cssi/SciSciGPT-SciSciNet huggingface dataset:
Visualizing Disordered Single-Stranded RNA: Connecting Sequence, Structure, and Electrostatics

Disordered homopolymeric regions of single-stranded RNA, such as U or A tracts, are found within functional RNAs where they play distinct roles in defining molecular structure and facilitating recognition by partners. Despite this prominence, details of conformational and biophysical properties of these regions have not yet been resolved. We apply a number of experimental techniques to investigate the conformations of these biologically important motifs and provide quantitative measurements of their ion atmospheres. Single strands of RNA display pronounced sequence-dependent conformations that relate to the unique ion atmospheres each attracts. Chains of rU bases are relatively unstructured under all conditions, while chains of rA bases display distinct ordering through stacking or clustering motifs, depending on the composition of the surrounding solution. These dramatic structural differences are consistent with the measured disparity in ion composition and atmospheres around each homopolymer, revealing a complex interplay of base, ion, and single-strand ordering. The unique structural and ionic signatures of homopolymer ssRNAs explains their role(s) in folding structured RNAs and may explain their distinct recognition by protein partners.
Preventing Sexual Violence on College Campuses: An Investigation of Current Practices of Conducting Background Checks on Student-Athletes

Instances of sexual violence against women on college campuses is a major concern for university administrators. One approach to reducing instances of sexual violence on college campuses has been conducting background checks with more focused attention on student-athletes, though this approach is not without risk. Therefore, the purpose of this study was to investigate current practices of conducting background checks on student-athletes, and to present risk management strategies to reducing sexual violence on campus. Through a systematic data collection approach that included Freedom of Information Act (FOIA) requests of NCAA Division I public institutions, we found the implementation of background checks for student-athletes is a widely accepted practice, where policies were mandated by the athletic conference, state administrative law, or within the university. Recommendations for addressing sexual violence on campus include comprehensive sexual violence prevention education for students and student-athletes, including bystander intervention training. Additionally, if schools opt to utilize background checks, policies and procedures must be created to ensure due process, consistency for admissions, and staff training.
Exercise for Weight Loss: Further Evaluating Energy Compensation with Exercise.

PURPOSE This study assessed how individuals compensate for energy expended during a 12-wk aerobic exercise intervention, elucidating potential mechanisms and the role exercise dose plays in the compensatory response. PARTICIPANTS AND DESIGN Three-arm, randomized controlled trial among sedentary adults age 18 to 40 yr, body mass index of 25 to 35. Groups included six exercise sessions per week, two sessions per week, and sedentary control. METHODS Rate of exercise energy expenditure was calculated from a graded exercise test averaged across five heart rate zones. Energy compensation was calculated as the difference between expected weight loss (based on exercise energy expenditure) and changes in fat and fat-free mass (DXA). Resting energy expenditure was assessed via indirect calorimetry and concentrations of acylated ghrelin, leptin, insulin, and Glucagon-like peptide 1 (GLP-1) were assessed fasting and postprandial (six timepoints over 2 h). RESULTS The 6-d·wk group expended more energy (2753.5 kcal) and exercised longer (320.5 min) per week than the 2-d·wk group (1490.7 kcal, 1888.8 min, P < 0.05), resulting in greater fat loss compared with the 2-d or control groups (P < 0.05). Exercise groups did not differ in the % or total kcal compensated. Greater decreases in area under the curve (AUC) for acylated ghrelin predicted greater fat loss, regardless of group, energy expended per week, exercise duration, or exercise intensity. Changes in leptin AUC was the only independent predictor for energy compensation, with a greater decrease in leptin AUC predicting less energy compensation. Exercise frequency, energy expended, duration, or intensity did not influence energy compensation. CONCLUSIONS Leptin is an important factor in successful weight loss through exercise, with greater postprandial decreases promoting less compensation. Greater amounts of exercise do not influence the compensatory response to an exercise-induced energy deficit.
TEM FIB Lift-Out of Mount Saint Helens Volcanic Ash

Focused Ion Beam (FIB) specimen preparation for both scanning and transmission electron microscopy (SEM and TEM respectively) has seen an increase in usage over the past few years. The advantage to the FIB is that site specific cross sections (or plan view sections) may be fabricated quickly and reproducibly from numerous types of materials using a finely focused beam of Ga+ ions [1,2]. It was demonstrated by Prenitzer et al. that TEM specimens may be acquired from individual Zn powder particles by employing the FIB LO specimen preparation technique [3]. In this paper, we use the FIB LO technique to prepare TEM specimens from Mount Saint Helens volcanic ash.Volcanic ash from Mount Saint Helens was obtained at the Microscopy and Microanalysis 1998 meeting in Atlanta. TEM analysis of the ash was performed using the FIB lift out technique [1]. Ash powders were dusted onto an SEM sample stud that had been coated with silver paint.
Long-term international diversification of equities

Abstract Equity investors exhibit home bias although they can reduce risk with diversified global portfolios. We studied 118 years of data for 21 developed markets to investigate international diversification benefits for long-horizon equity investors. Investing equal proportions in all the markets would have increased Sharpe ratios only for investors in countries with low domestic ratios. Optimal global portfolios would have significantly increased Sharpe ratios for investors in all the countries. Allocating equal proportions to five optimal countries would have provided most of the maximum potential benefits of international diversification. Investors in countries with lower domestic Sharpe ratios would have benefited more from international diversification, primarily through risk reduction.
Assessment of the factors affecting health profession students' emergency transition during the COVID-19 pandemic: A cross-sectional study.

