cssi/SciSciGPT-SciSciNet huggingface dataset:
Enhanced detection of polymorphic DNA by multiple arbitrary amplicon profiling of endonuclease-digested DNA: identification of markers tightly linked to the supernodulation locus in soybean.

Multiple endonuclease digestion of template DNA or amplification products can increase significantly the detection of polymorphic DNA in fingerprints generated by multiple arbitrary amplicon profiling (MAAP). This coupling of endonuclease cleavage and amplification of arbitrary stretches of DNA, directed by short oligonucleotide primers, readily allowed distinction of closely related fungal and bacterial isolates and plant cultivars. MAAP analysis of cleaved template DNA enabled the identification of molecular markers linked to a developmental locus of soybean (Glycine max L. Merrill). Ethyl methane sulfonate (EMS)-induced supernodulating, near-isogenic lines altered in the nts locus, which controls nodule formation, could be distinguished from each other and from the parent cultivar by amplification of template pre-digested with 2–3 restriction enzymes. A total of 42 DNA polymorphisms were detected using only 19 octamer primers. In the absence of digestion, 25 primers failed to differentiate these soybean genotypes. Several polymorphic products co-segregated tightly with the nts locus in F2 families from crosses between the allelic mutants nts382 and nts1007 and the ancestral G. soja Sieb. & Succ. PI468.397. Our results suggest that EMS is capable of inducing extensive DNA alterations, probably around discrete mutational hot-spots. EMS-induced DNA polymorphisms may constitute sequence-tagged markers diagnostic of specific genomic regions.
Revival of CD8+ Treg–mediated suppression

Despite their first recognition almost 40 years ago, CD8(+) 'suppressor' T cells remain poorly characterized. Recent studies of these lymphocytes, now popularly referred to as regulatory CD8(+) T cells (CD8(+) Tregs), have helped clarify their important role in the regulation of autoimmune disease. Here, we review progress related to the identification, phenotype and function of CD8(+) Tregs. We also focus on a newly described subset, CD8alphaalpha(+)TCRalphabeta(+) Tregs, which in mice recognize a T-cell receptor-derived peptide in the context of the class Ib major histocompatibility complex molecule Qa-1. These Tregs target only activated T cells and complement the suppression provided by CD4(+)Foxp3(+) Tregs. Investigations leading to the detailed identification, expansion, maintenance and function of CD8alphaalpha(+) Tregs should result in new therapeutic strategies for human inflammatory diseases.
Ionic content of the neuroglia

Abstract Neuronal degeneration in the lateral geniculate bodies of cats was induced by unilateral ablation of the visual cortex and bilateral enucleation. Four months later, the neurons had disappeared almost completely from the lateral geniculate ipsilateral to the cortical ablation, and there was only slight mesenchymal reaction. The water, sodium, potassium and chloride contents were determined in fresh samples of lateral geniculate bodies which were normal, contained transneuronal degeneration (contralateral to cortical lesion), or contained both transneuronal and retrograde degeneration (ipsilateral to cortical lesion). Considered in relation to the small interstitial spaces seen in electron micrographs, the data indicate that the concentrations of chloride and sodium in the neuroglia are high, but that the concentration of potassium is about the same as in neurons. Such findings are compatible with the view that neuroglia cells are low-voltage cells containing some cations not present as free ions.
Use of fluorosilicone to unfold a giant retinal tear

We unfolded and attached a giant retinal tear with an inverted edge using fluorosilicone oil while the patient was in the supine position. The advantages of high viscosity (10,000 centistokes) and specific gravity (1.31) fluorosilicone are discussed in this paper.
Altering school climate through school-wide Positive Behavioral Interventions and Supports: findings from a group-randomized effectiveness trial.

Positive Behavioral Interventions and Supports (PBIS) is a universal, school-wide prevention strategy that is currently implemented in over 7,500 schools to reduce disruptive behavior problems. The present study examines the impact of PBIS on staff reports of school organizational health using data from a group-randomized controlled effectiveness trial of PBIS conducted in 37 elementary schools. Longitudinal multilevel analyses on data from 2,596 staff revealed a significant effect of PBIS on the schools’ overall organizational health, resource influence, staff affiliation, and academic emphasis over the 5-year trial; the effects on collegial leadership and institutional integrity were significant when implementation fidelity was included in the model. Trained schools that adopted PBIS the fastest tended to have higher levels of organizational health at baseline, but the later-implementing schools tended to experience the greatest improvements in organizational health after implementing PBIS. This study indicated that changes in school organizational health are important consequences of the PBIS whole-school prevention model, and may in turn be a potential contextual mediator of the effect of PBIS on student performance.
Computer simulation of metal thin-film epitaxy

Abstract We present a review of our molecular-dynamics simulation studies of kinetic mechanisms in Au Ag (110) heteroepitaxy and Pt Pt (111) homoepitaxy. Novel and complicated microscopic kinetic phenomena have been revealed, which help to resolve the origins of the unconventional growth modes in these systems.
Cause of Death in Older Patients with Anatomo-Pathological Evidence of Chronic Bronchitis or Emphysema: A Case-Control Study Based on Autopsy Findings

