cssi/SciSciGPT-SciSciNet huggingface dataset:
SU-E-J-226: Efficient Use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for Cervical-Cancer Brachytherapy

Purpose: To investigate image modality selection in an environment with limited access to interventional MRI for image-guided high-dose-rate cervical-cancer brachytherapy. Methods: Records of all cervical-cancer patients treated with brachytherapy between 1/2013 and 8/2014 were analyzed. Insertions were performed under CT guidance (CT group) or with >1 fraction under 3T MR guidance (MRI group; subMRI includes only patients who also had a CT-guided insertion). Differences between groups in clinical target volume (CTV), disease stage (I/II or III/IV), number of patients with or without interstitial needles, and CTV D90 were investigated. Statistical significance was evaluated with the Student T test and Fisher test (p <0.05). Results: 46 cervical-cancer patients were included (16 MRI [3 subMRI], 30 CT). CTV: overall, 55±53 cm3; MRI, 81±61 cm3; CT, 42±44 cm3 (p = 0.017). Stage: overall, 24 I/II and 22 III/IV; MRI, 3 I/II and 13 III/IV; CT, 21 I/II and 9 III/IV (p = 0.002). Use of needles: overall, 26 without and 20 with; MRI, 5 without and 11 with; CT, 21 without and 9 with (p = 0.015). CTV D90: overall, 82±5 Gy; MRI, 81±6 Gy; CT, 82±5 Gy (p = 0.78). SubMRI: CTV and D90 (as % of nominal fraction dose) were 23±6more » cm3 and 124±3% for MRI-guided insertions and 21±5 cm3 (p = 0.83) and 106±12% (p = 0.15) for CT-guided insertions. Conclusion: Statistically significant differences in patient population indicate preferential use of MRI for patients with high-stage disease and large residual CTVs requiring the use of interstitial needles. CTV D90 was similar between groups, despite the difference in patient selection. For patients who underwent both CT and MRI insertions, a larger MR CTV D90 and similar CTVs between insertions were observed. While MRI is generally preferable to CT, MRI selection can be optimized in environments without a dedicated MRI brachytherapy suite. This work was partially funded by the NIH R21 CA167800 (PI: Viswanathan; aviswanathan@partners.org)« less
A high performance low temperature 0.3 mu m CMOS on SIMOX

It is shown that ultrathin SOI offers a device design advantage for operation of CMOS circuits at 77 K. The use of ultrathin SOI makes it possible to achieve low threshold at relatively high channel doping, which is necessary for reduction of short channel effects. Very-high-performance loaded NAND inverters (with delays of less than 100 ps at 2 V) were fabricated. >
Reversion of acridine mustard-induced ad-3 mutants of Neurospora crassa

Abstract Previous analysis of adenine-3 ( ad-3 ) mutants of Neurospora crassa induced by the acridine mustard, 2-methoxy-6-chloro-9-[3-(ethyl-2-chloroethyl)aminopropylaamino]-acridine · 2HCl (ICR-170), suggested a number of possible mutagenic events for this compound including: ( I ) extended intragenic alterations covering more than one site, such as deletions; (2) base-pair substitutions (transitions or transversions) with a high degree of site specificity; and (3) additions and/or deletions of one or more base pairs (frameshift mutations). The revertibility of ICR-170-induced ad-3 mutants has been studied with ICR-170 and nitrous acid. A majority ( 16 24 ) of the ICR-170-induced mutants were clearly reverted by ICR-170, while none of the mutants were clearly reverted by nitrous acid. Genetic analysis of the ICR-170-induced revertants did not provide evidence for suppressor mutation. The ICR-170-induced revertants had the same growth rate as ad-3 + strains. Each of the ICR-170 components (acridine and nitrogen mustard) tested separately did not revert an ICR-170-revertible strain. The data indicate that the mutagenic events induced by ICR-170 at the ad-3 region of N. crassa are predominantly single-site, nontransitional alterations, probably of the frameshift type.
Functional roles of conserved amino acid residues surrounding the phosphorylatable histidine of the yeast phosphorelay protein YPD1

The histidine-containing phosphotransfer (HPt) protein YPD1 is an osmoregulatory protein in yeast that facilitates phosphoryl transfer between the two response regulator domains associated with SLN1 and SSK1. Based on the crystal structure of YPD1 and the sequence alignment of YPD1 with other HPt domains, we site-specifically engineered and purified several YPD1 mutants in order to examine the role of conserved residues surrounding the phosphorylatable histidine (H64). Substitution of the positively charged residues K67 and R90 destabilized the phospho-imidazole linkage, whereas substitution of G68 apparently reduces accessibility of H64. These findings, together with the effect of other mutations, provide biochemical support of the proposed functional roles of conserved amino acid residues of HPt domains.
Emergence of Rifampin-resistance in Chlamydia trachomatis