Objective: This study aimed to identify the factors that affected health profession students' emergency transition during the COVID-19 pandemic and to explore strategies that may help students be better prepared for any future health crises. Participants: This study population included 73 students that were originally enrolled in one online section (n = 49) and one face-to-face section (n = 24) of a healthcare administration course before the transition. Methods: The cross-sectional study was conducted and the anonymous survey data were analyzed using SPSS and a Man-Whitney U test. Results: Of the 73 students, 48 completed the survey, with a response rate of 66% (48/73). There was a statistically significant difference in the perceived COVID-19 impact (z=-3.339, p = 0.001) and difficulty transitioning during the pandemic (3-2.142, p = 0.032) between both groups. The top three hindering factors were stress and anxiety, difficulty focusing on studying at home, and time management due to uncertainty. Conclusions: The study findings suggest strategies that may help students with adequate knowledge and capabilities in managing stress, anxiety, and unprecedented challenges in the future.
Single-Stranded Polymer Modified by a Second Component, a Bound Ligand, or a Cap

In this third and final chapter on single-stranded, or effectively single-stranded, polymers, we consider perturbations produced by a second molecule. In Section 10, the “second molecule” is a second component that aggregates along with the first component. In Section 11, the “second molecule” is a ligand that binds to the aggregating species all along the polymeror, in other cases, the ligand binding is confined to the ends of the polymer. Section 27 deals with a somewhat related topic.
Water, Worship, and Wisdom: Indigenous Traditional Ecological Knowledge and the Human Right to Water

The relationship between religion and water, whether as spiritual symbol and ceremonial source, is virtually universal. This relationship is often very strong in the religious practices and beliefs of indigenous peoples, who typically have a strong spiritual connection to their traditional lands and waters. This connection is often manifested in “traditional ecological knowledge” (“TEK”), socially-beneficial environmental management practices and information transmitted by cultural, and often religious, tradition. As indigenous communities and the ecological integrity of indigenous traditional waters are threatened, indigenous people may turn to claims under international human rights as a means of protecting water resources and securing water rights. The current approach to the international human right to water is likely to prove inadequate for indigenous people to achieve protection of water quality and an equitable apportionment of water resources. A new approach to the human right to water, grounded in religious rights and religiously-based TEK, could provide a stronger protection for indigenous water rights and the water quality of traditional indigenous waters. This Essay proposes such an approach, as well as a framework for international courts to adjudicate indigenous religious rights-based claims to water resources.
Abstract 4105: Prevalence of breast stem cells in high-risk benign breast lesions and association with breastfeeding

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Background: Invasive breast cancers contain a subpopulation of cancer stem cells that are thought to maintain the heterogeneity and self-renewing potential of the tumor. In our previously published data, we demonstrated that stem cells in normal adjacent tissues were associated with triple negative breast cancer. The objective of this study is to determine the presence of stem cells in high risk breast lesions. We hypothesized that stem cells in high-risk lesions and normal adjacent breast tissue may represent a biomarker for increased breast cancer risk. Methods: We identified biopsies from 42 high-risk women seen in the Cancer Prevention Center at The University of Texas MD Anderson Cancer Center between 1988-2011. We collected information on breast cancer risk factors. The biopsies contained high-risk lesions including ductal carcinoma in situ (DCIS) n=21, lobular carcinoma in situ (LCIS) n=5, atypical ductal hyperplasia (ADH) n=7 and atypical lobular hyperplasia (ALH) n=6. The tissues were fluorescently labeled for stem cell markers CD44/CD49f/CD133, and were scored positive if more then 1% cells were positive for all markers using an automated fluorescent microscopy software. The presence of stem cell markers was compared in the normal adjacent tissues and high-risk lesions from a subset of 25 patients. Results: We identified stem cells in 46% of samples containing DCIS, 67% of LCIS, 63% of ALH, and 70% of ADH. There was a 79% concordance in stem cell positive status between the high-risk lesion and adjacent normal tissue. Women with positive stem cell high-risk lesions had no significant difference in age at first birth (24.4 years vs 26.6 years p=0.3), parity (1.7 vs 1.9, p=0.5), or body mass index (27.8 vs 31.8, p=0.07) compared to women without positive stem cell high-risk lesions. Women with positive stem cell high-risk lesions had shorter breastfeeding duration than women without (2.4 months vs 9.0 months p= 0.05). Conclusion: This is the first report, to our knowledge, that stem cells are present in some high-risk lesions and their associated normal breast tissue. Correlation with future development of invasive breast cancer could lay the foundation for future targeted breast cancer prevention strategies. Citation Format: Rachel L. Atkinson, Fraser Symmans, Therese B. Bevers, Wendy A. Woodward, Abenaa M. Brewster. Prevalence of breast stem cells in high-risk benign breast lesions and association with breastfeeding. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4105. doi:10.1158/1538-7445.AM2014-4105
Enabling MAC protocol implementations on software-defined radios

