cssi/SciSciGPT-SciSciNet huggingface dataset:
Limited co-operativity in protein-nucleic acid interactions: A thermodynamic model for the interactions of Escherichia coli single strand binding protein with single-stranded nucleic acids in the “beaded”, (SSB)65 mode

We present a statistical thermodynamic model ("tetramer/octamer" model) that describes the equilibrium binding of the Escherichia coli single strand binding (SSB) protein to single-stranded nucleic acids in its "beaded" binding mode, which seems to be equivalent to the high site size, (SSB)65 binding mode. The method of sequence-generating functions is used to derive the model, which accounts for the observation that clustering of bound SSB tetramers is limited to the formation of octamers, which have been observed as "beads" in the electron microscope. The model also accounts for the overlap of potential protein binding sites on the nucleic acid. The "tetramer/octamer" model is fully described by only three parameters: the site size, n; the intrinsic equilibrium constant, K; and the co-operativity parameter, omega, and we obtain exact, closed form expressions for the binding isotherm as well as the distribution of DNA-bound SSB tetramers and octamers. The closed form expressions allow one to calculate easily average binding properties and analyze experimental binding isotherms to obtain estimates of K and omega. In order to test the tetramer/octamer model, we have determined the equilibrium binding isotherm for the E. coli SSB protein-poly(U) interaction in 0.2 M-NaCl over a wide range of binding densities. These are conditions in which the low co-operativity (SSB)65 binding mode solely exists. The tetramer/octamer model provides a much better description of the experimental isotherm over the entire binding density range than a model that assumes the formation of clusters of unlimited size. A co-operativity parameter of omega = 420 +/- 80 provides a good fit to data for SSB binding to poly(dA) and poly(U), corresponding to an interaction free energy of -3.6 kcal/mol of SSB octamer formed. On the basis of this moderate value of omega, the tetramer/octamer model predicts that at low to intermediate binding densities, a significant fraction of bound SSB exists in the form of tetramers co-existing with octamers. In the case of E. coli SSB protein binding in the "beaded", (SSB)65 mode this model provides a significant improvement over previous treatments which assume unlimited nearest-neighbor interactions, since the binding parameters, K and omega, represent physically meaningful interaction constants rather than fitting parameters.
DNA polymerase I activity in Escherichia coli is influenced by spot 42 RNA.

Abstract We have shown that the level of DNA polymerase I (Pol I) activity in Escherichia coli is influenced by the level of a 109-nucleotide RNA, spot 42 RNA. Deletion of the gene for spot 42 RNA results in a 20 to 25% decrease in Pol I activity, as assayed by nucleotide incorporation in cell extracts and a decrease in the ability of cells to grow in the presence of the DNA-alkylating agent methyl methanesulfonate. Also, a physiological reduction of the level of spot 42 RNA, by growth in media containing poor carbon sources, results in a corresponding decrease in Pol I activity. Conversely, overproduction of spot 42 RNA results in a 10 to 15% increase in Pol I activity in vitro. Thus, changes in the amount of spot 42 RNA result in relatively small but significant changes in Pol I activity.
Avoidable tragedies: Disparities in healthcare access among medically underserved women diagnosed with cervical cancer☆

Abstract Background The purpose was to identify barriers including logistical and health belief correlates of late stage presentation of cervical cancer (CxCa) among medically underserved women presenting to a safety net health care system. Methods Women presenting with newly diagnosed CxCa were asked to complete a detailed health belief survey that included questions about barriers to care and their knowledge of CxCa. All information was collected prior to initiating cancer treatment. Comparisons were made among women diagnosed at early stages of disease amendable to surgical treatment (≤IB1) and those diagnosed at a stage requiring local–regional or systemic/palliative treatment (≥IB2). Results Among the 138 women, 21.7% were diagnosed with ≤lB1 disease, while 78.3% were diagnosed with ≥IB2 disease. Late-stage diagnosis was associated with a greater number of emergency room (ER) visits (p Conclusion Access to transportation and lack of a regular primary care provider or a medical home are associated with late-stage of CxCa at diagnosis. Many medically underserved women continue to use the ER as their primary source of health care, and as a result their CxCa is diagnosed in advanced stages, with higher medical costs and lower chances of cure. The lack of Medicaid expansion in Texas may result in a worsening of this situation.
Translating CFC-based piston ages into probability density functions of ground-water age in karst

Temporal age distributions are equivalent to probability density functions (PDFs) of transit time. The type and shape of a PDF provides important information related to ground-water mixing at the well or spring and the complex nature of flow networks in karst aquifers. Chlorofluorocarbon (CFC) concentrations measured for samples from 12 locations in the karstic Madison aquifer were used to evaluate the suitability of various PDF types for this aquifer. Parameters of PDFs could not be estimated within acceptable confidence intervals for any of the individual sites. Therefore, metrics derived from CFC-based apparent ages were used to evaluate results of PDF modeling in a more general approach. The ranges of these metrics were established as criteria against which families of PDFs could be evaluated for their applicability to different parts of the aquifer. Seven PDF types, including five unimodal and two bimodal models, were evaluated. Model results indicate that unimodal models may be applicable to areas close to conduits that have younger piston (i.e., apparent) ages and that bimodal models probably are applicable to areas farther from conduits that have older piston ages. The two components of a bimodal PDF are interpreted as representing conduit and diffuse flow, and transit times of as much as two decades may separate these PDF components. Areas near conduits may be dominated by conduit flow, whereas areas farther from conduits having bimodal distributions probably have good hydraulic connection to both diffuse and conduit flow.
Risks of mortality and morbidity from worldwide terrorism: 1968-2004.

