cssi/SciSciGPT-SciSciNet huggingface dataset:
The Blood-Brain Barrier in Health and Chronic Neurodegenerative Disorders

The blood-brain barrier (BBB) is a highly specialized brain endothelial structure of the fully differentiated neurovascular system. In concert with pericytes, astrocytes, and microglia, the BBB separates components of the circulating blood from neurons. Moreover, the BBB maintains the chemical composition of the neuronal "milieu," which is required for proper functioning of neuronal circuits, synaptic transmission, synaptic remodeling, angiogenesis, and neurogenesis in the adult brain. BBB breakdown, due to disruption of the tight junctions, altered transport of molecules between blood and brain and brain and blood, aberrant angiogenesis, vessel regression, brain hypoperfusion, and inflammatory responses, may initiate and/or contribute to a "vicious circle" of the disease process, resulting in progressive synaptic and neuronal dysfunction and loss in disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, and others. These findings support developments of new therapeutic approaches for chronic neurodegenerative disorders directed at the BBB and other nonneuronal cells of the neurovascular unit.
A risk evaluation of the maximum entropy correlation coefficients

For random samples from a bivariate normal distribution with correlation coefficient ϱ, maximum entropy (ME) correlations are compared to sample correlations. ME correlations exhibit greater bias but for βϱβ< 0.6 have smaller root mean squared error (RMSE), particularly for a small sample. For 0.6 <βϱβ< 0.8, sample correlations have only slightly smaller RMSE than ME correlations.
The relationship between acetylcholine- and histamine-induced constriction of large airways in normal subjects and subjects with asthma: A possible role for postreceptor mechanisms

Whether in man histamine (H) and acetylcholine (ACH) airway responses are interrelated is controversial. With the use of quantitative nebulization and specific airway conductance (Gaw/VL), we recorded noninvasive pharmacologic tests of H- and ACH-induced bronchoconstriction in 11 normal subjects (N) and nine subjects with asthma (AST) with and without pretreatment of 0.75 mg (A0.75) and 1.50 mg (A1.50) of inhaled atropine. Provocation dose 40 (PD40) for H or ACH were different in N (0.8 X 10(-2) mol/L and 2.9 X 10(-2) mol/L, respectively) and AST (5.0 X 10(-3) mol/L and 7.8 X 10(-3) mol/L) but linearly related. The ratio PD40-ACH/PD40-H was comparable in N and AST and similar to the ratio ACH sensitivity/H sensitivity found in vitro for large airways. The slopes of log dose-response curves (SLDRC) to H and SLDRC to ACH were of similar magnitude both in N and AST and linearly related; however, for either agonist, bronchial sensitivity (PD40) and reactivity (SLDRC) failed to correlate. After A0.75, the dose ratios (DR) of H and ACH were large, with substantial intersubject variability, and similar in N (4.32 and 9.54, respectively) and AST (5.97 and 5.64). Although numerically comparable, DR of H and DR of ACH were unrelated. After A1.50, DR of H remained unchanged (4.53 in N and 5.44 in AST), but DR of ACH further increased (17.37 in N and 8.13 in AST). Pretreatment with A0.75 respected the linear relationship of PD40-H versus PD40-ACH but blurred that of reactivity to these agonists. After A0.75 or A1.50, delta Gaw/VL was similar in N and AST. Except for PD40, none of the tests recorded could distinguish AST from N. In conclusion, H-induced bronchoconstriction is substantially but not exclusively mediated via ACH pathway. We hypothesize that H and ACH responses anastomose within the cholinergic pathway at a sensitivity and a reactivity level; the former level is ostensibly downstream from and unrelated to the latter. In AST, the reactivity to H and ACH, the bronchodilating, anti-histaminic (DR of H) and antimuscarinic (DR of ACH) effects of atropine are normal and so is ostensibly the anastomosis between H and ACH reactivity levels. The level of H and ACH sensitivity distinguishes AST from N. ACH-sensitivity site may be located at the H- greater than ACH anastomosis.
Polypeptides synthesized in herpes simplex virus type 2-infected HEp-2 cells

Abstract The proteins induced by herpes simplex virus type 2 in infected HEp-2 cells were studied by high-resolution polyacrylamide slab-gel electrophoresis. A total of 51 infected cell-specific polypeptides (ICSP) were detected, accounting for three-fourths of the coding capacity of the virus. The induced polypeptides were allocated to three groups based on their time of synthesis in the virus growth cycle. Cycloheximide treatment of infected cells during the early stage of virus growth was found to cause irreversible inhibition of protein synthesis. Herpes simplex virus type 2 polypeptides which underwent considerable posttranslational modification were detected.
Addition of lysines to the 50/20 kDa junction of myosin strengthens weak binding to actin without affecting the maximum ATPase activity.

