cssi/SciSciGPT-SciSciNet huggingface dataset:
Can Siberian alder N-fixation offset N-loss after severe fire? Quantifying post-fire Siberian alder distribution, growth, and N-fixation in boreal Alaska

Fire severity affects both ecosystem N-loss and post-fire N-balance. Climate change is altering the fire regime of interior Alaska, although the effects on Siberian alder (Alnus viridis ssp. fruticosa) annual N-fixation input (kg N ha-1 yr-1) and ecosystem N-balance are largely unknown. We established 263 study plots across two burn scars within the Yukon-Tanana Uplands ecoregion of interior Alaska. Siberian alder N-input was quantified by post-fire age, fire severity, and stand type. We modeled the components of Siberian alder N-input using environmental variables and fire severity within and across burn scars and estimated post-fire N-balance using N-loss (volatilized N) and N-gain [biological N-fixation and atmospheric deposition]. Mean nodule-level N-fixation rate was 70% higher 11-years post-fire (12.88 ± 1.18 μmol N g-1 hr-1) than 40-years post-fire (7.58 ± 0.59 μmol N g-1 hr-1). Structural equation modeling indicated that fire severity had a negative effect on Siberian alder density, but a positive effect on live nodule biomass (g nodule m-2 plant-1). Post-fire Siberian alder N-input was highest in 11-year old moderately burned deciduous stands (11.53 ± 0.22 kg N ha-1 yr-1), and lowest in 11-year old stands that converted from black spruce to deciduous dominance after severe fire (0.06 ± 0.003 kg N ha-1 yr-1). Over a 138-year fire return interval, N-gains in converted black spruce stands are estimated to offset 15% of volatilized N, whereas N-gains in burned deciduous stands likely exceed volatilized N by an order of magnitude. High Siberian alder density and nodule biomass drives N-input in burned deciduous stands, while low N-fixer density (including Siberian alder) limits N-input in high severity black spruce stands not underlain by permafrost. A severe fire regime that converts black spruce stands to deciduous dominance without alder recruitment may induce progressive N-losses which alter boreal forest ecosystem patterns and processes.
Coronavirus disease 2019 (COVID-19) infection rates in a private school in Brooklyn, New York.

In March 2020, the World Health Organization (WHO) classified the coronavirus disease 2019 (COVID-19) outbreak as a pandemic; schools in the United States were ordered to close to minimize disease transmission1-2 . Serology-surveillance data are limited and there are no reports demonstrating the contribution of school closures to transmission control1-2 . School closure strategies might be national or local or based on student infection rates2 . In the current study, we sought to determine the COVID-19 infection rate in a private school in Brooklyn, New York during the re-opening school phase (Fall 2020).
Randomised trial of epinephrine dose and flush volume in term newborn lambs.

Objectives Neonatal resuscitation guidelines recommend 0.5–1 mL saline flush following 0.01–0.03 mg/kg of epinephrine via low umbilical venous catheter for persistent bradycardia despite effective positive pressure ventilation (PPV) and chest compressions (CC). We evaluated the effects of 1 mL vs 3 mL/kg flush volumes and 0.01 vs 0.03 mg/kg doses on return of spontaneous circulation (ROSC) and epinephrine pharmacokinetics in lambs with cardiac arrest. Design Forty term lambs in cardiac arrest were randomised to receive 0.01 or 0.03 mg/kg epinephrine followed by 1 mL or 3 mL/kg flush after effective PPV and CC. Epinephrine (with 1 mL flush) was repeated every 3 min until ROSC or until 20 min. Haemodynamics, blood gases and plasma epinephrine concentrations were monitored. Results Ten lambs had ROSC before epinephrine administration and 2 died during instrumentation. Among 28 lambs that received epinephrine, 2/6 in 0.01 mg/kg-1 mL flush, 3/6 in 0.01 mg/kg-3 mL/kg flush, 5/7 in 0.03 mg/kg-1 mL flush and 9/9 in 0.03 mg/kg-3 mL/kg flush achieved ROSC (p=0.02). ROSC was five times faster with 0.03 mg/kg epinephrine compared with 0.01 mg/kg (adjusted HR (95% CI) 5.08 (1.7 to 15.25)) and three times faster with 3 mL/kg flush compared with 1 mL flush (3.5 (1.27 to 9.71)). Plasma epinephrine concentrations were higher with 0.01 mg/kg-3 mL/kg flush (adjusted geometric mean ratio 6.0 (1.4 to 25.7)), 0.03 mg/kg-1 mL flush (11.3 (2.1 to 60.3)) and 0.03 mg/kg-3 mL/kg flush (11.0 (2.2 to 55.3)) compared with 0.01 mg/kg-1 mL flush. Conclusions 0.03 mg/kg epinephrine dose with 3 mL/kg flush volume is associated with the highest ROSC rate, increases peak plasma epinephrine concentrations and hastens time to ROSC. Clinical trials evaluating optimal epinephrine dose and flush volume are warranted.
Data-driven SFDI to measure molecular signals from widefield images

