cssi/SciSciGPT-SciSciNet huggingface dataset:
Radio science issues surrounding HF/VHF/UHF radar meteor studies

Abstract Classical meteor radars depend on coherent (Fresnel) scattering from a meteor trail oriented perpendicular to the radar wave vector at closest approach to the radar. Meteor trails viewed in this manner are described as “classical” radar meteors with under/over-dense trails. While meteor “head-echoes” are rarely seen with classical low-power, wide-beam HF meteor radars, they are essentially always seen by large aperture (narrow-beam), high-power VHF/UHF radars. We discuss the expected radar scattering cross-sections (RCSs) of head-versus trail-echoes and how equilibrium concepts such as plasma frequency are of limited use in describing the results. Particular attention is given to the frequency dependence of the RCS and how the frequency dependence may yield considerable new information regarding the plasma distribution in the “coma” surrounding the meteoroid. As the head-echo is directly associated with the meteoroid, instantaneous (single-pulse) Doppler observations are possible. In the case of classical trail-echoes, the time evolution of the RCS as a function of frequency may provide new information on the plasma diffusion rate and thus on atmospheric density and temperature. Information from the time evolution of the trail must however be considered in light of new results showing that the trail rapidly B-field-aligns in a manner apparently driven by plasma instabilities that develop in 10– 100 ms after trail deposition. It is in the context of instability-driven B-field alignment of the trails that we discuss anomalous trail-echoes. The anomalous trail-echo is a range-spread chaotic (non-classical) trail-echo derived from a meteor that travels at an arbitrary angle relative to the radar wave vector. We present theoretical simulations illustrating these concepts.
Mitochondrial processing of newly synthesized steroidogenic acute regulatory protein (StAR), but not total StAR, mediates cholesterol transfer to cytochrome P450 side chain cleavage enzyme in adrenal cells.

The metabolism of cholesterol by cytochrome P450 side chain cleavage enzyme is hormonally regulated in steroidogenic tissues via intramitochondrial cholesterol transport. The mediating steroidogenic acute regulatory protein (StAR) is synthesized as a 37-kDa (p37) precursor that is phosphorylated by protein kinase A and cleaved within the mitochondria to generate 30-kDa forms (p30, pp30). The effectiveness of modified recombinant StAR forms in COS-1 cells without mitochondrial import has led to a prevailing view that cholesterol transport is mediated by p37 StAR via activity on the outer mitochondrial membrane. The present study of the activation of cholesterol metabolism by bromo-cAMP in adrenal cells in relation to35S-StAR turnover indicates that targeting of pp30 to the inner membrane provides the dominant cholesterol transport mechanism. We show that 1) only newly synthesized StAR is functional, 2) phosphorylation and processing of p37 to pp30 occurs rapidly and stoichiometrically, 3) both steps are necessary for optimum transport, and 4) newly synthesized pp30 exhibits very high activity (400 molecules of cholesterol/StAR/min). Segregation of cAMP activation and synthesis of StAR from cholesterol metabolism showed that very low levels of newly synthesized StAR (1 fmol/min/106 cells) sustained activated cholesterol metabolism (0.4 pmol/min/106 cells,t 1/2 = 70 min) long after complete removal of p37 (t 1/2 = 5 min). This activity was highly sensitive to inhibition of processing by CCCP only until sufficient pp30 was formed. Maximum activation preceded bromo-cAMP-induced StAR expression, indicating other limiting steps in cholesterol metabolism.
A novel open field activity detector to determine spatial and temporal movement of laboratory animals after injury and disease

The wide range of tests for laboratory animal behavior after neurological injury or disease each have their benefits and detriments. The varied behavior an animal exhibits makes it difficult to decide which test to use. However, a fundamental instinct for the laboratory animal is to explore when placed in a new environment. A way to test exploratory behavior is in the open field. Here, we introduce a simple activity box without the use of video equipment to determine the exploratory movement of a rat after traumatic brain injury. The activity box is an open field and the rat explores its surroundings when placed inside. Four infrared beams were placed in both the X and Y-axis inside the box. Using a novel system to determine which beam the rat breaks, we describe where the rat is in space and time while in the activity box. Other models can show the number of beams broken, but here we elucidate the methods to additionally determine the amount of area explored, the total distance traveled by the rat and percent time exploring.
Residual Strength and Corrosion Rate Predictions of Aging Aircraft Panels: Neural Network Study

The strength of an aging aircraft component deteriorates mainly as a result of corrosion and fatigue damage, among other failure mechanisms. Corrosion causes loss of material thickness, and the fatigue reduces the strength asa resultofdamageatmultiplesitesin aging aircraft. Thispaperpresentsa neural network study of both residual strength and corrosion of aging aircraft panels. Theresults obtained from theneural network model are compared to the analytical and experimental data available in the literature. The results obtained indicate that the neural network model predictions are in good agreement with the experimental data. To demonstrate the utility of neural network, several simulations are carried out to predict the trends with varying input parameters. Nomenclature a1 = MSD crack length measured from center of hole a2 = half-crack length of lead crack b = ligament length d = average diameter of the hole L = average MSD crack length measured from hole edge n = number of holes with MSD cracks Pc = critical load R = hole radius Dd=2 t = specimen thickness W = specimen width ± = hole spacing
On the origin of orogenic volcanism

