cssi/SciSciGPT-SciSciNet huggingface dataset:
Alternative FDTD Updating Schemes for Anisotropic Materials

A novel way of looking at the anisotropic finite difference time domain(FDTD) method is proposed based on the finite element point of view, which allows for a systematic approach of deriving anisotropic FDTD stencils without resorting to interpolation. A new stencil for anisotropic material media that properly accounts for material interfaces and perfect electric conductor boundaries is derived. This new stencil is tested and compared to analytical solutions and numerical solutions based on implicit finite element methods.
The relationship between association responses and activity in the pyramidal tract.

Abstract 1. 1. Correlation coefficients derived from comparison of the amplitude of association responses and the amplitude of the relayed pyramidal volley following auditory, visual and tactile stimuli were all highly significant. There was no correlation between primary auditory and visual responses and the pyramidal volley. Primary somatosensory responses evoked by contralateral tactile stimulation correlated with the pyramidal volley, but not as highly as with cortical responses elicited by ipsilateral stimuli. 2. 2. The responsiveness of the pericruciate cortex to a cortical stimulus was enhanced for 18–80 msec, then diminished for varying periods up to 500 msec following a peripheral stimulus in any of the three modalities. 3. 3. The results indicate that the association cortex of the pericruciate and other cortical association areas and efferent cortico-spinal fibers respond in a unitary fashion to a peripheral stimulus. The possible functional significance of these efferents is discussed.
RECCE mission planning

The ever increasing sophistication of reconnaissance sensors reinforces the importance of timely, accurate, and equally sophisticated mission planning capabilities. Precision targeting and zero-tolerance for collateral damage and civilian casualties, stress the need for accuracy and timeliness. Recent events have highlighted the need for improvement in current planning procedures and systems. Annotating printed maps takes time and does not allow flexibility for rapid changes required in today's conflicts. We must give aircrew the ability to accurately navigate their aircraft to an area of interest, correctly position the sensor to obtain the required sensor coverage, adapt missions as required, and ensure mission success. The growth in automated mission planning system capability and the expansion of those systems to include dedicated and integrated reconnaissance modules, helps to overcome current limitations. Mission planning systems, coupled with extensive integrated visualization capabilities, allow aircrew to not only plan accurately and quickly, but know precisely when they will locate the target and visualize what the sensor will see during its operation. This paper will provide a broad overview of the current capabilities and describe how automated mission planning and visualization systems can improve and enhance the reconnaissance planning process and contribute to mission success. Think about the ultimate objective of the reconnaissance mission as we consider areas that technology can offer improvement. As we briefly review the fundamentals, remember where and how TAC RECCE systems will be used. Try to put yourself in the mindset of those who are on the front lines, working long hours at increasingly demanding tasks, trying to become familiar with new operating areas and equipment, while striving to minimize risk and optimize mission success. Technical advancements that can reduce the TAC RECCE timeline, simplify operations and instill Warfighter confidence, ultimately improve the desired outcome.
Camphorylsulfonyl)imine dianion in the synthesis of new optically pure (camphorylsulfonyl)oxaziridine derivatives

Abstract New, more efficient enantiomerically pure (camphorylsulfonyl)oxaziridines are prepared by mono alkylation of the dianion of (camphorsulfonyl)imine at the carbon atom adjacent to the sulfonyl group.
Stochastic model of chemoattractant receptor dynamics in leukocyte chemosensory movement

Mammalian white blood cells are known to bias the direction of their movement along concentration gradients of specific chemical stimuli, a phenomenon called chemotaxis. Chemotaxis of leukocyte cells is central to the acute inflammatory response in living organisms and other critical physiological functions. On a molecular level, these cells sense the stimuli termed chemotactic factor (CF) through specific cell surface receptors that bind CF molecules. This triggers a complex signal transduction process involving intracellular biochemical pathways and biophysical events, eventually leading to the observable chemotactic response. Several investigators have shown theoretically that statistical fluctuations in receptor binding lead to "noisy" intracellular signals, which may explain the observed imperfect chemotactic response to a CF gradient. The most recent dynamic model (Tranquillo and Lauffenburger, J. Math. Biol. 25, 229-262. 1987) couples a scheme for intracellular signal transduction and cell motility response with fluctuations in receptor binding. However, this model employs several assumptions regarding receptor dynamics that are now known to be oversimplifications. We extend the earlier model by accounting for several known and speculated chemotactic receptor dynamics, namely, transient G-protein signaling, cytoskeletal association, and receptor internalization and recycling, including statistical fluctuations in the numbers of receptors among the various states. Published studies are used to estimate associated constants and ensure the predicted receptor distribution is accurate. Model analysis indicates that directional persistence in uniform CF concentrations is enhanced by increasing rate constants for receptor cytoskeletal inactivation, ternary complex dissociation, and binary complex dissociation, and by decreasing rate constants for receptor internalization and recycling. For most rate constants, we have detected an optimal range that maximizes orientation bias in CF gradients. We have also examined different desensitization and receptor recycling mechanisms that yield experimentally documented orientation behavior. These yield novel insights into the relationship between receptor dynamics and leukocyte chemosensory movement behavior.
Atypical Hemolytic Uremic Syndrome Post-Kidney Transplantation: Two Case Reports and Review of the Literature