Machine learning offers a powerful set of tools to make widefield endoscopic imaging more quantitative. This presentation covers our work in estimating pixel size, topography, optical properties, and molecular chromophores using structured illumination and generative adversarial networks. We aim to create a computational endoscope that will improve computer-aided detection and diagnosis.
Circuit complexity near critical points

We consider the Bose-Hubbard model in two and three spatial dimensions and numerically compute the quantum circuit complexity of the ground state in the Mott insulator and superfluid phases using a mean field approximation with additional quadratic fluctuations. After mapping to a qubit system, the result is given by the complexity associated with a Bogoliubov transformation applied to the reference state taken to be the mean field ground state. In particular, the complexity has peaks at the $O(2)$ critical points where the system can be described by a relativistic quantum field theory. Given that we use a gaussian approximation, near criticality the numerical results agree with a free field theory calculation. To go beyond the gaussian approximation we use general scaling arguments that imply that, as we approach the critical point $t\rightarrow t_c$, there is a non-analytic behavior in the complexity $c_2(t)$ of the form $|c_2(t) - c_2(t_c)| \sim |t-t_c|^{\nu d}$, up to possible logarithmic corrections. Here $d$ is the number of spatial dimensions and $\nu$ is the usual critical exponent for the correlation length $\xi\sim|t-t_c|^{-\nu}$. As a check, for $d=2$ this agrees with the numerical computation if we use the gaussian critical exponent $\nu=\frac{1}{2}$. Finally, using AdS/CFT methods, we study higher dimensional examples and confirm this scaling argument with non-gaussian exponent $\nu$ for strongly interacting theories that have a gravity dual.
Brugada Syndrome: Fatal Consequences of a Must-Not-Miss Diagnosis.

Background Brugada syndrome is a genetic disorder of cardiac conduction that predisposes patients to spontaneous ventricular arrhythmia and sudden cardiac death. Although Brugada syndrome is one of the most common causes of sudden cardiac death, patients presenting with the syndrome often go misdiagnosed. This error has potentially fatal consequences for patients, who are at risk for sudden cardiac death without appropriate management. Objective To increase the critical care professional's knowledge of Brugada syndrome through detailed description of the characteristic electrocardiographic findings, an algorithmic approach to electrocardiogram evaluation, and a case report of a patient with a previously missed diagnosis of Brugada syndrome. The essential concepts of epidemiology, pathophysiology, clinical presentation, risk stratification, and management are reviewed for critical care professionals who may encounter patients with the syndrome. Diagnosis Patients typically present with syncope or cardiac arrest and an abnormal electrocardiographic finding of ST-segment elevation in the precordial leads. The diagnosis of Brugada syndrome centers on identification of its electrocardiographic characteristics by critical care professionals who routinely evaluate electrocardiograms. Critical care professionals, especially nurses and advanced practice nurses, should be proficient in recognizing the electrocardiographic appearance of Brugada syndrome and initiating appropriate management. Interventions Management strategies include prevention of sudden cardiac death through lifestyle modification and placement of an implantable cardioverter-defibrillator. Critical care professionals should be aware of commonly used medications that may exacerbate ventricular arrhythmia and place patients at risk for sudden cardiac death. Conclusion Increased awareness of Brugada syndrome among critical care professionals can decrease patient morbidity and mortality.
Synthesis of Radiating Systems with Flat Aperture According to a Prescribed Power Directivity Pattern. І. Finding the Set of Bifurcation Points of the Solutions

We study the problem of synthesis of a radiating system with flat aperture according to a prescribed power directivity pattern. We consider a special case where the field in the aperture is linearly polarized. It is shown that this class of problems is characterized by the nonuniqueness and bifurcation of solutions. The problem of finding the set of bifurcation points is reduced to the Cauchy problem for a differential equation of the first order. We construct numerical algorithms and present numerical examples of finding the bifurcation lines of solutions of the main equations of synthesis.
When Seamounts Subduct

Data from an array of seismometers on the sea floor show the complex pattern of earthquakes around subducted seamounts.
Sporadic Medulloblastomas Contain PTCH Mutations

Nevoid basal cell carcinoma syndrome (NBCCS), or Gorlin's syndrome, is an autosomal dominant disorder that predisposes to developmental defects and various forms of cancer. PTCH was recently proposed as a candidate gene for NBCCS due to its frequent mutation in basal cell carcinomas, the cancer most often associated with this syndrome. Another NBCCS-associated cancer is medulloblastoma, a common central nervous system tumor in children. Most medulloblastomas, however, occur without indication of an inherited predisposition. We have examined 24 sporadic medulloblastomas for loss of heterozygosity (LOH) at loci flanking as well as within PTCH. In cases with LOH, single-strand conformational polymorphism and sequencing analysis were performed to determine the status of the remaining PTCH allele. Microsatellite analysis indicated LOH of PTCH in 5 of 24 tumors, and in three of these cases a mutation of the remaining allele was identified. Two of the mutations were duplication insertions, and the third consisted of a single base deletion. It is interesting that all three mutations occur in exon 17 of the PTCH gene. These data suggest that inactivation of PTCH function is involved in the development of at least a subset of sporadic medulloblastomas.
The Hot Interstellar Medium of the Galactic Center: Observations with Chandra