RIFAMPIN exerts marked antibacterial action through the inhibition of DNA-dependent RNA polymerase. Rifampin is used clinically in treatment of tuberculosis, meningo-coccal carrier states, and some other bacterial infections. In all types of bacteria examined, the incidence of rifampin-resistant mutants was high1,2. Thus the wisdom of using rifampin as the sole drug in a chronic infection where protracted treatment might be required for cliincal cure has been questioned.
Quantum Theory of Gravity. III. Applications of the Covariant Theory

The basic momentum-space propagators and vertices (including those for the fictitious quanta) are given for both the Yang-Mills and gravitational fields. These propagators are used to obtain the cross sections for gravitational scattering of two scalar particles, scattering of gravitons by scalar particles, graviton-graviton scattering, two-graviton annihilation of scalar-particle pairs, and graviton bremsstrahlung. Special features of these cross sections are noted. Problems arising in renormalization theory and the role of the Planck length are discussed. The gravitational Ward identity is derived, and the structure of the radiatively corrected 1-graviton vertex for a scalar particle is displayed. The Ward identity is only one of an infinity of identities relating the many-graviton vertex functions of the theory. The need for such identities may be eliminated in principle by computing radiative corrections directly in coordinate space, using the theory of manifestly covariant Green's functions. As an example of such a calculation, the contribution of conformal metric fluctuations to the vacuum-to-vacuum amplitude is summed to all orders. The physical significance of the renormalization terms is discussed. Finally, Weinberg's treatment of the infrared problem is examined. It is not difficult to show that the fictitious quanta contribute negligibly to infrared amplitudes, and hence that Weinberg's use of the DeDonder gauge is justified. His proof that the infrared problem in gravidynamics can be handled just as in electrodynamics is thereby made rigorous.
Modeling a fibre channel switch with stochastic Petri nets

Gianfranco Ciardo Dept. of Computer Science, College of William and Mary Williamsburg, VA 23187-8795, USA ciardo@cs.wm.edu Ludmila Cherkasova, Vadim Kotov, and Tomas Rokicki Hewlett-Packard Labs 1501 Page Mill Road, Palo Alto, CA 94303, USA fcherkasova,kotov,rokickig@hpl.hp.com As computing systems become increasingly complex and concurrent, performance analysis becomes more important, especially when designing an overall architecture. Simple numerical approximations can often yield bounds on performance. Queueing theory and Markovian analysis can provide insight into the steady-state performance of the system. Discreteevent simulation can provide a more detailed view of the system behavior. We used all of the above techniques in the performance study of a Fibre Channel switch. An approximate stochastic Petri net (SPN) model was employed, obtained by exploiting symmetries in the system. The most challenging aspect was determining transition ring probabilities that accurately re ected the dynamic behavior of the exact SPN. This model was valided against a detailed simulation and found to be accurate within 3%. See [1] for details and references. 1 System description We consider a switch with N ports, numbered from 0 to N 1 (Fig. 1). The switch contains bu er pools organized by input port, a router to transfer header information to output queues, and a scheduler to schedule the transfer of data from an input bu er across the crossbar to an output port. When a message arrives at a port, it is read into a bu er as soon as one is available. The router cyclically polls each port, bypassing ports without new messages. During the poll of a particular port, the router reads the header information of the new message and inserts it into a scheduler table. This table is organized as N FIFO queues, one per output port. The router starts routing a message as soon as the header is in 0 1 N-1 Input Port 0 B slots
Cholinesterase measurements with an automated kit.

Background The Test-mate kit determines acetylcholinesterase (AChE, EC 3.1.1.7) and hemoglobin content of a drop of blood, displaying enzyme activities normalized to 25°C. Previous models produced inconsistent results at different temperatures. This report focuses on the current model, ChE 400, and two instruments of a previous OP model. Methods AChE activities were determined by the Ellman assay, using the three kits and a 96-well microplate reader. Temperatures ranged from 10 to 37°C. Fetal bovine serum was the source of AChE. Results Normalized activities decreased below 20°C in the ChE model and below 25°C in the OP models. Activities of the same serum sample differed between the three Test-mate kits, ranging from 1.03 to 1.49 μmoles/min/ml. Percent errors were greater than with the microplate reader at all temperatures. Conclusions Neither we nor the manufacturer recommend the current Test-mate model for fieldwork. Nevertheless, there have been field measurements with Test-Mate kits, and we recommend that an enzyme activity standard be run in parallel with their use.
The re-election of US President Barack Obama.