It is widely believed that the explanation of orogenic volcanism lies in the shear heating and subsequent partial melting of the crustal fraction of subducted lithosphere. Careful examination of simple models of the shear-heating process indicates, however, that this process cannot occur in a system with constant strain-rate boundary conditions, for reasonable values of the strain rate and material parameters. Thermal runaway cannot occur because viscous dissipation process is limited by the effect of temperature on viscosity, although shear-heating instability may develop during non-steady-state shear at stress or strain-rate values above certain critical values. Examination of subduction history models indicates that supercritical shear stresses constant over some tens of kilometers may be found in subduction shear zones. Since instability may develop if such conditions are present over even a 1–10 km range, it is still possible that non-steady-state process could explain the origin of orogenic volcanism.
Genetic implications of broodstock selection for crayfish aquaculture in the Midwestern United States

Abstract The commercial culture of crayfish has recently gained popularity in many regions of the United States. This popularity has led to the development of culture strategies in several Midwestern states, where a number of crayfish species are being examined in order to determine those best for culture in this region. Some crayfish species seem better adapted to the climactic conditions of the Midwest, and therefore perform better in an aquaculture setting than others. The reasons for these differences may be connected to genetic variability. However, the extent of genetic variation both within and among crayfish species is not well known. We examined genetic variation within and among populations of the Northern ( Orconectes virilis ) and White River ( Procambarus acutus acutus ) crayfishes using protein electrophoresis. Allele frequencies are reported for four populations of O. virilis and P. a. acutus and single populations of O. nais and O. immunis . Among the O. virilis populations, significant variation in allele frequencies was observed at several loci, and fixed allelic differences were detected at three loci. P. a. acutus populations also exhibited a similar diversity of allele frequencies, and these differences appear related to geography. This study demonstrates that O. virilis and P. a. acutus are genetically heterogeneous, even over relatively small geographic distances. Intraspecific genetic variability in crayfish appears to be quite extensive and should be considered by aquaculture specialists when selecting brood stocks. Therefore, we recommend that local stocks be chosen for aquaculture operations commencing in the Midwest and that the introduction of non-native species (or populations) be limited in order to conserve native crayfish gene pools.
Hot QED in a big box. Implications for anomalous baryon nonconservation

Abstract Chiral charge in (3 + 1)-dimensional finite temperature QED does not relax to zero, even though it can fluctuate at high temperature. There is a conserved, gauge invariant chiral charge in QED which is related to linking number. We discuss the connection with some recent arguments relating the relaxation rate to the fluctuation rate for baryon number in the standard model.
ORGANIZING RIGHTS AT THE “GLOBAL UNIVERSITY”

This article explores the global dimension of the fight for organizing rights among graduate teachers and researchers in private universities, focusing on the fight at Yale, but contextualizing that campaign in a new and developing national movement for academic organizing rights. The global image of one university and the reality of the global academic workforce are examined. A key element of the research is the documentation of the emerging national movement for the rights of international academic workers through graduate teacher union organizing at Yale University. This article provides historical examinations of the Chinese students in the graduate student union at Yale and of the factors leading to the emergence of a broader consciousness of labor rights in the academy.
Least-squares forecast averaging

Abstract This paper proposes forecast combination based on the method of Mallows Model Averaging (MMA). The method selects forecast weights by minimizing a Mallows criterion. This criterion is an asymptotically unbiased estimate of both the in-sample mean-squared error (MSE) and the out-of-sample one-step-ahead mean-squared forecast error (MSFE). Furthermore, the MMA weights are asymptotically mean-square optimal in the absence of time-series dependence. We show how to compute MMA weights in forecasting settings, and investigate the performance of the method in simple but illustrative simulation environments. We find that the MMA forecasts have low MSFE and have much lower maximum regret than other feasible forecasting methods, including equal weighting, BIC selection, weighted BIC, AIC selection, weighted AIC, Bates–Granger combination, predictive least squares, and Granger–Ramanathan combination.
Neuronotrophic factors and their antibodies: in vitro microassays for titration and screening.

Summary Using nerve growth factor (NGF), anti-NGF sera and dissociated neonatal mouse dorsal root ganglionic neurons we present a microculture assay methodology for (1) the titration of neuronotrophic factor (NTF) activity in monolayer culture, (2) the titration of NTF antibodies which ‘block’ NTF biological activity, (3) the titration of NTF antibodies that bind and remove (sequester) NTF from culture medium and (4) a large-scale, convenient, and rapid screening for NTF biological activity as well as for NTF ‘blocking’ or ‘sequestering’ antibodies. These quantitative and qualitative in vitro microimmunoassays should be applicable to any neuronotrophic factor or its antibody, even when the agent is only available in crude, unpurified form. Since the microculture systems permit the simultaneous screening of one thousand samples per day they should be useful for the detection and quantitation of monoclonal antibodies present in hybridoma-conditioned media.
Finding those at risk: Acute HIV infection in Newark, NJ