Atypical hemolytic uremic syndrome (aHUS) is a rare disorder characterized by over-activation and dysregulation of the alternative complement pathway. Its estimated prevalence is 1-2 per million. The disease is characterized by thrombotic microangiopathy, which causes anemia, thrombocytopenia, and acute renal failure. aHUS has more severe course compared to typical (Infection-induced) HUS and is frequently characterized by relapses that leads to end stage renal disease (ESRD). For a long time, kidney transplantation for these patients was contraindicated because of high rate of recurrence and subsequent renal graft loss. The post-kidney transplantation recurrence rate largely depends on the pathogenetic mechanisms involved. However, over the past several years, advancements in the understanding and therapeutics of aHUS have allowed successful kidney transplantation in these patients. Eculizumab, which is a complement C5 antibody that inhibits complement factor 5a (C5a) and subsequent formation of the membrane attack complex, has been used in prevention and treatment of post-transplant aHUS recurrence. In this paper, we present two new cases of aHUS patients who underwent successful kidney transplantation in our center with the use of prophylactic and maintenance eculizumab therapy that have not been published before. The purpose of reporting these two cases is to emphasize the importance of using eculizumab as a prophylactic therapy to prevent aHUS recurrence post transplant in high-risk patients. We will also review the current understanding of the genetics of aHUS, the pathogenesis of its recurrence after kidney transplantation, and strategies for prevention and treatment of post-transplant aHUS recurrence.
Magnetic Fields of the Satellites of Jupiter and Saturn

This paper reviews the present state of knowledge about the magnetic fields and the plasma interactions associated with the major satellites of Jupiter and Saturn. As revealed by the data from a number of spacecraft in the two planetary systems, the magnetic properties of the Jovian and Saturnian satellites are extremely diverse. As the only case of a strongly magnetized moon, Ganymede possesses an intrinsic magnetic field that forms a mini-magnetosphere surrounding the moon. Moons that contain interior regions of high electrical conductivity, such as Europa and Callisto, generate induced magnetic fields through electromagnetic induction in response to time-varying external fields. Moons that are non-magnetized also can generate magnetic field perturbations through plasma interactions if they possess substantial neutral sources. Unmagnetized moons that lack significant sources of neutrals act as absorbing obstacles to the ambient plasma flow and appear to generate field perturbations mainly in their wake regions. Because the magnetic field in the vicinity of the moons contains contributions from the inevitable electromagnetic interactions between these satellites and the ubiquitous plasma that flows onto them, our knowledge of the magnetic fields intrinsic to these satellites relies heavily on our understanding of the plasma interactions with them.
A Multidimensional Assessment of Children in Conflictual Contexts: The Case of Kenya

Children in Kenya’s Kisumu District Primary Schools (N = 430) completed three measures of trauma. Respondents completed the My Worst Experience Scale (MWES; Hyman and Snook 2002) and its supplement, the School Alienation and Trauma Survey (SATS; Hyman and Snook 2002), sharing their worst experiences overall and specifically in schools. Participants also completed the Trauma and Attachment Belief Scale (TABS; Pearlman 2003), addressing their experiences of violence. The study examined children’s perceptions about themselves and others in the aftermath of violent experiences and the relationship between children’s trauma symptoms from experiencing violence and their social and academic functioning. Differences in the presence, frequency, and severity of symptoms emerged, with a large percentage attaining statistical and clinical significance. Research and practice implications are provided.
Improving disclosure of smoking by pregnant women.

Smoking is a major modifiable risk factor in pregnancy, and low-cost interventions have been developed and tested in diverse populations of pregnant smokers. Successful intervention depends on identification, however, and nondisclosure can be a problem. This randomized study compared rates of disclosure with two response formats-multiple choice, in which the patient is able to describe herself as having "cut down," and the usual history question, "Do you smoke?," in which she is forced to answer simply "yes" or "no." Each format was tested in both oral and written channels with a multiethnic adult prenatal population (n = 1078) entering care in a multispecialty group. Study results indicate that the multiple choice question improved disclosure, regardless of channel (oral versus written), by 40%. This effect was observed across racial and ethnic groups. Biochemical tests of urine samples from reported nonsmokers indicated smoking in only 3%. Eleven percent of the "nonsmokers" in the experimental groups refused consent for the urine test, however, and many of these were probably smokers.
Phase Relations in the Pseudobinary System Na2TiSi4O11‐Na2Ti2Si2O9

The quenching technique was used to study subliquidus and subsolidus phase relations in the pseudobinary system Na2 Ti2Si2 O11-Na2 Ti2 Si2 O9. Both narsarukite (Na2TiSi4O11) and lorenzenite (Na2Ti2Si2O9) melt incongruently. Narsarsukite melts at 911°±°C to SiO2+liquid, with the liquidus at 1016°C. Lorenzenite melts at 910°±5°C to Na2 Ti6 O13+liquid; Na2 Ti6 O13 reacts with liquid to form TiO2 and is thus consumed by 985°±5°C. The liquidus occurs at 1252°C.
Dependence of the adsorption of chiral compounds on their enantiomeric composition

