cssi/SciSciGPT-SciSciNet huggingface dataset:
Excitation Energy Transfer between the B850 and B875 Antenna Complexes of Rhodobacter sphaeroides

Energy transfer between the B850 (LH2) and B875 (LH1) antenna complexes of a mutant strain of Rhodobacter sphaeroides lacking reaction centers is investigated by femtosecond pump-probe spectroscopy at room temperature. Measurements are made at wavelengths between 810 and 910 nm at times extending to 200 ps after selective excitation of either B850 or B875. Assignments of the spectroscopic signals to the two types of antenna complex are made on the basis of measurements in strains that lack either LH1 or LH2 in addition to reaction centers. Energy transfer from excited B850 to B875 proceeds with two time constants, 4.6 ± 0.3 and 26.3 ± 1.0 ps, but a significant fraction of the excitations remain in B850 for considerably longer times. The fast step is interpreted as hopping of energy to LH1 from an associated LH2 complex; the slower steps are interpreted as migration of excitations in the LH2 pool preceding transfer to LH1. Transfer of excitations from B875 to B850 could not be detected, possibly suggesting...
Improving positioning in LTE through collaboration

This paper represents a preliminary study of cooperative positioning in Long Term Evolution (LTE) systems. Many applications, such as location-based services and Enhanced 911 (E911), require that the locations of users in a cellular system are available. The global navigation satellite system (GNSS) is the most accessible positioning systems which are widely used in cellphones. However, poor operation in indoor and dense environments leads us to use cellular localization as a backup solution. In cellular localization, the locations of users are determined via measurements obtained within the network without aid of any external sources (e.g., GNSS). Observed time difference of arrival (OTDOA) is a positioning technique introduced in Release 9 of the 3GPP LTE specification. In OTDOA technique, the User Equipment (UE) measures the time difference of signals between several eNodeBs (base stations in LTE) and uses a trilateration algorithm to find its location. In the current 3GPP LTE specification, the UE can only collect measurements from eNodeBs. Therefore, in many situations, the UE is not able to communicate to a sufficient number of eNodeBs and cannot find its location without ambiguity. In this paper, we propose a cooperative localization technique for LTE systems in which the UE communicates not only with eNodeBs but also with other UEs. It will be shown that cooperative localization can significantly improve the localizability in the network, meaning that more UEs can be localized. Cooperative localization also enhances the accuracy which is highly beneficial for some applications, especially E911. A series of computer simulations are conducted to show the benefits of cooperative localization where the 3GPP simulation parameters are assumed.
Intracellular and extracellular osmoregulation of temperature acclimated goldfish: Carassius auratus L.

Abstract 1. 1. Goldfish were acclimated to temperatures ranging from 21.5 to 1°C. 2. 2. Acclimation to near freezing temperatures caused a reduction in plasma osmolality due to decreased organic solutes as well as reduced plasma inorganic ions. 3. 3. Plasma Na+ concn decreased in lower temperatures; plasma Cl− did not. 4. 4. RBC response to decreased plasma osmolality included phases: osmotic swelling followed by cellular shrinkage. 5. 5. Cellular shrinkage resulted from efflux of KC1 and water. 6. 6. The over-all response is an example of “isosmotic intracellular regulation” achieved by adjusting osmotically active particles.
Review of: Forensic DNA Typing, 2nd edition

This second edition of Dr. Butler's Forensic DNA Typing, the first edition of which appeared in 2001, is more than twice the size of the original—reflecting the astonishing rate at which new information is accumulating in this field. If developments in forensic DNA typing continue at this pace, a hypothetical third edition, appearing around 2009, will be more than 900 pages long.
Neurenteric cysts of the spine

Neurenteric cysts account for 0.7-1.3% of spinal axis tumors. These rare lesions result from the inappropriate partitioning of the embryonic notochordal plate and presumptive endoderm during the third week of human development. Heterotopic rests of epithelium reminiscent of gastrointestinal and respiratory tissue lead to eventual formation of compressive cystic lesions of the pediatric and adult spine. Histopathological analysis of neurenteric tissue reveals a highly characteristic structure of columnar or cuboidal epithelium with or without cilia and mucus globules. Patients with symptomatic neurenteric cysts typically present in the second and third decades of life with size-dependent myelopathic and/or radicular signs. Magnetic resonance imaging and computed tomography are essential diagnostic tools for the delineation of cyst form and overlying osseous architecture. A variety of approaches have been employed in the treatment of neurenteric cysts each with a goal of total surgical resection. Although long-term outcome analyses are limited, data available indicate that surgical intervention in the case of neurenteric cysts results in a high frequency of resolution of neurological deficit with minimal morbidity. However, recurrence rates as high as 37% have been reported with incomplete resection secondary to factors such as cyst adhesion to surrounding structure and unclear dissection planes. Here we present a systematic review of English language literature from January 1966 to December 2009 utilizing MEDLINE with the following search terminology: neurenteric cyst, enterogenous cyst, spinal cord tumor, spinal dysraphism, intraspinal cyst, intramedullary cyst, and intradural cyst. In addition, the references of publications returned from the MEDLINE search criteria were surveyed in order to examine other pertinent reports.
Finite element‐based model order reduction of electromagnetic devices

