cssi/SciSciGPT-SciSciNet huggingface dataset:
Semiparametric methods for survival analysis of case-control data subject to dependent censoring

Case-control sampling can be an efficient and cost-saving study design, wherein subjects are selected into the study based on the outcome of interest. It was established long ago that proportional hazards regression can be applied to case-control data. However, each of the various estimation techniques available assumes that failure times are independently censored. Since independent censoring is often violated in observational studies, we propose methods for Cox regression analysis of survival data obtained through case-control sampling, but subject to dependent censoring. The proposed methods are based on weighted estimating equations, with separate inverse weights used to account for the case-control sampling and to correct for dependent censoring. The proposed estimators are shown to be consistent and asymptotically normal, and consistent estimators of the asymptotic covariance matrices are derived. Finite-sample properties of the proposed estimators are examined through simulation studies. The methods are illustrated through an analysis of pre-transplant mortality among end-stage liver disease patients obtained from a national organ failure registry. The Canadian Journal of Statistics 42: 365–383; 2014 © 2014 Statistical Society of Canada Resume L’echantillonnage cas-temoins peut constituer un plan d'experience efficace et economique dans le cadre duquel les sujets sont choisis pour l’etude en fonction du phenomene etudie. Il est etabli depuis longtemps que le modele de regression a risques proportionnels peut s'appliquer a des donnees cas-temoins. Cependant, toutes les techniques d'estimation existantes supposent que les temps de defaillance sont censures de facon independante. Etant donne que l'independance de la censure est souvent bafouee dans le cadre d’etudes observationnelles, les auteurs proposent des methodes pour la regression de Cox de donnees de survie sujettes a la censure dependante obtenues par un echantillonnage cas-temoins. Les methodes proposees se fondent sur des equations d'estimation ponderees dont les poids separes et inverses permettent de tenir compte de l’echantillonnage cas-temoins et de corriger le biais lie a la censure dependante. Les auteurs montrent que les estimateurs proposes sont convergents et asymptotiquement normaux. Ils obtiennent egalement des estimateurs convergents pour les matrices de covariance asymptotique. Ils examinent les proprietes de ces estimateurs sur des echantillons de taille finie par voie de simulation et illustrent les methodes au moyen d'une analyse de donnees sur le taux de mortalite pretransplantation chez les patients atteints d'une maladie hepatique en phase terminale provenant d'un registre national d'organes defaillants. La revue canadienne de statistique 42: 365–383; 2014 © 2014 Societe statistique du Canada
Comments on: “Understanding the Larson-Miller parameter”, by F. T. Furillo, S. Purushothaman and J. K. Tien (1)

The Larson--Miller parameter has been a useful tool in the handling of creep rupture data. Essentially, this is because, as an empirical scheme, it has so often been successful at correlating such data for a wide range of experimental conditions. Its use has proved invaluable to studies of nuclear fuel cladding embrittlement in reactor environments under diverse loading conditions. The kind of master plot that is generated through the use of this parameter is very helpful for predicting low stress-long time rupture behavior. The basic premise behind the success of the Larson--Miller method lies in the fortuitous elimination of one of the two independent variables that can be controlled during a creep test: the absolute temperature T and the applied stress sigma. When a test sample is stressed at temperature, it will fail after a time t/sub r/, depending upon the values of some unspecified, and usually unknown, material parameters. Larson and Miller (2) presented a simple expression involving these creep rupture variables which is only a function of the applied stress: LMP = T(C+log tr) = f(sigma). The quantity C is specified as a material constant, but is roughly 20 for a wide variety of commercial alloys. The eliminationmore » of the temperature dependence allows one to construct master rupture curves. This is the power of the Larson--Miller method. Once the function F(sigma) is determined graphically, regardless of its algebraic form, the stress is needed in order to know LMP. Knowing LMP, one can calculate t/sub r/ as a function of temperature. The paper under discussion does not serve to further an understanding of this useful empirical parameter. In fact, their derivation leads to a parameter similar in form to Larson and Miller's, except that it is a function of both stress and temperature, thereby defeating the purpose of the method.« less
Long-term follow-up of neck expansion after endovascular aortic aneurysm repair.

Objective This study determined the rate, extent, and clinical significance of neck dilatation after endovascular aneurysm repair (EVAR). Methods The study included 46 patients who underwent elective EVAR using bifurcated Zenith stent grafts (Cook, Bloomington, Ind) and had at least 48 months of clinical and radiographic follow-up. Computed tomography images were analyzed on a 3-dimensional workstation (TeraRecon, San Mateo, Calif). Neck diameter was measured 10 mm below the most inferior renal artery in planes orthogonal to the aorta. Nominal stent graft diameter was obtained from implantation records. Results Median follow-up was 59 months (range, 48-120 months). Neck dilation occurred in all 46 patients. The rate of neck dilation was greatest at early follow-up intervals. At 48 months, median neck dilation was 5.3 mm (range, 2.3-9.8 mm). The extent of neck dilation at 48 months correlated with percentage of stent graft oversizing (Spearman ρ = 0.61, P 5 mm occurred. Conclusions After EVAR with the Zenith stent graft, the neck dilates until its diameter approximates the diameter of the stent graft. Neck dilation was not associated with type I endoleak or migration of the stent graft.
FDG-PET in the Locoregional Lymph Node Staging of Non-small Cell Lung Cancer. A Comprehensive Review of the Leuven Lung Cancer Group Experience.

