cssi/SciSciGPT-SciSciNet huggingface dataset:
Defective Hematopoiesis and Erythroid Differentiation Resulting From Telomerase Deficiency

Abstract Abstract 2410 Telomere shortening and anemia are common in bone marrow failure syndromes (BMF) such as dyskeratosis congenita (DKC), acquired aplastic anemia and myelodysplastic syndromes (MDS). Components of the telomerase complex including TERT, TERC and Dyskerin are mutated in multiple BMF syndromes, strongly suggesting a link between aberrant telomere maintenance and BMF. However, the specific defects in hematopoiesis that lead to BMF have not been completely defined. To better understand the effects of telomere shortening on hematopoiesis, we crossed Tert−/− mice for five successive generations to derive 5th generation Tert−/− (G5 Tert−/−) mice with short telomeres. The G5 Tert−/− mice were smaller in size and their peripheral blood cell counts had significantly reduced numbers of red blood cells and hemoglobin content (p-value Disclosures: No relevant conflicts of interest to declare.
Sequence of the R1 plasmid and comparison to F and R100

The R1 antibiotic resistance plasmid, originally discovered in a clinical Salmonella isolate in London, 1963, has served for decades as a key model for understanding conjugative plasmids. Despite its scientific importance, a complete sequence of this plasmid has never been reported. We present the complete genome sequence of R1 along with a brief review of the current knowledge concerning its various genetic systems and a comparison to the F and R100 plasmids. R1 is 97,566 nucleotides long and contains 120 genes. The plasmid consists of a backbone largely similar to that of F and R100, a Tn21-like transposon that is nearly identical to that of R100, and a unique 9-kb sequence that bears some resemblance to sequences found in certain Klebsiella oxytoca strains. These three regions of R1 are separated by copies of the insertion sequence IS1. Overall, the structure of R1 and comparison to F and R100 suggest a fairly stable shared conjugative plasmid backbone into which a variety of mobile elements have inserted to form an "accessory" genome, containing multiple antibiotic resistance genes, transposons, remnants of phage genes, and genes whose functions remain unknown.
Product market competition, competitive strategy, and analyst coverage

This paper examines how product market competition and strategic interactions among peer firms influence analyst coverage. First, we hypothesize that product market competition increases both the demand and supply of analyst coverage. Using three variations of industry concentration ratios and a firm specific measure of competition, we test and find a positive and significant effect of market competition on analyst coverage. Second, we explore an information transfer channel through which product market affects analyst coverage. We hypothesize that information flows more freely among firms selling similar products. Such information flows lowers analyst information collection and processing costs, which in turn increases analyst coverage. Using product similarity index developed by Hoberg and Phillips (J Polit Econ 124(5):1423–1465, 2016) to capture the effect of information transfer, we find that analyst coverage increases with product similarity. Third we examine the role of competitive strategy in analyst coverage. We split our sample into markets of strategic complements and strategic substitutes. We find that the effect of market competition and analyst coverage is more pronounced in markets where firms compete as strategic complements.
Pregnancy and the Acceptability of Computer-Based Versus Traditional Mental Health Treatments.

Abstract Background: Recent recommendations urge increased depression screening in pregnant and postpartum women, potentially increasing demand for treatment. Computer-based psychotherapy treatments may address some of perinatal women's unique mental health treatment needs and barriers. Materials and Methods: We conducted a quantitative survey of pregnant women (≥12 weeks of gestation) on preferences regarding computer-based therapies compared with traditional therapies (psychotherapy and medication). Nonpregnant women and men served as comparison groups. Participants were provided descriptions of three computer-based therapies: video telehealth therapy (VTT), computer-assisted therapy (CAT), and self-guided online therapy (SGO). Participants were asked to select all options that they would consider for treatment as well as first choice preference. The Patient Health Questionnaire-9 (PHQ-9) assessed current depressive symptomatology, and the Mini International Neuropsychiatric Interview (MINI) assessed ps...
The use of (18)F-2-fluorodeoxyglucose (FDG) to label antibody fragments for immuno-PET of pancreatic cancer.

We generated 18F-labeled antibody fragments for positron emission tomography (PET) imaging using a sortase-mediated reaction to install a trans-cyclooctene-functionalized short peptide onto proteins of interest, followed by reaction with a tetrazine-labeled-18F-2-deoxyfluoroglucose (FDG). The method is rapid, robust, and site-specific (radiochemical yields > 25%, not decay corrected). The availability of 18F-2-deoxyfluoroglucose avoids the need for more complicated chemistries used to generate carbon–fluorine bonds. We demonstrate the utility of the method by detecting heterotopic pancreatic tumors in mice by PET, using anti-Class II MHC single domain antibodies. We correlate macroscopic PET images with microscopic two-photon visualization of the tumor. Our approach provides easy access to 18F-labeled antibodies and their fragments at a level of molecular specificity that complements conventional 18F-FDG imaging.
Empathetic Communication: Bridging Differences in a Global Context

