cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamic mechanical properties of poly-n-docosyl methacrylate☆

The real (J′) and imaginary (J″) components of the complex compliance have been measured between 24 and 100 cycles/sec. at 59.0°C. and 65.2°C. for poly-n-docosyl methacrylate. The results, reduced to 62°C., provide the relaxation and retardation spectra over a short region which encompasses the maximum of the latter. The logarithm of the monomeric friction coefficient (units dyne-sec./cm.) is estimated to be −7.2. The maximum in the retardation spectrum for the butyl, hexyl, octyl, and docosyl methacrylate polymers is inversely proportional to the 3.4 power of the polymer density expressed in monomoles per cubic centimeter. The same relation is followed, with essentially the same proportionality constant, for solutions of poly-n-butyl methacrylate in diethyl phthalate. It is concluded that the number of strands per cubic centimeter in the entanglement network of a methacrylate polymer depends only on the concentration of chain backbones regardless of whether they are diluted by solvent molecules or by side groups.
Second order Stark effect on the optically detected signals of the zero-field transitions of the triplet state

Abstract The second order Stark effect has been demonstrated on the phosphorescence microwave double resonance (PMDR) signals of p -benzoquinone in 1,4-dibromobenzene host at 1.6 K. It is shown that possible estimates of the zero-field parameters of the higher triplet state mixed by the field with the lowest triplet state can be determined from the observed Stark shift of the zero-field triplet spin transitions. Furthermore, by using polarized microwaves in the double resonance experiments, and from the anisotropy of the Stark effect on the PMDR signal, the direction of the transition moment to the state that is mixed by the field can also be determined.
Sensitivity of planetary boundary layer atmosphere to historical and future changes of land use/land cover, vegetation fraction, and soil moisture in Western Kentucky, USA

Changes in land use land cover (LULCC), vegetation fraction (FV), and soil moisture affects land surface atmosphere interactions, characteristics of planetary boundary layer (PBL), and near surface atmospheric moisture content. Previous studies have investigated impacts of LULC, FV, and soil moisture changes on atmosphere separately. The present study investigates the combined impacts of changes in LULC, FV, and soil moisture, on PBL atmosphere and near surface atmospheric moisture content. The study is set in western region of Kentucky, USA. We have used the Noah land surface scheme and MM5 model for this purpose. The study used two nested domains. The current land use land cover of the inner domain was changed to grass, forest, and bare soil to represent historical changes and potential near future modifications. Subsequently, FV and soil moisture were systematically changed for each of the land uses. The simulations have found that changes of current land use to grass within the inner domain increases latent heat flux, dew point temperature, relative humidity, and equivalent potential temperature. It was found that height of the PBL was reduced and development of circulation cells was visible along land use land cover discontinuity. Changes in horizontal and vertical wind field were also reported. FV changes for grass further magnified these impacts. For example, decrease or increase in FV has decreased or increased latent heat flux. Similar response of other PBL parameters could be found for changes in FV along with LULC. It was also found that if we replaced forest with lower FV by grass with higher FV, the impacts could cancel each other. Changes to forest and bare soil land use types and lower FV for forest also produced generally similar types of responses. Soil moisture changes, particularly drying, further impacted these responses. This study finds that increase in FV counteracts impacts of soil moisture reduction up to a level. Overall, grass produced moister PBL and lowered the height of PBL and LCL. It is interesting to note that during nighttime the impacts of LULC, FV and soil moisture changes were diminished. These changes not only modified meso-scale wind fields but also potential for convective development. It was concluded that similar experiments needed to be undertaken for convectively conducive environments to better understand the combined impacts of changes in LULC, FV and soil moisture.
Evidence of a second stationary state of the O4 molecule from density functional theory

Abstract Molecular orbital calculations of the O 4 molecule using density functional theory, employing a 6-311G ∗∗ basis set predicts a stationary state of a four bonded closed oxygen configuration having D 2 d symmetry describing a torsionally distorted square in agreement with previous work. The calculations also predict the existence of another stationary state (isomer), not previously considered, which consists of a three bonded open chain structure and having a lower energy than the D 2 d structure. Calculations of the frequencies of this structure by density functional theory yield no negative frequencies confirming it is a stationary state. The density functional method predicts the structure to have C 2 h symmetry similar to the experimental geometry of the isoelectronic N 2 F 2 .
New method improves estimation of subdaily rainfall statistics

Daily rainfall data are readily available, but in many locations there are few rain gauges that provide subdaily rainfall data. Hydrologic models often deal with this problem by generating synthetic hourly rainfall series by assuming a temporal scaling behavior. However, Beuchat et al. found that the particular scaling laws may apply only to specific climates, and it is difficult to produce regional scaling laws. Therefore, they propose a new approach to estimating subdaily rainfall statistics using a mathematical technique called multivariate adaptive regression splines (MARS).
Experiences of Staff Nurses during Clinical Learning

