cssi/SciSciGPT-SciSciNet huggingface dataset:
SU-GG-T-65: Dosimetric Verification of HDR Treatment Planning System Dose Calculations by Farmer Chamber Measurements in Water

Purpose: To evaluate the applicability of Farmer ion chambers for absolute dosimetry of high dose rate (HDR) brachytherapy sources in water and the potential to use this methodology for brachytherapytreatment planning system (TPS) dose calculation validation. Method and Materials: Water tank absolute dosimtric measurements of 192Ir doses were performed with a Farmer ionization chamber. Autoradiography was used for determination of absolute source position and subsequent alignment of the source with the chamber. A small solid water phantom was used for brachy catheter support. The phantom was immersed in a water tank equipped with a chamber holding mechanism capable of 1D motion. The chamber and the electrometer used for absolute dose measurements had ADCL traceable calibration factors for external beam reference dosimetry (calibrated in water with 60Co beam). Doses were measured from 2 cm to 11 cm away from a single dwell position. Measurements were compared to doses calculated by Oncentra HDR TPS as well as simple hand calculations, utilizing point source geometry, inverse square dose falloff and published data for radial dose falloff due to attenuation. Results: The measured and the TPS doses agreed within 3% up to 8 cm from the source, within 4% from 8 cm to 10 cm, and within 6% at 11 cm. The hand calculations, performed as a simple consistency check, agreed with the TPS within 1% across the entire tested range. Conclusions: The presented results indicate that Farmer chambers are suitable for absolute dosimetry of 192Ir sources over the useful HDR therapeutic range (2 cm to 10 cm). Absolute measurements in water performed with Farmer chambers can be easily employed for commercial TPS dosimetric commissioning as well as for routine dosimetric checks of the HDR delivery systems.
Magnetism and the Ground-State Energy of a Linear Chain. II. Configuration Interaction Effects

We continue the investigation, begun in the previous paper of this series, on the ground-state energy of a one-dimensional chain of atoms from the point of view of orthogonal atomic functions. Thus, the exchange integral is positive and the configuration interaction between polar and nonpolar states is included. Our results are extended to include the condition of a large amount of overlap among the unperturbed nonorthogonal atomic functions resulting in a strong interaction between the orthogonalized nonpolar and polar energy states for the case of two electrons having their spins oriented opposite to all other electron spins. These results indicate that for this case the energy of the unmagnetized state is lower than that obtained when all the electron spins are parallel and that the system is nonferromagnetic.
The characterization of scintillator performance at temperatures up to 400 degrees centigrade

Abstract The logging and characterization of geothermal wells requires improved scintillator systems that are capable of operation at temperatures significantly above those commonly encountered in the logging of most conventional oil and gas wells (e.g., temperatures nominally in the range of up to 150 °C). Unfortunately, most of the existing data on the performance of scintillators for radiation detection at elevated temperatures is fragmentary, uncorrelated, and generally limited to relatively low temperatures—in most cases to temperatures well below 200 °C. We have designed a system for characterizing scintillator performance at temperatures extending up to 400 °C under inert atmospheric conditions, and this system is applied here to the determination of scintillator performance at elevated temperatures for a wide range of scintillators including, among others: bismuth germanate, cadmium tungstate, cesium iodide, cesium iodide (Tl), cesium iodide (Na), sodium iodide, sodium iodide (Tl), lutetium oxy-orthosilicate (Ce), zinc tungstate, yttrium aluminum perovskite (Ce), yttrium aluminum garnet (Ce), lutetium aluminum perovskite (Ce), and barium fluoride, strontium iodide (Eu). Most of the scintillator samples exhibited severe degradation in light yield at elevated temperatures. Measurements were terminated at temperatures at which the measured light yield no longer appeared useful. The results of these high-temperature scintillator performance tests are described in detail here. Comparisons of the relative elevated-temperature properties of the various scintillator materials have resulted in the identification of promising scintillator candidates for high-temperature use in geothermal and fossil-fuel well environments.
Public Sociology: Problematics, Publicity, and Possibilities

In this issue we present six papers that deal in contrasting ways with the ongoing debate over public sociology. Considered collectively, the analyses portray the public sociology project as impossible or at least seriously hampered, but nevertheless newsworthy, diverse and sometimes triumphant. A true display of standpoint epistemology and multivocality. Darren Noy begins with a thoughtful and highly personal critique of the ideal of public sociology as embodied in the curriculum of the University of California at Berkeley. On the basis of his experience as a doctoral student in that program, Noy expresses concern that the very rubric of “public sociology” tends toward a moral critique of “professional” sociology. This, he believes, has created entrenched factions and has pulled the field ever more deeply into what he calls a “self-referential quagmire.” The way forward, he believes, is transdisciplinary research in collaboration with community actors, in the service of the common good. Joey Sprague and Heather Laube continue in a critical vein by examining structural barriers facing colleagues interested in doing public sociology. The authors are especially interested in the experiences of women in the field. They present findings based on interviews with fifty academic feminists and fifteen other feminists engaged with public sociology. Their data point to two especially pertinent factors: (1) what the authors call the culture of professional sociology; and (2) established standards for evaluating scholarship. Sprague and Laube conclude with several recommendations for facilitating high-quality public sociology. Mathias Revers takes the discussion in a more positive, as well as international, direction through an examination of sociologists featured in the Austrian press. He Am Soc (2009) 40:233–234 DOI 10.1007/s12108-009-9082-1
An index to measure risk co-relationships in engineering enterprise systems

