cssi/SciSciGPT-SciSciNet huggingface dataset:
Flexible Environmental Regulation

“Flexible regulation” might sound like an oxymoron but it has become a widely accepted catch phrase for a pragmatic approach to regulation that promises the achievement of important public policy objectives at relatively low cost. Given the growing interest in flexible regulation in recent decades, we consider in this paper what can be learned from the U.S. experience with flexible environmental regulation. We assess four types of flexible regulation: (1) flexible commands, such as performance standards, information disclosure rules, and management-based regulations; (2) flexible targets, such as offsets, bubbles, and trading; (3) flexible consequences, such as voluntary programs and agreements; and (4) flexible regulators, such as systems of self-regulation and self-policing. Researchers have demonstrated that many flexible approaches can sometimes work, to some degree; but just as flexible policies can vary in form, we find that they also vary in results. What remains, we argue, is to determine whether the marginal and at times only potential gains from flexible forms of regulation are enough to justify their increased use.
High-resolution electron microscopy of BN on MgO: A model ceramic-ceramic interface

Abstract Studies of ceramic-ceramic interfaces by high-resolution electron microscopy have been facilitated by a novel approach to specimen preparation. Coatings of a variety of ceramics can be applied by various techniques to the surfaces of nonporous ceramic particles of simple geometric shape, and the resulting interfaces can be examined directly without the necessity for ion-beam milling. For example, coatings of boron nitride prepared from a polymeric precursor have been applied to the surfaces of crystalline oxides such as MgO, Al2O3 and TiO2. The initially amorphous BN wets the crystalline oxide surfaces and crystallizes to form tough, adherent coatings of hexagonal BN. On crystalline specimens, the hexagonal BN grows with the {002} layer planes locally parallel to the oxide surface in each instance, permitting interfaces between the {002} BN layers and particular oxide planes to be studied. The most successful results have been obtained to date from studies of BN on MgO{110} surfaces. The work described here details the characterization of the atomic structure of these model BN/MgO interfaces by methods of high-resolution electron microscopy.
Vapor saturation of sodium: Key to unlocking the origin of chondrules

Abstract Sodium saturation of the vapor coexisting with chondrules at their liquidus temperatures implies that vapor-condensed phase equilibrium was reached at those temperatures for all elements more refractory than sodium. In order to investigate the possibility that chondrules formed in impact-generated plumes, equilibrium calculations were applied to droplets made from two different target compositions. Combinations of dust enrichment and P tot were found that lead to sodium saturation, and the subsequent chemical and mineralogical evolution of the droplets was explored at those conditions. If an impact on a body of CI composition caused instantaneous heating, melting and devolatilization of the target rock and ejection of a plume of gaseous, liquid and solid matter that mixed with residual nebular gas at conditions where 50% or 90% of the sodium was retained by the resulting droplets at their liquidus temperature, their mineralogical and chemical properties would strongly resemble those of Type II chondrules. If the droplets cooled and equilibrated with the mixture of residual nebular gas and their devolatilized water, sulfur and alkalis, the fayalite content of the olivine and the chemical compositions of the bulk droplets and their glasses would closely resemble those of Types IIA and IIAB chondrules at CI dust enrichments between 400× and 800×. For 50% sodium retention, the corresponding values of P tot are 2 bars (for 400×) and 1 bar (for 800×). For 90% retention, they are 25 and 10 bars, respectively. If, instead, the target has an anhydrous, ordinary chondrite-like composition, called H′, the ejected droplets are bathed in a gas mix consisting mostly of devolatilized sulfur and alkalis with residual nebular gas, a much more reducing plume. If the conditions were such that sodium were retained by the resulting droplets at their liquidus temperature, the fayalite contents of the olivine and the chemical compositions of the bulk droplets and their glasses would closely resemble those of Types IA and IAB chondrules at H′ dust enrichments between 10 3 × and 4 × 10 3 ×. For 90% sodium retention, the corresponding values of P tot are 15 bars (for 10 3 ×) and 2 bars (for 4 × 10 3 ×). For 50% retention, they are 2 and 8 × 10 −2 bars, respectively.
Regulations during survival without oxygen in infant mammals.

Abstract Infants of five species: ground squirrel, white rat, golden hamster, cat and dog, were given purified nitrogen to breathe. Colonic temperatures were maintained at 37 °C. Breath frequencies and heart rates suddenly diminished and remained at low levels during the anoxia. Heart beats persisted long after breaths ceased in all instances of non-survival. Recovery usually followed if 1–3 breaths per minute had continued until air became available; ground squirrels survived periods of apnea lasting as long as 18 min. Some deaths occurred even after air had been inhaled. With advancing ages in each species the resistance times to anoxia decreased exponentially. Mean survivals of 10 min were located at postnatal ages from 3 days (hamster) to 16 days (ground squirrel).
Calcium metabolism and active tension in mechanically disaggregated heart muscle.

