cssi/SciSciGPT-SciSciNet huggingface dataset:
Polynomial-Length Planning Spans the Polynomial Hierarchy

This paper presents a family of results on the computational complexity of planning: classical, conformant, and conditional with full or partial observability. Attention is restricted to plans of polynomially-bounded length. For conditional planning, restriction to plans of polynomial size is also considered. For this analysis, a planning domain is described by a transition relation encoded in classical propositional logic. Given the widespread use of satisfiability-based planning methods, this is a rather natural choice. Moreover, this allows us to develop a unified representation--in second-order propositional logic--of the range of planning problems considered. By describing a wide range of results within a single framework, the paper sheds new light on how planning complexity is affected by common assumptions such as nonconcurrency, determinism and polynomial-time decidability of executability of actions.
Demonstration of differential virulence gene promoter activation in vivo in Bordetella pertussis using RIVET.

Summary Bordetella pertussis, the etiologic agent of whooping cough, causes disease by employing an array of virulence factors controlled by the BvgA–BvgS two-component signal transduction system. Regulation by this system has been extensively characterized in vitro, where bvg-activated genes are repressed in a process known as phenotypic modulation. Differential regulation of these genes by the response regulator BvgA results in promoters that are activated early, middle, or late after being released from modulation. However, the in vivo environmental signal and regulation pattern has not been described. In order to investigate BvgAS-mediated regulation of B. pertussis virulence factors in vivo using the mouse aerosol challenge model, we have adapted the recombinase-based in vivo technology (RIVET) system for use in B. pertussis. We have demonstrated that these strains show resolution during in vitro growth under non-modulating conditions. In addition, we have demonstrated that modulating strains by growth on media containing MgSO4 does not affect virulence in the mouse aerosol challenge model. We have therefore used the RIVET system to reveal the time-course of gene expression in vivo for selected B. pertussis virulence factors (cya, fha, prn and ptx). Our data indicate that this method can be effectively used to monitor and compare in vivo and in vitro gene expression in B. pertussis, and that temporal regulation patterns previously observed in vitro are mirrored in vivo.
The Security of Securitization and the Future of Security

The securitization of mortgage loans and other receivables benefits society and rests on a strong legal foundation. Securitization lowers the financing costs for borrowers and originators of loans by avoiding the costs imposed by the Bankruptcy Code on the secured creditors of operating companies. This article demonstrates how securitization avoids these costs by combining two long recognized legal devices, (1) a true sale of receivables to a buyer (2) that is a separate legal entity whose sole purpose is to finance the receivables. This structure separates the risks associated with the receivables, which creditors can more easily assess, from the murkier risks associated with an operating company.
Story and Real Life

Why should we be concerned about the fate of literature as we move from a book culture to a screen culture in the digital age? Not primarily because we are losing our sense of story, but because we are losing our sense of the central importance of linguistic narrative. There is a difference. The technologies creating the digital revolution seem to devalue language and increasingly to do away with boundaries, celebrating instead speed and boundless exhilaration. The visual trumps the linguistic, the image and the screen trump the word and the book. As a result, we no longer seem to engage deeply with others or ourselves. We are beginning to move, in other words, from “a reading brain” to “a digital brain,” from a brain capable of deep reading and deep thinking to a brain increasingly addled by spectacle and surface sensation. We are losing our standing as “linguistic beings.”
Praxisbeispiel Motorola: Diversity-orientierte Vergütung

Zu Beginn des Jahres 2011 wurde Motorola Inc. in zwei unabhangige borsennotierte Unternehmen aufgespalten, die Motorola Mobility Inc. und die Motorola Solutions Inc. Dies erfordert eine Analyse und Neudefinition zahlreicher Unternehmensbereiche samt ihrer Strategien und Praktiken, ein Prozess, der zur Zeit der Drucklegung dieses Buchs noch nicht abgeschlossen war. Dies betrifft auch die im Folgenden dargestellte Diversityorientierte Vergutung und ihre Einbettung in die Diversity & Inclusion-Strategie, die darum in der Form beschrieben wird, wie sie in den Jahren 2006 bis 2010 im Unternehmen Motorola praktiziert wurde.
A tutorial on design analysis using von Mises stress in random vibration environments

The von Mises stress is often used as the metric for evaluating design margins, particularly for structures made of ductile materials. While computing the von Mises stress distribution in a structural system due to a deterministic load condition may be straightforward, difficulties arise when considering random vibration environments. As a result, alternate methods are used in practice. One such method involves resolving the random vibration environment to an equivalent static load. This technique, however, is only appropriate for a very small class of problems and can easily be used incorrectly. Monte Carlo sampling of numerical realizations that reproduce the second order statistics of the input is another method used to address this problem. This technique proves computationally inefficient and provides no insight as to the character of the distribution of von Mises stress. This tutorial describes a new methodology to investigate the design reliability of structural systems in a random vibration environment. The method provides analytic expressions for root mean square (RMS) von Mises stress and for the probability distributions of von Mises stress which can be evaluated efficiently and with good numerical precision. Further, this new approach has the important advantage of providing the asymptotic properties of the probability distribution. A brief overview of the theoretical development of the methodology is presented, followed by detailed instructions on how to implement the technique on engineering applications. As an example, the method is applied to a complex finite element model of a Global Positioning Satellite (GPS) system. This tutorial presents an efficient and accurate methodology for correctly applying the von Mises stress criterion to complex computational models. The von Mises criterion is the traditional method for determination of structural reliability issues in industry.
HBe-Antigen in the course and prognosis of hepatitis B infection: a prospective study.

