cssi/SciSciGPT-SciSciNet huggingface dataset:
Sources of the Nucleotide Pools in Escherichia coli after Infection with Bacteriophage T2

Abstract It has long been known that infection of Escherichia coli with bacteriophage T2 causes degradation of bacterial deoxyribonucleic acid and that 70 to 80% of the degradation products appear in viral DNA within 30 min after infection. It is reasonable to assume that exonucleases participate in this process and catalyze the production of mononucleotide intermediates. To study this system in more detail, the amounts of free mononucleotides present in the cells were measured at various times after infection with phage T2. The extent of transferal of labeled nucleotides from bacterial nucleic acids to the free mononucleotide pools was also studied. Only a gradual and small increase in the total amounts of deoxyribonucleotides in the pools was observed after infection, in spite of drastic changes both in the rate of nucleic acid synthesis and in the pathways of nucleic acid metabolism that occur at this time. This suggests that the intracellular concentrations of these intermediates are precisely controlled. By labeling the bacterial nucleic acid with 32P-orthophosphate and subsequently infecting the cells with T2 phage, the amount of nucleic acid-derived nucleotides present in the deoxyribonucleotide pools was found to increase rapidly 4 min after infection and decline precipitously 10 to 15 min after infection. At 7 to 8 min after infection, 50 to 75% of the nucleotides entering these pools came from the bacterial nucleic acids. Of the known bacterial and phage-induced exonucleases, only T2 exonuclease A exhibits sufficient activity in vitro to readily account for the rate of nucleotide production that is observed. The time of appearance of this enzymatic activity is correlated with the time of increase of nucleic acid-derived nucleotides in the pools. It is paradoxical that, 10 to 15 min after infection, a rapid decline of labeling of the pools occurs at a time when half of the bacterial DNA remains. Knowledge of the relative specific activities of the deoxycytidylate and thymidylate pools makes it possible to estimate the rate of their interconversion in vivo by the pathway involving the phage-induced enzymes deoxycytidylate deaminase and thymidylate synthetase. The data indicate that, at 9 min after infection, approximately 15% of the deoxycytidylate derived from bacterial DNA is converted to thymidylate via this pathway. The high specific activity of the deoxyadenylate pool suggests that some of this compound may have been derived from a deoxyguanosine nucleotide. A small but reproducibly measurable amount of nucleic acid-derived phosphate was found in the nucleotide pools of uninfected cells. This suggests that a slow turnover of "stable" ribonucleic acid, or perhaps both RNA and DNA, occurs in rapidly growing E. coli.
On Learning Regular Expressions and Patterns Via Membership and Correction Queries

Based on the ideas suggested in [5], the following model for learning from a variant of correctionqueries to an oracle is proposed: being asked a membership query, the oracle, in the case of negative answer, returns also a correction--- a positive datum (that has not been seen in the learning process yet) with the smallest edit distance from the queried string. Polynomial-time algorithms for learning a class of regular expressions from one such query and membership queries and learning pattern languages from queries of this type are proposed and discussed.
Scheduling uplink bandwidth in application-layer multicast trees

Many applications can benefit from the use of multicast to distribute content efficiently. Due to the limited deployment of network-layer multicast, several application-layer multicast schemes have been proposed. In these schemes, the nodes in the multicast tree are end systems which are typically connected to the network by a single access link. Transmissions to the children of a node in the multicast tree have to share this single uplink, a factor largely ignored by previous work. In this work, we examine the effect of access link scheduling on the latency of content delivery in a multicast tree. Specifically, we examine the general case where multiple packets (comprising a block of data) are sent to each child in turn. We provide an analytical relation to compute the latency at a node in the multicast tree and show the relationship to the packet size and block size used to transfer data. We propose heuristics for tree construction which take link serialization into account. We evaluate this effect using simulations and show that using larger block sizes to transfer data can reduce the average finish time of the nodes in the multicast tree at the expense of slightly increased variance.
Initiation of a mesoscale convective complex over the Ethiopian Highlands preceding the genesis of Hurricane Alberto (2000)

[1] A tropical disturbance, which would later become Hurricane Alberto (2000), was traced back in time as a mesoscale convective complex (MCC) to the Ethiopian Highlands (EH), where the MCC first developed. Meteosat-7 imagery indicates that the MCC develops during the late afternoon and evening of 28 July 2000, and that a mesovortex (MV) was evident on the morning of 29 July 2000. A preliminary mesoscale model simulation features the development of two areas of maximum relative vorticity in the middle troposphere, with the maturation of one of the vorticity maxima into a significant MV. The higher-level vorticity center of the simulated MV tracks westward and is nearly collocated with the vortex signature in satellite imagery, while the lower-level center remains near the lee side of the EH. The vortex signature in satellite imagery was traceable to the cyclogenesis stage over the eastern Atlantic Ocean.
Postfertilization growth of microvilli in the sea urchin egg: New views from eggs that have been quick-frozen, freeze-fractured, and deeply etched