Exact staging of locoregional lymph node (LN) disease in non-small cell lung cancer (NSCLC) is of considerable clinical interest. Computed tomography (CT) is not very accurate for this purpose. In the past years, we performed several prospective studies examining the role of [18F]fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) in this setting. We compared the accuracy of CT, PET, and PET read with the anatomical aid of CT images in the distinction of early-stage operable cases (i.e., without metastatic LN or with only hilar metastatic LN) versus locally advanced cases (with metastatic mediastinal LN). LNs on PET were recorded as metastatic if the FDG-uptake was more intense than the mediastinal blood pool activity. In 105 patients (or an analysis of 980 LN stations), the accuracy of PET (85%) was significantly better than that of CT (64%; P = 0.0003). Visual correlation with CT images further improved the results to an accuracy of 90%. We also examined the value of different acquisition protocols and interpretation algorithms. The use of Standardized Uptake Values (SUVs) of LNs, or of anatometabolic PET-CT-fusion images, did not prove to be of additional value compared to visual PET-reading and correlation with the CT images. On the condition that positive-LN findings on PET are always confirmed by mediastinoscopy, a simple whole-body acquisition protocol is adequate. We conclude that FDG-PET plays an important role in LN-staging in NSCLC. The very high negative predictive value of mediastinal FDG-PET is able to reduce the need for invasive surgical staging substantially.
Replication of SV5 RNA and the effects of superinfection with poliovirus.

Abstract SV5-induced RNA synthesis has been studied in actinomycin-treated primary cultures of rhesus monkey kidney cells. Virus-induced RNA synthesis is first detected about 3 hours after infection, and during the period of maximum virus replication, RNA synthesis precedes virus production by 1 1 2 –2 hours. At its maximum rate, SV5-induced RNA synthesis is Superinfection with poliovirus of cells already producing SV5 does not inhibit, but rather slightly enhances, the ongoing replication of infective SV5. In contrast, puromycin causes a rapid inhibition of ongoing SV5 replication. The inoculation of poliovirus, 325 PFU/cell, in the presence of guanidine causes inhibition of cellular RNA and protein synthesis; however, such inoculation of cells previously infected with SV5 causes a stimulation of actinomycin-resistant, virus-induced RNA synthesis, and a slight enhancement of infective SV5 production. The results indicate that poliovirus does not shut off SV5 RNA-dependent RNA synthesis although it does shut off cellular DNA-dependent RNA synthesis. Furthermore, poliovirus does not inhibit SV5 protein synthesis under conditions in which it does inhibit cellular protein synthesis, thus providing an example of a functional distinction between SV5 messenger and cellular messenger RNA.
Modeling household fertility decisions with generalized Poisson regression.

This paper models household fertility decisions by using a generalized Poisson regression model. Since the fertility data used in the paper exhibit under-dispersion, the generalized Poisson regression model has statistical advantages over both standard Poisson and negative binomial regression models, and is suitable for analysis of count data that exhibit either over-dispersion or under-dispersion. The model is estimated by the method of maximum likelihood. Approximate tests for the dispersion and goodness-of-fit measures for comparing alternative models are discussed. Based on observations from the Panel Study of Income Dynamics of 1989 interviewing year, the empirical results support the fertility hypothesis of Becker and Lewis (1973).
Proximal interphalangeal joint injection through a volar approach: anatomic feasibility and cadaveric assessment of success.

Purpose The proximal interphalangeal (PIP) joint is a challenging joint to access reliably for corticosteroid injection. Literature has confirmed both a relatively high failure rate for injections performed with the traditional dorsal approach and an improved clinical response rate for confirmed intra-articular injections. We describe a technique for injecting the PIP joint through a volar approach, assess its reliability through cadaveric dissection, and determine its reproducibility by comparing success rates with the dorsal approach in a cadaver model. Methods We dissected the PIP joint of 10 cadaveric digits to document necessary anatomic landmarks for this technique. We then used 20 matched pairs of cadaver hands for the remainder of our study. Four PIP joints on each hand (thumb excluded) were injected with a solution of saline and radio-opaque dye using the dorsal approach. We injected each joint on the contralateral matched hand through the volar approach. We obtained standardized fluoroscopic images of each joint immediately after injection, which were reviewed by an independent observer who was blinded to the technique and who rated outcomes as success, failure, or mixed. Success rates were evaluated based on approach used, digit injected, and degree of pre-existing arthritis. Results We found reproducible anatomic landmarks that justified our injection technique. The rates of absolute failure were similar in the 2 cohorts. The volar approach demonstrated a higher percentage of successful injections with a smaller percentage of mixed results, although results did not reach statistical significance. There was no statistically significant difference in success rates based on digit injected or grade of arthritis in either cohort. Conclusions The volar approach to injecting the PIP joint demonstrated success similar to that of the traditional dorsal approach. Reproducible surface landmarks exist to guide practitioners using this technique. Further study is needed to determine the potential complications and clinical outcomes of the volar approach. Type of study/level of evidence Therapeutic IV.
Clinical application of a single compartment model to urea and creatinine kinetics in dialysis therapy.

