cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynactin integrity depends upon direct binding of dynamitin to Arp1

Dynactin is a multiprotein complex that works with cytoplasmic dynein and other motors to support a wide range of cell functions. It serves as an adaptor that binds both dynein and cargoes and enhances single-motor processivity. The dynactin subunit dynamitin (also known as p50) is believed to be integral to dynactin structure because free dynamitin displaces the dynein-binding p150Glued subunit from the cargo-binding Arp1 filament. We show here that the intrinsically disordered dynamitin N-terminus binds to Arp1 directly. When expressed in cells, dynamitin amino acids (AA) 1–87 causes complete release of endogenous dynamitin, p150, and p24 from dynactin, leaving behind Arp1 filaments carrying the remaining dynactin subunits (CapZ, p62, Arp11, p27, and p25). Tandem-affinity purification–tagged dynamitin AA 1–87 binds the Arp filament specifically, and binding studies with purified native Arp1 reveal that this fragment binds Arp1 directly. Neither CapZ nor the p27/p25 dimer contributes to interactions between dynamitin and the Arp filament. This work demonstrates for the first time that Arp1 can directly bind any protein besides another Arp and provides important new insight into the underpinnings of dynactin structure.
Stack layout transformation: towards diversity for securing binary programs

Despite protracted efforts by both researchers and practitioners, security vulnerabilities remain in modern software. Artificial diversity is an effective defense against many types of attack, and one form, address-space randomization, has been widely applied. Present artificial diversity implementations are either coarse-grained or require source code. Because of the widespread use of software of unknown provenance, e.g., libraries, where no source code is provided or available, building diversity into the source code is not always possible. I investigate an approach to stack layout transformation that operates on x86 binary programs, which would allow users to obfuscate vulnerabilities and increase their confidence in the software’s dependability. The proposed approach is speculative: the stack frame layout for a function is inferred from the binary and assessed by executing the transformed program. Upon assessment failure, the inferred layout is refined in hopes to better reflect the actual function layout.
Efficiency trends and limits from comprehensive microarchitectural adaptivity

Increasing demand for power-efficient, high-performance computing requires tuning applications and/or the underlying hardware to improve the mapping between workload heterogeneity and computational resources. To assess the potential benefits of hardware tuning, we propose a framework that leverages synergistic interactions between recent advances in (a) sampling, (b) predictive modeling, and (c) optimization heuristics. This framework enables qualitatively new capabilities in analyzing the performance and power characteristics of adaptive microarchitectures. For the first time, we are able to simultaneously consider high temporal and comprehensive spatial adaptivity. In particular, we optimize efficiency for many, short adaptive intervals and identify the best configuration of 15 parameters, which define a space of 240B point.With frequent sub-application reconfiguration and a fully reconfigurable hardware substrate, adaptive microarchitectures achieve bips3/w efficiency gains of up to 5.3x (median 2.4x) relative to their static counterparts already optimized for a given application. This 5.3x efficiency gain is derived from a 1.6x performance gain and 0.8x power reduction. Although several applications achieve a significant fraction of their potential efficiency with as few as three adaptive parameters, the three most significant parameters differ across applications. These differences motivate a hardware substrate capable of comprehensive adaptivity to meet these diverse application requirements.
Vertical emitting lasers based on 2D Photonic Crystal heterostructure coupled to strip silicon waveguide

We fabricate a compact 2D photonic crystal (PC) vertical emitting laser at 1.5 mum, based on slow Bloch mode confinement in a 20 PC heterostructure. The 2D PC, consisting of a square lattice of indium phosphide (InP) micropillar, is bonded on a silicon/silica Bragg mirror. We study the coupling between the 2D PC heterostructure and a silicon strip waveguide around the lasing wavelength.
Dueling quorum sensing systems in Pseudomonas aeruginosa control the production of the Pseudomonas quinolone signal (PQS)