Abstract We have used quick-freezing, freeze-fracture, and deep etching to study postfertilization growth of microvilli in the sea urchin, Strongylocentrotus purpuratus . Between 1 and 2 min postinsemination, we observed rapid growth of numerous finger-like microvilli to about 0.7 μm in length. Subsequently, groups of two to four microvilli became raised off the egg surface on broad cytoplasmic bases. Finally, by 5 min postinsemination, these bases had become interconnected by thin sheets of cytoplasm to form a continuous network of ruffles across the egg surface. Corresponding thin sections of quick-frozen and freeze-substituted eggs showed that these microvilli contained networks of microfilaments. The finger-like processes had bundles of parallel microfilaments that ran their entire length, while the ruffles of cytoplasm contained sheets of crisscrossed microfilaments. These observations support the hypothesis that microvillar growth results from formation of new microfilament networks.
Factors That Control Successful Entropically Driven Chiral Separations in SFC and HPLC.

With temperature increases, selectivity of chiral separations decreases until enantiomers coelute at an isoelution temperature. Above this temperature, elution order should reverse and selectivity will increase with temperature. In this region, separation is termed “entropically driven”. Entropically driven chiral separations hold the promise of being able to concurrently increase selectivity and column efficiency by means of increased temperature. The ability to achieve such separations is hindered by high isoelution temperatures. The isoelution temperature is determined by a balance of enthalpic and entropic contributions. A variety of mobile phase modifiers are evaluated for their ability to moderate these contributions. Results suggest that more use should be made of non-alcohol modifiers. The major barrier to entropically driven separations was found to be the nonspecific retention increase that is characteristic when the critical temperature is traversed. Use of hexane in place of CO2 shifts the pos...
Generation and cycloadditions of hydroxy(and trimethylsiloxy)phenylethynylketene

Abstract An unusual rearrangement of 5,6-dihydroxy-1,3-dimethoxy-5,6-diphenylethynyl-1,3-cyclohexadiene ( 1 ) to 7-hydroxy-1,4-dimethoxy-2-phenylethynylbicyclo[2.2.2]octadiene-8-one ( 2a ) was observed when I was treated with ZnCl 2 in refluxing carbon tetrachloride. The bicyclooctadienones 2a,b were observed to undergo retro Diels-Alder fragmentation at 138 °C to give hydroxy(or trimethylsiloxy)-phenylethynylketenes 3a,b , the only examples of alkynylketenes other than alkynylcyanoketenes to appear in the literature. 1 The ketene 3 b cycloadds to a variety of ketenophiles, but most interestingly, it undergoes unusual reactions with diphenylacetylene to give the cyclopentenedione 7 and with ethoxypropyne to yield the highly functionalized benzocfuinone 8 .
Effects of the Use of Visual Strategies in Play Groups for Children with Autism Spectrum Disorders and their Peers

The purpose of this study was to investigate the impact of visual strategies with preschool children with autism spectrum disorders (ASD) and their peers during play group sessions. A changing-criterion design was implemented with three preschool-aged children with ASD while they participated in play groups with four typically-developing peers. Results indicated improvements in the use of script phrases, context-related comments, and intervals in which speech occurred for all three participants. Results regarding unscripted phrases, responses, and use of prompts were variable and are discussed.
Safety considerations for small Unmanned Aerial Systems with distributed users

This paper identifies three categories of safety risks posed by allowing multiple users to engage with small Unmanned Aerial Systems (sUAS) and offers five recommendations on how to reduce or mitigate these vulnerabilities. Data from sUAS can benefit multiple experts at a disaster who may not be familiar with robots or colocated with the pilot. Two different styles of interfaces have been developed and tested with responders conducting exercises to facilitate team coordination with a quadrotor at Texas AM use artificial intelligence to resolve conflicts between competing directives from multiple experts; allow the pilot, or a software agent, to turn off the expert's ability to control or communication; use multi-modal warnings rather than rely on visual cues; and add guarded motion to prevent collisions.
Comprehensive Evaluation of Peripheral Nerve Regeneration in the Acute Healing Phase Using Tissue Clearing and Optical Microscopy in a Rodent Model

Peripheral nerve injury (PNI), a common injury in both the civilian and military arenas, is usually associated with high healthcare costs and with patients enduring slow recovery times, diminished quality of life, and potential long-term disability. Patients with PNI typically undergo complex interventions but the factors that govern optimal response are not fully characterized. A fundamental understanding of the cellular and tissue-level events in the immediate postoperative period is essential for improving treatment and optimizing repair. Here, we demonstrate a comprehensive imaging approach to evaluate peripheral nerve axonal regeneration in a rodent PNI model using a tissue clearing method to improve depth penetration while preserving neural architecture. Sciatic nerve transaction and end-to-end repair were performed in both wild type and thy-1 GFP rats. The nerves were harvested at time points after repair before undergoing whole mount immunofluorescence staining and tissue clearing. By increasing the optic depth penetration, tissue clearing allowed the visualization and evaluation of Wallerian degeneration and nerve regrowth throughout entire sciatic nerves with subcellular resolution. The tissue clearing protocol did not affect immunofluorescence labeling and no observable decrease in the fluorescence signal was observed. Large-area, high-resolution tissue volumes could be quantified to provide structural and connectivity information not available from current gold-standard approaches for evaluating axonal regeneration following PNI. The results are suggestive of observed behavioral recovery in vivo after neurorrhaphy, providing a method of evaluating axonal regeneration following repair that can serve as an adjunct to current standard outcomes measurements. This study demonstrates that tissue clearing following whole mount immunofluorescence staining enables the complete visualization and quantitative evaluation of axons throughout nerves in a PNI model. The methods developed in this study could advance PNI research allowing both researchers and clinicians to further understand the individual events of axonal degeneration and regeneration on a multifaceted level.
Characters of irreducible Harish-Chandra modules and Goldie ranks of their annihilators