OBJECTIVES: To determine the most frequent causes of death of hospitalized older patients based on anatomo-pathological evidence and to compare the relative frequency of fatal events between patients with and without evidence of either chronic bronchitis (CB) or emphysema (E). DESIGN: Retrospective, case-control study based on a computerized database including anatomo-pathological data of patients deceased and autopsied over a 25-year period. SETTING: Two geriatric hospitals in Geneva. PARTICIPANTS: Not applicable. MEASUREMENTS: Autopsy records for cause(s) of death in patients with CB or E. RESULTS: 3,685 patients deceased in our institution (1,540 men; 2,145 women) were autopsied between 1972 and 1996; mean age at death was 81.5 +/- 8.0 years. Anatomo-pathological evidence of CB or E was found in 983 patients (26.6% of total); 262 (7.2%) had predominantly CB, and 456 (12.3%) predominantly E. Pneumonia was the most frequent cause of death in all patients (21.8%). Myocardial infarction (MI) (17.6% vs 14%), and respiratory failure (5.1% vs 1.5%) occurred more frequently in subjects with CB and/or E than in controls. Fatal pulmonary embolism (PE) was more frequent in patients with E (18.4%) than in patients with CB (10.7%; odds ratio ( OR) = 1.89, P =.008), or in controls (12.7%; OR = 1.56, P =.0008). CONCLUSION: Anatomo-pathological evidence of CB or E is highly prevalent in older patients, suggesting that CB and E are clinically underdiagnosed in this age group. Fatal MI occurred significantly more frequently in older patients with E or CB than in controls. Furthermore, patients with E were at significantly higher risk of fatal PE than patients with CB or controls.
Reactivity of acyclic (pentadienyl)iron(1+) cations: Synthetic studies directed toward the frondosins

A short, 4-step route to the scaffold of frondosin A and B is reported. The [1-methoxycarbonyl-5-(2′,5′-dimethoxyphenyl)pentadienyl]Fe(CO)3+ cation was prepared in two steps from (methyl 6-oxo-2,4-hexadienoate)Fe(CO)3. Reaction of this cation with isopropenyl Grignard or cyclohexenyllithium reagents affords (2-alkenyl-5-aryl-1-methoxycarbonyl-3-pentene-1,5-diyl)Fe(CO)3 along with other addition products. Oxidative decomplexation of these (pentenediyl)iron complexes, utilizing CuCl2, affords 6-aryl-3-methoxycarbonyl-1,4-cycloheptadienes via the presumed intermediacy of a cis-divinylcyclopropane.
The effect of adults' eating on young children's acceptance of unfamiliar foods

Abstract Adults presented unfamiliar foods to 14- to 20- and 42- to 48-month-old children individually in their homes. More children put the food in their mouths when the adults also were eating than when the adults simply were offering the food. More children put food in their mouths when their mothers were the source than when the source was a friendly adult “visitor”. However, even when alone with a child, the visitor's eating elicited reliably more tasting. Analysis of requesting behavior indicated that the adults' eating aroused a desire to eat in the children. There were no consistent sex differences or interactions between sex of visitor and sex of child in children's food acceptance. There was a suggestion that younger children were more affected by repeated offerings than were older children. It is concluded that a relatively “low level” form of observational learning—“social facilitation”—can account for the data.
Theory of x-ray absorption by laser-aligned symmetric-top molecules

We devise a theory of x-ray absorption by symmetric-top molecules which are aligned by an intense optical laser. Initially, the density matrix of the system is composed of the electronic ground state of the molecules and a thermal ensemble of rigid-rotor eigenstates. We formulate equations of motion of the two-color (laser plus x rays) rotational-electronic problem. The interaction with the laser is assumed to be nonresonant; it is described by an electric dipole polarizability tensor. X-ray absorption is approximated as a one-photon process. It is shown that the equations can be separated such that the interaction with the laser can be treated independently of the x rays. The laser-only density matrix is propagated numerically. After each time step, the x-ray absorption is calculated. We apply our theory to study adiabatic alignment of bromine molecules $({\text{Br}}_{2})$. The required dynamic polarizabilities are determined using the ab initio linear response methods coupled-cluster singles (CCS), second-order approximate coupled-cluster singles and doubles (CC2), and coupled-cluster singles and doubles (CCSD). For the description of x-ray absorption on the ${\ensuremath{\sigma}}_{g}1s\ensuremath{\rightarrow}{\ensuremath{\sigma}}_{u}4p$ resonance, a parameter-free two-level model is used for the electronic structure of the molecules. Our theory opens up novel perspectives for the quantum control of x-ray radiation.
The Bab al Mandab vs the Nile-Levant: An Appraisal of the Two Dispersal Routes for Early Modern Humans Out of Africa