Much interest has centered on two surface loops in the motor domain to explain the differences in enzymatic and mechanical properties of myosin isoforms. We showed that two invariant lysines at the C-terminal end of loop 2, which is part of the actin-binding interface, are required to obtain actin activation [Joel et al. (2001) J. Biol. Chem. 276, 2998-3003]. Here we investigate the effects of increasing positive charge in the variable portion of loop 2 of smooth muscle heavy meromyosin (smHMM). Increasing the net positive charge by +4 increased the affinity for actin in the presence and absence of ATP. The K m for actin-activated ATPase activity decreased 15-fold, but V m a x was unchanged, showing that "weak binding" of myosin for actin can be significantly strengthened without increasing the rate-limiting step for V m a x . The mutant HMM had slower rates of in vitro motility and ADP release compared to WT HMM. ADP release and motility, which were both salt-dependent, correlated linearly with each other. Loop 2 thus plays a major role in setting the affinity for actin but also affects ADP release and motility. Because the actin- and nucleotide-binding regions communicate, mutations to one region can impact multiple facets of myosin's mechanical and enzymatic properties.
Patient satisfaction with treatment decisions for clinically localized prostate carcinoma. Results from the Prostate Cancer Outcomes Study.

BACKGROUND Men with early-stage prostate carcinoma can choose aggressive treatment or conservative management. The authors used data from a population-based cohort of men with clinically localized prostate carcinoma to describe satisfaction with treatment decisions 24 months after diagnosis and to examine the association of demographic, socioeconomic, and clinical characteristics with treatment satisfaction. METHODS The authors evaluated 2365 men with clinically localized prostate carcinoma, diagnosed between October 1994 and October 1995, in one of six Surveillance, Epidemiology, and End Results tumor registries and who were available for 24 month follow-up. Medical record review and patient-completed surveys provided demographic, socioeconomic, and clinical data and measured treatment satisfaction. Logistic regression analyses were used to identify factors associated with satisfaction. RESULTS Overall, 59.2% of subjects were delighted or very pleased with their treatment selection. The perception of being cancer free (66.4%), maintaining urinary (64.2%) and bowel (60.5%) control and normal erectile function (65.9%), having good general health (71.3%), and preserving social relationships (68.1%) were significantly associated with being satisfied (P < 0.05). Men receiving no active treatment were less satisfied (50.5%, P < 0.001) than actively treated men, and Hispanic men were less satisfied than non-Hispanic white men after undergoing radical prostatectomy (50.1% vs. 58.0%, P = 0.05) or androgen deprivation (29.7% vs. 71.8%, P < 0.02). CONCLUSIONS The majority of men were satisfied with their treatment selection for clinically localized prostate carcinoma. Receiving an active treatment, believing oneself to be free of cancer, avoiding treatment complications, and having good overall health and social support were positively associated with satisfaction. Cancer 2003;97:1653–62. © 2003 American Cancer Society. DOI 10.1002/cncr.11233
Governance and Collaboration: An Evolutionary Study of Two Mental Health Networks

As examples of a state of agents, this paper will present a comparative analysis of the evolution of two community mental health networks that both have similar contracts from the State of Arizona and operate under the same set of rules. One of these is governed by a for-profit firm that both produces services directly and buys them from a network of nonprofit agencies. The other is governed by a community based nonprofit that contracts with four separate nonprofit networks to offer services. These networks are analyzed, using social network analysis, at the beginning of the system and four years later. The mature network is compared to the new network. The for-profit governed system is compared to the nonprofit governed system. The paper discusses the evolution of structure over time and a limited comparison of the networks in terms of which produced higher quality outcomes.
Snake, spider, and scorpion envenomation in North America.

1. G. Randall Bond, MD* 1. 2. *Associate Professor, Departments of Emergency Medicine and Pediatrics, Medical Director, Blue Ridge Poison Center, University of Virginia, Charlottesville, VA. After completing this article, readers should be able to: 1. Describe which measures for snakebite are harmful and should be avoided. 2. List the signs, symptoms, and findings that indicate a more significant envenomation and the need for intervention with antivenin. 3. Explain when a fasciotomy should be performed and when surgical consultation is necessary. 4. Describe the cornerstone of treatment for black widow spider envenomation. 5. Describe the treatment of brown recluse spider envenomation. In North America, approximately 2,500 children experience a poisonous snakebite each year. More than 95% of these are from pit vipers (family Crotalidae ), including rattlesnakes, moccasins, cotton mouths, and copperheads. Because children have smaller limbs and less subcutaneous tissue and they receive a larger dose of venom per kilogram, their clinical course often is more severe than that of adults. Fortunately, death is rare. ### SIGNS AND SYMPTOMS Pit vipers have no legs and no teeth for mastication. Their venom contains a variety of toxins to halt and kill their prey quickly and to begin the process of digestion from within. Specific components cause direct tissue injury, capillary leakage, coagulopathy, and neurotoxicity. Bites usually cause significant pain from the moment of envenomation. Swelling occurs at the site and progresses at a variable rate, depending on the amount and potency of the venom injected. Local areas may become extremely swollen and tense, and ecchymosis may be noted. Vascular compromise can occur, particularly of the digits. In time, fluid-filled or hemorrhagic bullae may form at the site of the bite, and eventually an area of necrosis may become apparent. Frequently, the first sign of systemic envenomation is tender regional lymph nodes. Other signs include nausea, a metallic taste in the mouth, muscle fasciculations, bleeding from intravenous puncture sites, and less commonly, hypotension and shock. Ptosis and weakness are common following envenomation by some subspecies of the …
Major depression with psychosis after resection of a giant middle fossa hemangiopericytoma.