Assume that GC is a simply connected complex semi-simple Lie group with Lie algebra [unk]. Let G ⊂ GC be a real form, H ⊂ G be a maximally split Cartan subgroup with Lie algebra [unk]0, [unk] = [unk]0 [unk] C, and P ⊆ [unk]* be the weight lattice. If X is an irreducible Harish-Chandra module with infinitesimal character λ ∈ [unk]*, one can associate to X a family {θ(μ): μ ∈ λ + P} of Z-linear combinations of distribution characters of G, so that θ(λ) = X. θ(μ) is irreducible when μ lies in Cλ, a certain positive “Weyl” chamber containing λ. In this case let Ann θ(μ) be its annihilator in U([unk]) and set p(μ) = Goldie rank of U([unk])/ Ann θ(μ). Let d = Gelfand-Kirillov dimension of X. For most x ∈ [unk]0 if exp tx is regular for small t > 0 then (i) c(μ) = limt→0+td θ(μ) (exp tx) exists for all μ ∈ λ + P; (ii) c(μ) extends to a homogeneous Weyl group harmonic polynomial on [unk]* of degree ½(dim G - dim H) - d; (iii) up to a constant, c = the polynomial extending p to [unk]*. c is said to be the character polynomial of Ann X.
Invested loyalty: the impact of ubiquitous technology on the current loyalty paradigm and the potential revolution

Regarding communication and information technology advance as an impetus that may manipulate even human cognitive process, this study addresses the possibly diminishing hegemony of expectation confirmation process. With sophisticated interactive communication devices, providing virtual experiences, consumers no longer need to undergo the actual contacts with products and services to settle down in relationships because the experiences through ubiquitous technology are near reality. Once customers become able to invest their knowledge and values in the relationships with firms by means of ubiquitous technology that substantiates sensability, outsourceability, and coproduction facilitation, they will start building relational values, such as satisfaction, trust, and commitment. These relational values are expected to lead consumers to a new form of loyalty called invested loyalty. Consequently, plenty of managerial implications and research opportunities are identified. Firms utilizing ubiquitous technology...
Cell surface F1Fo ATP synthase: A new paradigm?

The mitochondrial F1Fo adenosine triphosphate (ATP) synthase is one of the most thoroughly studied enzyme complexes known. Yet, a number of new observations suggesting that the enzyme is also located on the cell surface necessitate further investigation. While the mitochondrial synthase utilizes the proton gradient generated by oxidative phosphorylation to power ATP synthesis, the cell surface synthase has instead been implicated in numerous activities, including the mediation of intracellular pH, cellular response to antiangiogenic agents, and cholesterol homeostasis. Intriguingly, a common thread uniting these various models of cell surface ATP synthase functions is the apparently caveolar distribution of the enzyme. Recent studies concerning the cell surface ATP synthase manifest applications in the regulation of serum cholesterol levels, cellular proliferation and antitumor strategies. This review addresses the expression, interactions, functions, and consequences of inhibition of cell surface ATP synthase, an enzyme now displaying a shift in paradigm, as well as of location.
Injection of bubbling liquid jets from multiple injectors into a supersonic stream

Multiple (12 injectors) bubbling liquid jets (helium microbubbles in water) were injected transverse to a M = 2.4 airflow. Penetration and spray plume spreading angle were measured directly using nanoshadowgraphs and front-lighted pictures, respectively. The experiments were performed at two conditions, i.e., the constant supply pressure condition and the constant liquid mass flow rate condition. For the case of a parallel arrangement of the injector orifices to the airflow, the penetration of the jet array increased steadily from front to back. The last jet (12th jet) has over 5 times the penetration of the first jet for the water only case. The usual similarity law for the penetration, h * q°-59 was approximately valid also for the multiple water-only jets. For the bubbling jet case, the penetration of the first jet doesn't change with increasing gas concentration y, but the rear jets have less penetration height than that of liquid-only jets at the constant injection pressure condition. For the constant injection pressure condition, the resulting penetration of the jet plume decreased with increasing y. On the other hand, for the constant liquid mass flow rate condition, the penetration of the multiple bubbling jets increased a little with increasing y. Straight coherent jets just coming out of orifice were observed for the y = 0 case. Conical jet plumes were obtained for the bubbling jet case. Therefore, the width of the jet plume increased by using the bubbling jet. The effects of the angle between the orifice array and the freestream direction and the surfactant concentration on the penetration and mixing of multiple bubbling jets were also clarified.
Water Resources Systems Planning: Some Case Studies for India