Worldwide data on terrorist incidents between 1968 and 2004 gathered by the RAND Corporation and the Oklahoma City National Memorial Institute for the Prevention of Terrorism (MIPT) were assessed for patterns and trends in morbidity/mortality. Adjusted data analyzed involve a total of 19,828 events, 7,401 "adverse" events (each causing >/= 1 victim), and 86,568 "casualties" (injuries), of which 25,408 were fatal. Most terror-related adverse events, casualties, and deaths involved bombs and guns. Weapon-specific patterns and terror-related risk levels in Israel (IS) have differed markedly from those of all other regions combined (OR). IS had a fatal fraction of casualties about half that of OR, but has experienced relatively constant lifetime terror-related casualty risks on the order of 0.5%-a level 2 to 3 orders of magnitude more than those experienced in OR that increased approximately 100-fold over the same period. Individual event fatality has increased steadily, the median increasing from 14% to 50%. Lorenz curves obtained indicate substantial dispersion among victim/event rates: about half of all victims were caused by the top 2.5% (or 10%) of harm-ranked events in OR (or IS). Extreme values of victim/event rates were approximated fairly well by generalized Pareto models (typically used to fit to data on forest fires, sea levels, earthquakes, etc.). These results were in turn used to forecast maximum OR- and IS-specific victims/event rates through 2080, illustrating empirically-based methods that could be applied to improve strategies to assess, prevent, and manage terror-related risks and consequences.
The oral gold compound auranofin triggers arachidonate release and cyclooxygenase metabolism in the alveolar macrophage.

We examined the effect of in vitro incubation with the oral gold compound auranofin (AF) on arachidonic acid (AA) release and metabolism by rat alveolar macrophages (AMs). AF stimulated dose- and time-dependent release of /sup 14/C-AA from prelabeled AMs, which reached 4.7 +/- 0.3% (mean +/- SEM) of incorporated radioactivity at 10 micrograms/ml for 90 min, as compared to 0.5 +/- 0.1% release following control incubation for 90 min (p less than 0.001). Similar dose- and time-dependent synthesis of thromboxane (Tx) A2 (measured as TxB2) and prostaglandin (PG) E2 was demonstrated by radioimmunoassay of medium from unlabeled cultures, reaching 18-fold and 9-fold, respectively, of the control values at 10 micrograms/ml AF for 90 min (p less than 0.001 for both). AF-induced TxB2 and PGE2 synthesis was inhibited by indomethacin as well as by pretreatment with methylprednisolone. No increase in the synthesis of immunoreactive leukotrienes (LT) B4 or C4 was noted at any dose or time of AF. High performance liquid chromatographic separation of /sup 14/C-eicosanoids synthesized by prelabeled AMs confirmed that AF induced the release of free AA and its metabolism to cyclooxygenase, but not 5-lipoxygenase, metabolites. The ability of AF to trigger macrophage AA metabolism may be relevant tomore » the exacerbation of certain inflammatory processes which sometimes accompany gold therapy.« less
Abyssal community analysis from replicate ☐ cores in the central North Pacific

Abstract A 0·25 m 2 United States Naval Electronics Laboratory ☐ corer was used to take replicate samples from an oligotrophic bottom under the North Pacific Central Water Mass (∼ 28°N, 155°W). The bottom is a red clay with manganese nodules at a depth of 5500–5800 m. Macrofaunal density ranges from 84 to 160 individuals per m 2 and is therefore much the same as in Northwest Atlantic Gyre waters. Of the macrofaunal taxa, polychaetes dominate (55%), followed by tanaids (18%), bivalves (7%), and isopods (6%). Meiofaunal taxa were only partially retained by the 297 μm screen used in washing. Even then, they are 1·5–3·9 times as abundant as the macrofaunal taxa, with nematodes being numerically dominant by far. Foraminifera seem to comprise an important portion of the community, but could not be assessed accurately because of the inability to discriminate living and dead tests. Remains of what are probably xenophyophoridans are also very important, but offer the same problem. Faunal diversity is extremely high, with deposit feeders comprising the overwhelming majority. Most species are rare, being encountered only once. The distributions of only three species show any significant deviation from randomness. The polychaete fauna from ☐ cores collected from 90 miles to the north was not significantly different from that of the principal study locality. Concordance appeared at several taxonomic levels, from species through macrofaunal/meiofaunal relationships. As a result, the variation in total animal abundance shows aggregation among cores. We discuss Sokolova's concept of a deep-sea oligotrophic zone dominated by suspension feeders, and reconcile it with our present findings. The high diversity of the fauna combined with the low food level contradict theories that relate diversity directly with productivity.
The effects of interannual climate variability on the moraine record

