cssi/SciSciGPT-SciSciNet huggingface dataset:
Transport of biological molecules in surfactant–alginate composite hydrogels

Abstract Obstructed transport of biological molecules can result in improper release of pharmaceuticals or biologics from biomedical devices. Recent studies have shown that nonionic surfactants, such as Pluronic® F68 (F68), positively alter biomaterial properties such as mesh size and microcapsule diameter. To further understand the effect of F68 (incorporated at concentrations well above the critical micelle concentration (CMC)) in traditional biomaterials, the transport properties of BSA and riboflavin were investigated in F68–alginate composite hydrogels, formed by both internal and external cross-linking with divalent cations. Results indicate that small molecule transport (represented by riboflavin) was not significantly hindered by F68 in homogeneously (internally) cross-linked hydrogels (up to an 11% decrease in loading capacity and 14% increase in effective diffusion coefficient, Deff), while protein transport in homogeneously cross-linked hydrogels (represented by BSA) was significantly affected (up to a 43% decrease in loading capacity and 40% increase in Deff). For inhomogeneously cross-linked hydrogels (externally cross-linked by CaCl2 or BaCl2), the Deff increased up to 50 and 83% for small molecules and proteins, respectively. Variation in the alginate gelation method was shown to affect transport through measurable changes in swelling ratio (30% decrease) and observable changes in cross-linking structure as well as up to a 3.6- and 11.8-fold difference in Deff for riboflavin and BSA, respectively. Aside from the expected significant changes due to the cross-linking method utilized, protein transport properties were altered due to mesh size restrictions (10–25 nm estimated by mechanical properties) and BSA–F68 interaction (DLS). Taken as a whole, these results show that incorporation of a nonionic surfactant at concentrations above the CMC can affect device functionality by impeding the transport of large biological molecules.
First-Order Partial Differential Equations

In this chapter we study the solution of first-order partial differential equations of the form
Organization of genetic variation at the molecular level: lessons from Drosophila.

The allelic variation in DNA revealed by molecular methods has become a panacea for resolving questions about the evolutionary history and structure of natural populations. The problem we are interested in considering here involves the use of sequence variation for making inferences about the past history of a population: the extent of population subdivision, the level of gene flow, the historical patterns of population movement, the origins or genealogy of particular races or subpopulations, or the phylogenetic relationships among groups. In order to answer historically contingent questions such as these with molecular variation, it is necessary to interpret the patterning of that variation in terms of population-level forces rather than in terms of specific forces acting at or near the locus. What assumptions about the way in which DNA is evolving allow such an interpretation? And what is known about their validity?
Board certification among preventive medicine residency graduates: characteristics, advantages, and barriers.

In 1991, a mail survey was conducted of graduates (1979–1989) of general preventive medicine/public health (GPM/PH) residency programs to obtain information about the graduates’ demographic characteristics, training, and present professional work. Specifically, we evaluated the survey data for percentage of graduates with board certification, advantages of board certification, and barriers to board certification in preventive medicine (PM). The survey response rate was 74% (797 of 1,070 graduates). Only 45% of the respondents were board certified in PM as of 1991. The percentage of respondents board certified in PM was highest among military PM residency graduates and lowest among those from the Centers for Disease Control (CDC) PM residency. Reasons for not taking the board examination included the perception of limited benefit of board certification in current employment or professional endeavors, previous board certification in a clinical specialty, lack of a master of public health (MPH) degree, high cost and time commitment for the examination, and uncertainty about examination admission requirements. PM residency graduates with board certification in PM were more likely to be involved in public health and preventive medicine programs, devoted more time to administration and management, and earned more income than those PM residency graduates without PM board certification. Increasing the percentage of residency graduates who pursue PM board certification will require increasing the advantages of certification for practice, encouraging all residents to identify themselves as practicing the specialty of PM, and addressing the unique concerns of physicians who train both in PM and in a purely or primarily clinical specialty. [Am J Prev Med 1994:10:251–8]
Novel Control Approach for Modular Multilevel Converter Based on $\alpha \beta 0$ Reference Frame Without PLL

Modular multilevel converter (MMC) has become the basic building block for multi-terminal direct current (MT-DC) system and dc grids. To effectively control the power flow of the ac-dc MMC systems, the dual-loop power decoupling control based on $dq$ reference frame is employed, which needs accurate phase information of ac grid through phase-locked loop (PLL). However, the control system may fail due to unstable PLL. In this paper, a novel power flow control approach based on $\alpha\beta 0$ reference frame without PLL is proposed, which consists of an inner loop for power decoupling and an outer loop for tracking power reference. Nonlinear state feedback is employed to eliminate time-varying and nonlinear terms through full-state linearization for constructing the inner loop. PI controller and feedforward compensation are used to build classical second-order damping elements for keeping fast dynamic response and tracking power reference in the outer loop. Performance of the proposed grid-connected control strategy for an high voltage MMC station is evaluated based on simulation studies in the PSCAD/EMTDC software environment. The study results illustrate the effectiveness of the proposed strategy for controlling the grid-connected MMC.
iFixit With the Library: Partnering for Open Pedagogy in Technical Writing