Abstract The prognostic significance of the HBe-antigen (HBeAg) in the course and outcome of type B hepatitis was studied prospectively in 71 susceptible oncology patients. The patients had been exposed to tumor cell vaccines inadvertently contaminated with hepatitis B surface antigen (HBsAg)-containing plasma. Forty-five patients (63%) were infected. These 45 showed three types of acute seroresponse: HBsAg and HBeAg, 28 patients (62%); HBsAg alone, 8 patients (18%); and a primary antibody to HBsAg (anti-HBs) response, 9 patients (20%). There was no significant difference in acute course and outcome between the two HBs-antigenemic groups. All primary anti-HBs responders had asymptomatic infections. Seventeen patients receiving chemotherapy during the period of hepatitis B exposure were significantly more prone to symptomatic infection with acute HBs-antigenemia, and 2 of these patients developed chronic active hepatits. The HBeAg is common early in acute hepatitis B among solid tumor patients and at this stage in disease has no prognostic significance independent of HBsAg.
Workforce Analysis in Orthopaedic Surgery: How Can We Improve the Accuracy of Our Predictions?

Since the 1970s, workforce analysis for orthopaedic surgery has predicted a surplus of physicians into the 21st century. In 1998, the RAND study predicted a surplus of 4,100 orthopaedists in 2010. As we approach 2010, we find no surplus. The projected population growth during the next 20 years of those older than age 65 years presupposes a greater need for orthopaedists, given an increase in degenerative disease and fragility fractures associated with aging. The federal government predicts an overall shortage of physicians by 2020. Given the current nature of workforce analysis models and the concerns evoked by these disparate predictions, we, the authors, advocate change. Rather than large studies separated by decades, we recommend routine monitoring of the orthopaedic workforce. Further, we suggest that national, regional, and local organizations, as well as subspecialty societies, work together to monitor current and future orthopaedic workforce needs. Orthopaedic organizations should develop collaborative relationships with experts in the field and devise a true working model that allows for ongoing strategic planning.
Mean squared error bounds for the Rangan–Goyal soft thresholding algorithm

The Rangan–Goyal (RG) algorithm is an iterative method, based on soft thresholding, for constructing an estimate xN∈Rd of a signal x∈Rd, given N⩾d frame coefficients of x that have been corrupted by uniform noise. It has been proven by Rangan and Goyal that for every p<1, the RG-algorithm has reconstruction error that satisfies limN→∞‖x−xN‖Np=0 almost surely, where the randomization is taken over the choice of frame and the corrupting noise sequence. It is proven here that the RG-algorithm achieves mean squared error (MSE) of the optimal order E‖x−xN‖2⩽C/N2 in the setting of random frames. There are, however, concrete scenarios where the algorithm performs poorly for specific (deterministically chosen) frames. The issue of frame ordering plays an important role in the deterministic setting. It is shown here that for suitable orderings of deterministic frames the RG-algorithm has reconstruction error E‖x−xN‖2⩽C/N2, where the expectation only involves the corrupting noise sequence and where C is an explicit constant.
Purification of tyrosine aminotransferase by affinity chromatography.

Abstract Tyrosine aminotransferase ( l -tyrosine:2-oxoglutarate amino transferase, EC 2.6.1.5) will bind to affinity adsorbents containing covalently bound pyridoxamine phosphate. It can be released by a change of buffers with a resultant 125-fold purification. The enzyme can be further purified by chromatography on Sephadex G-200 to give a product with a specific activity of 400 enzyme units/mg protein. This method apparently copurifies different isozymes of tyrosine aminotransferase.
A novel technique for the preparation of thin films for cross‐sectional transmission electron microscopy

A method is described for the preparation of cross-sectional samples of thin films for transmission electron microscopy. The technique produces larger amounts of thin region as compared with ion milling and eliminates the problems associated with ion beam damage. The requirement is that the films or multilayers must initially be deposited on a water-soluble substrate such as single-crystal NaCl.
Typing on Glasses: Adapting Text Entry to Smart Eyewear

Text entry for smart eyewear is generally limited to speech-based input due to constraints of the input channels. However, many smart eyewear devices are now including a side touchpad making gesture-based text entry feasible. The Swipeboard technique, recently proposed for ultra-small touch screens such as smart watches, may be particularly suitable for smart eyewear: unlike other recent text-entry techniques for small devices, it supports eyes-free input. We investigate the limitations and feasibility of implementing Swipeboard on smart eyewear, using the side touch pad for input. Our first study reveals usability and recognition problems of using the side touch pad to perform the required gestures. To address these problems, we propose SwipeZone, which replaces diagonal gestures with zone-specific swipes. In a text entry study, we show that our redesign achieved a WPM rate of 8.73, 15.2% higher than Swipeboard, with a statistically significant improvement in the last half of the study blocks.
DOE funds Gizmos

