cssi/SciSciGPT-SciSciNet huggingface dataset:
Non-Chromatographic Purification of Synthetic RNA Using Bio-Orthogonal Chemistry

Solid-phase synthesis of RNA oligonucleotides over 100 nt in length remains challenging due to the complexity of purification of the target strands from the failure sequences. This article describes a non-chromatographic procedure that will enable routine solid-phase synthesis and purification of long RNA strands. The optimized five-step process is based on bio-orthogonal inverse electron demand Diels-Alder chemistry between trans-cyclooctene (TCO) and tetrazine (Tz), and entails solid-phase synthesis of RNA on a photo-labile support. The target oligonucleotide strands are selectively tagged with Tz while on-support. After photocleavage from the solid support, the target oligonucleotide strands can be captured and purified from the failure sequences using immobilized TCO. The approach can be applied for purification of 76-nt long tRNA and 101-nt long sgRNA for CRISPR experiments. Purity of the isolated oligonucleotides should be evaluated using gel electrophoresis, while functional fidelity of the sgRNA should be confirmed using CRISPR-Cas9 experiments. © 2021 Wiley Periodicals LLC. Basic Protocol: Five-step non-chromatographic purification of synthetic RNA oligonucleotides Support Protocol 1: Synthesis of the components that are required for the non-chromatographic purification of long RNA oligonucleotides. Support Protocol 2: Solid-phase RNA synthesis.
Sodium hypochlorite-induced acute kidney injury

Sodium hypochlorite (bleach) is commonly used as an irrigant during dental proce­dures as well as a topical antiseptic agent. Although it is generally safe when applied topically, reports of accidental injection of sodium hypochlorite into tissue have been reported. Local necrosis, pain and nerve damage have been described as a result of exposure, but sodium hypo­chlorite has never been implicated as a cause of an acute kidney injury (AKI). In this report, we describe the first case of accidental sodium hypochlorite injection into the infraorbital tissue during a dental procedure that precipitated the AKI. We speculate that oxidative species induced by sodium hypochlorite caused AKI secondary to the renal tubular injury, causing mild acute tubular necrosis.
Supernumerary tooth in the right nostril associated with a median palatine cyst

Abstract An unusual case is presented to demonstrate a previously unreported anomalous position of a supernumerary tooth in association with a median palatine cyst.
Endoscopic ultrasound guided fine needle aspiration with fluorescence in situ hybridization analysis in 104 patients with pancreatic mass.

Background and Aim Diagnosis of pancreatic malignancy is often based on cytological specimens collected by endoscopic ultrasound guided fine needle aspiration (EUS FNA). Several factors can decrease sensitivity of EUS FNA for pancreatic cancer: well-differentiated tumors, pancreatitis, blood, necrosis and slides with low cellularity. The objective of this study is to report on the use of fluorescence in situ hybridization (FISH) analysis combined with cytology in pancreatic masses. Methods EUS database and medical records of patients referred for EUS between January 2009 through august 2013 were reviewed. Data on cytology, FISH and surgical pathology were reviewed. Surgical pathology, death or extended clinical follow-up were used to verify correct diagnosis of malignancy. FISH performed using a four-set DNA probe for chromosomes 3, 7, 17, and band 9p21 in patients with inconclusive immediate cytology reading. Sensitivity of cytology and FISH were compared. Results Study cohort comprised of 104 patients with FISH analysis on EUS FNA specimens of pancreatic masses (74 adenocarcinoma, 7 neuroendocrine tumor and 23 benign. Sensitivity of cytology and FISH for carcinoma was respectively: 62% and 81%. Sensitivity of FISH + cytology was 89%. The specificity of FISH and cytology was 100%. The most common abnormality on FISH was a 9p21 deletion seen in 43 patients (58%) followed by polysomy of 7 (46%). FISH detected malignancy in 23 patients with negative cytology. Conclusions In patients with inconclusive immediate cytology reading, FISH is superior to cytology and improves overall sensitivity. The 9p21 deletion is the most common abnormality seen in this cohort of patients with pancreatic cancer.
Ammonium Production in Sediments Inhibited with Molybdate: Implications for the Sources of Ammonium in Anoxic Marine Sediments

Ammonium production in the presence of specific inhibitors of sulfate reduction and methanogenesis was investigated in six marine sediments which differed in bulk properties and organic matter input. In all cases, little effect of the inhibitors on ammonium production was observed, although sulfate reduction was suppressed by molybdate. This gives evidence that the processes of fermentation and hydrolysis are of primary importance in ammonium generation at the sites studied. Although sulfate reduction rates may appear to be coupled to ammonium production rates, sulfate reduction does not necessarily contribute directly to generation of ammonium in marine environments.
Three-dimensional inverse scattering

We consider the problem of obtaining information about an inaccessible region of space from scattering experiments. Inverse scattering theory for the time-independent Schrodinger equation [Δ + h2−V(x)]φ(k,x) = 0 is summarized. It is most easily understood by considering the associated hyperbolic equation [Δ −aaa − V(x)]u(t,x) = 0. Particular attention is paid to those aspects of the theory that hold for the wave equation [Δ − n2 (x)att]u(t,x) = 0.
A Fresh Look at Tests for Nonliteral Copyright Infringement