There is a growing convergence of paleontological, archaeological and genetic evidence for the African origin of modern humans and their successive dispersals. However, there is disagreement about the route or routes taken by early humans during their migration out of Africa. This article examines the Middle Paleolithic/Middle Stone Age archaeological evidence from the Horn of Africa, the Nile Valley/eastern Sahara, the Arabian Peninsula and the Levant, and assesses their relevance to this question. Specific reduction techniques and typological variables are used to compare industries across these regions. This study shows that there are more evident technological and typological similarities among assemblages from the Horn, the Nile Valley and Arabia than between any of these regions and the Levant. Il y a plusieurs preuves paleontologiques, archeologiques et genetiques qui supportes une origine Africaine pour l’Homme moderne, et qui indiques les migrations de l’Homme hors de ce continent. Cependant, les parcours precis suivis par ces anciennes populations en route pour l’Europe et l’Asie ne sont pas evidents. Cette etude a comme but d’examiner les preuves archeologiques du Paleolithique moyen et de l’Âge de la Pierre moyen (MSA) de la corne de l’Afrique, la vallee du Nile, le desert Sahara de l’est, la peninsule Arabe, et du Moyen Orient pour determiner les contributions de ces regions a la migration de l’Homme modern hors de l’Afrique. Les techniques de reduction de pierre et quelques donnees typologiques sont utilisees pour comparer les ensembles lithiques des regions traverses par la Route du Nord et la Route du Sud. Si les resultats de ces comparaisons demontrent que les donnees typologiques et les techniques de reduction sont semblables entre les regions d’un des parcours, nous pourrons inferer qu’il existait dans le passe soit un lien culturel entre ces regions, ou des paralleles dans le comportement de ces peuples anciens. Les resultats de cette etude demontrent qu’il y a plus de resemblances avec les techniques de reduction et les donnees typologiques dans les ensembles lithiques de la corne de l’Afrique, la vallee du Nile, et la penisule Arabe compares aux ensembles du Moyen Orient, ce qui soutien l’hypothese d’une migration par la Route du Sud.
Structure–property relationship in fibers spun from poly(ethylene terephthalate) and liquid crystalline polymer blends. I. The effect of composition and processing on fiber morphology and properties

Poly(ethylene terephthalate) (PET) matrix was modified by blending with a specially prepared thermotropic liquid crystalline polymer (TLCP), in the hope to make the in situ composite during fiber spinning. It has been found that the TLCP did not fibrillate in the PET matrix at any concentration under given processing conditions, although it did in the polycarbonate matrix. This was explained by the low interaction parameter (low surface tension) and partial degree of mixing of PET and TLCP. The TLCP was an excellent processing aid even at very low concentrations, but it had an adverse effect on the strength of highly drawn fibers. The modulus of both undrawn and highly drawn fibers increases slightly with increasing TLCP concentration. © 1995 John Wiley & Sons, Inc.
Effect of biliary obstruction on canine plasma and biliary lipids.

The common bile duct was obstructed in 17 dogs. Reciprocal changes were noted for the plasma and biliary lipid concentrations of each after obstruction. As the plasma lecithin and free cholesterol concentrations increased, the biliary lipid concentrations declined. After biliary obstruction the reflux of biliary lecithin into the plasma of these animals was demonstrated with both labeled and unlabeled lecithin. The plasma lipid abnormalities seen after acute biliary obstruction were closely simulated by the reflux of lecithin alone from the biliary tree. The isolated reflux of biliary tract taurocholate produced a distinct lowering of plasma phospholipid and cholesterol concentrations, quite different from the plasma lipid alteration noted with acute biliary obstruction. Similar to observations in human obstruction, some of the plasma lipid was in mesophase form after these animals were obstructed.
In vitro drug testing of ovarian cancer using the human tumor colony-forming assay: comparison of in vitro response and clinical outcome.

The purpose of this study was to assess the prognostic value of in vitro drug chemosensitivity testing using the Hamburger-Salmon human tumor colony-forming assay (HTCA) in fresh tumor samples obtained from newly diagnosed patients with stage II-IV ovarian cancer undergoing maximum cytoreductive surgery and prior to platinum-based chemotherapy. The HTCA was performed on fresh ovarian cancers obtained from 93 patients at their initial exploratory laparotomy to evaluate in vitro sensitivity to cisplatin, carboplatin, and cyclophosphamide following a 1-hr drug exposure. Prospective clinical follow-up was performed on all patients with the primary study endpoints being pathologically proven complete response at second-look surgery and disease-free and overall survival durations. In vitro drug sensitivity was strongly dose-dependent. At a concentration of 5 micrograms/ml only 23% of tumor samples were sensitive (as defined by a > or = 50% decrease in tumor colony-forming units compared to controls) to cisplatin; 13% of tumors were sensitive to carboplatin at a concentration of 50 micrograms/ml and 11% to 4-OH-cyclophosphamide at a concentration of 1 microgram/ml. At doses which were 10 times the previously stated concentrations, the sensitivity rates to cisplatin, carboplatin, and 4-OH-cyclophosphamide increased to 72, 63, and 53%, respectively. Subjects were categorized as having drug-sensitive disease if HTCA results showed in vitro drug sensitivity to at least one of the agents used in their primary chemotherapy. Multivariate analysis failed to show any advantage in clinical response rate, progression-free interval, or survival duration for patients with drug-sensitive disease compared to drug-resistant disease; however, there was evidence of a trend toward an enhanced pathologically proven complete response rate in patients who had chemosensitive tumors in vitro. Second-look surgery was performed in 28 of 55 patients with optimal surgical resections and no clinical evidence of disease at the completion of their primary chemotherapy. Fifty percent (5/10) of patients with drug-sensitive disease achieved a pathologic complete response, while only 3/18 (17%) patients with drug-resistant tumors had a documented pathologic complete response (P = 0.13). As reported in other ovarian cancer studies, patient characteristics which were found to be significantly associated with survival were stage of disease (II-III vs IV), optimal primary surgical resection (i.e., < 1 cm2 residual tumor) vs suboptimal resection, clinical measurability of disease at initiation of chemotherapy, and response to primary chemotherapy. In conclusion, in vitro drug sensitivity, as measured by the HTCA, does not appear to be an independent prognostic factor for survival in patients with stage II-IV epithelial ovarian cancer who undergo standard treatment with tumor debulking surgery and primary platinum-based chemotherapy.(ABSTRACT TRUNCATED AT 400 WORDS)
Soliton reflection and transmission at an interface