This paper presents an index that measures the impacts of dependency risks between parts of an enterprise which can negatively affect the ability of the whole enterprise to deliver capabilities and services. This measure will be termed the risk co-relationship index. The purpose of this index is to enable engineers and managers to identify and evaluate the ripple effects of risks from one part of an enterprise to another. Presenting a way to model and measure these effects advances engineering management practice by allowing engineers and managers to consider dependency risks and use the index in decisions on resource allocation and enterprise design and implementation.
Communicating behind the scenes: A primer on radio frequency identification (RFID):

Mobile media researchers have increasingly focused on smartphones as locative media. However, our field has not devoted as much attention to another mobile technology used to track far more people and things than smartphones: radio frequency identification (RFID) tags. RFID tags are used to track products and people, and they are an increasingly important part of the infrastructure of the Internet of Things. This article argues that mobile media scholars have much to contribute to scholarly analyses of RFID. I make that argument by first giving background on RFID as a mobile technology. I then identify and discuss four areas of research related to RFID tags—Big Data, surveillance, space and place, and nonhuman agency—that are particularly relevant to mobile media scholars.
Recommending Documents for Complex Question Exploration by Analyzing Browsing Behavior

We present a novel approach for recommending documents to users by analyzing user browsing behavior, and demonstrate the effectiveness of our methods using an original data set.
Episodic Acyclovir Therapy as Part of Syndromic Management Among Men Presenting With Genital Ulcer Disease: Is There Benefit?

Herpes simplex virus type 2 (HSV-2) is the most common cause of genital ulcer disease (GUD) throughout the world [1]. This often asymptomatic infection is present in about 1 in 5 Americans (17.0%; 95% CI, 15.8%–18.3% in 1999–2004) [2] and prevalence may exceed 80% in individuals residing in developing countries [1]. Despite the often asymptomatic nature of genital herpes, several studies document the role of HSV-2 infection in increasing genital and plasma HIV-1 viral load, which may, in turn, increase HIV transmission [3]. Episodic acyclovir therapy may result in decreased genital HIV-1 shedding and enhance ulcer healing in individuals receiving syndromic therapy for GUD but no study has specifically addressed this issue in men.
Rapid Formation of Ice Giant Planets

Abstract The existence of Uranus and Neptune presents severe difficulties for the core accretion model for the formation of ice giant planets. We suggest an alternative mechanism, namely disk instability leading to the formation of gas giant protoplanets, coagulation and settling of dust grains to form ice–rock cores at their centers, and photoevaporation of their gaseous envelopes by a nearby OB star, as a possible means of forming ice giant planets.
Halfway to Nowhere: Liberian Former Child Soldiers in a Ghanaian Refugee Camp

This study utilizes Kunz's kinetic model of refugee displacement to interpret the placelessness experienced by Liberian former child soldiers in the Buduburam refugee camp in Ghana. From August to ...
Construction of a Utopian West: The Russian Nineteenth-Century Intelligentsia

A person’s image of a foreign country is often not related to an actual encounter, but limited and one-sided based on the environment of the person’s native land. Consider, for example, the Russian elite perception of the West in the eighteenth and early nineteenth centuries. Peter the Great’s reign shook Russia’s traditional society and led to the spread of promiscuity and general immorality. Consequently, for many Russians, whether or not they traveled, the West, epitomized by France, was a place of erotic pleasures and easygoing life. By the beginning of the nineteenth century some members of the Russian elite started to question the political system of their native land. For some of them, like Peter Chaadaev, the West stood as a symbol of the ideal political institutions and Russia for the dead end of history.
Cardiac Tuberculosis: TB of the Endocardium

Tuberculosis involving the endocardium is extremely rare. The diagnosis is usually made during autopsy. Often there is involvement of other parts of the heart as well as other regions of the body. The infection is a result of direct extension from the myocardium or hematogenous spread. Two cases of disseminated tuberculosis with endocardial involvement are reported. In Case 1 miliary tuberculosis was diagnosed during life but the patient succumbed to extensive disease on the third hospital day. The patient in Case 2 presented with congestive cardiac failure and the possibility of tuberculosis was not suspected during life.
Cosmic antiproton spectrum measurement modelling with the AMS-02 detector at ISS

Abstract The results of the MC feasibility study of the AMS-02 Detector cosmic-ray p spectrum measurement capability are presented. AMS will be able to provide accurate measurements of the above spectrum in a broad energy range (up to hundreds of GeV) with a few percent energy resolution. The AMS p acceptance has been estimated to be around 0.16 m 2 sr for low energy particles and 0.03 m 2 sr for high energy ones, with maximal opening angle of 35° and 20° correspondingly. The systematic study of the background events has been done, the irreducible background to signal ratio below a few percent level being obtained.
Radical SAM enzyme QueE defines a new minimal core fold and metal-dependent mechanism