In this paper an efficient algorithm is presented for the development of compact and passive macro-models of electromagnetic devices through the systematic reduction of the order of discrete models for these devices obtained through the use of finite elements. The proposed methodology is founded on a new finite element formulation that casts Maxwell's curl equations in a state-space form. Such state-space representations are very compatible with a class of robust model order reduction techniques based on Krylov subspaces. However, the advantage of this compatibility appears to be hindered by the fact that the state matrix of the discretized Maxwellian system is of dimension almost twice that obtained from the finite element approximation of the electromagnetic vector wave equation. It is shown in this paper that the apparent penalty in both memory and computation efficiency can be avoided by a proper selection of the finite element expansion functions used for the discretization of the electromagnetic fields. More specifically, it is shown that the proper selection of expansion functions renders the state-space form of the Maxwellian system equivalent to the discrete problem obtained from the approximation of the vector wave equation using tangentially continuous vector finite elements. This equivalence is then used to effect Krylov-based model order reduction directly from the finite element approximation of the vector wave equation. In particular, a passive model order reduction algorithm is used for this purpose. The proposed reduced order macro-modelling algorithm is demonstrated through its application to a variety of microwave passive components. Copyright © 2002 John Wiley & Sons, Ltd.
The intravenous use of high molecular ferric carbohydrate compound in the treatment of hypochromic anemia.

Twenty patients with hypochromic anemia were given a total of 211 intravenous injections of high molecular ferric carbohydrate compound. The hematologic response and toxic reactions are discussed. High molecular ferric carbohydrate compound can be given in large enough doses to be practical in the treatment of iron deficiency anemias. The hematologic response, as judged by the rate at which hemoglobin regenerates and the reticulocyte count increases, is good. The initial dose would be 25 to 50 mg. of elemental iron, and subsequent daily doses should not be more than 200 mg. Cases for the intravenous use of iron should be carefully selected because of the possible toxic reactions and the possible long-term damage to the tissues if excess amounts of irons are administered. The indications for the intravenous use of iron in iron deficiency anemias have been suggested. The dosage should be calculated so as to supply only enough iron to replace the irons deficiency and to allow regeneration of hemoglobin.
Unresectable pheochromocytoma: Response to α-methyl-dihydroxy-l-phenylalanine

Abstract α-Methyl-DOPA, an aromatic l -amine decarboxylase inhibitor, was administered to a patient with an actively secreting, unresectable pheochromocytoma. Sweating, flushes, palpitations and headache diminished. The blood pressure was decreased in the erect position. Urinary excretion of VMA was not significantly depressed. Marked sensitivity to oral phentolamine was noted. These effects may be due to depletion of tissue norepinephrine by AMD or its decarboxylation product.
Predicting aneurysm enlargement in patients with persistent type II endoleaks.

Abstract Objective The clinical significance of type II endoleaks is not well understood. Some evidence, however, indicates that some type II endoleaks might result in aneurysm enlargement and rupture. To identify factors that might contribute to aneurysm expansion, we analyzed the influence of several variables on aneurysm growth in patients with persistent type II endoleaks after endovascular aortic aneurysm repair (EVAR). Methods In a series of 348 EVARs performed during a 10-year period, 32 patients (9.2%) developed type II endoleaks that persisted for more than 6 months. Variables analyzed included those defined by the reporting standards for EVAR (SVS/AAVS) as well as other endoleak characteristics. Univariate, receiver operating characteristic curve, and Cox regression analyses were used to determine the association between variables and aneurysm enlargement. Results The median follow-up period was 26.5 months (range, 6-88 months). Thirteen patients (41%) had aneurysm enlargement by 5 mm or more (median increase in diameter, 10 mm), whereas 19 (59%) had stable or shrinking aneurysm diameter. Univariate and Cox regression analyses identified the maximum diameter of the endoleak cavity, ie, the size of the nidus as defined on contrast computed tomography scan, as a significant predictor for aneurysm enlargement (relative risk, 1.12; 95% confidence interval, 1.04-1.19; P = .001). The median size of the nidus was 23 mm (range, 13-40 mm) in patients with aneurysm enlargement and 8 mm (range, 5-25 mm) in those without expansion (Mann-Whitney U test, P P = .02). Other risk factors including gender, smoking history, hypertension, need of anticoagulation, aneurysm diameter, type of endograft used, and number or type of collateral vessels were not significant predictors of aneurysm enlargement. Conclusions In patients with persistent type II endoleaks after EVAR, the maximum diameter of the endoleak cavity or nidus is an important predictor of aneurysm growth and might indicate the need for more aggressive surveillance as well as earlier treatment.
Surface-crack shape change in bending fatigue using an inexpensive resonant fatiguing apparatus