Abstract Background Postoperative onset of acute major depression in a patient with no previous history of psychiatric disorder is highly unexpected after skull base surgery. Case Description A 38-year-old woman with no previous physical or mental illness presented with a 3-month history of left ear pain, short-term memory disturbance, and motor dysphasia. Magnetic resonance imaging revealed a large extraaxial tumor in the left middle fossa. Left temporal craniotomy was performed, achieving complete tumor resection. The patient showed signs of confusion, disorientation, and severe depression 3 days after the surgery. She developed insomnia and auditory hallucinations along with expressed suicidal ideation, then deteriorated rapidly, necessitating a transfer to a psychiatric unit. In spite of the intensive treatment with antidepressive and antipsychotic medications, she continued to have prolonged psychotic symptoms and depression for several months after surgery. Conclusion Although the incidence is rare, psychiatric complications should be anticipated in patients undergoing resection of a large skull base tumor affecting the temporal lobe. The exact mechanism in this process is not clear; however, it is important to clinically differentiate treatable etiologies such as steroid-induced psychosis and postoperative delirium.
Theological Statements, Phenomenalistic Language and Confirmation

In a recent paper Michael Tooley has argued that theological statements can be confirmed relative to a phenomenalistic observational language given a certain construal of confirmation. Consequently, he maintains that the verificationist challenge to theological statements, namely that in order to be significant they must be confirmable, can be answered. In this paper I will show that Tooley's argument has serious problems.
The farmland conversion process in a polynucleated metropolis

Abstract The conversion of farmland to urban land uses is analyzed for a study area on the fringe of Chicago (USA) for the period between 1975 and 1990. Several geographic information system databases are developed to examine the amount and quality of farmland being lost to urban development. The results show that “edge cities” are redefining the landscapes of the urban fringe where low-density residential uses are replacing prime farmland at a rapid rate. A national-level database is used to compare the Chicago area results with other large urban areas of the USA's Midwest. Most large cities of the Midwest reveal a similar pattern of development replacing prime farmland on the urban fringe.
In vitro apolipoprotein B mRNA editing: identification of a 27S editing complex.

Abstract Specific apolipoprotein B (apoB) mRNA editing can be performed in vitro on apoB RNA substrates. Native gels and glycerol gradient sedimentation have been used to determine the physical properties of the in vitro editing activity in rat liver cytosolic S100 extracts. ApoB RNA substrates were progressively assembled as 27S complexes for 3 hr with similar kinetics as seen for the accumulation of edited RNA. Assembly was not observed on RNAs from apoB deletion constructs that did not support editing. The 27S complex contained both edited and unedited RNA sequences. Inhibition of 27S complex assembly by vanadyl-ribonucleoside complexes was accompanied by inhibition of editing. Based on these data, we propose that the 27S complex is the in vitro "editosome," A "mooring sequence" model for RNA recognition and editosome assembly has been proposed involving RNA sequences flanking the edited nucleotide.
Plant analysis of trace elements by X‐Ray‐

Abstract Energy dispersive X‐ray fluorescence (EDXRF) has been shown to be an effective technique for multielement analyses of plant tissues. Elements can be assayed above the atomic number of Na (11) including S, Cl, Br, and trace elements, except B. Once parameters and programs critical for quantitative analyses have been developed, analysis is relatively simple. Overall optimal pellet weights of 500 mg (32 mm diameter) and 100 mg (13 diameter) were chosen. It was found that weights could vary ± 25% without significant change in intensities. Samples ground to 1 mm, 20‐mesh, and 80‐mesh did not show significant intensity differences. When 1 g of boric acid was used to back pellets, intensities for light elements (Mg, Al, Si, P, S) were increased, but for higher atomic number elements intensities decreased from 60% to less than 20% those of non‐backed pellets. Minimum detection limits (MDL) for various elements were (in ug/g 135 Mg, 32 Al, 28 Si, 25 P, 19 S, 9.3 Cl, 40 K, 30 Ca, 1.9 Mn, 1.4 Fe, 1.1 Cu, 1....
Recognition of Gilmore-Gomory traveling salesman problem

Abstract The best known special case of the traveling salesman problem that is well solved is that due to Gilmore and Gomory. It is a problem of scheduling a heat treatment furnace. In this paper we give a polynomial algorithm for detecting whether or not a given traveling salesman problem is an instance of their problem; we also compute the parameters necessary to apply their algorithm. Thus all such problems can not only be solved in polynomial time but also recognized in polynomial time.
Oral glycoprotein IIb/IIIa antagonists in coronary artery disease

Despite the efficacy of intravenous glycoprotein IIb/IIIa inhibition in patients undergoing percutaneous coronary intervention and those presenting with acute coronary syndromes, the application of oral glycoprotein IIb/IIIa inhibition to the chronic management of coronary artery disease has not met with the same success. To explain these results, factors related to dosing, and inadequate inhibition or activation of platelet pro-coagulant activity have been recently suggested. However, although the disparity between intravenous and oral glycoprotein IIb/IIIa experience remains largely enigmatic, the discordant effect on ischemic endpoints observed within the phase III oral glycoprotein IIb/IIIa inhibitor trials potentially implicates a mechanism unrelated to platelet function.
Epigenetic Therapy in Breast Cancer