Over the past few years a range of new Media Access Control (MAC) protocols have been proposed for wireless networks. This research has been driven by the observation that a single one-size-fits-all MAC protocol cannot meet the needs of diverse wireless deployments and applications. Unfortunately, most MAC functionality has traditionally been implemented on the wireless card for performance reasons, thus, limiting the opportunities for MAC customization. Software-defined radios (SDRs) promise unprecedented flexibility, but their architecture has proven to be a challenge for MAC protocols. In this paper, we identify a minimum set of core MAC functions that must be implemented close to the radio in a high-latency SDR architecture to enable high performance and efficient MAC implementations. These functions include: precise scheduling in time, carrier sense, backoff, dependent packets, packet recognition, fine-grained radio control, and access to physical layer information. While we focus on an architecture where the bus latency exceeds common MAC interaction times (tens to hundreds of microseconds), other SDR architectures with lower latencies can also benefit from implementing a subset of these functions closer to the radio. We also define an API applicable to all SDR architectures that allows the host to control these functions, providing the necessary flexibility to implement a diverse range of MAC protocols. We show the effectiveness of our split-functionality approach through an implementation on the GNU Radio and USRP platforms. Our evaluation based on microbenchmarks and end-to-end network measurements, shows that our design can simultaneously achieve high flexibility and high performance.
Albinism and Hermansky‐Pudlak Syndrome

The term albinism refers to a group of congenital genetic abnormalities resulting from an inability of the pigment cell (melanocyte) to synthesize normal amounts of melanin pigment and is produced by mutations in at least 12 genes. Reduced melanin synthesis in the melanocytes of the skin, hair, and eyes produces oculocutaneous albinism, while a reduction primarily involving the retinal pigment epithelium produces ocular albinism. Hermansky-Pudlak syndrome includes the triad of oculocutaneous albinism, a mild bleeding diathesis, and a ceroid storage disease affecting primarily the lungs and the gut. Oculocutaneous albinism is the most common inherited disorder of generalized hypopigmentation, with an estimated frequency of 1 in 20,000 in most populations. It has been described in all ethnic groups and in all animal species making it one of the most widely distributed genetic abnormalities in the animal kingdom. Ocular albinism is less common with an estimated frequency of 1 in 50,000 to 1 in 60,000. It is X-linked. Hermansky-Pudlak syndrome is a rare condition in most populations. In the Puerto Rican population, however, two forms are found with type 1 having an estimated frequency of approximately 1 in 1800. Keywords: albinism; oculocutaneous albinism; ocular albinism; melanin; melanocytes; Hermansky-Pudlak syndrome; hypopigmentation; tyrosinase
Developing Pattern-Based Management Programs

We have recently proposed a novel approach to distributed management for large-scale, dynamic networks. Our approach, which we call pattern-based management, is based on the methodical use of distributed control schemes. From an engineering point of view, our approach has two advantages. First, it allows for estimating the performance characteristics of management operations in the design phase. (This was the subject of an earlier paper.) Second, it reduces the complexity of developing scalable, distributed management programs, by promoting the re-usability of key software components. In this paper, we demonstrate how pattern-based management programs can be designed and implemented. We propose an object model for these programs and give a concrete example of how a management task, such as obtaining the current link load distribution of the entire network, can be realized. The example illustrates that our model facilitates writing the key software components in a compact and elegant way.
Trace organic chemical contaminants in office spaces

Abstract We present data suggesting that workers in offices are exposed to a broad spectrum of solvent-related organic chemical contaminants present in very low concentrations relative to promulgated or recommended industrial hygiene exposure levels, but in high concentrations relative to outdoor air. With the aid of simple modeling, working hypotheses about various contaminant sources — new and aged building materials, wet-process photocopiers, tobacco smoke, and building maintenance products — are made with respect to the composition, amounts, and generation patterns of their emissions. The results show that effective control strategies can be implemented that do not compromise energy efficiency.
A note on the degeneracy of convex solutions to monge amperé equation

(1993). A note on the degeneracy of convex solutions to monge ampere equation. Communications in Partial Differential Equations: Vol. 18, No. 7-8, pp. 1213-1217.
Particle size and the rate of radiant heat transfer to gas-suspended particles

Radiant heat transfer to clouds composed of gas suspended solid particles of known concentration, relating radiant energy absorption to particle size
Age-dependent disruption in hippocampal theta oscillation in amyloid-β overproducing transgenic mice