This article describes how a technical writing instructor adopted an open textbook from the Dozuki repair company and an accompanying open pedagogy project through iFixit, for which students wrote openly-licensed repair articles. His work was supported and amplified by the Linn-Benton Community College’s Textbook Affordability Steering Committee and the library. Open pedagogy provides many opportunities for instructor-librarian collaboration. In this case, the library was able to provide information literacy support on intellectual property to the class and help the instructor promote the project across campus and beyond.
An extensive review of laboratory scaled experimental setups for studying drill string vibrations and the way forward

Abstract Minimizing drill string vibrations is crucial in optimizing drilling efficiency. While many theoretical models exist to understand and investigate vibration modes, the need for experimental validation is both necessary and insightful. This paper presents a comprehensive review and extensively compares the existing downscaled laboratory test rigs to propose a standardized approach to the experimental design. This includes the need for proper downscaling factor, rock-bit interaction methods as well as appropriate component and material selection. The downscaling factor for the test rigs is also compared to examine the accuracy of the existing experimental setups in mimicking actual drilling vibrations, more importantly, torsional vibrations and stick slip phenomenon. Altogether, an updated experimental setup is proposed that takes into account the above-mentioned design recommendations. A novel and predictable method of introducing rock-bit interaction is introduced through hexapod robots. Finally, combined with advanced data handling capacity, the experimental setup aims to provide a good reference point for downscaled vibration data and future design criteria.
The Information and Communication Technologies (ICT) in Leadership—Case of Lebanese Public Sector

The management is both a product and a process of and in its environment. The managerial thought is evolving and developing to adapt itself with new challenges both cultural and technological to meet different needs of the company. Today, the leader is characterized by his capacity to be in interaction with his environment to serve it better. Through a qualitative study and based on seven interviews conducted with superior person in charge of the Lebanese Public Sector, this article searches to analyze how the role of the leaders of public sector evolves in view of technological transformations resulting from the adoption and the diffusion of information and communication technologies (ICT) in their institutions. To face these new technological challenges, the person in charge of the public sector must exceed his role of a traditional manager to the role of a transformational leader. Hence the necessity of an adaptation, and a mutation in the organizational structure to give an intermediary role to the computer scientists specialist of data and information in the public institutions.
Chapter 11 – Long-Range Membrane Properties

Chapter 11 will discuss a few large-scale membrane properties including membrane lipid packing, membrane protein distribution, membrane lipid microdomains, and finally a process that keeps all of the various membrane properties in synch, homeoviscous adaptation (HVA).
A Securities Tax and the Problems of Taxing Global Capital

An earlier paper, How to Tax Capital, 70 Tax L. Rev. 1 (2016), proposed a new approach to taxing capital owned by U.S. households and nonprofits. The cornerstone is a flat periodic tax on the market value of U.S. publicly traded securities. An annual tax rate of around .8 percent (80 basis points) would roughly approximate the average tax burden on capital income in the U.S. under the existing patchwork system for taxing capital income. A security issuer would remit the tax based on the market value of its securities. A security issuer would receive a credit for U.S. publicly traded securities it holds so that wealth that is represented by a string of publicly traded securities would be taxed once. Wealth held in forms other than publicly traded securities (e.g, private equity and closely held companies) would be taxed by a complementary tax at the same rate on their estimated value. The earlier paper explained why the securities tax is superior to the individual income tax and the corporate income tax as a tax on capital. It eliminates most distortions created by the existing system, it is easy to administer, and it is impossible to evade other than by holding wealth in illiquid forms (which is costly). This paper examines how the securities tax would function in a global context assuming that other nations do not change their approach to taxing cross-border investment. The current system involves a bifurcated tax on capital income with the nation in which capital is used imposing a company-level tax on income and the state in which owners of capital reside imposing an owner-level tax of dividends, interest, and capital gains. The securities tax is a unitary tax on capital imposed at the company level. Integrating a unitary tax with the current bifurcated system requires several modifications in the securities tax: the corporate income tax would need to be retained to tax foreign direct investment in the U.S.; the U.S. would probably want to give a U.S. company a partial credit against the securities tax for foreign taxes paid by a company on foreign source income; and the U.S. probably would want to rebate a significant part of the securities tax to identified foreign owners of U.S. securities (the rebate would not be paid to unidentified owners). These modifications would mean that the securities tax would not remedy the problems that currently plague the taxation of global capital. One modest benefit is that not rebating the tax to unidentified foreign owners of U.S. assets would allow the U.S. government to share in the profit from the U.S. serving as a haven for hidden wealth, which would make the U.S. somewhat less attractive as a haven. But the modified securities tax would be no worse than the status quo with respect to taxing cross border investment.
Fibroepithelial Lesions With Cellular Stroma on Breast Core Needle Biopsy