Abstract A general reflection-transmission criterion is derived for KdV and NLS solitons at an interface between two regions. The criterion successfully satisfies laboratory experiments performed in a plasma for KdV solitons and numerical experiments describing a nonlinear optical interface for NLS solitons. It also correctly describes linear waves.
Tubulin Targeting Agents

Abstract Drugs that target tubulin, including the vinca alkaloids and taxanes, represent some of the most effective anticancer medications. Both natural-product and semisynthetic compounds show a remarkable spectrum of anticancer activity. In this chapter, we review new developments in cancer biology and pharmacology that shed light on the effectiveness of tubulin binding agents. In addition, we highlight newer agents and several drugs in preclinical development that hold considerable promise for the future. Finally, we comment on the rational selection of patients for chemotherapy and a more mechanistic approach to using these drugs in combinations.
Nanomechanical mapping of the osteochondral interface with contact resonance force microscopy and nanoindentation

The bone-cartilage, or osteochondral, interface resists remarkably high shear stresses and rarely fails, yet its mechanical characteristics are largely unknown. A complete understanding of this hierarchical system requires mechanical-property information at the length scales of both the interface and the connecting tissues. Here, we combined nanoindentation and atomic force microscopy (AFM) methods to investigate the multiscale mechanical properties across the osteochondral region. The nanoindentation modulus M ranged from that of the subchondral bone (M=22.8±1.8GPa) to that of hyaline articular cartilage embedded in PMMA (M=5.7±1.0GPa) across a narrow transition region <5μm wide. Contact resonance force microscopy (CR-FM), which measures the frequency and quality factor of the AFM cantilever's vibrational resonance in contact mode, was used to determine the relative storage modulus and loss tangent of the osteochondral interface. With better spatial resolution than nanoindentation, CR-FM measurements indicated an even narrower interface width of 2.3±1.2μm. Furthermore, CR-FM revealed a 24% increase in the viscoelastic loss tangent from the articular calcified cartilage into the PMMA-embedded hyaline articular cartilage. Quantitative backscattered electron imaging provided complementary measurement of mineral content. Our results provide insight into the multiscale functionality of the osteochondral interface that will advance understanding of disease states such as osteoarthritis and aid in the development of biomimetic interfaces.
What Does American History Tell Us about Katrina and Vice Versa

Natural disasters invariably provoke a range of reactions. Bereavement mingles with an ger. The need to commemorate competes with the urge to blame. Boosterism gets a boost. No matter how deep the ash or how high the rubble, you will always find a politician or business leader promising to bring back a just-ruined city bigger and better than before. Storms, fires, earthquakes, mudslides?these are mere blessings in disguise. What was broken, dysfunctional, and decrepit has been leveled or swept away. Now, long-overdue improvements can finally be launched. The optimistic narratives of resilience and resur rection, so necessary for marshaling the will and the capital to rebuild in the teeth of catastrophe, fill the pages of American urban history. They resounded after the great Chicago fire of 1871 and the Galveston hurricane of 1900. In San Francisco after the earthquake and fire of 1906, local boosters styled themselves "regenerators," to let people know they were as interested in purification as in rebuilding.1 Mayor C. Ray Nagin of New Orleans's pledge to restore the waterlogged metropolis to all its former grandeur, and then some, echoed that language of rebirth and renewal. The businessmen and de velopers, civic leaders and college presidents, who dominated his Bring New Orleans Back Commission (bnobc) repeated it as well, even as many of them favored shrinking the city's footprint. President George W. Bush paid boosterism the ultimate compliment when he told a national television audience from a mostly darkened French Quarter sev enteen days after the storm: "We will not just rebuild, we will build higher and better."2 Natural disasters also have political effects. Without fail they shift the ground of lo cal politics. The looting that inevitably follows catastrophe triggers repressive measures. To restore law and order, the militia comes to town. The police are told to shoot to kill. Vigilantes are given license. In a short time, the assault on civil liberties elicits a demo cratic backlash, if not challenges in the courts. Then there is the political opportunism of the business community, which tends to view crises as terrible things to waste. Good
Analysis of EPR data characterized by a spin Hamiltonian with large off-diagonal elements

Abstract A method is presented for the computer analysis of electron paramagnetic resonance (EPR) data. It is particularly useful when the off diagonal terms in the spin Hamiltonian are large. The main features are: (i) simultaneous variation of all parameters in the spin Hamiltonian having the same order of magnitude, and (ii) simultaneous consideration of resonant magnetic field values corresponding to more than one orientation of the external magnetic field. The superiority of the present method is illustrated numerically by analyzing the room-temperature EPR data for Gd 3+ in SMCl 3 ·6H 2 O and comparing the results with those obtained using other methods of analysis.
Acetonitrile complexes of triply charged metal ions: are ligated trications intrinsically more prone to charge reduction than dications?