Abstract The adsorption of two different chiral molecules on platinum surfaces has been explored as a function of enantiomeric composition. In the first case, the saturation monolayers obtained by the adsorption of 1-(naphthyl)ethylamine (NEA) from CCl 4 solutions were characterized in situ by reflection–absorption infrared spectroscopy (RAIRS). It was found that racemic mixtures yield different IR spectra than those obtained from enantiopure monolayers, a behavior that was interpreted as the result of the formation of racemate pairs via hydrogen bonding at the amine moiety also responsible for bonding to the surface. NEA adsorption under these conditions is reversible and can be modified by subsequent exposures to solutions of different chiral compositions, but that appears to take place only via changes in the relative fractions of enantiopure versus racemic domains on the surface; no other enantiomeric ratios are apparent in the IR data. The second study focused on the uptake of propylene oxide (PO) on Pt(111) under ultrahigh vacuum (UHV) conditions. In that case, racemic monolayers show densities up to ~ 20% lower than those obtained with one single enantiomer. This can be explained by kinetic arguments, since data from isothermal molecular-beam experiments indicated that the PO sticking coefficient depends on the chirality of the incoming PO molecules relative to that of the neighboring adsorbed PO species. Monte Carlo simulations could reproduce the experimental data by assuming adsorbate-assisted adsorption and enantiospecific adsorption geometries for molecules impinging on sites adjacent to previously adsorbed surface species.
Half-wave rectification and envelope detection utilising monolithic nanodiamond lateral field emission diode

Successful fabrication and characterisation of a vacuum microelectronic half-wave rectifier and envelope detector using a 2000-fingered nanodiamond lateral field emitter diode with 4 µm inter-electrode spacing is reported. The electrical characterisation demonstrates low turn-on field (∼1.4 V/µm) and high emission current, verified by the Flower-Nordheim plot. The diode is then connected in appropriate circuits to realise half-wave rectification and envelope detection. This approach demonstrates a new way of developing temperature- and radiation-tolerant integrated microelectronics.
THE APPARENT SHAPE OF THE STROMGREN SPHERE AROUND THE HIGHEST REDSHIFT QSOs WITH GUNN-PETERSON TROUGHS

Although the highest redshift QSOs (z > 6.1) are embedded in a significantly neutral background universe (mass-averaged neutral hydrogen fraction >1%) as suggested by the Gunn-Peterson absorption troughs in their spectra, the intergalactic medium in their vicinity is highly ionized. The highly ionized region is generally idealized as spherical and called the Stromgren sphere. In this paper, by combining the expected evolution of the Stromgren sphere with the rule that the speed of light is finite, we illustrate the apparent shape of the ionization fronts around the highest redshift QSOs and its evolution, which depends on the age, luminosity evolution, and environment of the QSO (e.g., the hydrogen reionization history). The apparent shape may systematically deviate from a spherical shape, unless the QSO age is significantly long compared to the hydrogen recombination process within the ionization front and the QSO luminosity evolution is significantly slow. Effects of anisotropy of QSO emission are also discussed. The apparent shape of the Stromgren sphere may be directly mapped by transmitted spectra of background sources behind or inside the ionized regions or by surveys of the hyperfine transition (21 cm) line emission of neutral hydrogen.
The migration kinetics of antiphase boundaries wetted by a second phase

Abstract Near the tricntical point in the Fe-Al system the disordered phase α perfectly wets the antiphase boundaries (APBs) of the ordered FeAl phase. This wetting phenomenon is used to assess the effects that the presence of a discrete interfacial layer of different composition from the bulk will have on interfacial migration. By keeping the volume fraction of a phase small, essential features of the topology of APBs are retained, but in addition a structure in many ways analogous to an adsorbed layer at the APBs is established. A velocity expression is derived for the APBs with the wetting layer by solving Fick's law for steady-state diffusion through a spherically shaped layer. Boundary conditions for the diffusion equation are determined from the Gibbs-Thompson effect. The velocity depends linearly on the driving force and hence on interfacial free energy, whereas the velocity expression developed by Alien and Cahn for APBs without adsorption does not. The velocity expression is used to develop a macroscopic theory of domain growth, and results in a linear relationship between the cube of the average domain size and time. Experimental measurements of antiphase domain coarsening kinetics in two Fe-Al alloys were made at temperatures where the wetting layer was present. The observed time and temperature dependence of domain coarsening process is compared to the theory. A linear relation between velocity and driving force for APBs with the wetting layer is consistent with the observations.
Fit and seal characteristics of a new paediatric tracheal tube with high volume-low pressure polyurethane cuff.