Valley glacier moraines are commonly used to infer past mean annual precipitation and mean melt-season temperature. However, recent research has demonstrated that, even in steady climates, multi-decadal, kilometer-scale fluctuations in glacier length occur in response to stochastic, year-to-year variability in mass balance. When interpreting moraine sequences it is important to include the effect of interannual weather variability on glacier length; moraines record advances that are forced either by interannual variability or by a combination of climate change and interannual variability. We address this issue for the Last Glacial Maximum (LGM) glaciers of the Colorado Front Range, United States. Using a linear glacier model that allows thorough exploration of parameter uncertainties, supplemented by a shallow-ice flowline model, our analyses suggest that (1) glacial standstills longer than 50 years were unlikely; (2) mean glacier lengths are ∼10%–15% up-valley from maximum glacier lengths; and (3) individual LGM terminal moraines were formed by a combination of a climate change and interannual variability–forced advances.
REVIEW OF NON-INTRUSIVE ADVANCED SENSOR DEVICES FOR ADVANCED TRAFFIC MANAGEMENT SYSTEMS AND RECENT ADVANCES IN VIDEO DETECTION

AbstractAs performance requirements for advanced traffic management systems (ATMSs) increase, the need for new sensors leading to the next-generation traffic management systems is manifested. In sp...
Linear equations for the development of non‐normalized T‐score tables based on the contemporary normative study of the MMPI

In the contemporary normative study of the Minnesota Multiphasic Personality Inventory (MMPI), the authors recommended the use of normalized T scores so that a given T score would have an equivalent percentile rank across all clinical scales. However, the use of normalized T scores has been debated in the literature. This article presents linear transformation equations that can be used to produce non-normalized T scores similar to those traditionally used on MMPI profiles but based on data from the contemporary normative study of the MMPI. Use of these equations will facilitate comparisons between normalized and non-normalized scores.
Developmental changes in energy metabolism ofSchistosoma mansoni and physiological role of oxygen in maintaining parasite function.

The time course of the conversion from a cyanide-sensitive to a cyanide-insensitive energy metabolism in immatureSchistosoma mansoni was followed by correlating transitions in CO2 and lactate formation with physiological properties of the parasite. Volume conducted electrical potentials and measurement of CO2 evolution indicate that 3-hr posttransformational schistosomula are highly sensitive to 1 mM cyanide. By 24 hr after transformation, evolution of CO2 under control conditions is reduced by 77% from 3-hr levels, while lactate excretion rises by 84%. At the 24-hr stage, neither cyanide nor rotenone affects the frequency or magnitude of endogenous electrical transients, but cyanide does eliminate 83 % of the already reduced levels of CO2 evolved in 24-hr schistosomula. The adult parasite evolves a low level of CO2 which is reduced by 88% in the presence of 1 mM cyanide. No significant Pasteur effect is detected, however, and endogenous electrical activity as well as mechanical responses of the adult musculature are unaffected by cyanide exposure. Furthermore, adult schistosomes were not adversely affected in terms of the physiological parameters measured by 24-hr incubations in oxygen-free medium. Adults were only marginally affected by 24-hr exposure to several respiratory inhibitors, but responded rapidly to some uncouplers of oxidative phosphorylation, including 2,4-DNP, carbonyl cyanide 3-chlorphenylhydrazone, and closantel. Our results indicate that schistosomula continue to rely on cyanide-sensitive respiratory components for at least 3 hr after transformation; by 24 hr, however, the parasites are metabolically similar to the adult stage, i.e, they depend on lactate fermentation for most of their energy requirements.
Cortico-Cerebellar Coherence and Causal Connectivity During Slow-Wave Activity

Cerebral cortical slow-wave activity (SWA) is prominent during sleep and also during ketamine-induced anesthesia. SWA in electroencephalogram (EEG) recordings is closely linked to prominent fluctuations between up- and down-states in the membrane potential of pyramidal neurons. However, little is known about how the cerebellum is linked into SWA and whether slow cortical oscillations influence sensory cerebellar responses. To examine these issues, we simultaneously recorded EEG activity from the cerebral cortex (SI, MI, and supplementary motor area (SMA)), local field potentials at the input stage of cerebellar processing in the cerebellar granule cell layer (GCL) and inferior olive (IO), and single unit activity at the output stage of the cerebellum in the deep cerebellar nuclei (DCN). We found that in ketamine-anesthetized rats, SWA was synchronized between all recorded cortical areas and was phase locked with local field potentials of the GCL, IO and single unit activity in the DCN. We also found that cortical up-states are linked to activation of GCL neurons but to inhibition of cerebellar output from the DCN, with the latter an effect likely mediated by Purkinje cells. A partial coherence analysis showed further that a large portion of SWA shared between GCL and DCN was transmitted from the cortex, since the coherence shared between GCL and DCN was diminished when the effect of cortical activity was subtracted. To determine the causal flow of information between structures, a directed transfer function was calculated between the simultaneous activities of SI, MI, SMA, GCL and DCN. This analysis demonstrated that the primary direction of information flow was from cortex to the cerebellum and that SI had a stronger influence than other cortical areas on DCN activity. The strong functional connectivity with SI in particular is in agreement with previous findings of a strong cortical component in cerebellar sensory responses.
Intraoperative localization of ectopic gastric mucosa in the nonduplicated intestinal lumen with technetium 99m pertechnetate scanning.