A central puzzle for U.S. copyright law in the 20th and 21st centuries has been how to test for infringement of the exclusive right this law gives authors to control the reproduction of their works in copies. No subtlety of analysis is required when a work is copied word-for-word, line-for-line, or note-for-note or when second comers have made "merely colorable and fraudulent variations." But as Professor Kaplan once observed, "[w]e are in a viscid quandary once we admit that "expression" can consist of anything not close aboard the particular collocation in its sequential order." This Article offers several strategies for refining infringement analysis so that it becomes less viscid in cases alleging what the Nimmer treatise describes as "nonliteral" similarities between two works. Nonliteral infringement may arise, for instance, when a second comer appropriates detailed plot sequences from another author's drama but uses different dialogue.Part I discusses the five most frequently utilized tests for infringement of the reproduction right in nonliteral similarity cases. It explains how these tests are similar and different and why each test is flawed in one or more respects. Apart from these flaws, it is problematic that there are so many different tests and so little guidance about which test to use when.Part II recommends, among other things, that courts tailor infringement tests based on characteristics of the works at issue. The more artistic or fanciful a work is, for example, the more appropriate it is to focus infringement analysis primarily on similarities in the aesthetic appeal of the two works rather than on a dissective analysis of similarities and differences. The more factual or functional a works is, by contrast, the "thinner" is said to be its scope of protection, which suggests that infringement analysis should be more dissective in relation to similarities and differences of these works and less emphasis should be placed on impressions. Courts should also give more guidance about what constitutes protectable expression in copyright works and what aspects, besides abstract ideas, are unprotectable by copyright.
Molecular and topological characterization of the rat parotid Na+-K+-2Cl− cotransporter1

Abstract Na + -K + -2Cl − cotransporters play a central role in driving salt and water movements across secretory and absorptive epithelia. We report the cloning of the rat parotid secretory Na + -K + -2Cl − cotransporter, rtNKCC1. The predicted amino acid sequence of this protein is highly homologous to a previously cloned NKCC1 from the shark rectal gland and to mammalian NKCC1s cloned from several cultured cell lines, confirming the presence of the NKCC1 isoform in a naturally occurring mammalian secretory epithelium. In contrast to previously published NKCC1 clones, our sequence also includes an apparently complete 2680 bp 3′-UTR. Hydropathy analyses of rtNKCC1 predicts that this protein consists of large hydrophilic N and C termini (approx. 30 kDa and 50 kDa, respectively) flanking a central hydrophobic transmembrane region consisting of ten to 12 membrane spanning domains. In addition, we report the results of confocal immunofluorescent microscopic studies using rat parotid acini and antibodies directed against specific regions of the predicted N- and C-terminal portions of rtNKCC1. These studies demonstrate that the epitopes recognized by these antibodies are exposed in permeabilized but not in unpermeabilized cells, indicating that the predicted N and C termini of rtNKCC1 are intracellular.
The Thermodynamics of Mixed Solvent Cluster Ions: K+(CH3OH)n(H2O)m

One of the motivations for research on cluster ions is the parallel that the growth of cluster ions has with phenomena such as nucleation1,2 and solvation.3,4 For instance, the thermodynamics involved in the clustering of molecules about ions have been related to single ion heats of solvation.5,6 Most studies of clustering have been concerned with the sequential attachment of one particular species to an ion, as evident in a recent compilation7 of thermodynamic data on clusters ions. Few studies of competitive clustering by two different solvent species to yield mixed solvent cluster ions have been performed. In such systems, clustering may be enhanced or hindered by solvent-solvent interactions. Furthermore, the environment, as for example the natural atmosphere,8 is such that mixed cluster ions are prevalent and data for single component systems is inadequate. The purpose of this study is to expand the data base for binary solvent systems and to explore relationships with condensed phase binary solutions. Specifically, we have chosen to investigate the competitive clustering of water and methanol onto the potassium ion K+.
Decisions in force field development: an alternative to those described by Roterman et al. (J. Biomol. Struct. Dyn. 7, 421 (1989)).

Abstract We attempt to give an alternate point of view of the analysis by Roterman et al. (J. Biolmol. Struct. Dyn. 7, 415 (1989)). In particular, we argue for the use of flexible geometry and explicit inclusion of solvent effects in analyzing φ psi; maps of peptides.
A technologist perspective on half-time myocardial perfusion imaging: A promising new technology