BACKGROUND To evaluate a new paediatric tracheal tube (Microcuff, Weinheim, Germany) with an ultrathin high volume-low pressure polyurethane cuff. METHODS With approval of the Hospital Ethics Committee tracheas of children undergoing general anaesthesia were intubated using a Microcuff tube. Tube sizes were selected according to: internal diameter (mm) = age/4 + 3.5 in children aged > or = 2 years. In newborns (> or = 3 kg) < or = 1 year, ID 3.0-mm tubes, and in children from 1 to 2 years, internal diameter 3.5-mm tubes were used. Tubes were classified too large if no air leakage was obtained at an airway pressure of 20 cm H2O with the cuff not inflated. Sealing pressure was assessed by auscultation. Post-extubation croup requiring therapy was noted. RESULTS Five-hundred children were studied. In eight children the tubes were too large. Sealing pressure was 9.7 +/- 2.5 cm H2O (4-20). In two patients postextubation croup required singular short-term therapy. CONCLUSIONS Microcuff paediatric tracheal tubes provided tracheal sealing with cuff pressures considerably lower than usually accepted. The rate of tube exchange was very low (1.6%), as was the rate of airway morbidity (croup requiring therapy; 0.4%).
A 45 nm Resilient Microprocessor Core for Dynamic Variation Tolerance

A 45 nm microprocessor core integrates resilient error-detection and recovery circuits to mitigate the clock frequency (FCLK) guardbands for dynamic parameter variations to improve throughput and energy efficiency. The core supports two distinct error-detection designs, allowing a direct comparison of the relative trade-offs. The first design embeds error-detection sequential (EDS) circuits in critical paths to detect late timing transitions. In addition to reducing the Fclk guardbands for dynamic variations, the embedded EDS design can exploit path-activation rates to operate the microprocessor faster than infrequently-activated critical paths. The second error-detection design offers a less-intrusive approach for dynamic timing-error detection by placing a tunable replica circuit (TRC) per pipeline stage to monitor worst-case delays. Although the TRCs require a delay guardband to ensure the TRC delay is always slower than critical-path delays, the TRC design captures most of the benefits from the embedded EDS design with less implementation overhead. Furthermore, while core min-delay constraints limit the potential benefits of the embedded EDS design, a salient advantage of the TRC design is the ability to detect a wider range of dynamic delay variation, as demonstrated through low supply voltage (VCC) measurements. Both error-detection designs interface with error-recovery techniques, enabling the detection and correction of timing errors from fast-changing variations such as high-frequency VCC droops. The microprocessor core also supports two separate error-recovery techniques to guarantee correct execution even if dynamic variations persist. The first technique requires clock control to replay errant instructions at 1/2FCLK. In comparison, the second technique is a new multiple-issue instruction replay design that corrects errant instructions with a lower performance penalty and without requiring clock control. Silicon measurements demonstrate that resilient circuits enable a 41% throughput gain at equal energy or a 22% energy reduction at equal throughput, as compared to a conventional design when executing a benchmark program with a 10% VCC droop. In addition, the microprocessor includes a new adaptive clock control circuit that interfaces with the resilient circuits and a phase-locked loop (PLL) to track recovery cycles and adapt to persistent errors by dynamically changing Fclk f°Γ maximum efficiency.
Recompaction of a coastal loamy sand after deep tillage as a function of subsequent cumulative rainfall

For many coastal plain soils in the southeastern USA, high soil strength within subsurface horizons requires that deep tillage be performed to provide a suitable rooting environment for row crops such as maize (Zea mays L.), wheat (Triticum aestivum L.), and soybean (Glycine max L. Merr.). We hypothesized that water filtering through the soil was recompacting it and that recompaction could be correlated with cumulative amount of rainfall since tillage. We measured cone indices in a structureless, fine loamy Acrisol near Florence, South Carolina, from 7 days to about 6 years after treatments were deep tilled. Measurements were made to a depth of 0.55 m at the point of maximum disruption of a bent-leg subsoiler (Paratill ® ) that tilled to a depth of 0.35–0.40 m. Regressions of cone indices with cumulative rainfall explained 67–91% of the recompaction and indicated that water filtering through the soil was causing the recompaction. Recompaction was slow, still taking place 6 years after tillage (the end of the experiment) probably because of controlled traffic or excessive disruption by the paratill. Recompaction was also temporarily greater for the 0.1–0.2 m depths when compared with that in the 0.25–0.35 m depths indicating that it was moving down the profile. Recompaction in other climates may be faster or slower depending on their cumulative rainfall relative to an annual amount of 900–1350 mm per year for this study and recompaction for structured soils may be faster or slower depending on whether the structure is stable or not. Though recompaction in this study was slow, tillage may still be necessary annually or seasonally because yield can be reduced even by incomplete recompaction that increases soil strength after a year or less. Published by Elsevier Science B.V.
IMPULSE ACTIVITY DIFFERENTIALLY REGULATES LEUENKEPHALIN AND CATECHOLAMINE |[lpar]|CA|[rpar]| CHARACTERS IN THE ADRENAL MEDULLA