7-carboxy-7-deazaguanine synthase (QueE) catalyzes a key S-adenosyl-L-methionine (AdoMet)- and Mg(2+)-dependent radical-mediated ring contraction step, which is common to the biosynthetic pathways of all deazapurine-containing compounds. QueE is a member of the AdoMet radical superfamily, which employs the 5'-deoxyadenosyl radical from reductive cleavage of AdoMet to initiate chemistry. To provide a mechanistic rationale for this elaborate transformation, we present the crystal structure of a QueE along with structures of pre- and post-turnover states. We find that substrate binds perpendicular to the [4Fe-4S]-bound AdoMet, exposing its C6 hydrogen atom for abstraction and generating the binding site for Mg(2+), which coordinates directly to the substrate. The Burkholderia multivorans structure reported here varies from all other previously characterized members of the AdoMet radical superfamily in that it contains a hypermodified (β6/α3) protein core and an expanded cluster-binding motif, CX14CX2C.
An Observable Peculiarity of the Brans-Dicke Radiation Zone

It is pointed out that the Brans-Dicke theory predicts a transverse spin-0 component of the $O({r}^{\ensuremath{-}1})$ radiative Riemann tensor. Unlike the conventional spin-2 radiative Riemann tensor, monopole oscillations may serve as a source. Under favorable conditions, neutron star formation within our galaxy will be detectable by Weber's gravitational-wave receiver.
Gay and lesbian issues in residency training at u.s. Psychiatry programs.

The authors conducted a survey that explored the training milieu of gay and lesbian psychiatric residents at various sites throughout the United States. In some ways, the residents surveyed have greater institutional support than was found in an earlier study of homosexual medical students. But there are clear and disturbing differences among residents based on gender, with men more likely than women to consider their program supportive of their sexual orientation. In spite of this relative advantage, gay men and lesbians, medical students and residents alike, would prefer that their training institutions be more supportive of their sexuality and more adept at facilitating sensitive care of homosexual patients.
Missense meanderings in sequence space: a biophysical view of protein evolution

Proteins are finicky molecules; they are barely stable and are prone to aggregate, but they must function in a crowded environment that is full of degradative enzymes bent on their destruction. It is no surprise that many common diseases are due to missense mutations that affect protein stability and aggregation. Here we review the literature on biophysics as it relates to molecular evolution, focusing on how protein stability and aggregation affect organismal fitness. We then advance a biophysical model of protein evolution that helps us to understand phenomena that range from the dynamics of molecular adaptation to the clock-like rate of protein evolution.
Hierarchical Phosphorylation within the Ankyrin Repeat Domain Defines a Phosphoregulatory Loop That Regulates Notch Transcriptional Activity

The Notch signal transduction pathway mediates important cellular functions through direct cell-to-cell contact. Deregulation of Notch activity can lead to an altered cell proliferation and has been linked to many human cancers. Casein kinase 2 (CK2), a ubiquitous kinase, regulates several cellular processes by phosphorylating proteins involved in signal transduction, gene expression, and protein synthesis. In this report we identify NotchICD as a novel target of phosphorylation by CK2. Using mapping and mutational studies, we identified serine 1901, located in the ankyrin domain of Notch, as the target amino acid. Interestingly, phosphorylation of serine 1901 by CK2 appears to generate a second phosphorylation site at threonine 1898. Furthermore, threonine 1898 phosphorylation only occurs when Notch forms a complex with Mastermind and CSL. Phosphorylation of both threonine 1898 and serine 1901 resulted in decreased binding of the Notch-Mastermind-CSL ternary complex to DNA and consequently lower transcriptional activity. These data indicate that the phosphorylation of serine 1901 and threonine 1898 negatively regulates Notch function by dissociating the complex from DNA. This study identifies a new component involved in regulation of NotchICD transcriptional activity, reinforcing the notion that a precise and tight regulation is required for this essential signaling pathway.
Correlation of Cellular Activity in Weismann's Ring with Molting Cycles in Larvae of Musca autumnalis,

The hormonal effects of secretions from retrocerebral glands have been well established. However, correlation of these effects with gland cell activity is recorded for only a few insects, including the work of Wigglesworth (1951), Grandori (1956), and Ewen (1962). Cells in Weismann's ring of larvae of the face fly, Musca autumnalis De Geer, were studied histologically in an attempt to show the relationship between gland cell activity and molting.
Electrical Properties and the Strength of Electrorheological (ER) Fluids

The shear resistance or flow stress τ of electrorheological (ER) fluid suspensions can be considered to consist of two components.
Online suicide risk screening and intervention with college students: A pilot randomized controlled trial.

