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The COVID-19 pandemic has given rise to many significant research activities, among these a resurgence of the use of control-oriented approaches for modeling and controlling epidemics. An examination of a SIR (Susceptible-Infectious-Recovered) dynamic model under endemic conditions using Internal Model Control (IMC) shows that a two-degree-of-freedom (2DoF) PID with filter structure is a natural solution for understanding how to manage a pandemic, with model-based IMC-PID tuning being extremely effective when evaluated on a first-principles, nonlinear plant model. Dynamic modeling (nonlinear and linearized), PID controller design, and closed-loop evaluation (under conditions that include vaccination and the loss of immunity/potential for re-infection) are presented, with the results demonstrating the deep insights that can be gained from simple models and control policies. Computational models as presented in this work could be used to inform the actions of governments and individuals.

Three-dimensional photon correlation spectroscopy (3D PCS) is a well-known technique developed to suppress multiple scattering contributions in correlation functions, which are inevitably involved when an optical laser is employed to investigate dynamics in a turbid system. Here, we demonstrate a proof-of-principle study of 3D PCS in the hard X-ray regime. We employ an X-ray optical cross-correlator to measure the dynamics of silica colloidal nanoparticles dispersed in polypropylene glycol. The obtained cross correlation functions show very good agreement with auto-correlation measurements. This demonstration provides the foundation for X-ray speckle-based studies of very densely packed soft matter systems.

Gerechtigkeitserleben spielt eine zentrale Rolle für produktives Wohlbefinden in der Schule und trägt zum Zugehörigkeitsgefühl bei. Die vorliegende Studie untersucht in einem experimentellen Design, wie die Berücksichtigung sonderpädagogischer Förderbedarfe im Sinne des Bedarfsprinzips Gerechtigkeitsbeurteilungen von SchülerInnen-Lehrkraft-Interaktionen beeinflusst. Eine Stichprobe von 275 Lehramtsstudierenden gab an, wie gerecht sie die in Textvignetten beschriebenen Unterrichtssituationen beurteilte. Es zeigte sich ein bedeutsamer Einfluss des Vorhandenseins sonderpädagogischer Förderbedarfe im „Förderschwerpunkt emotionale-soziale Entwicklung“ sowie ein signifikanter Einfluss aus der Kombination von Förderbedarfen im Bereich „Lernen“ und des gerechtigkeitstheoretischen Fokus’ der Vignetten (Verteilungsfragen oder zwischenmenschliche Gerechtigkeitsfragen). Eine Nichtbeachtung des Bedarfsprinzips in inklusiven Unterrichtssituationen führte tendenziell zu einer weniger gerechten Unterrichtswahrnehmung. Eine zusätzliche Information über eine explizite Diagnose beeinflusste die Gerechtigkeitsurteile der Befragten nicht. Die Ergebnisse weisen darauf hin, dass das Bedarfsprinzip in der Beurteilung schulischer Interaktionen bereits bei Lehramtsstudierenden eine Rolle spielt.

Direct 2D spatial-coherence measurements are increasingly gaining importance at synchrotron beamlines, especially due to present and future upgrades of synchrotron facilities to diffraction-limited storage rings. We present a method to determine the 2D spatial coherence of synchrotron radiation in a direct and particularly simple way by using the Fourier-analysis method in conjunction with curved gratings. Direct photon-beam monitoring provided by a curved grating circumvents the otherwise necessary separate determination of the illuminating intensity distribution required for the Fourier-analysis method. Hence, combining these two methods allows for time-resolved spatial-coherence measurements. As a consequence, spatial-coherence degradation effects caused by beamline optics vibrations, which is one of the key issues of state-of-the-art X-ray imaging and scattering beamlines, can be identified and analyzed.