The book Water Resources Systems Planning: Some Case Studies for India is a collection of papers presenting the applications of water resources planning models in the Indian subcontinent. The contention of the book is that the water resources development of India should be predicated on the systems methodology, primarily because of the vagaries of the continent's arid monsoon climate, the key role that water has in agricultural planning, and the necessity of coordinating national, regional, and basinwide development programs. The dissemination of the results of the systems planning studies is the overriding objective of the book.
A numerical study of the effects of atmospheric and wake turbulence on wind turbine dynamics

Although the atmospheric sciences community has been studying the effects of atmospheric stability and surface roughness on the planetary boundary layer for some time, their effects on wind turbine dynamics have not been well studied. In this study, we performed numerical experiments to explore some of the effects of atmospheric stability and surface roughness on wind turbine dynamics. We used large-eddy simulation to create atmospheric winds and compute the wind turbine flows, and we modeled the wind turbines as revolving and flexible actuator lines coupled to a wind turbine structural and system dynamic model. We examined the structural moments about the wind turbine blade, low-speed shaft, and nacelle; power production; and wake evolution when large 5-MW turbines are subjected to winds generated from low- and high-surface roughness levels representative of offshore and onshore conditions, respectively, and also neutral and unstable atmospheric conditions. In addition, we placed a second turbine 7 rotor...
Differential Regulation of a Fibroblast Growth Factor-Binding Protein during Skin Carcinogenesis and Wound Healing

The initiation of premalignant lesions is associated with subtle cellular and gene expression changes. Here we describe a severe combined immunodeficient mouse xenograft model with human adult skin and compare chemical carcinogenesis and wound healing. We focus on a secreted binding protein for fibroblast growth factors (FGF-BP) that enhances the activity of locally stored FGFs and is expressed at high levels in human epithelial cancers. Carcinogen treatment of murine skin induced papilloma within 6 weeks, whereas the human skin grafts displayed no obvious macroscopic alterations. Microscopic studies of the human skin, however, showed p53-positive keratinocytes in the epidermis, increased angiogenesis in the dermis of the treated skin, enhanced proliferation of keratinocytes in the basal layer, and an increase of FGF-BP protein and mRNA expression. In contrast, after surgical wounding of human skin grafts or of mouse skin, FGF-BP expression was upregulated within a few hours and returned to control levels after 2 days with wound closure. Enhanced motility of cultured keratinocytes and dermal fibroblasts by FGF-BP supports a role in wound healing. We conclude that adult human skin xenografts can be used to identify early molecular events during malignant transformation as well as transient changes during wound healing.
Spectroscopy of the methane ν 3 band with an accurate midinfrared coherent dual-comb spectrometer

We demonstrate a high-accuracy dual-comb spectrometer centered at 3.4 $\ensuremath{\mu}$m. The amplitude and phase spectra of the $P$, $Q$, and partial $R$ branches of the methane ${\ensuremath{\nu}}_{3}$ band are measured at 25 to 100 MHz point spacing with resolution under 10 kHz and a signal-to-noise ratio of up to 3500. A fit of the absorbance and phase spectra yields the center frequency of 132 rovibrational lines. The systematic uncertainty is estimated to be 300 kHz, which is ${10}^{\ensuremath{-}3}$ of the Doppler width and a 10-fold improvement over Fourier transform spectroscopy. These data quantify the accuracy and resolution achievable with direct comb spectroscopy in the midinfrared.
NO-FREE-LUNCH EQUIVALENCES FOR EXPONENTIAL LÉVY MODELS UNDER CONVEX CONSTRAINTS ON INVESTMENT

We provide equivalence of numerous no-free-lunch type conditions for financial markets where the asset prices are modeled as exponential Levy processes, under possible convex constraints in the use of investment strategies. The general message is the following: if any kind of free lunch exists in these models it has to be of the most egregious type, generating an increasing wealth. Furthermore, we connect the previous to the existence of the numeraire portfolio, both for its particular expositional clarity in exponential Levy models and as a first step in obtaining analogues of the no-free-lunch equivalences in general semimartingale models, a task that is taken on in Karatzas and Kardaras (2007).
Reconciliation of Trends in Global and Regional Economic Losses from Weather Events: 1980–2008

AbstractIn recent years, claims have been made in venues including the authoritative reports of the Intergovernmental Panel on Climate Change (IPCC) and in testimony before the U.S. Congress that e...
A Psychometric Evaluation of the DSM-IV Pathological Gambling Diagnostic Criteria