The aim of this chapter is to describe the concept of empathetic communication and its relevance in facilitating communication between people with communication disabilities and typical communicators. After a description of the concept of empathetic communication, we will discuss different examples of interactions to enhance understanding of manifestations of empathetic communication. These examples include an interaction between a caregiver and an adult with disabilities as well as a cross-cultural interaction between a therapist and a mother of a child with disabilities. Finally, some conclusive comments are made.
A Quantitative Point-of-Need Assay for the Assessment of Vitamin D 3 Deficiency

Vitamin D is necessary for the healthy growth and development of bone and muscle. Vitamin D deficiency, which is present in 42% of the US population, is often undiagnosed as symptoms may not manifest for several years and long-term deficiency has been linked to osteoporosis, diabetes and cancer. Currently the majority of vitamin D testing is performed in large-scale commercial laboratories which have high operational costs and long times-to-result. Development of a low-cost point-of-need assay could be transformative to deficiency analysis in limited-resource settings. The best biomarker of vitamin D status, 25hydroxyvitamin D3 (25(OH)D3), however, is particularly challenging to measure in such a format due to complexities involved in sample preparation, including the need to separate the marker from its binding protein. Here we present a rapid diagnostic test for the accurate, quantitative assessment of 25(OH)D3 in finger-stick blood. The assay is accompanied by a smartphone-assisted portable imaging device that can autonomously perform the necessary image processing. To achieve accurate quantification of 25(OH)D3, we also demonstrate a novel elution buffer that separates 25(OH)D3 from its binding protein in situ, eliminating the need for sample preparation. In human trials, the accuracy of our platform is 90.5%.
Performance Measurement of Building Sheet-Metal Ductwork Prefabrication under Batch Production Settings

AbstractMechanical contractors have been among the very early pioneers of construction prefabrication by moving a significant amount of work to sheet metal fabrication shops off-site to produce com...
Learning Technology Integration From a Service-Learning Project: Connecting Preservice Teachers to Real-World Problems

Background: Stand-alone educational technology courses have long faced the challenge of connecting preservice teachers to real-world problems of using technology for teaching and learning. Although...
Taking the Peppered Moth with a Grain of Salt

H. B. D. Kettlewell's (1955, 1956) classic field experiments on industrial melanism in polluted and unpolluted settings using the peppered moth, Biston betularia, are routinely cited as establishing that the melanic (dark) form of the moth rose in frequency downwind of industrial centers because of the cryptic advantage dark coloration provides against visual predators in soot-darkened environments. This paper critiques three common myths surrounding these investigations: (1) that Kettlewell used a model that identified crypsis as the only selective force responsible for the spread of the melanic gene, (2) that Kettlewell's field experiments alone established that selection for crypsis was the most important factor in the spread of melanic forms, and (3) that Kettlewell's investigations in an unpolluted wood near Dorset constituted a control for his earlier Birmingham studies (contra Hagen 1993, 1996). This analysis further identifies two features that distinguish manipulative experiments in evolutionary biology from experiments in other contexts. First, experiments in evolutionary biology rest on a wealth of information provided by strictly observational ecological studies; in the absence of such information experiments in evolutionary biology make no sense. Second, there is a trade-off between how much control investigators have over the conditions being studied and how informative the results of the experiment will be with regard to natural populations.
Responses of cleaved caspase-8 and -12 apoptotic pathways to 12 week treadmill exercise in aging rat skeletal muscle

Previously our laboratory demonstrated that exercise training (ET) attenuated age-induced muscle fiber atrophy, caspase-3 cleavage, and pro-apoptotic Bcl-2 signaling in the rat white gastrocnemius....
Gelfand Pairs Associated with Finite Heisenberg Groups

We examine a family of finite Gelfand pairs which arise in connection with Heisenberg groups H = H n (F) over finite fields of odd characteristic. The symplectic group Sp(n, F) acts on H by automorphisms. A subgroup K of Sp(n, F) yields a Gelfand pair (K, H) when the K-invariant functions on H commute under convolution. This is equivalent to the restriction of the oscillator representation to K being multiplicity free. An interesting example of this type occurs with K a finite analog of the unitary group U(n).
Is Management of Central Retinal Artery Occlusion the Next Frontier in Cerebrovascular Diseases

Central retinal artery occlusion (CRAO) is a medical emergency that, if not treated, may result in irreversible loss of vision. It continues to be an important cause for acute painless loss of vision. Amaurosis fugax or "transient CRAO" has long been considered an equivalent of transient cerebral ischemic event. Animal models, in addition to data from retrospective and randomized clinical studies, provide valuable insights into the time interval for irreversible retinal ischemia. Subset analyses from 2 large studies of patients with CRAO show benefit from treatment with thrombolysis within 6 hours from symptoms onset. Significant workflow improvements after the intra-arterial therapy trials for acute ischemic stroke have occurred world over in last 5 years. Patients with CRAO are uniquely suited to receive maximum benefits from the changes in workflow for treatment of patient's acute ischemic stroke. Just as in clinical triage of acute ischemic stroke, correct and timely diagnosis of patients with CRAO may help in preventing visual loss. The approach to acute ocular ischemia should mimic that used for acute brain ischemia. Comprehensive stroke centers would be ideal triage centers for these patients in view of availability of multidisciplinary participation from vascular neurology, neuroendovascular surgery, and ophthalmology. Time is Retina!
Culinary Tourism in Central America: A Cross-Analysis of Government Tourism Websites