Deep observations of the Galactic center with the ACIS instrument on the Chandra X-ray Observatory reveal a wealth of detail in the spatial distribution and the spectrum of the hot interstellar gas. Here we describe a few prominent characteristics of the diffuse emission from this region. The diffuse X-ray emission apparently occupying most of the volume within one parsec of the center appears to be partially density bounded on the outside by the dense circumnuclear disk located between 1 and ∼5 pc. Further out, on a scale of ∼10 pc, the diffuse emission is dominated by bipolar X-ray lobes which appear to be centered on the central black hole and oriented perpendicular to the Galactic plane. Within the bipolar lobes are several blobs of X-ray emitting gas which display a rough point reflection symmetry about the center and which are thus consistent with a succession of collimated ejections of hot gas from the immediate vicinity of the black hole. Nonthermal emission from a few places around the rim of the northern lobe of this structure indicates that highly relativistic particles are present in the otherwise apparently thermally emitting lobes.
CALCIUM SIGNALING BY CYCLIC ADP-RIBOSE AND NAADP : A DECADE OF EXPLORATION

Ca2+ mobilization as a signaling mechanism has been placed on center stage with the discovery of the first Ca2+ messenger, inositol trisphosphate (IP3). This article focuses on two new Ca2+ release activators, which mobilize internal Ca2+ stores via mechanisms totally independent of IP3. They are cyclic ADP-ribose (cADPR) and nicotinic acid dinucleotide phosphate (NAADP), metabolites derived respectively from NAD and NADP. Major advances in the past decade in the understanding of these two novel signaling mechanisms are chronologically summarized.
Abstract 1133: Partial EMT, hybrid epithelial-mesenchymal phenotype and epithelial plasticity: role of (miR-200/ZEB) loop

Epithelial to Mesenchymal Transition (EMT) and Mesenchymal to Epithelial Transition (MET) are critical for embryonic development and tissue repair. Aberrantly regulated transitions are also implicated in cancer metastasis. The core regulatory genetic network for these transitions appears to allow for the existence of a hybrid epithelial/mesenchymal phenotype (E/M). Such hybrid cells are seen during wound healing and branching morphogenesis, and have mixed epithelial and mesenchymal characteristics, which enable them to migrate collectively. The core regulatory network for the cell fate determination between these three phenotypes is composed of two highly interconnected mutual-inhibition feedback circuits - miR-34/SNAIL and miR-200/ZEB. Here we applied a novel theoretical framework to model the microRNA-based regulation to study this core regulatory unit. More specifically, we looked into the functions of the two loops in isolation, and subsequently of the combined unit when the two loops are integrated into the full regulatory circuit. We found that miR-200/ZEB forms a tristable circuit that acts as a ternary decision making switch, driven by miR-34/SNAIL that is a monostable loop which acts as noise-buffering integrator of internal and external signals that induce or inhibit EMT/MET. Our results are corroborated by recent experiments indicating the (miR-200/ZEB) to be the commitment point and decision making loop (eg. Cells don9t revert to epithelial phenotype on removal of EMT-inducing signal, if ZEB expression has been turned on.) .We associate the three stable states of the miR-200/ZEB circuit to different phenotypes - (1,0) - (high miR-200)/(low ZEB) - epithelial, (0,1) - (low miR-200)/(high ZEB) - mesenchymal, and (1/2,1/2) - (medium miR-200)/(medium ZEB) - hybrid. Thus, we propose that the hybrid epithelial - mesenchymal phenotype has concurrent expression of both miR-200 and ZEB. Our hypothesis is consistent with recent experimental studies (e.g. ZEB expression measurements in collectively migrating cells), and also explains the lack of hybrid phenotype observed during MET in colonization and induced pluripotent stem cells (iPSCs). We also present testable predictions of dynamic gene expression during complete and partial transitions (EMT/MET). Citation Format: Mohit Kumar Jolly, Mingyang Lu, Herbert Levine, Jose N. Onuchic, Eshel Ben-Jacob. Partial EMT, hybrid epithelial-mesenchymal phenotype and epithelial plasticity: role of (miR-200/ZEB) loop. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1133. doi:10.1158/1538-7445.AM2014-1133
Immunocytochemical expression and localization of protein kinase C in bovine aortic endothelial cells.

