cssi/SciSciGPT-SciSciNet huggingface dataset:
The Value of Angiography in the Diagnosis of Unruptured Aneurysms of the Abdominal Aorta

Abstract The advisability and value of angiographic studies in patients with abdominal aneurysm has been debated by many. Some believe that aortography is too dangerous for routine use and that diagnosis can always be established without it; further necessary information can be obtained safely at the time of operation [24]. Others [1, 6, 11] follow a middle-of-the-road policy and perform contrast-injection studies only if the clinical diagnosis is doubtful. Our experience based upon aortographic studies of 271 patients suspected of having unruptured aneurysm of the abdominal aorta is presented. The technique based on percutaneous catheter aortography proved to be safe, simple, and highly informative. Remote injections [3, 5, 10, 23, 24] were ruled out because they provided inadequate details. Two clinical signs, pulsating tumor and curvilinear calcification on conventional roentgenography, proved to be absolutely pathognomonic. A number of patients, however, had large abdominal aneurysms in the absence of both of these signs. Besides its value in diagnosing abdominal aneurysm, we also found that aortography supplied important additional information which in the average patient aided in effective preoperative planning. In the patient who was a doubtful candidate for operation, complete knowledge of pathological vascular anatomy permitted a more informed decision on whether to operate or not. We have never regretted the omission of aortography in our patients—Stipa and Shaw [24]
In situ Raman scattering in nanomaterial flame synthesis: a case on TiO2 nanoparticles (Retraction Notice)

This paper (SPIE Paper 66450V) has been retracted by the author and removed from the SPIE Digital Library on 20 October 2009. The original paper was published without the knowledge or consent of other collaborators, for which the author apologizes. As stated in the SPIE Guidelines for Professional Conduct and Publishing Ethics, "SPIE considers it the professional responsibility of all authors to ensure that the authorship of submitted papers properly reflects the contributions and consent of all authors." A serious violation of these Guidelines has occurred, necessitating that the paper be expunged from the conference proceedings.
A Revised Definition for Suppressor Variables: a Guide To Their Identification and Interpretation:

In the two-predictor situation it is shown that traditional and negative suppressors increase the predictive value of a standard predictor beyond that suggested by the predictor's zero order validi...
Static potential in string models

A class of string models is studied to leading order in a $\frac{1}{d}$ expansion, where $d$ is the dimensionality of space-time. The static potential is found to be given by $V(R)={M}^{2}R{(1\ensuremath{-}\frac{{{R}_{c}}^{2}}{{R}^{2}})}^{\frac{1}{2}}$, where ${R}_{c}$ is a critical distance. At $R={R}_{c}$, the system undergoes a phase transition to a state where a quasistatic string picture is no longer applicable.
TISSUE FACTOR PROCOAGUIANT CAPACITY OF NEONATAL LEUKOCYTES

Recent studies have demonstrated that leukocytes are an important source of a procoagulant which has been characterized as tissue factor (TF). Since DIC or intravascular thrombosis is often seen in newborn infants who have sepsis or severe hypoxia-acidosis, the procoagulant capacity of cord-derived leukocytes has been studied.
Gap junctional intercellular communication of bovine granulosa and thecal cells from antral follicles: effects of luteinizing hormone and follicle-stimulating hormone.

Throughout each estrous cycle, the gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), are involved in regulation of folliculogenesis. We have shown that LH or FSH affect cellular interactions mediated by gap junctions in bovine granulosa and thecal cells in vitro. To evaluate further the hypothesis that gonadotropins influence gap junctional intercellular communication (GJIC) and expression of gap junctional proteins known as connexins (Cx), throughout antral follicle development, granulosa and thecal cells from large (>10 mm; n=13), medium (5–10 mm; n=20), and small (<5 mm; n=27) follicles were cultured (n=4 cultures per size) with or without LH, FSH, or LH+FSH for 24 h. GJIC was evaluated (n=125–150 cells/treatment group) by using the fluorescent recovery after photobleaching technique and laser cytometry. Additionally, Cx43, Cx32, and Cx26 were detected in cultured cells by immunocytochemistry and Cx43 by Western immunoblot analysis. Finally, progesterone production by cultured cells was evaluated by radioimmunoassay. Across all follicles and treatments, GJIC was greater (p<0.01) for granulosa than thecal cells (4.9±0.05 vs 3.8±0.04%/min). For granulosa cells of large and medium follicles, LH and/or FSH did not affect GJIC. For granulosa cells of small follicles, FSH increased (p<0.05), but LH or LH+FSH had no effect on GJIC. For thecal cells of large follicles, LH increased (p<0.01) GJIC, whereas FSH or LH+FSH had no effects. For thecal cells of medium and small follicles, LH and/or FSH did not affect GJIC. These results demonstrate that FSH influenced GJIC of granulosa cells from small, but not from medium or large, follicles, and LH influenced GJIC of thecal cells from large, but not from medium or small, follicles. Cx43 was present as punctate staining between granulosa or thecal cells from all cultures, indicating assembled gap junctions. LH+FSH increased (p<0.05) expression of Cx43 only by thecal cells from large follicles. Cx32 was detected in the perinuclear cytoplasm of cultured granulosa or thecal cells, and in the cytoskeleton of a few cells per culture dish in all sizes of follicles. Cx26 was present in a regular pattern throughout the cytoplasm of granulosa or thecal cells in all sizes of follicles. For granulosa cells from large follicles, progesterone production was stimulated (p<0.05) with LH or FSH alone but was unaffected by LH+FSH. For granulosa cells from medium and small follicles, progesterone production was unaffected by LH and/or FSH. For thecal cells from all sizes of follicles, LH, FSH, and LH+FSH stimulated (p<0.05) production of progesterone. These data indicate that LH and FSH influence gap junction function and expression, which likely contributes to the development and maintenance of ovarian follicles.
First come, first served: grasses have a head start on forbs with prompt nutrient patch occupation