Abstract The occurrence of ectopic gastric mucosa in Meckel's diverticula and duplications of the intestinal tract is a source of serious morbidity from bleeding and perforation in children. Intraoperative localization of the ectopic mucosa is aided by its occurence in the duplicated intestinal segment or Meckel's diverticulum. However, its identification in the nonduplicated intestine poses problems for the surgeon faced with removal of the affected segment. The authors present a case of ectopic gastric mucosa in a nonduplicated jejunal segment and discuss the use of technetium 99m pertechnetate scanning in its localization. J Pediatr Surg 36:1720-1721. Copyright © 2001 by W.B. Saunders Company.
Examination of mouse and rat tissues for evidence of dual forms of the fatty acid cyclooxygenase

The possibility that the enzymatic generation of prostaglandin E2 (PGE2) and PGF2 alpha results from the catalytic activity of two distinct forms of the fatty acid cyclooxygenase was studied in microsomes prepared from kidney, lung, and brain of the mouse and rat. Three criteria established previously to detect the dual cyclooxygenase forms in the rabbit brain were used in the present study: (1) different time course profiles of microsomal PGE2 and PGF2 alpha biosynthesis from exogenous arachidonic acid; (2) elimination of the synthesis of one PG in vitro by non-steroidal anti-inflammatory drug concentrations that did not affect the synthesis of the other PG and; (3) selective autocatalytic inactivation of one cyclooxygenase by preincubation with arachidonic acid. Incubations with PGH2 endoperoxide as substrate tested whether the altered PG biosynthesis resulted from an effect on the endoperoxide utilizing enzymes and not on the cyclooxygenase. Of the six tissues examined, only the mouse brain microsomes satisfied all the criteria. The microsomes prepared from the mouse kidney produced mixed results. We conclude that the mouse brain but not the rat brain gives evidence for two distinct forms of the fatty acid cyclooxygenase. Additional distinguishing features of the different cyclooxygenases are required to determine if the cyclooxygenase forms are found in mouse kidney.
H. J. Muller and R. A. Fisher on the evolutionary significance of sex.

Les interpretations genetiques de H.J. Muller et R.A. Fisher sur l'evolution sexuelle sont comparees a celle de Weismann (A.). L'A. demontre que les explications de Fisher et Muller sont fondees sur l'existence de mutations genetiques des populations, alors que Weismann fonde sa theorie sur des mecanismes genetiques creant de nouveaux phenotypes
Optimal Phase Ordering of Traffic Signals to Reduce Stopped Delay

Congestion in road network results in prolonged travel time to the general public, adds extra cost to economic activities, and raises the pressure on road safety and environment. Traffic signals are an elementary component of all urban road networks and play a critical role in controlling the flow of vehicles. However, current road transportation systems and traffic signal implementations are very inefficient. The objective of this research is to evaluate optimal phase ordering within a signal cycle to minimize the average waiting delay of vehicles and thus in turn minimize fuel consumption and greenhouse gas (GHG) emissions. Through extensive simulation analysis, we show that by choosing optimal phase ordering, the stopped delay can be reduced by 40% per car at each signal resulting in a saving of up to 100 gallons of fuel per traffic signal each day.
Selectivity enhancement by flow injection analysis

Abstract Flow injection analysis offers numerous possibilities for significantly increasing the selectivity of existing methods by utilizing knowledge of the chemistry of those methods. It also enables new selective methods to be created by utilizing kinetic methods and fast separation techniques such as gas diffusion, dialysis, extraction and ion-exchange columns. Selectivity enhancements and increased sensitivity can be achieved by incorporating the kinetic techniques of kinetic discrimination and/or kinetic enhancement into the timing of the system or the reagent concentrations and conditions for a given method. Methods have been developed for quantifying ozone, chlorine dioxide, chlorate ion, and chlorite and chlorate ions sequentially. A dual-phase gas diffusion system for hydride generation provides significant decreases in the interferences observed for transition metals.
Career-Related Antecedents and Outcomes of Job Rotation

Drawing on related literature and an inductive pilot study, we propose a conceptual framework for the relationship between job rotation and selected career-related variables. A test on 255 employee...
Lewis H. Morgan and His Contemporaries

How Lewis H. Morgan came to do what he did has been much commented on, not always accurately. Manuscripts preserved in the papers Morgan bequeathed to the University of Rochester correct these errors, provide insights into how Morgan went about doing research, and suggest the relevance of his work to issues still being discussed.
Recycling is not garbage: market agents and municipal recycling in New York City

Regulatory mechanisms for post-consumer recycling have come under criticism over the past decade. This essay considers the perceived flaws of New York City's recycling programmes and offers a discussion of the role one set of market agents, scrap material dealers, has played (both since the 19th century and presently) in closing industrial loops may illuminate the strengths and limitations of market approaches. This essay addresses the history by considering recent criticisms of municipal recycling practices in New York City, the effectiveness of scrap firms in improving those practices, and a discussion of what scrap firms do and do not do to close industrial loops.
Indication of an Anal Pore in Gnathostomulida