Specific diagnostic criteria for pathological gambling (PG) have been available for 25 years, since the publication of DSM-III. Little research has examined the psychometric performance of the diagnostic criteria. The goal of the present report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project was to examine the sensitivity, specificity and predictive values of the DSM-IV PG criteria for psychiatric outpatients who screened positive for a gambling problem. A total of 1709 psychiatric outpatients were evaluated with a semistructured diagnostic interview for PG. Of all patients 88 screened positive for PG, 40 of whom met DSM-IV diagnostic criteria for a lifetime history of PG. All ten DSM-IV criteria were significantly more frequent in the PG group. The sensitivity of the criteria ranged from 25.0% to 90.0% (mean = 67.8%), whereas specificity ranged from 62.5% to 100% (mean = 81.9%). Positive predictive values ranged from 64.1% to 100% (mean = 78.9%), and negative predictive values ranged from 61.5% to 90.7% (mean = 77.1%). Guidelines are recommended for determining whether a diagnostic criterion should be retained as part of the set of diagnostic criteria, and our results suggested that two of the DSM-IV PG criteria are candidates for elimination (criterion 8—commitment of illegal acts; criterion 10—reliance on others for financial assistance to relieve a desperate financial problem).
433 STUDIES IN NECROTIZING ENTEROCOLITIS (NEC): EFFECTS OF FORMULAS ON G.I. MICROBIAL FLORA

NEC appears to be of multifactorial origin. Bacteria may be important as shown by one study in which 67% of patients with NEC harbored Klebsiella in the GI tract. That organism produces enterotoxins and endotoxins, and invades the systemic circulation readily when the gut mucosa is compromised. Human milk may protect against NEC by altering the fecal flora as it does against neonatal diarrhea (Gyorgi). Previously we found no difference in quantities of stool endotoxin in full-term infants fed fresh breast milk or a proprietary formula; with increased feedings there were more GI microorganisms and endotoxin production. We have now studied the GI bacterial flora of neonates in an ICU who were fed Enfamil and a humanized formula (SMA). Infants between 1,500 and 2,250 gms at birth were assigned weight groups differing by 250 gms, and chosen randomly to be fed 1 of the 2 formulas. Infants in distress or receiving antibiotics were excluded. Klebsiella appeared more often in the stools of infants fed Enfamil (p< 0.05); Bacteroides fragilis was detected more often with SMA (p<0.05). Both formulas supported growth of E. coli and Clostridium equally. The formulas used in this study affected the microbial flora of the nursery population. Outbreaks of NEC and the course of the disease may be influenced by the type of formula fed as well as the feeding regimen.
Induction of nuclear transport with a synthetic peptide homologous to the SV40 T antigen transport signal

A system was developed for the analysis of protein transport to the nucleus. Carrier proteins cross-linked to synthetic peptides were microinjected into the cytoplasm of mammalian cells, and protein transport was evaluated by immunofluorescence staining of fixed cells. A 13-mer synthetic peptide containing seven amino acids homologous to SV40 T antigen was capable of inducing nuclear transport, but no transport was observed when proteins were coupled with a synthetic peptide homologous to a nuclear-transport-defective T antigen. The largest protein-peptide conjugate efficiently transported was ferritin (Mr 465,000). The rate of transport was influenced by the number of peptides per molecule of carrier protein and, to some degree, by the size of the carrier protein. Transport of some conjugates was almost complete in 15 min at room temperature.
210Pb and 137Cs chronology of sediments from small, shallow Arctic lakes

Abstract Arctic environmental conditions present special difficulties with the use of nuclides 210Pb and 137Cs for measuring lake sediment chronology. Fluxes of these nuclides are lower in the Arctic than in mid-latitudes, shortening the history that can be resolved. Ice prevents atmospheric input of nuclides to sediment during much of the year and can cause redistribution of sediment in shallow lakes. Results from analyses of seven sediment cores from two lakes on the Belcher Islands in southeastern Hudson Bay show that sediment redistribution by ice is a major process in one of the lakes. In order to measure an undisturbed sedimentation rate, it is necessary that a total input or flux of 137Cs and 210Pb be measured or estimated. Total unsupported 210Pb in the area, 14.8 dpm/cm2, is the average of measurements in three cores from two lakes that have consistent total 137Cs inventories closest to the estimated 137Cs flux. Cores from undisturbed sites have slower sedimentation rates, and 137Cs appears in layers dated before the early 1950s when it would have first appeared in sediment. 137Cs cannot be used for chronological evaluation of these cores. Mixing of surface sediment layers and lower dating resolution than in other cores are responsible for the apparent downward movement of this nuclide. 210Pb measurements of undisturbed sedimentation rates in the lakes range from 0.0044 to 0.0180 g/cm2/a. The sedimentation rate in a lake used for raw sewage oxidation doubled after the beginning of sewage input. Rates at sites where sediment is redistributed range from 0.0259 to 0.0309 g/cm2/a with similarly higher total 137Cs and unsupported 210Pb values. Dates of sediment layers measured using the constant rate of supply model are verified by 210Pb profile discontinuities corresponding to major storms in 1958 and in 1940.
Mercury temporal trends in top predator fish of the Laurentian Great Lakes