2130 Objectives The well established procedure of SPECT myocardial perfusion imaging (MPI) currently accounts for almost half of clinical nuclear medicine imaging annually. The duration of a typical MPI study requires a few hours; therefore, limiting a technologist’s daily productivity. A new advanced reconstruction algorithm, Astonish (Philips Medical Systems), utilizes iterative reconstruction which allows image acquisition time to be reduced by 50%. We evaluated our experience with the new iterative reconstruction technique to confirm reproducibility and potential benefit for patient comfort and increasing productivity. Methods A rest/stress Tc-99m ECG-gated SPECT MPI was performed on 33 consecutive patients for full-time (FT) counts. FT data sets included 64 projections and filtered-backprojection processing. Half-time data (HTA) was created by retrospectively extracting 32 projections from the FT data and processed with the Astonish algorithm. HTA images were compared with FT images in random sequence by a nuclear medicine physician. Results The technologist successfully implemented processing of the 32 extracted frames with Astonish. Images produced from the HTA were deemed comparable in quality by nuclear medicine physician when shown in random order with the FT images. Conclusions Philips Astonish software proves to be advantageous to both patients and technologists without sacrificing diagnostic reliability. Half-time imaging will allow for increased throughput for MPI studies and increased patient comfort. The HT MPI is expected to be the standard protocol in our institution. Research Support S. Crandall1, R. Muzaffar2, W. Hubble1, C. Botkin1, D. Phegley3, N. C. Nguyen2, M.M. Osman2 1Department of Medical Imaging and Radiation Therapeutics, Doisy College of Health Science, St. Louis University, 2Department of Radiology, Nuclear Medicine, St. Louis University, 3Nuclear Medicine, Saint Louis University Hospital, St. Louis, M
Rapid and simple protein-stability screens : application to membrane proteins

Approximately 30% of the human genome, and likewise for other genomes, encodes membrane proteins. Also, the majority of known human pharmaceutical targets are membrane proteins. As a consequence, the future success of structure-based drug-design efforts will rely heavily on membrane-protein structural information. While a number of techniques are available to determine the structure of membrane proteins, crystallographic methods (either using two-dimensional or three-dimensional crystals) have been the most productive. Nonetheless, membrane-protein structure determination using crystallographic methods has encountered at least three serious bottlenecks: protein production, purification and crystallization. While a number of crystallization strategies for membrane proteins are available today, they all must ensure that the membrane protein of interest is thermodynamically stable for crystallization to be feasible. Thermodynamic stability is so fundamental to protein crystallization that it is often overlooked experimentally. Here, simple and effective protocols for determining the relative stabilities of membrane proteins using commercially available instruments and reagents are demonstrated. The results demonstrate suitability for the rapid screening of conditions that maximize protein stability using minimal amounts of reagents and protein.
Do leveraged exchange-traded products deliver their stated multiples?

Abstract Using the longest history of a U.S. equity market index, this paper simulates the return deviation and multiple deviation for Leveraged Exchange-Traded Products (LETPs) with different rebalancing frequencies, including daily, monthly, annually, and every five years, over various holding periods. We find that the general perception that daily-rebalanced LETPs are not suitable for long-term strategies is not substantiated. Advancing the analysis, we construct a comprehensive framework that determines the deviation of an LETP’s effective multiple from its stated product multiple under various rebalancing frequencies and holding period scenarios. The empirical framework and results from this paper hold the promise of guiding regulators, policy makers, and investors in their understanding of the tracking performance of LETPs.
Changing Patterns of Corporate Headquarter Influence, 1974–89

Research on the changing geography of metropolitan corporate headquarters (CH) influence has pointed to a decrease in importance for national centers and an increase in the importance of regional centers throughout the country. Theoretical explanations of this change have posited a linear evolutionary sequence from spatial and hierarchical concentration to dispersal. In this paper, the nature of change in metropolitan CH influence between 1974 and 1989 is examined, with a focus on three aspects of this process. First, the detailed sequence of dispersal within types of metropolitan region is explored. Second, the issue of how metropolitan CH influence changes over space is examined. Third, the impact of the recent restructuring of the US economy on metropolitan corporate influence is investigated. The results suggest that the linear evolutionary sequence model needs some modification. The major proportional shifts in CH influence are from New York to a select set of diversified regional centers that may be...
Mixing of siliciclastic and carbonate sediments in shallow shelf environments

The inhibiting effect that siliciclastic material has on carbonate-secreting organisms has lead to the generalization that sediments composed of mixtures of carbonate and siliciclastic material should rarely form. However, many modern and ancient shelf deposits contain a spectrum of sediments that are of “mixed” composition. The processes responsible for this mixing can be grouped into four categories: (1) punctuated mixing, where sporadic storms and other extreme periodic events transfer sediments from one depositional environment to another; (2) facies mixing, where sediments are mixed along the diffuse boundaries between contrasting facies; (3) in situ mixing, where the carbonate fraction consists of the autochthonous or parautochthonous death assemblages of calcareous organisms that accumulated on or within siliciclastic substrates; and (4) source mixing, where admixtures are formed by the uplift and erosion of nearby carbonate source terranes. The allochemical constituents of mixed sediments are both coralgal and foram-mollusc in composition. The foram-mollusc assemblage is the most common because of the effects of increased turbidity, unstable substrates, and the clogging of filter-feeding mechanisms associated with a siliciclastic influx.
On the Hungarian inventory control model