A narrow but clear victory with profound consequences for healthcare Having survived constitutional and political challenges, the implementation of the Patient Protection and Affordable Care Act in the United States is secure. On 6 November 2012, Democratic President Barack Obama was elected to a second term, narrowly but clearly defeating Republican Mitt Romney. Romney’s vow to “repeal and replace” the healthcare reforms known as “Obamacare” was a key aspect of his campaign. With Obama’s victory, millions of people will gain health insurance over the next decade, either through the private market or the expansion of Medicaid, a joint federal-state insurance program for people with low income or certain disabilities. In addition, the structure of Medicare, the federal insurance program for elderly and disabled people, should be retained. The US presidential election was very close; a shift of several hundred thousand votes (out of more than 118 million votes cast nationally) in a handful of battleground states—including Florida, Ohio, and Virginia—could have given Romney the 270 electoral votes needed for victory, and, possibly, the power to block various aspects …
The Metabolic Needs of Critically Ill Children and Neonates

The pediatric metabolic response to injury and operation is proportional to the degree of stress and causes an increase in the turnover of proteins, fats, and carbohydrates. Thereby, substrates are made readily available for the immune response and wound healing. Because this process requires energy, the resting energy expenditure of ill patients increases. Whole-body protein degradation rates are elevated out of proportion to synthetic rates, and negative protein balance also ensues. Neonates and children are particularly susceptible to the loss of lean body mass and its attendant increased morbidity and mortality caused by an intrinsic lack of endogenous stores and greater baseline requirements. An appropriately designed mixed fuel system of nutritional support replete in protein does not quell this metabolic response but can result in anabolism and continued growth in ill children. In addition, the use of adequate analgesia and anesthesia is a readily available and proven means of reducing the magnitude of the catabolism associated with operation and injury. Finally, as hormonal- and cytokine-mediated metabolic alterations are better understood, therapeutic interventions may become available to directly modulate the metabolic response to illness, thus potentially further improving clinical outcome in pediatric surgical patients.
Single-phase and two-phase flow pressure drop in the vertical header of microchannel heat exchanger.

Refrigerant maldistribution among parallel microchannel tubes deteriorates the performance of microchannel heat exchanger because it creates unwanted superheated region that has lower heat transfer. Besides phase separation in the header, the pressure drop in the header causes the pressure drop in the microchannel tube to be different between each tube, also resulting in flow rate maldistribution. This paper experimentally investigates the pressure drop of single-phase and two-phase flow in the vertical header of a multi-pass microchannel heat exchanger. The overall pressure drop in the header includes four components: acceleration, gravitation, friction, and minor pressure drop due to microchannel tube protrusion. The gravitation and minor pressure drops are dominant for single-phase liquid flow and at low qualities of two-phase flow, whereas the acceleration and minor pressure drops are dominant for single-phase vapor flow and at high qualities of two-phase flow. The model to predict the overall pressure drop in the header for single-phase and two-phase flow is proposed based on the experimental results.
Inattentional Blindness in a Simulated Driving Task

This study was a subset of a larger investigation on the role of task load on IB occurrences in the context of driving. The focus of this study was the relationship between mental demand and inattentional blindness (IB) occurrences for a critical stimulus that is directly relevant to primary task performance. Forty-four undergraduates followed a series of auditory directives in a simulated driving environment to reach a destination. The final directive instructed participants to turn left at an intersection clearly marked with a “no left turn” sign. Of the total number of participants in this study, 79.5% (35 of 44) failed to detect the “no-left turn” road sign critical stimulus. Results revealed that individuals who detected the “no left turn” sign had significantly higher scores on the mental demand component of the NASA-TLX compared to those who failed to detect the sign. The negative relationship between IB occurrences and the subjective mental demand ratings suggest another factor, such as task engag...
T helper cell dysfunction in systemic lupus erythematosus (SLE): relation to disease activity.

Patients with systemic lupus erythematosus (SLE) are known to have defects in both humoral and cellular immunity. The significance of defective T cell-mediated immunity and its relationship to disease activity have not been clearly established. We studiedin vitro T helper cell (Th) function in 150 SLE outpatients and correlated Th function with validated measures of disease activity. Interleukin 2 (IL-2) production by peripheral blood mononuclear cells (PBMC) was measured after stimulation with the recall antigens influenza A virus (FLU) and tetanus toxoid (TET), irradiated allogeneic peripheral blood mononuclear cells (ALLO), and phytohemagglutinin (PHA). We observed three patterns of Th response: (1) 76 of 150 (50%) of patients responded to the recall antigens FLU and/or TET, ALLO, and PHA; (2) 62 of 150 (42%) of patients did not respond to recall antigens but responded to ALLO and PHA; and (3) 12 of 150 (8%) of patients did not respond to either recall antigens or ALLO antigens. This diminished T cell function was correlated with higher disease activity as measured by four scales of clinical activity, such that individuals who exhibited morein vitro immune dysfunction presented with significant increases in their clinical activity indicies. The alterations in T cell function could not be accounted for by medication doses alone. Thus, SLE patients have multiple distinct defects at the level of the Th cell which are associated with clinical measures of disease activity.
Enriching newlyweds: An evaluation of three enrichment programs

Abstract Three marital enrichment programs were evaluated to determine their effectiveness with a newlywed population. Seventy-one couples were divided among three groups, and 28 couples were assigned to a control group. Results were mixed when treatment groups were combined and compared to the control group. While t-tests using change scores demonstrated significant differences on some important variables, analyses using ANCOVA demonstrated no change. Comparisons among the three programs suggested that none was clearly superior. Treatment couples reported very high levels of satisfaction with their participation in the programs, and almost all couples (98%) indicated they would recommend the programs to other newlywed couples.
Photosynthetic gene expression in black willow under various soil moisture regimes