An inexpensive device for producing surface cracks of controlled size and shape is described along with results of its use which show how the shape of the surface crack changes as it grows in bending fatigue from a variety of crack starter shapes. The growth pattern for any crack is uniquely defined by the crack starter configuration and appears to be independent of alloy. Shape changes are substantial and all growth curves tend toward a common growth curve. Circular cracks tend to become elliptical with an associated increase in stress intensity factor. This increase accelerates the crack growth rate and proximity to the critical flaw size. Through-cracks produced by the extension of a surface crack in a bending stress field will have length ten times the section thickness. The results demonstrate the necessity of taking into account changing crack shape in the calculation of structural life when bending is a significant component of the stress field.
Dynamics of erythrocyte motion in filtration tests and in vivo flow

The characteristics of low haematocrit erythrocyte suspension flow through the 5 μm pores of a nuclepore filter, under low pressure drops, are compared to those of red cell flow through the human spleen.(a) For suspension filtration when the haematocrit is less than 1.5% and the pressure drops are less than 1 cmH2O, the characteristic RBC transit time through a 5–μm pore filter is about 10 ms, with an overall average velocity of about 1 mm/s, with the fraction of the unplugged filter pores occupied by RBC about 3.5 times the haematocrit of the filtrate.(b) In the human spleen, the mean residence time in the red pulp is about 66 s or longer, with an average velocity of 0.25 μm/s or less. During transit through the sinus wall slits (about 1 μM by 6 μm rectangular openings, about 2 μm long, residence time is estimated to be 10 s or longer.Considering the differences in these flow situations (and assuming the human spleen provides the critical in vivo RBC deformability test), it would seem necessary to demons...
A little knowledge goes a long way: knowledge-based derivations and correctness proofs for a family of protocols

A high-level, knowledge-based approach for deriving a family of protocols for the sequence transmission problem is presented. The protocols of Aho et al. [2, 3], the Alternating Bit protocol [5], and Stenning's protocol [44] are all instances of one knowledge-based protocol that is derived. The derivation in this paper leads to transparent and uniform correctness proofs for all these protocols.
Melatonin: A clinical perspective

Over the last several decades the pineal gland has emerged as an active neuroendocrine transducer of important environmental information. However, the current understanding of the function of its major hormone, melatonin, in humans remains ill defined and based exclusively on correlative observations. In a similar manner, the multitude of phenomenological descriptions of the effects of exogenous melatonin is contrasted by the limited understanding of the underlying mechanisms and the lack of firmly established clinical applications for the hormone. Future randomized, double-blind, placebo-controlled clinical studies will be necessary to determine the precise indications, treatment regimens, and safety of melatonin in clinical practice. The recent rapid progress in the area of melatonin research should lead to a better understanding of its role in human health and disease.
Health, safety and loss control topics in the senior design courses

The undergraduate chemical engineering curriculum at most U.S. colleges and universities is already very tightly structured, largely to meet accreditation criteria while still providing broad-based education for the future. Health, safety and loss control issues were added to the program at the University of New Mexico through the use of weekly mini-lectures in the senior design courses. Mini-lectures, each ten to fifteen minutes, cover such topics as fires, explosions, the Bhopal incident, the Dow-Mond index, fault-tree analysis, HAZOP analysis, etc.
Observations on hospital room contamination testing

Abstract Background The environment has increasingly been shown to be involved in transmission of healthcare-associated infections, but data on environmental cleanliness assessment are relatively sparse. Method Environmental samples were collected from 18 high touch surfaces in 10 different acute care hospital rooms before cleaning to provide data on the rank order of cleanliness by site using both adenosine triphosphate (ATP) detection and quantitative microbiology. In addition, pre-and post-cleaning pooled samples of surfaces from 10 rooms were analysed by culture and sensitivity analysis to detect organisms of concern in the hospital. Results Four surfaces were ranked in the top six for contamination by both ATP and culture detection (bedrail control panel, nurse call light, patient phone, and bedrail). Additionally, the top three areas for cleanliness were identical between the two methods (main light switch, mattress, and bathroom interior door handle). Overall, quantitative microbiology andATPanalysisshowed directional agreement in assessment of environmental cleanliness with higher ATP readings found on surfaces designated as ‘dirty' by quantitative microbiology. Several organisms of concern for hospital infection control were seldomdetected in the pre-cleaning environmental samples, and not at all in the post-cleaning samples. Conclusions In this study environmental bioburden decreased after cleaning, and few hazardous nosocomial organisms were noted. Although quantitative microbiology and ATP detection measure somewhat different aspects of environmental contamination, they both generally agree in distinguishing clean from dirty surfaces.
On the utility and distinctness of the concept of behavioral equipoise.