Background A screening strategy combining rapid HIV-1/2 (HIV) antibody testing with pooled HIV-1 RNA testing increases identification of HIV infections, but may have other limitations that restrict its usefulness to all but the highest incidence populations.
An investigation of the relationship between uniaxial compressive strength and degradation for selected rock types

Abstract The relationship between uniaxial compressive strength and degradation was investigated for selected rock types, by using regression analyses to determine whether degradation was a useful predictor of compressive strength. In addition, the effects of aggregate particle size, number of hammer blows during the degradation test, engineering index properties, petrographic characteristics, and water saturation on the compressive strength-degradation relationship were evaluated. The results show that strong inverse relationships exist between compressive strength and degradation (measured on a 9.5-4.75-mm size aggregate) for sandstones and igneous/metamorphic rocks, but that no significant relationship exists for limestones/dolomites. The results also indicate a strong positive correlation between degradation and L.A. abrasion loss and can be used to establish a limit of allowable degradation for practical applications. Engineering index properties do not significantly affect the relationship between compressive strength and degradation but petrographic characteristics are important in explaining the strength and degradation behavior of the rocks studied. Water saturation decreases compressive strength and increases degradation to varying degrees.
Immobilized IgG and fibrinogen differentially affect the cytoskeletal organization and bactericidal function of adherent neutrophils.

The infection of a vascular prosthesis is a dreaded clinical outcome. Since fibrinogen (FBGN) and immunoglobulin (IgG) coat the implanted biomaterial surface, it is with these immobilized proteins that the neutrophil (PMN) interacts. This study tests the hypothesis that PMN are impaired in their ability to kill bacteria when bound to immobilized IgG or FBGN. Isolated human PMN were bound to FBGN or IgG and then left untreated or exposed to phorbol myristate acetate (PMA; 10−7M). PMN adhered loosely, but did not spread, onto FBGN. In contrast, PMN spread fully onto IgG, exhibiting polarized pseudopodia. PMA treatment induced spreading of the FBGN bound cells. Suspended and adherent PMN were incubated 1 h with14C-labeledStaphylococcus aureus;then, phagocytosis was assessed by radioactive uptake or bacterial kill was determined by plating recovered bacteria and colony counting. Data were analyzed by unpairedttest. We observed that both the phagocytic and the killing ability of FBGN-bound PMN were similar to that of suspended PMN. Conversely, IgG-bound PMN displayed a 62 ± 6% (P< 0.01) decrease in phagocytosis and 33 ± 7% (P< 0.05) reduction in kill vs suspended cells. PMA induced a 74 ± 6% (P< 0.01) reduction in phagocytosis and 68 ± 5% (P< 0.01) reduction in kill of bacteria for PMN bound to FBGN with no further effect on IgG-bound PMN. Using fluorescent vital dyes and confocal microscopy we determined that 33% fewer PMN were engaged in phagocytosis when bound to IgG vs FBGN. We conclude that Fc receptor ligation by immobilized IgG or PMA treatment of the FBGN-adherent PMN triggers cell spreading and reduced bactericidal activity. These results indicate that excessive cytoskeletal organization may impair the ability of PMN to kill bacteria and result in vascular graft infections.
M4 mAChR-mediated modulation of glutamatergic transmission at corticostriatal synapses.

The striatum is the main input station of the basal ganglia and is extensively involved in the modulation of motivated behavior. The information conveyed to this subcortical structure through glutamatergic projections from the cerebral cortex and thalamus is processed by the activity of several striatal neuromodulatory systems including the cholinergic system. Acetylcholine potently modulates glutamate signaling in the striatum via activation of muscarinic receptors (mAChRs). It is, however, unclear which mAChR subtype is responsible for this modulatory effect. Here, by using electrophysiological, optogenetic, and immunoelectron microscopic approaches in conjunction with a novel, highly selective M4 positive allosteric modulator VU0152100 (ML108) and M4 knockout mice, we show that M4 is a major mAChR subtype mediating the cholinergic inhibition of corticostriatal glutamatergic input on both striatonigral and striatopallidal medium spiny neurons (MSNs). This effect is due to activation of presynaptic M4 re...
Fuzzy web information retrieval system with fuzzy thesaurus using fuzzy relational BK-products

This study develops a web information retrieval system using the fuzzy relations in the indexing and ranking portions of standard web retrieval methods. The system was developed, including crawler, indexer, ranking portion, and user search structure. The BK-products of fuzzy relations with closure/interior properties are used to construct a fuzzy thesaurus and further to retrieve the relevant documents. The results of the system are evaluated and compared with the existing search methods.
Structures of Bacteroides fragilis uridine 5′-diphosphate-N-acetylglucosamine (UDP-GlcNAc) acyltransferase (BfLpxA)