Landscapes on either side of the martian topographic dichotomy bear distinct soil chemistry, but the processes associated with this distinction remain poorly understood. Here, correlation of soil chemistry at global to regional scales is examined with multivariate analysis of Gamma‐Ray Spectrometer chemical maps and the Thermal Emission Spectrometer‐derived Dust Cover Index (DCI). In the analysis, the northern lowlands show a strong S‐Cl correlation, contrasting with the southern highlands, which show a stronger S‐H2O correlation. These observations suggest aqueous interaction with soils throughout the southern highlands, preferentially dissolving Cl compounds and weakening S‐Cl correlation. Strong S‐Cl correlations in the northern lowlands suggest less interaction with aqueous H2O. Additionally, regional analyses demonstrate that DCI does not correlate with volatile chemistry at smaller scales and that Ca may be an important component of volatile‐bearing material. These results provide new evidence for widespread aqueous interaction and possibly alteration of soil in the southern highlands. Mars can be divided into two large regions: the northern lowlands and southern highlands, separated by a planet‐circling change in elevation known as the topographic dichotomy. The soils that cover the landscape in these two areas appear distinct from one another, although it is unclear what processes cause this distinction. This investigation examines the chemistry of soils on either side of the dichotomy based on Gamma‐Ray Spectrometer data, to elucidate changes in soils. The identified changes in correlation of three soil components, sulfur, chlorine, and H2O, suggest that much of the southern highlands soils have interacted with water, but fluid interaction occurred far less in the northern lowlands. These findings show that the processes by which water interacts with soils were likely active over larger areas in the southern highlands than previously realized, but such processes were not active after the northern lowlands soils were deposited. Study represents first multivariate analysis of global martian soil chemistryChemical trends suggest widespread aqueous interaction with soil in the southern highlands and less interaction in, or transport of altered soils to, the northern lowlandsFindings give evidence for potentially widespread altered soils in southern highlands

The Long Valley volcanic region, eastern California, has been characterized by recurrent and generally explosive eruptions in the past 180,000 years, originating from a N/S elongated area ~50 km in extent, including the Mammoth Mountain lava dome complex, the Mono‐Inyo volcanic chain, and their peripheries. Several temporal clusters of activity have been observed in a relatively well‐preserved time‐stratigraphic record, which is nevertheless affected by uncertainties. This study has two main objectives: (1) to fully describe the past eruption record by using a stochastic model capable of combining radiometric ages and stratigraphic constraints and, (2) based on the uncertainty assessment, to develop a doubly stochastic, long‐term temporal model based on the current situation. Multiple approaches are described and compared, and multimodel forecasts are also presented. Our findings provide fundamental information for hazard assessment and forecasting of the next eruption in the Long Valley volcanic region, of which the mean probability of occurrence is estimated to be ~2.5% in the next 10 years and ~22.5% in the next 100 years. There is approximately 22.5% chance of a new volcanic eruption in the Long Valley volcanic region sometime during the next 100 yearsThis estimate has a confidence interval of [18.8%, 27.8%] due to uncertainty in the timing of past eruptions and in the statistical modelWe show that detailed understanding of volcano stratigraphy is required to model the episodic nature of eruptive activity in this area

Craters of the Moon National Monument and Preserve (CotM) is a strong terrestrial analog for lava tube formations on Mars. The commonality of its basalt composition to Martian lava tubes makes it especially useful for probing how interactions between water, rock, and life have developed over time, and what traces of these microbial communities may be detectable by current flight‐capable instrumentation. Our investigations found that secondary mineral deposits within these caves contain a range of underlying compositions that support diverse and active microbial communities. Examining the taxonomy, activity, and metabolic potential of these communities revealed largely heterotrophic life strategies supported by contributions from chemolithoautotrophs that facilitate key elemental cycles. Finally, traces of these microbial communities were detectable by flight‐capable pyrolysis and wet chemistry gas chromatography‐mass spectrometry methods comparable to those employed by the Sample Analysis at Mars (SAM) instrument aboard the Curiosity rover and the Mars Organic Molecule Analyzer (MOMA) on the upcoming Rosalind Franklin rover. Using a suite of methods for chemical derivatization of organic compounds is beneficial for resolving the greatest variety of biosignatures. Tetramethylammonium hydroxide (TMAH), for example, allowed for optimal resolution of long chain fatty acids. Taken together, these results have implications for the direction of mass spectrometry as a tool for biosignature detection on Mars, as well as informing the selection of sampling sites that could potentially host biosignatures. We investigated lava tubes at Craters of the Moon National Monument and Preserve for their potential to host and preserve evidence of life. Lava tubes are found on both Earth and Mars, and can shield life from extreme environmental conditions such as radiation and temperature fluctuation. We found a variety of mineral deposits on the walls of lava tube caves formed by water‐rock interactions throughout time, which hosted diverse microbial communities. These communities contained the ability to generate energy from both inorganic and organic carbon sources, as well as cycle important nutrients such as nitrogen and sulfur. In addition, we used techniques comparable to those employed aboard the Sample Analysis at Mars instrument on the Curiosity rover to understand whether this life could hypothetically be detected by exploratory missions. Many organic molecules were detected using our techniques, demonstrating that these habitats have the potential to preserve life and its traces on other worlds. Genomic results reveal a diverse microbial ecosystem in the lava tubes at Craters of the MoonThere are multiple ways for chemolithotrophic life to harvest energy in this basaltic Mars analog environmentBiosignatures, or traces of life, can be detected in secondary mineral deposits using flight‐like techniques Genomic results reveal a diverse microbial ecosystem in the lava tubes at Craters of the Moon There are multiple ways for chemolithotrophic life to harvest energy in this basaltic Mars analog environment Biosignatures, or traces of life, can be detected in secondary mineral deposits using flight‐like techniques