Abstract In this paper we recall and further develop an inventory model formulated by the author [Prekopa, A., 1965. Reliability equation for an inventory problem and its asymptotic solutions. In: Prekopa, A. (Ed.), Colloquia Applied Mathematics in Economics. Publ. House of the Hung. Acad. Sci., Budapest, pp. 317–327; Prekopa, A., 1973. Generalizations of the theorems of Smirnov with application to a reliability type inventory problem. Math. Operationsforschung und Stat. 4, 283–297] and Ziermann [Ziermann, M., 1964. Application of Smirnov’s theorems for an inventory control problem. Publications of the Mathematical Institute of the Hungarian Academy of Sciences Ser. B 8, 509–518] that has had wide application in Hungary and elsewhere. The basic assumption made in connection with this model is that the delivery of the ordered amount takes place in an interval, according to some random process, rather than at one time epoch. The problem is to determine that minimum level of safety stock, that ensures continuous production, without disruption, by a prescribed high probability. The model is further developed first by its combination with another inventory control model, the order up to S model and then, by the formulations of a static and a dynamic type stochastic programming models.
Electron beam simulation of disruptions into stainless steel

Abstract The effects of repetitive pulsed heating and melt layer formation on type 304 stainless steel are reported. A line-source electron beam with pulse times of 0.5 or 1.5 ms and power densities up to 100 kW/cm 2 has been used for 1–40 pulse cycles at 500°C substrate temperatures. Numerical calculations of the temperature profiles and their time evolution during melt layer formation are also carried out. Significant metallurgical changes are observed, both in the melt layers and in the adjacent heat-affected zone. Melt depths (10–20 μm) are consistent with calculations and the resolidified regions exhibit columnar or columnar-dendritic microstructure. Appreciable lateral motion within the molten layer results in very rough surfaces and localized cracking occurs. Extensive slip deformation is seen in the adjacent heat-affected zone, and low-cycle fatigue crack initiation is observed after only 20 pulses. Chemical changes in the stainless steel melt layer result from the preferential vaporization of Mn from the melt layer and correlate with the time in the liquid phase. We suggest that the preferential loss of high vapor pressure species such as Mn in the early phases of plasma device operation might provide a unique signature of the impurity introduction mechanism. Disruption melted compositions are distinctly different from the more-nearly stochiometric ratios of Mn/Cr/Ni expected for sputter erosion.
Through the eyes of the novice teacher: perceptions of mentoring support

This study examined the perceptions of elementary school beginning teachers (n = 136) across a Rocky Mountain state in the US regarding the mentoring support they received during their first year teaching. Beginning teachers were asked to report the types of mentoring support they received and to rate the helpfulness of this support on the Mentoring Support Survey. Individual item scores and scale scores are reported. An analysis of variance was then used to compare the scale scores of teachers with the administrator-facilitated mentoring supports of common planning time with their mentors and/or release time to observe other teachers. Results indicate that beginning teachers who received both common planning time with a mentor and release time to observe other teachers rated the mentoring experiences they had as significantly more helpful than beginning teachers who were not provided these mentoring supports. Of the two, provision of common planning time was the most important type of administrator-facil...
From Realism to Postmodernism and Beyond

Making Sense of International Relations Theory. Edited by Sterling-Folker Jennifer. Boulder: Lynne Rienner Publishers, 2005. 421 pp., $65.00 cloth (ISBN: 1-58826-378-9), $26.50 paper (ISBN: 1-58826-354-1). Jennifer Sterling-Folker's edited volume, Making Sense of International Relations Theory , contains a masterful discussion and application of the major theoretical approaches in international relations. The book contributes to our understanding of the similarities and differences in the core assumptions of eleven key perspectives in international relations and their variations. By applying varying strands of these approaches to a single case (Kosovo), the book also leaves readers with a tangible understanding of the major debates in the field of international relations. A detailed reading should leave the student not only with a thorough knowledge of the field of international relations (IR) but with a deep appreciation for its breadth and diversity. The central question in Making Sense of International Relations Theory is “how should we study the subject matter of international relations”? For the student, the book is both familiar and unique in comparison with other textbooks. On the one hand, like a typical course reader, the volume is arranged according to the various approaches (see also Der Derian 1995; Doyle and Ikenberry 1997; Betts 2005; Art and Jervis 2007). Yet, Making Sense of International Relations Theory is broader than many existing readers, and it includes approaches that disagree sharply with each other. It includes both positivist and postpositivist approaches. Moreover, the distinction between the two is outlined in Chapter One and reinforced in the nested nature of the book; it …
Power and Sample Size Calculations for Studies Involving Linear Regression

This article presents methods for sample size and power calculations for studies involving linear regression. These approaches are applicable to clinical trials designed to detect a regression slope of a given magnitude or to studies that test whether the slopes or intercepts of two independent regression lines differ by a given amount. The investigator may either specify the values of the independent (x) variable(s) of the regression line(s) or determine them observationally when the study is performed. In the latter case, the investigator must estimate the standard deviation(s) of the independent variable(s). This study gives examples using this method for both experimental and observational study designs. Cohen's method of power calculations for multiple linear regression models is also discussed and contrasted with the methods of this study. We have posted a computer program to perform these and other sample size calculations on the Internet (see http://www.mc.vanderbilt.edu/prevmed/psintro+ ++.htm). This program can determine the sample size needed to detect a specified alternative hypothesis with the required power, the power with which a specific alternative hypothesis can be detected with a given sample size, or the specific alternative hypotheses that can be detected with a given power and sample size. Context-specific help messages available on request make the use of this software largely self-explanatory.
Nevus of Ota With Contralateral Cerebral Melanoma