Breast carcinogenesis is a multistep process involving both genetic and epigenetic changes. Epigenetics is defined as reversible changes in gene expression, not accompanied by alteration in gene sequence. DNA methylation, histone modification, and nucleosome remodeling are the major epigenetic changes that are dysregulated in breast cancer. Several genes involved in proliferation, anti-apoptosis, invasion, and metastasis have been shown to undergo epigenetic changes in breast cancer. Because epigenetic changes are potentially reversible processes, much effort has been directed toward understanding this mechanism with the goal of finding effective therapies that target these changes. Both demethylating agents and the histone deacetylase inhibitors (HDACi) are under investigation as single agents or in combination with other systemic therapies in the treatment of breast cancer. In this review, we discuss the role of epigenetic regulation in breast cancer, in particular focusing on the clinical trials using therapies that modulate epigenetic mechanisms.
Determination of balloon gas mass and revised estimates of drag and virtual mass coefficients

In support of the NASA Balloon Program, small-scale balloons were flown with varying lifting gas and total system mass. Instrument packages were developed to measure and record acceleration and temperature data during these tests. Top fitting and instrument payload accelerations were measured from launch to steady state ascent and through ballast drop transients. The development of the small lightweight self-powered Stowaway Special instrument packages is discussed along with mathematical models developed to determine gas mass, drag and virtual mass coefficients.
A functional link between FOXA1 and breast cancer SNPs

Genome-wide association studies have revealed a multitude of breast cancer-associated SNPs. The majority of these SNPs are located in noncoding regions of the genome. Yet how they contribute to breast cancer development is unknown. Recently, a groundbreaking study by the Lupien group has shown that risk-associated SNPs of breast cancer are enriched for FOXA1 binding sites, which influences the function of this transcription factor.
An abridged technique to diagnose spectrophotometric errors

The effect on colorimetric accuracy of spectrophotometric errors (±0.5 and ±1% reference white, ±0.25 and ±0.5% reference black, and ±0.5 and ±1 nm wavelength) was simulated for the BCRA Series II tile set by using previously investigated models for these errors. ΔE*94 color differences of up to 5.2 could result. Because the errors are linearly related to CIELAB differences for each tile, a technique was derived that enabled ΔL*, Δa*, and Δb* coordinates between a calibrated tile and its measured value to be transformed into estimates of reference white, reference black, and wavelength error. The cyan tile was identified as the most effective tile for this technique. “Universal” equations are included for 45/Normal and Normal/Total geometries traceable to the National Institute of Standards and Technology (NIST), and Normal/45, Normal/Total, and Normal/Diffuse geometries traceable to the National Physical Laboratory (NPL). Measuring the cyan tile on a regular basis and transforming its colorimetric coordinates into spectrophotometric error metrics provides a useful method to validate the accuracy and reproducibility of a color-measurement instrument. © 1997 John Wiley & Sons, Inc. Col Res Appl, 22, 51–60, 1997.
Chapter 39 The Edwardsburg Formation and related rocks, Windermere Supergroup, central Idaho, USA

Abstract In central Idaho, Neoproterozoic stratified rocks are engulfed by the Late Cretaceous Idaho batholith and by Eocene volcanic and plutonic rocks of the Challis event. Studied sections in the Gospel Peaks and Big Creek areas of west-central Idaho are in roof pendants of the Idaho batholith. A drill core section studied from near Challis, east-central Idaho, lies beneath the Challis Volcanic Group and is not exposed at the surface. Metamorphic and deformational overprinting, as well as widespread dismembering by the younger igneous rocks, conceals many primary details. Despite this, these rocks provide important links for regional correlations and have produced critical geochronological data for two Neoproterozoic glacial periods in the North American Cordillera. At the base of the section, the more than 700-m-thick Edwardsburg Formation (Fm.) contains interlayered diamictite and volcanic rocks. There are two diamictite-bearing members in the Edwardsburg Fm. that are closely related in time. Each of the diamictites is associated with intermediate composition tuff or flow rocks and the diamictites are separated by mafic volcanic rocks. SHRIMP U–Pb dating indicates that the lower diamictite is about 685±7 Ma, whereas the upper diamictite is 684±4 Ma. The diamictite units are part of a cycle of rocks from coarse clastic, to fine clastic, to carbonate rocks that, by correlation to better preserved sections, are thought to record an older Cryogenian glacial to interglacial period in the northern US Cordillera. The more than 75-m-thick diamictite of Daugherty Gulch is dated at 664±6 Ma. This unit is preserved only in drill core and the palaeoenvironmental interpretation and local stratigraphic relations are non-unique. Thus, the date for this diamictite may provide a date for a newly recognized glaciogenic horizon or may be a minimum age for the diamictite in the Edwardsburg Fm. The c . 1000-m-thick Moores Lake Fm. is an amphibolite facies diamictite in which glacial features have not been observed. However, it is part of a sedimentary cycle from unsorted siliclastic deposits to mud and carbonate deposits. Using lithostratigraphy and available geochronology, the Moores Lake Fm. is correlated with a younger succession of Cryogenian glaciogenic rocks in southeastern Idaho. Traditional correlations of Neoproterozoic rocks in the Cordillera recognize two levels of Cryogenian diamictites. The Edwardsburg and Moores Lake diamictites along the middle Cordillera fit well into the scenario of two glacial events. Because of the correlations, dates that provide ages for the diamictites in central Idaho (and corroborated in southeastern Idaho, Link & Fanning 2008) could constrain the age of correlated glaciogenic deposits elsewhere in the Cordillera. However, in the absence of dates for the glaciogenic diamictites in Canadian and southern US Cordilleran sections, the correlations are considered possible but uncertain.
Metabolomics, Pathway Regulation, and Pathway Discovery