Two species of Haplognathia (Gnathostomulida, Filospermoidea) were examined by electron microscopy and found to possess a tissue connection between the posterior end of the intestine and the dorsal epidermis. This anal tissue connection is characterized by a thinned out epidermis, interdigitation of epidermal and intestinal cells, and the absence of the basement membrane. An open anal pore was not observed. It is possible that the anal tissue connection of Haplognathia serves as a functional anal pore. The implications of this discovery with respect to the various theories of early Metazoan evolution are discussed.
The critical period for ethanol effects on cholinergic neuronal expression in neuroblast-enriched cultures derived from 3-day-old chick embryo: NGF ameliorates the cholinotoxic effects of ethanol

Studies from our laboratory have established that ethanol exerts morphological and biochemical neurotoxic effects during early neuroembryogenesis in the chick brain both in ovo and in culture. In the present study, we further localized the critical period for ethanol effects on cholinergic neuronal expression using neuroblast-enriched cultures derived from 3-day-old chick embryos. Moreover, we report that NGF attenuated the cholinotoxic effects of ethanol. We used the following experimental paradigms: cultures treated with ethanol alone either C0-C3 or C4-C10; NGF alone CO-C4 or C4-C10; ethanol and NGF given concomitantly; ethanol given first then replaced with NGF in the medium; or NGF given first then replaced with ethanol in the medium. The results revealed: 1. (1) the cholinotoxic effect of ethanol occurs between culture days CO and C4 with day 3 appearing to be most critical. 2. (2) similarly, the critical period for the cholinotoxic effects of NGF is during early neuroblast differentiation, culture days CO-C4. 3. (3) NGF can prevent the cholinotoxic effects of ethanol only if both ethanol and NGF are given concomitantly or if ethanol is given first, then culture is replaced with NGF-containing medium.
The politics and mythology of organized crime: A Philadelphia case-study

Abstract Although much criticized, the “Cosa Nostra” theory of organized crime continues to exert considerable influence over lawmakers and law enforcement officials. This theory has been extensively studied on a national level, but few local case studies trace the transition from the multiethnic organized crime of the 1930s and 1940s to the (supposed) Italian hegemony of the years since 1960. Philadelphia provides an excellent opportunity for such a study, as the base of a strong Jewish-dominated structure before 1960 and a “Mafia town” thereafter. A major concern of this article is the manner in which the history of crime in the city was retroactively rewritten during the 1970s, in order to provide a basis for contemporary theories and bureaucratic needs.
Use of frozen section in genitourinary pathology

Frozen section diagnosis provides critical information for immediate surgical management decision making. Over the last several years, there have been some significant advances in treatment of genitourinary cancer, particularly with regard to surgical techniques. These changes in turn impact the type and frequency of intraoperative frozen section requests. In this review, we describe the main indications and diagnostic challenges of frozen section diagnosis during surgeries of each genitourinary organ system including prostate, kidney, bladder, testis, and penis. The pitfalls and approaches to different diagnostic situations are discussed. It is also stressed that pathologists must not only be familiar with the histological diagnosis, but also understand the limitations of frozen section diagnosis and communicate with urologists during the intraoperative treatment decision making process.
The world metropolis and the history of American agriculture.

Since agricultural history first acquired independent status it has been carried forward without much theoretical direction. So much research has been done in the field, however, that possibly a tentative general theory for further work may now be advanced. To be useful, an historical hypothesis should probably center on some common denominator of human experience. One possible common denominator is that all men are located within, or are a certain definite distance from metropolitan unit. All those who live within a certain given zone around the metropolis have at least one common experience: they are all some specific distance from the metropolis. Furthermore, for any given group of people this one common experience may have shaped many of their ideas and actions. Since human events take place in time and space, a theory based primarily on these dimensions might be at least roughly applicable to most history.
Adsorption and ordering of oxygen on Cu(110)

XPS and LEED were used to study the adsorption and ordering of oxygen on Cu(110) at 83 +/- 1 K and between 300 and 320 K and to follow changes in the oxygen coverage and surface structure produced by 5-min anneals at temperatures up to 880 K. The relationship between oxygen coverage and surface structure, as well as their mutual dependence upon exposure, surface temperature at exposure, and subsequent annealing treatment, is discussed. 9 references, 4 figures.
Why Do Spouses Hide Income

Abstract This paper proposes a simplified model of intrahousehold decision making where cooperative and noncooperative behavior are not mutually exclusive. Individuals choose the optimal share of income they wish to devote towards cooperation, where income is pooled and allocated collectively, and towards noncooperation, where income is allocated independently. Using the example of joint saving as an area of household cooperation, this model shows how limited autonomy and bargaining power can interact to create incentives for individuals to hide income. This result provides theoretical support for the call to collect survey data separately from individuals rather than from household representatives.
A big role for small RNAs in HDL homeostasis

High-density lipoproteins play a central role in systemic cholesterol homeostasis by stimulating the efflux of excess cellular cholesterol and transporting it to the liver for biliary excretion. HDL has long been touted as the “good cholesterol” because of the strong inverse correlation of plasma HDL cholesterol levels with coronary heart disease. However, the disappointing outcomes of recent clinical trials involving therapeutic elevations of HDL cholesterol have called this moniker into question and revealed our lack of understanding of this complex lipoprotein. At the same time, the discovery of microRNAs (miRNAs) that regulate HDL biogenesis and function have led to a surge in our understanding of the posttranscriptional mechanisms regulating plasma levels of HDL. Furthermore, HDL has recently been shown to selectively transport miRNAs and thereby facilitate cellular communication by shuttling these potent gene regulators to distal tissues. Finally, that miRNA cargo carried by HDL may be altered during disease states further broadened our perspective of how this lipoprotein can have complex effects on target cells and tissues. The unraveling of how these tiny RNAs govern HDL metabolism and contribute to its actions promises to reveal new therapeutic strategies to optimize cardiovascular health.
Effects of atrial fibrillation substrate and spatiotemporal organization on atrial defibrillation thresholds.