The opportunistic human pathogen Pseudomonas aeruginosa regulates the production of numerous virulence factors via the action of two separate but coordinated quorum sensing systems, las and rhl. These systems control the transcription of genes in response to population density through the intercellular signals N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C(12)-HSL) and N-(butanoyl)-L-homoserine lactone (C(4)-HSL). A third P. aeruginosa signal, 2-heptyl-3-hydroxy-4-quinolone [Pseudomonas quinolone signal (PQS)], also plays a significant role in the transcription of multiple P. aeruginosa virulence genes. PQS is intertwined in the P. aeruginosa quorum sensing hierarchy with its production and bioactivity requiring the las and rhl quorum sensing systems, respectively. This report presents a preliminary transcriptional analysis of pqsA, the first gene of the recently discovered PQS biosynthetic gene cluster. We show that pqsA transcription required pqsR, a transcriptional activator protein encoded within the PQS biosynthetic gene cluster. It was also found that the transcription of pqsA and subsequent production of PQS was induced by the las quorum sensing system and repressed by the rhl quorum sensing system. In addition, PQS production was dependent on the ratio of 3-oxo-C(12)-HSL to C(4)-HSL, suggesting a regulatory balance between quorum sensing systems. These data are an important early step toward understanding the regulation of PQS synthesis and the role of PQS in P. aeruginosa intercellular signaling.
Stability of chemical sequence in a periodic polymeric nematogen

The stability of a polymeric nematogen's chemical sequence was studied by differential scanning calorimetry, optical microscopy, and 13C-NMR; the nematogen studied was a thermotropic polyester and had a periodic chemical structure. Model compounds were used to investigate transesterfication in the melt at different temperatures with the addition of phenol or benzoic acid as analogues of polymer end groups. Ester interchange reactions at high temperature were found to be partly suppressed when acidic end groups of the periodic nematogen were capped. However, sequence reorganization was completely suppressed in capped nematogens when temperatures remained below the isotropization transition of the nematogen investigated. Rapid disordering of the periodic nematogen was observed above the nematic-isotropic transition, suggesting that both chemical and physical factors play a role in sequence redistribution of periodic nematogens. © 1994 John Wiley & Sons, Inc.
A pheromone outweighs temperature in influencing migration of sea lamprey

Organisms continuously acquire and process information from surrounding cues. While some cues complement one another in delivering more reliable information, others may provide conflicting information. How organisms extract and use reliable information from a multitude of cues is largely unknown. We examined movement decisions of sea lampreys (Petromyzon marinus L.) exposed to a conspecific and an environmental cue during pre-spawning migration. Specifically, we predicted that the mature male-released sex pheromone 3-keto petromyzonol sulfate (3kPZS) will outweigh the locomotor inhibiting effects of cold stream temperature (less than 15°C). Using large-scale stream bioassays, we found that 3kPZS elicits an increase (more than 40%) in upstream movement of pre-spawning lampreys when the water temperatures were below 15°C. Both warming temperatures and conspecific cues increase upstream movement when the water temperature rose above 15°C. These patterns define an interaction between abiotic and conspecific cues in modulating animal decision-making, providing an example of the hierarchy of contradictory information.
Characterization of crust and upper mantle structure under LASA as a random medium

abstract The amplitude and slowness anomalies for P waves have been measured, at 0.8 Hz, within the nine subarrays located on the A, B, C rings at LASA. These measurements are made possible by the use of a high-resolution wave-number analysis program. It is found that these anomalies exhibit remarkably large fluctuations between the various relatively closely spaced subarrays. A model is proposed to explain these variations in which the crust and upper mantle structure under LASA is characterized as a random, or Chernov-type, medium. A statistical analysis of the amplitude, phase, and slowness fluctuations is made which, along with some theoretical results due to Chernov, are used to determine the properties of the random medium. It is found that the correlation distance of the random medium is 12 km and that the standard deviation of the index of refraction is 1.9 per cent. These random inhomogeneities are determined to exist in the crust and upper mantle of the Earth down to a depth of about 136 km.
Direct observation of ultrafast dynamics of electron thermalization in gold

Using time-resolved surface second harmonic generation (SHG), an electron temperature dependent enhancement in the SHG signal is observed, for the first time, in the high temperature regime resolving the thermalization of nonequilibrium hot electrons.
Confronting cisternae presenting as intracytoplasmic inclusions in monocytes.