Graminoids and forbs are important entities in grassland community assembly, differing in their functional properties. In our study, we asked 1. Do graminoids and forbs differ in the speed of root proliferation into soil patches established under field conditions? 2. Is the patch occupation dynamics affected by the nutrient concentration in the patch? 3. What is the temporal dynamics of available macronutrients in an experimental patch and does it provide comparative advantage to any of these two categories in connection with their root proliferation dynamics? We used ingrowth core technique. Proliferated roots were sampled after 1, 2, 4, 8, or 15 weeks, with forb and graminoid categories distinguished on anatomical basis. We measured root length and root dry weight, concentration of NH4+, NO3−, and of exchangeable phosphorus in the soil. Roots of both functional groups proliferated more intensively in enriched soil patches than in the control ones, but graminoids entered experimental patches more rapidly. Soil concetration of available N fell down to the background level in four weeks. The initial head start by graminoids seems to be crucial for the overall patch exploitation, because the concentration of available nutrient forms, namely nitrate and ammonium, decreases rapidly.
Equilibrium shapes of Ni3Al crystallites formed during diffusion anneal

Observation de la formation de cristallites Ni 3 Al. Influence de la temperature de recuit sur la morphologie des cristallites
Emergent team coordination: from fire emergency response practice to a non-mimetic simulation game

We take the work practices of fire emergency responders as the basis for developing simulations to teach team coordination. We introduce non-mimetic simulation: economic operational environments that represent human-centered components of practice, such as team structures and information flows, without mimicking concrete aspects of an environment. Emergent team coordination phenomena validate the non-mimetic simulation of fire emergency response.We develop non-mimetic simulation principles through a game, focusing engagement on information distribution, roles, and the need for decisive real time action, while omitting concrete aspects. We describe the game design in detail, including rationale for design iterations. We take the non-mimetic simulation game design to participants for a series of play sessions, investigating how forms of information distribution affect game play. Participants coordinate as a team and, although they are not firefighters, begin to work together in ways that substantively reflect firefighting team coordination practice.
Optimization of Carrot Juice Color and Cloud Stability

Investigations were conducted on the effects of heating, acidification, and enzyme treatment on carrot juice color and cloud stability. Heating whole carrots to 93 o C prior to milling and pressing improved juice color, but reduced juice yield compared to heating milled carrots to 93 o C. Juice color was improved by acidification of milled carrots to pH 5 or 4 with citric acid prior to pressing. Juice from carrots heated before milling clarified quickly if not acidified before pressing. Acidification after juice extraction did not stabilize cloud. A commercial pectinase/hemicellulase preparation improved juice color, but not juice yield. Only 20% of potential β-carotene was extracted from carrots during pressing, and β-carotene was extracted to a greater extent than α-carotene
Selective mechanical stimulation of an identified proprioceptor in freely moving locusts: role of resistance reflexes in active posture

Direct mechanical stimulation of an identified proprioceptive sense organ, the femoral chordotonal organ of the locust hindleg, has been applied in freely moving animals to evaluate its function in maintenance of posture. A piezo-electric crystal mounted on the leg produced displacements of the main ligament of the organ mimicking 10-15 degree changes in joint angle. These stimuli produced consistent responses that (1) occurred as resistance reflexes to oppose the apparent joint movement and (2) demonstrated strong, tonic coupling of motoneuron activity to afferent input. These experiments have, therefore, directly demonstrated that the chordotonal organ functions in posture to aid in load compensation and to set the level of tonic motoneuron activity.
A partial answer to a conjecture of B. Simon concerning unique continuation

In his survey paper on Schrijdinger semigroups [S] B. Simon formulated the following Conjecture (see [S, p. 5193). Let VE KfP”, the local Kato class of potentials. Then the time-independent Schrddinger operator H= -d + V has the unique continuation property (ucp). By this it is meant that given any connected open subset 52 c R”, the only solution u of Hu = 0 in 52 that can vanish in an open subset 52, c Sz is u 0. A measurable function V on R” is said to belong to the Kato class K,, if
Improved dielectric properties of lead lanthanum zirconate titanate thin films on copper substrates

