conformational dynamics.Due to the rigidity in the model the torsional MD simulations show a bias in the partition function, which results in inaccuracies in the calculated thermodynamic and kinetic properties. Fixman developed a compensating potential that rigorously annuls the bias in the partition function, but the calculation of the Fixman potential has remained mathematically intractable even for moderate size molecules. Recently, we have developed a low-cost algorithm, based on Spatial Operator Algebra for calculating Fixman potential and torque for any molecule. We will present results on the validation and the effect of the Fixman correction potential in recovering the correct population distribution function, transition rates, and free energy surface for large branched systems.We have designed a modular software platform for the GNEIMO-Fixman method that can be readily combined with any type of forcefield engine. We have combined GNEIMO algorithm with Rosetta forcefield and performed homology model refinement with torsional MD. Thus our GNEIMO-Fixman torsional MD method allows for the use of larger integration time steps than for all-atom MD simulations, and enables enhanced conformational sampling in the low frequency torsional degrees of freedom.
Peripheral blood mononuclear cells of patients with breast cancer can be reprogrammed to enhance anti-HER-2/neu reactivity and overcome myeloid-derived suppressor cells

Two major barriers in the immunotherapy of breast cancer include tumor-induced immune suppression and the establishment of long-lasting immune responses against the tumor. Recently, we demonstrated in an animal model of breast carcinoma that expanding and reprogramming tumor-sensitized lymphocytes, ex vivo, yielded T memory (Tm) cells as well as activated CD25+ NKT cells and NK cells. The presence of activated CD25+ NKT and NK cells rendered reprogrammed T cells resistant to MDSC-mediated suppression, and adoptive cellular therapy (ACT) of reprogrammed lymphocytes protected the host from tumor development and relapse. Here, we performed a pilot study to determine the clinical applicability of our protocol using peripheral blood mononuclear cells (PBMCs) of breast cancer patients, ex vivo. We show that bryostatin 1 and ionomycin combined with IL-2, IL-7, and IL-15 can expand and reprogram tumor-sensitized PBMCs. Reprogrammed lymphocytes contained activated CD25+ NKT and NK cells as well as Tm cells and displayed enhanced reactivity against HER-2/neu in the presence of MDSCs. The presence of activated NKT cells was highly correlated with the rescue of anti-HER-2/neu immune responses from MDSC suppression. Ex vivo blockade experiments suggest that the NKG2D pathway may play an important role in overcoming MDSC suppression. Our results show the feasibility of reprogramming tumor-sensitized immune cells, ex vivo, and provide rationale for ACT of breast cancer patients.
First Report of Ustilago cynodontis Causing Smut of Cynodon dactylon in Washington State, United States.

Bermudagrass (Cynodon dactylon) is an important warm-season perennial turf and forage grass that is typically grown in warm, tropical and subtropical climates. Smutted inflorescences of bermudagrass were observed and collected in Benton County, Washington, United States, in October of 2012 in an unmanaged, naturalized area located near the banks of the Columbia River and adjacent to large expanses of managed turf containing bermudagrass. The climate in this area is favorable to bermudagrass due to the relatively mild winters and hot, dry summers that usually occur in this region. The infected plants occurred in patches alongside healthy plants and several disease foci were observed along a 100-m transect of non-contiguous bermudagrass. The disease was severe wherever it occurred. Diseased inflorescences were covered with black-brown teliospores, distorted, and frequently failed to fully emerge and develop. Teliospores (n = 80) were irregularly globose to subglobose, 5.3 to 7.0 × 4.5 to 6.2 μm (mean 6.4 × ...
Design of Advanced Titanium Structures

The emergence of new titanium fabrication techniques has opened up new possibilities for achieving high structural efficiency at considerably reduced costs. Superplastic forming/diffusion bonding (SPF/DB), combined with conventional metallurgical joining techniques, has been shown to effect weight reductions in future weapon systems. This paper shows how the basic steps utilized in structural design were altered in the application of SPF/DB to a Mach 2.0 aircraft.
Strain identification of highly-competitive bean rhizobia isolated from root nodules: Use of fluorescent antibodies, plasmid profiles and gene probes