Uridine 5′-diphosphate-N-acetylglucosamine (UDP-GlcNAc) acyltransferase (LpxA) catalyzes a reversible reaction for adding an O-acyl group to the GlcNAc in UDP-GlcNAc in the first step of lipid A biosynthesis. Lipid A constitutes a major component of lipopolysaccharides, also referred to as endotoxins, which form the outer monolayer of the outer membrane of Gram-negative bacteria. Ligand-free and UDP-GlcNAc-bound crystal structures of LpxA from Bacteroides fragilis NCTC 9343, the most common pathogenic bacteria found in abdominal abscesses, have been determined and are presented here. The enzyme crystallizes in a cubic space group, with the crystallographic threefold axis generating the biological functional homotrimer and with each monomer forming a nine-rung left-handed β-helical (LβH) fold in the N-terminus followed by an α-helical motif in the C-terminus. The structure is highly similar to LpxA from other organisms. Yet, despite sharing a similar LβH structure with LpxAs from Escherichia coli and others, previously unseen calcium ions are observed on the threefold axis in B. fragilis LpxA to help stabilize the trimeric assembly.
Precise measurement of methane in air using diode-pumped 3.4-μm difference-frequency generation in PPLN

volume multi-pass absorption cell with an 18-m path length. The methane mixing ratio was determined by comparing the direct optical absorption measured in the sample with that measured in a reference gas at 100 torr and room temperature. Relative accuracy of better than 1 ppb (parts in 109, by mole fraction) was achieved in measurements of natural air that contained 1700–1900 ppb methane. The typical measurement time for each sample was 60 seconds. The accuracy was limited by residual interference fringes in the multi-pass cell that resulted from scattering. Without the use of reference samples, the relative accuracy was 20 ppb; it was limited by the long-term reproducibility of the spectroscopic baseline, which was affected by drift in the optical alignment coupled to changes in the ambient temperature. This work demonstrates the use of diode-pumped difference-frequency generation (DFG) in PPLN in a high-precision infrared spectrometer. Compact, room-temperature solid-state gas sensors can be built based on this technology, for accurate real-time measurements of trace gases in the 3–5 μm spectroscopic region.
Smallest tournaments not realizable by $${\frac{2}{3}}$$-majority voting

Define the predictability number α(T) of a tournament T to be the largest supermajority threshold \({\frac{1}{2} < \alpha\leq 1}\) for which T could represent the pairwise voting outcomes from some population of voter preference orders. We establish that the predictability number always exists and is rational. Only acyclic tournaments have predictability 1; the Condorcet voting paradox tournament has predictability \({\frac{2}{3}}\); Gilboa has found a tournament on 54 alternatives (i.e. vertices) that has predictability less than \({\frac{2}{3}}\) , and has asked whether a smaller such tournament exists. We exhibit an 8-vertex tournament that has predictability \({\frac{13}{20}}\) , and prove that it is the smallest tournament with predictability < \({\frac{2}{3}}\) . Our methodology is to formulate the problem as a finite set of two-person zero-sum games, employ the minimax duality and linear programming basic solution theorems, and solve using rational arithmetic.
Thiazolidinediones Regulate Adipose Lineage Dynamics

Summary White adipose tissue regulates metabolism; the importance of this control is highlighted by the ongoing pandemic of obesity and associated complications such as diabetes, atherosclerosis, and cancer. White adipose tissue maintenance is a dynamic process, yet very little is known about how pharmacologic stimuli affect such plasticity. Combining in vivo lineage marking and BrdU labeling strategies, we found that rosiglitazone, a member of the thiazolidinedione class of glucose-lowering medicines, markedly increases the evolution of adipose progenitors into adipocytes. Notably, chronic rosiglitazone administration disrupts the adipogenic and self-renewal capacities of the stem cell compartment and alters its molecular characteristics. These data unravel unknown aspects of adipose dynamics and provide a basis to manipulate the adipose lineage for therapeutic ends.
Trends in intussusception-associated deaths among US infants from 1979-2007.

Objective We examined data from 1979-2007 to generate up-to-date baseline estimates of rotavirus intussusception mortality in US infants, to inform policy deliberations of the risks and benefits of vaccination. Study design Secular trends in the infant intussusception mortality rate were evaluated using national multiple cause-of-death and natality data from 1979- 2007. Linked birth/infant death data from 1998-2006 were examined to identify risk factors for intussusception deaths. Results After declining from 1979-1996, the average annual intussusception mortality rate stabilized from 1997-2007 at 2.1 per 1 million live births (range, 1.0-3.0). In multivariate analysis, significant variables associated with intussusception deaths included no prenatal care (OR, 5.4; 95% CI, 1.9-15.4) and birth order (≥3rd) (OR, 2.4; 95% CI, 1.4-4.4 [reference: birth order (1st)]). Conclusions Given the annual variation in intussusceptions mortality and low baseline rates, if a low vaccine-associated risk of death from intussusception exists in the United States, it would be difficult to assess using intussusception mortality trend data alone. Factors associated with intussusception mortality risk may be related to delayed or reduced health care access.
Age Differences in a Virtual Reality Entertainment Environment: A Field Study:

The data presented below was collected at a Virtual Reality (VR) amusement center in Orlando, FL. This study is exploratory, i.e., an initial attempt to try and uncover factor(s) that may interact ...
High performance level conversion for dual V/sub DD/ design