Background We previously showed that canine models of atrial fibrillation (AF) have different substrates (either structural or electrical) that lead to differences in AF characteristics. Objective The purpose of this study was to determine whether the differences in AF characteristics also would lead to differences in atrial defibrillation thresholds (ADFTs). Methods Dogs were divided into five groups: control; MR—mitral regurgitation for 5 weeks; CHF—congestive heart failure for 4 weeks; RAP—rapid atrial pacing for 6 weeks; and METH—acetyl–β–methylcholine acutely administered. A cross-sectional area of the left atrium was calculated, and AF was induced with rapid atrial pacing. Biphasic shocks with a pulse width of 3/3 ms were delivered through specially constructed shocking catheters with a surface area of 3.7 cm 2 that were placed in the right and left atria. An up–down–up protocol was used to determine the 50% ADFT threshold (ADFT 50 ). A wide-bipole AF signal was digitally filtered, and a fast Fourier transform was calculated over a 2-second window every 1 second. The dominant frequency was determined, and the organization index was calculated as the ratio of the area under the dominant peak and its harmonics to the total area of the spectrum. Results For left atrial size, the CHF and MR groups had a significantly larger atria than did control. ADFT 50 for control, MR, CHF, RAP, and METH groups were 160 ± 30 V, 120 ± 50 V, 132 ± 20 V, 668 ± 205 V, and 593 ± 128 V, respectively (analysis of variance, P Conclusion RAP and METH canine models had a significantly higher ADFT 50 compared with the other AF models. The increase in ADFT 50 in these models corresponded with higher global dominant frequencies and lower measured organization indexes.
Diazepam withdrawal: effects of diazepam and gepirone on acoustic startle-induced 22 kHz ultrasonic vocalizations.

It has proven difficult to demonstrate and study the “anxiogenic” quality of drug withdrawal states in animals. Ultrasonic vocalizations (USV) in response to acoustic startle stimuli have shown promise as a measure of affect and may represent “distress” responses during diazepam withdrawal. Three experiments evaluated the association between USV and “distress” by comparing the effects of diazepam as a prototypic benzodiazepine agonist and the putative anxiolytic gepirone with affinity for 5-hydroxytryptamine (5-HT1A) receptors in naive and diazepam-withdrawn subjects. Adult male Long-Evans rats were exposed to acoustic startle sessions consisting of nine 105 dB and nine 115 dB stimuli. USV at 20–30 kHz were readily emitted during startle and often commenced after the third or fourth stimulus presentation. Acutely, intraperitoneal (IP) administration of diazepam (0.1–3 mg/kg) and gepirone (0.1–1 mg/kg) decreased USV dose-dependently without affecting the startle reflex; gepirone also decreased tail flick latency. Startle-induced USV were also sensitive to the “anxiogenic” effects of withdrawal from diazepam exposure (0, 2.5, 5, 10 mg/kg b.i.d. IP×5 days). Twenty-four hours after the last diazepam injection, rats were hyperreactive to startle stimuli and doubled their rate of USV over vehicle-treated controls. Gepirone (0.1–1 mg/kg IP), but not diazepam (3–20 mg/kg IP) antagonized the increased rate of USV in rats withdrawn from 10 mg/kg b.i.d. diazepam. Diazepam (2.5–10 mg/kg IP) antagonized the increased rate of USV in rats withdrawn from 2.5 mg/kg b.i.d. diazepam. USV induced by acoustic startle stimuli are sensitive to the anxiolytic effects of benzodiazepine and 5-HT1A receptor agonists and permit the assessment of the “anxiogenic” properties of diazepam withdrawal. The potent effect of gepirone on USV suggests a serotonergic amelioration of the “anxiogenic” aspects of diazepam withdrawal.
Antidromic reciprocating tachycardia: What is the mechanism of termination?