OBJECTIVE: This pilot randomized controlled trial examined the effect of an online intervention for college students at risk for suicide, Electronic Bridge to Mental Health Services (eBridge), which included personalized feedback and optional online counseling delivered in accordance with motivational interviewing principles. Primary outcomes were readiness to seek information or talk with family and friends about mental health treatment, readiness to seek mental health treatment, and actual treatment linkage. METHOD: Participants were 76 college students (45 women, 31 men; mean age = 22.9 years, SD = 5.0 years) at a large public university who screened positive for suicide risk, defined by at least 2 of the following: suicidal thoughts, history of suicide attempt, depression, and alcohol abuse. Racial/ethnic self-identifications were primarily Caucasian (n = 54) and Asian (n = 21). Students were randomized to eBridge or the control condition (personalized feedback only, offered in plain report format). Outcomes were measured at 2-month follow-up. RESULTS: Despite relatively modest engagement in online counseling (29% of students posted ≥1 message), students assigned to eBridge reported significantly higher readiness for help-seeking scores, especially readiness to talk to family, talk to friends, and see a mental health professional. Students assigned to eBridge also reported lower stigma levels and were more likely to link to mental health treatment. CONCLUSIONS: Findings suggest that offering students personalized feedback and the option of online counseling, using motivational interviewing principles, has a positive impact on students' readiness to consider and engage in mental health treatment. Further research is warranted to determine the robustness of this effect, the mechanism by which improved readiness and treatment linkage occurs, and the longer term impact on student mental health outcomes. (PsycINFO Database Record (c) 2015 APA, all rights reserved). Language: en
The characteristics of glucose transport across the blood brain barrier and its relation to cerebral glucose metabolism.

Normal neuronal function requires the presence of a suitable ionic and metabolic environment. It is well documented that in cerebral tissue, the interface between blood and brain is selectively permeable to plasma solutes. Therefore, this so-called “blood brain barrier” (BBB) plays a major role in maintaining the milieu interieur of the brain. A complete description of the barrier’s function must consider the relationship between transport and metabolism. The barrier could serve as a primary regulator of cerebral metabolism by controlling the entry rate of substrates into the brain and thus becoming the rate limiting step. On the other hand, the BBB may serve a more passive role by maintaining the cellular concentration of substrates whose rates of metabolism are regulated by other mechanisms. This is particularly relevant to glucose because most of the energy produced by the brain is derived from glucose metabolism.
A computerized physical simulator for training clinical prostate palpation skills

Cancer of the prostate is diagnosed at a high rate in American men and leads to a high number of deaths annually. Each of the three separate prostate diseases (benign prostatic hypertrophy, prostatitis, and cancer) has different palpable characteristics and requires different treatment. Therefore healthcare professionals must learn to correctly detect and diagnose each prostate abnormality. The digital rectal examination is a commonly employed method to detect prostate abnormalities. However, medical and nurse practitioner students often receive little to no training for this exam and trained clinicians often exhibit low agreement on findings. Both may be due, in part, to inadequacies of current training practices, particularly those involving simulation. The purpose of this work is to improve the current training. In particular, current simulators might more adequately prepare trainees if they included design characteristics such as basic elements of lifelike anatomy, multiple and reconfigurable scenarios with graded levels of difficulty, and feedback on trainee technique and performance. Also, the simulator must train practitioners to detect prostate cancer and other diseases of the prostate. This work presents the implementation of these design characteristics. The Virginia prostate examination simulator includes a freestanding torso structure, six instrumented prostates with embedded pressure sensors and controllable balloons, custom-built electronics to record sensor data and control balloon water pressure, and a user-interface display that presents technique and performance information to trainees.
Power minimization using simultaneous gate sizing, dual-Vdd and dual-Vth assignment

We develop an approach to minimize total power in a dual-Vdd and dual-Vth design. The algorithm runs in two distinct phases. The first phase relies on upsizing to create slack and maximize low Vdd assignments in a backward topological manner. The second phase proceeds in a forward topological fashion and both sizes and re-assigns gates to high Vdd to enable significant static power savings through high Vth assignment. The proposed algorithm is implemented and tested on a set of combinational benchmark circuits. A comparison with traditional CVS and dual-Vth/sizing algorithms demonstrate the advantage of the algorithm over a range of activity factors, including an average power reduction of 30% (50%) at high (nominal) primary input activities.
The Digital Identity Divide: How Technology Knowledge Impacts College Students

This article embraces the concept of technology identity as an innovative theoretical and methodological approach to study the digital divide. Reporting on qualitative data taken from a mixed-method study, the analytical approach goes beyond an access and skills perspective in measuring digital inequities. Narratives collected from students demonstrate how powerful sociocultural influences, such as family practices and access to a quality K-12 education, contribute to the development of a technology identity. The stories outlined in this article offer illustrative accounts of how holding a particular technology identity impacts the academic and social life of college students. Taken together, the narratives highlight the role of schools and universities as institutions which are perpetuating — rather than resisting — inequalities associated with the digital divide.
Improved flexible refinement of protein docking in CAPRI rounds 22–27