Abstract Kim 5 and Viking 1 are highly-competitive N-fixing bean rhizobia ( Rhizobium leguminosarum biovar phaseoli ). Leonard jar studies were used to determine which of the two isolates was the most competitive. A mixed inoculant of both strains was added to bean seed ( Phaseolus vulgar is cultivar Tendergreen) in sterile sand. Single-strain inoculants were used for seed grown in soil containing indigenous rhizobia. Nodule occupancy was determined after harvest. Plasmid profiles of nodule isolates from bean seed inoculated with equal numbers of both strains showed that Kim 5 occupied 72% of the nodules. Plasmid profiles for Kim 5 revealed three distinctive bands as compared to two bands from Viking 1. One band appeared to be common to both strains, whereas Kim 5 had two unique bands. A 32 P-labelled gene probe to one of the unique Kim 5 plasmids was used to-detect Kim 5 isolated from nodules by colony hybridization. This technique showed that Kim 5 was found in 76.2% of the nodules. Fluorescent antibodies were also used to distinguish between isolates. When single-strain inoculants were used in non-sterile soil, fluorescent antibodies showed that Kim 5 was recovered in 67.5% of the nodule isolates compared to 17.6% for Viking 1, while the other isolates were indigenous rhizobia. These data demonstrate that Kim 5 is more competitive than Viking 1.
Human natural killer cells induce morphologic changes in porcine endothelial cell monolayers

In this study, we have investigated the early in vitro effects of natural killer (NK) cells on porcine aortic endothelial cell (PAEC) monolayers. Incubation of effector cells containing about 70% CD56+ cells on PAEC monolayers led to time-dependent changes in PAEC monolayer morphology. As little as 20 min of incubation resulted in changes in PAEC shape and in the appearance of gaps between the cells. These effects have been observed for up to 6 hr, but not before 20 min or after 6 hr. When NK-depleted effector cells were used, no morphological changes were observed in comparison with the same effectors before depletion; if CD56+ cells were added back, the effects were comparable with those on nondepleted effector cells. There was no detectable NK cell-mediated cytolytic activity during the 1-6 hr of incubation of peripheral blood lymphocytes with PAEC monolayers. These data indicate that NK cells may participate in endothelial cell changes leading to xenograft rejection.
Convection induced by selective absorption of radiation: A laboratory model of conditional instability

Abstract When there is internal heating in a fluid layer, convection can occur even if the static state is one of stable stratification. We have been investigating through laboratory experiments such a stably stratified layer of water which is heated above and cooled below. The water contains in dilute solution thymol blue (a pH indicator), which normally colors the water orange. It turns yellow if the pH is low, blue if the pH is high. A small DC voltage is applied across the layer, by using the bottom boundary as the positive electrode, the top boundary as the negative electrode. The hydroxyl ions formed near the bottom boundary cause the orange fluid to turn blue. The fluid layer is uniformly and steadily illuminated from above with light from a sodium vapor lamp. This radiation travels with negligible absorption through the orange fluid but is strongly absorbed by the blue fluid. The resultant warming of the blue fluid can lead to convective instability, with the blue fluid rising into warm upper layers, which it would continue to penetrate as long as it remains blue and as long as the radiative heating is sufficient to exceed the higher ambient temperatures above. This radiative heating occurs only in the blue rising flow; the sinking fluid is orange and is not heated. We have found that with a strongly stably stratified layer, convective plumes are unable to penetrate far and they remain shallow. However, for a weakly stratified layer, plumes grow tall and furthermore collect into a large convective cluster which persists as a steady coherent structure. The present paper deals also with the formulation of the governing equations to include the fluid-state-dependent heat source. A linear stability analysis shows that the critical Rayleigh number for onset of motion is drastically reduced. Furthermore, the cell size at onset is larger by a factor of √ 3 2 than in the classical Rayleigh-Benard convection problem. However, the laboratory fluid cells were much further broadened (by a factor of 8 or 10) when they penetrated into the stably stratified fluid above. In this case, the rising region is narrow and the sinking region is broad, so that downward vertical velocities are correspondingly small. In this way, the downwards-forced warm fluid has time to cool by conduction to the cold boundary. Steady finite amplitude solutions and their stability are analyzed and it is shown that there is a parameter range in which finite amplitude hexagonal cells are stable.
From cationic ring-opening polymerization to atom transfer radical polymerization

Roots of controlled radical polymerization, including atom transfer radical polymerization (ATRP), origi- nate in living ionic polymerizations accompanied by reversible deactivation, such as cationic ring-opening polymeri- zation of tetrahydrofuran and other heterocyclics. Recent developments in ATRP, including mechanistic understan- ding, synthesis of polymers with precisely controlled architecture and some applications of polymers prepared by ATRP are presented.
Determination of nucleic acid base ratios by gas-liquid chromatography.