In their paper, “Behavioral Equipoise: A Way to Resolve Ethical Stalemates in Clinical Research,” Peter Ubel and Robert Silbergleit (2011) argue that the traditional concept of clinical equipoise i...
The influence of sulfate ions on the surface enhanced raman spectra of passive films formed on iron

Abstract Surface enhanced Raman (SER) spectra were obtained from the passive films formed on iron in aqueous solutions of sulfate (pH 5 and pH 10) andborate + sulfate. The results indicate that the identities of the passive films are dependent on the pH of the solution, the identity of the anions present and the potential of iron. Either Fe(OH) 2 , or a species similar to Fe(OH) 2 and which is produced by the oxidation of Fe(OH) 2 , was present in all the films including those formed in the active region of the sulfate solution at pH 5. In the passive state additional species were present but could not always be unambiguously identified. The passive films formed in the sulfate solutions of pH 5 and pH 10 appeared to contain a mixture of Fe 3 O 4 and γ-Fe 2 O 3 . In thesulfate + borate solution the passive film contained α-Fe 2 O 3 . The widths of the peaks in the SER spectra suggested that the constituents in the films were either microcrystalline or amorphous. In addition, in all solutions examined sulfate ions and, when present in the bulk solution, borate ions, appear to adsorb on the surface of the passive films. In the case of the films formed in the sulfate solution of pH 5, sulfate ions were covalently bonded in the films in a bidentate configuration.
How to Determine Your Gas Mileage

So all we have to do is fill up the tank, drive around a bit, refill the tank, and then divide the miles driven by the amount of gas we put into the tank the second time. The trouble with this approach is that gas mileage varies a great deal with driving conditions. In particular, gas mileage in the city is generally much lower than that on the highway. We really want to determine two gas mileages: one for the city and one for the highway. If each time between filling the tank, the car is driven only in the city or only on the highway, then there isn't any problem, but generally between fuelings we do both city and highway driving. We want a method that can handle this situation. We will present such a method below using least squares. This method is suitable for inclusion in a linear algebra course and is quite satisfactory in practice. However, it is not optimal. Improving the method will lead us naturally to the introduction of weighted least squares. Good references for the elementary linear algebra used in this paper include [1] and [2]. To obtain the data needed to apply the method described below, the fuel tank must sometimes be filled completely so that we know how much gas has been used. In addition, the driver must record:
TGFβ inducible early gene‐1 (TIEG1) and cardiac hypertrophy: Discovery and characterization of a novel signaling pathway

Cellular mechanisms causing cardiac hypertrophy are currently under intense investigation. We report a novel finding in the TGFβ inducible early gene (TIEG) null mouse implicatingTIEG1 in cardiac hypertrophy. The TIEG−/− knock-out mouse was studied. Male mice age 4–16 months were characterized (N = 86 total) using echocardiography, transcript profiling by gene microarray, and immunohistochemistry localized upregulated genes for determination of cellular mechanism. The female mice (N =40) did not develop hypertrophy or fibrosis. The TIEG −/− knock-out mouse developed features of cardiac hypertrophy including asymmetric septal hypertrophy, an increase in ventricular size at age 16 months, an increase (214%) in mouse heart/weight body weight ratio TIEG−/−, and an increase in wall thickness in TIEG−/− mice of (1.85 ±0.21 mm), compared to the control (1.13 ±0.15 mm, P< 0.04). Masson Trichrome staining demonstrated evidence of myocyte disarray and myofibroblast fibrosis. Microarray analysis of the left ventricles demonstrated that TIEG−/− heart tissues expressed a 13.81-fold increase in pituitary tumor-transforming gene-1 (Pttg1). An increase in Pttg1 and histone H3 protein levels were confirmed in the TIEG−/− mice hearts tissues. We present evidence implicating TIEG and possibly its target gene, Pttg1, in the development of cardiac hypertrophy in the TIEG null mouse.
Soil properties and microbial activity across a 500 m elevation gradient in a semi-arid environment

If climate change causes the semi-arid shrub-steppe to become hotter and drier it may affect soil C and N cycling and precipitate changes in soil processes and microbial and plant community structure. This study was conducted, using an elevation gradient as an analog of climate change, to analyze climatic influence on soil microbial activity and soil properties. We collected soil from under cryptogamic crust and bunchgrass plants at 25 sites over a 500 m elevation transect in a shrub-steppe ecosystem located in eastern Washington State of the US. The samples were analyzed for several chemical and microbiological attributes including pH, microbial biomass and nitrification potential and the data grouped into five climate sites for statistical analysis. Soil pH decreased over the transect with higher pH values in the grass soil than the crust. In contrast soil electrical conductivity (EC) increased with increasing elevation as did both ammonium and nitrate. Ammonium and EC were greater in the crust soil than the grass soil but nitrate concentration was the same under both plant covers. Both total C and N amounts increased with elevation as did nitrification potential. Due to high sample spatial variability microbial biomass, respiration and N mineralization showed non-significant trends over the 500 m elevation transect. Using these measured gradient relationships the increase in temperature and decrease in precipitation that is expected in this shrub-steppe ecosystem over the next 100 years would eventually cause the pH to increase and the EC to decrease. Plants would become more sparse, nitrification potential would decrease and ammonium would increase. Total C, N and microbial biomass concentrations would begin decreasing and may shift the controlling factors of the ecosystem to abiotic factors. The changes in the cycling of N and to some extent C due to climate change could alter the microbial and plant community structure and function of this ecosystem and cause it to move in the direction of desertification.
What May the Future Hold for Histotechnologists