This study was the first attempt to extract RNA from black willow (Salix nigra Marshall) that contains numerous secondary products and to examine the photosynthetic gene expression of black willow under a wide range of soil moisture regimes. Black willow cuttings were grown under control, continuous flooding, periodic flooding and periodic drought for 42 d. A modified lithium chloride precipitation method was used for RNA extraction. Results of real-time polymerase chain reaction showed reduced gene expression of oxygen evolving complex, large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenasse and ferredoxin on day 7 as well as the latter two on day 14 in response to flooding. Therefore, decreased expression of these three genes may have contributed to the observed reduced photosynthetic capacity in response to flooding.
Selection and identification of ligand peptides targeting a model of castrate-resistant osteogenic prostate cancer and their receptors.

We performed combinatorial peptide library screening in vivo on a novel human prostate cancer xenograft that is androgen-independent and induces a robust osteoblastic reaction in bonelike matrix and soft tissue. We found two peptides, PKRGFQD and SNTRVAP, which were enriched in the tumors, targeted the cell surface of androgen-independent prostate cancer cells in vitro, and homed to androgen receptor-null prostate cancer in vivo. Purification of tumor homogenates by affinity chromatography on these peptides and subsequent mass spectrometry revealed a receptor for the peptide PKRGFQD, α-2-macroglobulin, and for SNTRVAP, 78-kDa glucose-regulated protein (GRP78). These results indicate that GRP78 and α-2-macroglobulin are highly active in osteoblastic, androgen-independent prostate cancer in vivo. These previously unidentified ligand–receptor systems should be considered for targeted drug development against human metastatic androgen-independent prostate cancer.
Origins of Pulsing Regime in Cocurrent Packed-Bed Flows

The mechanism of the formation for cocurrent downflow pulse flow was studied experimentally in a packed bed of inert spheres of 3, 6, and 8 mm using an air−water flow. By measurement of the flow distance until pulses are observed, the spatial growth rate of convective disturbances within the pulsing flow regime were determined. Observations indicate that pulses form from trickling flow as the result of a global convective instability. Further, experiments indicate that an analogous transition exists for the formation of pulses from the dispersed bubble flow regime, except that pulses form as the flow rates are adjusted to become less severe. Existing global instability models based on averaged (dispersed flow) momentum equations were modified to explain experimental results. A key uncertainty in modeling pulse formation from trickle flow is the regularization (i.e., stabilization) force. Re-examination of this issue suggests some mechanistic inconsistencies with surface tension which had been used in prev...
On the zero shift problem of a vertical pendulum

The effect of the vibration transmitted through pendulum support on the accuracy of a pendulum used as a vertical reference is examined. Based upon the method of equivalent linearization of Kryloff and Bogoliuboff together with a perturbation scheme, the average angular displacement of a vertical pendulum is obtained in terms of the functional averages involving support excitations. It is shown that the method leads to general and simple formulas for estimating the zero shift and, in the case of random support excitations, second-moment properties. The analysis is valid for both heavily damped and weakly damped systems. The zero shifts due to several types of deterministic and random excitations are computed. Methods of minimizing the zero shift are considered for these cases.
Leadership decision making and the use of data

Intelligence gathering, or data collection, is a preliminary and critical stage of decision making. Two key approaches to intelligence gathering are “discovery” and “idea imposition.” The discovery approach allows us to learn about possibilities by gathering intelligence in order to identify and weigh options. The idea imposition approach limits intelligence gathering and focuses resources on promoting a solution. The purpose of this study is to explore the intelligence-gathering stage of organizational leaders during decision making from both of these perspectives and to begin to identify themes as they relate to the data considered, types of decisions and outcomes sought, and level of confidence in decision-making success.
Scalable Webcam Eye Tracking by Learning from User Interactions

Eye tracking systems are commonly used in a variety of research domains, but cost thousands of dollars. In my thesis I investigate a new approach to enable eye tracking for common webcams. The aim is to provide a natural experience to everyday users that are not restricted to laboratories and highly controlled studies. The accuracy of eye tracking webcams will be improved by user interactions which continuously calibrate the eye tracker during regular usage. Eye tracking can become a reality for many potential applications such as large-scale naturalistic user studies, online gaming, or enabling people to perform hands-free navigation of websites.
Sums of perturbed sequences of integers

Abstract An increasing sequence of nonnegative integers A is an asymptotic basis or a subbasis of order h if the sequence A + A + … + A (h summands) contains all sufficiently large integers or contains an infinite artihmetic progression, respectively. Such basis properties of a sequence A may be affected by small perturbations of the elements of A. The stability of these basis properties under small perturbations is examined in a general setting as well as for the specific sequence of the primes. The relation of the latter case to the Goldbach conjecture is noted.
Leadership development: The current state and future expectations.