Metabolomics is a data-based research strategy, the aims of which are to identify biomarker pictures of metabolic systems and metabolic perturbations and to formulate hypotheses to be tested. It involves the assay by mass spectrometry or NMR of many metabolites present in the biological system investigated. In this minireview, we outline studies in which metabolomics led to useful biomarkers of metabolic processes. We also illustrate how the discovery potential of metabolomics is enhanced by associating it with stable isotopic techniques.
Aging young sleep: a test of the phase advance hypothesis of sleep disturbance in the elderly.

SUMMARY With aging, the phase relationship between sleep and body core temperature is altered such that the temperature minimum occurs substantially earlier in the major nocturnal sleep period. The sleep maintenance difficulties that often accompany normal aging are generally assumed to be associated with this age-related change in the phase angle between sleep and temperature. To test this notion, we used timed exposure to bright light to reproduce in healthy young adults a similar phase relationship between temperature and sleep, to determine if such a manipulation would induce the same fragmented nocturnal sleep commonly observed in individuals over 65 years of age. Seven young adults were exposed to morning bright light for 3 consecutive days following a baseline night. Bright light exposure caused a 97 min phase advance of the fitted temperature minimum when compared with baseline. Significant declines in several measures of sleep quality were associated with the phase advance, including wakefulness after initial sleep onset (WASO), sleep efficiency and number of stage changes. Yet, the severity of sleep disturbance exhibited by these subjects did not approach that exhibited by most elderly subjects. The findings suggest that while chronophysiological changes appear to be strongly associated with the tendency to awaken in the early morning, they cannot account entirely for the severity of sleep disturbance frequently observed in older subjects.
Observation and low-energy-electron-diffraction structure analysis of the Ge(111)-(√3 × √3 ) R 30°-Bi system

Surface reconstruction of the submonolayer Bi/Ge(111) system was investigated by low-energy diffraction and Auger-electron spectroscopy. It was found that an ordered (\ensuremath{\surd}3 \ifmmode\times\else\texttimes\fi{} \ensuremath{\surd}3 ) superstructure is formed at \ensuremath{\sim}1/3 monolayer Bi deposition on the \ensuremath{\sim}320 \ifmmode^\circ\else\textdegree\fi{}C surface. The data were analyzed by full dynamical low-energy-electron-diffraction calculations. A quantitative comparison between experiment and calculated I-V spectra suggests that the Bi adatoms are located at the ${\mathit{T}}_{4}$ site 1.324 \AA{} above the first Ge layer. Our results imply that substrate atoms in the first two atomic layers are significantly displaced from their ideal bulk positions. Details of the atomic coordinates are given.
Long-Term Follow-Up After Robotic Thymectomy for Nonthymomatous Myasthenia Gravis

Background Thymectomy is recognized as a significant component in the treatment of myasthenia gravis. However, controversy exists as to the optimal surgical approach. This investigation summarizes our experience performing extended thymectomy using a robotic technique in a large group of patients with significant follow-up. Methods Data collection for patients undergoing robotic thymectomy for nonthymomatous myasthenia gravis over a 6-year period was prospectively performed. Patients were assessed using the Myasthenia Gravis Foundation of America's quantitative disease severity score and the post intervention status classification. Results During the study period, 75 patients underwent thymectomy by this method. Mean preoperative myasthenia gravis severity score was 2.7. Mean operative time was 113 ± 46 minutes. Extubation in the operating room occurred in 73 (98%) patients. Mean intensive care stay and total hospital length of stay were 0.9 and 2.2 days respectively. Mean interval between surgery and return to work (or prethymectomy activities of daily living) was 15 ± 6 days. Significant improvement of myasthenia gravis symptoms occurred in 65 (87%) patients with a mean follow-up of 45 ± 14 months. Conclusions Robotic-assisted thymectomy is a safe and effective technique for patients with symptomatic myasthenia gravis. It allowed an extended thymectomy to be performed without the associated length of stay or recovery period of a transsternal approach while producing comparable rates of symptom improvement.
Function and horizontal transfer of the small terminase subunit of the tailed bacteriophage Sf6 DNA packaging nanomotor