Measuring basal melting of ice shelves is challenging and represents a critical component toward understanding ocean‐ice interactions and climate change. In November 2011, moorings containing fiber‐optic cables for distributed temperature sensing (DTS) were installed through the McMurdo Ice Shelf, Antarctica, (~200 m) and extending ~600 m into the ice shelf cavity. The high spatial resolution of DTS allows for transient monitoring of the thermal gradient within the ice shelf. The gradient near the ice‐ocean interface is extrapolated to the in situ freezing temperature in order to continuously track the ice‐ocean interface. Seasonal melt rates are calculated to be ~1.0 mm d−1and 8.6 mm d−1, and maximum melting corresponds to the arrival of seasonal warm surface water in the ice shelf cavity between January and April. The development of continuous, surface‐based techniques for measuring basal melting represents a significant advance in monitoring ice shelf stability and ice‐ocean interactions. Antarctic fiber‐optic moorings for distributed temperature sensingObservations of basal melting at the ice‐ocean interfaceMeasurement of seasonal basal melting from distributed temperature sensing moorings

The article offers several mathematical tips and tools that can help children with their mathematic skills. It cites the I Say, You Say where the teacher names a sum less than 20 and the students are led to respond with the appropriate number. It refers to a whole-class game using a tic-tac-grid where students can revisit their computation skills. It provides an activity for children to learn odd and even numbers by placing 20 or less socks, gloves or mittens in a laundry basket.

The article offers tips related to classroom activities and teaching methods that would represent holidays. It suggests to let students display a clear cup of water which is then added with food coloring to represent water pollution that marks Earth Day. It instructs egg-hunting technique that provides questions on current topics, vocabulary words and math problems. It also suggests to allow students to go on a rhyme scheme scavenger hunt in honor of National Poetry Month.

Abstract: Primary pulmonary hypertension is a rare but deadly disease. Lungs extracted from PPH patients are deficient in endothelial nitric oxide synthase (eNOS), making the eNOS-null mouse a potentially useful model of the disease. To better understand the progression of pulmonary vascular remodeling in the congenital absence of eNOS, we induced pulmonary hypertension in eNOS-null mice using hypobaric hypoxia, and then quantified large artery structure and function in contralateral vessels. In particular, to assess structure we quantified diameter, wall thickness, and collagen, elastin and smooth muscle cell content; to quantify function we performed pressure-diameter tests. After remodeling, the pulmonary arteries had increased wall, collagen and elastin thicknesses compared to controls (P<0.05). The remodeled pulmonary arteries also had increased elastic moduli at low and high strains compared to controls (P<0.05). The increases in moduli at low and high strain correlated with increases in elastin and collagen thickness, respectively (P<0.05). These results provide insight into the mechanobiology of pulmonary vascular remodeling in the congenital absence of eNOS, and the coupled nature of these changes.