Abstract A new method for the determination of base ratios of nucleic acids has been developed. This new method uses gas-liquid chromatographic analysis of the purines and pyrimidines arising on perchloric acid hydrolysis of the nucleic acids. The bases are separated as a single fraction from the other products of hydrolysis by a simple ion-exchange step and are analyzed as methylated derivatives which are formed, separated, and measured in the chromatographic unit on injection of the bases in alcoholic tetramethylammonium hydroxide. Useful data can be obtained on nanomolar levels of the bases. Refinement of the techniques should allow for extending the sensitivity of the method to the analysis of less than 1 microgram of nucleic acid.
Resource depletion, national income accounting, and the value of optimal dynamic programs

Abstract Under assumptions satisfied by many economic problems, I derive a fundamental new equation for the time rate of change of the optimal value function of any optimal control problem. This is then applied to Hotelling's model of the resource extracting firm. The precise differences between rent depreciation, and depletion charges are discovered, the flow and stock price appreciation rates are distinguished, and novel characterizations of mine value are derived. Most importantly, the correct contribution of mining to net national product (and to sustainable development) follows. In perfect foresight equilibrium, competitively managed mines can appreciate while being exhausted.
H+ desorption and hydrogen pairing on the hydrogenated Si(100) surface

Abstract We report the desorption of H + ions from hydrogenated Si(100) surface under the irradiation of 193 nm pulsed laser beam. The observed two groups of H + ions with mean kinetic energies of 0.09±0.05 and 0.38±0.06 eV are assumed to correspond, respectively, to the H + ions desorbing from doubly occupied and singly occupied dimers and the difference of 0.29±0.11 eV in their kinetic energies corresponds to the pairing energy on the H/Si(100) surface. The dependence of the H + yield on the laser fluence follows approximately a cubic law and the H + desorption cross-section is σ ≈10 −73 cm 6 s 2 . The experimental results are compared with the earlier studies of H + desorption as well as the more recent report of neutral H desorption from the H/Si(100) surface.
Why Do Faculty Members Leave a University

This paper uses the results of a survey of tenured faculty members who resigned from the University of Minnesota to analyze the factors that influenced their decisions to leave. The results indicate that the probability of accepting an outside offer is positively related to the expected salary gain, but that other general factors are also important determinants of faculty decision making in this area. However, even with the survey results, we know very little in any systematic sense about specific factors that influence individual faculty decisions, particularly about differences in these factors for those faculty who leave as opposed to those who remain. To analyze faculty retention more completely, we need additional information about the personal circumstances of faculty members who are and are not retention cases and more extensive information on why the retention cases made their eventual choices about staying at or leaving the institution.
Irradiation damage to pyrolytic graphites at very high temperatures

Six pyrolytic graphites of widely differing crystallite sizes (La == 1 to 120 mu m) were irradiated at temperatures of 1020 and 1475 deg C. The resulting damage was studied by transmission electron microscopy. Damage produced at 1020 deg C can be understood in terms of present nucleation ideas, assuming crystallite boundaries interfere with homogeneous nucleation when La is smaller than the separation of homogeneously nucleated defects. At the higher temperature there is an increase in defect density rather than a decrease as observed over the temperature range 150 to 1200 deg C. It is proposed that this is caused by the nucleating cluster being larger than in the lower temperature range, and hence having a larger migration activation energy, approximately 2 eV as opposed to 1.2 eV. (auth)
Eradication or decolonization of methicillin-resistant Staphylococcus aureus carriage: what are we doing and why are we doing it?

In the United States and, more recently, in parts of Canada, rates of health careassociated methicillin-resistant Staphylococcus aureus (MRSA) infection have continued to increase despite intensive infection-control efforts; in some series, 30% of isolates are methicillin resistant [ 13]. Some groups have advocated "search and destroy" policies that recommend routine screening for MRSA to identify, isolate, and treat carriers, with the ultimate goal of eradicating the pathogen from health care facilities [4]. The article by Simor et al. [5] in this issue of Clinical Infectious Diseases describes a randomized controlled study of an MRSA eradication strategy in health care facilities from a major metropolitan area in Canada. Evaluation of the efficacy of infectioncontrol strategies is difficult, particularly during outbreaks. Typically, several uncontrolled interventions are performed at once and analyzed in retrospect [6-8]. This study reflects the unique opportunity
Toward enhancement of the contribution of theory to environmental policy