Thin films of lead lanthanum zirconate titanate (PLZT) were directly deposited on copper substrates by chemical solution deposition and crystallized at temperatures of {approx} 650 C under low oxygen partial pressure (pO{sub 2}) to create film-on-foil capacitor sheets. The dielectric properties of the capacitors formed have much improved dielectric properties compared to those reported previously. The key to the enhanced properties is a reduction in the time that the film is exposed to lower pO{sub 2} by employing a direct insertion strategy to crystallize the films together with the solution chemistry employed. Films exhibited well-saturated hysteresis loops with remanent polarization of {approx} 20 {micro}C/cm{sup 2}, dielectric constant of > 1100, and dielectric loss of < 0.07. Energy densities of {approx} 32 J/cm{sup 3} were obtained at a field of {approx} 1.9 MV/cm on a {approx} 1 {micro}m thick film with 250 {micro}m Pt electrodes.
A nuclear magnetic resonance study of toluene‐polyisobutylene solutions. 2. Vrentas‐Duda theory

The self-diffusion coefficients of toluene in polyisobutylene have been analyzed using the Vrentas-Duda free volume diffusion model. The diffusion coefficients were determined at different temperatures and concentrations, using the pulsed field gradient nuclear magnetic resonance technique. The data were satisfactorily described by the model and the size of the polymer jumping unit was extracted. Comparisons were made with the Fujita free volume theory and the Fujita free volume parameters were extracted from the Vrentas-Duda free volume parameters. From the diffusion data that now available, it can be concluded that for most polymers the jumping unit is about 1.5 times the polymer monomer molecular weight. The activation energy of the toluene diffusion in polyisobutylene is compared with the activation energies of other penetrants in the same polymer. The diffusion data presented in this work show that the energy per mole required to overcome the attractive forces which constrain a diffusing species to its neighbors should be considered to be zero, in order to be able to extract the free volume parameters (from viscosity and diffusion data) with an acceptable uncertainty. © 1995 John Wiley & Sons, Inc.
Gravitational waveforms for precessing, quasicircular binaries via multiple scale analysis and uniform asymptotics: The near spin alignment case

We calculate analytical gravitational waveforms in the time- and frequency-domain for precessing quasi-circular binaries with spins of arbitrary magnitude, but nearly aligned with the orbital angular momentum. We first derive an analytical solution to the precession equations by expanding in the misalignment angle and using multiple scale analysis to separate timescales. We then use uniform asymptotic expansions to analytically Fourier transform the time-domain waveform, thus extending the stationary-phase approximation, which fails when precession is present. The resulting frequency-domain waveform family has a high overlap with numerical waveforms obtained by direct integration of the post-Newtonian equations of motion and discrete Fourier transformations. Such a waveform family lays the foundations for the accurate inclusion of spin precession effects in analytical gravitational waveforms, and thus, it can aid in the detection and parameter estimation of gravitational wave signals from the inspiral phase of precessing binary systems.
Shadow Information Spaces: Combinatorial Filters for Tracking Targets

This paper introduces and solves a problem of maintaining the distribution of hidden targets that move outside the field of view while a sensor sweep is being performed, resulting in a generalization of the sensing aspect of visibility-based pursuit-evasion games. Our solution first applies information space concepts to significantly reduce the general complexity so that information is processed only when the shadow region (all points invisible to the sensors) changes combinatorially or targets pass in and out of the field of view. The cases of distinguishable, partially distinguishable, and completely indistinguishable targets are handled. Depending on whether the targets move nondeterministically or probabilistically, more specific classes of problems are formulated. For each case, efficient filtering algorithms are introduced, implemented, and demonstrated that provide critical information for tasks such as counting, herding, pursuit evasion, and situational awareness.
The Paramagnetic Correlation Length of Mn Thin Films

We have utilized Ginzberg-Landau mean field theory to analyze the branching ratio and soft X-ray magnetic circular dichroism measurements of the L3 and L2 adsorption edges of thin Mn overlayers on ferromagnetic fcc Co(001) at room temperature. We have determined a short range magnetic correlation of 4.25A and that the long range magnetic magnetic order has a decay length of 1.29A. These results indicate that the first monolayer of Mn ferromagnetically couple with the Co substrate. The paramagnetic Mn layer exhibits short range magnetic order, but lacks long range magnetic order. Due to the exponential decrease of both the branching ratio and dichroism signals, we have concluded that the magnetization of the Mn overlayer is substrate induced.
A regional atmospheric fate and transport model for atrazine. 2. Evaluation.