Q c n A t m t i p t i ase presentation lectrophysiologic study was performed in a 24-year-old oman with Wolff-Parkinson-White syndrome who preented with a preexcited, regular tachycardia that terminated ith adenosine. The polarity of the delta wave was positive waves in eads I and aVL, negative in III and aVF, and isoelectric in I. The precordial transition occurred in V3. In the baseline tate, there was no ventriculoatrial conduction. Anterograde ccessory pathway (AP) conduction was decremental, with block cycle length of 370 ms. On isoproterenol, ventriculoatrial conduction was midine and decremental, with the earliest atrial activation in he proximal coronary sinus, consistent with conduction hrough the AV node. The anterograde block cycle length of he AP was 310 ms. Antidromic reciprocating tachycardia ith a cycle length of 315 to 325 ms was induced by entricular extrastimulus testing. There was no evidence of second AP. The tachycardia terminated spontaneously on everal occasions in a reproducible fashion (Figure 1). What s the mechanism of termination?
Neuroendocrine plexus in the pericardial septum of the stable fly, stomoxys calcitrans (L.) (diptera : muscidae)☆

Abstract An ultrastructural study of the pericardial septum (dorsal diaphragm) of the stable fly revealed that it consists of a central band of longitudinal muscle fibers upon which the paired alary muscles attach. A new neurohemal site was discovered that extends the length of the pericardial sinus. The neurosecretory axons terminating in this site originate from the segmental nerves. These nerves are also the source of axons that form 4 morphological types of neurosecretomotor junctions with the longitudinal muscle of the pericardial septum. Since the heart of the stable fly is myogenic, the neurohormones released into this septum may modulate the activity of the heart and/or be available for circulation to other sites of activity in this insect.
Reduction of CCl4 to the trichloromethyl radical by lignin peroxidase H2 from Phanerochaete chrysosporium.

Abstract We were able to spin trap the trichloromethyl radical withPBN in a reaction mixture containing lignin peroxidase H2, H 2 O 2 , CCl 4 , veratryl alcohol and EDTA. Upon removal of CCl 4 , EDTA radicals were detected. Based on a previously reported study (Shah et al., 1992, J. Biol. Chem. 267, 21564-21569), we propose that the oxidation of EDTA to EDTA derived radicals is mediated by the veratryl alcohol cation radical, and the reduction of CCl 4 to the trichioromethyl radical is caused by the EDTA derived radicals. The novel finding here is that CCl 4 , which is neither a substrate for the enzyme nor a good reductant, is degraded via free radicals generated by lignin peroxidases under reducing conditions.
Online algorithms with stochastic input

The design and analysis of online algorithms, where the input to the algorithm is revealed over time and the algorithm has to make decisions immediately without knowing the future input, has received a revived interest in the last few years primarily due to their application to online advertising. The canonical problem is the Adwords problem, which is motivated by the problem of optimally allocating ad slots on search queries to budget constrained advertisers. It involves simplifications that ignore certain aspects of the actual way this allocation is done. For instance, it assumes a "first-price" pay-per-impression scheme, ignoring the game theoretic aspects, and considers only one slot per query. To be precise, the Adwords problem is as follows.
Use of Carboprost to Facilitate Hysteroscopic Resection of Submucous Myomas

Ten women with submucous myomas that could not be completely resected hysteroscopically were treated with intracervical carboprost. This caused uterine contraction and extrusion of the unresectable intramural component into the endometrial cavity. Eleven of 13 myomas in these patients could then be completely resected. One intramural myoma extruded into the endometrial cavity after injection of carboprost and was also completely resected.
Synthesis and characterization of the monomer Ga{(NDippCMe)2CH} (Dipp = C6H3Pri2-2,6): a low valent gallium(I) carbene analogue

The reaction between solvent free Li{(NDippCMe)2CH} (Dipp = C6H3Pri2-2,6), ‘GaI’ and potassium in toluene afforded Ga{(NDippCMe)2CH} 1 which features a V-shaped, two-coordinate, six-electron gallium(I) center electronically analogous to a singlet carbene carbon.
Atomic-beam measurements of helium F-G, F-H, and F-I intervals

The fast-atomic-beam microwave-optical resonance technique has been used to measure the 8F-8G, 8F-8H, 7F-6H, and 7F-7I intervals in helium. The electrostatic fine-structure intervals derived from these measurements and from theoretical values of the magnetic fine structure are 8F-8G, 3898.525(0.041); 8G-8H, 931.34(0.44); 7G-7H, 1359.16(0.11); and 7H-7I, 402.8(4.7) MHz. Additional theoretical work is needed to understand these intervals beyond the 1% level.
Stability in L systems

Abstract Given an L System G , a word w is said to be k -stable in G if, once w occurs in a derivation, the derivation can proceed no more than k steps before the next occurence of w . The set of k -stable words in an L System is called the k -stable language of the system. The k -stable languages of the main classes of L Systems are characterized by the Adult languages of the corresponding classes. This work provides a new characterization of the Chomsky hierarchy in terms of totally parallel grammars, and some consequences of this characterization are explored.
New insights into the regulation and functions of Tec family tyrosine kinases in the immune system.