Multi-V/sub DD/ design is an effective way to reduce power consumption, but the need for level conversion imposes delay and energy penalties that limit the potential gains. In this paper, we describe new level converting circuits that provide 10%-61% lower energy consumption at equivalent or better speeds compared to those available in the literature. Furthermore, we make the argument that level converters should be evaluated largely by their maximum speed since slower level converters consume valuable timing slack that can be used to reduce the energy of other gates in the circuit. Based on this criterion, we find the new structures to offer up to a 25% speed improvement over conventional level converters. Using an efficient dual V/sub DD/ voltage assignment algorithm, we show that this speed improvement can yield a reduction of up to 7.3% in total circuit power in small benchmark circuits. We also propose embedding the functionality of logic gates into the level converting circuits. For typical values of the second supply voltage, this technique can reduce delay by 15% at constant energy or lower energy by up to 30% at fixed delay.
17β-Estradiol-mediated growth inhibition of MDA-MB-468 cells stably transfected with the estrogen receptor: Cell cycle effects

Abstract Estrogen receptor (ER)-negative MDA-MB-468 human breast cancer cells were stably transfected with wild-type human ER and utilized as a model for investigating estrogen- and aryl hydrocarbon (Ah)-responsiveness. Treatment of the stably transfected cells with 10 nM 17 β -estradiol (E2) resulted in a significant inhibition (>60%) of cell proliferation and DNA synthesis, which was blocked by 10 −7 M ICI 182 780. Analysis by flow cytometry indicated that treatment with E2 increased the percentage of cells in G0/G1 (from 68.8 to 89.4) and decreased cells in S (from 18.4 to 3.4) and G2/M (from 12.8 to 7.2) phases of the cell cycle. The effects of E2 on the major cyclins, cyclin-dependent kinases and cyclin-dependent kinase inhibitors, retinoblastoma protein (RB), E2F-1, and cyclin-dependent kinase activities were also investigated in the stably transfected MDA-MB-468 cells. The results demonstrated that the growth inhibitory effects of 10 −8 M E2 in ER stably transfected MDA-MB-468 cells were associated with modulation of several factors required for cell cycle progression and DNA synthesis, including significant induction of the cyclin-dependent kinase inhibitor p21 cip-1 (>4-fold increase after 12 h) and decreased E2F1 and PCNA protein levels. These results show that the growth-inhibitory effects of E2 in the stably transfected cells were due to multiple factors which result in growth arrest in G0/G1 and inhibition of DNA synthesis.
MICROFABRICATION METHODS FOR MICROCHANNEL REACTORS AND SEPARATIONS SYSTEMS

Abstract The fabrication of a microchannel chemical solvent separation unit and a microchannel chemical reactor is described. The performance of the solvent separation unit was enhanced by improved kinetic effects resulting from short liquid/liquid contact times in the device. These effects were exploited to allow preferential extraction of solute species from a fluid waste stream. The completed unit consisted of a series of microchannels separated by micromachined metal or polyimide membranes. Channel and membrane layers were produced from individual layers of type 304 stainless steel shim. Laser micromachining, photochemical machining, and photolithographic patterning were used to fabricate the individual layers. Flow channel width, height and length was 100 μm, 1 cm, and 8 cm respectively. The channels had an aspect ratio of 1000. The separation membranes consisted of an array of 5- μm to 30- μm-diameter micropores laser micromachined in polyimide or 130 μm diameter micropores machined through the stai...
Testing the Doran summer climate rules in Upper Wright Valley, Antarctica

Based on data from low elevation lake sites, previous studies have suggested three quantitative relationships related to summer (December, January and February) air temperatures in the Dry Valleys of Antarctica: i) decrease with altitude at the dry lapse rate of 9.8°C km-1, ii) increase with distance from the coast at a rate of 0.09°C km-1, and iii) degree-days above freezing during the summer months is logarithmically proportional to the maximum summer air temperature. Here, we tested the first two of these rules at high elevation sites in Upper Wright Valley. Direct measurements confirmed that the summer lapse rate followed the dry lapse rate. For the three furthest stations, Tyrol Valley, Mount Fleming and Horseshoe Crater, the average difference between the measurements and the predicted summer monthly averages are -2.1±1.4°C, -0.5±1.0°C and -0.4±0.9°C, respectively. By contrast, at Linnaeus Terrace (54 km from the coast) the monthly average is warmer than predicted by several degrees: +4.3±1.3°C. The inland temperature gradient at these high elevation sites may result from sunlight effects rather than coastal wind as previously shown for the lower valleys. The warm conditions observed c. 50 km from the coast may reflect a zone affected by both sunlight and coastal wind.
Inactivation of regulatory volume decrease in human peripheral blood lymphocytes by N-ethylmaleimide