Professional Issues Paper Presentation Objective To understand the unstructured experiences of staff nurses in an obstetric unit with undergraduate nursing students present. Design Naturalistic inquiry. Setting Family birth center in Pacific Northwest. Sample Convenience sample, 12 English speaking, baccalaureate-prepared registered nurses (RNs) who worked in unstructured manner with nursing students. Methods Semistructured interviews were conducted and recorded. Participants shared their experiences of working with students. Data were analyzed using an interpretive continuous approach according to Lincoln and Guba's elucidation of Glaser and Strauss's constant-comparative method, and data were stored, organized, and coded. Data collection and analysis ceased when categories were saturated and no new information surfaced. Demographic data were analyzed using descriptive statistics. An experienced qualitative researcher provided oversight to ensure accuracy. Credibility, transferability, dependability, confirmability were used to ensure trustworthiness. Results Five themes emerged as follows: giving and receiving : working with students provided nurses opportunities to give back to their profession—nurses learned from students; advancing professionally and personally : many nurses took advantage of workplace incentives to gain additional compensation and opportunities; balancing act : nurses balanced their typical workloads with student learning needs and provision of safe, quality care—students slowed nurses down; getting to know and working with you : nurses worked to know student personally and tailored the learning experience—nurses desired students be prepared; past and present : clinical experiences exert long lasting impressions. Conclusion/Implications for Nursing Practice Clinical learning is integral to nursing education and preparation for professional practice. Increased enrollments in baccalaureate nursing programs require more staff nurses to supervise students in the workplace. Researchers have found students’ learning, impressions of nursing, and perceptions of clinical learning are greatly influenced by nurses in the workplace, and working with students is a benefit for many nurses. Workplace learning may increase when students are prepared prior to entering clinical settings. Nurses working with students should be judiciously selected. Future research should be aimed at discovering tangible rewards and benefits that motivate nurses to work in an unstructured manner with students and determine how students in the workplace influence patient safety and quality of care.
Search for a novel killer toxin in yeast Pichia pastoris.

Certain yeast strains secrete a protein toxin, which inhibits the growth of sensitive pathogens and yeasts. Studies have shown that production of the toxin is dependent on presence of linear, double-stranded DNA plasmids in the killer yeasts. In the yeast Pichia pastoris, two linear double-stranded DNA plasmids have been identified. In the present study, the search for toxin-producing capability in P. pastoris has been conducted. No killer activity could be detected when 14 different indicator strains were tested.
Simultaneous catalytic reaction of O2 and NO with CO and solid carbon

Abstract Notwithstanding its thermodynamic instability and associated strong oxidation potential nitric oxide reacts slower with carbon than does oxygen. Both reactions are catalyzed by iron oxide but the sequence of the reactions remains the same. When a dilute mixture of CO, O2 and NO in helium is passed over a catalyst consisting of iron oxide supported on carbon a characteristic selectivity in the overall process is observed. The oxygen reacts catalytically with the solid carbon while the nitric oxide reacts, also catalytically, on the surface of the iron oxide with the gaseous carbon monoxide. In this system as well, the oxygen reacts faster than the nitric oxide.
EMT tumorigenesis in the mouse mammary gland

The term EMT (epithelial–mesenchymal transition) is used in many settings. This term is used to describe the mechanisms facilitating cellular repositioning and redeployment during embryonic development and tissue reconstruction after injury. Recently, EMT has also been applied to potential mechanisms for malignant progression and has appeared as a specific diagnostic category of tumors. In mice, most ‘EMT’ tumors have a spindle cell phenotype. The definition of EMT is controversial because spindle cell tumors are not common in humans, especially in human breast cancers. Spindle cell tumors of the mouse mammary gland have been observed for many years where they are usually classified as sarcomas or carcinosarcomas. Genetically engineered mice develop mammary spindle cell tumors that appear to arise in the epithelium and undergo EMT. To better understand the origin and evolution of these spindle cell tumors in progression and metastases, seven cohorts of spindle cell tumors from the archives of the University of California, Davis Mutant Mouse Pathology Laboratory were studied. This study provides experimental and immunohistochemical evidence of EMT showing that dual epithelial and mesenchymal staining of tumor spindle cells identifies some, but not all, EMT-type tumors in the mouse. This suggests that potential EMT tumors are best designated EMT-phenotype tumors.
Use of sympathetic alpha antagonists in the management of pediatric urologic disorders.

PURPOSE OF REVIEW To update the physician regarding the use of alpha-adrenergic antagonists in the management of various pediatric urologic problems. RECENT FINDINGS The use of alpha-adrenergic antagonist for the treatment of pediatric urologic disorders has expanded greatly over the past decade. This review summarizes the current use of these medications in the treatment of pediatric voiding dysfunction, neurogenic bladder, chronic lower urinary tract symptomatology, idiopathic urethritis, and the passage of ureteral calculi. SUMMARY Currently alpha antagonist therapy although not useful in the primary treatment of voiding dysfunction is equivalent in potency to biofeedback therapy for the treatment of recalcitrant voiding dysfunction. In the management of neurogenic bladder and chronic lower urinary tract symptomatology, alpha antagonists working alone or in conjunction with anticholinergic medications will improve clinical symptoms, increase bladder compliance, and decrease detrusor instability. In addition, alpha antagonists may decrease the intensity and duration of symptoms in patients with idiopathic urethritis. Compared with placebo, alpha-adrenergic antagonists will also aid significantly in the spontaneous passage of distal ureteral calculi, thereby reducing the need for surgical intervention and analgesia. The findings noted above significantly expand the clinical usefulness of alpha antagonist therapy within the field of pediatric urology.
Management of Patients with Supra ventricular Tachycardia Using Amiodarone Therapy