Abstract Bacteriophage Sf6 DNA packaging series initiate at many locations across a 2 kbp region. Our in vivo studies show that Sf6 small terminase subunit (TerS) protein recognizes a specific packaging (pac) site near the center of this region, that this site lies within the portion of the Sf6 gene that encodes the DNA-binding domain of TerS protein, that this domain of the TerS protein is responsible for the imprecision in Sf6 packaging initiation, and that the DNA-binding domain of TerS must be covalently attached to the domain that interacts with the rest of the packaging motor. The TerS DNA-binding domain is self-contained in that it apparently does not interact closely with the rest of the motor and it binds to a recognition site that lies within the DNA that encodes the domain. This arrangement has allowed the horizontal exchange of terS genes among phages to be very successful.
Detoxification of organophosphate nerve agents by immobilized Escherichia coli with surface‐expressed organophosphorus hydrolase

An improved whole-cell technology for detoxifying organophosphate nerve agents was recently developed based on genetically engineered Escherichia coli with organophosphorus hydrolase anchored on the surface. This article reports the immobilization of these novel biocatalysts on nonwoven polypropylene fabric and their applications in detoxifying contaminated wastewaters. The best cell loading (256 mg cell dry weight/g of support or 50 mg cell dry weight/cm2 of support) and subsequent hydrolysis of organophosphate nerve agents were achieved by immobilizing nongrowing cells in a pH 8, 150 mM citrate-phosphate buffer supplemented with 1 mM Co2+ for 48 h via simple adsorption, followed by organophosphate hydrolysis in a pH 8, 50 mM citrate-phosphate buffer supplemented with 0.05 mM Co2+ and 20% methanol at 37°C. In batch operations, the immobilized cells degraded 100% of 0.8 mM paraoxon, a model organophosphate nerve agent, in approximately 100 min, at a specific rate of 0.160 mM min−1 (g cell dry wt)−1. The immobilized cells retained almost 100% activity during the initial six repeated cycles and close to 90% activity even after 12 repeated cycles, extending over a period of 19 days without any nutrient supplementation. In addition to paraoxon, other commonly used organophosphates, such as diazinon, coumaphos, and methylparathion were hydrolyzed efficiently. The cell immobilization technology developed here paves the way for an efficient, simple, and cost-effective method for detoxification of organophosphate nerve agents. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 63: 216–223, 1999.
Repeatability and Reproducibility of Mobile Retroreflectivity Units for Measurement of Pavement Markings

The Florida Department of Transportation has historically used a combination of handheld devices and visual surveys to evaluate the retroreflectivity of pavement markings. However, visual surveys have the inherent limitations of operator bias, while the use of a handheld device is slow and labor intensive and presents safety hazards. Many highway agencies have recognized that a mobile retroreflectivity unit (MRU) may be a safer and more efficient alternative to the handheld retroreflectometers. Because the measurement process relies on the operator-driven instrument, a level of uncertainty is always a concern in evaluating pavement markings with the MRU. This research was aimed at assessing the precision and bias of the MRU while using the handheld retroreflectometer as a reference device. Ten 1.0-mi-long field sites were selected to include various pavement surface types and pavement marking materials (paints and thermoplastics). The results indicated that, when compared with the handheld retroreflectome...
Hyperfine Separation of Ground-State Atomic Hydrogen

The hyperfine separation of hydrogen in its ground state was determined by means of the hydrogen maser. Two masers were operated simultaneously for purposes of tuning, checking internal consistency, and measuring the wall shift. A secondary frequency standard was also used. Corrections were made for the magnetic field offset, secondorder Doppler shift, and the wall shift. (C.E.S.)
Adolescent neurological development and its implications for adolescent substance use prevention.

Recent technological advancements have facilitated the study of adolescent neurological development and its implications for adolescent decision-making and behavior. This article reviews findings from the adolescent neurodevelopment and substance use prevention literatures. It also discusses how findings from these two distinct areas of adolescent development can complement each other and be used to build more developmentally appropriate interventions for preventing adolescent substance use. Specifically, a combination of child-centered and family-based strategies is advocated based on extant neurological and prevention literature. Editors’ strategic implications: Researchers are encouraged to take up the authors’ challenge and study the links between adolescent neurological development/decision making ability and the long term efficacy of comprehensive interventions for preventing adolescent substance use.
Functional Domain Mapping of the Clathrin-associated Adaptor Medium Chains ॖ1 and ॖ2 *

The clathrin-associated adaptors AP-1 and AP-2 are heterotetrameric complexes involved in the recognition of sorting signals present within the cytosolic domain of integral membrane proteins. The medium chains of these complexes, 1 and 2, have been implicated in two types of interaction: assembly with the 1 and 2 chains of the corresponding complexes and recognition of tyrosine-based sorting signals. In this study, we report the results of a structure-function analysis of the 1 and 2 chains aimed at identifying regions of the molecules that are responsible for each of the two interactions. Analyses using the yeast two-hybrid system and proteolytic digestion experiments suggest that 1 and 2 have a bipartite structure, with the amino-terminal one-third (residues 1–145 of 1 and 2) being involved in assembly with the chains and the carboxyl-terminal two-thirds (residues 147–423 of 1 and 164–435 of 2) binding tyrosine-based sorting signals. These observations support a model in which the amino-terminal one-third of 2 is embedded within the core of the AP-2 complex, while the carboxyl-terminal two-thirds of the protein are exposed to the medium, placing this region in a position to interact with tyrosine-based sorting signals.
The Composition and Social-Organization of Mixed-Species Flocks in a Tropical Deciduous Forest in Western Mexico