Abstract The development of electrospray has enabled the generation of gas-phase solvated multiply charged metal ions. Complexes involving both protic ligands (water, alcohols) and aprotic ones (e.g., ketones, DMSO, acetonitrile) were found for dications, but trications were compatible with aprotic ligands only. Here, to probe this difference in stability, acetonitrile complexes of metal trications were formed by ESI and collisionally fragmented. Proton transfer, electron transfer, and heterolytic cleavage channels previously found for dications were observed. Characteristic sizes for these processes suggest an intrinsic gap in the stability of dication and trication complexes against proton transfer, but not against electron transfer.
Monitoring of Vapor-Induced Phase Separation during Spin Coating of PVDF by Optical Scattering

Solutions of poly(vinylidene fluoride) (PVDF) and dimethyl sulfoxide (DMSO) were spin cast under varying relative humidity environments. To elucidate film formation mechanisms, in situ optical scattering was used to monitor the physical processes occurring during spin coating. SEM micrographs and optical scattering taken together show that vapor-induced phase separation (VIPS) is a process that controls morphology during spin coating. Time periods were identified in the optical scattering patterns allowing for real time identification of phase separation for greater process control.
The Paucity of Effects in Community Trials: Is Secular Trend the Culprit?

Background. The most recent major U.S. trials that evaluated community-level programs to influence risk factors and health behaviors identified secular trends in the risk factors and health behaviors among the factors that might have limited community-level effects. The research reported in this paper uses data from one of the trials to examine the secular trend explanation directly. Methods. Data from the 22-community Community Intervention Trial for Smoking Cessation (COMMIT) were analyzed to test a hypothesis based on secular trend reasoning: program effects for smoking prevalence were larger for treatment communities matched to control communities with small declines in smoking than in treatment communities matched to control communities with larger declines in smoking. Results. Consistent with the secular trend explanation, program effects were larger when control communities had relatively small declines in smoking prevalence. Conclusions. The findings suggest that secular trends masked community-level program effects in COMMIT.
Hyperspectral object tracking using small sample size

This paper introduces a simple approach for object tracking using hyperspectral (HS) spectral features. The approach addresses the object tracking problem using a small object sample size. For a particular application, the key challenges are: (i) Offline training cannot be utilized; (ii) motor vehicles of interest (targets) have a small sample size (e.g., less than 9); and (iii) kinematic states of targets cannot be used for tracking, since stationary targets are also of interest. Using HS imagery, this paper introduces a method that exploits the mean and median averages spectra to estimate higher moments of the underlying (and unknown) probability distribution function of spectra; in particular, skew tendency and sign. Tracking HS targets is then possible using this algorithm to test a sequence of HS imagery, given that target spectra are initially cued by the user. The approach was implemented into a commercially off the shelf workstation, featuring the IBM Cell Processor and GA-180 Add in Board. Preliminary results are promising using a challenging HS data cube.
An analysis of atmospheric CH 4 concentrations from 1984 to 2008 with a single box atmospheric chemistry model

Abstract. We present a single box atmospheric chemistry model involving atmospheric methane (CH 4 ), carbon monoxide (CO) and radical hydroxyl (OH) to analyze atmospheric CH 4 concentrations from 1984 to 2008. When OH is allowed to vary, the modeled CH 4 is 20 ppb higher than observations from the NOAA/ESRL and AGAGE networks for the end of 2008. However, when the OH concentration is held constant at 10 6 molecule cm −3 , the simulated CH 4 shows a trend approximately equal to observations. Both simulations show a clear slowdown in the CH 4 growth rate during recent decades, from about 13 ppb yr −1 in 1984 to less than 5 ppb yr −1 in 2003. Furthermore, if the constant OH assumption is credible, we think that this slowdown is mainly due to a pause in the growth of wetland methane emissions. In simulations run for the Northern and Southern Hemispheres separately, we find that the Northern Hemisphere is more sensitive to wetland emissions, whereas the southern tends to be more perturbed by CH 4 transportation, dramatic OH change, and biomass burning. When measured CO values from NOAA/ESRL are used to drive the model, changes in the CH 4 growth rate become more consistent with observations, but the long-term increase in CH 4 is underestimated. This shows that CO is a good indicator of short-term variations in oxidizing power in the atmosphere. The simulation results also indicate the significant drop in OH concentrations in 1998 (about 5% lower than the previous year) was probably due to an abrupt increase in wetland methane emissions during an intense EI Nino event. Using a fixed-lag Kalman smoother, we estimate the mean wetland methane flux is about 128 Tg yr −1 through the period 1984–2008. This study demonstrates the effectiveness in examining the role of OH and CO in affecting CH 4 .
Leghaemoglobin oxygenation gradients in alfalfa and yellow sweetclover nodules