Mercury (Hg) contamination is widespread in the Laurentian Great Lakes region and is a serious environmental concern. In anaerobic environments such as lake sediments, mercury is transformed into methylmercury (MeHg) and can biomagnify up the food chain to toxic concentrations. The Great Lakes Fish Monitoring Program (GLFMP), administered by the US EPA Great Lakes National Program Office (GLNPO), aims to monitor temporal trends of mercury in the five Great Lakes using top predator fish as biomonitors. Total Hg (THg) concentrations were measured in Great Lake fish collected between 1999 and 2009. Single factor ANOVA determined that average fish THg concentrations over this time period in the five lakes were significantly different from one another in the order of Superior > Huron > Michigan > Ontario > Erie. By fitting the data to three different models (linear, quadratic, and two-segment piecewise), it was determined that Hg concentrations in top predator fish (lake trout, or walleye in Lake Erie) are currently increasing in Lake Erie and the Apostle Island sampling site in Lake Superior. Significant decreasing trends are evident in Lakes Michigan, Ontario, and the Rockport sampling site in Lake Huron, although all of the lakes exhibit elevated concentrations in fish compared to historic concentrations. As new Hg emission controls are implemented in the US, continued monitoring of Hg in Great Lakes fish will be needed to determine if they influence the current concentrations and trends.
Role of therapeutic radiology in cancer of bone.

Management of patients with Ewing's sarcoma has been discussed with reference to the need to achieve an excellent local result from radiation therapy now that patients are experiencing long-term survival. The technique of biopsy is important: small scar; located within treatment portal; positioning such that there is a good connective tissue bed (e.g. not immediately overlying bone); tissue obtained from soft tissue component and no cortical bone removed. Radiation therapy technique is based upon: special shaping of the irradiated volume to correspond to estimate distribution of tumor; distribution of dose in accordance with tumor cell number (progressive field reduction); precision setup of patient each day; and high total dose (6000-6600 rads in 6-6.6 weeks). This treatment is to be given in combination with multidrug multicycle chemotherapy. For osteosarcoma, special attention was given to lesions of mandible, where preoperative irradiation and hemimandibulectomy appears to be much more effective than surgery alone.
Strength loss in MA-MOX green pellets from radiation damage to binders

Abstract The fracture strength of green Minor Actinides (MA)-MOX pellets containing 75 wt.% DUO2, 20 wt.% PuO2, 3 wt.% AmO2 and 2 wt.% NpO2 was studied as a function of storage time, after mixing with the binder and before sintering, to test the effect of radiation damage on binders. Fracture strength degraded continuously over the 10 days of the study for all three binders studied: PEG binder (Carbowax 8000), microcrystalline wax (Mobilcer X) and styrene–acrylic copolymer (Duramax B1022) but the fracture strength of Duramax B1022 degraded the least. For instance, for several hours after mixing Carbowax 8000 with MA-MOX, the fracture strength of a pellet was reasonably high and pellets were easily handled without breaking but the pellets were too weak to handle after 10 days. Strength measured using diametral compression test showed that strength degradation was more rapid in pellets containing 1.0 wt.% Carbowax PEG 8000 compared to those containing only 0.2 wt.%, suggesting that irradiation not only left the binder less effective but also reduced the pellet strength. In contrast the strength of pellets containing Duramax B1022 degraded very little over the 10 days period. It was suggested that the styrene portion present in the Duramax B1022 copolymer provided the radiation resistance.
Gingival Grafts: A Historical Note

The use of pedicle or free tissue grafts to cover denuded roots is considered a hallmark of modern periodontics. Recently, we came upon several publications which make it necessary to revise the historical origins of these procedures. In the Dental Cosmos of 1904 there appears a synopsis of a meeting of the American Dental Club of Paris which took place on December 6, 1902 at the office of Drs. (A.B.) Crane and (M.P.) Younger.1 At this meeting Dr. Younger reported that he successfully restored gum on a denuded root by "grafting a piece taken from behind the third molar of the same mouth". It was reported that the graft did contract greatly, but Dr. Younger was still able to obtain "... an increase of tissue about equal to one-fourth of the bulk of the graft". On June 8, 1906 at a joint meeting of the Maryland State Dental Association and the District of Columbia Dental Society held in Washington, DC, Dr. A. W. Harlan presented a paper titled, "Restoration of Gum Tissue on the Labial Aspect of Teeth". This presentation
A framework for predictive dynamic temperature management of microprocessor systems

The sustained push for performance, transistor count and instruction level parallelism has reached a point where IC thermal issues are at the forefront of design constraints. Many of the current systems deploy dynamic voltage and frequency scaling (DVFS) to address thermal emergencies. DVFS has certain limitations in terms of response lag, scalability and being reactive. On the other hand, several hardware based control theoretic schemes have been proposed to deliver optimal performance, but such schemes come at high cost and lack flexibility and scalability. In this paper, we present an alternative thermal monitoring and management system that utilizes software and hardware components, based on virtual machine concept. The proposed scheme delivers targeted, localized, and preemptive thermal management at low cost, adapts well to a multitasking environment, while delivering maximum performance under thermal stress.
A novel technique for efficient parallel implementation of a classical logic/fault simulation problem