Since the fourth evaluation for critical assessment of prediction of interactions (CAPRI), we have made improvements in three major areas in our refinement approach, namely the treatment of conformational flexibility, the binding free energy model, and the search algorithm. First, we incorporated backbone flexibility into our previous approach, which only optimized rigid backbone poses with limited side-chain flexibility. Here, we formulated and solved the conformational search as a hierarchical optimization problem (involving rigid-body poses, backbone flexibility, and side-chain flexibility). Second, we used continuum electrostatic calculations to include solvation effects in the binding free energy model. Finally, we eliminated sloppy modes (directions in which the free energy is essentially constant) to improve the efficiency of the search. With these improvements, we produced correct predictions for 6 of the 10 latest CAPRI targets, including one high, three medium, and two acceptable accuracy predictions. Compared to our previous performance in CAPRI, substantial improvements have been made for targets requiring homology modeling.
Child Rearing and Compliance: Japanese and American Families in Houston

The relation between parental child-rearing practices and child compliance was examined in two groups of middle- to upper-middle-class parents in Houston, Texas: 20 Japanese families temporarily living in the city and 18 Caucasian American families. The children were 4- to 7-year-olds enrolled in summer sessions in a private preschool/elementary school. Mothers and fathers were interviewed separately about their child-rearing practices, and parents and teachers completed child behavior questionnaires. In both Japanese and American families, child compliance with adult authority was positively associated with providing opportunities for appropriate behavior and negatively associated with reliance on punishment and physical intervention. Japanese parents relied less than Americans on external punishments and more on verbal techniques alone. American parents were more likely to provide opportunities and to use praise. For Japanese families, the length of exposure to American culture was associated with predi...
Locus-Specific Ribosomal RNA Gene Silencing in Nucleolar Dominance

The silencing of one parental set of rRNA genes in a genetic hybrid is an epigenetic phenomenon known as nucleolar dominance. We showed previously that silencing is restricted to the nucleolus organizer regions (NORs), the loci where rRNA genes are tandemly arrayed, and does not spread to or from neighboring protein-coding genes. One hypothesis is that nucleolar dominance is the net result of hundreds of silencing events acting one rRNA gene at a time. A prediction of this hypothesis is that rRNA gene silencing should occur independent of chromosomal location. An alternative hypothesis is that the regulatory unit in nucleolar dominance is the NOR, rather than each individual rRNA gene, in which case NOR localization may be essential for rRNA gene silencing. To test these alternative hypotheses, we examined the fates of rRNA transgenes integrated at ectopic locations. The transgenes were accurately transcribed in all independent transgenic Arabidopsis thaliana lines tested, indicating that NOR localization is not required for rRNA gene expression. Upon crossing the transgenic A. thaliana lines as ovule parents with A. lyrata to form F1 hybrids, a new system for the study of nucleolar dominance, the endogenous rRNA genes located within the A. thaliana NORs are silenced. However, rRNA transgenes escaped silencing in multiple independent hybrids. Collectively, our data suggest that rRNA gene activation can occur in a gene-autonomous fashion, independent of chromosomal location, whereas rRNA gene silencing in nucleolar dominance is locus-dependent.
Belief-Based Decision Making for Service Migration

Service migration is an important strategy to improve a system's ability to survive malicious attacks and to continually provide mission-critical services. By moving the critical services from their compromised platforms to other clean, healthy platforms in order for those services to continuously function on those new platforms, further loss can be avoided in case of a devastating attack. Given the increasing complexity of malicious attacks and limited resources to fully assess any damage caused by attacks within a short period of time, damage assessment as provided by each intrusion detection agent is often incomplete or uncertain. By integrating multiple sources of damage assessments from different intrusion detection agents, a more reliable and trustworthy damage assessment can be formed about a platform of concern. Such a combined damage assessment is important in determining whether a service migration is necessary. We present a transferable belief-based decision model to represent and combine individual damage assessment outputs from multiple intrusion detection agents and then construct a comprehensive, more reliable output. A final decision can be made to choose the most effective and cost efficient security action to take in an intrusion scenario.
The evolution of data structures

For over 20 years, the data structures course has been a pillar of computer science programs at colleges and universities. This paper looks at how the data structures course has evolved over time from a course that emphasized algorithmic concepts to a course that emphasizes syntactical and design concepts. It illustrates how the evolution of programming languages and concepts can introduce "gratuitous" complexity into algorithms. Specific algorithms and abstract data types are compared in past and present data structures texts using a suite of software metrics. A comparison is performed between algorithms from data structures texts across different programming languages and across procedural and object oriented paradigms. The results are compared to provide evidence of how the course has evolved over time.
Canada’s new ethical guidelines for research with humans: a critique and comparison with the United States

Canada’s Tri-Council Policy Statement: Ethical conduct for research involving humans, first published in 1998, has recently been updated.[1][1] The US Department of Health and Human Services has just issued an Advance Notice of Proposed Rulemaking that would substantially change the 20-year-old
Calcium-Activated Potassium Conductances Contribute to Action Potential Repolarization at the Soma But Not the Dendrites of Hippocampal CA1 Pyramidal Neurons