I recorded the flocking propensity of birds within a tropical deciduous forest in western Mexico during the nonbreeding season, and determined the species composition of57 mixed-species, canopy insectivore flocks. Each of 27 canopy insectivore species present on the study area was observed foraging in mixed-species flocks on at least half of the occasions that it was detected on bird surveys. The proportion of flocks within which a given species was detected could be predicted on the basis of its index of abundance, as determined from independently derived point count data. Therefore, flocks are not comprised of a special subset of canopy insectivores; rather, the composition of flocks appears to be a product of whichever species co-occur within the foraging range of one or more nuclear species. No two canopy insectivore species were negatively associated among flocks, but 40 of 210 possible pairs (19%) were significantly positively associated. Two long-distance migratory species (Nashville Warbler [ Vermivora ruficapilla] and Bluegray Gnatcatcher [Polioptila caerulea]) shared features that characterize nuclear species, thereby constituting one of the first recorded instances where nonresident species play such a role. Five of the more common flocking species were equally likely to have a foraging neighbor nearby (<3 m away), but the identity of that neighbor differed significantly among the five species. Specifically, the identity of close neighbors of the two nuclear species was a random subset of the species available, while the close associates of three attendant species were a nonrandom subset of (mostly) other attendant species. The independent associations among flocks, which characterize most species, and the observation that nuclear species were not close neighbors more than expected for any of three attendant species suggests that foraging enhancement is not the principal benefit that attendant species derive from flocking.
Fluid pressure measurement using bubbles insonified by two frequencies

Abstract The double frequency method, where bubbles rising through a fluid are illuminated simultaneously with a ‘pump’ frequency swept through the resonance frequency range and a megahertz imaging frequency, is used to measure pressure changes in fluids non-invasively. The bubble echo spectrum is centred at the imaging frequency with side bands at separations equal to the pump frequency. If the ambient pressure is changed, the bubbles undergo changes in their sizes. This would alter the resonant frequency of the bubble and hence the peak of the echo at the sum (or difference) frequency. By observing shifts in the frequency of the peak amplitude of the side bands it is shown that fluid pressure changes can be measured accurately.
Resource discovery in federated systems with voluntary sharing

Federated system is a popular paradigm for multiple organizations to collaborate and share resources for common benefits. In practice, however, these organizations are often within different administrative domains and thus demand autonomous resource management, as opposed to blindly exporting their resources for efficient search. To address these challenges, we present a new resource discovery middleware, called ROADS, that can facilitate voluntary sharing. In ROADS, the participants can associate with each other at their own will and dictate the extent of sharing by properly exporting summaries, a condensed representation of their resource records. To enable efficient search, these summaries are aggregated and replicated along an overlay-assisted server hierarchy, and the queries are routed to those servers that are likely to hold the desired resources. Our experimental results show that ROADS provides not only flexible resource sharing for federated systems but also efficient resource discovery, with performance comparable to a centrally managed system.
Origins of Injection-Site Sarcomas in Cats: The Possible Role of Chronic Inflammation—A Review

The etiology of feline injection-site sarcomas remains obscure. Sarcomas and other tumors are known to be associated with viral infections in humans and other animals, including cats. However, the available evidence suggests that this is not the case with feline injection-site sarcomas. These tumors have more in common with sarcomas noted in experimental studies with laboratory animals where foreign materials such as glass, plastics, and metal are the causal agent. Tumors arising with these agents are associated with chronic inflammation at the injection or implantation sites. Similar tumors have been observed, albeit infrequently, at microchip implantation sites, and these also are associated with chronic inflammation. It is suggested that injection-site sarcomas in cats may arise at the administration site as a result of chronic inflammation, possibly provoked by adjuvant materials, with subsequent DNA damage, cellular transformation, and clonal expansion. However, more fundamental research is required to elucidate the mechanisms involved.
The structure of an actin-crosslinking domain from human fimbrin

The structure of the N-terminal actin binding domain of human f imbrin offers the first view of an F-actin crosslinking protein and is representative of the conserved actin binding domain found in the largest family of crosslinking proteins. This domain is composed of two calponin homology domains and allows for the mapping of residues implicated in F-actin binding.
Seismic-attribute identification of brittle and TOC-rich zones within the Eagle Ford Shale, Dimmit County, South Texas