Abstract A single compartment mathematical model has been shown to accurately describe changing serum concentrations of low molecular weight solutes (urea and creatinine) during dialysis. Clinical application of the model permits prediction of serum concentrations in response to changes in prescription of dialysis therapy. The programs presented here can be used to predict the effect of changes in treatment time and dialyzer clearance on serum concentrations. Sequential pre- and end-dialysis solute concentrations are displayed on a programmable pocket calculator. Dialyzer clearance during any individual dialysis can be calculated. These programs permit an evaluation of the efficacy of prescribed dialysis treatment schedules in advance of therapeutic trials.
A Resonant Microwave Patch Sensor for Detection of Layer Thickness or Permittivity Variations in Multilayered Dielectric Structures

A microwave nondestructive evaluation (NDE) sensor operating in the X-band (8.2 to 12.4 GHz) for detecting thickness or permittivity changes in one layer of multilayered dielectric structures is presented. In particular, detection of defects in the form of permittivity variations in the core layer of a three-layer structure, such as an aircraft radome, is targeted. Using an efficient analytical model for calculating the resonant frequency of a rectangular patch sensor covered with multilayered dielectric structures, the effects of varying the geometric and electrical parameters of the sensor on its performance are analyzed. According to this analysis and other empirical design equations, a resonant patch sensor was designed for good sensitivity to core permittivity changes, adequate penetration depth and spatial resolution. Experimental results showed that one particular sensor is capable of detecting a relative permittivity change as small as Δe = 0.046, can achieve spatial resolution 5 mm, and can inspect permittivity changes to depth 4.35 mm in the core of a three-layer dielectric structure. Measurements on a fiberglass-honeycomb-fiberglass structure containing injected water showed that 0.25 cc (one honeycomb cell) of water can be detected by this sensor.
146 Sm: A Chronometer for p-Process Nucleosynthesis

UNTIL now, nucleosynthetic chronologies have been proposed only for r-process nuclei1–5. Nucleosynthesis of the rare proton-rich isotopes is generally attributed to an as yet poorly understood p-process1. We propose the use of the p-process radioisotope, 146Sm(τ½ = 7×107 yr), as a possible nucleochronometer. The development of a p-process chronology would provide information about when the p-process occurred, which might provide a clue regarding the astrophysical site of the p-process.
Hate Speech or “Reasonable Racism?” The Other in Stormfront

We use the construct of the “other” to explore how hate operates rhetorically within the virtual conclave of Stormfront, credited as the first hate Web site. Through the Internet, white supremacists create a rhetorical vision that resonates with those who feel marginalized by contemporary political, social, and economic forces. However, as compared to previous studies of on-line white supremacist rhetoric, we show that Stormfront discourse appears less virulent and more palatable to the naive reader. We suggest that Stormfront provides a “cyber transition” between traditional hate speech and “reasonable racism,” a tempered discourse that emphasizes pseudo-rational discussions of race, and subsequently may cast a wider net in attracting audiences.
Summertime thermocline salinity maximum intrusions in the Mid-Atlantic Bight

Abstract Mooring data with high vertical resolution have been combined with hydrographic data to investigate the character of high salinity thermocline intrusions in the shelf water-slope water frontal zone in the southern Mid-Atlantic Bight. The coincidence of current, temperature and salinity data has allowed a detailed investigation of how the intrusion process is initiated. The data show that the time scale for both the onset and duration of the intrusions is very short. Most intrusions at a single location seem to last no more than a day, while the onshore flow associated with many, but not all, intrusions accelerates very quickly attaining amplitudes of 10–20 cm s −1 . As has been noted in earlier studies, there is a correlation between the intrusions and upwelling favorable winds, but the magnitude of the wind stress is not sufficient to account for the onshore transport of the intrusions. The combination of current measurements with density profiles has allowed the calculation of gradient Richardson numbers associated with the intrusions. These calculations show that during the strong onshore flow periods there is significant mixing at the boundaries of the intrusions. At other times when the high salinity water is being passively advected along the shelf, there appears to be little shear turbulence at the intrusion boundaries. Continuous data coverage during the summer suggests that the intrusion process is actually fairly infrequent, apparently requiring an offshore preconditioning in which high salinity waters of the correct density are located just offshore in addition to upwelling favorable winds.
Metabolism of adenosine analogues by Schistosoma mansoni and the effect of nucleoside transport inhibitors.