Evidence is accumulating that voltage-gated channels are distributed nonuniformly throughout neurons and that this nonuniformity underlies regional differences in excitability within the single neuron. Previous reports have shown that Ca2+, Na+, A-type K+, and hyperpolarization-activated, mixed cation conductances have varying distributions in hippocampal CA1 pyramidal neurons, with significantly different densities in the apical dendrites compared with the soma. Another important channel mediates the large-conductance Ca2+-activated K+ current (IC), which is responsible in part for repolarization of the action potential (AP) and generation of the afterhyperpolarization that follows the AP recorded at the soma. We have investigated whether this current is activated by APs retrogradely propagating in the dendrites of hippocampal pyramidal neurons using whole-cell dendritic patch-clamp recording techniques. We found noIC activation by back-propagating APs in distal dendritic recordings. Dendritic APs activatedIC only in the proximal dendrites, and this activation decayed within the first 100–150 μm of distance from the soma. The decay of IC in the proximal dendrites occurred despite AP amplitude, plus presumably AP-induced Ca2+ influx, that was comparable with that at the soma. Thus we conclude that IC activation by action potentials is nonuniform in the hippocampal pyramidal neuron, which may represent a further example of regional differences in neuronal excitability that are determined by the nonuniform distribution of voltage-gated channels in dendrites.
F-actin bundles direct the initiation and orientation of lamellipodia through adhesion-based signaling

Mesenchymal cells such as fibroblasts are weakly polarized and reorient directionality by a lamellipodial branching mechanism that is stabilized by phosphoinositide 3-kinase (PI3K) signaling. However, the mechanisms by which new lamellipodia are initiated and directed are unknown. Using total internal reflection fluorescence microscopy to monitor cytoskeletal and signaling dynamics in migrating cells, we show that peripheral F-actin bundles/filopodia containing fascin-1 serve as templates for formation and orientation of lamellipodia. Accordingly, modulation of fascin-1 expression tunes cell shape, quantified as the number of morphological extensions. Ratiometric imaging reveals that F-actin bundles/filopodia play both structural and signaling roles, as they prime the activation of PI3K signaling mediated by integrins and focal adhesion kinase. Depletion of fascin-1 ablated fibroblast haptotaxis on fibronectin but not platelet-derived growth factor chemotaxis. Based on these findings, we conceptualize haptotactic sensing as an exploration, with F-actin bundles directing and lamellipodia propagating the process and with signaling mediated by adhesions playing the role of integrator.
"Bad Habits" in Quantum Mechanics

There are two common “bad habits” in the description, analysis, interpretation and teaching of fundamental aspects of quantum mechanics. One is the all too casual use of the term “information”, without making it explicitly clear which of the various types, Shannon, algorithmic or pragmatic, are meant. The other concerns the use of the term “knowledge”, without alluding to specific aspects of human brain function, for instance, when the observer selects the “system under study”, formulates simplified models, asks theoretical questions, plans an experiment, decides what to measure, prepares the system, chooses initial conditions, anticipates to obtain certain results and confirms a final state. I will show how an objective definition of information and recent results about information-processing in the brain help overcome the most common counter-intuitive aspects of quantum mechanics. In particular, I will discuss entanglement, teleportation, non-interaction measurements and decoherence in the light of the fact that the concept of pragmatic information, the one our brain handles, can only be defined in the macroscopic domain. Counter-intuitive aspects arise when we construct mental images of quantum systems in which the concept of pragmatic information is illegitimately forced into the quantum domain.
Structural determinants of purple membrane assembly.

The purple membrane is a two-dimensional crystalline lattice formed by bacteriorhodopsin and lipid molecules in the cytoplasmic membrane of Halobacterium salinarum. High-resolution structural studies, in conjunction with detailed knowledge of the lipid composition, make the purple membrane one of the best models for elucidating the forces that are responsible for the assembly and stability of integral membrane protein complexes. In this review, recent mutational efforts to identify the structural features of bacteriorhodopsin that determine its assembly in the purple membrane are discussed in the context of structural, calorimetric and reconstitution studies. Quantitative evidence is presented that interactions between transmembrane helices of neighboring bacteriorhodopsin molecules contribute to purple membrane assembly. However, other specific interactions, particularly between bacteriorhodopsin and lipid molecules, may provide the major driving force for assembly. Elucidating the molecular basis of protein^protein and protein^lipid interactions in the purple membrane may provide insights into the formation of integral membrane protein complexes in other systems. fl 2000 Elsevier Science B.V. All rights reserved.
Evaluation of a 4 mm x 4 mm SiC GTO at Temperatures up to 150°C and Varying Pulse Width

The U. S. Army Research Laboratory (ARL) is evaluating silicon carbide Super GTOs (SGTOs) to determine the extent of silicon carbide's capabilities as a possible replacement for silicon in future pulsed switching applications. Individual SiC die measuring 4 mmtimes4 mm were pulsed at high temperatures and varying pulse widths. These SGTOs were switched in an RLC circuit at temperatures up to 150 degC. At this peak temperature, they were switched as high as 3.2 kA and repetitively pulsed at 2.6 kA and 5 Hz for greater than 14,000 pulses. A pulse forming network (PFN) was also designed to increase the pulse width and the action seen by the SiC devices. At ambient temperature and a peak current of 2 kA, SiC SGTOs were switched in the PFN at a 50% pulse width of 40 mus and an action of 150 A2s. This report includes further data on high temperature and wide pulse width testing, as well as analysis of the devices' failure points
Preparation and water absorptive capacity of sodium cellulose carboxylate