The hospital-based histology laboratory experienced several changes in the 1960s and 1970s when cryostats, enclosed tissue processors, plastic cassettes, and disposable knives were introduced. Other than the emergence of immunohistochemistry in the 1980s, few major changes have occurred. But now, driven by costs, higher expectations, and a desire for faster turnaround times, these laboratories are on the brink of changes that will involve additional new duties for the pathologist and the histotechnologist. New techniques, some already in use in some hospitals, will involve flow cytometry, fluorescence in situ hybridization (FISH), DNA and genetics studies, proteomics, telepathology, and digital imaging. New antibodies in immunohistochemistry and new biomarkers will assist in diagnoses. Accrediting agencies will raise their standards to meet the new challenges. Although no one really knows what will happen in the future, this article reviews the new changes that will likely occur in hospital histology, based on present predictions and technology. * Abbreviations : FISH : fluorescence in situ hybridization IHC : immunohistochemistry H&E : hematoxylin and eosin CAP : College of American Pathologists ACIS : Automated Cellular Imaging System JCAHO : Joint Commission on Accreditation of Healthcare Organizations CMS : Centers for Medicare and Medicaid Services CLIA : Clinical Laboratory Improvement Amendments TATs : turnaround times UPMC : University of Pittsburgh Medical Center ER/PR : estrogen receptor/progesterone receptor HER2 : human epidural growth factor receptor 2 PSA : prostate-specific antigen CA : carbohydrate antigen
Ranging and recognition of small targets in compressed stereoscopic imagery: I. Background and theory

The processing of compressed data generally yields decreased computational cost, due to the requirement of fewer operations in the presence of fewer data. We have previously shown that the automated recognition of small targets in compressed imagery, called compressive ATR, is feasible for a variety of compressed image formats. For example, images having domain size X , when tesselated into k X l-pixel blocks and processed by a block-compression transform such as vector quantization (VQ), have compressed domain size V equals X kl pixels. The characterization of each k X l pixel block in terms of one or more parameters of a compressed pixel facilitates the processing of O(Y) such pixels in O(CRD) equals O(X/Y) equals O(kl) work, where CRD denotes the domain compression ratio. In practice, typical computational efficiencies of approximately one-half the domain compression ratio have been realized via processing imagery compressed by VQ, block truncation coding (BTC), and visual pattern image coding (VPIC). In this paper, we extend our previous research in compressive ATR to include the processing of compressed stereoscopic imagery. We begin with a brief review of stereo vision and the correspondence problem, as well as theory fundamental to the processing of compressed data. We then summarize VQ, BTC, and VPIC compression. In Part 2 of this series, we map a cepstrum- based stereo matching algorithm to stereoscopic images represented by the aforementioned compressive formats. Analyses emphasize computational cost and stereo disparity error. Algorithms are expressed in terms of image algebra, a rigorous, concise notation that unifies linear and nonlinear mathematics in the image domain. Since image algebra has been implemented on numerous sequential and parallel computers, our algorithms are feasible and widely portable.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A regional perspective on biotic change during the Classic Maya occupation using zooarchaeological isotopic chemistry

This paper uses stable isotopic research on faunal remains from archaeological sites in the Maya area to describe ancient environments through time in the region. Carbon isotope signatures of white-tailed deer remains recovered from the Petexbatun and Motul de San Jose polities in Guatemala are combined with other published data to provide a regional diachronic perspective on variations in availability of maize, a C4 plant, to herbivores. These data are used as a proxy for the extent of agricultural fields through time across the Maya world and the results indicate considerable temporal and spatial heterogeneity, likely linked to natural environmental heterogeneity and local land-use histories. The local nature of variations underscores the need for greater detail in paleoenvironmental studies at the drainage-basin or site level. Preliminary oxygen isotope research on white-tailed deer from the Motul de San Jose polity is also presented as the basis for discussion of the role of archaeologically linked oxygen isotope signatures in correlating large scale climate shifts with other site-specific evidence for environmental change over the period of Maya occupation. Together discussions of the two isotopic data sets emphasize the importance of paleoenvironmental and particularly isotopic research on materials from well-dated archaeological contexts.
Effects of multiple courses of antenatal betamethasone on the auditory brainstem responses of premature infants.

We thank Dr Church for his letter regarding our observational study on the effect of multiple courses of antenatal betamethasone on auditory neural maturation. We are glad to see that he also found no effect on auditory neural maturation after exposure to multiple courses of antenatal betamethasone. These findings provide external validity to our findings. To help Dr Church prepare his manuscript, we have attempted to clarify and answer the questions that he raised. 1. The median number of betamethasone courses given to the pregnant women …
Composite fermions in the neighborhood of ν = 1/3

Abstract We present extensive comparisons of the composite fermion theory with exact results in the filling factor range 2/5>ν>1/3, which affirm that the composite fermion theory correctly describes the qualitative reorganization of the low energy Hilbert space of the strongly correlated electrons, and predicts eigenenergies with an accuracy of ∼0.1%. These facts establish the basic validity of the composite fermion description in this filling factor region.
Synchronization in Ratings of Pubertal Maturity and Faulty Beliefs about Family Relationships.