Amiodarone has emerged as a potent agent for the management of patietits with reentrant supra ventricular tachycardias, atrial flutter, atrial fibrillation, and dysrhythmias associated with the preexcitation syndromes. Efficacy is reported betiveen 50 and 90% dependent upon the nature of the primary rhythm disturbance and population studied. Electrophysiological studies have not in general been helpful in predicting outcome with this agent. The drug may produce a wide array of toxic side effects, requiring cessation of therapy in less than 10% of patients. Our approach to the use of this agent relegates it to a second or third line of therapy in view of its complex pharmacokinetics and wide array of side effects.
Multiple forms of sarc gene proteins from Rous sarcoma virus RNA

Abstract In a previous study we were able to identify two proteins of 25,000 and 18,000 daltons that were made from RNA of transforming virions of Rous sarcoma virus (RSV) and that were missing from the translation products of a transformation-defective deletion mutant of RSV. In the present study we have separated RSV virion RNA on sucrose gradients and have determined that the two putative sarc gene products are synthesized as doublets from an mRNA of approximately 18 S. There also appear to be several other sizes of virion mRNA that direct the synthesis of other viral proteins. These data are discussed in terms of the structure of the RSV genome. In addition to the 25,000- and 18,000-dalton doublets, there also is a 60,000-dalton protein whose synthesis is directed by 18S viral RNA from transforming virion of RSV. Peptide mapping has shown that the 60,000- and 25,000-dalton doublet are structurally related. In addition, the use of two-dimensional gel electrophoresis has allowed us to resolve both bands of the 25,000-dalton doublet into several differently charged species.
New focus of U.S. industrial firms in the Pacific Basin

Abstract Strategies of industrial firms in Pacific Asia have involved transfers of production technologies, policies toward workers, and marketing tactics. Prevailing strategies to date, largely emphasizing cost minimization, have caused significant alienation of Asians as workers and citizens. The authors argue for a change in management focus in the 1990s, an era in which Pacific Asia is rapidly transforming into a dynamic growth market rather than merely a low-cost production site.
Immunochemical studies on the N-acetyllactosamine β-(1→6)-linked trisaccharide specificity of Ricinus communis agglutinin

Abstract The combining site of Ricinus communis agglutinin (RCA 1 ) was studied by quantitative precipitin and precipitin inhibition assays. Of 31 complex carbohydrates tested, all except active and inactive antifreeze glycoproteins, Streptococcus group C polysaccharide, and native rat salivary glycoprotein, reacted strongly, and 22 completely precipitated the lectin, indicating that RCA 1 has both a broad range of affinity and a low solubility of its carbohydrate-bound complex. Of the monosaccharides and glycosides tested for inhibition of precipitation, p -nitrophenyl β- d -galactopyranoside was the best. It was about 6.4 times better than methyl β- d -galactopyranoside. The β anomer of glycosides of d -galactose was much more potent than the corresponding α anomer. Among the oligosacharides tested, β- d -Gal p -(1→4)-β- d -Glc p NAc-(1→6)- d -Gal was the best inhibitor, which was ∼2/3 as active as p -nitrophenyl β- d -galactopyranoside. It was ∼1.4 times as active as β- d -Gal-(1→4)- d -GlcNAc ( N -acetyllactosamine), twice as active as β- d -Gal-(1→3)- d -GlcNAc, and 4.5 times more active than lacto- N -tetraose. From the results, it can be concluded that; (a) hydrophobic interaction is important for binding; (b) the combining site of this lectin is at least as large as a trisaccharide; and (c) of the compounds studied, the trisaccharide β- d -Gal p -(1→4)-β- d -Glc p NAc-(1→6)- d -Gal was the most complementary to the human blood group I Ma determinant β- d -Gal p -(1→4)-β- d -Glc p NAc-(1→6)- d -Gal.
Energy yields for hydrogen cyanide and formaldehyde syntheses: the HCN and amino acid concentrations in the primitive ocean.