Trans-synaptic impulse activity has long been known to increase CA biosynthesis and CA synthetic enzymes in the adrenal medulla. Since opiate peptides are co-stored and co-released with CA's in medullary cells, and since medullary opiate peptides may be important modulators of the sympathoadrenal stress response, we examined trans-synaptic regulation of the putative peptide neurohumour, leucine-enkephalin (ENK) and the CA enzymes, tyrosine hydroxylase (TH) and phenyl-ethanolamine-N-methyl transferase (PNMT) in the rat adrenal medulla in vivo and in vitro. Surgical denervation of the adrenal or pharmacologic blockade of synaptic transmission, treatments known to decrease CA traits, increased ENK-like immunoreactivity to 150% of control. Medullae explanted to culture exhibited a 50 fold rise in ENK in 4 days, whereas TH remained constant, and PNMT decreased to a new baseline. Depolarizing concentrations of K+ prevented the accumulation of ENK while not affecting TH or PNMT. Our studies suggest that enkephalinergic and catecholamine characters are differentially regulated by impulse activity and depolarization in the adrenal medulla. Independent regulation of adrenal neuropeptides and CA enzymes may allow new therapeutic approaches to shock, hypoxemia, or stress-induced analgesia through alteration of specific neurohumoral mechanisms. (Supported by NIH Grants HL00756, NS10259, and HD12108).
Stress analysis of particles in metals

Abstract A numerical solution is presented to the problem of an elastic spherical inclusion embedded in an elasticplastic infinite matrix subject to an axisymmetrical load. Various geometries and loads are considered for a wide range of materials. The analysis is concentrated on the stress distribution along the matrix-inclusion interface, and on the shape of the plastic zones in the matrix. This study has direct implications on ductile fracture, in particular on the initial stages of crack initiation and void nucleation.
Mathematical Representation of the Velocity, Temperature and Solid Fraction in an Electromagnetically Stirred Solidifying Melt

A mathematical model has been developed to describe the velocity, temperature and solid fraction in an electromagnetically stirred Al-5%Cu alloy in which 15% B4C particles were initially suspended. In the model, we allowed for the rheology of the melt-solid slurry and the release of latent heat either at the melt-solid interface, in the bulk or at an intermediate stage between those extremes. The calculations have shown that the evolution of the temperature and solid fraction profiles were not significantly affected, either by the stirring rate or by the choice of the location of release of latent heat.
Effects of caudate nuclei or frontal cortex ablations in cats. IV. Bar pressing, maze learning, and performance.

Abstract Bar pressing, maze learning, and passive avoidance acquisition were examined, before and/or after surgery, in cats with extensive unilateral or bilateral ablations of the caudate nuclei or frontal cortices and in sham-operated cats. The caudate ablations were by aspiration using a midline transcallosal approach. In a two-bar lever-pressing situation the acaudate animals showed specific defects consisting of difficulties in shaping the use of the paws, tendency to persist at the response producing the last reward, inability to execute two concurrent motor acts, and peculiar postural adjustments. These changes contributed to slow rates of responding, markedly impaired ability to alternate, and interfered with all phases of acquisition and performance. Frontal cats, conversely, exhibited markedly irregular behavior, inability to sustain performance, and slow rates of bar pressing without the other response peculiarities of acaudate cats. The unilaterally ablated animals exhibited only fragments of these defects. In a standard T-maze, on spatial alternation and black-white discrimination tasks, acaudate cats showed errors of perseveration while frontal cats produced mainly randomly distributed errors. Such defects were not seen in unilaterally lesioned animals. The above deficits did not manifest any marked recovery even in cats studied for up to 16 months. Passive avoidance was normal in all animals except the cat with the largest caudate removal. Sham-operated cats behave like intact animals. In conclusion: (i) Stable, chronic cats with caudate removal and absence of dorsofrontal cortical damage are capable of learning, retention, and performance far beyond previous suggestions; (ii) The discrete behavioral deficits resulting from extensive caudate or frontal lesions are different, suggesting that these structures play different functional roles. The deficits resulting from caudate destruction are discussed in terms of interference with high level sensory motor processess; their similarities with some clinical manifestations of human basal ganglia pathology are noted.
Review of Hyperimerus (Pteromalidae : Asaphinae) in North America, with Redescription of Hyperimerus corvus (Girault)

Abstract. The two North American species of Hyperimerus Girault are reviewed. Hyperimerus corvus Girault is redescribed from a newly designated lectotype, and the male is described for the first time. H. pusillus (Walker) is also redescribed briefly and new locality records provided to document range extension. Notes on extra-limital specimens of Hyperimerus from Guatemala, Japan, South Korea, Thailand are also provided.
Anthracyclines in the treatment of malignancy in pregnancy

This article reports two cases and reviews the literature regarding chemotherapy using anthracyclines during pregnancy. Twenty-six additional cases using this class of agents to treat malignancy during pregnancy are summarized from 18 reports for a total of 28 pregnancies. Final outcome of pregnancy is analyzed with regard to the following factors: diagnosis, gestational age at start of therapy, total dose of anthracycline, number and type of agents used, neonatal pathologic findings and months of follow-up of infants. Final outcome of 28 pregnancies resulted in 24 normal infants including a set of twins in the current report. Limited pharmacokinetic information is inconclusive with regard to the appearance of anthracyclines and their known metabolites in placental or fetal tissue.
Introduction to special section on Bridging Hydrology, Soil Science, and Ecology: Hydropedology and Ecohydrology