Abstract We have measured the active tension generated by spontaneously beating fragments of mouse ventricular myocardium prepared by mechanical mincing. Tension oscillations were observed only when the ionized calcium concentration in the medium was more than 10 −7 m and less than 10 −4 m . Sustained relaxation or contraction, respectively, were observed at these concentration limits. In contrast to this sensitivity to calcium, wide variations in Na K had almost no effect on contractility. Lanthanum had no effect at low concentrations, but caused contracture at 10 −3 m . These observations suggest that the sarcolemma of these spontaneously beating fragments is fully permeable to Na + , K + , Ca 2+ , and La 3+ , and that trans-sarcolemmal electrical events are not the determinant of beating. These conclusions were further supported by our failure to detect any significant transmembrane potential with intracellular electrodes, and our inability to pace the fragments by field stimulation. The responses to azide, oligomycin, and caffeine were used to determine the roles of mitochondria and SR in control of tension oscillations. These experiments indicated that while mitochondria may control resting tension, SR function is needed for cyclic contraction and relaxation in these myocardial fragments.
ED50 levels of Penicillium digitatum and P. italicum with reduced sensitivity to thiabendazole, benomyl and imazalil

Abstract The ED 50 values of 415 isolates of Penicillium digitatum Sacc. and P. italicum Wehmer with reduced sensitivity to thiabendazole (TBZ), benomyl (BEN) and/or imazalil (IM) were assessed. The isolates were collected from decayed grapefruit ( Citrus paradisi Macf.), lemons ( C. limon (L.) Burm. f.), mandarins ( C. reticulata Blanco) and oranges ( C. sinensis (L.) Osbeck) from 14 geographical origins. The isolates were cultured on potato dextrose agar containing yeast extract and amended with a series of fungicide concentrations. The mean ED 50 values of P. digitatum were 15.8 mg/L for TBZ, 6.3 mg/L for BEN and 0.88 mg/L for IM. Double-resistant (that is, resistant to both IM and benzimidazole fungicides) isolates were significantly more sensitive to TBZ and/or BEN than isolates resistant to the benzimidazoles only. The mean ED 50 values of P. italicum were 22.6 mg/L for TBZ and 4.7 mg/L for BEN. The resistance levels of green and blue mold to the benzimidazoles were related to their geographical origins.
Laser radiation pressure slowing of a molecular beam.

We demonstrate deceleration of a beam of neutral strontium monofluoride molecules using radiative forces. Under certain conditions, the deceleration results in a substantial flux of detected molecules with velocities $\ensuremath{\lesssim}50\text{ }\text{ }\mathrm{m}/\mathrm{s}$. Simulations and other data indicate that the detection of molecules below this velocity is greatly diminished by transverse divergence from the beam. The observed slowing, from $\ensuremath{\sim}140\text{ }\text{ }\mathrm{m}/\mathrm{s}$, corresponds to scattering $\ensuremath{\gtrsim}{10}^{4}$ photons. We also observe longitudinal velocity compression under different conditions. Combined with molecular laser cooling techniques, this lays the groundwork to create slow and cold molecular beams suitable for trap loading.
Line-associated bloodstream infections in pediatric intensive-care-unit patients associated with a needleless device and intermittent intravenous therapy.

Objectives To determine risk factors for an increase in line-associated bloodstream infections (BSIs) in three pediatric intensive-care units at one hospital that recently had changed brands of needleless access device. Design Retrospective case-control studies; review of the units' infection control policies and procedures for accessing and replacing components of needleless access devices. Setting A community tertiary-care hospital's three pediatric intensive-care units. Patients Children in one of the three intensive-care units with a central venous catheter in place during January 1, 1995, through May 15, 1996, who developed laboratory-confirmed primary BSI. Children who had central venous catheters in place for >48 hours and who did not develop BSI were chosen randomly as controls. Results Eight patients met the case definition; they had 11 episodes of BSI. Multivariate analysis identified duration of catheterization and exposure to the IVAC first-generation needleless device as independent risk factors for BSI. Compared with patients from another pediatric intensive-care unit in which the IVAC device also was used but in which an increased BSI rate did not occur, patients from the unit with an increased BSI rate were more likely to receive intermittent (vs continuous) intravenous therapy through one or more lumens. In both units, the IVAC device valve component was replaced every 6 days, and the endcap used to cover the valve (when connected to an unused lumen) was replaced every 24 hours or after each access. The BSI rate returned to baseline after institution of a policy to replace the entire IVAC device, valve, and endcap every 24 hours. Conclusions An increased risk of BSI was associated with use of the IVAC first-generation needleless device when replaced every 6 days. This increased risk may have been more pronounced in one pediatric intensive-care unit, because patients were more likely to receive intermittent intravenous therapy. Intermittent intravenous therapy or central venous catheter flushing practices may be important determinants of BSI risk.
A case for deliberation in response to hormesis research