Faulty beliefs are associated with the realignment of family relationships during the child's physical transition into early adolescence. These beliefs reflect problems in understanding interpersonal relationships within the family.
Delayed preconditioning-mimetic actions of nitroglycerin in patients undergoing exercise tolerance tests.

Background— Nitroglycerin (NTG) induces delayed preconditioning (PC)-mimetic effects in animal models and in humans during coronary angioplasty. We tested the hypothesis that NTG mitigates ischemia and enhances functional capacity during an exercise tolerance test (ETT) in patients with coronary artery disease. Methods and Results— Twenty-eight patients with stable angina and ischemia documented by a stress test were randomized in a double-masked, crossover design to receive a titrated intravenous infusion of NTG or normal saline over 4 hours. At 24 to 28 hours after study medication infusion, each patient underwent 2 ETTs separated by a 1-week washout period. Compared with control patients, pretreatment with NTG was associated with a dose-dependent increase in exercise duration averaging 40 seconds (412±19 versus 372±24 seconds, P=0.014) and an improvement in ECG manifestations of ischemia, as shown by a decrease in maximal ST-segment depression (1.84±0.14 versus 1.63±0.13 mm, P=0.011), sum of ST-segment...
Purification and characterization of an extracellular β-glucosidase from the rumen fungus Neocallimastix frontalis EB188

Abstract An extracellular β-glucosidase (E3.2.1.21) from the rumen fungus Neocallimastix frontalis EB188 was purified. The purification protocol included hydroxylapatite, gel filtration, and ion exchange chromatographies and native polyacrylamide gel electrophoresis. The enzyme readily hydrolysed p-nitrophenyl (pNP) β- d -glucopyranoside, and cellobiose, but not a variety of other substrates. Activity was inhibited by glucose ( K i = 10.5 m m ) and glucono-δ-lactone ( K i = 0.24 m m ). Activity was inhibited in the presence of certain metal ions and stimulated by dithiothreitol. The enzyme had a denatured molecular weight of 125,500 daltons and possessed an isoelectric focusing point of 7.10. Using pNP β- d -glucopyranoside as substrate, the Km and Vmax values of the enzyme were 2.5 m m and 5.02 IU mg−1, respectively. The temperature optimum of the activity was 45°C. The enzyme was rapidly inactivated at 65°C. The pH activity optimum occurred broadly between 5.5 and 7.0.
Transfer RNA chromatography on reversed phase five: Effect of cadimum ion on a queuine-type tRNA*

Summary A sensitive method is described that detects an alteration in the structure of tRNA that is caused by cadmium but not by magnesium or zinc ions. The chromatographic system, RPC-5, separates Drosophila tyrosyl-tRNA into two fractions. These two isoacceptors differ by a single position in the anticodon where either a guanosine or queuine resides. Cadmium ions apparently interact with the tRNA and prevent the chromatographic separation. This is the first instance where cadmium is shown to cause a selective change in nucleic acid structure. The RPC-5 system seems to be uniquely useful in detecting such a change.
My Career as a Radioisotope Hunter

My career as a radioisotope hunter began when I was working as a young scientist in the Radiation Laboratory at the University of California, Berkeley, during the trailblazing years in the late 1930s. I started this research in 1936 while a graduate student in the Department of Chemistry at Berkeley. The cyclotrons of Ernest O. Lawrence opened the doors to discovery, and as a chemist I was in the enviable position of being able to apply the powerful methods of my discipline to the identification of transmutation products. As a result of the broad interests of Ernest and his brother John, the scope of investigations in the Radiation Laboratory extended beyond basic research to include the practical interdisciplinary applications of these new tools of investigation. Special emphasis was placed on applications to medicine. Partly because of this and partly as a result of accidental good fortune, I became involved in
A human fibrosarcoma cell line producing multiplication stimulating activity (MSA)-related peptides

WE suggested previously that transformed cells may produce and release cellular growth factors capable of interacting with a specific class of cellular receptors, making them unavailable as receptors for external ligands1,2. A prediction of this model was that a human fibrosarcoma line, which had been shown not to bind 125I-labelled multiplication stimulating activity (MSA)2, might be secreting molecules functionally related to MSA. We describe here some properties of growth factors produced by this human tumour cell line, derived from a 25-yr-old female with fibrosarcoma of the leg. The cells produce a family of MSA-related compounds with different molecular weights that can be separated on Sephadex G-75. The major activities correspond to proteins of approximate molecular weight (MW) of 11,000 and 7,000. Both of these fractions stimulate cell division, and will compete with 125I-labelled MSA for its receptors on mouse, rat or human cell membranes. Fibrosarcoma cells in culture may constitute an important alternate source to human serum and plasma for the isolation and characterisation of growth stimulating factors.
Women's roles and women's health: The effect of immigration on latina women