The U.S. Department of Energy (DOE) will give $4.8 million to 21 U.S. universities for new instruments for energy-related research, it was announced last week. The 24 successful proposals were selected from 188 applications. Four of the University Research Instrumentation Awards are designated for geoscience research. The minute sources of remanent magnetization in rocks will be investigated by John Geissman of the Univeristy of New Mexico in Albuquerque (UNM) with a magnetometer of special design, funded by a DOE grant of $115,000. Paleomagnetic measurements are generally based on a bulk determination of magnetization of 11 cm3 or so of rock. “But the size of particles that are the source of geologically stable remanent magnetism is very small,” says Geissman. His magnetometer is designed to analyze particles as small as a micron. It will be used with a scanning/transmission electron microscope (STEM) at UNM to explore where the small grains reside in rocks and to gain a fuller understanding of the paleomagnetism measured by conventional means. Future work may also involve using a laser to destroy selected magnetic phases and minimize the effects of parts of the magnetic mineralogy, permitting examination of any magnetic material that remains.
MRI Measurement of Hepatocyte Toxicity Using the New MRI Contrast Agent Manganese Dipyridoxal Diphosphate, a Manganese/Pyridoxal 5‐Phosphate Chelate

This study reports the first in vivo results using an MR contrast agent manganese dipyridoxal diphosphate (Mn-DPDP) designed to estimate the functional status of the hepatocyte. Thirty New Zealand white rabbits were studied in groups of 5 as follows: No. 1, control, MRI scans only; No. 2 MRI before and up to 90 min following 50 μmol/kg of Mn-DPDP iv; No. 3, rabbits received 9.3 g ethanol/kg and MRI; No. 4, as in No. 3 but following Mn-DPDP; No. 5, MRI as in No. 2 but 18 h. following 1000 mg/kg Dgalactosamine used to induce hepatocyte necrosis; and No. 6, rabbits received D-galactosamine and Mn-DPDP. In this study significant ethanol-and D-galactosamine-induced hepatocyte damage was indicated by the increased SGPT serum levels in the rabbit. The use of Mn-DPDP allowed detection of early hepatocyte necrosis in these animals whereas conventional spin-echo MRI did not. The fact that D-galactosamine curves with and without Mn-DPDP were not significantly different indicated virtually no membrane transport or metabolism of Mn-DPDP in the liver. Ethanol curves were not normal, but there was still considerable residual Mn-DPDP metabolism. Mn-DPDP appears to be an attractive agent in assessing hepatocyte function. © 1989 Academic Press, Inc.
Chromatography on Water−Ice

Ice contains a thin film of water on its surface, the thickness ranging from nanometer to micrometer levels, depending on the bulk temperature and the composition of the solution used in making the ice. It follows that water held on the surface of an ice particle should endow a column packed with microparticulate ice the properties of a chromatographic column containing a pellicular packing. We demonstrate here the normal phase separation of two dyes on a column packed with millimeter-size ice particles, held at -18 °C.
Infrared-radiofrequency double-resonance spectroscopy of CD3Br

Abstract An infrared microwave sideband laser source operating in the 10 μm region has been used with the method of infrared-radiofrequency double resonance to record radiofrequency spectra in the ground and ν 2 =1 vibrational states of CD 3 Br. The frequencies to ∼200 and ∼160 pure quadrupole transitions have been observed for CD 3 79 Br and CD 3 81 Br, respectively, approximately half in the ground state and half in the ν 2 =1 vibrational state of each species. The frequencies have been used to determine the quadrupole coupling constants, including centrifugal distortion parameters, and spin-rotation constants for the bromine nucleus in each species. A double-resonance effect that causes an apparent shift in frequency for each of a pair of closely-spaced double-resonance transitions has been discovered experimentally and explained theoretically.
Non-intrusive in-service PMD measurements: A novel approach based on coherent detection

We describe a novel method for in-service Polarization Mode Dispersion measurements and compare its accuracy with the Jones matrix eigen-analysis method. A relative accuracy of 4% is reported over a 1–50ps mean DGD range.
Transmission electron microscopy characterization of the fission gas bubble superlattice in irradiated U-7 wt%Mo dispersion fuels

Abstract Transmission electron microscopy characterization of irradiated U–7 wt%Mo dispersion fuel were performed on various U–Mo fuel samples to understand the effect of irradiation parameters (fission density, fission rate, and temperature) on the self-organized fission-gas-bubble superlattice that forms in the irradiated U–Mo fuel. The bubble superlattice was seen to form a face centered cubic structure coherent with the host U–7 wt%Mo body-centered cubic structure. At a fission density between 3.0 and 4.5 × 10 21 fiss/cm 3 , the superlattice bubbles appear to have reached a saturation size with additional fission gas associated with increasing burnup predominately accumulating along grain boundaries. At a fission density of ∼4.5 × 10 21 fiss/cm 3 , the U–7 wt%Mo microstructure starts to undergo grain subdivision and can no longer support the ordered bubble superlattice. The sub-divided fuel grains are less than 500 nm in diameter with what appears to be micron-size fission-gas bubbles present on the grain boundaries. Solid fission products typically decorate the inside surface of the micron-sized fission-gas bubbles. Residual superlattice bubbles are seen in areas where fuel grains remain micron sized. Potential mechanisms of the formation and collapse of the bubble superlattice are discussed.
Recognition of nucleoside triphosphates during RNA-catalyzed primer extension.