A case of unilateral nevus of Ota was associated with ipsilateral ocular melanocytosis and contralateral malignant melanoma of the CNS. The malignant neoplasm may have arisen from an area of bilateral leptomeningeal melanosis associated with unilateral nevus of Ota.
Near-Threshold Electron-Impact Excitation of the Low-Lying Rydberg States of Ethylene

Excitation functions for the 3B3u π → 3s and 3B1g and 1Ag π → 3p Rydberg states of ethylene have been measured and found to display structure due to the decay of core-excited anion states. Evidence is also provided that the π-1(3s)2 anion state undergoes significant decay to the π → π* singlet state in highly twisted configurations.
Laser thermal probe recanalization of occluded arteries.

Abstract Applications of laser energy for treatment of vascular disease have recently received much attention; metal-tipped laser probes are being investigated as a device for recanalization of occluded arteries, especially as an adjunct to balloon dilatation. Developments in instrumentation and techniques have reduced the incidence of complications, notably perforation, to an acceptable level. Initial data show that recanalization of iliac, femoral, and popliteal lesions can be accomplished in a majority of cases, with the chance of success being inversely proportional to the length of occlusion. Results in the tibial vessels are disappointing. Patency of the treated vessels at 12 months appears to be superior to that of percutaneous transluminal angioplasty for similar lesions but inferior to that of surgical bypass for all occlusions greater than 3 cm in length. (J Vasc Surg 1989;9:594–604.)
Superconducting wire contact to niobium thin films

Abstract A simple method is described for forming rugged superconducting solder contacts to niobium thin films, using an indium-lead-tin solder alloy.
The Pen and the Sword: Writing and Conquest in Caesar's Gaul

Julius Caesar was remembered in later times for the unprecedented scale of his military activity. He was also remembered for writing copiously while on campaign. Focusing on the period of Rome9s war with Gaul (58––50 BCE), this paper argues that the two activities were interrelated: writing helped to facilitate the Roman conquest of the Gallic peoples. It allowed Caesar to send messages within his own theater of operations, sometimes with distinctive advantages; it helped him stay in touch with Rome, from where he obtained ever more resources; and it helped him, in his Gallic War above all, to turn the story of his scattered campaigns into a coherent narrative of the subjection of a vast territory henceforward to be called ““Gaul.”” The place of epistolography in late Republican politics receives new analysis in the paper, with detailed discussion of the evidence of Cicero.
Specific inhibitor of FGF receptor signaling: FGF‐2‐mediated effects on proliferation, differentiation, and MAPK activation are inhibited by PD173074 in oligodendrocyte‐lineage cells

Multiple studies have shown that migration, proliferation, and differentiation of oligodendrocyte (OL) lineage cells are influenced by fibroblast growth factor-2 (FGF-2) signaling through its receptors (FGFR) FGFR-1, FGFR-2, and FGFR-3. We report the effectiveness and specificity of a unique inhibitor, PD173074, for inhibiting FGF receptor signaling in OL-lineage cells. Three FGF-mediated responses of OL progenitors and two of differentiated OLs were examined by immunofluorescence microscopy and immunoblotting. PD173074 effectively antagonized the effect of FGF-2 on proliferation and differentiation of OL progenitors in culture. One dose of PD173074 at nanomolar concentrations was sufficient to inhibit ongoing FGF-2 mediated proliferation for prolonged periods, in a non-toxic, dose-dependent manner. In contrast, platelet-derived growth factor (PDGF)-induced proliferation was unaffected by PD173074. Similarly, mitogen-activated protein kinase (MAPK) activation, a downstream event after activation of either FGFR or PDGFR, was also blocked by PD173074 in OL progenitors stimulated with FGF-2 but not PDGF. A general tyrosine kinase inhibitor (PD166285), however, antagonized both FGF-2- and PDGF-mediated responses. PD173074 also completely antagonized two phenotypic alterations of differentiated OLs, specifically downregulation of myelin proteins, and their re-entry into the cell cycle. We conclude that PD173704 is an effective and specific inhibitor for multiple FGF-2-mediated responses of both OL progenitors and differentiated OLs. This inhibitor provides a direct approach for identifying the importance of FGF signaling, comparable in effect to a knockout of all FGF receptors and all FGF ligands, while leaving other pathways unaffected. Thus, PD173704 is an excellent tool for investigating the role of FGF signaling in vivo in the context of combinatorial interactions of other signals.
Genes and gene expression in Lactococcus bacteriophages

Lactococcus lactis is extensively used in the production of cheese and cultured dairy products in industrial fermentations worldwide. Bacteriophage infection of L. lactis imposes a constant threat to the fermentation industry and represents the major cause of fermentation failure. Numerous phage defense strategies have been developed over the years to protect industrial starter cultures, particularly L. lactis. Numerous genes from lactococcal bacteriophages have been cloned and characterized and mechanisms that regulate their expression elucidated. Complete genome sequences of several L. lactis bacteriophages have also been determined. This accumulation of genetic information on lactococcal bacteriophages has led to a better understanding of the phage life cycle, host interactions, relationships between lactococcal phages, and possible patterns of phage evolution. These advances in molecular biology of lactococcal bacteriophages will be discussed with a view towards the development of novel and more effective phage defenses.
What is a class invariant