Theory can be helpful to policy makers by pointing out surprising relationships unlikely to be recognized by unaided common sense; by noting significant exeptions to principles widely accepted; and by offering generalizations of its own. The paper argues that theorists may not have done enough of the first two and may have overstressed the last, giving insufficient warnings of pitfalls. Examples of each of the three are provided. The first is illustrated by a theorem which shows that any new energy source, such as gasohol, which is supplied only because of a subsidy, prospectively uses up more energy than it creates. The important exception application is illustrated by showing that subsidies which reward reduced emissions by the firm tend to increase pollution by the industry. Finally, the paper discusses inadvertent bias in the empirical evidence reasserting the superior performance of fiscal incentives for reduced environmental damage as compared to direct controls, thus casting doubt on the allegedly universal superiority of incentives.
Acute and Chronic Effects of Nonsteroidal Antiinflammatory Drugs on Glomerular Filtration Rate in Elderly Patients

To assess the effects of nonsteroidal antiinflammatory drugs (NSAIDs) on glomerular filtration rate (GFR) in elderly patients with and without renal insufficiency, we conducted an open-label, randomized, prospective three-period cross-over study. Twenty-nine patients at least 65 years old were assigned to groups with preserved GFR (> 1.16 mL/s [70 mL/min]) or with renal insufficiency (GFR 0.50-1.16 mL/s [30-70 mL/min]). Patients received 800 mg ibuprofen three times daily, 20 mg piroxicam daily, or 200 mg sulindac twice daily for 1 month. Three-hour inulin and two-day creatinine clearances were measured before and after the first and last doses of NSAIDs. Ibuprofen, piroxicam, and sulindac decreased inulin clearance after single-doses in both groups of patients. In patients with renal insufficiency, creatinine clearance did not change after administration of ibuprofen for 1 month (0 +/- 0.06 mL/s, mean +/- standard error), but was decreased similarly with administration of either piroxicam or sulindac (-0.12 +/- 0.06 mL/s [-7.2 +/- 3.6 mL/min], P < 0.02). One patient with preserved GFR, but with other risk factors for NSAID-associated renal impairment, met our criteria for withdrawal by experiencing at least a 40 mumol/L (0.5 mg/dL) increase in serum creatinine above their baseline value. Our data indicate that NSAIDs do not adversely affect GFR in patients with preserved renal function unless they have another risk factor for NSAID-associated renal impairment. In contrast, patients with renal insufficiency may have significant chronic decrements in GFR with long-acting NSAIDs such as piroxicam and sulindac, but not with short-acting ibuprofen. Such patients should have renal function monitored while being treated with long-acting NSAIDs.
The amyloidogenic pathway of amyloid precursor protein (APP) is independent of its cleavage by caspases.

Amyloid β-protein (Aβ) is the main constituent of senile plaques in Alzheimer's disease and is derived by proteolysis from the amyloid precursor protein (APP). Generation and secretion of both Aβ40 and Aβ42 isoforms depend largely on internalization of APP and occurs mainly in the endocytic pathway. Evidence has also been presented (Gervais, F. G., Xu, D., Robertson, G. S., Vaillancourt, J. P., Zhu, Y., Huang, J., LeBlanc, A., Smith, D., Rigby, M., Shearman, M. S., Clarke, E. E., Zheng, H., Van der Ploeg, L. H. T., Ruffolo, S. C., Thornberry, N. A., Xanthoudakis, S., Zamboni, R. J., Roy, S., and Nicholson, D. W. (1999) Cell, 97, 395–406) that caspase cleavage of APP at its cytosolic tail affects its processing such that it is redirected to a more amyloidogenic pathway, resulting in enhanced Aβ generation. However, caspase cleavage of APP also results in loss of its endocytosis signal (YENP), an event that would predict a decline in internalization and a concomitant decrease, not an increase, in Aβ generation. In the present work, we examined whether caspase cleavage of APP is relevant to amyloidogenesis. We found that 1) caspase cleavage of APP results in reduced internalization and, accordingly, a decline in Aβ secretion; 2) masking of the caspase site in APP did not affect Aβ levels and, 3) caspase activation in cells by serum withdrawal did not increase Aβ secretion. Thus, caspase cleavage of APP is unlikely to play a direct role in amyloidogenesis.
Decline of myoplasmic Ca2+, recovery of calcium release and sarcoplasmic Ca2+ pump properties in frog skeletal muscle.