In support of the idea that certain RNA molecules might be able to catalyze RNA replication, a ribozyme was previously generated that synthesizes short segments of RNA in a reaction modeled after that of proteinaceous RNA polymerases. Here, we describe substrate recognition by this polymerase ribozyme. Altering base or sugar moieties of the nucleoside triphosphate only moderately affects its utilization, provided that the alterations do not disrupt Watson−Crick pairing to the template. Correctly paired nucleotides have both a lower Km and a higher kcat, suggesting that differential binding and orientation each play roles in discriminating matched from mismatched nucleotides. Binding of the pyrophosphate leaving group appears weak, as evidenced by a very inefficient pyrophosphate-exchange reaction, the reverse of the primer-extension reaction. Indeed, substitutions at the γ-phosphate can be tolerated, although poorly. Thio substitutions of oxygen atoms at the reactive phosphate exert effects similar to tho...
Urban, Suburban, or Rural Location as a Proxy Measure of Need Implications for Targeting Resources to Elders

The author explores findings from the 1986 Longitudinal Supplement on Aging to determine the appropriateness of using proxy variables, including urban/rural location, as indicators of need among elderly residents. The application of regression models using proxies typical for distributional decisions against seven measures of need indicates that biasing in favor of rural elders may be an ineffective strategy. Reliance on proxy measures may result in inefficient and inequitable methods for distribution of funds within states. An expanded definition of need is recommended for distributional decisions.
Evaluating the use of a geographic digital library in undergraduate classrooms: ADEPT

The evaluation plan for the Alexandria Digital Earth Prototype (ADEPT) centers on two investigations: a study of classroom use of the system by faculty and students and lab-based usability studies. The classroom-based study is primarily an investigation of the digital library's impact on student learning, using multiple research methods. The five-year work plan includes investigations of the use of ADEPT in non-geography classes.
Possible use of synthetic surface-active agents for the preparation of tumour cell nuclei.

WHILE the observation has been made that surface-active agents will produce lysis of the plasma membrane of cells1,2, little use seems to have been made of this observation for the preparation of nuclei3. Some preliminary observations suggest that nuclei may be prepared in large numbers from a variety of cells, without the use of special apparatus, by treatment with the anionic surface-active agent, sodium lauryl sulphate. Nuclei prepared in this manner are at least as free from cytoplasm as those prepared by the method of Hogeboom et al. 4. In the case of some tumours, such as the V–2 carcinoma of the rabbit, they are very much cleaner (Figs. 1 and 2).
Enhancement of Resistance against Oxidation with Carbon Dioxide for Formed Coke and Electrode-grade Graphite and Carbon by Infiltrating Carbon into Pores

Formed coke, electrode-grade graphite (E.G.) and elctrode-grade carbon (E.C.) were modified by infiltrating carbon within the pores by use of methane cracking. The rate of oxidation with CO2 was lowered for all these samples but the amount of reduction was dependent on pore structures. Decrease in the rate for the electrode-grade carbon was very large compared to other samples. The mechanism of enhancement of resistance against oxidation was explained in terms of the pore structure changes accompanying infiltration and oxidation.
Compression stress–strain and creep properties of the 52In–48Sn and 97In–3Ag low-temperature Pb-free solders

Lead (Pb)-free, low melting temperature solders are required for step-soldering processes used to assemble micro-electrical mechanical system (MEMS) and optoelectronic (OE) devices. Stress–strain and creep studies, which provide solder mechanical properties for unified creep-plasticity (UCP) predictive models, were performed on the Pb-free 97In–3Ag (wt.%) and 58In–42Sn solders and counterpart Pb-bearing 80In–15Pb–5Ag and 70In–15Sn–9.6Pb–5.4Cd alloys. Stress–strain tests were performed at 4.4 × 10−5 s−1 and 8.8 × 10−4 s−1. Stress–strain and creep tests were performed at −25, 25, 75, and 100°C or 125°C. The samples were evaluated in the as-fabricated and post-annealed conditions. The In–Ag solder had yield stress values of 0.5–8.5 MPa. The values of ΔH for steady-state creep were 99 ± 14 kJ/mol and 46 ± 11 kJ/mol, indicating that bulk diffusion controlled creep in the as-fabricated samples (former) and fast-diffusion controlled creep in the annealed samples (latter). The In–Sn yield stresses were 1.0–22 MPa and were not dependent on an annealed condition. The steady-state creep ΔH values were 55 ± 11 kJ/mol and 48 ± 13 kJ/mol for the as-fabricated and annealed samples, respectively, indicating the fast-diffusion controlled creep for the two conditions. The UCP constitutive models were derived for the In–Ag solder in the as-fabricated and annealed conditions.
Hitchhiking: Social signals at a distance