Transgenic mice are used to model increased brain amyloid-β (Aβ) and amyloid plaque formation reflecting Alzheimer's disease pathology. In our study hippocampal network oscillations, population spikes, and long-term potentiation (LTP) were recorded in APPswe/PS1dE9 (APP/PS1) and presenilin1 (PS1) transgenic and wild type mice at 2, 4, and 8 months of age under urethane anesthesia. Hippocampal theta oscillations elicited by brainstem stimulation were similar in wild type and PS1 mice at all age groups. In contrast, APP/PS1 mice showed an age-dependent decrease in hippocampal activity, characterized by a significant decline in elicited theta power and frequency at 4 and 8 months. Magnitudes of population spikes and long-term potentiation in the dentate gyrus were similar across groups at both 4 and 8 months. In APP/PS1 mice, soluble and insoluble Aβ, and hippocampal and cortical plaque load increased with age, and the disruption in hippocampal theta oscillation showed a significant correlation with plaque load. Our study shows that, using in vivo electrophysiological methods, early Aβ-related functional deficits can be robustly detected in the brainstem-hippocampus multisynaptic network.
Candida endocarditis. Two new cases, with a review of twelve cases previously reported.

Abstract Two cases of Candida endocarditis are reported. Prior treatment of these patients with antibiotics in one case and with antibiotics and steroids in the second case suggests that these therapeutic agents may be important factors in the pathogenesis of the infection. The clinical and pathologic features of previously well-documented cases are also presented. Treatment with amphotericin B in one case of Candida endocarditis resulted in a prolonged reversal of the positive blood cultures, but the patient ultimately died. This drug appears to be an effective agent in the treatment of systemic fungus infections. We believe that fungus endocarditis will be encountered more frequently because of the increasing incidence of secondary fungus infections.
Customized course advising: investigating engineering student success with incoming profiles and patterns of concurrent course enrollment

Every college student registers for courses from a catalog of numerous offerings each term. Selecting the courses in which to enroll, and in what combinations, can dramatically impact each student's chances for academic success. Taking inspiration from the STEM Academy, we wanted to identify the characteristics of engineering students who graduate with 3.0 or above grade point average. The overall goal of the Customized Course Advising project is to determine the optimal term-by-term course selections for all engineering students based on their incoming characteristics and previous course history and performance, paying particular attention to concurrent enrollment. We found that ACT Math, SAT Math, and Advanced Placement exam can be effective measures to measure the students' academic preparation level. Also, we found that some concurrent course-enrollment patterns are highly predictive of first-term and overall academic success.
Tungsten Allylimido Complexes Cl4(RCN)W(NC3H5) as Single-Source CVD Precursors for WNxCy Thin Films. Correlation of Precursor Fragmentation to Film Properties

A mixture of the tungsten allylimido complexes Cl4(RCN)W(NC3H5) (3a, R = CH3 and 3b, R = Ph) was tested as a single-source precursor for growth of tungsten nitride (WNx) or carbonitride (WNxCy) thin films. Films deposited from 3a,b below 550 °C contained amorphous β-WNxCy, while those deposited at higher temperatures were polycrystalline. Film growth rates from 3a,b ranged from 5 to 10 A/min over a temperature range of 450−650 °C, and the apparent activation energy for film growth was 0.15 eV. A plot of the Ea values for deposition from Cl4(RCN)W(NR‘) [R‘ = Ph, iPr, allyl] against the N−C imido bond strengths for the analogous amines R‘NH2 is linear, implicating cleavage of the N−C bond as the rate-determining step in film growth. The correlation of mass spectral fragmentation patterns for Cl4(RCN)W(NR‘) with film properties such as nitrogen content supports the significance of facile N−C bond cleavage in film growth.
Excitation of acoustic-gravity waves in an isothermal atmosphere

The excitation of acoustic-gravity waves in an isothermal atmosphere is considered in this paper. It is shown that the excitation due to mass production, momentum production and heat production can be discussed by examining the same differential equation. The sources are assumed to be extended and vary both in time and in space. Asymptotic methods are used to obtain analytic expressions for the radiation field for all times, from the arrival of precursors to any time thereafter. It is found that the transient response results from contributions from one, two or all three modes depending on the times from the arrival of precursors. The three modes are the high frequency acoustic mode, the intermediate frequency buoyancy mode and the low frequency gravity mode. Additional features of the transient behavior depend on the temporal as well as spatial variation of the sources. An example is given for which numerical computations are made. Possible applications of the results to geophysical problems are duscussed and certain extensions of the results are proposed. DOI: 10.1111/j.2153-3490.1971.tb00558.x
Effects of bradykinin on the pulmonary vascular bed of the intact dog.

Abstract Intravenous infusion of bradykinin in intact dogs resulted in a significant increase in cardiac output, pulmonary blood volume, pulmonary artery pressure and pulmonary vein pressure and a significant decrease in systemic and total pulmonary vascular resistances. The decrease in total pulmonary vascular resistance was due to dilatation of the pulmonary arterioles, whereas the increase in pulmonary vein pressure was considered to be due to a shift of blood into the pulmonary venous system. The increase in pulmonary vein pressure with no change in left atrial pressure suggested a throttle valve action of the pulmonary veins, probably at the veno-left atrial junction. No evidence was obtained during these experiments to indicate that bradykinin actively dilates the pulmonary veins.
p38 mitogen-activated protein kinase inhibition attenuates intercellular adhesion molecule-1 up-regulation on human pulmonary microvascular endothelial cells.