1. The two calcium indicators Antipyrylazo III (AP III) and Fura-2 were used simultaneously to monitor free myoplasmic [Ca2+] in voltage-clamped cut segments of frog skeletal muscle fibres (8-10 degrees C). Antipyrylazo III was used for the relatively large [Ca2+] transients during 100-200 ms depolarizing pulses to -20 to 0 mV and for the rapid decline of [Ca2+] during the 200 ms after the pulses. Fura-2 was used to follow the slow decline of the small remaining elevation of [Ca2+] during the following 16 s (slow recovery period) and to monitor resting [Ca2+]. 2. From 1 to 16 s of the slow recovery period [Ca2+] declined with two exponential components, having time constants of 1.9 +/- 0.3 and 13.5 +/- 1.5 s (these and all other values are means +/- S.E.M. of eleven runs from seven fibres). At 1.2 s after the end of the pulses the amplitudes of the fast and slow exponential components of decline of [Ca2+] were 34 +/- 7 and 31 +/- 4 nM, respectively. The resting [Ca2+] in these runs was 40 +/- 4 nM. 3. The time course of calcium bound to parvalbumin [( Ca-Parv]) was calculated from the [Ca2+] records using literature values for the parvalbumin kinetic constants. From 1 to 16 s of the slow recovery period the total calcium [Ca]T outside the sarcoplasmic reticulum (SR) was assumed to equal [Ca-Parv] + [Ca-Fura]. During this period [Ca]T declined with two exponential components having time constants of 1.7 +/- 0.2 and 14.2 +/- 1.4 s, the same as those for [Ca2+]. Assuming the total concentration of parvalbumin cation binding sites to be 1000 microM, the fast and slow components of [Ca]T had amplitudes of 117 +/- 21 and 147 +/- 16 microM, respectively, at 1.2 s after the pulses. 4. The rate of decline of [Ca]T, -d[Ca]T/dt, was used as a measure of the net rate of removal of calcium from the myoplasm by the SR. From 3 to 16 s of the slow recovery period and in the resting fibre -d[Ca]T/dt varied with [Ca2+] according to A[Ca2+]n-L. The term A[Ca2+]n represents the pump rate and L represents a constant rate of calcium leak from the SR. 5. For 40 nM less than or equal to [Ca2+] less than or equal to 80 nM, the power n for the [Ca2+] dependence of pump rate was 3.9 +/- 0.6.(ABSTRACT TRUNCATED AT 400 WORDS)
Trypanosoma cruzi: choline acetyltransferase activity in tissues of susceptible and resistant mice infected with the Brazil strain.

Abstract In order to ascertain if there were biochemical differences in the autonomic nervous system of both C57BL/6-(resistant) and C3H/HeJ-(susceptible) mice infected with the “Brazil” strain of Trypanosoma cruzi we studied the depletion of the enzyme, choline acetyltransferase (EC 2.3.1.6) in the hearts and brains of these infected mice. In the hearts of C3H/HeJ mice, a 30–35% depletion of choline acetyltransferase was evident by day 7 of infection, a time characterized by lack of obvious parasitemia and frank morphological changes in the myocardium or atrial ganglia. When these mice were moribund (day 25) the depletion of choline acetyltransferase was approximately 40%. Myocardial inflammation, necrosis, and increased pseudocyst numbers were evident as the infection proceeded and as the parasitemia rose. In addition, right atrial ganglia were involved with inflammatory cells but were devoid of amastigotes. In resistant (B6) mice choline acetyltransferase levels were not depleted during the course of infection. Brain choline acetyltransferase levels were significantly depleted in moribund C3H mice but there were no frank morphological changes. Extracts of T. cruzi were devoid of any substances capable of inhibiting choline acetyltransferase. Choline acetyltransferase depletion in the hearts of infected susceptible animals precedes morphological alteration. Depletion of this enzyme may be utilized as an early parameter of infection.
Antioxidants and atherosclerosis

Several lines of evidence support a pro-atherogenic role for oxidized LDL. The most persuasive evidence, however, is that antioxidant feeding can retard the progression of atherosclerosis in animal models. This review focuses on the effect of antioxidants (probucol, a-tocopherol, ascorbate, (i-carot