Food and beverage are growing tourism niches and have yet to realize their potential in Central America. This study explores how culinary tourism is promoted in official tourism websites of Hondura...
Multidivisional firms, internal competition, and comparative advantage: Baye et al. Meet Neary

Abstract We present a tractable general equilibrium model to capture the effects of divisionalization on trade in oligopolistic industries. Divisionalization reduces the incentives for diversification in production. The extensive margins of trade expand as a result of divisionalization, facilitating specialization toward the direction of comparative advantage, with exports rising in the case of domestic divisionalization and imports rising in the case of foreign divisionalization. This effect of internal competition on specialization is magnified when competition between divisions is staggered. The factor market effects of divisionalization, domestic and/or foreign, strengthen the expansionary effects on the extensive margins of trade.
Self-Esteem and the Development of Partisan Identity:

Why do young people choose to identify with a political party? While existing accounts emphasize the importance of political socialization, we propose that young people’s self-perceptions also infl...
High performance III-V photoelectrodes for solar water splitting via synergistically tailored structure and stoichiometry.

Catalytic interface of semiconductor photoelectrodes is critical for high-performance photoelectrochemical solar water splitting because of its multiple roles in light absorption, electrocatalysis, and corrosion protection. Nevertheless, simultaneously optimizing each of these processes represents a materials conundrum owing to conflicting requirements of materials attributes at the electrode surface. Here we show an approach that can circumvent these challenges by collaboratively exploiting corrosion-resistant surface stoichiometry and structurally-tailored reactive interface. Nanoporous, density-graded surface of ‘black’ gallium indium phosphide (GaInP2), when combined with ammonium-sulfide-based surface passivation, effectively reduces reflection and surface recombination of photogenerated carriers for high efficiency photocatalysis in the hydrogen evolution half-reaction, but also augments electrochemical durability with lifetime over 124 h via strongly suppressed kinetics of corrosion. Such synergistic control of stoichiometry and structure at the reactive interface provides a practical pathway to concurrently enhance efficiency and durability of semiconductor photoelectrodes without solely relying on the development of new protective materials. Photoelectrochemical water splitting presents an integrated means storing sunlight into fuels, yet high optical losses and corrosion limit device performance. Here, authors boost absorption and durability in gallium-indium phosphide photocathodes via a sulfurized and nanostructured protection layer.
Hypochlorous acid reversibly inhibits caspase-3: a potential regulator of apoptosis.

Caspase-3 is involved in apoptosis. Here, we examine whether hypochlorous acid (HOCl), a final product of myeloperoxidase (MPO), is a modulator of caspase-3 at relatively low concentrations and als...
Impact of Increasing the Number of Type-3 Wind Turbines on Stability of Power-system Dynamics

This paper outlines an approach to perform small-signal stability analysis of a power network with conventional synchronous generators and a wind farm composed of Type-3 wind turbines as the number of turbines in the farm is varied. An enabling ingredient to perform this analysis is a dynamic reduced-order aggregate model for a wind farm that preserves the model order and structure of individual wind turbines. This facilitates stability analysis since the number of wind turbines can be varied with ease and small-signal stability of the mixed machine and inverter-interfaced turbines can be examined systematically. Although there is a vast body of literature on small-signal stability of wind farms, penetration level of wind farms is significantly less studied in this context; this paper introduces a systematic approach for such an analysis. Case studies for a modified Kundur two-area system with an integrated wind farm indicate that as the number of wind turbines is increased to a point that the penetration level is approximately 25%, there is a loss of small-signal stability. We validate this with time-domain simulations for the nonlinear system dynamics and also propose a redesign strategy grounded in a system-theoretic analysis of the dynamical models.
“Let’s Bid!” - A modular activity to promote interest in engineering economy

This article presents a modular activity designed to promote interest and understanding of engineering economics concepts in a complex environment. Through a competition game, called “Let’s Bid!”, ...
Fluoroquinolone prophylaxis does not increase risk of neuropathy in children with acute lymphoblastic leukemia.

Background Fluoroquinolone antibiotics are frequently utilized in pediatric oncology patients as prophylaxis or step-down therapy following broad spectrum beta-lactam therapy for febrile neutropenia. Concerns regarding neurotoxicity limit the use of these agents. No studies have evaluated the association between fluoroquinolone use and neurotoxicity in pediatric oncology patients receiving other neurotoxic agents such as vincristine. Methods An observational cohort study comprising patients aged 0-18 at diagnosis enrolled on a prospective study for treatment of acute lymphoblastic leukemia (ALL) at a pediatric comprehensive cancer center between October 2007 and November 2018. Data for neuropathic pain and sensory or motor neuropathy were collected prospectively, and a Cox proportional hazards regression model was used to evaluate associations between administration of fluoroquinolone antibiotics during induction therapy and subsequent development of vincristine-induced peripheral neurotoxicity (VIPN). Results A total of 598 participants were enrolled, including 338 (57%) who received fluoroquinolones during induction therapy; of these 470 (79%) were diagnosed with VIPN and 139 (23%) were diagnosed with high-grade (Grade 3+) VIPN. On unadjusted analyses, and analyses adjusted for age and race, there was no evidence of an association between fluoroquinolone exposure and subsequent VIPN (hazard ratio [HR] 0.8, 95% CI 0.5-1.04, P = .08) or high-grade VIPN (HR 1.1, 95% CI 0.4-2.2, P = .87). Conclusions The results of this observational study do not show an association between exposure to fluoroquinolone antibiotics during induction therapy for ALL and subsequent development of vincristine-induced peripheral neuropathies, and suggest that a large increase in VIPN is unlikely.
Lumbosacral paraspinal interfascial plane blocks for pain control after feminizing genital gender affirmation surgery