Schistosoma mansoni incorporated tubercidin, nebularine, 9-deazaadenosine, 5'-deoxy-5'-iodo-2-fluoroadenosine, 7,9-dideaza-7-thiaadenosine and toyocamycin but not sangivamycin, 3'-deoxy-sangivamycin, or 1-methylformycin into their nucleotide pool after a 4-hr incubation in vitro. In contrast to mammalian systems, addition of nucleoside transport inhibitors nitrobenzylthioinosine 5'-monophosphate (NBMPR-P), dilazep, or benzylacyclouridine had no significant effect on the pattern of incorporation of these adenosine analogues. Dipyridamole, on the other hand, reduced, but did not prevent, the incorporation of these analogues into the nucleoside 5'-triphosphate pool. These results suggest that the transport of purine nucleosides in schistosomes is different from that of their mammalian hosts. Therefore, coadministration of a specific nucleoside transport inhibitor with tubercidin, nebularine, 9-deazaadenosine, 5'-deoxy-5'-iodo-2-fluoroadenosine, toyocamycin, or 7,9-dideaza-7-thiaadenosine may result in high selective toxicity against schistosomes, as was the case with the combination of tubercidin plus NBMPR-P [el Kouni et al., Proc. natn. Acad. Sci. U.S.A. 80, 6667 (1983); el Kouni et al., Biochem. Pharmac. 34, 3921 (1985)], by protecting the host but not the parasite from the toxicity of these analogues.
Gene Therapy: A Potential Approach for Cancer Pain

Chronic pain is experienced by as many as 90% of cancer patients at some point during the disease. This pain can be directly cancer related or arise from a sensory neuropathy related to chemotherapy. Major pharmacological agents used to treat cancer pain often lack anatomical specificity and can have off-target effects that create new sources of suffering. These concerns establish a need for improved cancer pain management. Gene therapy is emerging as an exciting prospect. This paper discusses the potential for viral vector-based treatment of cancer pain. It describes studies involving vector delivery of transgenes to laboratory pain models to modulate the nociceptive cascade. It also discusses clinical investigations aimed at regulating pain in cancer patients. Considering the prevalence of pain among cancer patients and the growing potential of gene therapy, these studies could set the stage for a new class of medicines that selectively disrupt nociceptive signaling with limited off-target effects.
Analytical studies of a backscatter x-ray imaging landmine detection system

The Compton Backscatter Imaging (CBI) technique has been applied successfully to detect buried plastic anti-tank landmines. The images acquired by a CBI system are often cluttered by surface features. Additionally, some buried objects give the same response as the plastic landmines. The landmine detection can be successful only when the detection system is capable of distinguishing between surface features and the mine-like objects. This can be accomplished by designing detectors that differentiate between the surface features and the buried objects. An understanding of the physical phenomena underlining the CB image formation helps us to design these detectors. To study the physics of the Compton backscattering, the photon transport in a CBI system is simulated using Monte-Carlo calculations with the generalized particle transport program MCNP. The photon tracks are graphically displayed using a visualization program SABRINA. On the basis of the results from these Monte-Carlo analyses, a four-detector system has been designed. This detector design utilizes the unique nature of various collision components of the scattered photons to generate separate images of buried objects and surface features. The success of this detector design is demonstrated through a series of analytically generated images. The results of the experimental measurements that validate these analytical predictions are brought out in a separate paper to be presented in this conference.
Optimal multilayer filter design using real coded genetic algorithms

A novel approach for designing optimal multilayer filters based on a real-coded genetic algorithm is presented. Given the total number of layers in the filter, as well as the electrical properties of the materials constituting each layer, the algorithm iteratively constructs multilayers whose frequency response closely matches a desired frequency response. In contrast to existing iterative techniques, this method does not require a preliminary design using classical techniques. Also, the design procedure is independent of the nature of the multilayer as well as the characteristics of the incident and substrate media. The algorithm is applied to the design of various lowpass and high-pass optical filters, operating between practical terminal conditions. The performance of the resulting designs matches or improves on that for filters that were synthesised using semiclassical techniques.
Projecting From Advance Data Using Propensity Modeling: An Application to Income and Tax Statistics

This article proposes and evaluates two new methods of reweighting preliminary data to obtain estimates more closely approximating those derived from the final data set. In our motivating example, the preliminary data are an early sample of tax returns, and the final data set is the sample after all tax returns have been processed. The new methods estimate a predicted propensity for late filing for each return in the advance sample and then poststratify based on these propensity scores. Using advance and complete sample data for 1982, we demonstrate that the new methods produce advance estimates generally much closer to the final estimates than those derived from the current advance estimation techniques. The results demonstrate the value of propensity modeling, a general-purpose methodology that can be applied to a wide range of problems, including adjustment for unit nonresponse and frame undercoverage as well as statistical matching.
Variable effects of phosphorylation of pit-1 dictated by the DNA response elements

Pit-1, a tissue-specific POU domain transcription factor, is required for the activation of the prolactin, growth hormone, and Pit-1 promoters that confer regulation by epidermal growth factor, adenosine 3',5'-monophosphate (cAMP), and phorbol esters. Pit-1 is phosphorylated in pituitary cells at two distinct sites in response to phorbol esters and cAMP. Phosphorylation of Pit-1 modifies its conformation on DNA recognition elements and results in increased binding at certain sites and decreased binding at other sites, dependent on DNA sequences adjacent to the core Pit-1 binding motif. One residue (Thr220), located in the POU homeodomain within a sequence conserved throughout the POU-domain family, confers these responses.
Transforming growth factors in human breast cancer