The Community Multiscale Air Quality (CMAQ) modeling system has been adapted to simulate the regional fate and transport of atrazine. Model modifications and simulations spanning April to mid-July 1995 are described in a previous paper. CMAQ results for atrazine concentrations in air and rainfall are evaluated against field observations taken along the Mississippi River and the shores of Lake Michigan in 1995. CMAQ results agree within 10% of published annual wet deposition load estimates for Lake Michigan and predicted annual dry deposition lies within published error bounds. Comparisons of weekly observed and predicted air and rainfall concentrations along the Mississippi River yield order-of-magnitude differences. Precipitation weighting of concentrations in rainfall good agreement for seasonal time frames. Weekly ambient gas form concentrations tend to be overpredicted by the CMAQ and semivolatile particulate fractions are underpredicted. Uncertainty in CMAQ predictions of air and rainfall concentrations for atrazine appear to derive primarily from uncertainty in emissions estimates, simulated precipitation, and spatial scale.
Metabolism of caffeine by mouse liver microsomes: GSH or cytosol causes a shift in products from 1, 3, 7-trimethylurate to a substituted diaminouracil

Abstract Incubation of [14C] caffeine with hepatic microsomes from male AKR/J mice resulted in the formation of several metabolites including 1, 3, 7-trimethylurate and 6-amino-5-(N-formylmethyl-amino)-1, 3-dimethyluracil. These two compounds comprised about 60% of products and are major urinary metabolites in several animals. When cytosol was included during incubation, there was a 14-fold increase in yield of the uracil at the expense of the urate; the combination of the two metabolites remained about 60% of total products. Cytosol alone was catalytically inert. Glutathione and other sulfhydryl compounds reproduced the effect of cytosol, and the action of cytosol was accounted for quantitatively by its sulfhydryl content. We propose that an oxidized intermediate of caffeine en route to trimethylurate is reduced by glutathione to the ring-opened uracil derivative.
Studies on oat gum [(1→3, 1→4)-β-D-glucan]: composition, molecular weight estimation and rheological properties

Abstract Oat gum was extracted from oat bran and examined chromatographically for monosaccharide constituent, presence of glycoprotein and equivalent dextran molecular weight (EDMW). Protein and ash contents were also determined. The viscosity of oat gum was studied at variable pH, temperature and concentrations of salt and sucrose. Viscosity of oat gum was compared with that of other food grade gums (xanthan, guar, gum arabic, and locust bean). TLC analysis identified only glucose and showed no evidence of xylose, arabinose or glycoprotein in the oat gum extract. The gum was 98.4% glucose as determined by high performance liquid chromatograpy. The protein and ash contents were 1.3% (N × 6.25) and 0.30%, respectively. EDMW of the extracted gum was ~882 000. Viscosity of oat gum (0.5%) was stable over a wide range of pH (2–10), decreased with increased temperature and increased in the presence of sucrose (20–45%). Oat gum was less viscous than xanthan and guar at 0.5%, but slightly more viscous than locust bean gum at the same concentration.
Recent Progress In Gradient-Index Optics

A brief summary of gradient-index (GRIN) optical principles is given, followed by a state-of-the-art review. Much of the important recent work has been in the area of GRIN materials, specifically: new glasses for ion exchange, new ion exchange techniques, GRIN sol-gel glasses and plastic GRIN. New metrology techniques and fabricated GRIN imaging systems are also discussed.
Absorption behavior of vanadium in Nafion

Abstract The absorption of vanadium to Nafion ® was investigated through ex-situ isotherm and conductivity measurements at 23 °C. The data show a maximum loss of ion exchange capacity (IEC) of 30% for all four oxidation states of vanadium. The affinity of vanadium for N115 was measured by back titration and atomic absorption (AA) and characterized by isotherms at 23 °C, and the affinity is highest for the divalent species and lowest for the pentavalent species in the following order: VO 2 + (V 5+ ) 2+ (V 4+ ) 3+ 2+ . Steric hindrance from the associated water complex may explain the lower absorption of vanadium compared to alkali metals. The conductivity for the VO 2+ (minimum affinity)-exchanged membrane was 2–3× lower than the sodium-exchanged membrane at an approximate RH = 100%.
Docosahexaenoic Acid Protects Muscle Cells from Palmitate-Induced Atrophy

Background. Accumulation of free fatty acids leads to lipid-toxicity-associated skeletal muscle atrophy. Palmitate treatment reduces myoblast and myotube growth and causes apoptosis in vitro. It is not known if omega-3 fatty acids will protect muscle cells against palmitate toxicity. Therefore, we examined the effects of docosahexaenoic acid (DHA) on skeletal muscle growth. Methods. Mouse myoblasts (C2C12) were differentiated to myotubes, and then treated with 0 or 0.5 mM palmitic acid or 0 or 0.1 mM DHA. Results. Intramyocellular lipid was increased in palmitate-treated cells but was prevented by DHA-palmitate cotreatment. Total AMPK increased in DHA
Adequacy and importance of lymph node evaluation for colon cancer in the elderly.