Aim: Feminizing genital gender affirmation surgery (fgGAS) is increasing in prevalence in the USA. Management of postoperative pain following fgGAS is challenging. We report a series of patients where post-fgGAS pain was adequately controlled with paraspinal blocks. Materials & methods: This is a case series of three patients who received bilateral lumbar and sacral erector spinae plane blocks after fgGAS. Block techniques, medications administered, opioid requirements and pain scores were reviewed. Results: Erector spinae plane blocks provided adequate analgesia for 24-48 h following the block. Conclusion: Currently, there are two regional anesthetic techniques described for the treatment of postoperative pain after fgGAS. We describe two additional approaches as options for improved pain management in this patient population.
The IFRS Adoption Reform Through the Lens of Neo-Institutionalism: The Case of the Russian Federation

The study examines the impact of IFRS adoption and concurrent regulatory reforms on the reporting quality of Russian public firms. Unlike much of prior literature focusing on the economic and legal explanations to the IFRS adoption, we build on the neo-institutional theory of DiMaggio and Powell (1983, 1991). We show that changes in reporting quality, as measured by value relevance of information and the degree of conditional conservatism, are a function of the type of the isomorphic pressure within a country. We find that firms that experienced coercive, mimetic and normative societal pressures - those that both adopted IFRS and were affected by other regulatory reforms - experienced significant improvements in reporting quality. We do not find such evidence for firms that experienced only coercive pressure - those that were affected by changes in regulations but were exempt from the IFRS reporting requirement. Overall, the study sheds light on complexity of the interplay between external pressures and a wide array of internal pressures on public firms to adopt IFRS. Notably, the study’s unique research settings also allow us to achieve a better identification strategy, compared to prior IFRS studies that attempted to disentangle the IFRS adoption and regulations/enforcement effects. Our findings indicate that the incremental “IFRS adoption” effect on reporting quality was significantly positive, whereas the individual “regulations” effect was non-detectable.
Optimal EV Charger Level Specification for Residential Buildings with Renewable Energy

Electric Vehicles (EVs) have witnessed high interest lately due to different environmental, socio-political, and economic factors. The chargers of EVs are categorized into three levels; L1 and L2. These chargers have different power ratings and prices. On the other hand, many houses started to add distributed energy resources such as photovoltaic (PV) to their existing power service. This paper investigates the optimal level of an EV charger for a residential building with renewable energy. The optimization aims to reduce the energy cost during the lifetime of the EV battery. The optimization constraints include the EV state of charge, the charging/discharging power limits of the EV, the EV expected availability, the house service size, and the EV maximum number of cycles. The study also investigates the feasibility of conducting a power service upgrade while keeping a power reserve for future load uncertainty. The problem is formulated as a non-convex optimization problem utilizing the Gurobi solver. The optimization problem is solved for different scenarios presenting different loads, PV power, and EV availability scenarios. Case studies are conducted using household data in Los Angeles, CA. The studies evaluated the energy cost saving for different levels of the chargers in the case of various PV sizes and energy tariffs. This research is a collaboration result between three commonwealth campuses in Pennsylvania State University.
Fuzzy Hierarchical Evaluation and Decision Making (Fuzzy-HEDM)

Bei der Diskussion von Methoden des„fuzzy multiple objective decision making“ (Kapitel 6) und des„fuzzy multiple attribute decision making“ (Kapitel 7) wurde die gleichzeitige Verfolgung mehrerer Zielsetzungen und die damit zusammenhangende Problematik diskutiert. Dabei wurden die in den Planungs- bzw. Entscheidungssystemen verfolgten Ziele innerhalb eines einstufigen Zielsystems betrachtet, d.h., alle formulierten Ziele wurden — wenn auch unterschiedlich gewichtet — gleichberechtigt behandelt. Daneben existieren jedoch Problemsituationen, in denen ein Zielsystem sinnvollerweise zunachst durch die Bildung einer Zielhierarchie operationalisiert werden mus, um zu bewertbaren Kriterien zu gelangen.
Evisceration with Hydroxyapatite Implant: Surgical Technique and Review of 31 Case Reports