Abstract Transforming growth factors α and β(TGFα and TGFβ) are two growth factors which are frequently associated with a number of human breast cancer cell lines and with primary human breast carcinomas. Expression of TGFα protein and specific TGPα mRNA transcripts (4.8 and 1.6kb) can be induced by estiogens in estrogen-responsive breast cancer cells, suggesting that the mitogenic effects of estrogen may in pan be mediated through this potential autocrine growth factor. In contrast, anti-estrogens such as tamoxifen can increase the secreted levels of TGFβ, which is a potent growth-inhibitor for some human breast cancer cell lines. Anti-estrogens generally decrease TGFα production. TGFα mRNA expression has been detected in approximately 40–70 % of primary human breast tumors, while expression of a 2.6 kb TGFβ mRNA transcript can be detected in 70–80 % of breast tumors. Interference with (e.g. TGFα) or augmentation of (e.g. TGFβ) the effects of these two growth factors may have some potential clinical applications in the treatment of breast cancer. transforming growth factors/breast cancer
Rat Caries Assay of Reference Foods and Sugar-containing Snacks

Using standard reference snack foods, we tested a method, using rats fed in a programmed feeding machine, to evaluate the caries-promoting properties of foods. Results, which were expressed in relation to a control food, indicate that the method distinguished differences in caries potential among a number of different snack foods. Buccal and sulcal caries scores of rats fed snacks foods varied in their responses. A gel diet used to provide essential nutrients for the rat growth in this approach contributed minimally to the caries response which was related principally to the food being tested.
Real-time Analysis of G Protein-coupled Receptor Reconstitution in a Solubilized System

Receptor based signaling mechanisms are the primary source of cellular regulation. The superfamily of G protein-coupled receptors is the largest and most ubiquitous of the receptor mediated processes. We describe here the analysis in real-time of the assembly and disassembly of soluble G protein-coupled receptor-G protein complexes. A fluorometric method was utilized to determine the dissociation of a fluorescent ligand from the receptor solubilized in detergent. The ligand dissociation rate differs between a receptor coupled to a G protein and the receptor alone. By observing the sensitivity of the dissociation of a fluorescent ligand to the presence of guanine nucleotide, we have shown a time- and concentration-dependent reconstitution of the N-formyl peptide receptor with endogenous G proteins. Furthermore, after the clearing of endogenous G proteins, purified Galpha subunits premixed with bovine brain Gbetagamma subunits were also able to reconstitute with the solubilized receptors. The solubilized N-formyl peptide receptor and Galpha(i3) protein interacted with an affinity of approximately 10(-6) m with other alpha subunits exhibiting lower affinities (Galpha(i3) > Galpha(i2) > Galpha(i1) Galpha(o)). The N-formyl peptide receptor-G protein interactions were inhibited by peptides corresponding to the Galpha(i) C-terminal regions, by Galpha(i) mAbs, and by a truncated form of arrestin-3. This system should prove useful for the analysis of the specificity of receptor-G protein interactions, as well as for the elucidation and characterization of receptor molecular assemblies and signal transduction complexes.
What sensory signals are about

In 'Of sensory systems and the "aboutness" of mental states', Kathleen Akins (1996) argues against what she calls 'the traditional view' about sensory systems, according to which they are detectors of features in the environment outside the organism. As an antidote, she considers the case of thermoreception, a system whose sensors send signals about how things stand with themselves and their immediate dermal surround (a 'narcissistic' sensory system); and she closes by suggesting that the signals from many sensory systems may not in any familiar sense be about anything at all. Her presentation of the issues, however, overlooks resources available to 'the traditional view' or so I shall argue. Akins's own thumbnail sketch of what is wrong with the traditional view is that it asks, concerning a given sensory system, 'what is it detecting?', when we should instead be asking 'what is it doing?' (352). Her point is that on the traditional view the function of a sensory system what it's 'for' is to detect or indicate (values of) features of the outside environment. But at least on one version of the traditional view namely Ruth Millikan's this would never be the sole or main proper function of a sensory system. (Akins does not list Millikan as a traditionalist, but Millikan fits squarely Akins's description of them, since she believes in a naturalistic theory of aboutness and thinks it should begin with the senses.) For Millikan (1989, 1993), the proper function of a sensory system is in the first instance enabling behavioural systems in the simplest case, motor routines to perform their proper function. This they do, roughly, by switching on and steering the behavioural routines. Where features of the outside environment come in is as Normal (= assumed-by-the-design) conditions for the successful performance of the sensory system's proper function. That is, the only strategy for switching on and steering that is simple enough for evolution to have hit upon it, and reliable enough for evolution to have liked it, is a strategy which gears the steering to (values of) features of the outside environment. But as soon as one starts fleshing out the details of this story, one notices that they are probably quite different in the case of thermoreception from how they are with 'distance' senses such as vision and olfaction a point which Akins overlooks. It is likely that a proper function (maybe the proper function) of the thermoreceptive system is to steer motor routines so as to ward off freezing and cooking of the skin. The only strategy for steering here which has the requisite combination of simplicity and
The REG1 anticoagulation system: a novel actively controlled factor IX inhibitor using RNA aptamer technology for treatment of acute coronary syndrome