Fibroepithelial lesions with cellular stroma (FELCS) in breast core needle biopsy (CNB) specimens may result in either fibroadenoma or phyllodes tumor at excision. We evaluated histologic features, proliferation indices (by Ki-67 and topoisomerase II α immunostaining) and p53 expression in 29 cases of FELCS in CNB specimens and correlated these with excision findings in a blinded manner. On excision, 16 patients had fibroadenomas and 12 had phyllodes tumors. All CNB specimens with mildly increased stromal cellularity were fibroadenomas on excision (n = 4), and all with markedly cellular stroma were phyllodes tumors (n = 4). Among CNB specimens with moderate cellularity (12 fibroadenomas and 8 phyllodes tumors), only stromal mitoses were discriminatory histologically. Stromal proliferation indices were significantly higher in CNB that were phyllodes tumors vs fibroadenomas. Assessment of stromal cellularity, mitoses, and proliferation indices might help determine the probability of phyllodes tumor occurring and guide management of these cases.
Cancer therapeutic monoclonal antibodies targeting lymphocyte co-stimulatory pathways.

Abstract Monoclonal antibody (mAb) targeting to tumor antigen is an important therapeutic approach for the treatment of a variety of cancers. Both positive and negative co-stimulatory pathways are critical components for the control and fine-tuning fo immune responses and recently mAb targeting of lymphocyte co-stimulatory pathways has been investigated. With the development of agonistic and antagonistic mAbs, both positive and negative pathways can be regulated and the potent therapeutic efficacy of this method has been demonstrated in experimental models. With high affinity and selectivity, as well as humanization technology for mAbs, there is little doubt that this new approach alone, or in combination with other therapeutic modalities, will play an important role in immunotherapy for cancers in the near future.
Causes and consequences of micronuclei.

Abstract Micronuclei are small membrane-bounded compartments with a DNA content encapsulated by a nuclear envelope and spatially separated from the primary nucleus. Micronuclei have long been linked to chromosome instability, genome rearrangements, and mutagenesis. They are frequently found in cancers, during senescence, and after genotoxic stress. Compromised integrity of the micronuclear envelope delays or disrupts DNA replication, inhibits DNA repair, and exposes micronuclear DNA directly to cytoplasm. Micronuclei play a central role in tumorigenesis, with micronuclear DNA being a source of complex genome rearrangements (including chromothripsis) and promoting a cyclic GMP–AMP synthase (cGAS)-mediated cellular immune response that may contribute to cancer metastasis. Here, we discuss recent findings on how micronuclei are generated, what the consequences are, and what cellular mechanisms can be applied to protect against micronucleation.
Can a superabsorbent polymer help remediate compaction in frigid, semiarid soils? – a laboratory evaluation on soil physical processes

Superabsorbent polymers (SAPs) absorb more water than their mass. When applied to frigid, semiarid soils, they may modify physical processes and amplify winter freezing-thawing effects for remediat...
ß-arrestin 2 germline knockout does not attenuate opioid respiratory depression

Opioid drugs are commonly prescribed due to their powerful painkilling properties. However, when misused, these compounds can cause breathing to become dangerously slow and shallow: between 1999 and 2018, over 400,000 people died from opioid drug overdoses in the United States alone. Exactly how the drugs affect breathing remains unclear. What is known is that opioids work by binding to specific receptors at the surface of cells, an event which has a ripple effect on many biochemical pathways. Amongst these, research published in 2005 identified the β-arrestin 2 pathway as being responsible for altering breathing. This spurred efforts to find opioid-like drugs that would not interfere with the pathway, retaining their ability relieve pain but without affecting breathing. However, new evidence is now shedding doubt on the conclusions of this study. In response, Bachmutsky, Wei et al. attempted to replicate the original 2005 findings. Mice with carefully controlled genetic background were used, in which the genes for the β-arrestin 2 pathway were either present or absent. Both groups of animals had similar breathing patterns under normal conditions and after receiving an opioid drug. The results suggest β-arrestin 2 is not involved in opioid-induced breathing suppression. These findings demonstrate that research to develop opioid-like drugs that do not affect the β-arrestin 2 pathway are based on a false premise. Precisely targeting a drug’s molecular mechanisms to avoid suppressing breathing may still be a valid approach, but more research is needed to identify the right pathways.
Comparing accuracy of high-risk features for detecting advanced neoplasia in pancreatic cystic lesions: a systematic review and meta-analysis.