Hitchhiking is used as a model for the experimental investigation of long range communication. Two studies were conducted to ascertain the importance of sex, eye contact, food, secondary sex characteristics, and hand gestures in hitching a ride. Eye contact was directed either at the driver or along the side of the road. The hitchhiker was either eating or not eating fruit. The secondary sex characteristics were bust size in females and beard growth in males. Either a traditional thumb-up or a palm-up, flexed-fingers begging gesture was utilized. The recorded data include the number of cars passing the hitchhiker, the number of motorists offering rides, their passengers, and the types of vehicles they were driving. The findings suggest that the effective signals in hitching a ride are those that maximize interest and safety and minimize danger. The hitchhiking model was discussed in terms of hominid sociability and the dependence of individual survival upon group cohesion and cooperation.
Sintering stress of homogeneous and heterogeneous powder compacts

Abstract The thermodynamic meaning of the sintering stress is considered for some simple 2-dimensional porous bodies. The sintering stress acts as an effective mean grainboundary stress and can thus be meaningfully combined with applied stresses. The sintering stress can, in general, not be described in rigorous thermodynamic terms, especially for heterogeneous compacts. Simplifications do allow, however, to assess the effects of some microstructural heterogeneities, including the presence of large pores or of dispersed second phases, on the sintering stress.
The Prevalence and Diagnostic Utility of Endoscopic Features of Eosinophilic Esophagitis: A Meta-analysis

Background & Aims Endoscopic findings such as esophageal rings, strictures, narrow-caliber esophagus, linear furrows, white plaques, and pallor or decreased vasculature might indicate the presence of eosinophilic esophagitis (EoE). We aimed to determine the prevalence and diagnostic utility of endoscopic features of EoE. Methods We conducted a systematic review and meta-analysis. PubMed, EMBASE, and gastrointestinal meeting abstracts were searched to identify studies that included more than 10 patients with EoE and reported endoscopic findings. Pooled prevalence, sensitivity, specificity, and predictive values were calculated using random- and mixed-effects models. Results The search yielded 100 articles and abstracts on 4678 patients with EoE and 2742 without (controls). In subjects with EoE, the overall pooled prevalence was as follows: esophageal rings, 44%; strictures, 21%; narrow-caliber esophagus, 9%; linear furrows, 48%; white plaques, 27%; and pallor/decreased vasculature, 41%. Substantial heterogeneity existed among studies. Results from endoscopy examinations were normal in 17% of patients, but this number decreased to 7% when the analysis was limited to prospective studies ( P Conclusions There is heterogeneity among studies in the reported prevalence of endoscopic findings in patients with EoE, but in prospective studies at least 1 abnormality was detected by endoscopy in 93% of patients. The operating characteristics of endoscopic findings alone are inadequate for diagnosis of EoE. Esophageal biopsy specimens should be obtained from all patients with clinical features of EoE, regardless of the endoscopic appearance of the esophagus.
The family car as a “vehicle” for children's use of distant time referents

Abstract The conversations of nine preschool-aged children (C.A. 4:0–5:2) were tape-recorded as they interacted with teachers and with peers at preschool, as they traveled home from school with their parent in the family car, and as they engaged in routine home activities. The speech samples were coded to identify the time referents the children used in their topics of conversation in the three settings. The study sought to explore suggestions that young children, although generally context-bound in their talk at home and school, are capable of decontextualized talk when settings and conversational partners are familiar and supportive, and when contexts are transitional and prompt talk about other than the here-and-now . Significant differences were found in the children's use of present, past and future time referents in the three settings. Overall, the children spoke most often about the here-and-now, making frequent references to the present activities or to people in each setting. References to past and future events, however, were significantly more frequent in the car setting than in the home or school talk. Most references to the past occurred during the first 5 min of travel and were often prompted by the presence of a project remnant in the car or parents' questions or comments. References to future events occurred more frequently during the latter portion of the car trip. Differences in the children's proportional use of fantasy time referents were not significant. Possible implications for teachers and parents are discussed along with suggestions for future research.
Paleoenvironmental distribution of trace fossils in the catskill deltaic complex, New York State

Abstract The Devonian Tully clastic equivalents and associated rocks of east-central New York State were deposited in fluvial to offshore environments associated with the Catskill delta. These depositional environments have been well defined by Johnson and Johnson and Friedman. The compositional and textural immaturity of the sandstones (immature to submature graywacke) and nearly ubiquitous micro-cross-lamination indicate that rate of sediment supply exceeded rate of reworking. Four of the ichnofossils, including Arenicolites (“small form”), ? Teichichnus, Spirophyton , and large vertically oriented burrow-like structures of probable biological origin are found in narrow paleoenvironmental ranges, within alluvial, tidal, and nearshore facies. However, the other eleven trace fossils, including the most abundant types [ Arenicolites (“large form”), arthropod traces ( Diplichnites, Cruziana, ?Isopodichnus, Rusophycus), Bifungites, ?Chondrites, Skolithos (2 types), Zoophycos , large primarily intrastratally-produced burrows, and simple surficial trails ] occur in rocks deposited under diverse environmental conditions. Their distribution is not clearly related to environment or substrate texture. Factors contributing to the broad lateral distribution of most of the biogenic structures include: (1) the continual influx of sediment from the east, which may have excluded some forms and inhibited the development of stable, environmentally distinct ichnocoenoses, and (2) gradual changes in optimal behavioral patterns resulting from environmental transitions occurring over large geographic distances. The gradational nature of these changes may have exaggerated the broad environmental ranges of the trace-producing animals.
Water chemistry and fish community responses to episodic stream acidification in Pennsylvania, USA.