Respiration in support of N 2 fixation by rhizobia in legume root nodules depends on an adequate supply of O 2 , but excessive O 2 can damage nitrogenase, the key enzyme. The movement of O 2 into and within the nodule is driven by gradients in the concentration of O 2 or in the oxygenation of the O 2 -carrier, leghaemoglobin. Steeper gradients may increase flux to the sites of respiration, but gradients also raise the possibility of inadequate O 2 in some nodule zones and excessive O 2 in others. No detailed study of O 2 gradients in the interior of nodules has been published previously. Spectral changes in leghaemoglobin with oxygenation, previously used to measure the average O 2 status of the nodule interior, were used to map longitudinal gradients in O 2 and in respiratory capacity in the elongated nodules of alfalfa (Medicago sativa L.) and sweetclover (Melilotus officinalis L.). Variability among nodules under air in the magnitude and direction of internal O 2 gradients was seen in both species. Despite consistently higher respiratory capacity near the meristematic tip, a majority of nodules had higher O 2 towards the tip than towards the base. These results contrast with a previous report, apparently based on limited data, but they are consistent with anatomical and tracer studies showing higher gas permeability near the tip.
Cinematographical Studies, 1930–1939: An Overlooked Decade

Biomechanical researchers who analyze data collected cinematographically usually acknowledge the work of late 19th-century cinematographers Eadweard Muybridge (United States and England), Etienne J. Marey (France), Christian W. Braune, and Otto Fisher (Germany). The acknowledgement is then typically followed by a review of the current literature. But most of these studies delete the significant “middle generation” of cinematographers—1930–1939—a particularly fruitful decade during which motion pictures were used to help identify biomechanical principles. This discussion will focus on the cinematographical studies of W.O. Fern, H. Elftman, R.B. Glassow, E. Jokl, and T.K. Cureton, who have given biomechanics a rich legacy and helped define the discipline as it exists today.
In vivo protein expression from mRNA delivered into adult rat brain

The expression of proteins after local mRNA delivery has a great potential for analysis of protein function in vivo. To explore the feasibility of such a technique within the central nervous system (CNS), we delivered luciferase-encoding mRNA into the rat brain. The tissue distribution and stability of injected mRNA were analyzed using in situ detection and Northern hybridization, while luciferase expression was measured by enzymatic assay. Following intracerebral injection of lipofectin-complexed mRNA, expression of luciferase was detectable as early as 1 h, was maximal at 2-3 h, but was below the level of detection by 24 h. The extent of luciferase expression correlated with the amount of mRNA delivered. Luciferase expression was higher when lipofectin-complexed rather than naked mRNA was injected. In addition, the luciferase expression increased significantly by adding a 50 nt-long poly(A) tail to the 3'-end of the mRNA. Delivering mRNA to the cerebral cortex or hippocampus resulted in measurable luciferase activity at the injection sites but not in adjacent areas. Accordingly, the luciferase mRNA was also localized to the injection site, and the amount of intact transcript was significantly higher at 3 h compared to 24 h after injection. These results demonstrate that in vivo mRNA delivery is a feasible technique for immediate, transient overexpression of desired proteins in the CNS and, therefore, can serve as a model system to study the neurobiological effects of specific proteins.
Low-frequency distortion product otoacoustic emissions in two species of kangaroo rats: implications for auditory sensitivity.

Low-frequency distortion-product otoacoustic emissions were measured in two species of kangaroo rats to test the prediction that a large footdrumming species (e.g., Dipodomys spectabilis) would have greater distortion-product otoacoustic emission amplitude than a small non-footdrumming species (e.g., Dipodomys merriami), indicating better hearing sensitivity at low frequencies. Equal-level (65 dB SPL) stimulus tones (f1, f2), presented over a (f1) range of 200–1000 Hz, were used to evoke the 2f1−f2 distortion-product otoacoustic emission. Mean 2f1−f2 levels for D. merriami showed good correspondence to previously published audiograms for that species. Mean 2f1−f2 levels and 95% confidence intervals indicated species differences below 400 Hz, supporting the theory that low-frequency hearing sensitivity is better in large kangaroo rat species. These results suggest that the size-related divergence in footdrumming behavior may be related to differential auditory sensitivity.
Combustion diagnostics: Planar imaging techniques

New measurement techniques based on planar (2-d) imaging of scattered light provide a powerful complement to single-point laser-based diagnostics, with significant potential to impact combustion research. Though still in an early stage of development, these imaging methods offer prospects for non-invasive, spatially and temporally resolved measurements of species concentrations and moler fractions, temperature, density, velocity, and pressure. Imaging processes encompassed in this review include laser-induced fluorescence and Raman, Mie and Rayleigh scattering. Extensions of these 2-d techniques to new flowfield variables and species, and to 3-d imaging by rapid scanning of the illumination plane, are already in progress.
Silver Pellets for Improving Software Quality

In his timeless article, Fred Brooks asserted that the essential difficulties of developing software would continue to ensure the futility of any search for a "silver bullet" to reproduce for software engineering the catalytic effects that electronics, transistors, and large-scale integration had on computer hardware development. Since his article, software development has become even more difficult and organizations have magnified the struggle to overcome what has been called "the software crisis." There is unlikely to be a silver bullet, but this article discusses a variety of user-centered and process-oriented systems delivery methods, philosophies, and techniques available to the software engineering community, that may be used in innovative permutations to tranquilize the dragon of poor software quality. The context for the applicability of these approaches and some advantages and weaknesses where indicated in the research literature or gleaned from practitioner accounts are also discussed.
Selective knockdown of mutant SOD1 in Schwann cells ameliorates disease in G85R mutant SOD1 transgenic mice