[1] This special section presents the results of interdisciplinary research related to two emerging and related disciplines that are focused on better understanding the interactions of soil, water and biological systems at the near-surface: hydropedology and ecohydrology. The results highlight the important linkages and feedback mechanisms between soil development, water movement, and the response of ecosystems at different spatio-temporal scales, through the use of field investigations and innovative methods of analyses. A deeper understanding of these linkages will inevitably improve our ability to address the complex environmental challenges of the 21st century.
The approximation of solutions to linear homogeneous differential equations by rational functions

Using methods analogous to those in diophantine approximation, the existence of good rational (function) approximations to the general solutions of each of a class of linear homogeneous differential equations is investigated. It is shown that, while many good approximations may exist, no truly extraordinary approximations exist. The proofs are via Lemmas on formal series which remain valid in a much wider context, e. g. even if the field of constants has positive characteristic.
Cellular Senescence in Telomerase-Expressing Syrian Hamster Embryo Cells

We have observed that normal, diploid Syrian hamster embryo cells (SHE) express the enzyme telomerase but undergo senescence at the end of their replicative lifespan. After 20-30 population doublings (pd) these cells cease proliferating, enlarge in size, exhibit a pH 6.0 senescence-associated beta-galactosidase activity, and fail to phosphorylate the RB protein or enter into S-phase after serum stimulation. We have observed that SHE cells express telomerase throughout their replicative lifespan and that the average telomere length does not appear to decrease, remaining at about 23 kb in senescent cells. In addition, individual clones of SHE cells also have telomerase activity and telomeres that do not decrease in length, ruling out the possibility that there is a rare, immortal subpopulation of telomerase-expressing cells that is lost during passaging. Together, these data suggest that SHE cells are likely to senesce by a mechanism that does not involve telomere loss.
Antigen-specific T-lymphocyte responses in acute and chronic syngeneic graft-versus-host disease

Abstract Administration of cyclosporine (CyA) following autologous bone marrow transplantation elicits a T-lymphocyte autoaggression syndrome with remarkable similarity to acute and chronic graft-versus-host disease (GVHD). This syndrome termed syngeneic (S) GVHD is mediated by a restricted repertoire of autoreactive T cells that promiscuously recognize major histocompatibility complex (MHC) class II determinants in association with a peptide from the invariant chain (CLIP). The present studies evaluated and compared antigen-specific autoreactive T cells during acute and chronic SGVHD isolated ex vivo with a soluble MHC class II-immunoglobulin (sMHC class II-Ig) molecular construct. Two major subsets were detected that had overlapping specificity recognizing the MHC class II binding domain of CLIP but were differentially dependent on the N- and C-terminal flanking domains of this peptide. Both subsets were detected in acute and chronic SGVHD. Interestingly, the cytokine profiles of the CLIP-reactive T cells closely correlated with the onset and progression of disease. Levels of type 1 cytokines, particularly IFN-γ mRNA production assessed by quantitative polymerase chain reaction (PCR), were dominant during acute SGVHD, whereas chronic SGVHD was associated with type 2 cytokine mRNA production. Although there was a dramatic polarization with respect to cytokine production, only subtle changes in antigen specificity were detected. Of additional interest, autoreactive T cells producing IL-10 mRNA were detected in both acute and chronic SGVHD, suggesting that this cytokine may play an important but perhaps paradoxical role in both the onset and progression of this experimental autoaggression syndrome.
PARP‐1 activation causes mitochondrial dysfunction

When activated by DNA damage, PARP1 consumes NAD+ to form ADP-ribose polymers on acceptor proteins. Excessive PARP1 activation during oxidative DNA damage is known to cause NAD+ depletion and cell death, but the intervening steps are not well understood. Sustained inhibition of the NAD+-dependent step in glycolysis is a potential consequence of NAD+ depletion. If this occurs, it should be possible to rescue cells from PARP1-mediated cell death by supplying alternative substrates for the mitochondrial tricarboxylic acid cycle. PARP1 was activated in cortical astrocyte and astrocyte-neuron cocultures with the DNA alkylating agent, N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). Studies using the 2-deoxyglucose method confirmed a sustained reduction in glycolytic flux, and studies with the JC-1 and TMRM indicate mitochondrial membrane depolarization. The addition of 1 mm of a-ketoglutarate or 1 mm pyruvate after washout of MNNG reduced cell death from 60 to 80% to near control levels, while addition of PARP inhibitors or excess glucose after MNNG washout had negligible effect. Cytoprotective effects remained significant with substrate delivery delayed up to 3 h after MNNG washout. The findings suggest that impaired glycolytic flux is a major factor in PARP1-mediated cell death, and suggest that supply of alternative mitochondrial substrates may be a promising strategy for delayed treatment of PARP1-mediated cell death in ischemia and other disorders.
Interactions in the flexible orientation system of a migratory bird

MIGRATING birds rely on interacting compass senses: magnetic, star, polarized light and perhaps Sun compasses1,2. During the development of orientation mechanisms, celestial rotation of stars at night3 and of polarized skylight patterns during the day time4 provide information about true compass directions that calibrates the direction of migration selected using the magnetic compass3–11. It might often be advantageous to adjust the magnetic preference by a geographic reference, especially at high northern latitudes where magnetic declination is large. Paradoxically, a magnetic preference so calibrated will be reliable only within a region of similar declination unless magnetic orientation remains open to calibration in older birds, something that earlier studies suggested was not the case1,2. We report here that in the Savannah sparrow (Passerculus sandwichensis) the same sort of calibration of magnetic orientation found in very young birds also occurs in older individuals exposed during the migration period to clear day and night skies within a shifted magnetic field.
A Warranted-assertability Defense of a Moorean Response to Skepticism