Prebiotic electric discharge and ultraviolet light experiments are usually reported in terms of carbon yields and involve a large input of energy to maximize yields. Experiments using lower energy inputs are more realistic prebiotic models and give energy yields which can be used to estimate the relative importance of the different energy sources on the primitive earth.
Superconductivity: A celebration of pairs

It is fifty years since John Bardeen, Leon Cooper and Bob Schrieffer presented the microscopic theory of superconductivity. At a wonderful conference in Urbana the 'good old days' were remembered, and the challenges ahead surveyed.
Grand Theory and Context‐Specificity in the Study of Forest Dynamics: Forest Transition Theory and Other Directions

This article critically reviews forest transition theory, which posits a decline in forest cover followed by expansion during the course of development. Whereas case studies in advanced industrial nations provided an empirical foundation, more recent cross-national modeling efforts and studies in developing regions have raised doubts. Forest transition theory has limitations in its concept of forests, its treatment of forest dynamics, its explanation for forest transitions, and its generalizability. This critique provides the basis for research needs to link studies of forest dynamics on various timescales to other land use/land cover research, as via historical-comparative methods and interdisciplinary theoretical frameworks.
Three observations on wages and measured cognitive ability

Abstract This paper summarizes our recent research on the relationship between wages and measured cognitive ability. In it, we make three main points. First, we find that wage payment by ability does vary across race and gender in the US, and that the fraction of wage variance explained by cognitive ability is modest. Second, measured cognitive ability and schooling are so highly correlated that one cannot separate their effects without imposing strong, arbitrary parametric structure in estimation which, when tested, is rejected by the data. Third, controlling for cognitive ability, personality traits (socialization skills) are correlated with earnings, although they primarily operate through schooling attainment.
Poly(ethylene glycol)-based ammonium ionenes containing nucleobases

Abstract Adenine-functionalized ionenes (ionene-A) and thymine-functionalized ionenes (ionene-T) were synthesized from novel nucleobase-containing monomers from an efficient aza-Michael addition to an acrylate precursor. Complexes of ionenes with nucleobase-containing guest molecules (n-butyl thymine, nBT and n-butyl adenine, nBA) exhibited well-defined complementary hydrogen bonding interactions. Job’s analysis revealed a 1:1 stoichiometry for the hydrogen-bonded complexes of [ionene-A]:[nBT], [ionene-T]:[nBA], and [nBA]:[nBT]. A mathematical fit of the chemical shifts to the Benesi–Hildebrand method revealed the association constants of 94 M−1, 130 M−1, and 137 M−1 for complexes of [ionene-A]:[nBT], [ionene-T]:[nBA], and [nBA]:[nBT], respectively. Furthermore, DSC thermograms of 1:1 [ionene-A/T]:[guest molecule] complexes showed the disappearance of the melting transition for the guest molecule, confirming the absence of macrophase separation of the nucleobase guest in the polymer matrix. Morphological studies including atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS) revealed a microphase-separated morphology for the nucleobase-containing ionenes and less defined microphase separation for the 1:1 complexes.
Combined effects of interferon α and interleukin 2 on the induction of a vascular leak syndrome in mice

Immunotherapy with interleukin 2 (IL-2) alone or in combination with lymphokine-activated killer cells can mediate tumor regression in mice and in man. Further dose escalation of IL-2 along with lymphokine-activated killer cells has been prevented by the development of a vascular leak syndrome produced by IL-2. Because we have found that interferon α (IFN-α) or tumor necrosis factor (TNF-α) has synergistic antitumor effects when administered together with IL-2, we have tested the vascular leakage induced by these lymphokine combinations. We used a murine model to quantify vascular leakage by measuring the extravasation of 125I-albumin from the intravascular space as well as the wet and dry lung weights after treatment with different cytokines. Cytokines (or Hanks balanced salt solution) were administered to C57BL/6 mice and 4 h after the last injection the vascular leak was quantified. IFN-α alone did not cause extravasation of radiolabel or increase in wet lung weights, though when given in combination with IL-2, significantly greater extravasation (P<0.01) as well as increase in lung water weights (P<0.05) was observed compared to the response in mice treated with IL-2 alone. IFN-α in combination with IL-2 induced significant vascular leakage earlier than the response induced by IL-2 alone. For example treatment with IFN-α and IL-2 induced accumulation of 14674±605 cpm in the lungs at day 1 while IL-2 alone induced 12340±251 cpm. The degree of vascular leakage was highly related to the dose of IFN-α administered along with IL-2 and increased vascular leak syndrome was evident even at low doses (5000 units) of IFN-α. Immunosuppression of mice by pretreatment irradiation (500 rad) markedly decreased the development of vascular leak syndrome induced by IL-2 and IFN-α. Interestingly IFN-γ and TNF-α did not induce vascular leakage in the lungs when given alone, and did not add or synergize with IL-2 in causing the syndrome. Thus the administration of IFN-α in combination with IL-2 produces a dose-limiting vascular leakage that is more severe than that caused by IL-2 alone, and may be mediated, directly or indirectly by host radiosensitive cells.
Identifying Least-Cost Sources of Required Fertilizer Nutrients

Agricultural producers should evaluate trade-offs between application costs and blending fees when applying two or more fertilizer mixtures to satisfy their ex ante fertilizer requirements in an economical manner. This decision situation is modeled using a linear programming procedure designed for practical use as a computerized decision-making aid. Results from a trial application of the methodology suggest this aid can be of significant value to producers confronted with such decisions.
Amine-Assisted Delamination of Nb2C MXene for Li-Ion Energy Storage Devices