Abstract Total PKC activity in BAEC incubated for 24 hrs in either 10% serum (FBS) or serum-deprived media (SDM) was similar. However, most of the activity (69%) in the FBS group was detected in the particulate fraction, while it was mainly in the cystosolic fraction (66%) in the SDM group. By confocal microscopy, there was diffuse cytoplasmic localization of the antibodies to the α and β PKC isoforms. γ PKC was not detected. Treatment of FBS or SDM cells with a phorbol ester resulted in an increase in PKC activity with translocation to the particulate fraction. PKC α immunofluorescence redistributed to the perinuclear region whereas PKC β staining remained mostly cytosolic. Calphostin C, a PKC inhibitor, prevented the phorbol ester-induced increase in PKC activity and translocation.
Gas-Phase Clusters: Spanning the States of Matter

Gas-phase clusters, which are weakly bound aggregates comprised of either atoms or molecules, often display properties that lie between those of the gaseous and condensed states. Interesting questions arise concerning how large a cluster must be before it will display bulk properties. Currently there is extensive research activity directed toward studies of their formation and varying properties and reactivity as a function of the degree of aggregation. Results serve to elucidate at the molecular level the course of change of a system to be followed from the gas to the condensed state, thereby enabling a spanning of the states of matter.
Internal Invalidity in Studies Employing Self-Report Instruments: A Suggested Remedy.

It is axiomatic that, given a choice between a self-report and a behavioral measure of the same phenomenon, researchers will choose the behavioral measure. Likewise, when behavioral and self-report indices of the same construct show substantial discrepancies, it is seen as a signal to suspect the self-report measure rather than the behavioral measure (cf. Nisbett & Wilson, 1977). Hence, we have the time-honored practice of utilizing a behavioral measure as a criterion to determine the validity of a self-report instrument. In many areas of research, however, good behavioral measures are unavailable or extremely difficult to obtain (cf. Webb, Campbell, Schwartz, & Sechrest, 1966). Instructors are well aware, for example, of the difficulties encountered when trying to measure the attainment of affective objectives, and frequently the only way to determine whether such objectives have been met is by having students report their preferences or values before and after a particular course. Thus, it becomes important that researchers develop the best possible self-report measures, statistical procedures for analyzing self-report data, and research designs that effectively employ them. Howard, Ralph, Gulanick, Maxwell, Nance, and Gerber (in press) describe a potential confounding effect present in research designs which use self-report instruments. The potential confounding is caused by a phenomenon that the authors call a "responseshift." This paper describes the theory of response-shifts and the manner in which retrospective pretests may be used to deal with them. While Howard et al. examine the phenomenon in group training settings, the study described in the present paper is designed to demonstrate it in a classroom setting. Considerable attention has been devoted to the development of research designs which can be applied to a wide range of research problems (e.g., Campbell & Stanley, 1963; Cook & Campbell, 1976). Each design can be evaluated with respect to the degree to which it controls for the various sources of internal and external invalidity. True experimental designs (Campbell and Stanley's designs 4, 5, and 6) are commonly thought to control for all threats to internal validity (Campbell & Stanley, 1963). Two factors which might cause internal invalidity are history (specific events occurring between the first and second measurement in addition to the experimental variable) and instrumentation (changes in the calibration of a measuring instrument or changes in raters' standards). Use of a control group allows one to ascertain changes due to history with multiple "blind" raters and randomized rating material equalizing the effects of instrument decay for both the treatment and control groups. Thus, when history and instrumentation are considered singly their detrimental effects are controlled in true experimental designs. However, when self-report instruments are used, it is the research subjects themselves who serve as raters, and since treatment subjects have different
Convergence of emerging technologies to address the challenges of the 21 st century

There are numerous "Grand Challenges" facing humanity that will have to be addressed by us as a global society in order to maintain our well-being from the standpoint of quality of life, healthcare, environment, energy needs, manufacturing efficiencies, etc., if we are to continue humanity's trajectory of progress. Traditional technologies based on classical disciplines and thought processes of the past several decades are no longer viable in addressing these challenges, and a new approach based on interdisciplinary thinking is necessary. Fortunately, numerous emerging technologies are advancing at an unimaginable rate and it is the convergence of these technologies that demonstrate the potential to have a major impact on our lives, businesses, government, society and our planet. These emerging technologies are establishing the basis for a new paradigm in the development and commercialization of next generation intelligent, miniaturized, highly robust complex systems. This lecture will address some of these major technologies and their applications including, intelligent sensors and wireless sensor networks, intelligent cars and smart highways, tele-health (wireless healthcare), micro-electromechanical systems (MEMS), nanotechnology, clean technology, robotics and automation, smart grid, and ultra high throughput and wide bandwidth instrumentation.
Inducible repair of near-UV radiation lethal damage in E. coli.

We present here the initial characterization of a new repair system which is induced in actively growing cultures of Escherichia coli and which repairs a major fraction of lethal damage produced by near-UV (310–400 nm) light. This system is different from the error-prone ‘SOS’ repair system for DNA,known to be induced in E. coli by treatments which damage DNA and/or inhibit DNA replication, such as irradiation by far-UV (254 nm) light or X rays, thymine starvation or treatment with naladixic acid or mitomycin C1,2. The SOS response requires induction of an ‘X’ protein3, the product of the recA gene4–6, whereas the inducible repair system described here utilizes proteins distinct from the X protein.
Hydrodynamics in curved membranes: the effect of geometry on particulate mobility.