Abstract Background: Increased expression of pulmonary endothelial intercellular adhesion molecule–1 (ICAM-1) is obligatory to neutrophil adherence culminating in adult respiratory distress syndrome (ARDS). The p38 mitogen-activated protein kinases (MAPKs) have been established as crucial in leukocyte proinflammatory signaling, but their role in the endothelial cell remains ill defined. We hypothesized that p38 MAPK activity is integral to ICAM-1 up-regulation on pulmonary endothelium. Methods: Human pulmonary microvascular endothelial cells (HMVECs) were grown to confluence and pretreated with either the tyrosine phophorylation inhibitor herbimycin A (1 μmol/L) or the p38 MAPK inhibitor SB203580 (10–7 to 10–5 mol/L) for 6 hours. ICAM-1 expression was quantified by flow cytometry. Data are expressed as mean fluorescence intensity. Western blotting was used to show p38 MAPK activity after stimulation with lipopolysaccharide (LPS) or tumor necrosis factor–α (TNF-α). Results: Tyrosine phosphorylation inhibition with herbimycin A attenuated both LPS and TNF-α stimulated ICAM-1 up-regulation. Similarly, specific inhibition of p38 MAPK attenuated both LPS (10-6 to 10-5 mol/L SB203580) and TNF-α (10-7to 10-5 mol/L SB203580) stimulated expression of ICAM-1 on HMVECs. Both LPS and TNF-α induced activation of p38 in HMVECs. Conclusions: Signaling through p38 MAPKs contributes to LPS and TNF-α stimulated ICAM-1 surface expression on HMVECs. Thus p38 MAPKs appear integral to both neutrophil and endothelial cell proinflammatory signaling and may be a potential therapeutic target in the treatment of ARDS. (Surgery 1998;124:403-8.)
Weathering products within microcracks in feldspars

Tonalite cobbles from moraines in the Tobacco Root Mountains, Montana, have weathering rinds in which the feldspars are altered to clays along microcracks. Energy-dispersive X-ray and X-ray diffraction analyses have shown that microcracks in orthoclase contain only kaolinite but that microcracks in oligoclase contain a central zone of kaolinite surrounded by a zone of smectite. These observations are in accord with predictions based on activity diagrams for the appropriate chemical systems. Feldspar dissolution was probably the rate-determining step in the development of the microcracks and their clay fillings.
Transmission properties of polyethylene-insulated telephone cables at voice and carrier frequencies

In the last few years, amplitudemodulated carrier telephone systems up to about 250 kc have been routed over polyethylene toll cables and frequencymodulated carrier telephone systems up to about 350 kc have been routed over entrance cable for open-wire circuits. Trunk cable carrier systems with top frequencies of 400 kc or more are under development. Study is being given to pulse-code-modulated cable carrier systems with top frequencies of a megacycle or more. The problems of crosstalk control and noise shielding at carrier frequencies have, therefore, become of prime importance.
Relationships between osteocyte density and bone formation rate in human cancellous bone

Iliac cancellous osteocyte density decreases with age in deep bone but not in superficial bone, most likely because of remodeling. It has been suggested that osteocytes can inhibit bone remodeling. Accordingly, we examined the relationship between osteocyte density and bone formation rate in 92 healthy women. In superficial bone (<25 μm from the surface), we found a weak but significant (p < 0.03) inverse correlation between BFR/BS and Ot. N/B.Ar that was unaffected by menopause and independent of age. A weaker positive relationship with empty lacunar density improved significance. The data appear to suggest a negative feedback loop, but osteocytes explain only 10% of the variance in BFR/BS, and 97% of the variance in osteocyte density is explained by total lacunar density. This measure of initial osteocyte density during bone formation has a high coefficient of variation (20%) indicating large individual differences. We conclude that: (1) our data support the proposal that osteocytes can inhibit bone remodeling; (2) osteocyte density in superficial bone depends mainly on initial osteocyte density during bone formation and is maintained but not regulated by bone remodeling; and (3) the inverse relationship between BFR/BS and osteocyte density may reflect the homeostatic need to maintain calcium exchangeability in the lining cell–osteocyte syncytium.
Moderating effects of prior knowledge on the perceived diagnosticity of beliefs derived from implicit versus explicit product claims

Abstract An experiment was conducted to examine the effects of prior knowledge on the perceived diagnosticity of beliefs derived from directly stated versus implied product claims. Subjects were exposed to sets of arguments implying several conclusions about specific product benefits. These conclusions were either stated directly in the text (explicit conclusions) or omitted (implicit conclusions). Degree of belief in the target conclusions and the perceived diagnosticity of these beliefs was assessed by computing Bayesian likelihood ratios on the basis of subjects' component probability estimates. As predicted, low knowledge subjects perceived their beliefs to be more diagnostic when they were based on explicit (versus implicit) conclusions. By contrast, high knowledge subjects perceived their beliefs as diagnostic across conditions. Implications of the results for understanding the role of consumer inference processes in advertising are discussed.
Lynn Margulis (1938–2011)