Small gray-blue intracytoplasmic inclusions were noted in the peripheral monocytes and neutrophils from a patient with renal failure. Ultrastructural analysis revealed confronting cisternae within the cytoplasm. The authors submit a case report to introduce a previously undescribed morphologic feature of leukocytes that may be mistaken at the light microscopic level for Dohle bodies or other inclusions.
Silicon Pedestal Ultra-high Q Microdisk Resonators: A Novel Device Architecture to Suppress Thermal Instability and Enable Active Integration

Silicon-on-insulator microdisk resonators with two structures of disk-on-oxide and disk-on-silicon-pedestal are fabricated and compared. Pedestal architecture exhibits a dramatic improvement in the thermal resistance, thereby, increasing the threshold for thermal instability. Experimental Q~3×106 is observed.
Dynamisches Verhalten von Elastomeren bei großen Dehnungen überlagerten kleinen Schwingungen

Die dynamischen Eigenschaften eines Styrol-Butadien-Copolymers und eines Naturkautschuks sind als Funktion einer statischen Vorverstreckung gemessen worden. Die dynamische Viskositatη dieser Polymeren andert sich nicht bis zu einer statischen Verstreckung von ca. 1,7, und die dynamische Spannungsamplitude ist der Steigung der statischen Spannungs-Dehnungs-Kurve proportional. Der Tangens des Verlustwinkels hangt nicht nur von der dynamischen Viskositat, sondern auch von der dynamischen Spannungsamplitude ab. Er ist deswegen nicht unbedingt von einer statischen Verstreckung unabhangig, wenn auchη konstant ist.
Dynamic Inversion via State Dependent Riccati Equation Approach: Application to Flight Vehicles

State Dependent Algebraic Riccati Equation (SDRE) technique is rapidly emerging as a design method, which provides a systematic and effective means of designing nonlinear controllers, observers and filters. This paper describes a new method of integrating the SDRE technique with the Dynamic Inversion control law that is frequently used in the design of aircraft control systems. This technique when applied to the design of a control system for a flight vehicle is shown to improve the stability and performance characteristics. Nomenclature ( φ θ ψ ) = Euler Angles of Rotation ( p q r ) = Angular Velocities ( U V W ) = Linear Velocities ( L M N ) = Generalized Moments ( Fx Fy Fz ) = Generalized Forces ( Jx Jy Jz Jxz ) = Moments of Inertia
Influence of different bird-driving modes on the behaviors of orchard pest birds

Playing back bird calls is an effective and noninvasive way to drive pest birds away from farms and orchards,and widely used in agriculture and fruit industry.However,little attention has been paid to assess the bird-driving effect of playing back bird calls and the bird response behaviors.In order to evaluate the effect of playing back bird calls on driving orchard pest birds,three bird-driving modes with playing back Accipiter gentilis calls,Pica pica scared calls,and Cyanopica cyana scared calls were set up in two cherry orchards in Haidian District of Beijing in May 2009,and an indoor experiment was conducted from April to May,2010 to examine the behavioral responses of the individuals of two main pest birds P.pica and C.cyana.The playback of A.gentilis calls could significantly reduce the population of P.pica in the cherry orchards(P0.05),and scare the C.cyana and Passer montanus.The pest birds had different behaviors to respond different bird-driving modes,and thus,it would be necessary to adopt comprehensive techniques and measure cost-profit efficiency,and to establish effective assessment mechanism in pest bird control management.
Dietary roughage regimen for feedlot steers: reduced roughage level (2%) during the mid-finishing period.

Because roughage in feedlot diets is one of the most expensive ingredients on an energy basis, regimens that minimize roughage usage are of interest. Crossbred steers of British breeds (n = 112, initial BW = 405 kg) were used to compare the feeding of diets containing 2% roughage from d 22 through 84 and 10% roughage from d 85 to finish (d 133; 2/10%) to the feeding of 10% roughage throughout the finishing period (10/10%); all diets were based on steam-flaked sorghum grain and contained monensin and tylosin. When the 2% roughage diet was fed, steers consumed less feed (6.8 vs 7.8 kg/d, P less than .01), tended to gain less (1.11 vs 1.20 kg/d, P = .13), and were numerically more efficient (16.5 vs 15.5 kg of gain/100 kg of DMI, P greater than .2) than steers fed the 10% roughage diet (10/10%). After the roughage content was increased from 2 to 10% on d 85 (all steers fed 10% roughage), steers fed the 2/10% regimen had greater DMI (8.4 vs 8.0 kg/d, P = .08) and ADG (1.29 vs 1.09 kg, P = .06), and tended to be more efficient (15.4 vs 13.6 kg of gain/100 kg of DMI, P = .10) than steers fed the 10/10% regimen. Steers fed the two regimens had similar (P greater than .2) overall gain performance. The 2/10% regimen tended to have a greater percentage of Choice carcasses (58 vs 42%, P = .14) and numerically more liver abscesses (24 vs 15%, P greater than .2) than the 10/10% regimen.(ABSTRACT TRUNCATED AT 250 WORDS)
Repositioning science reform efforts: Four practical recommendations from the field

Appeals to reform science education by policy makers are not new phenomena. To be sure, while science reform efforts have been ongoing occurrences for nearly six decades, perpetual educational refo...
Valvular Disease: Role of cardiac surgery support during contemporary TAVI.