Background Studies have demonstrated improved survival when 12 or more nodes are examined for colon cancer. The elderly comprise a major proportion of patients with colon cancer, but it is unknown if examination of 12 or more nodes is appropriate for older patients. Our objective was to assess differences in lymph node evaluation by age and to determine whether adequate nodal evaluation (12 or more nodes) is associated with improved survival in the elderly. Study Design From the National Cancer Data Base (1998 to 2004), we identified 142,009 N0M0 patients who underwent colectomy for adenocarcinoma. Logistic regression was used to determine whether age is associated with adequate nodal examination. Multivariable modeling stratified by age was used to determine whether evaluation of 12 or more nodes is associated with improved survival. Results The median number of nodes examined was similar with increasing age (less than 67 years: 11 nodes; 67 to 78 years: 10 nodes; greater than 78 years: 10 nodes). Patients older than 78 years underwent evaluation of 12 or more nodes less frequently than patients less than 67 years old: 47.7% versus 41.4% (p Conclusions The elderly account for nearly half of patients with colon cancer. Older patients undergo inadequate lymph node evaluation more frequently than younger patients do. Improving lymph node evaluation will result in more accurate pathologic staging for the elderly.
Stromal protein degradation is incomplete in Arabidopsis thaliana autophagy mutants undergoing natural senescence

Degradation of highly abundant stromal proteins plays an important role in the nitrogen economy of the plant during senescence. Lines of evidence supporting proteolysis within the chloroplast and outside the chloroplast have been reported. Two extra-plastidic degradation pathways, chlorophagy and Rubisco Containing Bodies, rely on cytoplasmic autophagy. In this work, levels of three stromal proteins (Rubisco large subunit, chloroplast glutamine synthetase and Rubisco activase) and one thylakoid protein (the major light harvesting complex protein of photosystem II) were measured during natural senescence in WT and in two autophagy T-DNA insertion mutants (atg5 and atg7). Thylakoid-localized protein decreased similarly in all genotypes, but stromal protein degradation was incomplete in the two atg mutants. In addition, degradation of two stromal proteins was observed in chloroplasts isolated from mid-senescence leaves. These data suggest that autophagy does contribute to the complete proteolysis of stromal proteins, but does not play a major degenerative role. In addition, support for in organello degradation is provided.
NEONATAL LACTIC ACIDOSIS AND ACUTE RENAL FAILURE: THE ROLE OF PERITONEAL DIALYSIS

The treatment of hypoxic lactic acidosis with acute renal failure was studied in 2 neonates requiring peritoneal dialysis. In infant I pre-dialysis blood pH was 7.23, HCO3 13 mEq/L, and R fraction [(serum Na-(Cl− + HCO3)] 39 mEq/L representing accumulation of lactate, 35 mM/L. After 24 hours of peritoneal dialysis with a commercial solution containing 35 mEq/L sodium lactate, acidosis failed to improve and in fact worsened. HCO3 fell to 8 mEq/L while R rose to 47 mEq/L and plasma lactate to 40 mM/L. Increased acidosis was presumably due to loss of bicarbonate into dialysate. After dialysis with a solution containing 40 mEq/L of bicarbonate instead of lactate, acidosis was corrected with blood pH 7.45, serum HCO3 24 mEq/L, and R 22 mEq/L. In infant II predialysis blood pH was 7.18, serum HCO3 12 mEq/L, R 53 mEq/L, and plasma lactate 50 mM/L. Dialysate containing 40 mEq/L of sodium bicarbonate and no lactate was used. With concentration gradient favoring movement of HCO3 into and lactate out of extracellular fluid, serum HCO3 rose to 19 mEq/L and R fell to 39 mEq/L, blood pH 7.36. Improved circulation and oxygenation permitted metabolism of remaining lactate, producing a transient metabolic alkalosis. In acute renal failure with lactic acidosis, a peritoneal dialysate should be prepared containing sodium bicarbonate rather than lactate. Likewise acetate or other organic anions would not be metabolized effectively in hypoxic states.
“study” your way to better teaching

Faculty, like all other professionals, should be conscious of the need for continuing education in teaching as well as in mastery of their disciplines. This chapter lists some resources to help them keep up-to-date.
Is medical education research 'hard' or 'soft' research?

It is a common experience for those doing medical education research to be dismissed by our basic science and clinical colleagues as working in the ‘soft’ sciences, often with the implication that our research is ‘sloppy,’ else we would have the same rigor and precision of the ‘hard’ sciences. This perspective ignores, however, important differences in the contexts and constraints of doing ‘soft’ versus ‘hard’ research. Suppose we were to conduct research about the dispersion of an airborne infectious virus and the development of brain pathology as a result of exposure to that virus. A typical ‘hard’ science approach to this issue might look something like this. After a careful power analysis to determine the number of rats needed for the study, the researchers order several dozen rats from a laboratory animal supply firm. The firm would certify that all the rats are bred for genetic similarity and free from exposure to other pathogens. These rats would then be randomized into control and intervention cohorts. The intervention rats would be exposed to a controlled dose of the airborne virus for a specified period of time, whereas the control rats would be isolated from this virus. After exposure, all rats would be held in their cages for a pre-defined period of time to allow the virus to establish itself and develop any pathological consequences in the rat’s brain. During this incubation period, the intervention and control rats would be isolated from each other and kept in a controlled, sterile environment. After the incubation period, all the rats would be sacrificed and histological studies performed of the areas of the brain expected to show evidence of the viral pathology. If our researchers had to conduct this same study under the typical conditions for the ‘soft’ sciences, the process might look a bit different. First of all, the researchers would have to find their rats, which requires a hunting license from the local Society for the Prevention of Cruelty to Animals (SPCA) which stipulates that the researchers cannot simply capture their rats but must get their cooperation to participate voluntarily. The rat population is happily running around the sewers, abandoned buildings or fields and may or
Effect of physical activity on the absorption rates of procaine penicillin G implants