Antithrombotic agents including anticoagulants and antiplatelets are the cornerstone of treatment of acute coronary syndromes. Currently available anticoagulants have several important limitations including unpredictable pharmacodynamics, immunogenicity, and difficulty in reversibility. A potent anticoagulant that has predictable efficacy, is easily reversible should the clinical need arise, and reduces ischemic events without an increase in bleeding risk would overcome many of the current limitations. Inhibition of factor IX in the coagulation cascade has shown promise as a target for development of a novel anticoagulant with a favorable bleeding risk. Aptamers are small oligonucleotides that can be developed to inhibit specific protein targets with high affinity and used as active drugs. Because aptamers are made of oligonucleotide sequences, they provide the code for their own complement (reversal agent) that can be developed and used to inhibit their function. The REG1 anticoagulation system is a nove...
A digestion bomb for wet ashing biological materials

The design and construction of a wet digestion chamber resistant to acids and bases for hard and soft tissues is described. Loss of volatile elements is prevented. Reproducible complete recoveries for a variety of inorganic metal ions are routinely achieved.
The Physical Organization as Equivocal Message

This study expands our understanding of the importance of physical organizational space and the relationship between physical and social structure by emphasizing and demonstrating how social structure is physically contextualized. I examined the impact of a building designed specifically to enhance communication and creativity among workers and discovered that users of the building experienced the facility very differently than the designers intended. Specifically, employees struggled to reconcile their experiences with the new facility across five problematic themes: transition, openness, finances/layoffs, management, and the building itself, with the building serving a core, unifying function. The results are discussed in terms of how organizational physical space affords opportunities for material space use that may be unforeseen by designers. Workers’ values and the impact of multiple stressors played key roles in the negative reactions to the new facility. J. J. Gibson's theory of affordances is used...
Some in vitro assay conditions that affect detection and quantitation of phenobarbital-induced increases in hepatic microsomal drug-metabolizing enzyme activity

Abstract Different laboratories use a variety of “standard” incubation conditions to assay in vitro for hepatic microsomal drug-metabolizing enzyme activity. Incubation volumes of 3–5 ml often contain 9000 g supernatant fractions or microsomes from 250 mg to 1.0 g of liver. Microsomal protein concentrations in such incubation mixtures will often exceed 2 mg/ml. Many workers do not specify rate of shaking or gas flow rate used in such incubations, and open air rather than flowing oxygen is often the gas phase. Under certain of these “standard” conditions we have been unable to demonstrate increased drug metabolism by hepatic fractions from phenobarbital-treated as compared with control rats. Incubation conditions contributing to this difficulty in demonstrating enzyme induction by phenobarbital were: (1) too much protein; (2) too slow shaking rate; (3) too little agitation of incubation mixtures; and (4) use of open air rather than flowing oxygen as gas phase. Incubation conditions which provided good evidence of the effects of phenobarbital as an inducer of the hepatic microsomal enzymes studied included: (1) microsomal protein concentrations in the incubation mixture of less than 2 mg/ml; (2) shaking rate of 100 oscillations per minute; (3) addition of a glass marble to the incubation mixture; and (4) gassing with oxygen rather than leaving open to the air.
Venography during endoscopic injection sclerotherapy of esophageal varices.

Utilizing an equal mixture of 5% sodium morrhuate and 60% renografin, we studied four patients during a total of nine sessions of injection sclerotherapy of esophageal varices to determine radiographically the fate of injected sclerosant. Despite attempted intravariceal injections, 44% resulted in local and presumably paravariceal accumulation of contrast material within the esophageal wall. During 42% of injections, contrast material was rapidly cleared in a cephalad direction and proximal balloon comression of the esophagus did not prevent cephalad flow of sclerosant. In 14% the injected material was rapidly cleared in a caudal direction toward the gastric veins. This technique may be useful in future evaluations of the efficacy of various methods of injection sclerotherapy of esophageal varices.
Characterizing Landing Pages in Sponsored Search

Using a total of 60,419 ad links collected from three search engines (i.e., Bing, Google, and Yahoo), we characterize the ``mobile-friendliness'' of landing pages in sponsored search. In particular, we analyze the common and different characteristics between landing pages made for desktop vs. mobile device users, measure/validate the quantitative scores for their mobile-friendliness, and classify the results with respect to types of queries and landing pages. Based on our findings, we articulate that: (1) current landing pages (regardless of search engines or platforms) are \emph{not} mobile-friendly enough, and (2) better data-driven methods (as opposed to current static methods) to help advertisers build mobile-friendly landing pages are needed.
Antioxidant and pro-oxidant activity of (-)-epigallocatechin-3-gallate in food emulsions: Influence of pH and phenolic concentration