Background The American Gastroenterological Association recommends endoscopic ultrasound (EUS) for evaluating pancreatic cystic lesions (PCL) with ≥2 high-risk features (HRF), whereas the American College of Gastroenterology recommends EUS for ≥1 HRF. This systematic review and meta-analysis compared the diagnostic accuracy of using ≥1 vs. ≥2 HRF for assessing the risk of advanced neoplasia (AN) and performing EUS in PCL. Methods An electronic database search was performed for eligible studies. AN was defined as pancreatic adenocarcinoma, intraductal papillary mucinous neoplasm or mucinous cystadenoma with high-grade dysplasia, pancreatic intraepithelial neoplasia and pancreatic neuroendocrine tumors. HRF included cyst size ≥3 cm, solid component, and dilated pancreatic duct ≥5 mm. The primary outcome was the sensitivity and specificity of using ≥1 vs. ≥2 HRF as an indication for EUS to detect AN in PCL. Results Of 38 studies initially screened, 8 were included in the final analysis. Seven studies assessed the accuracy of ≥2 HRF and 4 studies assessed ≥1 HRF. The pooled sensitivity, specificity, positive and negative predictive values of EUS for detecting AN were 41.7% (95% confidence interval 19.5-67.8%), 90.8% (81.9-95.5%), 30.4% (19.4-44.2%) and 94.3% (89.6-97.0%) with ≥2HRFs, and 77.1% (66.1-85.3%), 72.7% (50.4-87.5%), 17.95% (10.3-29.4%), 98.1% (90.8-99.6%), respectively, with ≥1 HRF. Conclusion Performing EUS for PCL with ≥1 HRF could offer greater sensitivity in detecting AN compared to ≥2 HRF, with a similar negative predictive value.
A 200-GHz Power Amplifier With a Wideband Balanced Slot Power Combiner and 9.4-dBm P sat in 65-nm CMOS: Embedded Power Amplification

The effect of gain and embedding of amplifying cells (amp-cell) on the output power of power amplifiers (PAs) at high mm-wave frequencies is studied. This is the frequency range where matching loss becomes comparable with the gain of the amp-cell in most silicon technologies. By deriving power equations of embedded amp-cell, power contours are plotted in the gain plane and an optimum embedding is designed to maximize the output power for a desired gain. To showcase the theory, a high-frequency, high-power amp-cell, called matched cascode, is introduced and subsequently embedded to boost both power gain and output power. To increase the output power even further, a differential slot power combiner (SPC) is introduced and its equivalent circuit is analyzed. Finally, using the embedded matched cascode cell, and the SPC, a $2 \times 8$ PA is implemented in 65-nm bulk CMOS. It consumes 732 mW from 2.4-V supply voltage, with a maximum power-added efficiency (PAE) of 1.03%. The PA features a $P_{\text {sat}}$ and OP1dB of 9.4 and 6.3 dBm, respectively, at 200 GHz, and a maximum power gain of 19.5 dB.
Laser Induced Damage in Schott's OG-550 Optical Absorption Glass

Single and multiple shot laser induced damage threshold (LIDT) values were determined for Schott's OG-550 optical absorption glass using Q-switched 532 nm laser radiation. Bulk discoloration occurred for a single shot LIDT of 55 mJ/cm while surface pitting resulted at a single shot LIDT of 5.6 J/cm 2 . Multiple shot LIDTs were determined at 10, 5, and 2 Hz. For all three repetition rates, the multiple shot LIDTs decreased exponentially from the single shot LIDT, and level off at 35% of that value.
Prolapse of the urethra treated by the hepburn operation

Abstract Prolapse of the female urethra is a relatively rare condition which should be observed most frequently by gynecologists. Circular excesion of the prolapsed mucosa in a manner similar to the Whitehead operation for hemorrhoids is discarded in favor of the suprapubic suspension of the urethra and bladder as advocated by Hepburn. This operation is simple, effective, and gives lasting good results and can be performed not only in children, but also in the aged and even in the presence of marked debility. It seems probable that the angulation of the urethra which is accomplished by this suspension procedure may have a useful place in the treatment of urinary incontinence where the urethra and its voluntary sphincter have broken away from its normal attachments to the supporting fascia near the symphysis.
Turn-taking and affirmative cue words in task-oriented dialogue

As interactive voice response systems spread at a rapid pace, providing an increasingly more complex functionality, it is becoming clear that the challenges of such systems are not solely associated to their synthesis and recognition capabilities. Rather, issues such as the coordination of turn exchanges between system and user, or the correct generation and understanding of words that may convey multiple meanings, appear to play an important role in system usability. This thesis explores those two issues in the Columbia Games Corpus, a collection of spontaneous task-oriented dialogues in Standard American English. We provide evidence of the existence of seven turn-yielding cues—prosodic, acoustic and syntactic events strongly associated with conversational turn endings and show that the likelihood of a turn-taking attempt from the interlocutor increases linearly with the number of cues conjointly displayed by the speaker. We present similar results related to six backchannel-inviting cues—events that invite the interlocutor to produce a short utterance conveying continued attention. Additionally, we describe a series of studies of affirmative cue words—a family of cue words such as okay or alright that speakers use frequently in conversation for several purposes: for acknowledging what the interlocutor has said, or for cueing the start of a new topic, among others. We find differences in the acoustic/prosodic realization of such functions, but observe that contextual information figures prominently in human disambiguation of these words. We also conduct machine learning experiments to explore the automatic classification of affirmative cue words. Finally, we examine a novel measure of speaker entrainment related to the usage of these words, showing its association with task success and dialogue coordination.
Effect of glass-fibre reinforcement and annealing on microstructure and mechanical behaviour of nylon 6,6