The pellet implantation technique was used to estimate quantitatively the effect of rat body movement on solid drug absorption rate. Animals placed in a rodent activity cage and rotated at 2.81 and 3.83 r.p.m. showed significantly greater mean absorption rates per mean area for procaine penicillin G pellets than nonrotated controls.
Myocardial Deformation in the Fetal Single Ventricle

Background In postnatal life, patients with single ventricle (SV) with morphologic right ventricles have a worse prognosis than those with morphologic left ventricles. The aim of this study was to test the hypotheses that (1) the SV in fetuses with SV has decreased longitudinal strain compared with fetuses with normal cardiac anatomy, and (2) fetuses with SV right ventricular (RV) morphology have decreased strain compared with those with SV left ventricular (LV) morphology. Methods Fetal echocardiograms with SV RV and SV LV morphology were retrospectively compiled. Postprocessing analysis of the dominant ventricle was done using syngo Velocity Vector Imaging version 2.0. Peak global longitudinal strain (GLS) and global longitudinal strain rate (GL SR) were generated. Both the right and left ventricles were analyzed in fetuses with normal cardiac anatomy for comparison. Results Fifty-four fetuses with SV (18 with LV morphology and 36 with RV morphology) were included in the study and compared with 54 controls matched for gestational age. Global longitudinal strain and GL SR were compared between fetuses with SV and normal fetuses and among SV subsets. When all four categories were compared (normal left ventricle, normal right ventricle, SV left ventricle, and SV right ventricle), there was no difference in GLS ( P = .49) or in GL SR ( P = .32) between any of the categories. Conclusions Comparable GLS and GL SR values between fetal SV of LV or RV morphology, as well as normal fetal left and right ventricles, reflect in utero preservation of systolic function of the SV heart.
Effect of surface acoustic waves on the catalytic decomposition of ethanol employing a comb transducer for ultrasonic generation

The effect of surface acoustic waves, generated on a silver catalyst using a comb transducer, on the catalytic decomposition of ethanol is examined. The comb transducer employs purely mechanical means for surface acoustic wave (SAW) transduction. Unlike interdigital SAW transducers on piezoelectric substrates, the complicating effects of heat generation due to electromechanical coupling, high electric fields between adjacent electrodes, and acoustoelectric currents are avoided. The ethanol decomposition reactions are carried out at 473 K. The rates of acetaldehyde and ethylene production are retarded when acoustic waves are applied. The rates recover to varying degrees when acoustic excitation ceases.
Comment on "Crustal contributions to arc magmatism in the Andes of Central Chile" by W. Hildreth and S. Moorbath

In their paper "Crustal contributions to arc magmatism in the Andes of Central Chile", Hildreth and Moorbath conclude that the stratovolcanos forming the volcanic front at the northern end, between 33-37.5 ~ S, of the Southern Volcanic Zone (SVZ, 33-46 ~ S) of the Andes, show along-arc changes in isotopic and elemental ratios that demonstrate a northward increase in crustal contributions to magma genesis. Stern et al. (1984a, b), Futa and Stern (1988) and Stern (1988) previously reached this same conclusion by comparing the chemistry of three of the northernmost volcanos in the SVZ, between 33-34 ~ S, with those from south of 36 ~ S. However, the processes by which crustal components are incorporated in Andean magmas, and specifically what is causing crustal components to be incorporated in increasing amounts in the magmas erupted at the northern end of the SVZ, remain controversial. With regard to Andean volcanism in general, Hildreth and Moorbath suggest that "although the principal magma source is presumed to lie within the mantle wedge fluxed by a slab-derived contribution" the '~ base-level isotopic and chemical values for each volcano are established by blending of subcrustal and deep-crustal magmas in zones of melting, assimilation, storage and homogenization (MASH) at the mantle-crust transition." They further suggest that the along-arc changes in isotopic and elemental ratios observed at the northern end of the SVZ are due to changing composition, age, and, most significantly, increased proportional contribution of the lowermost crust in conjunction with increased depth to the MASH zone as the crust thickens northward below the volcanic front. In contrast, Stern et al. (1984a), Futa and Stern (1988), and Stern (1988, 1991) argue that the distinctive petrochemical characteristics of the volcanoes at the northernmost end of the SVZ reflect a northward change in the composition and amount of continental components subducted into the mantle source region. Hildreth and Moorbath's preference for intra-crustal, upper-plate influence on the along-arc variations in magma chemistry at the northern end of the SVZ appears to be based on both geological and geochemical arguments that I find in many cases debatable. I discuss these separately below, followed by a brief comment on the relative effectiveness of lower crustal MASH versus mantle source region contamination processes in explaining along-arc chemical variations observed in Andean magmas.
Urea and Thiourea-Functionalized Mesoporous Silica Nanoparticle Catalysts with Enhanced Catalytic Activity for Diels–Alder Reaction