Analysis of 3D poststack seismic attributes can be used to identify areas of high exploration potential within shale resource plays. We integrated seismic attributes and acoustic impedance (AI) with wireline logs to determine total organic carbon (TOC) distribution within the Eagle Ford Shale in South Texas. We computed TOC from wireline logs using the Δ Log R method and then used seismic attributes to predict TOC and deep-resistivity log distribution, and identify brittle zones within the seismic survey. Our results show that high-TOC and high-resistivity zones are laterally more continuous in the south part of the survey. In the north, continuity of these properties is broken by NE–SW-trending faults having throws ranging from about 10 to 100 ft (3–30 m). High resistivity occurs in high-quality-factor (Q) attribute zones. Although the relationship is nonlinear, resistivity and TOC increase as Q increases. That is, both properties increase with increasing bed resistance suggesting increasing carbonate. Two high-resistivity zones, an upper resistive bed and a lower resistive bed, are identified within the Eagle Ford Shale. Additionally, because a strong positive linear relationship exists between AI and Q, Q can be used to identify brittle zones. Compared to other attributes used in identification of brittle zones, Q is faster and cheaper to compute from 3D poststack seismic data. Therefore, Q could serve as a quicker, alternate method of identifying brittle zones within the Eagle Ford Shale.
Bowel obstruction in patients with ovarian carcinoma: Analysis of prognostic factors

A retrospective study was performed in which patients with both bowel obstruction and ovarian carcinoma admitted to the gynecologic oncology service at the Milton S. Hershey Medical Center between July 1, 1980, and June 30, 1987, were examined. Thirty-three patients were identified who fulfilled the inclusion criteria for bowel obstruction that did not occur in the postoperative period. Historical, physical, nutritional, and laboratory variables thought to contribute to patient survival were evaluated by a retrospective chart review. Survival time was not significantly related to presence or absence of tumor at obstruction, type of intervention whether medical or surgical, patient age, or interval from initial diagnosis of ovarian cancer to obstruction. Survival time was found to be significantly related to the prognostic index initially proposed by H. B. Krebs and D. R. Goplerud [Obstet. Gynecol. 61, 327-330 (1983)], P = 0.002. This prognostic index incorporates a multifactorial assessment of patient status including age, nutritional status, tumor spread, ascites, and prior chemotherapy and radiotherapy and can be used to evaluate patients at the time of presentation with intestinal obstruction and to help select optimal treatment for palliation.
Protoheme extraction from plant tissue

A method for reproducibly estimating the protoheme content of plant tissues has been developed. The tissue sample is homogenized in 80% acetone to remove pigments and lipids; protoheme is then extracted from the tissue residue with 2% HCl in acetone and quantitatively transferred into diethyl ether. After evaporation of the ether, the residue is dissolved in alkaline pyridine, and the protoheme concentration is estimated from a dithionite-reduced-minus-ferricyanide-oxidized spectrum. When compared to some other methods, this procedure gives consistently higher yields.
Emissions Analysis of Southern California Metrolink Commuter Rail

The Southern California Regional Rail Authority began constructing a new commuter rail system called Metrolink in October 1992. When complete, the Metrolink system will form the nation's sixth largest commuter rail system and is expected to alleviate congestion and help obtain better air quality. To estimate the air quality impact, emissions of CO, HC, NOx, and PM associated with an automobile-only—based commute and a Metrolink-based commute from Riverside to Los Angeles are compared. Analysis of the Metrolink-based commuting scenario includes the emissions from the home-to-station automobile trip and the Metrolink diesel locomotive emissions. Essential data for the automobile emissions modeling process were obtained through a survey of Metrolink passengers and through remote emissions sensing of Metrolink passenger vehicles. Train emissions were estimated using emission rate data provided by recent diesel locomotive studies. Results indicated that at current ridership levels there is a reduction in total...
The potential for reuse of plastics recovered from solid wastes

Plastics in solid wastes is a problem of growing concern. Recycling of wastes is currently believed to be the most acceptable form of disposal in the long run; however, this route is known to be especially difficult for plastics. Recycling would be easier if the various generic types present in solid wastes, mainly polyethylene, polystyrene and poly (vinyl chloride), could be isolated; however, this would be very difficult and expensive. This is a first report on research aimed at evaluating the potential of recycling plastics as a polymer blend of the various generic types. This approach suffers from the difficulty that the different plastics are incompatible and the blend has poor mechanical properties. The extent of this problem is documented with data on many ternary blends employing virgin polyethylene, polystyrene and poly (vinyl chloride) of numerous grades likely to be found in solid wastes. Property degradation was found to be more severe as the complexity of the blend increased, indicating that general municipal wastes could be reused only in very low grade applications, whereas certain commercial wastes might have brighter prospects. Strategies for improving blend properties are outlined.
Greedy Receivers in IEEE 802.11 Hotspots: Impacts and Detection

As wireless hotspot business becomes a tremendous financial success, users of these networks have increasing motives to misbehave in order to obtain more bandwidth at the expense of other users. Such misbehaviors threaten the performance and availability of hotspot networks and have recently attracted increasing research attention. However, the existing work so far focuses on sender-side misbehavior. Motivated by the observation that many hotspot users receive more traffic than they send, we study greedy receivers in this paper. We identify a range of greedy receiver misbehaviors, and quantify their damage using both simulation and testbed experiments. Our results show that even though greedy receivers do not directly control data transmission, they can still result in very serious damage, including completely shutting off the competing traffic. To address the issues, we further develop techniques to detect and mitigate greedy receiver misbehavior, and demonstrate their effectiveness.