A technique is presented for formulating the logic/fault simulation of VLSI array logic in terms of standard vector and matrix operation primitives that are well supported on all scientific supercomputers, high-end mainframes, and minisupercomputers that provide vector parallel hardware and software. The overall computing environment is assumed to be a scientific/engineering one, with Fortran as the primary coding medium and the hardware biased toward numerically intensive applications. >
Time-frequency data reduction for event related potentials: combining principal component analysis and matching pursuit

Joint time-frequency representations offer a rich representation of event related potentials (ERPs) that cannot be obtained through individual time or frequency domain analysis. This representation, however, comes at the expense of increased data volume and the difficulty of interpreting the resulting representations. Therefore, methods that can reduce the large amount of time-frequency data to experimentally relevant components are essential. In this paper, we present a method that reduces the large volume of ERP time-frequency data into a few significant time-frequency parameters. The proposed method is based on applying the widely used matching pursuit (MP) approach, with a Gabor dictionary, to principal components extracted from the time-frequency domain. The proposed PCA-Gabor decomposition is compared with other time-frequency data reduction methods such as the time-frequency PCA approach alone and standard matching pursuit methods using a Gabor dictionary for both simulated and biological data. The results show that the proposed PCA-Gabor approach performs better than either the PCA alone or the standard MP data reduction methods, by using the smallest amount of ERP data variance to produce the strongest statistical separation between experimental conditions.
Relation of Antiphospholipid Antibodies to Postmortem Brain Infarcts in Older People

Background—There are few data on the relationship of antiphospholipid antibodies (aPLs) to pathologically proven brain infarcts. We tested the hypothesis that aPLs are associated with a higher odds of brain infarcts among older, community-dwelling individuals who came to autopsy. Methods and Results—Specimens and clinical and pathological data were derived from 607 deceased subjects (mean age at death, 89 years; 66% women) who were participating in 1 of 2 cohort studies of aging (Rush Memory and Aging Project and Religious Orders Study) and had agreed to brain autopsy. Brain infarcts were identified on gross and microscopic examinations, and severity of cerebral vessel disease (atherosclerosis, arteriolosclerosis) was graded. Four clinically used aPLs were measured longitudinally: 3 in serum (anticardiolipin antibodies, β2-glycoprotein I, and anti–phosphatidyl-serine) and 1 in plasma (lupus anticoagulant). A quarter of subjects (142 of 607, 23%) had at least 1 aPL present at baseline (median time interval...
Substance abuse treatment entry, retention and effectiveness: out-of-treatment opiate injection drug users ☆

Abstract This study was designed to assess the effect of client characteristics and community interventions on treatment entry and retention, and to evaluate the relative effectiveness of treatment, compared to other interventions, in reducing drug use and crime among out-of-treatment opiate injectors. Subjects ( N = 2973) from 15 cities were randomly assigned to: standard intervention (SI)-HIV testing and counseling; or enhanced intervention (EI)-SI plus additional educational sessions stressing responsible drug use. EI in some cities included staff assistance with treatment admission (i.e. ‘active’ referral). All locations provided intervention by community outreach workers. Factors positively associated with treatment entry included: prior treatment, intervention by community workers, assignment to the EI, not injecting cocaine, injecting opiates, and fewer program interventions received. Sites where the EI included active referral achieved significantly higher treatment entry rates than sites where the EI did not. Findings supported the efficacy of treatment over other interventions in reducing drug use and arrests, the addition of staff assistance to facilitate clients' entry into treatment, and the involvement of community outreach workers in achieving treatment entry.
Temperature Dependence of the Collisional Removal of O2(A³Σu+, υ=9) with O2 and N2

The temperature dependence of the collisional removal of O 2 molecules in the υ = 9 level of the A 3 Σ u + electronic state has been studied for the colliders O 2 and N 2 , over the temperature range 150 to 300 K. In a cooled flow cell, the output of a pulsed dye laser excites the O 2 to the υ =9 level of the A 3 Σ u + state, and the output of a time-delayed second laser monitors the temporal evolution of this level via a resonance-enhanced ionization. We find the thermally averaged removal cross section for O 2 collisions is constant (∼10 A 2 ) between room temperature and 200 K, then increases rapidly with decreasing temperature, doubling by 150 K. In contrast, the N 2 cross section at 225 K is ∼ 8 % smaller and gradually increases to a value at 150 K that is - 60% larger than the room temperature value. The difference between the temperature dependence of the O 2 and N 2 collision cross section implies that the removal by oxygen becomes more important at the lower temperatures found in the mesosphere, but removal by N 2 still dominates.
Irradiation Effects on Midguts and Testes of the Adult Boll Weevil, Anthonomus grandis, Determined by Histological and Shielding Studies