2D Nb2CTx MXene flakes are produced using an amine-assisted delamination process. Upon mixing with carbon nanotubes and filtration, freestanding, flexible paper is produced. The latter exhibits high capacity and excellent stability when used as the electrode for Li-ion batteries and capacitors.
Self‐defocusing of pulsed light beams

Beam spreading by thermal blooming of intense light pulses is treated by self‐similar methods. Scale parameters for the lateral spreading of the beam and the decrease of the maximum intensity are derived. The system of self‐similar ordinary differential equations is derived. Estimates are calculated at which beam‐energy thermal blooming exceeds linear absorption.
Mechanics of muscular organs

Abstract A continuum theory for predicting the stress and deformation in muscular organs is formulated. It is shown how the experimentally determined stress-strain law for individual muscle fibers may be incorporated into a general continuum theory for the muscular organ as a whole. The behavior of individual muscle fibers is described by Hill's model in which a contractile element is arranged with a series elastic element and a parallel elastic element. The stress tensor for the organ is decomposed into the sum of two terms—one representing the active contraction of the muscle fibers, the other denoting the remaining passive stress.
Estimation of size of bacteria by low-angle light-scattering measurements: theory

Abstract Light scattering methods have potential in microbiology beyond the use of turbidity to measure biomass. High-angle light-scattering measurements are largely a measure of details of the anatomy of cells (outer envelope, pili, glagella and inclusions such as storage granules, ribosomes, etc.). Without information about these detailed features of cell morphology low-angle light-scattering has information about the shape, biomass and global size. Computer calculations are presented that can be used to obtain these parameters from angular intensities. These non-destructive measurements can be made under non-perturbing conditions but require well collimated illumination (specifically a helium-neon laser) for measurements at very low angles. Probably the major use of this technique will be as an absolute method for measuring the mean size of prokaryotes under natural conditions without artifacts introduced during preparation of the cells for the electron microscopic viewing.
The tolls of privacy: An underestimated roadblock for electronic toll collection usage

Abstract Despite continuing population and economic growth in the Bay Area, the rate of adoption of FasTrak, the electronic toll collection system employed in California, has been significantly lower than similar systems in comparable urban areas of the United States. Prior economic research suggests drivers in California's urban areas have a revealed willingness to pay for the convenience of FasTrak that exceeds their current cost of FasTrak. Using survey results and other research, we find the slower progress of FasTrak is partially related to consumers' value of perceived privacy overweighing the implicit value of convenience. Similarly, our research suggests that either a change in consumers' perception of privacy in the FasTrak system, or a fiduciary compensation must be offered to Bay Area drivers' in exchange for their perceived reduction of privacy, if any significant increase of FasTrak usage is to be achieved.
Multiframe x-ray imaging with a large-area 40ps camera

We have developed a large area short pulse framing camera that is capable of sixteen frames and shutter times of 40 ps per frame. This is accomplished with a high fidelity electrical circuit and a L/D equals 20 microchannel plate, driven by a short pulse (80 ps) high amplitude electrical driver. We show results of this work we have done to support this type of shutter time and the difficulties associated with large area high speed shuttering.
The fate of inhaled (14)C-labeled PCB11 and its metabolites in vivo.

Background The production ban of polychlorinated biphenyl (PCB) technical mixtures has left the erroneous impression that PCBs exist only as legacy pollutants. Some lower-chlorinated PCBs are still being produced and contaminate both indoor and ambient air.
EXTENSIONS OF THE STANDARD MODEL

In these lectures we focus on several issues that arise in theoretical extensions of the standard model. First we describe the kinds of fermions that can be added to the standard model without affecting known phenomenology. We focus in particular on three types: the vector-like completion of the existing fermions as would be predicted by a Kaluza-Klein type theory, which we find cannot be realistically achieved without some chiral symmetry; fermions which are vector-like by themselves, such as do appear in supersymmetric extensions, and finally anomaly-free chiral sets of fermions. We note that a chiral symmetry, such as the Peccei-Quinn symmetry can be used to produce a vector-like theory which, at scales less than MW, appears to be chiral. Next, we turn to the analysis of the “second hierarchy problem” which arises in Grand Unified extensions of the standard model, and plays a crucial role in proton decay of supersymmetric extensions. We review the known mechanisms for avoiding this problem and present a new one which seems to lead to the (family) triplication of the gauge group. Finally, this being a summer school, we present a list of homework problems.
Dissolvable membranes as sensing elements for microfluidics based biological/chemical sensors

We demonstrate a chemical and biological sensing mechanism in microfluidics that transduces chemical and biological signals to electrical signals with large intrinsic amplification without need for complex electronics. The sensing mechanism involves a dissolvable membrane separating a liquid sample chamber from an interdigitated electrode. Dissolution of the membrane (here, a disulfide cross-linked poly(acrylamide) hydrogel) in the presence of a specific target (here, a reducing agent—dithiothreitol) allows the target solution to flow into contact with the electrode. The liquid movement displaces the air dielectric with a liquid, leading to a change (open circuit to ∼1 kΩ) in the resistance between the electrodes. Thus, a biochemical event is transduced into an electrical signal via fluid movement. The concentration of the target is estimated by monitoring the difference in dissolution times of two juxtaposed sensing membranes having different dissolution characteristics. No dc power is consumed by the sensor until detection of the target. A range of targets could be sensed by defining membranes specific to the target. This sensing mechanism might find applications in sensing targets such as toxins, which exhibit enzymatic activity.
Structural insights into the function of aminoglycoside-resistance A1408 16S rRNA methyltransferases from antibiotic-producing and human pathogenic bacteria