Five streams were studied on the Northern Appalachian Plateau of Pennsylvania from October 1988 through June 1989 to determine chemical changes that occur during episodic storm run-off and the responses of fish to these events. These second-order streams flowed through undisturbed, wooded, sandstone bedrock catchments with surface areas ranging from 500 to 1000 hectares. Median pH of precipitations was about 4·2, and among streams it ranged from 5·0 to 6·2. During storm events, pH declined by as much as 1·2 units and peak concentrations of total monomeric Al ranged from <0·01 to 0·75 mg litre−1. Organically bound A1 was generally a minor component of total monomeric A1. Wild brook trout (Salvelinus fontinalis) were found in all streams, although only a remnant population existed in the most acidic stream. Sculpins (Cottus bairdi or C. cognatus) were collected only in the two streams with the least severe episodes. Mortality of brook trout and sculpins in in situ bioassays ranged from 0 to about 80% among streams during acidic episodes and was positively related to concentrations of total dissolved Al. Radio-tagged brook trout moved downstream during episodes when Al reached toxic concentrations. Some displaced trout were found near groundwater seeps, where pH was higher and dissolved Al was lower than in the main channel.
Potential climatic effects of cirrus contrails for the subarctic setting of Fairbanks, Alaska

Continuous all-sky camera images supported by direct visual observations of jet contrails have been carried out in Fairbanks since March 2000. These data together with FAA information of all commercial flights and the twice-daily radiosonde data, give the meteorological conditions at flight level under which contrails are formed. If we correct for daylight and clear sky conditions, which make contrail observations possible, winter has the maximum and summer the minimum in the occurrence of contrails. This is a result to be expected, as the layer in which contrails can form has in winter nearly twice the thickness when compared to summer. In November 2002, a radiation station was added to the observations. For a contrail in the path between the sun and the observation point, we found a strong decrease in the direct beam radiation; this loss was in part compensated by increased diffuse radiation. The combined effect leads to a reduction in global radiation. However, the back radiation of the atmosphere in the infrared region of the spectrum increased somewhat. Altogether, this affects the net radiation negatively in the summer, but positively in the winter. Comparing the observed temperature conditions of clear days with those of high-level cloud cover, we found for 8 months of the year a higher temperature for days with clouds. For the other four months, May through August, clear days were warmer. On the average of the year, days with high-level cloudiness were warmer than clear days as well as days with low-level overcast. High-level cloudiness has increased in Alaska over the last decades. This increase in cloudiness was more pronounced under the much-traveled flight corridor from Anchorage to Europe than for more remote areas of Alaska. Further, we found a temperature increase for the same time period, which was most pronounced in winter, followed by spring, a result consistent of the expectations of increased high-level cloudiness.
PROOF WITHOUT WORDS : DOUBLE ANGLE FORMULAS

(1998). Proof Without Words: Double Angle Formulas. Mathematics Magazine: Vol. 71, No. 5, pp. 385-385.
Fire safety in the operating room.

Purpose of reviewElimination of flammable anesthetic gases has had little effect on operating-room fires except to change their etiology. Electrocautery and lasers, in an oxygen-enriched environment, can ignite even the most fire-resistant materials, including the patient, and the fire triad possibi
Developmental expression of trehalase: role of transcriptional activation.

Abstract The third postnatal week of mouse development is characterized by dramatic changes of gene expression in the small intestine. Although these changes are often assumed to reflect regulation at the level of transcription, to date there have been no direct investigations of this. In the current study we have used trehalase as a marker of intestinal maturation. Highly sensitive reverse transcriptase–polymerase chain reaction methods were developed for semi-quantitative analysis of both initial and mature transcripts, i.e., hnRNA and mRNA. Jejunums collected during normal development (specifically from postnatal days 8–21) showed parallel increases in the levels of trehalase hnRNA and mRNA. Likewise, when precocious gut maturation was elicited by dexamethasone administration on days 8–10, both initial and mature trehalase transcripts were significantly increased, although with a relatively slow time course. We conclude that both normal and glucocorticoid-induced maturation of trehalase expression reflect transcriptional activation. However, the slow time course of the glucocorticoid effect suggests that trehalase may not be a primary response gene.
A teleological view of sepsis