A series of urea- and thiourea-functionalized mesoporous silica nanoparticles (MSN) was synthesized. These materials exhibited a superior catalytic reactivity for Diels–Alder reaction than their homogeneous analogues. The reactivity enhancement was attributed to the site isolation effect induced by the heterogenization of individual catalytic group. The surface hydrogen bonding between the organic catalysts and silanols also improved the catalytic reactivity.
Colchicine overdose: report of two cases and review of the literature

Colchicine overdose is an uncommon but serious problem that may be missed or ignored unless the physician is aware of the significant potential for, and the various stages of, toxicity. We report two fatal cases in which the potential for lethal complications was not initially realized. Both patients developed multiple organ damage characteristic of severe colchicine toxicity. Awareness and appropriate initial therapy are important if death is to be prevented in colchicine overdose.
Application of a primitive variable Newton's method for the calculation of an axisymmetric laminar diffusion flame

In this paper we present a primitive variable Newton-based solution method with a block-line linear equation solver for the calculation of reacting flows. The present approach is compared with the stream function-vorticity Newton's method and the SIMPLER algorithm on the calculation of a system of fully elliptic equations governing an axisymmetric methane-air laminar diffusion flame. The chemical reaction is modeled by the flame sheet approximation. The numerical solution agrees well with experimental data in the major chemical species. The comparison of three sets of numerical results indicates that the stream function-vorticity solution using the approximate boundary conditions reported in the previous calculations predicts a longer flame length and a broader flame shape. With a new set of modified vorticity boundary conditions, we obtain agreement between the primitive variable and stream function-vorticity solutions. The primitive variable Newton's method converges much faster than the other two methods. Because of much less computer memory required for the block-line tridiagonal solver compared to a direct solver, the present approach makes it possible to calculate multidimensional flames with detailed reaction mechanisms. The SIMPLER algorithm shows a slow convergence rate compared to the other two methods in the present calculation.
Electrophoretic and immunological comparisons of chloroplast and prokaryotic ribosomal proteins reveal that certain families of large subunit proteins are evolutionarily conserved.

Antibodies to individual chloroplast ribosomal (r-)proteins ofChlamydomonas reinhardtii synthesized in either the chloroplast or the cytoplasm were used to examine the relatedness ofChlamydomonas r-proteins to r-proteins from the spinach (Spinacia oleracea) chloroplast,Escherichia coli, and the cyanobacteriumAnabaena 7120. In addition,35S-labeled chloroplast r-proteins from large and small subunits ofC. reinhardtii were coelectrophoresed on 2-D gels with unlabeled r-proteins from similar subunits of spinach chloroplasts,E. coli, andAnabaena to compare their size and net charge. Comigrating protein pairs were not always immunologically related, whereas immunologically related r-protein pairs often did not comigrate but differed only slightly in charge and molecular weight. In constrast, when35S-labeled chloroplast r-proteins from large and small subunits of a closely related speciesC. smithii were coelectrophoresed with unlabeledC. reinhardtii chloroplast r-proteins, only one pair of proteins from each subunit showed a net displacement in mobility.
Sunspot activity and the long-term variation of the Sun's open magnetic flux

[1] The interplanetary magnetic field (IMF) originates in open magnetic regions of the Sun (coronal holes), which in turn form mainly through the emergence and dispersal of active region fields. The radial IMF strength is proportional to the total open flux Φopen, which can be estimated from source surface extrapolations of the measured photospheric field, after correction for magnetograph saturation effects. We derive the long-term variation of Φopen during 1971–2000 and discuss its relation to sunspot activity. The average value of Φopen was ∼20–30% higher during 1976–1996 than during 1971–1976 and 1996–2000, with major peaks occurring in 1982 and 1991. Near sunspot minimum, most of the open flux resides in the large polar coronal holes, whereas at sunspot maximum it is rooted in relatively small, low-latitude holes located near active regions and characterized by strong footpoint fields; since the decrease in the total area occupied by holes is offset by the increase in their average field strengths, Φopen remains roughly constant between activity minimum and maximum, unlike the total photospheric flux Φtot. The long-term variation of Φopen approximately follows that of the Sun's total dipole strength, with a contribution from the magnetic quadrupole around sunspot maximum. Global fluctuations in sunspot activity lead to increases in the equatorial dipole strength and hence to enhancements in Φopen and the IMF strength lasting typically ∼1 year. We employ simulations to clarify the role of active region emergence and photospheric transport processes in the evolution of the open flux. Representing the initial field configuration by one or more bipolar magnetic regions (BMRs), we calculate its subsequent evolution under the influence of differential rotation, supergranular convection, and a poleward bulk flow. The initial value of Φopen is determined largely by the equatorial dipole strength, which in turn depends on the longitudinal phase relations between the BMRs. As the surface flow carries the BMR flux to higher latitudes, the equatorial dipole is annihilated on a timescale of ∼1 year by the combined effect of rotational shearing and turbulent diffusion. The remaining flux becomes concentrated around the poles, and Φopen approaches a limiting value that depends on the axisymmetric dipole strengths of the original BMRs. The polar coronal holes thus represent the long-lived, axisymmetric remnant of the active regions that emerged earlier in the cycle.
Agro-ecological drivers of rural out-migration to the Maya Biosphere Reserve, Guatemala