What''s all the buzz about ISO? What is ISO, and how could “manufacturing” standards possibly apply to health care, much less nursing? The International Organization of Standardization''s (ISO) 9001:2000 Quality Management System provides structure to support quality nursing care. The key word is “structure”, a framework for the provision of quality nursing care. Should an organization choose to adopt this system or choose an accreditation body that requires it, this is a workable system for nursing. However, nursing would not adopt this as a stand-alone initiative. This article will introduce the ISO 9001:2000 Standards and give examples of how this management system can support the nursing process to its ultimate goal of positive outcomes for patients. [Copyright &y& Elsevier]

The response of the two eulophid egg parasitoid species Chrysonotomyia ruforumand Dipriocampe diprionito sex pheromones of their sawfly hosts Diprion piniand Neodiprion sertiferwas studied in olfactometer bioassays. Females of C. ruforumwere arrested when exposed to odor of the tested major sex pheromone components of Diprion pini[acetate and propionate of (2S,3R,7R)-3,7–dimethyl-2–tridecanol] or Neodiprion sertifer[(2S,3S,7S)-3,7–dimethyl-2–pentadecyl acetate]. This behavioral response of C. ruforumwas observed whether (1) parasitoid females had oviposition experience with D. pinieggs or not, (2) parasitoid females emerged from D. pinieggs of a French population or from N. sertifereggs of a Finnish population, and (3) the tested sex pheromone concentration was low (1 ng/μl hexane) or high (100 ng/μl hexane). However, C. ruforumdid not behaviorally respond to a stereoisomer of the major sex pheromone component of N. sertifer, which is known to act as a sex pheromone antagonist [antagonist = (2S,3R,7R)-3,7–dimethyl-2–pentadecyl acetate]. Thus, C. ruforumresponded stereospecifically to the S,S,Sconfigured pheromone of N. sertifer, but not to the S,R,Rconfiguration. Females of the parasitoid D. diprioniwere also arrested by the tested major sex pheromone components of the host D. pini. The kairomonal effects of diprionid host sex pheromones on these egg parasitoids are compared to known responses of egg parasitoids to lepidopteran sex pheromones.

Benchmarking is one of the methods used in continuous quality improvement and other fiscal and clinical effectiveness programs. This article was prepared as a resource for nurses in practice. It provides an overview of benchmarking, including definitions, process, and nursing practice considerations.

The first detectable step in the degradation of human H4 histone mRNA occurs at the 3' terminus in a cell-free mRNA decay system (J. Ross and G. Kobs, J. Mol. Biol. 188:579-593, 1986). Most or all of the remainder of the mRNA is then degraded in a 3'-to-5' direction. The experiments described here were designed to determine whether a similar degradation pathway is followed in whole cells. Two sets of short-lived histone mRNA decay products were detected in logarithmically growing erythroleukemia (K562) cells. These products, designated the -5 and -12 RNAs, were generated by the loss of approximately 4 to 6 and 11 to 13 nucleotides, respectively, from the 3' terminus of histone mRNA. The same decay products were observed after a brief incubation in vitro. They were in low abundance or absent from cells that were not degrading histone mRNA. In contrast, they were readily detectable in cells that degraded the mRNA at an accelerated rate, i.e., in cells cultured with a DNA synthesis inhibitor, either cytosine arabinoside or hydroxyurea. During the initial stages of the decay process, as the 3' terminus of the mRNA was being degraded, the 5'-terminal region remained intact. These results indicate that the first detectable step in human H4 histone mRNA decay occurs at the 3' terminus and that degradation proceeds 3' to 5', both in cells and in cell-free reactions.

Sputter-deposited MoS2 films show excellent lubrication properties. Nevertheless, the film-substrate adherence is unsufficient and could not be improved by depositing interface layers. With the method of ion beam mixing by using argon and nitrogen beams of up to 400 keV energy a considerable enhancement of the endurance life was observed. Secondary ion mass spectrometry (SIMS) has been used to examine layers of 0.5 µm thickness. Variation of the ion species, dose and energy have been used for optimum endurance life. The results of tribological measurements compared to SIMS depth profiles are demonstrated and discussed.