Abstract The sulfhydryl group reagent N-ethylmaleimide was found to inhibit in a dose dependent manner regulatory volume decrease of human peripheral lymphocytes swollen in buffered hyposmotic NaCl media. In hyposmotic KCl media NEM treated lymphocytes prevented an additional secondary swelling seen in control lymphocytes. The data suggest that N-ethylmaleimide acts on ion transport mechanisms involved in volume regulatory changes. This effect contrasts with the stimulation by N-ethylmaleimide of apparently volume sensitive K Cl fluxes in certain mamalian red cells.
A Novel Nanostructured Open-Channel Coordination Polymer with an Included Fused-Polyiodide Ring

A novel three-dimensional nanostructured open-channel metal-organic framework polymer with inclusion of a polyiodide cluster has been synthesized via an oxidation reaction mechanism under hydrothermal conditions. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)
2-Amino-4-phosphonobutyric acid: A new pharmacological tool for retina research

Information processing in the vertebrate retina occurs in two separate channels known as ON and OFF channels. When intracellular electrophysiological recordings were obtained from the perfused retina-eyecup preparation of the mud-puppy (Necturus maculosus), the addition of 2-amino-4-phosphonobutyric acid to the bathing medium blocked all responses in the ON channel but left intact the OFF responses including OFF ganglion cell discharge. 2-Amino-4-phosphonobutyric acid blocks the light response of the ON bipolar cell by mimicking the endogenous photoreceptor transmitter.
Advancing in Your Career

AJR:197, September 2011 types of administrative posts, which the military has defined as “line” and “staff.” The former refers to a person who is in charge and in command, which is usually limited to one person in a section or department. Many more administrators in academia are in staff positions, advisory roles such as a departmental vice chair or an assistant or associate dean, which may be impressive titles lacking authority. These may be frustrating roles because there is responsibility without ultimate decision making. The additional effort required to rapidly ascend the academic ladder may include long working hours and extensive reading on relevant topics. For those on a research career track, attaining success will mean having to spend many nights and weekends writing significant scholarly articles for peerreviewed publications, (preferably in highimpact journals) and preparing applications for grant funding from prestigious organizations. You will want to be an active member and officer of your national and international subspecialty societies. You may need to devote substantial time to serve as a reviewer for the best professional journals, and as you advance, you will want to become a member of one or more editorial boards. Developing a major research academic career will require you to travel extensively to lecture at out-of-town conferences and other medical centers. As you rise in your career, you will be expected to serve as a mentor to residents, fellows, and young faculty, gaining recognition for their successes and accomplishments in the field. Career advancement may sometimes require frequent moves. All of these endeavors can take a toll on you and your significant others, and the road to the top requires real sacrifices by you and your family. Nevertheless, try to shelve job-related woes when you are at home. Smartphones, cell phones, and other such devices only creAdvancing in Your Career
The actinic keratosis. A perspective and update.

background Actinic keratosis (AK) is a common sun-induced precancerous neoplasm confined to the epidermis. It is the initial manifestation of a continuum of clinical and histologic abnormalities that progresses to invasive squamous cell carcinoma (SCO, a disorder that accounts for thousands of preventable deaths in America each year. objective The purpose of this work is to describe the actinic keratosis. methods This effort was performed by a literature review and analysis. results Like SCCs, the vast majority of AKs are asymptomatic. Although some actinic keratoses may become clinically inapparent, possibly cither due to immune rejection or simply having their external surface unknowingly scraped off, an untreated AK represents a potentially curable fatal cancer. conclusions Each AK should be treated before it progresses to invasive squamous cell carcinoma. Destructive modalities such as cryosurgery using liquid nitrogen and electrodesiccation and curettage are the mainstays of therapy. Each case must be individualized. learning objectives After studying this article, participant should be able to: 1 Understand the concept of an actinic keratosis. 2 Learn how to recognize its clinical manifestations. 3 Be aware of the danger it poses as an easily curable papulonodule that may become a fatal cancer.
Periphyton removal related to phosphorus and grazer biomass level

Summary 1. The proliferation of nuisance periphyton in enriched streams may be dependent on the biomass of the grazing macroinvertebrates present. In the present study, the effectiveness of grazer size and biomass in controlling periphyton and the extent to which grazing effectiveness was affected by enrichment level were determined. 2. Two sets of experiments with two caddisfly grazers were conducted in laboratory channels during spring and summer 1995 and 1996. The first set tested the combined effect of phosphorus enrichment and grazing, while the second set tested the effect of variable grazer biomass on periphyton biomass. 3. Grazing reduced periphyton biomass in excess of 80%, compared to ungrazed controls. Grazers were equally effective in controlling filamentous green algae, Stigeoclonium, diatoms and small colonial greens. Near complete removal of periphyton biomass by grazing occurred at even at the lowest grazer biomass level (750 mg m−−2, i.e. approximately one-third of natural levels). 4. Grazing controlled periphyton biomass more than did enrichment with soluble reactive phosphorus (SRP). 5. Grazing rates in the phosphorus-grazing interaction experiments averaged about 6 mg chl a g invertebrate−−1 day−−1, which was similar to past work in these channels and elsewhere, while rates were about five-fold higher in the variable grazer biomass experiments. 6. Simulating effects of SRP and grazing with a calibrated model suggests that higher SRP levels would be necessary to exceed a nuisance periphyton biomass level if grazers were present. However, if grazer biomass was more than 1500 mg m−−2, a nuisance level would probably not be exceeded at any SRP.
Harnessing collective intelligence in social tagging using Delicious