Migration necessarily precedes environmental change in the form of deforestation and soil degradation in tropical settlement frontiers. But what environmental factors may contribute to these migration streams in the first place? Identification of the environmental characteristics related to this process is crucial for understanding how environmental change and migration may form recurrent feedback loops. Further understanding of this process could be useful for developing policies to both reduce environmentally induced migration from origin areas and also palliate significant environmental change unleashed by settler deforestation in destination areas. Evidently, apprehension of this holistic process cannot be approached only from the destination since this ignores environmental and other antecedents to rural out-migration. This letter presents data from surveys conducted in areas of high out-migration to the agricultural frontier in northern Guatemala. The results suggest that land scarcity and degradation in origin communities are linked to out-migration in general and to the forest frontier of northern Guatemala in particular.
Mechanism of the stimulatory effect of 6-aminohexanoic acid on plasminogen activation by streptokinase or tissue plasminogen activator: the role of chloride.

Studies were conducted on the mechanism of the stimulatory effect of 6-aminohexanoic acid (6-AH) during thein vitro activation of human glutamic plasminogen (Glu-Plg) by streptokinase or by tissue plasminogen activator (t-PA) and the possible role of the addition of physiological concentrations of NaCl to the buffer solution. Enhancement by 6-AH was investigated by measuring the rate of plasmin generation using chromogenic substrate H-D-glu-phe-lys-pNA (S-2403). Control studies using plasmin showed that the addition of 6-AH at concentrations below 20 mM did not significantly affect the initial rate of the amidolytic activity of plasmin with or without the addition of NaCl to 0.05 M Tris buffer (pH 7.4). On the other hand, addition of NaCl to the buffer slowed down the initial rate of activation of Glu-Plg by streptokinase or by t-PA while increasing the percent enhancement by 6-AH when compared with the controls. The ratios of the initial rates of plasmin generation in the presence or in the absence of 6-AH were plotted against the inverse of the volume fraction of Glu-Plg, streptokinase or t-PA after serial dilutions. The results showed that when the activation reactions were performed in 50 mM of Tris buffer (pH 7.4), the enhancements by 6-AH were related to its interaction with streptokinase or t-PA, while using the same Tris buffer containing 0.6% NaCl, the enhancements by 6-AH were related to its interaction with both Glu-Plg and streptokinase or t-PA. However, upon increasing the NaCl to 0.9%, the results showed that the enhancements by 6-AH of the activation of Glu-Plg by streptokinase or t-PA were related to its interaction with Glu-Plg. The results suggested that changes in the concentrations of NaCl play a regulatory role during the activation process.
Ethanol's effects on auditory thresholds and reaction times during the acquisition of chronic ethanol self-administration in baboons

Abstract Baboons were trained to ingest ethanol at successively higher ethanol concentrations using oral self-administration techniques. Concurrently, animal psychophysical procedures were employed to determine auditory thresholds and reaction times daily. Maximal consumption of ethanol occurred at concentrations of 6–8% (w/v). During the initial period of ethanol self-administration, both auditory reaction times and auditory thresholds became elevated as animals consumed larger amounts of ethanol. For both the threshold and reaction time measures, the degree of elevation was correlated with the amount of ethanol consumed. These correlations decreased, however, with continued ethanol consumption. The elevations in sensory and motor function recovered to near-baseline levels when ethanol was no longer available.
THE SEDIMENTATION RATE OF THE BIOLOGICAL ACTIVITIES OF INFLUENZA A VIRUS.

The sedimentation rates of the mouse infectivity principles of the PR8 and the F12 strains of influenza A virus were shown by studies in the separation cell to have values which are not significantly different from sedimentation rates of the principal components of purified preparations. It was shown further that the bulk of the chicken red blood cell agglutinating activity and of the chick embryo infectivity of PR8 influenza virus preparations sediments at the same rate as that of the 100 mµ. component. Some activity was shown to be associated with aggregates. These results lend strong support to the assumption that the three biological activities are associated with the particles characterized as spheres with a diameter of about 100 mµ.
Concurrency control based on distributed cycle detection

This paper presents a novel optimistic concurrency control mechanism for distributed database systems. The optimistic concurrency control mechanism is based on a distributed algorithm for cycle detection which determines whether a transaction violates serializability or not. There are three advantages of this concurrency control mechanism. (1) It certifies execution of transactions in a distributed fashion and in parallel. (2) Local concurrency control is performed at each site independently. Global concurrency control verifies consistency of local concurrency control only when a transaction intends to commit. The separation of local and global concurrency controls enables us to integrate different local concurrency control mechanisms such as two-phase locking and timestamping into a single concurrency control mechanism. This is suitable for concurrency control in heterogeneous database systems. (3) No assumption is made on how data are distributed. It works in partially replicated database systems as well as in partitioned or fully replicated database systems.