Science progresses mainly through experimentation, but to become useful, experimental results have to be scrutinized, interpreted, and placed on a proper intellectual scaffold. These two activities are not always carried out evenly by the same person. Some scientists become known for their impressive experiments, others for innovative theoretical syntheses. Lynn Margulis, who died on 22 November 2011 at the age of 73, was a striking example of the latter group. She is responsible for the transformative idea that eukaryotic cells evolved by the acquisition and exploitation of other, smaller cells, a process known as endosymbiosis. Accordingly, essential components of eukaryotic cells—the organelles mitochondria and, in photosynthetic cells, plastids—are derived from bacteria that some ancestral cell had ingested. These events are thought to have taken place early in the history of life on Earth.
Reliability of Individual Frontal Plane Axis Determination

In a sample of 649 healthy men, the QRS and T amplitude frontal plane QRS and T axes and mean vectors were determined from leads I and III (standard reference), II and III, I and II, I and aV F , aV L and aV F , and from a vectorial combination of leads I, II, and III. The group means were similar, but there were large intraindividual differences of the QRS axis (up to ± 35°) and, to a somewhat lesser degree, of the T axis between the different lead combinations. Hypothetically, the axes from different lead combinations should be identical. The intraindividual discrepancies of the mean frontal plane vectors were also large (about 20%). In a smaller sample of 50 healthy men the axis was also determined from Frank X, Y leads, and the QRS and T axes were determined from both amplitudes (as in the larger sample) and areas. The results were similar to those obtained in the larger sample: no significant differences in the group means, but large intraindividual discrepancies between the various lead combinations both for amplitude and area axes. It is concluded that the normal standards obtained for the axis determined from leads I and III are also valid for the other lead combinations, but that for the individual patient there is no assurance that the axis determined from any one lead combination will be the true axis, even with a liberal range of error. The major part of the variation in axis as measured from various lead combinations is attributable in this study to time disparity between components measured in the individual leads, but skin impedance contributes substantially in many conventional measurements. For a patient in whom the axis is considered to be of diagnostic importance, it is probably worth averaging axes determined by several different lead combinations.
Design of non-magnetic optical cloak

We present the design and analysis of a non-magnetic cloak operating at optical frequencies. The general recipe for the implementation of such a device is provided. The cloaking performance is illustrated with finite-element simulations.
Optical Imaging and Spectroscopy of the Galactic Supernova Remnant 3C 58 (G130.7+3.1)

We present a comprehensive imaging and spectroscopic survey of optical emission knots associated with the young Galactic supernova remnant 3C 58. Hα images show hundreds of clumpy filaments and knots arranged in a complex structure covering a nearly circular area roughly 400'' in diameter. A quite different emission structure is seen in [O III], where the brightest features are less clumpy and largely confined to the remnant's northwest quadrant. Measured radial velocities of over 450 knots reveal two distinct kinematic populations; one with average and peak expansion velocities of 770 and 1100 km s−1, respectively, forming a thick shell, and the other showing |v| ≤ 250 km s−1. High-velocity knots (|v| ≥ 500 km s−1) exhibit a strong bipolar expansion pattern with redshifted and blueshifted knots located in northeastern and southwestern regions, respectively. These knots also show strong [N II]/Hα line emission ratios, suggesting enhanced N/H. In contrast, the slower expanding knot population shows much lower [N II]/Hα line ratios and likely represents circumstellar mass loss material from the 3C 58 progenitor. Proper-motion estimates using images spanning a 28 yr time interval suggest positional shifts of between 0.5'' and 2.0'', implying proper motions of 0.02''-0.07'' yr−1. These values agree with previous estimates but are much less than the ≈0.2'' yr−1 expected if 3C 58 were associated with historic guest star of 1181 CE.
The use of hop-limits to provide survivable ATM group communications

We examine the use of a hop-limit constraint with techniques to provide survivability for connection-oriented ATM group communications. A hop-limit constraint is an approach that has evolved from solving point-to-point routing problems but has not been fully developed for group communications. A hop-limit: (1) limits the number of routes considered such that the routing problems of higher order complexity can be solved and (2) limits the length of any individual route to meet specific Quality of Service guarantees (such as delay). This paper focuses on the former. We compare the feasibility and cost of providing survivability using working multipoint routes with disjoint dedicated backup multipoint routes, where the multipoint routes are setup using either Self-Healing Rings, Shared Multicast Trees, or VC Meshes. We found that hop-limit constraints allowed us to exactly solve NP-complete routing problem on real networks.
Vertical Positioning of Internal Molecular Scaffolding within a Single Molecular Layer