This article discusses the common themes in this special issue of Consulting Psychology Journal on “Leadership Development” and summarizes some of the current issues in leadership development. A particular focus is on using an integrated model or framework to guide leadership development efforts. Em
Dynamic trees as search trees via Euler tours, applied to the network simplex algorithm

Thedynamic tree is an abstract data type that allows the maintenance of a collection of trees subject to joining by adding edges (linking) and splitting by deleting edges (cutting), while at the same time allowing reporting of certain combinations of vertex or edge values. For many applications of dynamic trees, values must be combined along paths. For other applications, values must be combined over entire trees. For the latter situation, an idea used originally in parallel graph algorithms, to represent trees by Euler tours, leads to a simple implementation with a time of O(logn) per tree operation, wheren is the number of tree vertices. We apply this representation to the implementation of two versions of the network simplex algorithm, resulting in a time of O(logn) per pivot, wheren is the number of vertices in the problem network.
Structure of the chloroplast signal recognition particle (SRP) receptor: domain arrangement modulates SRP-receptor interaction.

The signal recognition particle (SRP) pathway mediates co-translational targeting of nascent proteins to membranes. Chloroplast SRP is unique in that it does not contain the otherwise universally conserved SRP RNA, which accelerates the association between the SRP guanosine-5′-triphosphate (GTP) binding protein and its receptor FtsY in classical SRP pathways. Recently, we showed that the SRP and SRP receptor (SR) GTPases from chloroplast (cpSRP54 and cpFtsY, respectively) can interact with one another 400-fold more efficiently than their bacterial homologues, thus providing an explanation as to why this novel chloroplast SRP pathway bypasses the requirement for the SRP RNA. Here we report the crystal structure of cpFtsY from Arabidopsis thaliana at 2.0 A resolution. In this chloroplast SR, the N-terminal “N” domain is more tightly packed, and a more extensive interaction surface is formed between the GTPase “G” domain and the N domain than was previously observed in many of its bacterial homologues. As a result, the overall conformation of apo-cpFtsY is closer to that found in the bacterial SRP•FtsY complex than in free bacterial FtsY, especially with regard to the relative orientation of the N and G domains. In contrast, active-site residues in the G domain are mispositioned, explaining the low basal GTP binding and hydrolysis activity of free cpFtsY. This structure emphasizes proper N–G domain arrangement as a key factor in modulating the efficiency of SRP–receptor interaction and helps account, in part, for the faster kinetics at which the chloroplast SR interacts with its binding partner in the absence of an SRP RNA.
Synthesis and Polymerization Behavior of Tridentate Diacetylene Hosts

The synthesis of three new tridentate ligands capable of forming large cavities for encapsulation of organoiodides is described. Each compound consists of a central heterocyclic “base unit” linked by acetylenes to two heterocyclic “arm” units. The base and the arm unit are each either a 2,6-disubstituted pyridine or a 2,5-disubsituted thiophene ring. The terminal end of each arm unit is connected to a (butoxycarbonyl)methylurethanyl (BCMU) moiety by way of a diacetylene linkage. This serves as a polymerogenic group that helps align the diacetylenes for topotactic polymerization. The triaryl ring systems are constructed through a series of aryl bromide/protected acetylene coupling steps, followed by deprotection and further coupling. Two of the compounds polymerize photochemically and all three polymerize thermally.
REVIEW OF SLUSH HYDROGEN PRODUCTION AND UTILIZATION TECHNOLOGIES

Slush hydrogen is a mixture of liquid and frozen hydrogen in equilibrium with the gas at the triple point. Slush hydrogen is expected to be the primary propellant for the National Aero-Space Plane (NASP) because of its potential for reducing the plane's size and significantly cutting the projected gross lift-off weight. This paper provides an overview of slush hydrogen production methods and reviews the current state of knowledge regarding slush hydrogen utilization.
Trends in medical error education: are we failing our residents?

Abstract Background The Institute of Medicine has called for physician education as a key step in medical error prevention. In our 2002 national survey, pediatric resident education about medical error prevention was sporadic. We sought to describe the amount and type of pediatric resident training about medical errors and to assess the change in training since 2002. Methods We surveyed a national sample of 50 pediatric chief residents randomly selected from the 198 Accreditation Council for Graduate Medical Education–accredited residency programs from August to November 2010. The 31-item telephone survey was developed from the 2002 survey, with the addition of 10 items about electronic learning and resident quality improvement projects. The survey included 4 domains: current patient safety curriculum, chief resident knowledge, learning from medical errors, and demographics. Results We phoned 55 chief residents and contacted 51. Fifty participated (90% participation rate). Ninety-four percent of chief residents stated that their program had a formalized curriculum to discuss medical errors, compared to only 50% ( P Conclusions Although resident education about medical errors has improved since 2002, opportunities to model learning from mistakes are frequently missed.
The neutral kaon program at Fermilab and recent E731 results