No abstract

The use of peptides has attracted much interest in the development of synthetic vaccines. Although our current understanding of peptide antigens as immunogens has been greatly advanced recently, there still remain many obstacles. The B cell response elicited by a peptide antigen is governed by a number of poorly understood events such as epitope structure, T cell dependency and major histocompatibility complex restriction, adjuvancy, route of immunization, and immunogen stability. In this paper, we extend our previous studies on the problem of the topographical nature of antigenic sites on native protein antigens, in terms of how much molecular mimicry must be maintained in an antigenic determinant for the induction of high affinity antibodies specific for native protein. We show here that an antigenic epitope from the model contraceptive vaccine candidate lactate dehydrogenase (LDH-C4) can be rationally engineered into a highly structured conformation that mimics the corresponding site in the native three-dimensional protein. Our strategy is based on the selection of an antigenic segment which exhibits certain secondary structural properties and by design principles is fixed in three dimensions by appropriate grafting onto a supersecondary structural motif such as alpha beta, beta alpha beta, or beta alpha beta alpha. The biophysical data are consistent with the proposed secondary structures, and antibodies raised to the various construct show high affinity for the native protein. These studies lend further credence to the conformational nature of peptide epitopes and provide a basis for the rational design of peptide vaccines.

We have investigated the substrate specificity of an exonuclease that degrades human H4 histone mRNA, using synthetic RNA templates incubated in a cell-free mRNA decay system (Ross, J., and Kobs, G. (1986) J. Mol. Biol. 188, 579-593). Five RNAs that lacked poly(A), including histone, were degraded rapidly in vitro. Polyadenylated histone mRNA was degraded at least 10-fold more slowly than unmodified histone mRNA. Double-stranded RNA and DNA were very stable. Single-stranded DNA was degraded approximately 20-fold more slowly than single-stranded, non-polyadenylated RNA, and RNA with a 3' phosphoryl group was degraded more slowly than RNA with a 3'-hydroxyl group. Uncapped RNAs were degraded rapidly in the unfractionated system but were stable in reactions containing a ribosomal high salt wash extract. Therefore, the exonuclease activity released from ribosomes by high salt extraction was separated from the enzyme(s) that degraded uncapped RNAs.

We have described a cell-free system for studying mRNA degradation (Ross, J., and Kobs, G. (1986) J. Mol. Biol. 188, 579-593). Using that system we found that human H4 histone mRNA was degraded in a 3' to 5' direction by an exonucleolytic activity. Here we investigate several properties of the crude system and of the exonuclease. A RNase inhibitor, such as that from placenta, was required to block nonspecific ribonucleases and thereby to permit different mRNAs to be degraded at different rates. The histone mRNA exonuclease required divalent cation (magnesium) but not exogenously added ATP or GTP. It functioned efficiently at monovalent cation concentrations ranging from 0.5 to 200 mM. It was bound to ribosomes isolated from cells lysed in low salt buffers. However, it was eluted in active form from the ribosomes by exposing them to 0.3 M KCl. The enzyme rapidly degraded deproteinized, 32P-labeled histone mRNA prepared enzymatically.

The International Organization for Standardization (ISO) was used by British high-tech industries, such as munitions and manufacturing, to prove by recordkeeping that procedures were being followed. They were derived from the British Standards Institution (BSI) in 1979, primarily in manufacturing. The United States was using such standards for military procurement in 1959 and at NASA in 1962. [Copyright &y& Elsevier]

Ohne Zusammenfassung:

The article focuses on the increasing use of carbon fibers. According to the article, the second largest application after aerospace in the year 2010 will be in wind mills. Traditional applications such as sporting goods are forecast to grow slightly while industrial applications are forecast to show double-digit growth.

A letter to the editor is presented in response to the article "Split Fingertips," by Jerome J. Viviano in the February 2011 issue.

No relevant conflicts of interest to declare.

Abstract 938

2‐Nitro‐ and 2,4‐dinitro‐(trimethylstannyl)benzene (I) react with acetyl chloride in the presence of AlCl3to form the corresponding o‐(dimethylchlorostannyl)nitrobenzenes (II) with complexation of tin by the ortho‐nitro oxygen.

The reactions of imidazoles with OsO4both in the absence and presence of ligands other than imidazoles are studied kinetically.

The rate of formation of OsO4complexes with tetramethylethylenediamine, phenanthroline and 4,7‐diphenyl‐1,10‐phenanthroline disulfonate is investigated.

New ways of generating R3Sn· radicals, decoupled from the presence of R3SnH, which possess a high radical scavenging power, are developed and discussed: the spontaneous thermal dissociation of distannanes with bulky substituents, the thermal fragmentation of bisstannyl benzpinacols, the ketone‐sensitized mild photolysis of simple distannanes, and the mild photolysis of benzyltin compounds such as 9‐stannyl‐9,10‐dihydroanthracene.

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