Purpose: To evaluate the use of hydroxyapatite (HA) as an orbital implant with evisceration. Background: Although several reports have documented good success with HA orbital implants and their use with enucleation, only a few reports mention HA with evisceration. These few reports are less favorable, with exposure rates as high as 67%. In contrast, the authors have had good success with evisceration and HA implants with no major complications and a low exposure rate. Methods: A retrospective analysis of all eviscerations with HA implant performed between January 1989 and July 1993 was completed (n = 31). Patients underwent evisceration with scleral modification, including anterior relaxing incisions and posterior sclerotomies to accommodate a large sphere without tension on the wound. Patient records were reviewed for demographic data, surgical indication, sphere size, clinical outcome, complications, and follow-up interval. The surgical technique is described. Results: All 31 patients underwent successful surgery with complications limited to exposure (6%), mild superior sulcus deficit (6%), and a conjunctival cyst (3%). No patient required further socket reconstruction, and no patient required peg placement to enhance motility. The average follow-up interval was 13.3 months. Conclusions: The authors have had good success using HA orbital implants for evisceration without major complications. Primary evisceration with HA implantation after posterior sclerotomies is a safe and effective method for treating patients with a blind, painful eye.
Spectral Theory of Linear Control and Estimation Problems

Consider the finite-dimensional discrete-time linear system $$x\left( {k + 1} \right) = A\;x\left( k \right) + B\;u\left( k \right),\;x\left( i \right) = \xi $$ (1) where x(k) e R and u(k) ϵ Rr; A and B are time-invariant matrices of compatible size. The pair (A, B) is assumed to be controllable and A is asymptotically stable (by feedback invariance [4], this restriction does not introduce any loss of generality here). Together with (1), define the quadratic cost $$J\left[ {\xi ,U\left( {i,t} \right)} \right] = \sum\limits_{k = 1}^{t - 1} {\left[ {x'\left( k \right)Qx\left( k \right) + 2x'\left( k \right)Su\left( k \right) + u'\left( k \right)Ru\left( k \right)} \right]} $$ (2) where U(i, t) = [u’(i) u’(i + 1) ... u’(t-1)]’ and ξ = x(i) . The overall weighting matrix\(W = \left[ {\begin{array}{*{20}{c}} Q \\ {S'} \\ \end{array} \quad \begin{array}{*{20}{c}} S \\ R \\ \end{array} } \right]\) is symmetric, but not necessarily positive semi-definite.
Variable-rate pipelined multiplier design for reconfigurable DSP applications

This paper presents a VLSI design and implementation of a variable-rate multiply-and-accumulate (MAC) block for DSP applications. The pipeline depth of the multiplier is dynamically controlled given the throughput requirement of the application. The depth of pipeline varies at the hardware level which controls the rate of execution to save power consumption. The MAC is targeted for a coarse grain FPGA design to support a wide range of digital signal processing applications. The power consumption is lowered by reducing the unnecessary register switching. The technique is applied to carry-save and Booth recoded multipliers. The MAC circuit is designed in 0.35-/spl mu/m CMOS processing technology and evaluated for current DSP applications.
Modeling and simulation of routing protocol for mobile ad hoc networks using colored petri nets

In a mobile ad hoc network (MANET), mobile nodes directly send messages to each other via wireless transmission. A node can send a message to a destination node beyond its transmission range by using other nodes as relay points, and thus a node can function as a router. Typical applications of MANETs include defense systems such as battlefield survivability, and disaster recovery. The research on MANETs originates from part of the Advanced Research Projects Agency (ARPA) project in the 1970s. With the explosive growth of the Internet and mobile communication networks, challenging requirements have been introduced into MANETs and designing routing protocols has become more complex. For a successful application of MANETs, it is very important to ensure that a routing protocol is unambiguous, complete and functionally correct. One approach to ensuring correctness of an existing routing protocol is to create a formal model for the protocol, and analyze the model to determine if indeed the protocol provides the defined service correctly. Colored Petri Nets (CPNs) are a suitable modeling language for this purpose, as it can conveniently express non-determinism, concurrency and different levels of abstraction that are inherent in routing protocols. However, it is not easy to build a CPN model of a MANET because a node can move in and out of its transmission range and thus the MANET's topology (graph) dynamically changes. In this paper, we proposes a topology approximation (TA) mechanism to address this problem of mobility and perform simulations of a typical routing protocol called Ad Hoc On-Demand Distance Vector Routing (AODV). Our simulation results show that our proposed TA mechanism can indeed mimic the dynamically changing graph (mobility) of a MANET.
Transnational Politics, International Relations Theory, and Human Rights

century presents a puzzle for students of comparative politics and international relations. Many of our dominant theories-realism, rational choice, and economic interest group theories-have trouble accounting for the rise of human rights politics except to dismiss them as marginal, insignificant, or an ideological cover beneath which economic groups or hegemonic countries pursue their interests. But as the other essays here and the daily newspapers make abundantly clear, human rights issues are not marginal, and increasingly detailed policy and institutional mechanisms exist to ensure the implementation of international human rights standards. In some cases, these policies can have a direct impact on human rights practices, and have contributed to reduced repression and regime changes (see Sikkink 1993; Risse, Ropp, and Sikkink forthcoming).
Anti-hapten antibody induction with deoxyribonucleic acid carrier

Abstract An immunogen was prepared by substituting 2,4,6-trinitrophenyl groups to deoxyguanosine residues in chemically pure DNA. Isolation of antibodies to the haptenic group suggests that DNA can serve as a carrier.
Mechanistic study of the acid catalyzed formation and hydrolysis of MTBE in nonpolar media