Research on the phenomenon of hormesis (i.e., low-dose stimulatory effects caused by normally inhibitory or toxic substances) has recently provoked a good deal of debate. Formal mechanisms for deliberation and public participation are increasingly popular strategies for responding to controversial decisions in environmental policy, but they have been used only to a limited extent in response to scientific research itself. This commentary introduces natural scientists to some of the social scientific literature on these issues and argues for the importance of "diagnosing" whether controversial areas of policy relevant research would benefit from some form of deliberation. It provides a tentative diagnosis in the case of hormesis research, recommending a varied deliberative approach. There are many reasons to pursue broadly based deliberation in response to hormesis, including the potential to promote more productive research projects, alleviate public distrust, and prevent bias. Deliberative proceedings in this case should address judgments associated with at least four activities: (1) choosing projects and designing studies, (2) developing terminology, (3) interpreting and evaluating studies, and (4) applying research results to public policy. Although an advisory group composed primarily of experts might provide an adequate starting point, more intensive deliberative processes would be valuable before developing major changes to regulatory policy.
The effects of conversations with regulars and administrators on the participation of new users in a virtual learning community

We analyze new users' participation rates on MOOSE Crossing, a collaborative educational environment. New MOOSE Crossing users who conversed with regulars or administrators soon after joining are found to exhibit more social activity and stay involved with MOOSE Crossing longer thah new users who did not. We find regulars to be better at eliciting participation than administrators, but also note a synergistic interaction between the groups.
Sexual Intimacy and Drug Use in TV Series

Content analysis shows alcohol as the only drug used more than twice per hour; intimate sex is presented or talked about nearly twice per hour, seldom between married partners.
Remarks on fractal W-gravity

We discuss the quantum field theory of extended two-dimensional gravity associated with Zamolodchikov's W -algebra. By using some ansalze on the geometry, we argue that it is described by the appropriate affine Lie algebra when we pick the light-cone gauge fixing, which generalizes the result of Knizhnik, Polyakoff and Zamolodchikov.
Plasmonic interactions between a metallic nanoshell and a thin metallic film

The plasmonic interaction and optical properties of a metallic nanoshell near a metallic film are investigated theoretically and experimentally. The plasmon hybridization method is extended to include the screening effects mediated by dielectric backgrounds and a realistic description of the dielectric properties of the metal. We show that the plasmonic structure of the system depends strongly on the aspect ratio of the nanoshell (the ratio of inner to outer radius) and the thickness of the film. In the thin film limit, the plasmonic coupling between the nanoshell and the film induces a low-energy virtual state (VS) mainly consisting of delocalized thin film plasmons. We show that the energy and intensity of this state can both be controlled by the aspect ratio of the nanoshell and the thickness of the film. The theoretical results are found to agree well with experimental observations. Using finite-difference time-domain simulations, we show that the electromagnetic field enhancements induced by excitation of the VS can be very large and that the nanoshell/thin film system could serve as a tunable plasmonic substrate for surface enhanced spectroscopies.
Reactivity of tryptophans in rhodopsin

Abstract Oxidation with N-bromosuccinimide detects a total of about ten tryptophan residues in detergent-solubilized bovine rhodopsin. One of these tryptophans is more reactive in bleached than in unbleached rhodopsin, suggesting its involvement in the chromophore binding site. Oxidation of this residue is accompanied by loss of the 500nm. absorbance in unbleached rhodopsin. Similar experiments with bacteriorhodopsin are inconclusive.
Introduction to Organizational and Social Dynamics in Information Technology Minitrack

This track addresses social issues related to information technology. Social issues are those research topics most aligned with the human factor in terms of information systems planning, development and utilization. The minitrack contains the following paper topic areas and addresses key topic areas related to (1) trust, (2) relationships, (3) human interaction, (4) diversity and culture in the IT workforce, among other social and IT issues.
Eliminating transient artifacts in stabilized-image contrast thresholds.

In the measurement of contrast thresholds for stationary, stabilized images, the choice of the psychophysical procedure may profoundly affect the results by constraining the time course of the stimulus presentation. With some procedures, the subject is unable to ignore transients; as a result, he necessarily responds to onset and offset transients rather than to the intended stimulus. Here we report significant effects of (a) the rapidity of onset and (b) the duration of the stimulus on thresholds for stabilized sinusoidal-grating patterns; these effects occur with both forced-choice and standard yes/no procedures. No value of either parameter (a) or (b) can eliminate such presentation effects when these procedures are used. However, we have devised a new, continuous-presentation procedure that yields results that do not depend on these parameters. Contrast thresholds for stabilized and for unstabilized stimuli measured by this procedure differ by 1 log unit or more, in good agreement with the results obtained by careful use of the method of adjustment.
Middle Triassic megafossil plants from Long Gully, near Otematata, north Otago, New Zealand

Abstract The Long Gully Formation of the Corbies Creek Group contains abundant remains of the low-diversity coastal vegetation characteristic of the Middle and Late Triassic Pacific margins of Gondwana. The plant-bearing rocks in Long Gully conformably overlie fossiliferous deltaic and marine Ladinian rocks (Kaihikuan local stage). A variety of fossil fructifications were found, allowing better understanding of the botanical affinities of the plants. Fertile remains referred to Todites maoricus sp. nov., indicate osmundalean affinities for one common kind of sphenopterid fern frond. Townrovia petasata gen. et sp. nov. is the likely microsporophyll and ? Peltaspermum sp. indet. the likely megasporophyll of seed fern leaves referred to Pachydermophyllum, represented at Long Gully by P. dubium (Burges) comb. nov. and P. praecordillerae (Frenguelli) comb. nov. The ovulate voltziacean conifer cone Telemachus lignosus sp. nov. and “unidentified cone B” may be fructifications of a species also producing leaves r...
The Genesis of Severe, Long-Lived Bow Echoes