This paper is a progress report on our research into the problem of automatically identifying and using class invariants in object-oriented programs. We introduce an example of a class invariant in Java, and review applications for class invariants in software engineering tools and in compiler optimization. We then focus on an elementary problem of definition: what is a class invariant? This question gives an interesting perspective on programming language design. We conclude that there are many reasonable categories of class invariants, and that the problem of finding good definitions cannot be solved by a thought experiment. The only way to choose good categories is to experiment with the analysis of real programs, to see which categories of class invariant are actually useful. Our current research focuses on these experiments.
Juvenile Hormone: Effects on a Higher Dipteran

Injection of dl-juvenile hormone or C(17) methyl ester into Sarcophaga bullata larvae prevents puparium formation or arrests development at about the 3rd day of pupal-adult development. Topical application to the abdomens of young pupae results in the secretion of a second pupal cuticle. This is the first reported morphogenetic effect of juvenile hormone on a fly.
Crystal Environments Probed by EPR Spectroscopy. Variations in the EPR Spectra of CoII(octaethylporphyrin) Doped in Crystalline Diamagnetic Hosts and a Reassessment of the Electronic Structure of Four-Coordinate Cobalt(II)

The powder and single-crystal EPR spectra of CoII(OEP) (OEP is the dianion of octaethylporphyrin) doped into a range of diamagnetic crystals including simple four-coordinate hosts, H2(OEP), the triclinic B form of NiII(OEP), the tetragonal form of NiII(OEP) and ZnII(OEP); five-coordinate hosts, (μ-dioxane){ZnII(OEP)}2 and (py)ZnII(OEP); six-coordinate hosts, (py)2ZnII(OEP) and (py)2MgII(OEP); and hosts containing fullerenes, C60·2ZnII(OEP)·CHCl3, C70·NiII(OEP)·C6H6·CHCl3, and C60·NiII(OEP)·2C6H6 have been obtained and analyzed. Spectra were simulated using a program that employed the exact diagonalization of the 16 × 16 complex spin Hamiltonian matrix. The EPR spectra of these doped samples are very sensitive to the environment within each crystal with the crystallographic site symmetry determining whether axial or rhombic resonance patterns are observed. For CoII(OEP) doped into tetragonal NiII(OEP) (which displays a very large g⊥ of 3.405 and a very small g∥ of 1.544) and several other crystals containi...
Pneumatic switched angle spinning NMR probe with capacitively coupled double saddle coil.

Abstract Switched angle spinning (SAS) experiments can be used for generating isotropic–anisotropic correlations in oriented samples in a single experiment. In order for these methods to become widespread, specialized hardware is required. Here we describe the electronic and mechanical design and performance of a double-resonance SAS probe. Unlike many previous SAS probe implementations, the focus here is on systems where the dipolar couplings are partially averaged by molecular motion. This probe has a moving double saddle coil capacitively coupled to the stationary circuit. Angle switching is accomplished by a steam engine-type pneumatic mechanism. The speed and stability of the switching hardware for SAS experiments are demonstrated using spectra of model compounds.
Methane production from synthesis gas using a mixed culture ofR. rubrum M. barkeri, and M. formicicum

The components of synthesis gas, CO, H2, and CO2, may be converted into CH4 biologically through either acetate or H2/CO2 as intermediates. Of these two routes, conversion through H2/CO2 is preferred. This paper presents results of mixed-culture studies employing the photosynthetic bacteriumR. rubrum for converting CO to CO2 and H2 by the water gas shift reaction and two methanogens,M. formicicum andM. barkeri, for converting CO2 and H2 into CH4. Results are presented for triculture operation in two types of reactors, the packed bubble column and the trickle-bed reactor.
When bad is good enough: The lowest common denominator in reference publishing and reviewing

It does not seem too much to argue that high quality reference works, always crucial to the effective pursuit of research, have become increasingly important with the continuing proliferation of information as well as the increasingly complex need to capture ways of organizing it. Nor is it too much to say, unfortunately, that, even while this is so, reference works are well on their way to becoming the orphans of academic publishing. Today, more than ever, the publication of reference tools is largely in the hands of a few publishers, who depend on marketing techniques (particularly the packaging of books into series) rather than on the inherent quality of, or demonstrated need for, particular reference tools. Moreover (a point to which I will return), reference works are increasingly appearing in print as the inchoate and offhand products of desktop publishing.
Oral hygiene as a risk indicator of enamel and dentin caries.