Three-dimensional design within a two-dimensional molecular layer is demonstrated by varying the vertical positioning of internal molecular scaffolding. Monolayer structures are successfully fabricated using photopolymerization of adjacent diacetylene-containing molecules with controlled position of the resultant polymer backbone. Regardless of diacetylene position within the monolayer, polymerization is shown for all molecular architectures. The effective conjugation length of the resulting monolayer polymer, however, appears to be dependent on the molecular architecture. Although no significant expansion or contraction is expected upon polymerization, changes in hybridization must be accommodated within the monolayer structure. While the spatial constraints for polymerization are considerable, the longest conjugation lengths are exhibited by molecular architectures with some disordered component within the alkyl side chains. The excellent long-range order in these monolayers, as demonstrated by heteroge...
Behavioral Side Effects of Fluoxetine in Children and Adolescents

ABSTRACT Twelve (50%) of 24 children, ages 8 to 16 years, treated with fluoxetine, 20 or 40 mg/day, for depressive or obsessive compulsive symptoms, developed behavioral side effects characterized by motor restlessness (n = 11), sleep disturbance (n = 11), social disinhibition (n = 6), or a subjective sensation of excitation (n = 3). No major changes in the neurological status of these children were observed. However, the three children with ADHD showed an exacerbation of symptoms on fluoxetine. Discontinuation (n = 5) or halving the dosage (n = 7) resulted in complete resolution of these unwanted symptoms within 1 to 2 weeks. In all 7 children whose doses were reduced, improvement of the depressive or obsessive compulsive symptoms was maintained on the lower dosage. Clinicians treating children with fluoxetine are cautioned to be aware of behavioral side effects which may be alleviated by dosage reduction or possibly by starting with lower doses. These side effects may be difficult to differentiate from ...
Derived Equivalence of Surface Algebras in Genus 0 via Graded Equivalence

We determine some of the derived equivalences of a class of gentle algebras called surface algebras. These algebras are constructed from an unpunctured Riemann surface of genus 0 with boundary and marked points by introducing cuts in internal triangles of an arbitrary triangulation of the surface. In particular, we fix a triangulation of a surface and determine when different cuts produce derived equivalent algebras.
Entanglement entropy and multifractality at localization transitions

The von Neumann entanglement entropy is a useful measure to characterize a quantum phase transition. We investigate the nonanalyticity of this entropy at disorder-dominated quantum phase transitions in noninteracting electronic systems. At these critical points, the von Neumann entropy is determined by the single particle wave function intensity, which exhibits complex scale invariant fluctuations. We find that the concept of multifractality is naturally suited for studying von Neumann entropy of the critical wave functions. Our numerical simulations of the three dimensional Anderson localization transition and the integer quantum Hall plateau transition show that the entanglement at these transitions is well described using multifractal analysis.
Poled amorphous polymers for second-order nonlinear optics

Recent advances in poled amorphous polymers for second-order nonlinear optics are discussed with emphasis on stabilizing the frozen-in nonlinearity via chemical crosslinking under electric fields. Specific examples of a linear polymer and a crosslinked polymer, both with nitroaniline-type chromophores covalently attached as side groups, are presented and compared in their glass transition behavior, linear optical properties, poling dynamics, and stability of frozen-in nonlinearity. It is demonstrated that by employing chemical crosslinking under electric fields one can prepare highly efficient and stable poled polymers that exhibit no decay in nonlinearity at ambient conditions and no apparent tendency of decay even at 85°C as well as excellent optical properties. The historical development of organic materials for second-order nonlinear optics and recent advances in device fabrication based on poled polymers are also discussed briefly.
Temporal Variations in Cell Migration and Traction during Fibroblast-Mediated Gel Compaction

Current models used in our laboratory to assess the migration and traction of a population of cells within biopolymer gels are extended to investigate temporal changes in these parameters during compaction of mechanically constrained gels. The random cell migration coefficient, μ(t) is calculated using a windowing technique by regressing the mean-squared displacement of cells tracked at high magnification in three dimensions with a generalized least squares algorithm for a subset of experimental time intervals, and then shifting the window interval-by-interval until all time points are analyzed. The cell traction parameter, τ0(t), is determined by optimizing the solution of our anisotropic biphasic theory to tissue equivalent compaction. The windowing technique captured simulated sinusoidal and step changes in cell migration superposed on a persistent random walk in simulated cell movement. The optimization software captured simulated time dependence of compaction on cell spreading. Employment of these techniques on experimental data using rat dermal fibroblasts (RDFs) and human foreskin fibroblasts (HFFs) demonstrated that these cells exhibit different migration-traction relationships. Rat dermal fibroblast migration was negatively correlated to traction, suggesting migration was not the driving force for compaction with these cells, whereas human foreskin fibroblast migration was positively correlated to traction.
The determination of volume of Dunaliella cells by transmission electron microscopy and image analysis