Abstract A series of idealized simulations using a nonhydrostatic cloud model is used to investigate the genesis of bow echoes (a bow-shaped system of convective cells that is especially noted for producing long swaths of damaging surface winds). It is hypothesized that severe, long-lived bow echoes represent a dynamically unique form of mesoconvective organization being produced for a restricted range of environmental conditions, including a convective available potential energy (CAPE) of at least 2000 m2 s2 and vertical wind shears of at least 20 m s−1 over the lowest 2.5–5 km AGL. The key structural features include a 40–100-km-long bow-shaped segment of convective cells, with a strong rear-inflow jet extending to the leading edge of the bow at 2–3 km AGL, and cyclonic and anticyclonic eddies (referred to as “bookend” vortices) on the northern and southern flanks of the bowed segment, respectively. This structure characteristically develops three to four hours into the lifetime of a convective system a...
Suppression of Ribosomal Function Triggers Innate Immune Signaling through Activation of the NLRP3 Inflammasome

Some inflammatory stimuli trigger activation of the NLRP3 inflammasome by inducing efflux of cellular potassium. Loss of cellular potassium is known to potently suppress protein synthesis, leading us to test whether the inhibition of protein synthesis itself serves as an activating signal for the NLRP3 inflammasome. Murine bone marrow-derived macrophages, either primed by LPS or unprimed, were exposed to a panel of inhibitors of ribosomal function: ricin, cycloheximide, puromycin, pactamycin, and anisomycin. Macrophages were also exposed to nigericin, ATP, monosodium urate (MSU), and poly I:C. Synthesis of pro-IL-s and release of IL-1s from cells in response to these agents was detected by immunoblotting and ELISA. Release of intracellular potassium was measured by mass spectrometry. Inhibition of translation by each of the tested translation inhibitors led to processing of IL-1s, which was released from cells. Processing and release of IL-1s was reduced or absent from cells deficient in NLRP3, ASC, or caspase-1, demonstrating the role of the NLRP3 inflammasome. Despite the inability of these inhibitors to trigger efflux of intracellular potassium, the addition of high extracellular potassium suppressed activation of the NLRP3 inflammasome. MSU and double-stranded RNA, which are known to activate the NLRP3 inflammasome, also substantially inhibited protein translation, supporting a close association between inhibition of translation and inflammasome activation. These data demonstrate that translational inhibition itself constitutes a heretofore-unrecognized mechanism underlying IL-1s dependent inflammatory signaling and that other physical, chemical, or pathogen-associated agents that impair translation may lead to IL-1s-dependent inflammation through activation of the NLRP3 inflammasome. For agents that inhibit translation through decreased cellular potassium, the application of high extracellular potassium restores protein translation and suppresses activation of the NLRP inflammasome. For agents that inhibit translation through mechanisms that do not involve loss of potassium, high extracellular potassium suppresses IL-1s processing through a mechanism that remains undefined.
Digital Testimonio As a Signature Pedagogy for Latin@ Studies

This article proposes the curricular integration of digital testimonio as a “signature” pedagogy in Latin@ Studies. The testimonio tradition of urgent narratives and the creative multimedia languages of digital storytelling—text, voice, image, and sound—invite historically marginalized subjects, especially younger generations, to author and inscribe their own social and cultural truths. Taking inspiration from Latina writings, undergraduate students script, record, produce, publish, and theorize their own testimonios, building new knowledge from personal and collective experience. In this process, they construct historical and theoretical understandings of identity and belonging, reproducing and reinforcing the testimonial nexus between individual and collective story. For cyberspace generations, the digital multimedia format facilitates coming to voice. The claim for “signature” pedagogy is based on my 10-year experience with the digital storytelling genre, facilitating the creation of approximately 300 ...
A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years.

Abstract Jackson AB, Dijkers M, DeVivo M, Poczatek RB. A demographic profile of new traumatic spinal cord injuries: change and stability over 30 years. Arch Phys Med Rehabil 2004; 85:1740-8. Objective To evaluate epidemiologic trends in new spinal cord injuries (SCIs) in the United States over 3 decades. Design Consecutive case series. Setting Model Spinal Cord Injury Systems (MSCIS) facilities. Participants Persons (N=30,532) admitted to MSCIS facilities within 365 days of injury between 1973 and 2003, and enrolled in the National Spinal Cord Injury Database. Interventions Not applicable. Main outcome measures Data were collected at MSCIS admission and rehabilitation discharge. Variables included age, gender, race and ethnic group, year of injury, and level and extent of injury. Specific etiologies were grouped as motor vehicle collisions (MVCs), violence, falls, sports, and other. Demographic and injury severity trends were analyzed by year of injury groupings according to decades (1973–1979, 1980–1989, 1990–1999, 2000–2003.) Chi-square tests assessed statistical significance. One-way analysis of variance compared mean ages. Results The male/female ratio remained fairly stable at 4:1, but the percentage of women increased slightly over time, especially from MVC etiologies ( P P Conclusions Many previously seen SCI demographic trends continued into the 2000 decade.
EMBRYOLOGY AND DEVELOPMENT OF THE ENDOSPERM HAUSTORIUM OF ARCEUTHOBIUM DOUGLASII