Polyphenols have been observed to exert both antioxidant and pro-oxidant activity in lipid foods, and factors that influence that net effect include both polyphenol concentration and matrix pH. In this study, the effects of concentration (1-500 μM) of a model polyphenol, (-)-epigallocatechin-3-gallate (EGCG), and matrix pH (2-7) on the net anti-/pro-oxidant activity of EGCG in flaxseed oil-in-water (o/w) emulsions were systematically evaluated. After 24h, EGCG (5-100 μM) was observed to exhibit pro-oxidant activity in low pH (pH 2-4) emulsions, as determined by conjugated dienes (CDs) and thiobarbituric acid reactive substances (TBARSs) production. At the higher pH values studied (pH 5-7), lower CD and TBARS concentrations were detected in samples with 25-500 μM EGCG at 24h. Overall, EGCG concentration and pH both played significant roles in determining net antioxidant or pro-oxidant effects, with the largest antioxidant and pro-oxidant effects observed at the higher EGCG concentrations (100-500 μM) tested.
Synchronization of estrus in yearling beef heifers with melengestrol acetate and prostaglandin F2α

This study was designed to test the efficacy of melengestrol acetate (MGA) in combination with prostaglandin F(2alpha) (PGF(2alpha)) in synchronizing estrus in cyclic and noncyclic heifers. One hundred thirty-one cyclic and prepubertal crossbred heifers were randomly assigned to three treatment groups: Controls (n = 43); MGA (0.5 mg/d for 7 d) and PGF(2alpha) (25 mg i.m. on Day 7; n = 44); and PGF(2alpha) (25 mg i.m. on Day 7; n = 44). Observations for estrus were made at 6-n intervals throughout the 7-d treatment period followed by a 34-d artificial insemination breeding season. A greater percentage (P 0.05) between synchronization rates of the MGA-PGF(2alpha) heifers and PGF(2alpha) heifers 7 d after PGF(2alpha) administration. The percentage of control animals in estrus during the first 25 d of the breeding season did non differ from the synchronized rates of MGA-PGF(2alpha) and PGF(2alpha) heifers (P > 0.05). Conception rates (heifers pregnant/heifers inseminated) did not differ (P > 0.05) for cyclic or prepubertal heifers among Control, MGA-PGF(2alpha) or PGF(2alpha) heifers. Though conception rates did not differ, there was a trend toward lowered conception rates in MGA-PGF(2alpha) heifers.
Development of the spatio-chromatic visual evoked potential (VEP): a longitudinal study

Most prior visual evoked potential (VEP) research on the development of color vision has employed pattern-reversing stimuli that are not optimal for producing chromatic responses. We measured infant VEPs using low spatial frequency, onset‐offset stimuli, modulated along the three axes of a cone-based color space (Derrington et al. [J Physiol 1984;357, 241‐265.]). Three color-normal infants were tested in a longitudinal design over the first postnatal year. One red:green color-deficient infant was also tested at 197 days. We found that VEP responses to S-axis (tritan) stimuli have their initial onset later than responses to red:green (L‐M) or achromatic stimuli, and that developmental changes in VEP waveforms are more complex and longer lasting for chromatic than for achromatic stimuli. Possible mechanisms underlying these changes are discussed. © 1998 Elsevier Science Ltd. All rights reserved.
Designing an AI emotion-based adaptive fuzzy system for evaluation of the computer music

This paper focuses on a design of a template for an AI emotion-based adaptive fuzzy system that analyzes music and simulates the audience's emotional reaction. This system may possibly aid computer music composers in creating music that is more appealing to the wider audiences. Conceptual design of the proposed system is based on the most recent findings in understanding of how the human brain processes musical patterns. This could be summarized in the following statement: any deviation from the musical pattern predictability, in the listener's mind, tend to weaken subsequent pattern anticipation and thereby undercut the impact of further musical deviations. Every single mismatch in musical pattern anticipation is countered by adjustments to the next expectation. When too many deviations fall together, the listener loses track of the underlying musical stability and ceases to anticipate the coming patterns forcefully. With too many deviations, music becomes increasingly incoherent. With too little, music becomes cold and mechanical.
Grid staining--a useful device

A simple and disposable holder for electron microscope grids can be constructed from discs of silicon rubber. The discs (10 mm thick X 25 mm diameter) are scored 0.4 mm deep with a razor. Flexing the discs opens the scores for insertion of grids. Staining wells can be made from polyethylene snap-in vial tops by cutting away the nipple-like portion. After impaling the holders on the tips of a pair of forceps the grids can be washed by immersion. This holder is rigid, inert and inexpensive. It is of particular advantage for handling single-slotted grids.
Temporal and spatial variability in thalweg profiles of a gravel‐bed river