X-ray crystal structures were determined of the broad-spectrum aminoglycoside-resistance A1408 16S rRNA methyltransferases KamB and NpmA, from the aminoglycoside-producer Streptoalloteichus tenebrarius and human pathogenic Escherichia coli, respectively. Consistent with their common function, both are Class I methyltransferases with additional highly conserved structural motifs that embellish the core SAM-binding fold. In overall structure, the A1408 rRNA methyltransferase were found to be most similar to a second family of Class I methyltransferases of distinct substrate specificity (m7G46 tRNA). Critical residues for A1408 rRNA methyltransferase activity were experimentally defined using protein mutagenesis and bacterial growth assays with kanamycin. Essential residues for SAM coenzyme binding and an extended protein surface that likely interacts with the 30S ribosomal subunit were thus revealed. The structures also suggest potential mechanisms of A1408 target nucleotide selection and positioning. We propose that a dynamic extended loop structure that is positioned adjacent to both the bound SAM and a functionally critical structural motif may mediate concerted conformational changes in rRNA and protein that underpin the specificity of target selection and activation of methyltransferase activity. These new structures provide important new insights that may provide a starting point for strategies to inhibit these emerging causes of pathogenic bacterial resistance to aminoglycosides.
The Interaction between (Ca2++ Mg2+)-ATPase and the Soluble Activator (Calmodulin) in Erythrocytes Containing Haemoglobin S

Summary. In normal erythrocytes, a membrane-bound (Ca2++ Mg2+)-ATPase is stimulated by a soluble activator, calmodulin. Since cells containing Hb S accumulate excessive Ca2+, the defect could lie in either the (Ca2++ Mg2+)-ATPase or calmodulin. To decide between these two possibilities, we prepared (Ca2++ Mg2+)-ATPase from erythrocytes of normal (AA), sickle cell trait (AS) and sickle cell disease (SS) individuals. Calmodulin was prepared from haemolysates from AA and SS erythrocytes. The enzyme prepared from SS ghosts had lower specific activity than that from AA membranes. Furthermore, calmodulin from either source did not stimulate the ATPase of SS erythrocytes. Enzyme from AS cells had specific activity similar to that of enzyme prepared from SS membranes. The enzymatic activity of a mixed cell population obtained from an SS patient 8 d following exchange-transfusion was proportional to the per cent Hb A. These results indicate that calmodulin is unable to interact with the enzyme site on the SS membrane. This inability is believed to be due to a specific property of the membrane and not an abnormality of calmodulin itself.
Strong infrared emission from the extrasolar planet HD 189733b

We report detection of strong infrared thermal emission from the nearby (d = 19 pc) transiting extrasolar planet HD 189733b by measuring the flux decrement during its prominent secondary eclipse. A 6 hr photometric sequence using Spitzer's infrared spectrograph in peak-up imaging mode at 16 μm shows the secondary eclipse depth to be 0.551% ± 0.030%, with accuracy limited by instrumental baseline uncertainties, but with 32 σ precision (σ = 0.017%) on the detection. The 16 μm brightness temperature of this planet (1117 ± 42 K) is very similar to the Spitzer detections of TrES-1 and HD 209458b, but the observed planetary flux (660 μJy) is an order of magnitude greater. This large signal will allow a detailed characterization of this planet in the infrared. Our photometry has sufficient signal-to-noise ratio (~400 per point) to motivate a search for structure in the ingress/egress portions of the eclipse curve, caused by putative thermal structure on the disk of the planet. We show that by binning our 6 s sampling down to ~6 minute resolution, we detect the modulation in the intensity derivative during ingress/egress due to the overall shape of the planet, but our sensitivity is not yet sufficient to distinguish between realistic models of the temperature distribution across the planet's disk. We point out the potential for extending Spitzer secondary eclipse detections down to the regime of transiting hot Neptunes, if such systems are discovered among nearby lower main-sequence stars.
A computational study into the reactivity of epichlorohydrin and epibromohydrin under basic conditions in the gas phase and solution

Ab initio molecular orbital calculations were carried out on epibromohydrin (EBH) and epichlorohydrin (ECH) in an attempt to elucidate their reactivity with respect to a hard nucleophile, hydroxide. These systems were modeled in both the gas phase and a polar solvent under basic conditions. In the gas phase, it was determined that a direct displacement mechanism (nucleophilic attack at the C1 position) was operative for EBH, while an indirect pathway (nucleophilic attack at the C3 position and subsequent intramolecular displacement) was followed for ECH. In an acetone solution, only the indirect displacement mechanism was found to occur. An electrostatic argument is advanced to account for this behavior in polar solution. Copyright © 2007 John Wiley & Sons, Ltd.
Developing an Operating Budget for Extended Family, Inc.: A Not‐for‐Profit Human Service Organization