The effects of glass-fibre reinforcement and annealing on the deformation and fracture behaviour of nylon 6,6 were investigated. The roles of glass fibres were examined by varying the glass fibre content and the fibre length, and by in situ fracture studies in front of crack tips. The effects of microstructural changes were investigated by imposing various annealing conditions on the specimens. The results indicated that the fracture toughness showed a sharp decrease due to stress concentrations at fibre ends when the fibre volume fraction was small. Above a critical fibre volume fraction, it was found that the fracture toughness can be substantially increased by enhanced localized matrix plasticity at fibre ends. The competing roles of glass fibre ends were consistent with microstructure sensitive fracture mechanics models of failure based on the attainment of a critical stress or strain over a critical microstructural distance in the crack-tip region. Upon annealing above a critical annealing time the unreinforced nylon 6,6 showed a drastic decrease in the strength and ductility, corresponding to a loss of the constant-load deformation region prior to necking. However, the fracture toughness of unreinforced nylon 6,6 was only moderately reduced by annealing. On the other hand, the fracture toughness of the composites showed a significant increase upon annealing. The combined effects of glass fibres and annealing on microstructures and overall property optimization of the composites are also discussed.
The effect of intraoperative mupirocin irrigation on Staphylococcus aureus within the maxillary sinus

Background Antibiotic irrigations are occasionally used during endoscopic sinus surgery when gross mucosal infection is present. These irrigations are thought to flush out pathogenic bacteria and decrease the bacterial load within the mucosal surfaces. This treatment, however, has not been studied in vivo and it is unknown whether antibiotic rinses produce a quantitative reduction in pathologic bacteria within the sinus mucosa. The objective of this study was to determine the relative abundance of Staphylococcus aureus within the maxillary sinus and to evaluate the impact of intraoperative mupirocin irrigation on bacterial burden. Methods Sixteen patients with symmetric maxillary chronic rhinosinusitis were prospectively enrolled. After bilateral maxillary antrostomies, biopsies were taken of the maxillary sinus mucosa on both sides. In each patient, the right side was irrigated with 240 mL of normal saline (NS) and the left side was irrigated with 240 mL of NS mixed with 60 mg mupirocin. Repeat maxillary sinus mucosal biopsies were taken from each side 7 to 10 days postsurgery. Each biopsy was analyzed using quantitative polymerase chain reaction to determine the presence and relative amount of S. aureus. Results Mupirocin irrigations were found to significantly reduce the amount of S. aureus found within the maxillary sinus mucosa compared to NS alone. The average fold change between the pre- and posttreatment biopsies on the right and left was 9.05 and 97.42, respectively (p < 0.01). Conclusion Intraoperative mupirocin irrigations significantly reduce the amount of S. aureus detected within the diseased sinus mucosa at up to 10 days postoperatively.
Hepatitis in Primates

Publisher Summary Nonhuman primates have played an important role in the recent major and rapid advances in hepatitis research. Most nonhuman primate associated hepatitis outbreaks in man are caused by human hepatitis A virus, or an antigenically very similar or identical nonhuman primate hepatitis virus. The possible role of human hepatitis C (HC) viruses in these outbreaks cannot be evaluated because the agents have not yet been defined. Efforts to infect a large number of animal species, including the common laboratory varieties, various nonhuman primates, and somewhat more exotic species such as canaries, oysters, and mini-pigs, all met with negative results except for some sporadic and inconsistent positive findings in nonhuman primates, chiefly in chimpanzees. It was observed that nonhuman primates and particularly chimpanzees could transmit hepatitis to man and that “spontaneous” biochemically and histologically typical viral hepatitis occurred in recently caught chimpanzees. A major advance in hepatitis A research was the discovery of virus-like particles that could be agglutinated specifically by human convalescent sera in the early acute phase stools of human cases of hepatitis A (HA). The next advancement came with the description of standard serological tests, complement fixation, and immune adherence for a hepatitis A associated antigen and its corresponding antibody.
Culture and Corruption: Using Hofstede’s Cultural Dimensions to Explain Perceptions of Corruption

Hofstede’s cultural dimensions are used to analyze the Corruption Perception Index of 47 countries. Using a linear regression model with the CPI as the dependent variable and culture as the independent variables, 65% of the perceptions of corruption is explained by four of Hofstede's cultural dimensions. Each dimension is significant at the
Curricula and State of the Profession

Most of us have encountered problems in developing an effective quantitative analysis program for our business schools in the United States. We have often found managers very reluctant to adopt QA techniques; on the other hand, students, although not reluctant, lacked the necessary mathematical background. During the academic year 1970–71, the authors assisted in the development of a QA department in the business school of a developing nation which offers both resident coursework for graduate students and executives seminars for businessmen. Both the students and the executives had the necessary mathematical background for rapid understanding of QA techniques. The executives appeared eager to use QA in their business operations and the students were highly motivated toward the application of QA to business problems. Our purpose in this article is not to convince all the QA professors to teach in underdeveloped nations, but to furnish information which is likely to be useful to those who attempt to establish similar QA programs in other developing countries.
Performance analysis of a LAN based remote terminal protocol