A B S T R A-C T Arceuthobium douglasii develops a dome-like structure, the ovarian papilla, in which 2 megasporocytes are formed. The papilla is not a true ovule, for no integuments are formed, and it is forced aside by the developing endosperm. Megasporocytes are differentiated in the spring, but meiosis does not occur until the following spring. A tetrasporic embryo sac is developed which is 8-nucleate at maturity. Pollination and fertilization occur approximately 13-14 months after initiation of the inflorescence. Only 1 of the 2 embryos develops after fertilization. After fertilization, the embryo sac segregates into 2 parts, one containing the zygote and the disintegrating synergids, the other the primary endosperm nucleus and the degenerating antipodals. This primary endosperm cell elongates toward the base of the ovarian papilla. Cytokinesis then forms an endosperm cell, adjacent to the zygote, and a haustorial cell. The haustorial cell forms several tiers of cells which persist during the development of the embryo and endosperm. The zygote, while still contained within the ovarian papilla, divides, forming a 2-celled sphere. It remains unchanged until after it is conveyed out of the ovarian papilla by the developing endosperm. The development of the embryo and endosperm is arrested in the autumn approximately 3 months after their initiation. They complete their development the following spring and summer. iVIOS'T previous developmental studies in the genus Arceuthobium have dealt with the endophytic system (Thoday and Johnson, 1930) and with the mature fruit. A few papers have been published which cover various aspects of megasporogenesis, embryology, and endosperm development in different species of Arceuthobium (Johnson, 1888; Thoday and Johnson, 1930; Dowding, 1931; and Cohen, 1963). Because these investigations are not entirely in agreement with one another and because some stages of embryology have not been presented, there is need for further morphological study on several species of the genus. The present paper presents only part of the ontogeny of 1 species (A. douglasii), namely, development of the megasporocyte and the embryo sac, fertilization, and early embryonic and endospermic development. MATERIALS AND METHODS-Staminate and pis
Exact finite difference and non-standard finite difference schemes for

Exact finite difference schemes and non-standard finite difference schemes are constructed for the first-order differential equation , for and . In particular, we show that the central finite difference scheme is an exact scheme for the differential equation .
Structure of vector mesons in a holographic model with linear confinement

Wave functions and form factors of vector mesons are investigated in the holographic dual model of quantum chromodynamics with oscillator-like infrared cutoff. We introduce wave functions conjugate to solutions of the 5D equation of motion and develop a formalism based on these wave functions, which are very similar to those of a quantum-mechanical oscillator. For the lowest bound state ($\ensuremath{\rho}$-meson), we show that, in this model, the basic elastic form factor exhibits the perfect vector meson dominance, i.e., it is given by the $\ensuremath{\rho}$-pole contribution alone. The electric radius of the $\ensuremath{\rho}$-meson is calculated, $⟨{r}_{\ensuremath{\rho}}^{2}{⟩}_{C}=0.655\text{ }\text{ }{\mathrm{fm}}^{2}$, which is larger than in the case of the hard-wall cutoff. The squared radii of higher excited states are found to increase logarithmically rather than linearly with the radial excitation number. We calculate the coupling constant ${f}_{\ensuremath{\rho}}$ and find that the experimental value is closer to that calculated in the hard-wall model.
An electronically-collimated portable gamma-ray detector for locating environmental radiation sources

We are developing a detector system for locating environmental radiation sources. The design emphasizes compact size (ideally hand-held), wide field of view and high detection efficiency, and uses cadmium-zinc-telluride (CZT) detectors and electronic collimation via Compton-scatter detection. The detector design is a 6-sided box with a primary scatter detector on one end. GEANT4 simulations, allowing variations of detector parameters and source energies/locations, provided performance estimates. A partial prototype, using 16×16-pixel 38×38×5-mm 3 CZT detectors, was developed and tested. Two methods to calculate source direction in real-time from the Compton scatter data were evaluated: (1) filtered backprojection of cones onto a sphere; (2) intersection with the sphere of bounding boxes circumscribed around the cones. Simulation results of the 6-sided box with the current CZT modules indicated 1-5% of incident gamma rays produce valid direction angles, with an angular resolution of ∼15°. The directional algorithms allowed a FOV (directional error <10°) of approximately ±60°. The direction algorithms converge on a source direction estimate in as few as 100 detected events. With improvements in detector energy and spatial resolution, reasonable performance seems achievable for a range of radioisotopes, e.g., from Am-241 through Co-60.
Objective Behavior Associated With an “Ordinary” Mild Headache: A Surprising Failure of Pain Onset to Signal Self-protective or Self-regulatory Behavior