Sodium cellulose carboxylate was prepared by oxidation of cellulose with gaseous nitrogen dioxide followed by treatment with buffer at pH 7.0. The oxidation reaction rate increased with higher initial gas flow rates, higher total weights of nitrogen dioxide and with nitrogen dioxide pressures higher than 1 atmosphere. Moisture acts as a weak catalyst but is also responsible for loss of nitrogen dioxide by formation of nitrogen acids. Sodium cellulose carboxylate absorbs much more water than cellulose. It is formed without loss of fibrous character or gel formation and with high water absorptivity only if an efficient buffer is used at pH 6.5 to 7.0. Higher pH levels lead to gel formation; lower pH levels lead to impaired absorptivity. Salt formation rate appears to be a diffusion controlled process which is highly sensitive to localized depletion of buffer solution. Use of NaOH in place of buffer does not give the highly absorbent salt. Gelation occurs instead. The diameter of 6-carboxy cellulose fibers prepared from softwood pulp increases about 90% during the pH 7.0 buffer treatment.
Preparation of Polypeptide-Dye Multilayers by an Electrostatic Assembly Process

To develop novel optical thin films, we have prepared self-assembled polypeptide films by an electrostatic process. The films were placed on a glass slide previously silanized by an amino silane and given a positive charge by immersion in aqueous acid. Subsequent immersion of the slide in aqueous anionic solutions of either poly(L-glutamic acid), congo red, copper phthalocyanine tetrasulfonic acid or p-nitroaniline-modified poly(L-glutamic acid) resulted in deposition of the anions on the surface. Following anionic immersion, the slides were dipped into a cationic poly(L-lysine) solution. Alternate dipping into anionic and cationic solutions yielded multilayers. The thin films were characterized by optical absorption and circular dichroism. The optical density increased with dipping cycles. Circular dichroism measurements of the thin films showed induced dichroism of the congo red and phthalocyanine-containing films, suggesting formation of a locally ordered dye-polypeptide complex. Solution circular dichroism measurements of the polypeptides indicated a coil conformation, while poly(Lglutamic acid)/poly(L-lysine) complexes showed circular dichroism spectrum characteristic of a s-sheet.
In vitro import of a nuclearly encoded tRNA into the mitochondrion of Trypanosoma brucei.

All of the mitochondrial tRNAs of Trypanosoma brucei have been shown to be encoded in the nucleus and must be imported into the mitochondrion. The import of nuclearly encoded tRNAs into the mitochondrion has been demonstrated in a variety of organisms and is essential for proper function in the mitochondrion. An in vitro import assay has been developed to study the pathway of tRNA import in T. brucei. The in vitro system utilizes crude isolated trypanosome mitochondria and synthetic RNAs transcribed from a cloned nucleus-encoded tRNA gene cluster. The substrate, composed of tRNASer and tRNALeu, is transcribed in tandem with a 59-nucleotide intergenic region. The tandem tRNA substrate is imported rapidly, while the mature-size tRNALeu fails to be imported in this system. These results suggest that the preferred substrate for tRNA import into trypanosome mitochondria is a precursor molecule composed of tandemly linked tRNAs. Import of the tandem tRNA substrate requires (i) a protein component that is associated with the surface of the mitochondrion, (ii) ATP pools both outside and within the mitochondrion, and (iii) a membrane potential. Dissipation of the proton gradient across the inner mitochondrial membrane by treatment with an uncoupling agent inhibits import of the tandem tRNA substrate. Characterization of the import requirements indicates that mitochondrial RNA import proceeds by a pathway including a protein component associated with the outer mitochondrial membrane, ATP-dependent steps, and a mitochondrial membrane potential.
Characteristics of Cloud-to-Ground Lightning Associated with Violent Tornadoes

Abstract Cloud-to-ground (CG) lightning patterns were analyzed in 42 violent tornado-producing (F4, F5) supercells that occurred between January 1989 and November 1992. The purpose of this analysis was to identify potential correlations between CG lightning patterns and tornadogenesis. Lightning characteristics were analyzed for a 30-min period before, during, and 30 min after each tornado’s lifetime. Thirty-one of the storms were characterized by a peak in CG flash rate preceding tornado formation; 20 storms displayed a decrease in CG flash activity coincident with tornado touchdown. Six of the 42 storms exhibited a polarity reversal, from positive to negative, in the sign of the charge lowered to ground. Storms exhibiting a majority of positive flashes were generally associated with long-track tornadoes, F5 damage ratings, or severe weather outbreak conditions. The total number of flashes associated with each storm had no correlation with tornadogenesis (total number of flashes ranged from 16 to 3394). ...
Recent developments in HLA-haploidentical transplantations