UNLABELLED Dental researchers have postulated that the risk factors for enamel and dentin caries may not be the same. A review of the literature ascertained that data to support this theory are lacking. OBJECTIVES To evaluate the risk indicators of enamel and dentin caries of the permanent dentition in a study group who had limited access to fluorides and made limited use of dental services. METHODS The study was conducted in Goa, India. Data came from a cross-sectional survey of 1189 seventh grade children, which consisted of a clinical dental examination and a self-administered questionnaire to their parents. The cavitated and non-cavitated criteria were used to score for caries, and the Silness-Loe index for plaque. RESULTS The mean age of the children was 12.2 years. The percentage of children caries free in the permanent dentition was 22.2%, the mean+/-s for dmfs, enamel and dentin lesions were 4.20+/-5.10, 2.59+/-2.89 and 1.61+/-3.30 respectively, and the mean plaque score was 1.00+/-0.48. Results of regression analyses showed that the risk indicators of prevalence and severity of caries differed depending on lesion type. The only variable that was consistently a risk indicator of presence and severity of both dentin and enamel caries was poor oral hygiene. Mother's highest level of education and presence of fluorosis were also risk indicators of enamel and dentin caries. The presence of decayed primary teeth was a risk indicator of enamel caries; and fluorosis severity, use of fluoride toothpaste at the time of the survey, and toothbrushing frequency were risk indicators of dentin caries. The observed caries-oral hygiene association seen is explored further.
Evolution of perthite composition and microstructure during progressive metamorphism of hypersolvus granite, Rhode Island, USA

The Scituate Granite in central Rhode Island, USA contains very coarse alkali feldspar mesoperthite and has been subjected to prograde metamorphism subsequent to original igneous cooling. The modal abundance and grain size of relics of alkali feldspar mesoperthite decrease systematically as metamorphic grade increases. The composition and microstructures of coexisting phases in the relict perthite grains also vary systematically with increasing metamorphic grade. Microstructures coarsen and become more complex, and compositions record increasing metamorphic temperatures.
Complex and rate-dependent beat-to-beat variations in Ca2+ transients of canine Purkinje cells

Purkinje fibers play an essential role in transmitting electrical impulses through the heart, but they may also serve as triggers for arrhythmias linked to defective intracellular calcium (Ca(2+)) regulation. Although prior studies have extensively characterized spontaneous Ca(2+) release in nondriven Purkinje cells, little attention has been paid to rate-dependent changes in Ca(2+) transients. Therefore we explored the behaviors of Ca(2+) transients at pacing rates ranging from 0.125 to 3 Hz in single canine Purkinje cells loaded with fluo3 and imaged with a confocal microscope. The experiments uncovered the following novel aspects of Ca(2+) regulation in Purkinje cells: 1) the cells exhibit a negative Ca(2+)-frequency relationship (at 2.5 Hz, Ca(2+) transient amplitude was 66 ± 6% smaller than that at 0.125 Hz); 2) sarcoplasmic reticulum (SR) Ca(2+) release occurs as a propagating wave at very low rates but is localized near the cell membrane at higher rates; 3) SR Ca(2+) load declines modestly (10 ± 5%) with an increase in pacing rate from 0.125 Hz to 2.5 Hz; 4) Ca(2+) transients show considerable beat-to-beat variability, with greater variability occurring at higher pacing rates. Analysis of beat-to-beat variability suggests that it can be accounted for by stochastic triggering of local Ca(2+) release events. Consistent with this hypothesis, an increase in triggering probability caused a decrease in the relative variability. These results offer new insight into how Ca(2+) release is normally regulated in Purkinje cells and provide clues regarding how disruptions in this regulation may lead to deleterious consequences such as arrhythmias.
The Von Thuenen Paradigm, the Industrial-Urban Hypothesis, and the Spatial Structure of Agriculture

The industrial-urban hypothesis has stimulated considerable empirical research on the spatial structure of agriculture. The alternative paradigm of von Thuenen has had almost no such impact on agricultural research, but has been the mainstay of urban economic analysis. The two models are compared as scientific theories of agricultural land use in an attempt to identify their similarities and contradictions. After reinterpreting several industrial-urban studies from a von Thuenen viewpoint, an empirical discrimination between the two models is attempted with Brazilian data. A synthesis of the two paradigms provides a better explanation of agricultural structure than either alone.
Microfabrication of cylindrical microfluidic channel networks for microvascular research

Current methods for formation of microvascular channel scaffolds are limited with non-circular channel cross-sections, complicated fabrication, and less flexibility in microchannel network design. To address current limitations in the creation of engineered microvascular channels with complex three-dimensional (3-D) geometries in the shape of microvessels, we have developed a reproducible, cost-effective, and flexible micromanufacturing process combined with photolithographic reflowable photoresist and soft lithography techniques to fabricate cylindrical microchannel and networks. A positive reflowable photoresist AZ P4620 was used to fabricate a master microchannel mold with semi-circular cross-sections. By the alignment and bonding of two polydimethylsiloxane (PDMS) microchannels replicated from the master mold together, a cylindrical microchannel or microchannel network was created. Further examination of the channel dimensions and surface profiles at different branching levels showed that the shape of the microfluidic channel was well approximated by a semi-circular surface, and a multi-level, multi-depth channel network was created. In addition, a computational fluidic dynamics (CFD) model was used to simulate shear flows and corresponding pressure distributions inside of the microchannel and channel network based on the dimensions of the fabricated channels. The fabricated multi-depth cylindrical microchannel network can provide platforms for the investigation of microvascular cells growing inside of cylindrical channels under shear flows and lumen pressures, and work as scaffolds for the investigation of morphogenesis and tubulogenesis.
Comparison of the LH2 Antenna Complexes of Rhodopseudomonas acidophila (Strain 10050) and Rhodobacter sphaeroides by High-Pressure Absorption, High-Pressure Hole Burning, and Temperature-Dependent Absorption Spectroscopies