The author designs and analyzes the performance of a remote terminal protocol (RTP), called TAP, for use as a terminal access protocol in a 4BSD UNIX environment. He characterizes the workload by tracing user terminal activity on a multiuser timeshare machine. The trace analysis shows that user terminal traffic is bursty, with 99% of the traffic from the terminal being one byte long. The trace results are then used in the design of the TAP protocol and in the construction of a terminal workload under UNIX. The TAP protocol multiplexes individual terminal users onto a common LAN packet. Such a protocol imposes much less overhead on the host machine than existing protocols. Finally, the author makes a performance comparison of TAP and conventional RTPs under the constructed workload using a queuing model. He finds that TAP outperforms the other three protocols tested, due to the reduced number of packets. >
Stabilization of Microsatellite Sequences by Variant Repeats in the Yeast Saccharomyces cerevisiae

We examined the effect of a single variant repeat on the stability of a 51-base pair (bp) microsatellite (poly GT). We found that the insertion stabilizes the microsatellite about fivefold in wild-type strains. The stabilizing effect of the variant base was also observed in strains with mutations in the DNA mismatch repair genes pms1, msh2 and msh3, indicating that this effect does not require a functional DNA mismatch repair system. Most of the microsatellite alterations in the pms1, msh2 and msh3 strains were additions or deletions of single GT repeats, but about half of the alterations in the wild-type and msh6 strains were large (> 8 bp) deletions or additions.
Abrasive wear in multiphase microstructures

General theories of abrasive wear are reviewed, and wear is related to abrasive size, shape, hardness and degradation tendency. The effects of matrix and second phase flowfracture properties on abrasive wear resistance are discussed. Treatment of matrix effects includes the roles of matrix microhardness, subsurface deformation and retained austenite on abrasion resistance. Discussion of second phase particle effects includes abrasion in carbon steels, and wear in systems containing fine, medium and coarse carbides. Throughout the paper, general guidelines are presented for alloy design and material selection for abrasion resistance, where such guidelines appear to have validity. At the same time, examples are given of the more usual situation in which abrasive wear is a highly specific function of microstructure and abrasive properties. In these latter cases, the specific parameters which control abrasion resistance are delineated.
Nuclear data sheets for A = 181

The available nuclear structure information for all nuclei with mass number A = 181 is presented. Experimental data and their evaluation; comparison with theory, where possible; and arguments for spin, parity, and Nilsson-state assignments are given. Inconsistencies and discrepancies are indicated.
Static performance tests of a flight-type STOVL ejector

The design and development of thrust augmenting STOVL ejectors has typically been based on experimental iteration (i.e., trial and error). Static performance tests of a full scale vertical lift ejector were performed at primary flow temperatures up to 1560 R (1100 F). Flow visualization (smoke generators and yarn tufts) were used to view the inlet air flow, especially around the primary nozzle and end plates. Performance calculations are presented for ambient temperatures close to 480 R (20 F) and 535 R (75 F) which simulate seasonal aircraft operating conditions. Resulting thrust augmentation ratios are presented as functions of nozzle pressure ratio and temperature.
Corn Residue and Nitrogen Source Effects on Nitrogen Availability in No-Till Corn

Effective N management practices are needed in high residue corn (Zea mays L.) production systems to enhance N fertilizer efficiency and avoid yield reductions due to inadequate N supplies. This 4-yr study was conducted on a well-drained silt loam soil in southern Wisconsin (43°17' N, 89°22' E) to determine the effects of corn residue cover amounts on soil and residue N supplying capability, the effectiveness of several surface-applied N fertilizers, and the relative importance of mechanisms potentially contributing to reduced N efficiency in no-till corn systems. Treatments consisted of corn residue level [none (Ox), normal (1 x), twice normal (2x), and artificial (polypropylene) residue (AR1x)], N fertilizer source (ammonium nitrate, urea, and urea-ammonium nitrate solution), and N rate (0-225 kg N ha-1 in 45-kg increments). Increasing residue levels lowered soil temperatures and early season soil NO 3 -N production, and reduced corn grain yields without applied N. Ammonia losses reduced the effectiveness of urea-containing fertilizers but did not completely explain the observed N source differences. Nitrogen source effects were similar at all residue levels, suggesting that added N can overcome yield reductions at high residue levels. Yields, N mineralization, and soiltemperature were similar in the 1x and AR1x residue treatments,indicating that soil temperature rather than N immobilization is the main contributor to decreased yields at higher residue levels. Differences in early season soil NO 3 -N production and a similar difference in mean corn N requirement at the Ox and 1x residue levels, suggest that applying about 30 kg ha-1 of extra N will provide yield benefits in some years in no-till corn residue systems.
Homograft tympanic membrane in cats