Mutants of superoxide dismutase type 1 (mtSOD1) that have full dismutase activity (e.g., G37R) as well as none (e.g., G85R) cause familial amyotrophic lateral sclerosis (FALS), indicating that mtSOD1-induced FALS results from a toxicity rather than loss in SOD1 enzymatic activity. Still, it has remained unclear whether mtSOD1 dismutase activity can influence disease. A previous study demonstrated that Cre-mediated knockdown of G37R expression in Schwann cells (SCs) of G37R transgenic mice shortened the late phase of disease and survival. These results suggested that the neuroprotective effect of G37R expressed in SCs was greater than its toxicity, presumably because its dismutase activity counteracted reactive oxygen species (ROS). In order to further investigate this, we knocked down G85R in SCs by crossing G85R(flox) mice with myelin-protein-zero (P(0)):Cre mice, which express Cre recombinase in SCs. Knockdown of G85R in SCs of G85R mice delayed disease onset and extended survival indicating that G85R expression in SCs is neurotoxic. These results demonstrate differences in the effect on disease of dismutase active vs. inactive mtSOD1 suggesting that both a loss as well as gain in function of mtSOD1 influence FALS pathogenesis. The results suggest that mtSOD1-induced FALS treatment may have to be adjusted depending on the cell type targeted and particular mtSOD1 involved.
Reconstruction and sampling constraints for spiral data (image processing)

The author addresses the problem of reconstructing a circularly bandlimited two-dimensional function from its samples on a general spiral contour. The spiral data are represented in terms of evenly spaced samples from a nonlinear two-dimensional transformation of the Cartesian coordinates. This transformation makes it possible to use unified Fourier reconstruction sampling principles to obtain accurate reconstruction based on a set of constraints imposed on the spiral parameters. The results are then utilized to develop efficient sampling strategies for the linear class of spirals, the spiral of Archimedes. Sampling efficiency for spiral data, analogous to the sampling efficiencies of hexagonally and rectangularly sampled data, is defined. A sampling scheme on a spiral is introduced that possesses a uniform sampling efficiency comparable to the sampling efficiency of rectangularly sampled data. >
On a theorem of Kummer

Abstract The author gives a simple proof of a theorem of Kummer. Let q denote an odd prime, e = (q − 1) 2 and let fe(x) denote the polynomial with leading coefficient 1 whose roots are 2 cos ( 2mπ q ) with 1 ≤ m ≤ e. Then all prime divisors p of the polynomial fe(x) have the form p ≡ ± 1 (rmmod q), except for p = q.
Incoherent x-ray scattering factors calculated from impulse-approximation Compton profiles: A comparison with the Waller-Hartree theory

Incoherent x-ray scattering factors have been calculated for Li through Ne by integrating over Compton profiles calculated using the impulse approximation. Analytic expressions for the impulse-approximation Compton profiles (IACP) were derived from Clementi-Hartree-Fock (HF) analytic wave functions. Both experimental and theoretical HF electron binding energies were used in the numerical computation of the IACP inelastic scattering factors. These IACP scattering factors are compared with results obtained from the Waller-Hartree (WH) theory using HF atomic wave functions and a configuration-interaction (CI) wave function. Differences of as much as a factor of 2 are found at low scattering angles between the IACP and WH results calculated from HF wave functions. At low scattering angles the IACP results are in closer agreement with WH scattering factors calculated from the CI wave function than those computed from HF functions. A realistic possibility for obtaining more accurate inelastic scattering factors is demonstrated by direct integration over Compton profiles than can be computed from the WH scheme.
Cell proliferation in human atherosclerosis.

Despite the assumed proliferative nature of human atherosclerosis, very few studies exist that measure the actual proliferative rates in human arterial tissue. Recent proliferation-specific antibodies show very low rates of cell proliferation, as might be expected for a disease that takes numerous years to become clinically evident. These levels of proliferation are similar to animal models of hypercholesterolemia-induced atherosclerosis, and are unlike other models of acute mechanical injury to the artery wall. Proliferative activity in atherosclerotic plaques is seen among both smooth muscle cells and mononuclear inflammatory cells.
Clinical guides to preventing ethical conflicts between pregnant women and their physicians

We provide a justification for preventive ethics in obstetric practice. Four clinical guides to resolving ethical conflicts between pregnant women and their physicians can be identified: (1) informed consent as an ongoing dialogue between the pregnant woman and her physician, (2) negotiation as a clinical strategy, (3) respectful persuasion as a clinical strategy, and (4) the proper use of ethics committees.
Basic mechanisms of atrial fibrillation