S everal articles in the literature address the health beliefs and practices of immigrant Latinos. It is well established that a woman’s roles, and her ability to carry them out, have a significant effect on her health and the health of her family. As a clinician caring for immigrant women from Mexico, I sought to consider how Latina women’s health and the health of their families may be impacted by the immigration process itself. Data on the effects of international migration are scant.’ In the United States, female immigrants outnumber male immigrants. These women face a number of barriers, including language difficulties, nationality differences, gender bias, limited skills or resources, physical dangers, and the absence of family or other social support networks. Overcoming these barriers requires women to make numerous adjustments in their many roles and has been identified as an area in which additional research is needed.* The necessity for further research is evident when one considers that most health concerns of women are enmeshed with the financial and social aspects of their lives. Social science research relating to women’s health must continue and must be complemented by traditional biomedical model approaches. I draw from clinic experiences and present selected research findings in order to illustrate the implications of immigration on the roles of Mexican women in the United States. With the effects of immigration becoming a growing concern, my goal is to affirm the importance of this type of research and to encourage clinicians and planners to consider socioeconomic issues when developing health programs targeting women.
Hepatitis C in the HIV-Infected Person

Because of shared routes of transmission, hepatitis C virus (HCV) infection is common in HIV-infected persons, who have been experiencing increasing HCV-related morbidity and mortality since the advent of effective antiretroviral therapy. Infection with HIV appears to adversely affect the outcome of hepatitis C, leading to increased viral persistence after acute infection, higher levels of viremia, and accelerated progression of HCV-related liver disease. In addition, hepatitis C may affect the course and management of HIV infection. The medical management of hepatitis C in HIV-infected persons is complicated by immune suppression, potential drug interactions and toxicities, and other forms of liver disease. In addition, there is little published experience with the safety and efficacy of the best available anti-HCV medications in HIV-infected persons. Thus, current efforts must be directed at preventing HCV and HIV infections and applying the principles learned in treating persons with either infection to manage those with both. Future efforts should include studies of the pathogenesis of HCV infection in HIV-infected persons and large, prospective studies that demonstrate the optimal management of persons co-infected with HIV and HCV. Such efforts will help to eliminate HCV-related liver disease as an emerging threat to HIV-infected persons.
Defining the mechanism by which IFN-|[beta]| dowregulates c-myc expression in human melanoma cells: pivotal role for human polynucleotide phosphorylase (hPNPaseold-35)

Type I interferons (IFN-α/-β) are capable of suppressing c-myc mRNA expression by modulating post-transcriptional processing. However, the molecular mechanism of this phenomenon is poorly understood. We previously established that human polynucleotide phosphorylase (hPNPaseold-35), a type I IFN-inducible 3′,5′ exoribonuclease involved in mRNA degradation, induces G1 cell cycle arrest and eventually apoptosis by specifically degrading c-myc mRNA. We now demonstrate a close association between IFN-β-induced hPNPaseold-35 upregulation and c-myc downregulation in human melanoma cells. Employing stable melanoma cell clones expressing hPNPaseold-35 small inhibitory RNA, we demonstrate that hPNPaseold-35 is a key molecule coupled with IFN-β-mediated downregulation of c-myc mRNA. Inhibition of hPNPaseold-35 or overexpression of c-myc protects melanoma cells from IFN-β-mediated growth inhibition, emphasizing the importance of hPNPaseold-35 upregulation and consequent c-myc downregulation in IFN-β-induced growth inhibition and apoptosis induction. In these contexts, targeted overexpression of hPNPaseold-35 might be a novel therapeutic strategy for c-myc-overexpressing and IFN-resistant tumors, such as melanomas.
Henneguya adiposa Minchew (Myxosporida) in the Channel Catfish: Ultrastructure of the Plasmodium Wall and Sporogenesis*

SYNOPSIS Wall ultrastructure and sporogenesis were studied in plasmodia of Henneguya adiposa Minchew which infects the channel catfish, Ictalurus punctatus (Rafinesque). Plasmodia were located among connective tissue bands of the adipose fin and were always separated from host fibrocytes by collagen fibers. The plasmodium wall consisted of a single unit membrane which was continuous with numerous pinocytic canals extending into the parasite's ectoplasm. The membrane was highly convoluted, producing an irregular parasite surface, and was covered by a fine granular coat of almost uniform thickness. Early sporogenic stages were located in a zone of cytoplasm rich in mitochondria, just interior to the zone of pinocytic canals. Later sporogenic stages, including mature spores, were concentrated in the center of the plasmodia. Sporogenesis began with the envelopment of one generative cell, the sporont, by a 2nd, nondividing, cell—the enveloping cell. The sporont and its progeny proceeded through a series of divisions until 10 cells were present within the enveloping cell. Once divisions were completed, the 10 cells became arranged into 2 identical spore-producing units, each consisting of one binucleate sporoplasm and 2 capsulogenic cells, all surrounded by 2 valvogenic cells. Later stages of spore development indicated that capsulogenesis, valvogenesis and sporoplasm maturation occurred concomitantly.
Effect of Transforming Viruses on Molecular Mechanisms Associated With Cancer