Objective.—The goal of this study was to determine whether onset of an “ordinary” headache initiated self-protective behavior or self-regulation, as indexed by a reduction in effort expenditure. Methods.—A nonclinical sample was employed. The ambition and performance accuracy of a headache-developing group (n=23) and a sex-matched, headache-free group (n=23) was compared during a series of mental arithmetic problems. Embedded within the series of math problems was a task involving recall of a stressor previously found to induce headache in many subjects. Results.—Onset of mild head pain did not lead to effort conservation; instead, heightened ambition appeared to characterize the headache-developing participants before as well as after headache onset. Headache-developing subjects also displayed a performance accuracy deficit. Conclusions.—The data suggest unusually ambitious, effortful task engagement may contribute to the onset of mild “ordinary” headache. This possibility requires further examination under other controlled conditions as well as in the natural environment.
Carbohydrate reserves and infectivity in Trichinella spiralis isolated from carrion.

Trichinous mice were killed and their carcasses maintained at room temperature or subzero temperatures for varying lengths of time. Some worm parameters were measured after direct isolation from carcasses while others were measured following passage through a second round of hosts. Glycogen and trehalose levels in infective 1st-stage larvae (L1) isolated directly from carcasses maintained at room temperature were significantly less than controls (day 0) after day 4 post-kill (p.k.). By day 21 p.k. among L1 isolated directly from mouse carcasses those observed coiled or moving had decreased by around 20% compared to day 0 p.k. The percentage of L1 isolated from carcasses on several days p.k., used to infect mice and recovered as pre-adult worms declined significantly after they had remained in carcasses for 14 days. Only 2.6% of muscle larvae isolated from carcasses on day 21 p.k. and used to infect mice were recoverable as pre-adults. Pre-adult worms raised in mice infected with larvae from day 7 carcasses had about 50% less glycogen than worms raised in mice infected with larvae isolated from fresh carcasses (day 0 p.k.). The fecundity in vitro of adult worms isolated from mice on day 7 following infection with infective L1 larvae maintained in carcasses held at room temperature for 0-16 days declined only when adult worms developed from larvae recovered from carcasses at 3 days following host death. Following 24 h at temperatures below freezing, infectivity of L1 larvae isolated from frozen carcasses was reduced by 97%. Carbohydrate levels remained high in larvae from carcasses frozen for up to 4 days.
Acoustic emissions from rapidly moving cracks.

Linear elasticity is unable to predict completely the dynamics of a rapidly moving crack without the addition of a phenomenological fracture energy. Our measurements of acoustic emission, crack velocity, and surface structure demonstrate quantitatively similar dynamical fracture behavior in two very different materials, polymethylmethacrylate and soda-lime glass. This unexpected agreement suggests that there exist universal features of the fracture energy that result from dissipation of energy in a dynamical instability.
Fully Integrated Capacitive DC–DC Converter With All-Digital Ripple Mitigation Technique

This paper presents an adaptive all-digital ripple mitigation technique for fully integrated capacitive dc-dc converters. Ripple control is achieved using a two-pronged approach where coarse ripple control is achieved by varying the size of the bucket capacitance, and fine control is achieved by charge/discharge time modulation of the bucket capacitors used to transfer the charge between the input and output, both of which are completely digital techniques. A dual-loop control was used to achieve regulation and ripple control. The primary single-bound hysteretic control loop achieves voltage regulation and the secondary loop is responsible for ripple control. The dual-loop control modulates the charge/discharge pulse width in a hysteretic variable-frequency environment using a simple digital pulse width modulator. The fully integrated converter was implemented in IBM's 130-nm CMOS process. Ripple reduces from 98 to 30 mV, when ripple control secondary loop is enabled for a load of 0.3 V and 4 mA without significantly impacting the converter's core efficiency. Measurement results show constant ripple, independent of output voltage. The converter achieves a maximum efficiency of 70% for Vin= 1.3 V and Vout= 0.5 V and a maximum power density of 24.5 mW/mm2, including the areas for the decoupling capacitor. The maximum power density increases to 68 mW/mm2 if the decoupling capacitor is assumed to be already present as part of the digital design.
A TEST OF RENAL FUNCTION: EXCRETION OF CONTRAST MEDIUM AS MEASURED BY URINARY SPECIFIC GRAVITY

SUMMARY 1The excretion of a contrast medium, measured by specific gravity of the urine, appears to be a valid measure of renal function, as indicated by a close correlation with both PSP excretion and levels of serum creatinine. 2The maximal ability of the kidneys to excrete the contrast medium is determined by the increase in specific gravity over that of a pre-injection baseline specimen. 3With the dosage of contrast medium commonly used for excretory urography, the specific gravity of the urine increases rapidly, persisting at an elevated level for up to two hours. Accurate timing for collection of specimens is, therefore, unnecessary. 4Since the increase in urinary specific gravity is a measure of the concentration of excreted contrast medium, determinations of volume are unnecessary. 5An increase in specific gravity of 0.025 unit or greater indicates normal renal function. 6The test is a most useful adjunct to excretory urography, particularly in cases of poor opacification. 7The test is accurate, inexpensive, and simply performed.
Critical Family History, Identity, and Historical Memory