Currently, Fermilab has a long-range program in neutral kaon physics which covers a wide variety of physics topics. In this report, I will be discussing the latest results from experiment E731 on the radiative decay of neutral kaons KL1S → π+π−γ. These results include the first measurement of two new CP violation parameters: η+−γ = (2.60 ± 0.54 ± 0.21) · 10−3 and φ+−γ = (41 ± 28 ± 11)0. The presence of a rho propagator form factor in the KL direct emission decay has been confirmed. Besides these results, the status of experiments E773 and E799, which are running in the 1991 fixed target run at Fermilab, and plans for future neutral kaon experiments will be discussed.
Internal Jugular Phlebectasia in Menkes Disease

Pediatric neck masses should trigger a high index of suspicion for certain genetic disorders of connective tissue. To highlight this, we report on three infants with Menkes disease, an inherited disorder of copper transport, who developed large, unilateral neck masses at between 7 and 17 months of age. All were identified in imaging studies as internal jugular phlebectasia. The masses, which enlarged on crying or exertion, have remained clinically benign in these patients for 20, 17, and 2 months, respectively. While arterial tortuosity and aneurysms have been reported often in Menkes disease, venous phlebectasia has rarely been described. We speculate that low activity of the copper-dependent enzyme, lysyl oxidase, leading to reduced tensile strength in the deep cervical fascia comprising the carotid sheath may predispose to internal jugular phlebectasia in these individuals. Improved survival and neurological outcomes in infants with Menkes disease due to advances in early diagnosis and treatment may be associated with recognition of novel clinical stigmata of this condition such as internal jugular phlebectasia.
Sonochemical Synthesis of a Poly(methylsilane), a Precursor for Near-Stoichiometric SiC

We report a sonochemical process for a single-pot synthesis of high molecular weight poly(methylsilane) (PMS) of composition [(CH 3 SiH) x (CH 3 Si) y (CH 3 SiH 2 1 z ] n , where x + y + z = 1 and 0.65 ≥ (x + z) ≥ 0.23 by the sodium polycondensation reaction of CH 3 SiHCl 2 in a solvent mixture of hexane or toluene and tetrahydrofuran (THF) using ultrasonic activation (47 kHz, 130 W). This polycondensation reaction takes place in two stages: (1) 10-25 h of reaction in which an oligo(methylsilane) (OMS) oil (0.91 ≥ (x + z) ≥ 0.83) is obtained that gives low ceramic residue yields of silicon-rich SiC on pyrolysis in argon and (2) 25-40 h of reaction during which is obtained a PMS solid that gives high ceramic residue yields of near stoichiometric SiC on pyrolysis. PMS also may be prepared by branching of the oligo(methylsilane) with sodium and ultrasonication for ∼5 h in a toluene and THF solvent mixture. PMS is soluble in hexane and toluene and its pyrolysis in argon gives a ceramic residue yield up to 90%. In addition to the main product of the condensation reaction, a high molecular weight PMS may be extracted from large NaCl crystals (the other product of the CH 3 SiHCl 2 /Na reaction). A comparison of sonochemical and conventional (reflux) activation also is provided. Ceramic fibers, films, and solid monoliths were prepared from PMS without requiring a curing step.
Synthesis and characterization of a novel, fluoride-releasing dimethacrylate monomer and its dental composite

A novel, fluoride-releasing dimethacrylate monomer containing zirconium fluoride chelate for use in dental composites was synthesized by an efficient four-step procedure starting from 4,4-bis-(4-hydroxyphenyl)-pentanoic acid and was characterized by electrospray mass spectrometry, Fourier transform infrared (FTIR), and 1H and 13C NMR spectroscopies. The synthesized monomer was photopolymerized with camphorquinone and 1-phenyl-1,2-propane-dione as initiators and N,N-dimethylaminoethyl methacrylate as an accelerator. The photopolymerization process was investigated by FTIR spectroscopy. The experimental composite containing 13.7 wt % of the synthesized monomer was tested for fluoride release, fluoride recharge, compressive strength, and flexure strength, each in comparison to three commercial flowable dental composites. The results showed that the experimental composite had significantly higher fluoride release and fluoride recharge capabilities than the commercial flowable composites. The flexure strength was comparable to the commercial materials. The water sorption and solubility met the requirements of the International Organization for Standardization 4049 and the American National Standards Institute/American Dental Association Specification Number 27. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 985–998, 2004
Solvent-free lipid bimolecular membranes of large surface area

The formation of a solvent-free lipid bimolecular membrane of large surface area (approx. 2 mm2) by the successive transfer of two monolayers upon an aperature of a closed chamber has been demonstrated. The electrical parameters of the membrane appear to be similar to the conventional Montal-Mueller solvent-free membrane. The use of a closed chamber greatly increases the stability of the membrane to mechanical disturbances and produces hydrostatic equilibrium necessary for electrical measurements.
Video-server designs for supporting very large numbers of concurrent users