We determine the particulate transport properties of fluid membranes with nontrivial geometries that are surrounded by viscous Newtonian solvents. Previously, this problem in membrane hydrodynamics was discussed for the case of flat membranes by Saffman and Delbruck [P. G. Saffman and M. Delbruck, Proc. Natl. Acad. Sci. U.S.A. 72, 3111 (1975)]. We review and develop the formalism necessary to consider the hydrodynamics of membranes with arbitrary curvature and show that the effect of local geometry is twofold. First, local Gaussian curvature introduces in-plane viscous stresses even for situations in which the velocity field is coordinate-independent. Secondly, even in the absence of Gaussian curvature, the geometry of the membrane modifies the momentum transport between the bulk fluids and the membrane. We illustrate these effects by examining in detail the mobilities of particles bound to spherical and cylindrical membranes. These two examples provide experimentally testable predictions for particulate mobilities and membrane velocity fields on giant unilamellar vesicles and membrane tethers. Finally, we use the examples of spherical and cylindrical membranes to demonstrate how the global geometry and topology of the membrane influences the membrane velocities and the particle mobilities.
Analysis of a large nontranscribed spacer in the ribosomal DNA of the house cricket, Acheta domesticus (Orthoptera:Gryllidae).

An analysis of a 29-kilobase nontranscribed spacer fragment in the ribosomal DNA (rDNA) of the house cricket,Acheta domesticus, revealed a highly repetitious structure. A total of eightEcoRI repeats of three different size classes measuring 259, 420, and 508 base pairs (bp) was mapped to a region 2 kilobases (kb) from the 18 S coding region. The repeats were oriented in a nonrandom manner and had sequences homologous to DNA located immediately adjacent to the repetitive array. DNA sequence analysis showed that the reptitive region was composed of smaller direct repeats 66, 67, and 383 bp in length. There was minor length heterogeneity of the chromosomal restriction fragments containing the entire array, indicating that a variable number ofEcoRI repeats is a minor contributor to the total repeat-unit length heterogeneity. Immediately upstream from theEcoRI array there is a 17-kb region composed of 50 to 60 subrepeat elements recognized by a variety of restriction endonucleases. A subclonedSmaI repeat from the array was not homologous to any other part of the rDNA repeat unit or other chromosomal DNA. There was little length heterogeneity in restriction fragments containing the chromosomal 17-kb repetitions region. Immediately upstream from the 17-Kb region there is a 4.1-kb segment with sequences homologous to theEcoRI repeats.
Effects of Electroless Parameters on Fe Content in Ni-P-Fe2O3 Composite Coatings on Stainless Steel

Ferritic stainless steels have been widely used as solid oxide fuel cells (SOFCs) metallic interconnects. However, the evaporation of Cr2O3 might migrate to and poison the cathode, leading to degradation of the cell performance. In this work, Ni-P-Fe2O3 composite coating was deposited on the ferritic stainless steel by means of a cost-effective technique of electroless method. They are expected to be converted into (Ni,Fe)3O4 spinel with a high electrical conductivity and CTE match with stainless steel, which can hinder the evaporation of Cr2O3 formed on steel substrate exposed to the cathode environment of the SOFC. The effects of Fe2O3 contents, pH and temperature of solution on the deposition rate and Fe contents of the Ni-P- Fe2O3 composite coatings were investigated. The results indicated that the effects of Fe2O3 contents and pH of solution on deposition rate was not obvious and the deposition rate increased with increasing temperature. They had obvious influences on the Fe contents in the coating. The suitable deposition conditions are as below: the Fe2O3 content , pH and temperature was 16 g/L, 8.5 and 65 , respectively. The coatings consisted of Ni, Fe , P and O.
Quasi-One-Dimensional Modeling of Pulse Detonation Rocket Engines

Pulsed detonation rocket engines (PDREs) have generated considerable research interest in recent years as a chemical propulsion system potentially offering improved performance and reduced complexity compared to conventional rocket engines. The detonative mode of combustion employed by these devices offers a thermodynamic advantage over the constant-pressure deflagrative combustion mode used in conventional rocket engines and gas turbines. However, while this theoretical advantage has spurred a great deal of interest in building PDRE devices, the unsteady blowdown process intrinsic to the PDRE has made realistic estimates of the actual propulsive performance problematic. The recent review article by Kailasanath highlights some of the difficulties in comparing the available experimental measurements with numerical models. In a previous paper by the author, parametric studies of the performance of a single, straight-tube PDRE were reported. A 1-D, unsteady method of characteristics code, employing a constant-gamma assumption behind the detonation front, was developed for that study. Models of this type are computationally inexpensive, and are particularly useful for parametric performance comparisons. For example, a plot showing the specific impulse of various PDRE and steady-state rocket engine (SSRE) configurations as a function of blowdown pressure ratio. The performance curves clearly indicate that a straight-tube PDRE is superior in specific impulse to a SSRE with a sonic nozzle over the entire range of pressure ratios. Note, however, that a straight-tube PDRE in general does not compare favorably to a SSRE fitted with an optimized de Laval supersonic nozzle, particularly at the high pressure ratios typical for boost or in-space rocket applications. However, the calculations also show that if a dynamically optimized, supersonic de Laval nozzle could be could be fitted to a PDRE, then the specific impulse of the device would exceed that of a comparable SSRE. While such a nozzle is a considerable idealization, it is clear that nozzle design and optimization will play a critical role in whether the performance potential of PDREs can be effectively realized in practice. In order to study PDRE nozzle issues with greater accuracy, a quasi-one-dimensional, finite-rate chemistry CFD code has been developed by the author. Comparisons of the code with both the previous MOC model and experimental data from Stanford University are reported. The effect of constant-gamma and finite-rate chemistry assumptions on the flowfield and performance is examined. Parametric studies of the effect of nozzle throat size and expansion ratio, at various blowdown pressure ratios, are reported.
Bellechester, Minnesota, USA, lagoon collapses

Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×106 1 of partially treated effluent and about 600 m3 of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes.
RET signals through focal adhesion kinase in medullary thyroid cancer cells.

Background The RET proto-oncogene is implicated in medullary thyroid cancer (MTC) and has been shown to signal indirectly to focal adhesion kinase (FAK) in cell types other than MTC. We have previously shown that FAK is phosphorylated in MTC cells. We hypothesized that inhibition of RET with pharmacologic inhibitors or by depletion with siRNA would decrease FAK phosphorylation in MTC cells, thereby implicating a RET-FAK signaling pathway. Methods Human MTC cells (TT cells) were treated with pharmacologic inhibitors or transfected with RET siRNA. Total protein was detected by immunoblotting. Phosphorylated FAK was detected by immunoprecipitating total FAK and immunoblotting with antiphosphotyrosine. Results Treatment of MTC cells with the inhibitor PP2 significantly inhibited RET phosphorylation and, to a lesser extent, FAK phosphorylation. Imatinib mesylate inhibited FAK phosphorylation only at high doses. RET siRNA significantly decreased RET expression and FAK phosphorylation. Conclusions RET signals through FAK in MTC cells. Whether this is due to a direct or indirect interaction is not yet clear. PP2 or a similar inhibitor might be a useful treatment for MTC.
The role of the mitochondria in mediating cytotoxicity of anti-cancer therapies.

Optimal cytotoxic anticancer therapy, at the cellular level, requires effective and selective induction of cell death to achieve a net reduction of biomass of malignant tissues. Standard cytotoxic chemotherapeutics have been developed based on the observations that mitotically active cancer cells are more susceptible than quiescent normal cells to chromosomal, microtubular or metabolic poisons. More recent development of molecularly targeted drugs for cancer focuses on exploiting biological differentials between normal and transformed cells for selective eradication of cancers. The common thread of “standard” and “novel” cytotoxic drugs is their ability to activate the apoptosis-inducing machinery mediated by mitochondria, also known as the intrinsic death signaling cascade. The aim of this article is to provide an overview of the role of the mitochondria, an energy-generating organelle essential for life, in mediating death when properly activated by cytotoxic stresses.
Seizure activity and cortical spreading depression monitored by an extrinsic potential-sensitive molecular probe

Using surface fluorescence and reflectance measurements from the exposed cerebral cortex, several potential-sensitive molecular probes, primarily oxonol V, have been evaluated as indicators of electrical activity changes developing during seizure activity in the mongolian gerbil. Intraventricular injection of bicuculline, picrotoxin, or KCl produced characteristic cyclic molecular probe fluorescence intensity decreases that could be abolished by the uncoupler CCCP or the mitochondrial electron transport inhibitor rotenone. Smaller fluorophore signals were observed when KCl was applied topically to the exposed cortex. In some cases, as the animals were recovering from anoxia induced by nitrogen inhalation, oscillations similar to those due to spreading depression were observed in both the oxonol V and pyridine nucleotide signals. In all experiments, the molecular probe signals closely followed those of the intrinsic pyridine nucleotides. The drug-induced oxonol V signal alterations have been provisionally interpreted as due at least in part to the reduction of the mitochondrial membrane potential that accompanies a state 4 to state 3 transition. Measurements at the oxonol V fluorescence excitation wavelength indicated that only small changes in the reflectance signal occurred during seizure activity suggesting minimal blood volume change contributions to the extrinsic probe signal.
Swimming behavior as an indicator of sublethal toxicity in fish

Swimming behavior of fish is impaired by exposure to a diversity of contaminants. Gross aberrations in swimming can be qualitatively assessed while subtle changes in swimming behavior arising from sublethal exposures can be detected through a more detailed analysis of this response. Compared to other swimming behavior variables, the physical capacity to swim against water flow tends to be affected at relatively high toxicant concentrations and often presages mortality. Orientation to water flow, however, is altered at sublethal concentrations. Frequency of activity is a more sensitive measure in detecting contamination than measurements of survival alone. Alterations in swimming behavior have been detected during exposures to various contaminants at concentrations as low as 0.7 to 5% of their LC50 values and at concentrations that subsequently inhibited growth after longer periods of exposure. Analysis of swimming patterns provides even higher resolution for analysis of swimming behavior, and increased availability of the instrumentation necessary for such measurements should facilitate use of this approach. Fish swimming activity can easily be incorporated in test protocols to expand the sensitivity of standard toxicity tests.
Resolving power in a practical application of preparative sodium dodecyl sulfate polyacrylamide gel electrophoresis: preparation of Eastern encephalitis virus proteins.