The success of transcatheter aortic valve implantation (TAVI) is centred around the collaboration between cardiac surgeons and interventional cardiologists. A report from the German Quality Assurance Registry on TAVI now suggests that clinical outcomes in hospitals without cardiac surgery departments are similar to those in centres with onsite cardiac surgery support.
Chemistry and biology of hop flavonoids.

The flavonoids of hops include flavonol glycosides, condensed tannins, and prenylflavonoids. The first two flavonoid classes are located intracellularly, while the prenylflavonoids are secreted alo...
An Investigation of the Flow in Manifolds with Open and Closed Ends

The possibility of control of circulation around aircraft wings and gas turbine blades by ejection of air from the aerofoil into the main stream has drawn attention to the manifold problem. Discharge velocity distributions along the length of the wing or blade must be uniform, and it is important that the detailed nature of the flow in the supply manifolds should be understood. The distributions of velocity in manifolds supplying multicylinder internal combustion engines, in gas burners and in manifolds supplying canal locks are other allied problems.
The Need for Formal Surgical Global Health Programs and Improved Mission Trip Coordination.

Background There is a dire need for more surgical services as part of improving global health. Conditions treatable with surgery account for 11% of the global burden of disease, with a disproportionate burden affecting low- and middle-income countries (LMICs). Less than 6% of the world's operations are performed in LMICs, with relief organizations performing nearly 250,000 operations annually in LMICs in addition to each country's domestic surgical capacity. Currently, surgical needs are not adequately met by the existing patchwork of federal and nongovernmental organizations' surgical services and surgical mission trips. Improving coordination between mission trips may have synergistic benefits for maximizing the efficacy of the individual trips and improving the overall quality of care. Objectives To establish whether cooperation between surgical mission trips can lead to operational efficiency and to identify obstacles to cooperation. Methods In order to establish the veracity of cooperation translating into efficiency and to identify obstacles that prevent cooperation, a 50-question survey was created (see Supplement 1). The survey was sent to surgical program directors of the 147 major surgical programs in the United States and Canada with a follow-up telephone survey of 18 randomly selected programs. Findings The survey response rate was 14%. Although 90% of respondent programs mount at least 1 mission trip per year, only one-third confirmed the existence of global health or surgical global health programs at their institution (33%). There was significant interest in cooperating with programs at other institutions (80%). When asked why they do not communicate with humanitarian aid organizations doing similar work, 53% of respondents reported a "lack of knowledge of how to find similar organizations to mine doing similar work." An additional 21% of respondents were "unaware that coordination is possible." Conclusions A minority of respondent surgery programs host formal, organized surgical global health programs with a structured leadership based at academic medical centers. Although most institutions have individuals leading international humanitarian missions to LMICs, these leaders do not function in an integrated fashion with their departments, institutions, or other academic medical programs. The majority of respondents were interested in coordinating their surgical trips with other groups. Respondents suggested the creation of a central database that would allow trip organizers to share information about upcoming trips, site logistics, and personnel or supply needs.
Creating a contemporary clerkship curriculum: the flipped classroom model in emergency medicine.