Viruses have been linked to approximately 20% of all human tumors worldwide. These transforming viruses encode viral oncoproteins that interact with cellular proteins to enhance viral replication. The transcriptional and post-transcriptional effects of these viral oncoproteins ultimately result in cellular transformation. Historically, viral research has been vital to the discovery of oncogenes and tumor suppressors with more current research aiding in unraveling some mechanisms of carcinogenesis. Interestingly, since transforming viruses affect some of the same pathways that are dysregulated in human cancers, their study enhances our understanding of the multistep process of tumorigenesis. This review will examine the cellular mechanisms targeted by oncogenic human viruses and the processes by which these effects contribute to transformation. In particular, we will focus on three transforming viruses, human T-cell leukemia virus type-I, hepatitis B virus and human papillomavirus. These viruses all encode specific oncogenes that promote cell cycle progression, inhibit DNA damage checkpoint responses and prevent programmed cell death in an effort to promote viral propagation. While the transforming properties of these viruses are probably unintended consequences of replication strategies, they provide excellent systems in which to study cancer development.
Disruption of rabbit (Oryctolagus cuniculus) nictitating membrane conditioning by posttrial electrical stimulation of hippocampus.

Abstract Two experiments were conducted involving classical conditioning of the nictitating membrane response of rabbits with posttrial electrical brain stimulation. Hippocampal posttrial stimulation (PTS) presented immediately after each CS-US paired trial was found to cause massive disruption of conditioning by comparison with performance of either a cortical PTS group, an operated but unstimulated group, or an unoperated control group. The major effect of PTS was to postpone CR emergence. Once CRs began to occur, conditioning seemed to proceed normally regardless of the presence or absence of stimulation. Hippocampal PTS initiated after conditioning had no effect on the elicitation of conditioned responses. The results indicated that hippocampal PTS disrupted consolidation but did not affect either registration of stimuli or execution of unconditioned or conditioned responses. It was concluded that classical conditioning of the rabbit nictitating membrane response is an excellent model neural system for the investigation of neurophysiological aspects of memory.
BRAF V599E Mutation is Not Age Dependent: It is Present in Common Melanocytic Nevi in Both Children and Adults

BRAF encodes a serine-threonine kinase, which acts in the RAS/RAF/MAPK pathway transducing regulatory signals from RAS to MEK1/2. Somatic mutations in BRAF have been identified in 53–80% of primary melanomas and 70–90% of common melanocytic nevi. More than 90% of these mutations consist of a valine to glutamate substitution at codon 599 (V599E) of exon 15. While a high prevalence of BRAF mutations in common melanocytic nevi has been reported in adults, nevi in children have not been studied. Of interest, we have previously shown that Spitz nevi in children do not harbor mutations in BRAF. To investigate the association of BRAF mutations with patient age, we studied common melanocytic nevi in children for the V599E activating mutation. Tumor cells were microdissected from 6 common melanocytic nevi in children 10 years of age or younger, and analyzed for the V599E mutation in BRAF by allele-specific PCR and gel electrophoresis. In 6 of 6 (100%) nevi, the V599E mutant allele was observed. Our data suggest that similar genetic pathways are involved in the development of common melanocytic nevi in children and adults. The absence of BRAF mutations in Spitz nevi in children is therefore associated with tumor type, not patient age.
Time-Dependent Deposition Characteristics of Fine Coal Fly Ash in a Laboratory Gas Turbine Environment

Time-dependent deposition characteristics of fine coal flyash were measured in the Turbine Accelerated Deposition Facility (TADF) at Brigham Young University. Two samples of subbituminous coal fly ash, with mass mean diameters of 3 and 13 μm, were entrained in a hot gas flow with a gas temperature of 1250°C and Mach number of 0.25. A nickel base super alloy metal coupon approximately 0.3 cm thick was held in a hot particle-laden gas stream to simulate deposition in a gas turbine. Tests were conducted with deposition times of 20, 40, and 60 minutes. Capture efficiencies and surface roughness characteristics (e.g., Ra) were obtained at different times. Capture efficiency increased exponentially with time while Ra increased linearly with time. The increased deposition with time caused the surface temperature of the deposit to increase. The increased surface temperature caused more softening, increasing the propensity for impacting particles to stick to the surface. These data are important for improving models of deposition in turbines from syngas flows.Copyright © 2011 by ASME
Efficient interconnection designs for switch-based local area networks

This paper presents a study of efficient arrangements of switches intended to support a local area network environment. Given a set of switches, the goal is to find the interconnection pattern which maximizes the number of simultaneous connections the network can support. Various configurations of switches are evaluated and compared. The results of this paper may be applied to any set of connection-oriented switches, e.g., ATM, HIPPI.