The cyclic (Cn) light harvesting 2 (LH2 or B800−850) complexes of Rps. acidophila (strain 10 050) and Rb. sphaeroides, isolated under identical conditions, are compared using the title spectroscopies. Thermal broadening and shifting data for the B850 absorption band reveal a structural change near 150 K for both species in the glycerol:water solvent used. The linear regions of thermal broadening above and below this temperature are shown to be consistent with dephasing via phonon-assisted relaxation between the B850 ring's exciton levels, which contribute to the B850 absorption band. The theoretical model used predicts, for both species, that the nearest neighbor coupling(s) between bacteriochlorophyll a (BChl a) molecules of the B850 ring is (are) significantly stronger, ca. 35%, for the low-temperature structures. Moreover, the linear thermal broadening rates of Rb. sphaeroides are significantly lower than those of Rps. acidophila for both the low- and high-temperature regions. Analysis of the differenc...
A Mathematical Trip to Princeton

Please send all submissions to Mathematical Tourist Editor, Dirk Huylebrouck, Aartshertogstraat 42, 8400 Oostende, Belgium e-mail: dirk.huylebrouck@gmail.com T he phone rings and a familiar voice speaks. ‘‘Since you’re going to Princeton this summer, you’ll surely be taking a tour of the Princeton campus, and their math department. When you go there, be sure to take note of a sculpture near the Math Department Commons Room. This piece involves three mathematicians: One was the artist, another commissioned the piece, and the third was the one to whom it was dedicated. When you get back, tell me what you ... what? No time? I’m sorry, you make the time.’’ Orders are orders, so you make the time and tour the beautiful Princeton University Campus. There, you find that sculpture, along with an ivory tower and many other sights worth seeing. The Princeton University mathematics department may or may not be in first place in the mythical USA Mathematics Marathon, but it is certainly up there in the lead pack. Two Fine Halls have housed the Princeton math department, both named for Henry Burchard Fine (1858–1928), the first chair of mathematics at Princeton and President of the American Mathematical Society in 1911–1912. The first building was opened in 1930; it was renamed Jones Hall in 1968 when the second and current Fine Hall was built. In the immediate vicinity of the current Fine Hall are one building and two sculptures worth a second look. The building is the Lewis Science Library [4], which opened in 2008. Designed by architect Frank O. Gehry, it is a mathematical marvel in its own right. (Go inside and look around: It’s time well spent.) Viewed from the Fine Hall tower, it resembles a cell complex (Figure 1). The library is one among many architectural gems at Princeton, as an architect friend from high-school and his historian wife demonstrated during a campus tour. The library stands next to Fine Hall on what was formerly the site of an informal volleyball court used by the math faculty and students. Apparently, when Fields Medalist William Thurston was on the faculty, he supplied the net, which he put up in the morning and took down in the evening. Two steel sculptures of mathematical character stand in the vicinity. The older one is Alexander Calder’s 26-foot sculpture ‘‘Five Disks: One Empty;’’ [3] dedicated in 1971, it stands in the Fine Hall courtyard plaza between the mathematics and physics departments. (Maybe it looks like a horse, and maybe it doesn’t–Modern Art is like that.) The newer one is Richard Serra’s ‘‘The Hedgehog and the Fox,’’ [5] a trio of 90-foot long and 15-foot high nested serpentine steel ribbons standing just east of the library. It’s fun to walk through this huge installation and listen to the echoes. Appropriately, when viewed from the Fine Hall tower, ‘‘The Hedgehog and the Fox’’ looks like a triple integral sign (Figure 2).
Physiological control of heat exchange rates in the texas tortoise gopherus berlandieri

Abstract 1. 1. Gopherus berlandieri heats significantly faster than it cools. 2. 2. Withdrawal of the head greatly affects the head-body temperature relationship. When withdrawn, the head heats and cools slower than the body. When extended, the head heats and cools faster than the body. This is attributed to the greater insulation afforded to the head by the body when the head is withdrawn. 3. 3. Since this species spends much of its time amongst vegetative cover, physiological augmentation of heat gain would be of adaptive significance. 4. 4. It is speculated that head temperature regulation may play a significant role in the determination of midday and evening retreat in this and other species of tortoises.
Comparison of Two Cognitive Strategies in Treatment of a Patient with Generalized Anxiety Disorder

The relative efficacy of two cognitive strategies—coping self-statements and paradoxical intention—for reducing anxiety were compared using an alternating treatment design for a patient with generalized anxiety disorder. While cognitive restructuring appeared to be effective clinically in treating this patient, results did not suggest an advantage in effectiveness of one cognitive strategy over the other. However, although measures did not indicate a differential effectiveness between the two cognitive strategies, the patient reported that she found the coping self-statement strategy more helpful, a preference that continued at 1-yr. follow-up.