This study used successive longitudinal thalweg profiles in gravel-bed rivers to monitor changes in bed topography followingfloodsandassociatedlargesedimentinputs.Variationsinchannelbedelevations,distributionsofresidualwater depths,percentage of channellengthoccupied byriffles,andaspatial autocorrelationcoefficient (Moran’sI) wereused to quantify changes in morphological diversity and spatial structure in Redwood Creek basin, northwestern California. Bed topographyinRedwoodCreekanditsmajortributariesconsistsprimarilyofaseriesofpoolsandriffles.Thesize,frequency and spatial distribution of the pools and riffles have changed significantly during the past 20 years. Following large floods and highsediment input inRedwood Creek and its tributaries in 1975, variation in channelbed elevations was low and the percentageofthechannellengthoccupiedbyriffleswashigh.Overthenext20years,variationinbedelevationsincreased while the length of channel occupied by riffles decreased. An index [(standard deviation of residual water depth/bankfull depth) 100]wasdevelopedtocomparevariationsinbedelevationoverarangeofstreamsizes,withahigherindexbeing indicativeofgreatermorphologicaldiversity.Spatialautocorrelationinthebedelevationdatawasapparentatbothfineand coarsescalesinmanyofthethalwegprofilesandtheobservedspatialpatternofbedelevationswasfoundtoberelatedtothe dominant channel material and the time since disturbance. River reaches in which forced pools dominated, and in which large woody debris and bed particles could not be easily mobilized, exhibited a random distribution of bed elevations. In contrast, in reaches where alternate bars dominated, and both wood and gravel were readily transported, regularly spaced bed topography developed at a spacing that increased with time since disturbance. This pattern of regularly spaced bed featureswasreversedfollowinga12-yearfloodwhenbedelevationsbecamemorerandomlyarranged.Copyright#1999 John Wiley & Sons, Ltd.
Assessing hyperkeratotic lesions in the older patient

Hyperkeratotic lesions in the older patient create pain and deformity, limit ambulation, and may predispose the patient to ulceration. These lesions have multiple etiologies, particularly in the older patient, including the normal physiological changes of aging, disease, deformity, changes in balance, shoe last incompatibilities, and inappropriate footwear. This article outlines the signs, symptoms, and management of hyperkeratonic lesions.
A Robust Approach to IMRT Optimization

Managing uncertainty is a major challenge in radiation therapy treatment planning, including uncertainty induced by intrafraction motion, which is particularly important for tumours in the thorax and abdomen. Common methods to account for motion are to introduce a margin or to convolve the static dose distribution with a motion probability density function. Unlike previous work in this area, our development does not assume that the patient breathes according to a fixed distribution, nor is the patient required to breathe the same way throughout the treatment. Despite this generality, we create a robust optimization framework starting from the convolution method that is robust to fluctuations in breathing motion, yet spares healthy tissue better than a margin solution. We describe how to generate the data for our model using breathing motion data and we test our model on a computer phantom using data from real patients. In our numerical results, the robust solution delivers approximately 38% less dose to the healthy tissue than the margin solution, while providing the same level of protection against breathing uncertainty.
An Exploration of Hybrid Spaces for Place-Based Geomorphology with Latino Bilingual Children.

ABSTRACT Latino bilingual children hold rich understandings, which are underexplored and underutilized in the geoscience classroom. Oftentimes, young Latinos possess unique cultural land experiences shaping their place identities. We consider science as language and culture, and propose place-based geoscience hybrid space explorations that are culturally and linguistically relevant. We explore the different elements that help bilingual children learn geoscience using pre- and postsurvey of their understanding of the processes of erosion, transportation, and deposition; children's marks, drawing, and writing on a photograph; and graphic organizers with children's notes. Several different instructional elements for working with Latino bilinguals, organized around five tenets of culture, arise from our analysis: (1) Utilizing multiple linguistic resources, (2) making explicit connections to alternative interpretations of words, (3) using culturally relevant examples, (4) using alternative and creative ways o...
Erich Hückel – Pionier der Organischen Quantenchemie: Leben, Wirken und späte Anerkennung

Zwischen 1930 und 1937 kamen von Erich Huckel, einem theoretisch arbeitenden Physiker, mit den quantenmechanischen Beschreibungen ungesattigter und konjugierter Molekule wesentliche Beitrage zur Organischen Chemie. Hier folgt einem kurzen Uberblick uber seine wissenschaftliche Laufbahn aus der Sicht eines Organikers eine vereinfachte Darstellung der stark approximativen theoretischen Methoden, die er verwendete. Fur cyclische Molekule der Klasse CnHn ist die Aussage, das im Fall von (4N + 2) π-Elektronen (N = 0,1,2,…) abgeschlossene Schalen vorliegen, von besonderer Bedeutung. Die Analyse von Schlusselanwendungen der Ideen Huckels zeigt, wie sie schlieslich die Erforschung neuer Gebiete in der organischen Synthese und bei organischen Reaktionsmechanismen anregten. Ein weiterer bedeutsamer (aber bis vor kurzem kaum beachteter) Beitrag von Huckel war die Erkenntnis, das die Konnektivitat der Atome ein entscheidender Faktor fur die Spinmultiplizitat in Nicht-Kekule-Molekulen ist. Sie liefert, wie jungere theoretische und experimentelle Befunde bestatigen, im Prinzip eine Basis fur die Voraussage von Verstosen gegen die Hundsche Regel. Daruber hinaus werden die Wechselwirkung von Experimenten mit den unterschiedlichen Auspragungen der Quantentheorie und die Auswirkung dieser Wechselwirkung auf die Entwicklung der Chemie kurz betrachtet. Schlieslich werden Mutmasungen angestellt, warum das Werk Huckels jahrzehntelang einen so geringen Einflus auf die Organische Chemie ausubte, bis man endlich anfing, seine Bedeutung zu erkennen.