While allogeneic hematopoietic stem cell transplantations have a curative potential, several patients with hematologic malignancies cannot avail themselves of this therapeutic option due to lack of matched donor availability. Although HLA-haploidentical transplantations were previously associated with poor outcomes, recent evidence with use of post transplantation cyclophosphamide indicate improved safety and efficacy. The following paper discusses the most recent developments in this area.
Suppression of YAG phase formation in YAP:Ce pellets

It is difficult to obtain the pure YAP phase in YAP:Ce pellets synthesized by solid-state reaction at high temperature (up to 1500 °C), because a small amount of YAG (Y3Al5O12):Ce tends to form, resulting in additional emission and degrading the scintillation performance. We attempted three methods to suppress the formation of this YAG phase: a) codoping with Ca, B and Ba, b) adding Ba and F compounds as flux, and c) adding excess Y. The presence or absence of a YAG phase in the YAP pellets was determined by photoluminescence (PL), radioluminescence (RL) and reflectivity spectra. The most significant suppression of the YAG phase was achieved by adding 10% excess Y, after which the YAG emission peak was nearly completely suppressed in the RL and PL spectra, and no YAG phase absorbance was found in reflectivity spectra compared to stoichiometric YAP pellets.
A COMPARATIVE ASSESSMENT OF PHARMACOLOGICALLY ACTIVE PRINCIPLES AND ANTIOXIDANT ACTIVITY OF COMMONLY OCCURRING MUCUNA SPS. IN INDIA

The genus Mucuna (Fabaceae) includes about 150 species and almost all the species are reported to contain L-3,4-dihydroxy phenylalanine (L-Dopa), a non-protein amino acid that acts as precursor for the neurotransmitter dopamine, used in the treatment of Parkinsonâ€™s disease. The present study was aimed to assess the pharmacologically active principles and antioxidant activities of Mucuna pruriens (L.) DC., Mucuna bracteata DC., Mucuna cochinchinensis (Lour.) A. Chev. black seeds sp. and Mucuna cochinchinensis (Lour.) A. Chev. white seeds sp. The aqueous extract of plant material was subjected to assess the pharmacologically active principles by using L-dopa quantification, determination of protein and flavonoids, total phenolic content, Inhibition of DPPH radical and Reducing power/Ferric reducing antioxidant potential (FRAP) assays. The results obtained showed that, Mucuna cochinchinensis black seeds sp. has highest protein, total phenolic content, L-dopa content and DPPH radical scavenging activity. Mucuna bracteata seeds showed highest flavonoid content whereas, in FRAP assay Mucuna pruriens extract showed highest potential to reduce the ferric ions. It can be concluded from this study that, L-DOPA possesses antioxidant activity which was supported by in-vitro antioxidant assays. This indicates that the antioxidant activity of the aqueous extracts of all the Mucuna sps. may be due to the presence of L-Dopa content in its seed.
Energy Levels, Wave Functions, Dipole and Quadrupole Transitions of Fe+++ Ions in Sapphire.

A computation is made of energy levels, wave functions and transition probabilities of the Fe3+ ion in Al2O3. The crystal field parameters used were those determined by Symmons and Bogle at 4 K. The magnetic field direction is described by the angles θ and φ indicating the directions with respect to and around the c axis of the crystal. The values of θ go from 0 to π/2 with π/12 intervals, the angles φ are 0 and 2π/3 corresponding to the two nonequivalent sites of the crystal. The transition probabilities are given for dipole radiation in three polarization directions and for ultrasonic work the six components of the quadrupole transitions were computed.
Abrasion of rubber by a blade abrader : Effect of blade sharpness and test temperature for selected compounds

Abstract Apparatus has been constructed to abrade the flat surface of a rubber disk by rotating it against a stationary knife-blade scraper at constant frictional torque. The ratio of worn surface area to sample volume is relatively large, giving high sensitivity of measurement. Rates of abrasion were measured for several rubber compounds over a range of frictional torque from 0.05 to 1.2 Nm, corresponding to frictional work input from 150 to 3,600 J/m2 per rotation. For some materials, notably SBR compounds, the rate of abrasion decreased markedly as the experiment continued, due to rapid wear and blunting of the blade. Polybutadiene compounds caused much slower wear. Different blades were worn away at different rates, a zirconia blade showing the least wear. Also different elastomers showed different sensitivities to blade sharpness, the rate of abrasion of a high-styrene (48%) SBR compound being reduced the most with a blunted blade whereas the abrasion rate of polybutadiene (BR) was much less affected...
The Religion of Bill Clinton

President William Jefferson Clinton is one of the most complex, enigmatic persons to ever occupy the American presidency and there is little doubt that long after Clinton’s controversial presidency, scholars, and citizens alike will continue to puzzle over questions relating to his personality, character, and religious life.
23. Housman's to an Athlete Dying Young

(1953). 23. Housman's to an Athlete Dying Young. The Explicator: Vol. 11, No. 4, pp. 47-50.