Histological studies demonstrated that radiation doses considerably below those required for sterilization killed most regenerative cells of boll weevils, Anthonomus grandis Boheman, which resulted in the loss of most or all of the secretory epithelium. Extensive damage to midgut was noted in 1 specimen that received 2000 R and in all those given 4000 R. Shielding experiments showed that when only the head and that part of the thorax anterior to the midgut were irradiated, mortality did not exceed that of the control. Irradiation over the abdomen and the posterior part of the thorax produced the same level of mortality as did whole-body irradiation. These findings indicate that damage to the midgut is the basic cause of the high mortality among weevils given sterilizing closes of radiation. At 10 days after irradiation, no spermatogonia were found in any testes irradiated with 6000 R or more, and none were found in some testes that received only 2000 R.
Routing Hazardous Materials around the District of Columbia Area

The recent hazardous material (hazmat) shipment ban in Washington, D.C., has led to debates, legal challenges, and considerations by other major cities to pursue similar actions. This article presents a methodology for evaluating hazmat shipment routing options on railroad networks under situations such as the shipment ban. A case study involving three alternatives is presented. Population and other vulnerable people within a 0.8 km (or 0.5 mile) radius buffer zone along the rail line are used to evaluate the potential risk associated with ultra-hazardous material (i.e., explosives, flammable gasses, poisonous gasses, and poisonous materials) shipments. Based on this study, it is concluded that moderate increases in ton-km, and subsequently time in transit, will be a result from the rerouting. On the other hand, the overall population at risk will see a reduction. The population-at-risk burden, however, is simply shifted from one location to other locations. This article also identifies areas for potentia...
Reversible enzymatic acetylation of carnitine.

Abstract 1. 1. An apparent inhibition of enzymatic acetylation of PAB by carnitine has been found to be due to an enzyme which is active in the acetylation of carnitine. 2. 2. This enzyme, which is found in both pigeon and sheep liver extracts, seems to catalyze the following reaction: O-acetylcarnitine + CoA ↔ acetyl CoA + carnitine 3. 3. The possible importance of secondary esters in group-transfer reactions is discussed.
Simultaneous postinfectious glomerulonephritis and thrombotic microangiopathy : A renal biopsy study

The simultaneous occurrence of postinfectious glomerulonephritis and thrombotic microangiopathy is described in renal biopsy specimens from three patients. Each presented with diverse manifestations: two patients had hypertension and acute renal failure, and in the third, it was unclear whether an atypical postinfectious glomerulonephritis or an atypical thrombotic microangiopathy was present. All biopsy specimens disclosed a combination of irregular granular complement and immunoglobulin deposits in mesangial regions and capillary walls along with fibrin in a linear pattern in capillary walls by immunofluorescence. Light microscopy showed diffuse hypercellularity in some glomeruli, endothelial cell swelling, luminal thrombi and mesangiolysis in others, and both types of changes in a third group. Ultrastructurally, subepithelial hump-shaped deposits coexisted with widened and lucent subendothelial spaces. Possible pathogenic mechanisms for the synchronous lesions include endothelial injury, perhaps triggered by infection and immunologic tissue damage.
Theoretical prediction of spectroscopic constants of 1-alkoxy radicals

Abstract Spectroscopic constants for the conformers of the 1-alkoxy radicals were computed by ab initio and density functional methods. These parameters include ground and excited state rotational constants, harmonic frequencies, and A – X and B – X excitation energies. Elements of the electronic spin–molecular rotation tensor have also been predicted for the ground electronic state utilizing a simple transformation. The transformation employed the experimentally observed spin-rotation tensor of the ethoxy radical as a reference and the calculated rotational constants of the ethoxy radical and the investigated 1-alkoxy radicals. The predicted spectroscopic parameters are in good agreement with the experimental ones where available, and found to be useful parameters for assigning the rotationally resolved spectral bands to given conformers.
Stokes matrix of a one-dimensional perfectly conducting rough surface

We study theoretically the Stokes matrix of a perfectly conducting, one-dimensional rough surface that is illu-by a polarized light beam of finite width whose plane of incidence is perpendicular to the grooves of the minated surface. An exact expression for the scattered field derived from Green’s second integral theorem is used to the angular distribution of the Stokes matrix that has eight nonzero elements, four of which are compute unique. Results are presented for the numerical calculation of each matrix element averaged over an ensemble of surface profiles that are realizations of a stationary, Gaussian stochastic process. All four unique matrix elements are significant, with the diagonal elements displaying enhanced backscattering and the off-diagonal elements having complicated angular dependences including structures in the retroreflection direction. With the use of a single source function evaluated through the iteration of the surface integral equation obtained from the extinction theorem for the p-polarized field, we derive an approximate expression for the Stokes matrix that indicates that multiple scattering plays an important role in the polarized scattering from a perfectly conducting rough surface that displays enhanced backscattering. The numerical calculation of each of the con-to the Stokes matrix, taking into account single-, double-, and triple-scattering processes, enables us tributions to assign the main features of the Stokes matrix to particular multiple-scattering processes. Experimental measurements of the matrix elements are presented for a one-dimensional Gaussian surface fabricated in gold-photoresist. The results are found to be reasonably consistent with the theory, although we suggest that coated differences in one matrix element may be due to the finite conductivity of the experimental surface.