1 am grateful to the Society for the privilege and honor of presenting this lecture. It is appropriate that this lecture take place in Greece, where I have so many friends. I would also like to acknowledge the presence as principals in this Society of many talented people in whose career I may have had a small part, providing some of the training. There arc few pleasures in academics that are greater than seeing talented people, with whom you have come in contact and may have influenced in some small way. succeed. These people are among your officers and many are in this room. I am delighted in their success and grateful for their friendship. This work has also been carried out in conjunction with two people with whom many of you are familiar: Dr. Per-Olof Hasselgran, a member of this Society; and Dr. Howard James, who has collaborated with many of you. In addition, I have had the privilege of working in my laboratory with :I number of associates of Dr. Hasselgren: Dr. Peter Pedersen, Dr. Ulf Anger&, and Dr. Marianne Hall-Anger& some faculty of the College of Medicine at Cincinnati, such as Dr. Steve Bjornson, Dr. Hasselgren and Dr. James; a number of residents, including Dr. Dan Benson, Dr. Harry Sax, Dr. Dan von Allmen, and Dr. Brad Warner; and, happily, a second-generation fellow, Dr. Oded Zamir, that is, a resident of one of my former fellows, Dr. Herbert Freund. It is my purpose in this lecture to bring you an overview of a problem that we have struggled with for the past 15 years, and that is the nutritional support of patients with established sepsis. It is a problem which, for a surgeon, remains a major limitation in the therapy of patients. The work that I shall refer to is largely from my own laboratory, although I will refer to the work of others. In a rapidly expanding field, I am aware of a great deal of other work which I will not refer to. It is not my purpose to slight this excellent work, but in trying to develop a theme one chooses those researches which are consistent with that theme.
Late Mesozoic Evolution of the Western Pacific Ocean

A set of east-trending magnetic anomalies located in the western equatorial Pacific Ocean near the Phoenix Islands is Early Cretaceous in age. The use of magnetic reversal model studies shows that this lineated anomaly pattern correlates with one east of Japan that trends east, and with one west of Hawaii that trends northwest. These patterns were formed in their present relative positions, but about 40° (4,500 km) south of their present geographic locations. The configuration of these three contemporaneous sets of magnetic anomalies implies that the Late Mesozoic tectonic pattern consisted of five spreading centers joined at two triple points. In this interpretation, the oldest part of the Pacific Ocean lies just east of the Mariana Trench and is Early Jurassic in age. This Mesozoic system evolved into the Cenozoic spreading pattern recorded in the eastern Pacific Ocean. The details of this transition are open to speculation because it occurred during a period in the Late Cretaceous that lacked magnetic reversals. We propose a model that suggests the northern triple point jumped southeast about 2,000 km at 100 m.y. B.P., and that the Emperor Trough was a transform fault of large offset during the Late Cretaceous. The southern triple point migrated rapidly toward the south-southeast, approximately parallel to the Eltanin Fracture Zone–Louisville Ridge complex that we extend o t the westernmost of the Phoenix lineation fracture zones.
The Geography of Need: Identifying Human Service Needs in Rural America

Given the recent economic crisis and the accompanying funding cuts across social service programs, it is helpful to observe the geographic distribution of demographic characteristics and economic conditions that together create a human service needs profile. The authors provide a conceptual framework for a systematic analysis of county characteristics and demonstrate that rural areas of America have higher levels of needs and more complex needs than do metropolitan areas. This suggests that human service strategies that are successful in metropolitan areas may not translate well to nonmetropolitan areas.
Platelet-derived growth factor-D promotes fibrogenesis of cardiac fibroblasts

Platelet-derived growth factor (PDGF)-D is a newly recognized member of the PDGF family with its role just now being understood. Our previous study shows that PDGF-D and its receptors (PDGFR-β) are...
Power calculations for familial aggregation studies

Family studies are frequently undertaken as the first step in the search for genetic determinants of disease. Significant familial aggregation of disease is suggestive of a genetic etiology for the disease, and may lead to more focused genetic analyses. Many methods have been proposed in the literature for the analysis of family studies. One model that is appealing for its simplicity of computation and the conditional interpretation of its parameters is the quadratic exponential model (e.g., Zhao and Prentice [1990] Biometrika 77:642-648; Betensky and Whittemore [1996] Appl. Stat. 45:422-429; Hudson et al. [2001a] Am. J. Epidemiol. 153:500-514). However, a limiting factor in its application, as well as that of the other proposed methods, is that power and sample size calculations have not been derived. These calculations are essential for investigators who are designing family studies. Here we derive analytic approximations for power for testing for familial aggregation, for both randomly sampled and nonrandomly sampled families. We also present simulation studies of power for both single- and two-disease cases, both under random and nonrandom sampling.
Tissue-engineering scaffolds: can we re-engineer mother nature?