According to a Moorean response to skepticism, the standards for knowledge are invariantly comparatively low, and we can know across contexts all that we ordinarily take ourselves to know. It is incumbent upon the Moorean to defend his position by explaining how, in contexts in which S seems to lack knowledge, S can nevertheless have knowledge. The explanation proposed here relies on a warranted-assertability maneuver: Because we are warranted in asserting that S doesn’t know that p, it can seem that S does in fact lack that piece of knowledge. Moreover, this warranted-assertability maneuver is unique and better than similar maneuvers because it makes use of H. P. Grice’s general conversational rule of Quantity—“Do not make your contribution more informative than is required”—in explaining why we are warranted in asserting that S doesn’t know that p.
Increasing Response Rates to Long Questionnaires.

AbstractThe credibility of survey research is largely a function of response rate. It would be interesting to know how many studies have never reached the completion stage due to insufficient replies. This paper represents a synthesis of the literature and some personally devised techniques for gaining responses to long questionnaires, where the problems of high response rates are particularly critical. Although survey research techniques are an oft- neglected area of educational research, the questionnaire is probably the instrument most commonly used by doctoral students in completing their dissertations and by other educational researchers as supplemental data sources. Therefore how can we insure replies?
Minimizing Makespan with Bimodal Processing Time Distributions

We consider the problem of scheduling n tasks on two identical parallel processors. Task i has a processing time of one time unit, but might have to undergo processing for a second time unit with probability pi, i.e., the processing time distributions of the tasks have mass only on one and on two. We are interested in the sequence in which to process these tasks in order to minimize the expected completion time of all tasks. The optimal sequence turns out to be a sequence not well-known in the theory of scheduling.
Homeless children. Two years later.

In the May 1991 issue of the American Journal of Diseases of Children , I wrote of the health and social problems confronted by the nation's homeless children. 1 In September 1992, the federal government released its 1991 poverty report, the first of the annual reports to show the effects of the current recession. With the official 1991 federal poverty line for a family of four set at an annual income of $13 924, the number of Americans living in poverty in 1991 jumped by nearly 2 million over the 1990 figure, for an overall poverty rate of 14.2%. The total number of the poor, 35.7 million, represents a 27-year high. More households now receive food stamps than at any time in the program's history. Also, as has been true for many years, about 40% of the poor are children. Given the ferocity of the recession, all of these numbers will
Current Algebra From {Chern-Simons} Theories

Abstract We analyze odd-dimensional gauge field theories with action including both a Chern-Simons and a Yang-Mills term. When space-time has a spatial boundary the commutator algebra of Gauss law constraints acquires a boundary-valued anomaly which is related to anomalous chiral fermionic current algebra. We further study the limit in which the Yang-Mills term is removed and compute the corresponding anomalous boundary current algebras of pure Chern-Simons theories.
EFFECTIVELY RECOVERING OIL SPILLS TO GROUNDWATER

ABSTRACT Oil spills which do not reach surface waters are often given little consideration. These spills are frequently the most difficult to clean up and pose a threat to human health and well-being by virtue of contamination of potable water supplies and release of explosive vapors in houses or commercial establishments. The cleanup is nearly always more time consuming and expensive. Three methods have been used successfully for recovering hydrocarbons from groundwater. Recovery wells. The area of contamination must first be established by use of observation wells. The recovery wells consist of 12-to-16 in wells pumped to waste to create a cone of depression and cause the hydrocarbons to accumulate in that cone. A skimmer pump located either within the drawdown well or directly adjacent to it pumps the product to storage. Recovery trench method. In areas of high groundwater (less than 10 ft to water), a recovery trench may be used to recover product from groundwater. This method employs a trench dug int...
Reduction of the metallochromic indicators arsenazo III and antipyrylazo III to their free radical metabolites by cytoplasmic enzymes.

At a concentration much lower than that usually employed for measuring cytosolic ionized Ca2+ concentrations, arsenazo III underwent a one-electron reduction by rat liver cytosolic fraction or a hypoxanthinexanthine oxidase system to produce an azo anion radical metabolite. NADH, NADPH, N1-methylnicotinamide, hypoxanthine, and xanthine, in that order, could serve as a source of reducing equivalents for the production of this free radical by the cytosolic fraction. The steady-state concentration of the azo anion radical and the arsenazo III-stimulated O2 consumption were enhanced by calcium and magnesium. Antipyrylazo III was ineffective in increasing O2 consumption by rat liver cytosolic fraction and gave a much weaker ESR signal of an azo anion radical with both the liver cytosolic fraction, in the presence of NADH, and the hypoxanthine-xanthine oxidase system.
Ratio estimation of mortality using catch curves