A total of 91 cats were evaluated to determine the effectiveness and nature of closure of total tympanic membrane perforations with homografts preserved in buffered formaldehyde, 70 percent alcohol, benzalkonium in Tis-U-Sol (1:750 solution), or Cialit (1:5,000 aqueous solution). Controls consisted of unoperated ears, ears with partial and total perforations that were not grafted, ears in which the total tympanic membrane was removed and immediately replaced, and ears grafted with fresh homograft tympanic membranes. The study revealed that the removal of the tympanic annulus was necessary to prevent spontaneous regrowth of a new tympanic membrane. The percentage of successful closures of tympanic membrane perforations according to the preservative was formaldehyde 50 percent, alcohol 50 percent, benzalkonium 45 percent, and Cialit 30 percent. The rate of successful closures with fresh autograft tympanic membranes was 40 percent and with fresh homografts 25 percent. The homografts preserved in formaldehyde or alcohol were more rigid and easier to handle than were those preserved in benzalkonium or Cialit. The histologic findings were similar in ears that had developed a new tympanic membrane after grafting with preserved homograft tympanic membranes and in ears with fresh homografts or autografts. The graft served as an inert scaffold for the new tympanic membrane to grow across. Gelfoam used in the middle ear to support either a homograft or an autograft became incorporated into the new tympanic membrane and was associated with a foreign-body reaction. There was, however, no evidence of an immunologic reaction to the homograft.
Stroke prevention in atrial fibrillation

Non-valvular atrial fibrillation is a common and from a neurological perspective the most significant cardiac arrhythmia with a growing world-wide incidence. It also carries a significant associated morbidity and mortality, with cardioembolic strokes arguably being the most disabling sequelae. This brief review will highlight the important studies and the latest treatment modalities available for stroke prevention in patients with non-valvular atrial fibrillation.
Analysis of soybean lecithin by thin layer and analytical liquid chromatography.

The application of thin layer and analytical liquid chromatography to the analysis of two samples of commercial soybean lecithins is described. A combination of column chromatography and quantitative thin layer chromatography showed that these products consisted of ca. 82% mixture of the major phospholipids of soybeans, phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidyl inositol. The remainder of these products contained essentially the entire spectrum of lipid classes found in soybean oil-some 24 known and unknown glycolipids and phospholipids, in addition to the neutral lipids. Applications of analytical liquid chromatography to these lecithins gave a composition profile of the lipid classes comparable to two-dimensional thin layer chromatography. The potential of this method for the complete analysis of complex lipids, such as soybean lecithins, is indicated.
Extreme endurance and the metabolic range of sustained activity is uniquely available for every human not just the elite few

It is unclear whether the capabilities of recreationally active modern humans are unique due to present training practices or linked to the selection resulting from migration, escape, scavenging, and hunting and/or endurance running in early Homo. The purpose of this study was to determine upper values for total energy expenditure (TEE) and water turnover during sustained work for periods of 12-24 and 12-48 h, respectively and compare them with other species and proposed activities of early Homo. Stable isotopic water (2H218O) was used during competitions in hot environments to establish energy expenditure rates of approaching 10 times resting metabolism (RM) for 12.7 and 26.8 h, respectively. These events demonstrate pronounced hydration demands, with water output rates ranging from 25–95% of initial total body water for events lasting 12–48 h, respectively. These results provide new evidence for a high, sustained work (0.5–2 days) output and hydration demand in humans compared to other species in hot en...
Within Stimulus Prompting to Teach Symbol Discrimination Using an iPad® Speech Generating Device

This study evaluated the effects of within stimulus prompting and prompt fading to teach four preschool children with autism picture symbol discrimination using an iPad® and the Proloqu2Go application as a speech-generating device. Participants were taught to discriminate between a progressively more complex field of picture-symbols depicted on the screen of an iPad with a five-phased training procedure. All participants acquired discrimination between picture-symbols while using the iPad to mand for preferred items in a field of four picture-symbols. The results provide tentative support for a procedure to teach children with autism to discriminate between picture symbols while manding using a handheld speech-generating device.
Physics and dosimetry in computed tomography.

In this article the authors discuss basic features of image formation and radiation dose measurement computed tomography (CT) imaging. The various types of CT imaging scanners and the technical differences among them are discussed in other articles contained in this issue. This presentation is meant to be tutorial in nature and to provide the background needed to appraise the strengths and weaknesses of the imaging techniques described in the growing literature on cardiovascular CT imaging.
Pixel distribution analysis of B-mode ultrasound scan images predicts histologic features of atherosclerotic carotid plaques.