Many teacher educators recommend that preservice teachers examine their own backgrounds and experiences to identify assumptions, beliefs, and values, as well as cultural contexts in which they grew...
Crystal structures of Escherichia coli exonuclease I in complex with single-stranded DNA provide insights into the mechanism of processive digestion

Escherichia coli Exonuclease I (ExoI) digests single-stranded DNA (ssDNA) in the 3′-5′ direction in a highly processive manner. The crystal structure of ExoI, determined previously in the absence of DNA, revealed a C-shaped molecule with three domains that form a central positively charged groove. The active site is at the bottom of the groove, while an extended loop, proposed to encircle the DNA, crosses over the groove. Here, we present crystal structures of ExoI in complex with four different ssDNA substrates. The structures all have the ssDNA bound in essentially the predicted manner, with the 3′-end in the active site and the downstream end under the crossover loop. The central nucleotides of the DNA form a prominent bulge that contacts the SH3-like domain, while the nucleotides at the downstream end of the DNA form extensive interactions with an ‘anchor’ site. Seven of the complexes are similar to one another, but one has the ssDNA bound in a distinct conformation. The highest-resolution structure, determined at 1.95 A, reveals an Mg2+ ion bound to the scissile phosphate in a position corresponding to MgB in related two-metal nucleases. The structures provide new insights into the mechanism of processive digestion that will be discussed.
The Yin and Yang of microRNAs: leukemia and immunity

Yin and Yang are two complementary forces that together describe the nature of real-world elements. Yin is the dark side; Yang is the light side. We describe microRNAs having both Yin and Yang characteristics because they can contribute to normal function (Yang) but also to autoimmunity, myeloproliferation, and cancer (Yin). We have been working on a number of microRNAs that have these dual characteristics and here we focus on two, miR-125b and miR-146a. We have concentrated on these two RNAs because we have very extensive knowledge of them, much of it from our laboratory, and also because they provide a strong contrast: the effects of overexpression of miR-125b are rapid, suggesting that it acts directly, whereas the effects of miR-146a are slow to develop, suggesting that they arise from chronic alterations in cellular behavior.
Anaerobic metabolism enzymes as markers of flooding stress in maize seeds

Maize (Zea mays L.) seeds differ in their relative tolerance to the anaerobic environment caused by flooding. Seed tolerance to flooding stress depends on cellular and metabolic processes since gross anatomical responses have not developed at the pre-emergence stage. The study reported here characterizes the activities of four anaerobic respiratory enzymes: pyruvate decarboxylase (PDC), alcohol dehydrogenase (ADH), lactate dehydrogenase (LDH), and malic enzyme (ME) in the flood-tolerant A632 and floodsusceptible Mo 17 inbred maize seeds during flooding at 10 and 25°C. Each inbred consisted of two seed lots possessing 95% and 75% germination levels. Flooding increased the activities of all four enzymes. However, no consistent correlation between anaerobic enzyme activity and flood tolerance was observed across genotype, seed quality and flooding temperature. The results indicate that it may not be feasible to use whole-seed anaerobic enzyme activities to predict maize seed performance under flooding stress.
Vibrational energy transfer in fluids

Abstract A review of several of the available theories of vibrational energy transfer (VET) in the gas and liquid phases is presented. First the classical theory of gas phase VET mainly due to Landau and Teller, to Jackson and Mott and to Zener is developed in some detail. Next the Schwartz-Slawsky-Herzfeld theory, a framework for analysing VET data based on the classical theory, is outlined. Experimental tests of the classical theory and theoretical critiques of its assumptions are then described. Next a brief review of the modern ab-initio quantum approach to gas phase VET rates, taking as an example the work of Banks, Clary and Werner, is given. Theories of VET at elevated densities are then discussed. The isolated binary collision model is reviewed and a new molecular approach to the density, temperature and isotope dependences of vibrational energy relaxation rates, due to Adelman and co-workers, is outlined.
Delineating the Multifunctional Role of Agroecological Practices: Toward Sustainable Livelihoods for Smallholder Farmers in Developing Countries

Agroecological practices have increasingly been recognized as major development alternatives that could ensure rural people's basic needs while enhancing the ecological capacities grounding their livelihoods. This paper explores the multifaceted dimensions of agroecological practices that could potentially address the compelling livelihood necessities of less advantaged smallholder farmers in developing countries. It is argued that, despite its claim to uphold interdisciplinary approaches, agroecology as a scientific discipline has originally been led by ecologists and agronomists, with interdisciplinary collaboration largely limited to anthropologists. The concept of agricultural multifunctionality is proposed to help address the existing limitations in agroecology and thus overcome the conventional chasm between ecological research and social realities in agroecology-based development.
Bidirectional Relationships and Attractor Structure of Boolean Networks