The Tec family of protein tyrosine kinases play an important role in signaling through antigen-receptors such as the TCR, BCR and Fce receptor. Recent studies have generated new insights into the domains in Tec kinases that take part in intramolecular and intermolecular binding. Furthermore, the consequences of these domain interactions for Tec activation and downregulation have been better defined. Genetic studies of kinase-knockout mice have emphasized the importance of Tec kinases in lymphocyte development, differentiation and apoptosis.
Advocacy on the Internet: Lessons Learned from the Animal Enterprise Terrorism Act of 2005

After the Animal Enterprise Terrorism Act (AETA) was introduced to Congress in 2005, animal rights organizations joined efforts to advocate against the legislation. Their efforts failed even though more than 250 groups across the nation joined together to lobby against the act. To evaluate the communication strategies and media relations efforts of these organizations, a content analysis of randomly sampled advocacy group Web sites was conducted. Of the 122 “Stop AETA” organizations in the sample, 82% had a Web site though only 36% of those organizations with Web sites had organized online press rooms to promote their causes. This paper examines the implications of advocacy communication in a virtual environment and recommends strategies for improving the media relations efforts.
The formation and destruction of aromatic compounds in a turbulent flame

Systematic, detailed studies of the effects of temperature and fuel type on polycyclic aromatic compound (PAC) emissions from turbulent flames were carried out in a well-controlled, pilot-scale turbulent flame. Benzene and toluene were injected as a secondary fuel into the hot combustion products of a fuel-lean natural gas air flame at 1350 and 1550 K. The experimental results show a strong combined influence of fuel type and temperatureon the PAC emissions. At 1350 K, the PAC yield was approximately 10 times higher than that of soot, while at 1550 K, the soot yield was 10 times higher than the PAC yield, indicating a much faster formation and conversion to soot of PACs. At the higher temperature, the product distribution of PACs shifted toward species containing cyclopenta-fused rings. At 1550 K, the fuel type had virtually no impact on either the total yield of PACs and soot or the product distribution, while at the lower temperature, a large difference in yield and product distribution were found between the experimental fuels. At 1350 K, toluene injection produced up to 25 times more PACs and 30 times more soot than the injection of benzene. Also, the peak concentrations of soot and PACs in the benzene flame occurred later than in the toluene flame. A numerical model based on a segregated flow analysis was used to quantitatively analyze the experimental data. The treatment of the experimental flames by the model showed that the PAC emissions from the flames were affected by both chemistry and mixing. The model correctly predicted the trends of formation, and destruction of most compounds included in the model, and the absolute concentrations of individual species vary from within a factor of 5 (for major species) to within two orders of magnitude (for trace pollutants).
Symmetry of the H Center in KCl and KBr

$H$ centers were produced in KCl and KBr by x-irradiation at temperatures near liquid helium. The symmetry of these centers was determined by observing the dichroism produced in the absorption band after bleaching with polarized $H$-band light. It was found that the optical dipole moment of the $H$ center is parallel to $〈110〉$. The polarized bleaching light tends to reorient the $H$ centers as well as to bleach them. The oscillator strength of the $H$ center was found to be greater than about 0.3 that of the $F$ center in KCl and greater than about 0.5 that of the $F$ center in KBr.
Case Log Review Produces Translational Change in Surgical Oncology Education

Abstract Background. The recently mandated reduction in surgical resident work hours led to concerns that surgical cancer education would suffer, as measured by cancer case exposure. Methods. Final operative logs submitted to the American Board of Surgery by chief residents graduating from our program were compared for 2 time periods: prior to the mandate (2002-2003) and after (2006-2007). Results. Case logs from graduating residents (n = 36) showed a nonsignificant decrease in cancer as the percentage of total major cases, due to an actual increase in total major cases. Conversely, endoscopy and minor cancer case experience both decreased. Conclusions. Exposure to minor cancer cases and endoscopies has decreased; this has led to a reuirment for a minimum number of endoscopies/graduatingresident, and to strategies for increasing exposure to minor cancer cases.
Lipid composition of the pecan weevil,Curculio caryae (Horn)

The lipids of larvae, male adults, and female adults of the pecan weevil,Curculio caryae (Horn), were studied, and special attention was given the fatty acid composition. The larvae contained an unusually high amount of lipid material (40.6%), most of it concentrated in the neutral lipid fraction. Male and famale adults contained more conventional quantities, 5.8 and 8.2%, respectively. Oleic acid was the major fatty acid in the total and neutral lipids of all stages; linoleic acid was the most abundant in the phospholipid fractions.
Antiepileptic drugs and bone disease

Numerous studies have provided evidence of an association between antiepileptic drugs (AEDs) and adverse effects. Manifestations of bone disease in persons treated with AEDs include rickets, osteomalacia, osteoporosis, and fracture. There exists pathological and radiographic evidence of bone disease in persons with epilepsy treated with AEDs. As well, numerous biochemical abnormalities have been described including hypocalcemia, hypophosphatemia, reduced levels of biologically active vitamin D metabolites, hyperparathyroidism, and accelerated bone turnover, as measured by markers of bone formation and bone resorption. The AEDs most commonly reported as affecting bone include inducers of the cytochrome P450 enzyme system (phenytoin, phenobarbital, primidone, carbamazepine). In addition, there is growing evidence to suggest that valproate, an enzyme inhibitor, also affects bone. Limited data exists regarding the newer AEDs. Several mechanisms for AED-associated bone disease have been proposed, but no single mechanisms adequately addresses all the reported findings. Reported mechanisms include hepatic induction of the cytochrome P450 enzyme system leading to increased catabolism of vitamin, impaired absorption of calcium, inhibition of response to parathyroid hormone, hyperparathyroidism, impaired bone resorption and formation, vitamin K deficiency, and calcitonin deficiency. Few studies have evaluated the effect of treatment in bone disease associated with AEDs.