In this case, you will develop an operating budget for Extended Family, Inc., a not‐for‐profit (NFP) human service organization. Completing this budget successfully requires a high level of decision making, as you must determine the number of cost pools and allocation bases upon which common costs are to be allocated to the organization's three revenue‐generating programs. This case will expose you to many real‐world issues that NFP financial managers confront when they prepare operating budgets. These issues include: (1) allocating revenue among programs; (2) distinguishing among program, administrative, and fundraising costs; (3) properly treating temporarily restricted contributions; and (4) facing an array of ongoing financial challenges connected with NFPs.
Holographic Mutual Information at Finite Temperature

Using the Ryu-Takayanagi conjectured formula for entanglement entropy in the context of gauge-gravity duality, we investigate properties of mutual information between two disjoint rectangular sub-systems in nite temperature relativistic conformal eld theories in d-spacetime dimensions and non-relativistic scale-invariant theories in some generic examples. In all these cases mutual information undergoes a transition beyond which it is identically zero. We study this transition in detail and nd universal qualitative features for the above class of theories which has holographic dual descrip- tions. We also obtain analytical results for mutual information in the specic regime of the parameter space. This demonstrates that mutual information contains the quantum entanglement part of the entanglement entropy, which is otherwise dominated by the thermal entropy at large temperatures.
IKKϵ Signaling: Not Just NF-κB

IκB kinases (IKKs) are key components of NF-κB signaling pathways in innate immunity and inflammation. Surprisingly, three recent reports implicate IKKs in Drosophila in seemingly unrelated functions, including non-apoptotic caspase activation and cytoskeleton organization.
Longitudinal and Radial Mhd Linear Induction Accelerator with Hot Conducting Plasma Core

Conceptual design of linear induction accelerator is presented using for the core continuum a highly conductive plasma with sustained pumping velocity. Karlovitz criterion of boundary theory is employed in the process of design.
Optical waveguiding in suspensions of dielectric particles

Waveguiding is observed in a liquid core/liquid cladding waveguide containing a suspension of dielectric particles in the core. The threshold for guiding is determined by the numerical aperture of the effective refractive index.
The Timothy syndrome mutation differentially affects voltage- and calcium-dependent inactivation of CaV1.2 L-type calcium channels

Calcium entry into excitable cells is an important physiological signal, supported by and highly sensitive to the activity of voltage-gated Ca2+ channels. After membrane depolarization, Ca2+ channels first open but then undergo various forms of negative feedback regulation including voltage- and calcium-dependent inactivation (VDI and CDI, respectively). Inactivation of Ca2+ channel activity is perturbed in a rare yet devastating disorder known as Timothy syndrome (TS), whose features include autism or autism spectrum disorder along with severe cardiac arrhythmia and developmental abnormalities. Most cases of TS arise from a sporadic single nucleotide change that generates a mutation (G406R) in the pore-forming subunit of the L-type Ca2+ channel Ca(V)1.2. We found that the TS mutation powerfully and selectively slows VDI while sparing or possibly speeding the kinetics of CDI. The deceleration of VDI was observed when the L-type channels were expressed with beta1 subunits prominent in brain, as well as beta2 subunits of importance for the heart. Dissociation of VDI and CDI was further substantiated by measurements of Ca2+ channel gating currents and by analysis of another channel mutation (I1624A) that hastens VDI, acting upstream of the step involving Gly406. As highlighted by the TS mutation, CDI does not proceed to completeness but levels off at approximately 50%, consistent with a change in gating modes and not an absorbing inactivation process. Thus, the TS mutation offers a unique perspective on mechanisms of inactivation as well as a promising starting point for exploring the underlying pathophysiology of autism.
Defect tolerance for molecular electronics-based nanofabrics using built-in self-test procedure

A BIST procedure is proposed for testing and fault tolerance of molecular electronics-based nanofabrics. The nanofabrics are assumed to include up to 10/sup 10/ gates: this requires new test strategies that can efficiently test and diagnose the nanofabric in a reasonable time. Our BIST procedure utilizes nanofabric's components as test pattern generator and response analyzer. The proposed technique tests the components in parallel with a low number of test configurations reducing the test time significantly. Due to high defect density of nanofabrics, a diagnostic procedure needs to be done to achieve a high recovery. A defect database is created to be used by compilers during configuring the nanofabric to avoid defective components. This results in a reliable system constructed using unreliable components.
Thymic Hyperplasia in a Patient with Graves’ Disease