Abstract Preparative polyacrylamide gel electrophoresis (PAGE) was used to separate the three proteins of Eastern equine encephalitis virus. The effect of gel length and gel concentration on the separation of these proteins was examined systematically. A single trial of preparative PAGE and the relative mobilities from analytical gel electrophoresis of a protein mixture provided the parameters needed to predict the elution times and resolution of the mixture components at other gel concentrations and gel lengths. The practical use of two simple formulas to determine the elution times and resolution of protein mixture components was demonstrated.
Spectral radiometric measurement of atmospheric constituents.

Atmospheric constituent vertical profiles have been determined from the height derivatives of their measured emission spectra. Samples of these spectra and derived profiles are shown. Several spectral radiometers have been employed to obtain these data from balloon and aircraft platforms. The radiometers are scanning grating monochromators operated at liquid nitrogen and liquid helium temperatures. The optical properties of these radiometers are discussed. Also the effect of these properties on radiometric accuracy is considered. Finally, a few methods for testing the accuracy of atmospheric data are developed.
The Relationship between Snow Accumulation at Mt. Logan, Yukon, Canada, and Climate Variability in the North Pacific

Abstract An ice core from Mt. Logan, Yukon, Canada, presents an opportunity to evaluate the degree to which ice core accumulation records can be interpreted as meaningful measures of interannual climate variability. Statistical analyses and comparisons with synoptic station data are used to identify the physical relationships between Mt. Logan ice core accumulation data and large-scale atmospheric circulation. These analyses demonstrate that only the winters of high accumulation years have a robust connection with atmospheric circulation. There are no consistent relationships during anomalously low and average accumulation years. The wintertime of high accumulation years is associated with an enhanced trough–ridge structure at 500 hPa and in sea level pressure over the northeast Pacific and western Canada, consistent with increased southerly flow bringing in warmer, moister air to the region. While both storm (i.e., 2–6 days) and blocking (i.e., 15–20 days) events project onto the same climate pattern, on...
Optical distortion in phase conjugation in high-gain three-wave mixing

Optical distortion of phase conjugates made in high-gain degenerate, optical parametric amplifiers (OPA) using three-wave mixing is discussed theoretically. The distortion is shown to be less severe than predicted by low-gain formulas. This result applied also to four-wave OPA’s in transmission configurations.
Novel chemical weapon of an exotic macroalga inhibits recruitment of native competitors in the invaded range

Summary 1. Allelopathy is an important non-resource interaction in terrestrial plant communities that may affect invasions by non-indigenous plants. The ‘novel weapons hypothesis’ (NWH) predicts that non-indigenous plants will become invasive if they have allelopathic compounds that assemblages in the new range are not adapted to. Recently, the non-indigenous, chemically rich macroalga Bonnemaisonia hamifera (Hariot) has become one of the most abundant filamentous red algae in Scandinavian waters. 2. We used B. hamifera to specifically test the aspect of the NWH that concerns invasion success based on novel allelochemicals in the invaded range. Allelopathic interactions were tested through effects on the growth rate of adult native macroalgae in co-cultures with B. hamifera and through the settlement success of native macroalgal propagules and microalgae on surfaces coated with 1,1,3,3-tetrabromo-2-heptanone. We also investigated whether 1,1,3,3-tetrabromo-2-heptanone can be transferred from B. hamifera to its native host algae, as a means of pre-emptive competition. 3. The settlement of native macroalgal propagules and microalgae was strongly inhibited on surfaces coated with 1,1,3,3-tetrabromo-2-heptanone at ecologically relevant concentrations, but there were no effects of adult B. hamifera on growth rates of adults of the six native naturally co-occurring species. The compound was shown to be transferred from B. hamifera to the surface of its native host algae at inhibitory concentrations in both laboratory and field experiments. 4. By inhibiting the settlement of propagules on its thallus and on surrounding surfaces, B. hamifera achieves a competitive advantage over native macroalgae, a finding that parallels previous reports on soil- and litter-mediated allelopathic interactions among vascular plants. Because competition for available substrata in marine benthic systems is intense, the ability to reserve space may be vital for B. hamifera’s successful invasion. This is the first example of an allelopathic compound that can be transferred by direct contact from an exotic to a native species, with an active and unaltered function. 5. Synthesis. Our results clearly show that the main secondary metabolite of the invasive red alga B. hamifera has strong allelopathic effects towards native competitors, suggesting that its novel chemical weapon is important for the highly successful invasion of new ranges.
Autoradiographic analysis of hormone-independent development of the mouse vaginal epithelium in organ culture.