Abstract A ratio estimator for calculation of mortality from catch curves is developed in which the individual net hauls are treated as samples, as they should be, and precision depends on the number of net hauls and the average number of fish caught per net haul; this permits calculation of the sample sizes necessary to obtain desired levels of precision in terms of the number of net hauls and mean number of fish per net haul. The ratio estimator is compared with the Chapman-Robson maximum likelihood estimator and the least-squares estimator.
Large-scale surface to surface transport for photons and electrons via Monte Carlo

Abstract A brief history of Monte Carlo methods is presented, with a differentiation between uses in engineering versus physics, indicating different computational approaches in each field. Particle tracing is presented for photons and then electrons in the presence of a uniform magnetic field. Next, a comprehensive formulation is presented for particle-material interactions, including absorptance, transmittance, and three models of reflectance: diffuse, specular, and semi-specular. Then, a discussion of event steps is presented, indicating that algorithms may be effectively vectorized. Vectorization results are analyzed using a modified version of Amdahl's Law, indicating that over 99% of the “work” of an algorithm may be vectorized.
Regulated expression of P210 Bcr-Abl during embryonic stem cell differentiation stimulates multipotential progenitor expansion and myeloid cell fate

P210 Bcr-Abl is an activated tyrosine kinase oncogene encoded by the Philadelphia chromosome associated with human chronic myelogenous leukemia (CML). The disease represents a clonal disorder arising in the pluripotent hematopoietic stem cell. During the chronic phase, patients present with a dramatic expansion of myeloid cells and a mild anemia. Retroviral gene transfer and transgenic expression in rodents have demonstrated the ability of Bcr-Abl to induce various types of leukemia. However, study of human CML or rodent models has not determined the direct and immediate effects of Bcr-Abl on hematopoietic cells from those requiring secondary genetic or epigenetic changes selected during the pathogenic process. We utilized tetracycline-regulated expression of Bcr-Abl from a promoter engineered for robust expression in primitive stem cells through multilineage blood cell development in combination with the in vitro differentiation of embryonal stem cells into hematopoietic elements. Our results demonstrate that Bcr-Abl expression alone is sufficient to increase the number of multipotent and myeloid lineage committed progenitors in a dose-dependent manner while suppressing the development of committed erythroid progenitors. These effects are reversible upon extinguishing Bcr-Abl expression. These findings are consistent with Bcr-Abl being the sole genetic change needed for the establishment of the chronic phase of CML and provide a powerful system for the analysis of any genetic change that alters cell growth and lineage choices of the hematopoietic stem cell.
Implementation of a Critical Pathway for Complicated Gallstone Disease: Translation of Population-Based Data into Clinical Practice

Background Evidence-based guidelines recommend cholecystectomy during initial hospitalization for complicated gallstone disease. Previous studies and quality initiative data from our institution demonstrated that only 40% to 75% of patients underwent cholecystectomy on index admission. Study Design In January 2009, we implemented a critical pathway to improve cholecystectomy rates for all patients emergently admitted for acute cholecystitis, mild gallstone pancreatitis, or common bile duct stones. We compared cholecystectomy rates during initial hospitalization, time to cholecystectomy, length of initial stay, and readmission rates in prepathway (January 2005 to February 2008) and postpathway patients (January 2009 to May 2010). Results Demographic and clinical characteristics were similar between prepathway (n = 455) and postpathway patients (n = 112). Cholecystectomy rates during initial hospitalization increased from 48% to 78% after pathway implementation (p Conclusions Implementation of a multidisciplinary critical pathway improved cholecystectomy rates on initial hospitalization and lowered costs by shortening length of stay and markedly decreasing readmission rates for gallstone-related problems. Broader implementation of similar pathways offers the potential to translate evidence-based guidelines into clinical practice and minimize the cost of medical care.
Fatty Acid Composition of Backfat, Intermuscular, Kidney Pelvis and Heart Fat and Tail Fat of Angus Cross Steers Finished on Grass or High Grain Diets

Fatty acid profiles of backfat (BF), intermuscular fat (IMF), kidney pelvic heart (KPH) fat and tail fat (TF) depots from 15-mo old Angus cross steers finished on grass (GS; n = 18) were compared to those finished on a grain diet (GN ; n = 14) to examine how diet and fat depot impacts fatty acid composition. GS steers grazed an average of 10 months (mo) on ryegrass and white clover irrigated pasture and GN finished steers were a corn based finishing diet for 4 mo. Overall, fat from GS steers contained higher percentages of C6:0 (P = 0.008), C12:0 (P = 0.003), C14:0 (P = 0.001), C16:0 (P = 0.002), C18:3 (P = 0.008), C20:0 (P < 0.001), C18:1 trans9 (P = 0.004), C18:2 cis9 cis12 (P < 0.001) and C18:2 trans9 trans12 (P < 0.001) than GN steers. Fat from GN steers contained higher percentages of C18:0 (P < 0.001). For both GS and GN steers, C18:0 content was higher in the KPH and IMF compared to BF and TF (P = 0.015) depots and C18:1 cis9 content was lower in KPH compared to BF and TF depots (P < 0.001). Therefore, fatty acid composition differs due to diet and differs across depots. Manipulating diets and source of fat (depot) could be used as strategies to modify the fatty acid composition of meat products to increase health benefits to consumers.