Inferring Boolean networks from non-temporal data suffers from a lack of directionality of the prediction. As a result, inferred networks often possess spurious non-singleton attractor cycles inconsistent with the assumption that the data represent the steady-state of the real genomic regulatory system. Bidirectional gene relationships can be responsible for non-singleton attractor cycles and thereby adversely affect network design. We present several results relating bidirectional gene relationships to attractor cycles.
Probability-density function model of turbulent hydrogen flames⋆

Abstract Hydrogen combustion attracted much attention recently because of the need for clean alternative energy. For the theoretical/numerical study of hydrogen combustion, there is a need for modeling capabilities for turbulent hydrogen flames. The present work examines the applicability of probability density function (pdf) turbulence models. For the purpose of accurate prediction of turbulent combustion, an algorithm that combines a conventional CFD flow solver with the Monte Carlo simulation of the pdf evolution equation, has been developed. The algorithm is validated using experimental data for a heated turbulent plane jet. A study of H2–F2 diffusion flames has been carried out using this algorithm. Numerical results show that the pdf method is capable of correctly simulating turbulence effects in hydrogen combustion.
Predicting Blood Glucose Levels Around Meals for Patients With Type I Diabetes

Insulin pumps and continuous glucose monitors enable automatic control of blood glucose (BG) levels for patients with type 1 diabetes. Such controllers should carefully assess the likely future BG levels before injecting insulin, since the effects of insulin are prolonged, potentially deadly, and irreversible. Meals pose a strong challenge to this assessment as they create large, fast disturbances. Fortunately, meals have consistent and predictable effects, if their size and start time are known. We present a predictive algorithm that embeds meal detection and estimation into BG prediction. It uses a multiple hypothesis fault detector to identify meal occurrences, and linear Kalman filters to estimate meal sizes. It extrapolates and combines the state and state covariance estimates to form a prediction of BG values and uncertainties. These inputs enable controllers to assess and trade off the acute risks of low and chronic risks of high BG levels. We evaluate the predictor on simulated and clinical data.Copyright © 2010 by ASME
Changes in barometric pressure and ambient temperature influence osteoarthritis pain.

Abstract Purpose Individuals with osteoarthritis often assert that change in the weather influences their pain, but the evidence is inconclusive. Our objective was to determine if short-term weather parameters influence knee osteoarthritis pain. Methods We performed a longitudinal analysis of pain reports from a 3-month clinical trial among individuals with knee osteoarthritis dispersed across the United States. Daily values for temperature, barometric pressure, dew point, precipitation, and relative humidity were obtained from the weather station closest to each participant. We used a longitudinal mixed-model random effects analysis with a first-order autoregressive error structure to test for associations while accounting for within-patient correlation. Results The study included 200 participants with knee osteoarthritis. Their mean age was 60 years (standard deviation [SD] 9.4), 64% were female, and 10.5% were African American or Hispanic. They had a mean body mass index of 32.5 kg/m 2 (SD 8.4) and a baseline WOMAC pain score of 9.0 (SD 3.4). There were consistent associations of pressure change and ambient temperature with pain severity (change in barometric pressure, coefficient=1.14, P = .02, ambient temperature=−0.01, P = .004; adjusted mutually and for age, gender, body mass index, nonsteroidal anti-inflammatory drug use, opiate use, and prior pain score). Interaction terms between change in barometric pressure and ambient temperature had no influence in the models. Conclusions Changes in barometric pressure and ambient temperature are independently associated with osteoarthritis knee pain severity.
Chekhov and Rossolimo Careers in medicine and neurology in Russia 100 years ago

Neurology as a specialty was established at the close of the 19th century, especially in England, France, Germany, and the United States. It was not uncommon for US physicians to seek postgraduate training in those three Western European countries. However, Russian clinical investigators and scientists, who contributed to neurology and the neurosciences, rarely had their papers cited in Western medical publications. The medical careers of the well-known writer-physician Anton P. Chekhov and his contemporary G.I. Rossolimo, an academic neurologist at the University of Moscow, illustrate their contributions within the constraints of their autocratic society. Their work led to a better understanding of the complexities of human behavior, Chekhov through his enduring writings, and Rossolimo as a founder of neuropsychology and child neurology.
Why modules matter.

The serendipitous discovery of the SH2 domain unleashed a sea-change in our conceptual molecular understanding of protein function. The reductionist approaches that followed from the recognition of modular protein interaction domains transformed our understanding of cellular signal transduction systems, how they evolve and how they may be manipulated. We now recognize thousands of conserved protein modules – many of which have been described in structure and function, implicated in disease, or underlie targeted therapeutics. The reductionist study of isolated protein modules has enabled the reconstruction of the protein interaction networks that underlie cellular signalling. Protein modules themselves are becoming tools to probe cellular activation states and identify key interactions hubs in both normal and diseased cells and the concept of protein modularity is central to the field of synthetic biology. This brief word of introduction serves to highlight the historical impact of the very powerful idea of protein modules and sets the stage for the exciting on-going discoveries discussed in this issue.