A method has been developed to measure the cell volume of the unicellular, green alga Dunaliella bioculata 19/4 during salt stress conditions, where shape change in the alga becomes problematic and the cells can no longer be recognised as 'prolate ellipsoids', by using image analysis of transmission electron micrographs. The image analysis of the micrographs employs a specialised numerical integration programme or 'variable frames analysis' for unicellular microorganisms which possess a single axis of symmetry. Basic mathematics was used to determine: (a) the functional dependence of the calculated volume on the angle of the cut to the axis of symmetry and the distance of the origin of the cut from the centre of mass; (b) errors resulting from the orientation of the longest axis off-vertical for image analysis; (c) the uppermost range of calculated volumes obtained which represent the 'true' volumes within required confidence levels. The procedure was applied to a series of experiments on the effects of salt stress on Dunaliella bioculata cells.
The Relation of the Positron Energy Spectrum to the Decay Constant and to the Energy of the Bombarding Protons

We have reported(1) approximate energy distributions of the positrons emitted by various substances activated by proton or deuton bombardment. A typical photograph is reproduced in Fig. 1. To find whether a relation exists between the maximum energy of the bombarding particles and the energies of the disintegration positrons we have studied numerous samples of carbon bombarded by protons at peak voltages of 900,000 and 700,000, supplied us by Dr. Lauritsen and Mr. Crane.
Chlordiazepoxide and the determinants of negative contrast

Previous experiments have shown that the negative contrast effect in consummatory behavior that occurs when rats are shifted from 32% to 4% sucrose is alleviated by the tranquilizer chlordiazepoxide (CDP). However, in these experiments, CDP was effective on the second postshift day but not on the first postshift day. The three experiments described in this paper suggest that this differential effectiveness of CDP is not due to the difference in preshift-postshift retention intervals on Day 1 (24 h) and Day 2 (48 h), but is due instead to the necessity of some degree of experience (about 5 min) with the postshift solution. These results, combined with those of an earlier study which showed elevated corticosterone in shifted animals on the second postshift day but not on the first postshift day, suggest that negative contrast may be a dynamic process, involving sequential processes of detection, evaluation, and conflict over the postshift period. It was further suggested that CDP becomes effective in moderating contrast only when the conflict stage is reached.
Höhere Kommunikationsprotokolle am Beispiel Bildschirmtext

Traditionelle Datenfernverarbeitung und Datenbanksysteme verschmelzen zu Informationssystemen zeitgemaser Pragung; neutrale Kommunikationsprotokolle bilden die technische Basis fur neue, anspruchsvolle Anwendungen der Informationstechnik. Mit dem OSI-Referenzmodell und den daraus abgeleiteten Normen leistet die internationale Normung einen wesentlichen Beitrag zur technischen Verstandigung zwischen unterschiedlichen Kommunikationssystemen. Der Artikel beschreibt im Teil 1 grundsatzliche Aspekte der Systemkommunikation und der Normung von Kommunikationsprotokollen; Teil 2 behandelt die Einbindung von neutralen Protokollen in eine vielschichtige Anwendungsumgebung, Bildschirmtext.
Perceived Environmental Uncertainty: An Individual or Environmental Attribute?

The antecedents of perceived environmental uncertainty (PEU) were examined in two laboratory experiments to explore the relationship of PEU to environment and individual subjects' characteristic(s). Analysis showed differences between the more abstract "general" PEU items and more specific "task-related" PEU items. Measures of individual characteristics were not related to the task-related PEU Index, but were related to the more "general" measures of PEU. An experimental manipulation of "objective" environmental uncertainty showed task-related PEU to be strongly related to this objective uncertainty manipulation. Task-related PEU was also related secondarily, to individual characteristics. This same result was also found in a second experiment. The results of both experiments suggest that task-related operationalizations of PEU (as opposed to more general measures) minimize the impact of individual differences on the perceptual measure of PEU.
Regional longitudinal bi-ventricular function in pulmonary hypertension: single heart-beat assessment of strain by fast-senc imaging

Purpose Right ventricular (RV) function is the most important determinant of survival in patients with pulmonary hypertension (PH), thus monitoring of RV function is critical. However, RV regional function assessment is challenging using current MR tagging techniques. Thus, the purpose was to evaluate regional longitudinal ventricular deformation (ELL) acquired by free breathing single heart-beat fast strain encoded imaging (fast-SENC) in relation to global ventricular dysfunction markers and pulmonary hemodynamics in PH patients.
Comparison of normal and breast cancer cell lines using proteome, genome, and interactome data.

Normal and cancer cell line proteomes were profiled using high throughput mass spectrometry techniques. Application of protein-level and peptide-level sample fractionation combined with LC−MS/MS analysis enabled identification of 2235 unmodified proteins representing a broad range of functional and compartmental classes. An iterative multistep search strategy was used to identify post-translational modifications, revealing several proteins that are preferentially modified in cancer cells. Information regarding both unmodified and modified protein forms was combined with publicly available gene expression and protein−protein interaction data. The resulting integrated dataset revealed several functionally related proteins that are differentially regulated between normal and cancer cell lines. Keywords: post-translational modifications • breast cancer • proteome • mass spectrometry • membrane proteins • high throughput • subcellular • multidimensional liquid chromatography • functional genomics • pathways