A 23-yr-old man who was previously healthy was evaluated after a fall. Computed tomography of the chest showed an anterior mediastinal mass. Percutaneous biopsy showed benign thymic tissue. Three months later the patient developed ophthalmopathy and signs and symptoms of hyperthyroidism. Serum-TSH level measured less than 0.004 IU/ml (0.35–5.50 IU/ml), serum-free T4 4.93 ng/dl (0.61– 1.76 ng/dl), and serum-thyroid peroxidase antibody more than 70 IU/ml ( 2 IU/ml). Radioiodine uptake was increased in a diffusely enlarged gland. Based on these findings, the patient was diagnosed with Graves’ disease. The patient was treated with radioactive iodine. His thyroid decreased substantially in size, but a repeat chest computed tomography 1 month later demonstrated persistence of the mediastinal mass (Fig. 1). The patient complained of pain and a sensation of fullness and obstruction in his chest; thus, radical thymectomy was performed. The thymus was enlarged and measured 11.5 7.5 3 cm. Pathology revealed thymic follicular hyperplasia with focal germinal center formation. There is a rare but well-documented association between Graves’ disease and thymic hyperplasia (1). In most cases thymic enlargement is minimal; however, it may occasionally present as an appreciable anterior mediastinal mass (2). Whereas surgical resection has been a common treatment of such a mass, the literature supports following up the mass closely (3). A decrease in size after treatment of the hyperthyroidism supports the diagnosis of thymic hyperplasia, and thymectomy can be avoided (3). Clinicians should be aware of the usually benign clinical course of thymic hyperplasia associated with Graves’ disease.
Informatics in Radiology: Measuring and Improving Quality in Radiology: Meeting the Challenge with Informatics

The issue of quality in radiology is discussed and the use of informatics technologies to measure and improve quality in radiology is described, with emphasis on the ways in which these tools will help radiologists practice safely and effectively and prove the value of their services.
Supplemental Antibiotics to Enhance the Action of Gentamicin in Pseudomonas and Mixed Infections

A survey of 66 patients treated with gentamicin alone indicated that 14 patients showed persistence of Pseudomonas or a mixed flora, and they required additional treatment. A study of a mixed infection (peritonitis) in mice and of an experimental infection of mice with Pseudomonas aeruginosa was made with gentamicin treatment alone or in combination with other antibiotics. The challenge organisms were given ip, and the treatment sc 1 hr later. Gentamicin was significantly beneficial in the treatment of peritonitis. Ampicillin, chloramphenicol, penicillin G, or streptomycin could be added without any loss of benefit, but only kanamycin-gentamicin treatment was better than gentamicin alone. Gentamicin was also effective in treating the challenge with Pseudomonas. Ampicillin or carbenicillin in addition to gentamicin did not produce any less benefit, but no clear-cut gain was produced by adding one of a variety of antibiotics to the basic gentamicin regimen.
Care of the underserved: faculty development needs assessment.

Introduction Because role models are crucial to training physicians to care for the underserved, we examined pedi-atric faculty’s knowledge, attitudes, self-efficacy, skills, and precepting behaviors regarding care for this population. Methods Faculty knowledge, attitudes, self-efficacy, and skills/precepting behaviors were surveyed. Results Fifty-five (65%) of 85 faculty responded. The mean (standard deviation) knowledge score was 5.9 (1.3) of 8 possible. More than one-third of faculty did not recognize the eligibility criteria, services, and outcomes associated with common resources serving the underserved. Overall attitudes toward underserved families were positive, mean 3.3 (0.3), as was mean self-efficacy, 3.0 (0.7). Self-efficacy was lowest for accessing community resources for underserved families, 2.4 (0.7). Although most faculty performed the surveyed skills, fewer than 50% reported precepting of these same skills with students. Precepting was lowest for accessing public and community resources. Conclusions Low rates of student precepting as well as specific knowledge and self-efficacy deficits highlight potential targets for faculty development.
Surgical outcomes of internal fixation and revision arthroplasty for periprosthetic humeral fractures: commentary on an article by Jaron R. Andersen, MD, et al.: "Surgically treated humeral shaft fractures following shoulder arthroplasty".

Postoperative periprosthetic fractures of the humerus can be challenging for both the patient and the surgeon given that these fractures are difficult to treat and have high complication rates. The incidence of periprosthetic fractures after anatomic shoulder replacements has been reported to be 0.6%1. A recent series included four patients with a periprosthetic fracture after a reverse-geometry shoulder arthroplasty2, but we do not know of any other report or data on periprosthetic fractures after reverse shoulder arthroplasty. As the numbers of anatomic and reverse total shoulder replacements increase, orthopaedic surgeons will more commonly encounter these difficult fractures. Wright and Cofield proposed a classification system for periprosthetic humeral fractures3, although this system has not been validated and its ability to guide treatment has not been evaluated. In their study, Andersen and colleagues described the operative treatment and surgical outcomes of thirty-six periprosthetic fractures after anatomic (nineteen) or reverse (seventeen) shoulder arthroplasty. Seventeen patients had a well-fixed prosthesis and …
Reproducibilities of Carbon and Germanium Thermometers at 4.2°K

In the last few years a program of precision secondary thermometry in the 2–4°K range has been greatly facilitated by the use of metallic storage dewars which contain a few liters of liquid helium. The temperature distribution in these nearly “constant temperature” baths have been explored with both resistance and vapor-pressure thermometers. The results of these investigations, and also the reproducibilities of resistance thermometers, are presented.