The teaching modality of “flipping the classroom” has garnered recent attention in medical education. In this model, the lecture and homework components are reversed. The flipped classroom lends itself to more interaction in “class” and theoretically improved clinical decision-making. Data is lacking for this model for students in emergency medicine clerkships. We trialed the flipped classroom in our fourth-year student clerkship. Our aim was to learn student and faculty facilitator perceptions of the experience, as it has not been done previously in this setting. We evaluated this in two ways: (1) participant perception of the experience and (2) facilitator (EM physician educator) perception of student preparation, participation, and knowledge synthesis. With permission from its creators, we utilized an online video series derived from the Clerkship Directors in Emergency Medicine. Students were provided the link to these 1 week prior to the classroom experience as the “homework.” We developed patient cases generated from the videos that we discussed during class in small-group format. Afterward, students were surveyed about the experience using four-point Likert items and free-text comments and also were evaluated by the facilitator on a nine-point scale. Forty-six clerkship students participated. Students deemed the online modules useful at 2.9 (95 % CI 2.7–3.2). Further, they reported the in-class discussion to be of high value at 3.9 (95 % CI 3.8–4.0), much preferred the flipped classroom to traditional lecturing at 3.8 (95 % CI 3.6–3.9), and rated the overall experience highly at 3.8 (95 % CI 3.7–3.9). Based on preparation, participation, and knowledge synthesis, the facilitator judged participants favorably at 7.4 (95 % CI 7.0–7.8). Students commented that the interactivity, discussion, and medical decision-making were advantages of this format. Students found high value in the flipped classroom and prefer it to traditional lecturing, citing interactivity and discussion as the main reasons. The facilitator also viewed that the students were not only well prepared for the flipped classroom but that they also actively participated in and synthesized knowledge adequately during this experience. This study supports the use of the flipped classroom for EM clerkship students as a valuable, preferable teaching technique.
Sensitivity and Specificity of Metal Ion Levels in Predicting “Pseudotumors” due to Taper Corrosion in Patients With Dual Taper Modular Total Hip Arthroplasty

Abstract Background Currently, no serum metal ion threshold exists to identify adverse tissue reactions in total hip arthroplasty (THA) patients with taper corrosion. Our study aims to investigate the sensitivity and specificity of serum metal ions in detecting taper corrosion related pseudotumors in patients with dual taper modular THA. Methods A total of 148 patients with dual taper modular THA were investigated: (1) 90 patients with pseudotumors detected with metal artifact reduction sequence-magnetic resonance imaging (MARS-MRI) and (2) 58 patients without pseudotumors on MARS-MRI. Receiver operating characteristic curves were constructed to determine the sensitivity and specificity using different metal ion thresholds. The severity of intraoperative tissue damage was correlated with preoperative metal ion levels. Results Pseudotumor was associated with higher cobalt (5.0 μg/L vs 3.7 μg/L, P P P = .03). Conclusion Although metal ion levels alone should not be relied on as the sole parameter to determine revision surgery, cobalt level >2.8 μg/L and the Co/Cr ratio >3.8 are useful clinical diagnostic adjuncts in the systematic clinical evaluation for taper corrosion–related adverse tissue reactions in patients with dual modular taper THA.
Gamification of Apollo lunar exploration missions for learning engagement

Abstract The design, development, and evaluation of a serious game that gamifies the Apollo lunar exploration missions are presented. The gamification methodology and underlying implementation are motivated by the goal of game-based learning for youth and young adults and the intention to promote their interest in STEM learning. The game is a multidisciplinary composition that simulates a set of lunar roving activities including planning a traversing route, loading communication and science equipment onto the lunar rover, and driving the rover to explore the lunar surface. Accurate 3D terrains and spacecraft models are created and used in the game to maintain the high realism of the environment. Every gameplay step reflects real scientific procedures and behaviors that the astronauts performed in the past on the Moon. A usability study is conducted to gather feedback from a group of participants of different ages and with different game experience. The results of the study show the success of fostering great user engagement in STEM learning.
Aneurysms-Osteoarthritis Syndrome

Patient management by multidisciplinary team including clinical geneticists, cardiologists, orthopedic surgeons, radiologists, neurologists, vascular/cardiothoracic surgeons
An Open-Road Study of the Daytime Conspicuity Benefits of Fluorescent Bicyclist Apparel (Extended Abstract)

According to a 2016 NHTSA report (National Center for Statistics and Analysis, 2016) approximately 50,000 bicyclist injuries and 729 bicyclist fatalities were reported in the United States in the year 2014, with most crashes between motor vehicles and bicycles occuring during daylight hours. Most collisions between motor vehicles and bicyclists involve the bicyclist being struck from behind (Hutchinson & Lindsay, 2009; Kim, Kim, Ulfarsson, & Porrello, 2007). For this reason, it is important that bicyclists be sufficiently conspicuous to drivers who are approaching from behind.There has been a recent surge in research that applies basic perceptual science to make vulnerable road users more easily noticed by drivers. For example, humans’ perceptual sensitivity to biological motion (or “biomotion”; Johansson, 1973) can be used to enhance the conspicuity of pedestrians at night (for a review, see Tyrrell, Wood, Owens, Whetsel-Borzendowski, & Stafford-Sewall, 2016). Similar findings, using either retroreflecti...
The San Francisco Cancer Initiative: a community effort to reduce the population burden of cancer.