Epithelial development was studied in organ cultures of vaginas from ovariectomized mice. In defined medium without estrogen, basal cell proliferation and formation of a stratified squamous epithelium occurred spontaneously in a high percentage of cases. During this “spontaneous” development, the length of the cell cycle and duration of DNA synthesis were the same as those occurring in vivo in response to estrogen. RNA synthesis was also stimulated. Thus, spontaneous development in vitro appears to resemble estrogen-induced development in vivo both qualitatively and quantitatively. In vitro, estrogen was found to have no detectable effect on the atrophic epithelium. In addition, estrogen was unable to halt degeneration of the fully developed epithelium on explants that had been estrogen-primed in vivo. The results suggest that both hormone-dependence and ability of hormones to induce a response are dependent on cell environmental factors.
Assessment of the early effects of 5,6-dimethylxanthenone-4-acetic acid using macromolecular contrast media-enhanced magnetic resonance imaging: ectopic versus orthotopic tumors.

Purpose To investigate the early effects of a vascular disrupting agent (VDA) in ectopic and orthotopic tumors by using macromolecular contrast media (MMCM)-enhanced magnetic resonance imaging (MMCM-MRI). Methods and Materials The MMCM-MRI of ectopic and orthotopic MCA205 murine fibrosarcomas was performed using the intravascular contrast agent albumin-(gadopentetate dimeglumine) 35 . Change in longitudinal relaxation rate (ΔR1) was measured 24 hours after treatment with 5,6-dimethylxanthenone-4-acetic acid (DMXAA; 30 mg/kg) and used to compute tumor vascular volume and permeability. Correlative histologic and immunohistochemical evaluation was carried out, along with measurement of tumor necrosis factor α and vascular endothelial growth factor levels in whole tumor extracts using the enzyme-linked immunosorbent assay. Results Orthotopic tumors showed higher vascular volume ( p p p Conclusions The MMCM-MRI provided early quantitative estimates of change in tumor perfusion after VDA treatment that showed good correlation with cytokine induction. Differences in the response of ectopic and orthotopic tumors highlight the influence of the host microenvironment in modulating the activity of VDAs.
Evaluating implicit spider fear associations using the Go/No-go Association Task.

Abstract The Go/No-go association task (GNAT) [Nosek, B.A., & Banaji, M.R. (2001). The Go/No-go Association Task. Social Cognition , 19 , 625–666], which measures automatic associations in memory, was administered to participants who were high ( N =17) versus low ( N =17) in spider fear along with other established fear measures to validate the tool as a proxy measure for fear schemata. The GNAT involves participants classifying stimuli into superordinate categories and looking at speed of categorization when categories match, versus contradict, participants’ hypothesized implicit fear associations. Results showed that the GNAT successfully differentiated the fear groups, indicating its convergent validity, and there was no group difference on a GNAT control fear task, supporting its discriminant validity. In addition, the GNAT spider fear task was associated with questionnaire measures of spider fear, self-reported anxiety during a behavioral avoidance test (approaching a live spider), and whether or not participants touched the spider during the behavioral test, supporting the task's predictive validity. Findings suggest the GNAT provides an effective, single-target measure of involuntary fear associations.
Capillary Displacement in Totally Wetting And Infinitely Long Right Prisms

We study capillary displacement in infinitely long right prisms filled with one wetting fluid and one nonwetting fluid, while restricting ourselves to zero gravity and totally wetting prism walls. At equilibrium, the intersection of the fluid-fluid interface with the cross section of the prism is composed of nonintersecting circular arcs with a uniform radius of curvature inversely proportional to the capillary pressure. We trace the circular arcs during capillary displacement using the so-called connected chordal axis (CCA) of the cross section. We identify the points on the CCA which are associated with the following events in the arcs’ “lives”: emergence, disappearance, end points (i.e., three phase contact points), getting pinned or unpinned, merging with another arc, or splitting into two arcs. The CCA comes with a decomposition of the cross section into triangular and trapezoidal regions marking the stages of the arcs’ lives. We also characterize the (polygonal) cross-sectional shapes for which the ...
A Method for Determining the Ash Content of the Leg Bones of Chicks With Slipped Tendon

Abstract STUDIES which have previously been reported indicate that the ash content of the leg bones of chicks afflicted with slipped tendon is not significantly different from that of the leg bones of apparently normal chicks of the same nutritional history. In most of these studies the bones of chicks afflicted with the disorder were taken at the end of the experimental period, and the chicks having slipped tendon were compared with normal chicks from the same lot. There are two disadvantages in this method. It is entirely possible that the chick which one chooses as normal might have developed slipped tendon within a short time and is, therefore, not really a normal chick. This difficulty can be somewhat obviated by choosing a sufficiently large sample. The practice of analyzing the bones of chicks with slipped tendon only after the chicks are eight or ten weeks of age is open to . . .