The acid catalyzed hydrolysis of MTBE using p-toluenesulfonic acid was studied in nonpolar medium to ascertain the effect of nucleophile upon reaction. NMR measurements showed protonation of both MTBE and methanol by p-toluenesulfonic acid in nonpolar medium but no nucleophile-electrophile interaction of MTBE with p-toluenesulfonic acid methyl ester as potential nucleophile. Addition or in situ generation of a nucleophile did not accelerate the reaction. At low conversions and low catalyst concentration the reaction exhibited pseudo zero order with respect to reactant concentration and second order with respect to catalyst concentration. The results suggest protonation of MTBE in a fast preequilibrium step in which the acid catalyst exhibits cooperative effect. No nucleophilic assistance in the transition state of MTBE hydrolysis in nonpolar medium occurs.
Interaction of the Galilean Moons with their plasma environments

Abstract The Galilean moons, especially Io, affect not just their local environment but also the Jovian ionosphere at the ends of the flux tubes connected to the moons. Moreover, the mass added to the magnetosphere by Io affects much of the rest of the magnetosphere. The magnetosphere is energized by this mass-loading, powering the aurora, accelerating radiation belt particles, and generating radio emissions. This review examines how the mass-loading affects the magnetosphere and ionosphere; the differences in the interactions of Io, Europa, Ganymede and Callisto; and some of the kinetic phenomena associated with the interaction.
An efficient method to express and refold a truncated human procaspase-9: a caspase with activity toward Glu-X bonds.

Abstract A truncated form of human procaspase-9 missing the first 111 amino acids, and a variety of mutants derived therefrom, have been expressed in Escherichia coli inclusion bodies. Upon refolding to active enzymes, Δ(1–111) procaspase-9 and mutants were recovered at purity greater than 95% and with a final yield of 20-35 mg/L cell culture. Our active procaspase-9 retains its pro-segment, while undergoing major auto processing at Asp 315 and a minor (20%) cleavage at Glu 306 . This unusual cleavage at a Glu-X bond also took place in the D315E mutant, and we describe herein the inhibitor Z-VAE-fmk that shows enhanced inactivation of procaspase-9 over caspases-3. The bond at Asp 330 , not processed by procaspase-9, is cleaved by caspase-3 and the resulting procaspase-9 variant, missing the 316–330 bridge, is six times as active as the non-mutated Δ(1–111) proenzyme. A deletion mutant lacking residues 316–330 underwent auto activation by cleavage at Asp 315 -Ala 331 bond. Moreover, substitution of Glu 306 by an Asp residue in this mutant led to rapid removal of the peptide spanning Ser 307 to Asp 330 , and resulted in an enzyme that was 7.6 times as active as the non-mutated Δ(1–111) procaspase-9. Finally, replacing both Asp315 and Glu306 with Ala generated a procaspase-9 mutant incapable of auto processing. This single chain procaspase-9 was fully as active as the non-mutated Δ(1–111) enzyme processed at Asp 315 or Glu 306 . Our demonstration that unprocessed procaspase-9 mutants are active as proteases with caspase-type specificity suggests that the role of procaspase-9 in cascade activation of executioner caspases might, in some circumstances, be carried out alone and without association of the apoptosome.
Influence of estrogen status on endosseous implant osseointegration.

Abstract Purpose: This retrospective study tested the hypothesis that postmenopausal women have lower rates of osseointegration of endosseous implants than premenopausal women and male controls. The role of estrogen replacement therapy (ERT) was also evaluated. Patients and Methods: Review of medical records allowed identification of patients who had received endosseous implants. Patients with concurrent illness, a smoking or ethanol use history, or metabolic bone disease were excluded. Five groups of subjects were identified: 1) 168 postmenopausal women without ERT; 2) 75 postmenopausal women supplemented with ERT; 3) 114 premenopausal women; 4) 59 men younger than 50 years; and 5) 110 men older than 50 years. Successful osseointegration was defined as stability at uncovering using a manual torque wrench and was confirmed radiographically. Failure rate comparisons were made between groups using both Fisher's exact tests and Poisson regression models. Results: Postmenopausal women without ERT had the highest maxillary failure rate (13.6%) which was significantly greater than for premenopausal women (6.3%, P =.039) and for men older than 50 (7.6%, P =.051). Although the maxillary failure rate of unsupplemented postmenopausal women was greater than for ERT supplemented women (8.1%), the comparison did not reach statistical significance (P =.17). The maxillary failure rate was similar between men younger than 50 years and those older than 50 years (6.3 vs 7.6%, not significant) Mandibular implant failures in all groups showed no statistically significant differences. Conclusion: The effect of postmenopausal estrogen status on compromised implant healing was shown in the maxilla but not in the mandible. Unsupplemented postmenopausal women had the highest failure rate. Although a statistical difference was not achieved, ERT reduced the maxillary failure rate by 41%. These results suggest that estrogen deficiency and the resultant bony changes associated with menopause may be risk factors for endosseous implant failure in the maxilla. © 2001 American Association of Oral and Maxillofacial Surgeons
The cultural significance of dress and textiles