A new collaborative approach in information organization and sharing has recently arisen, known as collaborative tagging or social indexing. A key element of collaborative tagging is the concept of collective intelligence (CI), which is a shared intelligence among all participants. This research investigates the phenomenon of social tagging in the context of CI with the aim to serve as a stepping-stone towards the mining of truly valuable social tags for web resources. This study focuses on assessing and evaluating the degree of CI embedded in social tagging over time in terms of two-parameter values, number of participants, and top frequency ranking window. Five different metrics were adopted and utilized for assessing the similarity between ranking lists: overlapList, overlapRank, Footrule, Fagin's measure, and the Inverse Rank measure. The result of this study demonstrates that a substantial degree of CI is most likely to be achieved when somewhere between the first 200 and 400 people have participated in tagging, and that a target degree of CI can be projected by controlling the two factors along with the selection of a similarity metric. The study also tests some experimental conditions for detecting social tags with high CI degree. The results of this study can be applicable to the study of filtering social tags based on CI; filtered social tags may be utilized for the metadata creation of tagged resources and possibly for the retrieval of tagged resources. © 2012 Wiley Periodicals, Inc.
Cerebrospinal Fluid Response Following Metrizamide Myelography in Normal Dogs: Effects of Routine Myelography and Postmyelographic Removal of Contrast Medium

The effect of metrizamide myelography on 90-minute postmyelographic cerebrospinal fluid (CSF) samples was evaluated in a paired crossover study in 16 normal dogs. Each dog received a routine cervical myelogram (nonwithdrawal myelography) and a myelogram followed by contrast medium removal via aspiration from the subarachnoid space (withdrawal myelogram). Following nonwithdrawal myelography, the CSF was characterized by mild inflammation with a mixed pleocytosis and increased protein concentration. Compared with the nonwithdrawal CSF samples, the postmyelographic CSF of the withdrawal dogs had a more severe inflammatory response with significant increases (p < 0.05) in absolute numbers of neutrophils, monocytoid cells, eosinophils, lymphocytes, and protein concentration. The withdrawal procedure may have contributed an additional mechanical effect on the leptomeninges producing the more severe inflammatory response in the withdrawal dogs. Although seizure data are not reported here, postmyelographic seizures were more frequent following non-withdrawal myelography as compared with withdrawal myelography (p < 0.05), suggesting a decrease in metrizamide-induced neurotoxicity for the withdrawal dogs.
A low-profile, wideband, vertically-polarized antenna with directional radiation patterns in the azimuth plane

A low-profile, wideband, vertically-polarized antenna with directional radiation characteristics in the azimuth plane is proposed. The antenna is composed of four half-loops with the shape of bent diamond arms that are fed at the center and short circuited to the ground plane at their ends. Two of the loops are fed in phase and the other two are fed out of phase. Then, these two antenna arrays are fed using a proper feed network to obtain a cardioid-shaped radiation pattern over a very large bandwidth (6:1). The antenna has electrical dimensions of 0.77λ min × 0.77λ min × 0.09λ min at its lowest frequency of operation.
Identifying challenges of living with type 1 diabetes: child and youth perspectives.

Aims and objectives To identify challenges children and youth with type 1 diabetes encounter from their own perspectives. Background Type 1 diabetes requires lifestyle changes involving diet modification, monitoring blood glucose, counting carbohydrates and administering insulin. Learning self-care and developing positive attitudes can improve glucose management and promote long-term benefits. Therefore, understanding challenges of youth living with type 1 diabetes from their own perspective is an important first step in improving diabetes outcomes for this age group. Design Qualitative descriptive design using focus groups to identify the experiences and challenges of children and youth living with type 1 diabetes. Methods Six focus groups were held over a four-month period in 2010; each participant attended one focus group. A total of 16 children and youth with type 1 diabetes participated. The focus group discussions were audio recorded, transcribed verbatim and analysed for common themes according to qualitative methodology. To assure trustworthiness, investigators independently coded interviews and themes were refined and adjusted until consensus was reached. Results Three themes emerged after analysing transcripts from the focus groups that embody challenges children and youth with type 1 diabetes faced: (1) low blood glucose; (2) self-care activities; and (3) feeling different and/or alone. Conclusions Data indicated type 1 diabetes is challenging for this age group. These challenges must be addressed to assist youth in learning to manage their disease and promote healthy outcomes. Relevance to clinical practice It is important for nurses to discuss challenges, understand perspectives of this age group, listen to their concerns, work with them to develop strategies promoting health, minimise complications, reduce or eliminate feeling different or alone and assist parents' efforts to be supportive.
Effects of cations upon chloroplast membrane subunit interactions and excitation energy distribution