The mechanism of AF remains controversial as support still exists for multiple wavelets, "mother rotor," and focal sources. These mechanisms need not be mutually exclusive. For example, the mother rotor hypothesis may not be distinct form the focal AF, if the rotor is of small size (ie, microre-entry). With the development of several animal models to study AF, along with improving technologies and mapping techniques, a further understanding of the pathophysiology of AF is being gained. Each animal model has unique electrophysiological and structural abnormalities, and one may not be able to generalize from one model to the next. It is likely that there is not one mechanism for all AF, but that there are substrate-specific mechanisms, and that AF may be comprised of several different mechanisms.
pH modulation of the kinetics of a Ca2+-sensitive cross-bridge state transition in mammalian single skeletal muscle fibres

1. The rate constant of tension redevelopment (ktr) following a rapid release and subsequent re-extension of muscle length has been demonstrated to be Ca2+ sensitive and is thought to reflect the rate-limiting step in the cross-bridge cycle leading to the formation of the strongly bound, force-bearing state. The kinetics of this cross-bridge state transition were investigated at 15 degrees C over a wide range of Ca2+ concentrations while varying pH from 7.00 to 6.20 in rat slow-twitch soleus, rat fast-twitch superficial vastus lateralis (SVL) and rabbit fast-twitch psoas skinned single fibres. 2. At maximal levels of Ca2+ activation, ktr was unaffected by changes in pH from 7.00 to 6.20 while isometric tension was depressed to 0.60 +/- 0.02 P0 (mean +/- S.E.M.) at the low pH in fast-twitch fibres and to 0.78 +/- 0.01 P0 in slow-twitch fibres (P0 is the maximum isometric tension obtained at pH 7.00). 3. At reduced levels of Ca2+ activation, corresponding to pCa (-log [Ca2+]) greater than 5.0, ktr was markedly depressed in all fibre types when pH was lowered. The Ca2+ sensitivity of steady-state isometric tension was also reduced in all fibres at pH 6.20 compared to pH 7.00. 4. The results suggest that pH has a modulatory effect upon an apparent rate constant which is rate limiting in terms of the formation of the strongly bound, force-bearing cross-bridge state. This effect of altered pH may in part account for the reduction in the Ca2+ sensitivity of isometric force at low pH as well as the depression of the rate of rise of tension in living fibres during fatiguing stimulation.
The Timoshenko Beam on an Elastic Foundation and Subject to a Moving Step Load, Part 2: Transient Response

The transient response of a simply supported semi-infinite Timoshenko beam on an elastic foundation to a moving step load is determined. The response is found from summing the solutions to two mutually complementary sets of governing equations. The first solution is a particular solution to the forced equations of motion. The second solution is a solution to a set of homogeneous equations of motion and nonhomogeneous boundary conditions so formulated as to satisfy the initial and boundary conditions of the actual problem when the two solutions are summed. As a particular solution, the steady-state solution is used which is the motion that would appear stationary to an observer traveling with the load. Steady-state solutions were developed in Part 1 of this article for all load speeds greater than zero. The solution to the homogeneous equations of motion is developed here in Part 2. It is shown that the latter solution can be obtained by numerical integration using the method of characteristics. Particular attention is given to the cases when the load travels at the critical speeds consisting of the minimum phase velocity ofpropagating harmonic waves and the sonic speeds. It is shown that the solution to the homogeneous equations combines with the steady-state solution in such a manner that the beam displacements are continuous and bounded for all finite times at all load speeds including the critical speeds. Numerical results are presented for the critical load speed cases.
Virtual Discussion: Understanding College Students' Electronic Bulletin Board Use

To investigate student and class characteristics associated with electronic bulletin board use, the authors analyzed a total of 3125 messages posted by students in 15 classes. Electronic postings were analyzed for intended audience, form, and content of the messages. Most messages included new information and did not specify a specific audience or recipient. However, student postings of messages specifically addressed to faculty were associated with higher course grades. Student postings in courses for which bulletin board use was optional posted more questions and comments directed to the faculty member than in courses in which bulletin board use was mandatory. Courses in which bulletin board use was mandatory produced more student messages offering social support to the faculty member, peer-directed questions, and peer-to-peer comments. Only faculty-directed comments and questions were associated with higher course grades.
Coarse-graining approximation for simulating surface reaction kinetics in particulate systems

When systems of reacting solid or liquid particles are explicitly modeled on a computational mesh, a wide distribution of initial particle sizes can lead to undesirably large numbers of mesh points. A coarse graining method is presented that avoids this problem by essentially grouping the finest particles together into a number of larger clusters. The excess surface area of these clusters is incorporated into a bias factor that can be multiplied by the intrinsic reaction rate constant to approximate the enhanced reaction rate of the clusters relative to actual particles of the same size. The bias factor can be calculated directly from knowledge of mesh point spacing and of the particle size distribution. Examples are given of the value that the bias factor can have for a model distribution of particle sizes, using computational meshes with varying resolution limits.
Hungary and the United States: A Comparison of Gifted Education

There is a lot that can be learned about a country based on the programs and provisions it has for mathematically talented students. While it is difficult to identify a single U.S. "program" or "approach" for gifted education, in general the trend is to put mathematically talented students through the standard mathematics sequence, just starting at an earlier age. In Hungary, on the other hand, the focus is on enrichment over acceleration. This paper explores how some very different historical, cultural, and political forces have shaped these two countries' different approaches to educating mathematically talented students.