Renne, Elisha P. Cloth that Does not Die: The Meaning of Cloth in Bunu Social Life. Seattle: University of Washington Press, 1995. xxi + 269 pp. including appendix, notes, glossary, bibliography, and index. $40.00 cloth. Hendrickson, Carol. Weaving Identities: Construction of Dress and Self in a Highland Guatemala Town. Austin: University of Texas Press, 1993. xiv + 295 pp. including notes, bibliography, and index. $35.00 cloth, $15.95 paper. Schevill, Margot Blum. Maya Textiles of Guatemala. Austin: University of Texas Press, 1992. xiii + 295 pp. including notes, bibliography, and indices. $65.00 cloth, $29.95 paper.
Acid—base titrations in aqueous micellar systems

Some water-insoluble carboxylic acids and amines have been titrated in aqueous surfactant solutions to demonstrate that solubilization in micelles provides a useful solvent system for certain acid—base titrations. Potentiometric titrations can be very slow because of electrode drift in these solutions, but visual titrations are convenient. Observed pK shifts are generally interpretable in terms of the influence of micellar charge on the work of proton removal.
Ab initio calculations and molecular mechanics (MM3) force field development for sulfonamide and its alkyl derivatives

Abstract Sulfonamide and eight of its alkyl derivatives were studied with ab initio calculations ( gaussian 94) at the MP2/6–31 + G∗ level of theory. Based on the theoretically calculated geometries and vibrational spectra, and on torsional energy profiles, MM3 force field parameters have been developed that accurately simulate the behavior of this class of compound. The Parameter Analysis and Refinement Toolkit System (PARTS) has been shown to provide a convenient approach for molecular mechanics parameterization and is used in this study to quickly generate MM3 parameters. Using this new set of parameters, MM3 reproduces well the ab initio results for all nine molecules within the training set in terms of both geometrical data and vibrational frequencies.
A theoretical analysis of hemodynamic and biomechanical alterations in intracranial AVMs after radiosurgery

Abstract Purpose : Stereotactic radiosurgery is being increasingly used to treat intracranial arteriovenous malformations (AVMs). However, successful radiosurgery may involve latent periods of 1–2 years prior to AVM obliteration. This latent period include states of altered flow patterns that may or may not influence hemorrhage probabilities. The probability of hemorrhage is likely to be related to the degree of biomechanical stress across the AVM shunt walls. This paper describes a theoretical analysis of the altered hemodynamics and biomechanical stresses within AVM shunts post-radiosurgery. Methods and Materials : The mathematical model is comprised of linked flow compartments that represent the AVM and adjacent normal vasculature. As obliteration of the irradiated shunts occur, changes in flow rates and pressure gradients are calculated based on first order fluid dynamics. Stress on the AVM shunt walls is calculated based on tangential forces due to intramural pressure. Two basic models are presented: a distribution of shunts with fixed thin walls subject to step-function obliteration (Model 1), and a distribution of shunts subject to luminal obliteration from slowly thickening walls (Model II). Variations on these models are analyzed, including sequential, selective and random shunt obliteration, and uniform or Poisson distributions of shunt radii. Results : Model I reveals that the range of pressure alterations in the radiosurgically-treated AVM include the possibility of transient increases in the total biomechanical stress within the shunt walls prior to obliteration. Model II demonstrates that uniform luminal narrowing via thickened walls should lead to reduced transmural stresses. The precise temporal pattern of AVM flow decrease and biomechanical stress reduction depends on the selection of shunts that are obliterated. Conclusion : (a) The hemodynamic and biomechanical changes appear to be relatively independent of the shunt distribution but highly dependent on the temporal pattern of the obliterative process, (b) uniformly thickened shunt walls should uniformly decrease biomechanical stresses in the latent period prior to complete obliteration, but if uniform obliteration is not achieved, (c) transient alterations in pressure versus stress relationships may lead to temporarily increased biomechanical stress prior to complete obliteration, and (d) reduction in stress may not reach significant levels until the AVM is almost completely obliterated.
Far-red tracer analysis of traumatic cerebrovascular permeability

Abstract Background Blood brain barrier (BBB) compromise is a key pathophysiological component of secondary traumatic brain injury characterized by edema and neuroinflammation in a previously immune-privileged environment. Current assays for BBB permeability are limited by working size, harsh extraction processes, suboptimal detection via absorbance, and wide excitation fluorescence spectra. In this study, we evaluate the feasibility of Alexa Fluor 680, a far-red dye bioconjugated to dextran, as an alternative assay to improve resolution and sensitivity. Methods Alexa Fluor was introduced intravenously on the day of sacrifice to three groups: sham, controlled cortical impact (CCI), and CCI treated with a cell based therapy known to reduce BBB permeability. The brains were sectioned coronally and imaged using an infrared laser scanner to generate intensity plot profiles as well as signal threshold images to distinguish regions with varying degrees of permeability. Results Linear plot profile analysis demonstrated greater signal intensity from CCI than treated rats at corresponding injury depths. Threshold analysis identified rims of signal at low + narrow threshold ranges. The integrated signals from a treatment group known to preserve the BBB were significantly less than the groups with CCI injury alone. There was no significant difference at high + wide signal intensity threshold ranges. Conclusions Alexa Fluor 680 infrared photodetection and image analysis can aid in detecting differential degrees of BBB permeability after traumatic brain injury and maybe particularly useful in demonstrating BBB preservation of at-risk regions in response to therapeutic agents.
A facile route to trans cyclic carbonates of sugars