We present a design for a video server in which video content is stored in special video-delivery subsystems attached directly to network components such as switches or high-speed-network ports rather than the magnetic disk storage attached to conventional computer systems. Video is preformatted and stored in the form of network packets. This design approach overcomes the CPU- and I/O-bandwidth limitations of conventional computers in executing the file-system and network-protocol code for many concurrent video streams, resulting in higher performance at a lower cost. Two designs for the approach are discussed. The first extends the packet buffer of a shared-buffer switch with additional memory for storing the video packets. The second design uses a stream controller as the interface between an array of disks and a traditional switch or network port. We have built a prototype based on the second design. To avoid interference on the disks, data is interleaved across all disks connected to a stream controller in units of fixed playback time. This also reduces the jitter in the response time of the disks and, therefore, the size of the buffers needed to maintain interruption-free delivery. The cost benefits of both approaches are discussed.
Diabetes, hypertension and erythrocyte aggregation in acute stroke

Elevated erythrocyte (RBC) aggregation (RBC-A) may contribute to the pathogenesis of stroke and stroke recurrence. We measured RBC-A at low shear in 55 patients with acute ischemic stroke and in 24 ag
The Continuum Limit of the Infinite Isotropic Heisenberg Chain in Its Ground State Representation

Abstract The Hamiltonian of the infinite spin- 1 2 isotropic Heisenberg chain with lattice spacing ϵ and nearest-neighbor interaction, corresponding to a ground state representation of the quasilocal algebra, acts on a Hilbert space that can be naturally embedded in a continuum Fock space. It is proved that as ϵ → 0 this Hamiltonian converges on the latter space in the strong resolvent sense to a Hamiltonian describing a gas of free non-relativistic equal mass bosons. It is also shown that the projection on the spin wave sectors containing bound magnons strongly converges to zero as ϵ → 0, even though the bound magnon energies converge as ϵ → 0.
The trouble with networks: Managing the scots' early-modern madeira trade

Most studies of the early-modern Atlantic world give its emergence a sense of inevitability. Historians who have tried to understand networks in the early-modern Atlantic have focused solely on their successes, which skews our understanding. This analysis of the role played by Scottish networks in the production, distribution, and consumption of Madeira wine during that product's golden age, which lasted from 1640 to 1815, attempts to correct the record. Networks succeeded when they led to profitable sharing of information, goods, and services, and they failed when individuals were unable to get networks to function for them. Problems arose among the parties in the course of negotiating terms for sharing, monitoring the agreements, responding to disasters, and estimating the costs of transactions. At times, networks worked so well that they metamorphosed into other social and commercial forms, helping to establish critical nonmetropolitan links within and between the British and Portuguese empires.
2009 Special Issue: Neural networks with multiple general neuron models: A hybrid computational intelligence approach using Genetic Programming

Classical neural networks are composed of neurons whose nature is determined by a certain function (the neuron model), usually pre-specified. In this paper, a type of neural network (NN-GP) is presented in which: (i) each neuron may have its own neuron model in the form of a general function, (ii) any layout (i.e network interconnection) is possible, and (iii) no bias nodes or weights are associated to the connections, neurons or layers. The general functions associated to a neuron are learned by searching a function space. They are not provided a priori, but are rather built as part of an Evolutionary Computation process based on Genetic Programming. The resulting network solutions are evaluated based on a fitness measure, which may, for example, be based on classification or regression errors. Two real-world examples are presented to illustrate the promising behaviour on classification problems via construction of a low-dimensional representation of a high-dimensional parameter space associated to the set of all network solutions.
Synthesis, characterization and evaluation of urethane derivatives of Bis-GMA

Objectives. The aims of the study were to synthesize derivatives of Bis-GMA having pendant n-alkyl urethane substituents and to characterize and evaluate their physicochemical properties. Methods. Stoichiometric amounts of Bis-GMA and n-alkyl isocyanates were reacted in dichloromethane with dibutyltin dilaurate as a catalyst. Volumetric shrinkage, water uptake, degree of vinyl conversion, refractive index and viscosity of resulting urethane monomers and those of Bis-GMA were measured. The flexural strengths of their corresponding homopolymers and that of Bis-GMA were also measured. Results. These types of urethane derivatives of Bis-GMA exhibited lower viscosities and were more hydrophobic than Bis-GMA. Generally, the viscosity of these experimental monomers decreased with increasing chain length of the alkyl urethane substituent. Photopolymerization of the new monomers gave high degrees of vinyl conversion compared to Bis-GMA. The experimental monomers also yielded polymers with lower polymerization shrinkages at equivalent degrees of vinyl conversion, than Bis-GMA. The refractive indices of these urethane derivatives were similar to Bis-GMA, but the flexural strengths of their polymers were lower than that of the Bis-GMA homopolymer, decreasing with increasing chain length of the alkyl urethane substituent. Significance. Because of their excellent overall properties, these new derivatives of Bis-GMA have potential as dental monomers that can improve many properties of resin based dental materials that utilize methacrylate monomer systems.
Further misconceptions about species recognition: a reply to Padian and Horner