Abstract Background: The correlation of B-mode ultrasonographic morphology with histologic characteristics of atherosclerotic carotid plaques remains ill-defined. The classification of plaques with recently reported measures of plaque echogenicity and heterogeneity has been unsatisfactory. We used computer-assisted duplex ultrasound (DU) scan image analysis to determine echogenicity of specific tissues in control subjects. This information was used to quantify each tissue in imaged carotid plaques with pixel distribution analysis (PDA). These objective observations then were quantitatively compared with plaque histology in symptomatic and asymptomatic patients. Methods: We performed standardized DU scanning of healthy tissues in 10 volunteer subjects and of 20 carotid artery plaques (7 symptomatic and 13 asymptomatic) in 19 patients with carotid stenosis. The plaques underwent histologic analysis after carotid endarterectomy. The grayscale intensity ranges of blood, lipid, fibromuscular tissue, and calcium were calculated in the control subjects. With computer-assisted image analysis, B-mode images of plaques were linearly scaled to normalize data. Pixel distribution within the images then was analyzed. The grayscale ranges of known tissues obtained from control subjects helped define the amount of intraplaque hemorrhage, lipid, fibromuscular tissue, and calcium within carotid plaque images. This analysis was correlated with tissue composition measurements on histologic sections of excised plaques. Results: The median grayscale intensity (range) in control subjects was 2 (0 to 4) for blood, 12 (8 to 26) for lipid, 53 (41 to 76) for muscle, 172 (112 to 196) for fibrous tissue, and 221 (211 to 255) for calcium. PDA-derived predictions for blood, lipid, fibromuscular tissue, and calcium within carotid plaques correlated significantly with the histologic estimates of each tissue respectively (blood: P =.012; lipid: P =.0006; fibromuscular: P =.035; and calcium: P =.0001). A significantly higher amount of blood and lipid was seen within symptomatic plaques compared with asymptomatic ones ( P =.0048 and P =.026, respectively). Conversely, a larger amount of calcification was noted within asymptomatic plaques ( P =.0002). Conclusion: Computer-assisted PDA of DU scan images accurately quantified intraplaque hemorrhage, fibromuscular tissue, calcium, and lipid. Symptomatic plaques had lower calcium content but larger amounts of intraplaque hemorrhage and lipid. Quantitative PDA may be used to determine carotid plaque tissue composition to assist in the identification of symptomatic and potentially unstable asymptomatic plaques. (J Vasc Surg 2002;35:1210-7.)
Chemically assisted femtosecond laser machining for applications in LiNbO 3 and LiTaO 3

We introduce and optimize a fabrication procedure that employs both femtosecond laser machining and hydrofluoric acid etching for cutting holes or voids in slabs of lithium niobate and lithium tantalate. The fabricated structures have 3 μm lateral resolution, a lateral extent of at least several millimeters, and cut depths of up to 100 μm. Excellent surface quality is achieved by initially protecting the optical surface with a sacrificial silicon dioxide layer that is later removed during chemical etching. To optimize cut quality and machining speed, we explored various laser-machining parameters, including laser polarization, repetition rate, pulse duration, pulse energy, exposure time, and focusing, as well as scanning, protective coating, and etching procedures. The resulting structures significantly broaden the capabilities of terahertz polaritonics, in which lithium niobate and lithium tantalate are used for terahertz wave generation, imaging, and control. The approach should be applicable to a wide range of materials that are difficult to process by conventional methods.
Hyper-spherical coordinate reactive scattering using variational surface functions

Abstract An efficient numerical method of calculating surface functions for accurate quantum mechanical three-dimensional reactive scattering using symmetrized hyper-spherical coordinates has been developed. This method is at least 20 times faster than the finite-element method used previously and its accuracy is demonstrated for the H + H 2 system.
The physical properties of linear chain systems. I. The optical spectra of [(CH3)4N]NiCl3, Cs(Mg,Ni)Cl3, CsNiCl3, RbNiCl3 and CsNiBr3

Abstract The single crystal spectra of pure CsNiCl3, CsNiBr3, RbNiCl3, and [(CH3)4]NiCl3, and the single crystal spectrum of CsNiCl3 diluted in CsMgCl3 have been measured to 5°K. The spectra of the magnetically concentrated materials show a number of anomalously intense maxima. These are interpreted in terms of cooperative interactions.
Platelet Matrix Metalloprotease-1 Mediates Thrombogenesis by Activating PAR1 at a Cryptic Ligand Site

Matrix metalloproteases (MMPs) play important roles in normal and pathological remodeling processes including atherothrombotic disease, inflammation, angiogenesis, and cancer. MMPs have been viewed as matrix-degrading enzymes, but recent studies have shown that they possess direct signaling capabilities. Platelets harbor several MMPs that modulate hemostatic function and platelet survival; however their mode of action remains unknown. We show that platelet MMP-1 activates protease-activated receptor-1 (PAR1) on the surface of platelets. Exposure of platelets to fibrillar collagen converts the surface-bound proMMP-1 zymogen to active MMP-1, which promotes aggregation through PAR1. Unexpectedly, MMP-1 cleaves PAR1 at a distinct site that strongly activates Rho-GTP pathways, cell shape change and motility, and MAPK signaling. Blockade of MMP1-PAR1 curtails thrombogenesis under arterial flow conditions and inhibits thrombosis in animals. These studies provide a link between matrix-dependent activation of metalloproteases and platelet-G protein signaling and identify MMP1-PAR1 as a potential target for the prevention of arterial thrombosis.
Evaluation and Imaging of an Untreated Grade III Hamstring Tear: A Case Report

Background Muscle strains are one of the most common complaints treated by physicians. High-force lengthening contractions can produce very high forces resulting in pain and tissue damage; such strains are the most common cause of muscle injuries. The hamstring muscles are particularly susceptible as they cross two joints and regularly perform lengthening contractions during running. We describe a patient with return to full function after a large hamstring tear.