When isolated chloroplasts from mature pea (Pisum sativum) leaves were treated with digitonin under “low salt” conditions, the membranes were extensively solubilized into small subunits (as evidenced by analysis with small pore ultrafilters). From this solubilized preparation, a photochemically inactive chlorophyll · protein complex (chlorophyll ab ratio, 1.3) was isolated. We suggest that the detergent-derived membrane fragment from mature membranes is a structural complex within the membrane which contains the light-harvesting chlorophyll ab protein and which acts as a light-harvesting antenna primarily for Photosystem II. Cations dramatically alter the structural interaction of the light-harvesting complex with the photochemically active system II complex. This interaction has been measured by determining the amount of protein-bound chlorophyll b and Photosystem II activity which can be released into dispersed subunits by digitonin treatment of chloroplast lamellae. When cations are present to cause interaction between the Photosystem II complex and the light-harvesting pigment · protein, the combined complexes pellet as a “heavy” membranous fraction during differential centrifugation of detergent treated lamellae. In the absence of cations, the two complexes dissociate and can be isolated in a “light” submembrane preparation from which the light-harvesting complex can be purified by sucrose gradient centrifugation. Cation effects on excitation energy distribution between Photosystems I and II have been monitored by following Photosystem II fluorescence changes under chloroplast incubation conditions identical to those used for detergent treatment (with the exception of chlorophyll concentration differences and omission of detergents). The cation dependency of the pigment · protein complex and Photosystem II reaction center interactions measured by detergent fractionation, and regulation of excitation energy distribution as measured by fluorescence changes, were identical. We conclude that changes in substructural organization of intact membranes, involving cation induced changes in the interaction of intramembranous subunits, are the primary factors regulating the distribution of excitation energy between Photosystems II and I.
On the near field characteristics of axisymmetric turbulent buoyant jets in a uniform environment

Abstract A differential k-e- T′ 2 model is used to investigate the near field characteristics of buoyant jets discharging into a stagnant uniform environment. The lateral temperature and velocity profiles and the half width of turbulent buoyant jets in the zone of flow establishment are calculated. Also the mean centerline velocity and temperature decay, the turbulent kinetic energy and its dissipation rate are computed for a wide range of exit densimetric Froude numbers. A good agreement between the predicted and the available experimental data is obtained. The level of the turbulent fluctuations at the exit is found to have a strong influence on the jet characteristics in the near field region.
Passive broadband detection and identification of underwater targets and buried targets in "acoustic daylight"

In this paper, the author presents the recent results of passive Broadband Bionic Sonar System in the detection and identification of underwater targets in background noise, 'acoustic daylight'. Using a resonance detection technique, various underwater objects, cylinders and spheres of different sizes and different material compositions, were detected in acoustic backgrounds noise in Kaneohe Bay, Hawaii. In addition, bottomed and buried 3-inch diameter, stainless steel sphere targets were detected in background noise. The report presents the result of many passive broadband sonar experiments in acoustic background noise.
A retrospective case-controlled study of the association between request to discontinue second stage labor epidural analgesia and risk of instrumental vaginal delivery

Abstract Background Epidural dose is often reduced in the second stage of labor with the intention of improving maternal expulsive efforts and decreasing the need for instrumental vaginal delivery (IVD). We conjectured that parturients requiring IVD would have had more analgesic interventions and requests to decrease analgesic density in the second stage. Methods This retrospective, case-controlled study evaluated parturients with combined spinal-epidural analgesia and IVD over a 22-month period. Data recorded and compared between IVD and spontaneous delivery groups included requests to decrease the density of second stage analgesia and treatment of breakthrough pain. A model was developed from patient characteristics and analgesia interventions to predict the likelihood of IVD. Results Records from 2072 parturients were analyzed. The number of parturients in whom basal epidural infusion rate was decreased during the second stage of labor was greater in the IVD group (146/1021 (14.3%) vs. 51/1051 (4.9%), P Conclusion These results support an association between a request to reduce epidural dose in the second stage of labor, as well as supplemental analgesia for treatment of breakthrough pain, with IVD. It is unclear whether administration of more local anesthetic to treat breakthrough pain results in more dense motor blockade, and hence increases risk of IVD, or whether the decrease in infusion rate reflects obstetricians' dissatisfaction with the progress of obstructed labor.
Impaired Transition State Complementarity in the Hydrolysis of O-Arylphosphorothioates by Protein-Tyrosine Phosphatases†

The hydrolysis of O-arylphosphorothioates by protein-tyrosine phosphatases (PTPases) was studied with the aim of providing a mechanistic framework for the reactions of this important class of substrate analogues. O-Arylphosphorothioates are hydrolyzed 2 to 3 orders of magnitude slower than O-aryl phosphates by PTPases. This is in contrast to the solution reaction where phosphorothioates display 10−60-fold higher reactivity than the corresponding oxygen analogues. Kinetic analyses suggest that PTPases utilize the same active site and similar kinetic and chemical mechanisms for the hydrolysis of O-arylphosphorothioates and O-aryl phosphates. Thio substitution has no effect on the affinity of substrate or product for the PTPases. Bronsted analyses suggest that like the PTPase-catalyzed phosphoryl transfer reaction the transition state for the PTPase-catalyzed thiophosphoryl transfer is highly dissociative, similar to that of the corresponding solution reaction. The side chain of the active-site Arg residue f...