The objective of tissue engineering is to apply the foundations and innovations of biology, medicine and engineering to develop viable, 3D substitutes that support, sustain and/or restore the funct...
Influence of training dose on nicotine discrimination in humans

Non-human research indicates that drug discrimination results may depend largely on the specific training conditions, including initial training dose. It has recently been shown that humans can discriminate among different doses of nicotine delivered by nasal spray. In this study, we examined the influence of training dose on subsequent behavioral discrimination of a range of nicotine doses. Male (n=17) and female smokers (n=16) were randomly assigned to “low” (10 µg/kg) versus “high” (30 µg/kg) nicotine training dose groups and trained reliably to discriminate this dose from placebo (0) on day 1 (≥80% correct identification). All but six subjects (four in low, two in high) learned this discrimination and continued on to day 2, in which both groups received 0, 5, 10, 20, and 30 µg/kg in ascending order (30 min between dosings) and were tested for generalization with their training dose using quantal and quantitative behavioral discrimination tasks. Subjective responses via traditional self-report measures were also assessed. Nicotine-appropriate responding on day 2 was significantly greater in low- versus high-dose groups, especially at 5 µg/kg. However, this difference due to training dose was seen more in women than in men. Discrimination behavior was associated with subjective effects of head rush in males, and with head rush and decline in urge to smoke in females. These results show that discriminative stimulus effects of nicotine are not fixed properties of the drug, but can be influenced by training conditions, and that effects associated with this discrimination may differ between men and women.
Effects of type I/type II interferons and transforming growth factor‐β on B‐cell differentiation and proliferation. Definition of costimulation and cytokine requirements for immunoglobulin synthesis and expression

In this report, we sought to determine the role of selected type I interferons [interferon-alpha (IFN-alpha) and interferon-tau (IFN-tau)], IFN-gamma and transforming growth factor-beta (TGF-beta) in the regulation of bovine antibody responses. B cells were stimulated via CD40 in the presence or absence of B-cell receptor (BCR) cross-linking. IFN-alpha enhanced IgM, IgG2 and IgA responses but did not enhance IgG1 responses. BCR signalling alone was more effective at inducing IgG2 responses with IFN-alpha than dual cross-linking with CD40. Recombinant ovine IFN-tau was less effective at inducing IgG2 responses when compared with IFN-alpha, though IgA responses were similar in magnitude following BCR cross-linking. At higher concentrations, IFN-tau enhanced IgA responses greater than twofold over the levels observed with IFN-alpha. Previous studies have shown that addition of IFN-gamma to BCR or pokeweed mitogen-activated bovine B cells stimulates IgG2 production. However, following CD40 stimulation alone, IFN-gamma was relatively ineffective at stimulating high-rate synthesis of any non-IgM isotype. Dual cross-linking via CD40 and the BCR resulted in decreased synthesis of IgM with a concomitant increase in IgA and similar levels of IgG2 production to those obtained via the BCR alone. We also assessed the effects of endogenous and exogenous TGF-beta on immunoglobulin synthesis by bovine B cells. Exogenous TGF-beta stimulates both IgG2 and IgA production following CD40 and BCR cross-linking in the presence of IL-2. Blocking endogenous TGF-beta did not inhibit the up-regulation of IgG2 or IgA by interferons.
Baryon Interactions in SU(4)

Some properties of baryon interactions in SU(4) symmetry are calculated. These include meson-baryon couplings and various electromagnetic properties of baryons, e.g., magnetic moments, electromagnetic mass differences, and electromagnetic transitions via single-photon emission. Baryons with ${J}^{P}={\frac{1}{2}}^{+}$ and ${J}^{P}={\frac{3}{2}}^{+}$ are considered.
Interaction of cyanobacteria and sulfate-reducing bacteria in subsurface black-layer formation in high-sand content golf greens

Abstract Two Oscillotoria spp and a Nostoc sp., and a culture including Desulfovibrio species, were isolated from the surface and subsurface of high-sand content golf greens which contained subsurface black globules and layers often associated with the death of turf. These isolates and a pure culture of D. desulfurleans were grown for 12 weeks on calcareous sand columns treated with nutrient salts alone or in combination with CaCO 3 , gypsum, sulfur, chelated iron, or chelated iron + S. The Oscillatoria spp slowed water flow in response to most treatments and prevented water now through the sand after 12 weeks in response to S, chelated iron, and chelated iron + S. Nostoc slowed water flow in response to all treatments, and sulfate-reducing bacteria slowed water flow slightly in response to chelated iron. None of the cyanobacteria or sulfate-reducing bacteria isolates alone developed any blackening of the sand columns. Only sand columns on which any of the cyanobacteria isolates were grown for 12 weeks and then infested with either of the sulfate-reducing bacteria isolates developed varying degrees of blackening in the subsequent 12 weeks. Blackening was most intense in response to S, chelated iron, and chelated iron + S. It was concluded that a natural interaction exists between the cyanobacteria and sulfate-reducing bacteria that produces black subsurface globules and layers in high-sand content golf greens, and that the interaction is stimulated by the management practices applied to these greens.
Risk Management for Existing Energy Facilities: A Global Approach to Numerical Safety Goals

This paper presents a structured set of numerical safety goals for risk management of existing energy facilities. The rationale behind these safety goals is based on principles of equity and economic efficiency. Some of the issues involved when using probabilistic risk analyses results for safety decisions are discussed. A brief review of existing safety targets and [open quotes]floating numbers[close quotes] is presented, and a set of safety goals for industrial risk management is proposed. Relaxation of these standards for existing facilities, the relevance of the lifetime of the plant, the treatment of uncertainties, and problems of failure dependencies are discussed briefly. 17 refs., 1 fig.