In their response to our recent article in TREE [1], Padian and Horner [2] reiterate our point that the concept of ‘species recognition’ is rife with confusion. Indeed, confusion regarding this concept is precisely what motivated our paper. Of the many specific points of confusion that could be discussed, Padian and Horner [2] home in on the question of whether mate recognition is a subset of species recognition or, vice versa, whether species recognition is a subset of mate recognition. Padian and Horner [2] advocate the former; Andersson [3] supports the latter.
Density of states, entropy, and the superconducting Pomeranchuk effect in Pauli-limited Al films

We present low-temperature tunneling density of states measurements of Pauli-limited Al films in which the Zeeman and orbital contributions to the critical field are comparable. We show that films in the thickness range of $6\char21{}7\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ exhibit a reentrant parallel critical field transition which is associated with a high-entropy superconducting phase, similar to the high-entropy solid phase of $^{3}\mathrm{He}$ responsible for the Pomeranchuk effect. This phase is characterized by an excess of states near the Fermi energy so long as the parallel critical field transition remains second order. Theoretical fits to the zero-bias tunneling conductance are in good agreement with the data well below the transition but theory deviates significantly near the transition. The discrepancy is a consequence of the emergence of $e\text{\ensuremath{-}}e$ interaction correlations as one enters the normal state.
Numerical study of a low permeability microporous heat sink for cooling phased-array radar systems

Abstract Microporous media is being used to develop an improved forced convection cold plate device for removing waste heat from high frequency phased-array radar apertures. The waste heat, generated by transmit and receive microwave functions mounted in separate electronic modules, is conducted to the surfaces of a thin rectangular enclosure (cold plate) through which coolant flows. The performance of the phased-array radar is known to deteriorate very rapidly when the difference in operating temperatures of identical electronic components within each module increases. The cold plate device investigated here, designed to minimize this temperature difference, consists of a microporous layer placed (brazed) within the cold plate. A theoretical transport model is developed around an extended system of two-dimensional equations obtained by considering a thin enclosure and integrating the original three-dimensional equations along the direction of smaller dimension. Thermo/hydraulic characteristics are obtained through numerical simulations considering a low permeability aluminum alloy porous layer, and air, water and PAO as coolants. A theoretical estimate of the global pressure drop across the cold plate is also obtained and compared with the numerical results. The microporous cold plate provides substantially more uniform operating temperature for identical components in all module housings than a cold plate without porous layer. Results also suggest an increased global heat transfer coefficient reducing the operational (junction) temperature of the electronics for the same waste heat.
Lack of association between carcinoma of the breast and HL-A specificities.

Forty-eight patients with carcinoma of the breast and 122 controls from the Boston area were typed for 24 HL–A specificities. Types were assigned objectively by a computer program, and two controls were matched to each of 40 breast cancer patients on the basis of the countries of origin of the patients’ ancestors or race. Our data fail to confirm an association of HL–A7 with breast cancer suggested by the data of Patel and coworkers (1972) who typed 52 patients from the Boston area. In the present study, no HL–A specificity or pairs of specificities were found to be significantly more or less frequent in breast cancer patients than in controls.
Mass transfer by advection and diffusion from a drug-eluting stent

Abstract Stents are often used to maintain the diameter of the coronary artery lumen. The insertion of a stent into an artery often results in the accumulation of scar tissue in response to the stent’s presence. Drug-eluting stents dispense a drug designed to limit the growth of such scar tissue, thus reducing the likelihood of restenosis. The trajectory of the eluted drug is of critical clinical importance. The bifurcation of the drug between the artery tissue and the blood-carrying lumen is a highly relevant issue to the success of stenting. Prior simulations of this issue have dealt with highly specific situations. Here, the problem is nondimensionalized in order to obtain universal solutions. The results, in terms of the Sherwood number, are reported in terms of the Reynolds and Schmidt numbers, and a mass-transfer version of the Biot number. It was found that the highest rates of mass transfer occurred at the forwardmost portion of the stent. The rate of drug delivery to the lumen was greater than that to the artery tissue.
HARP: a dynamic spectral partitioner

Partitioning unstructured graphs is central to the parallel solution of computational science and engineering problems. Spectral partitioners, such as recursive spectral bisection (RSB), have proven effective in generating high-quality partitions of realistically sized meshes. The major problem which hindered their widespread use was their long execution times. This paper presents a new inertial spectral partitioner called HARP. The main objective of the proposed approach is to quickly partition the meshes at runtime for the dynamic load balancing framework JOVE which dynamically balances the computational loads of distributed-memory machines with a global view. The underlying principle of HARP is to find the eigenvectors of the unpartitioned vertices and then project them onto the eigenvectors of the original mesh. Results for various meshes ranging in size from 1000 to 100,000 vertices indicate that HARP can indeed partition meshes rapidly at runtime. Experimental results show that our largest mesh can be partitioned sequentially in only a few seconds on an SP-2, which is several times faster than other spectral partitioners, while maintaining the solution quality of the proven RSB method. These results indicate that graph partitioning can now be truly embedded in dynamically changing real-world applications.