Abstract Five-membered, cyclic carbonates are formed when vicinal trans -hydroxyl groups in D -glucopyranosides are treated with ethyl chloroformate in the presence of triethylamine. With these reagents, methyl 4,6- O -benzylidene-α- D -glucopyranoside 2,3-carbonate ( 2 ), methyl 2,6-di- O -(methylsulfonyl)-α- D -glucopyranoside 3,4-carbonate ( 5 ), and methyl 4- O -(ethoxycarbonyl)-6- O -( p -tolylsulfonyl)-α- D -glucopyranoside 2,3-carbonate ( 8 ) were prepared. In contrast, when pyridine is the base present, only acyclic carbonates are formed.
Biology of Lasconotus subcostulatus (Coleoptera: Colydiidae) with Special Reference to Feeding Behavior

Lasconotus subcostulatus Kraus is an associate of several species of bark beetles. They enter the galleries of Ips paraconfusus (LeConte) and oviposit in concealed sites. The incubation period lasts 3-4 days. Larvae usually feed upon fungi until they reach the third stage. The third instar is very aggressive and wide ranging in its feeding habits. It burrows through almost all of the frass-filled galleries, killing and eating any Ips larvae or unpigmented pupae encountered. First and second instars of Lasconotus will, however, switch their diet from fungi to Ips larvae if the larvae have been immobilized. This study indicates there are 4 larval stadia in the life cycle. Egg to adult takes 31-40 days.
What radio and TV managers want in the broadcast curriculum

This article reports the findings of a national survey of radio managers and TV managers concerning what they consider essential elements for the college broadcast curriculum. Managers see present curricula as unrealistically designed for training commercial broadcasters. Especially lacking are adequate training in production, sales, and the business aspects of broadcasting. The article offers suggestions to educators who want to develop curricula that meet the needs of commercial broadcasting, as seen by top management.
Phase-locking of a harmonically forced self-oscillating system

Abstract We present the bifurcation diagram for solutions of the forced Landau equation [ d d t −1 + iω + (1 + ic 3 )|ψ| 2 ]ψ = F 0 , for c3 ≠ 0. The bifurcations of the phase locked states (fixed points) are obtained analytically for all parameter values. Bistable regions exist in the bifurcation diagram consisting of phase locked solutions alone as well as a phase locked and a periodic solution, sometimes accompanied by a repelling closed orbit.
Trunk movements during locomotion in the marsupial Monodelphis domestica (didelphidae)

The small didelphid cmarsupial, Monodelphis domestica, uses a lateral sequence walk during slow treadmill locomotion and gradually shifts to a trot as speed increases. At higher speeds it changes abruptly to a half-bound. Cinematographic records suggest significant lateral bending but no sagittal bending of the trunk during the slow walk and a reduced amount of lateral bending during the fast walk. There is slight lteral, but no sagittal, bending during the trot. Sagittal bending is obvious during the half-bound, but no lateral bending is evident. Cineradiography confirms that the vertebral column of the trunk bends laterally during the slow walk. Bending occurs throughout the trunk region, but seems to be most pronounced in the anterior lumbar region. Associated with this bending of the trunk is substantial rotation of the pelvic girdle in the plane of yaw. Pelvic rotation is synchronized with the locomotor cycle of hindlimbs. Each side of the pelvis rotates forward during the recovery phase of the ipsilateral hindlimb and backward during the contact phase of this limb. Information on locomotor trunk movements in other limbed tetrapods is limited. The pattern of trunk bending found in Monodelphis, however, is consistent with that reported in the placental mammal Felis catus and in some lepidosaurian reptiles. This suggests that sagittal bending did not replace lateral bending during the evolution of mammals, as is sometimes suggested. Rather, bending in the vertical plane seems to have been added to lateral bleeding when the ancestors of extant mammals acquired galloping and bounding capabilities.
A new technique for calculating toroidal harmonic coefficients for curl-free magnetic fields in helical toroidal devices

Abstract In a curl-free toroidal magnetic system, the vector magnetic field may be derived from a scalar magnetic potential expressed as a series of toroidal harmonic functions. A new method of computing the coefficients of the toroidal harmonics of the magnetic scalar potential is presented in this paper. The method uses Fourier integrals performed over the poloidal and toroidal angles on a closed surface. The integrand includes the component of the magnetic field normal to the toroidal surface and a multiplying factor chosen to create a set of simple equations which are linear in the coefficients. This set of equations is then inverted to obtain the toroidal harmonic coefficients. The magnetic fields calculated using the magnetic scalar potential with these coefficients are found to agree well with the original magnetic field even for a small number of coefficients. For a small number of coefficients used in the scalar potential, the time required to calculate the magnetic field is reduced by up to a factor of five from standard Biot-Savart methods.