The great potential for reducing the cancer burden and cancer disparities through prevention and early detection is unrealized at the population level. A new community-based coalition, the San Fran...
Distributed voltage regulation using Volt-Var controls of a smart PV inverter in a smart grid: An experimental study

Abstract Distributed photovoltaic (PV) generator systems (especially rooftop PV) have been increasing significantly in electrical power systems. However, due to the variability of their output power, it is challenging to integrate large number of these PV generator systems into the existing electrical grid. These distributed PV generator systems can cause large voltage fluctuations due to the oscillation in their power output and reverse power flow in highly penetrated areas. While real power curtailment is an option to manage voltage issues, it reduces the production of this clean energy and is governed by policies and contracts. Traditionally, the use of reactive power to control voltage on a power grid is done through maintaining the voltage within a tolerable range by using transformer tap-changers (TPC), capacitor banks (CB), voltage regulators (VR), static synchronous compensator (STATCOM), and static Var compensators (SVC). Installation and maintenance costs of these devices can be quite high and some have relatively slow response times on the order of many seconds. A smart PV inverter can help regulate voltage by absorbing and injecting reactive power (Var) to/from the grid by using the Volt-Var control function. This paper presents an experimental analysis of the inverter Volt-Var control method for voltage regulation. The capacitive (i.e., Var injection) and inductive (i.e., Var absorption) effects of using a smart inverter and its ability to influence the voltage at the distribution level is investigated in this paper. When the smart PV inverter injects reactive power, it increases the distribution voltage. Conversely, voltage is reduced when the smart inverter absorbs reactive power. As a result, electric power utilities can control the distribution voltage without installing additional devices on the power network. The analyses from a field deployment under the Maui Advanced Solar Initiative Project in Hawaii is discussed here.
Pre-diagnosis plasma immune markers and risk of non-Hodgkin lymphoma in two prospective cohort studies

Inflammation and B-cell hyperactivation have been associated with non-Hodgkin lymphoma development. This prospective analysis aimed to further elucidate pre-diagnosis plasma immune marker profiles associated with non-Hodgkin lymphoma risk. We identified 598 incident lymphoma cases and 601 matched controls in Nurses' Health Study and Health Professionals Follow-up Study participants with archived pre-diagnosis plasma samples and measured 13 immune marker levels with multiplexed immunoassays. Using multivariable logistic regression we calculated Odds Ratios (OR) and 95% Confidence Intervals (CI) per standard deviation unit increase in biomarker concentration for risk of non-Hodgkin lymphoma and major histological subtype, stratifying additional models by years (<5, 5 to <10, ≥10) after blood draw. Soluble interleukin-2 receptor-α, CXC chemokine ligand 13, soluble CD30, and soluble tumor necrosis factor receptor-2 were individually positively associated, and B-cell activating factor of the tumor necrosis factor family inversely associated, with all non-Hodgkin lymphoma and one or more subtypes. The biomarker combinations associated independently with lymphoma varied somewhat by subtype and years after blood draw. Of note, the unexpected inverse association between B-cell activating factor and chronic lymphocytic leukemia/small lymphocytic lymphoma risk (OR: 95%CI: 0.51, 0.43-0.62) persisted more than ten years after blood draw (OR: 0.70; 95%CI: 0.52-0.93). In conclusion, immune activation precedes non-Hodgkin lymphoma diagnosis by several years. Decreased B-cell activating factor levels may denote nascent chronic lymphocytic leukemia many years pre-diagnosis.
Reliability-Based Structural Optimization Research at the University of Colorado: A Brief Retrospective 1983–1991

A brief retrospective of the past eight years of research efforts at the University of Colorado, Boulder, in reliability-based structural optimization (RBSO) is presented. This includes research related to (a) new formulations of both multi-limit state and multi-objective RBSO of steel and reinforced concrete structures, (b) use of interactive graphics in RBSO, (c) sensitivity of RBSO solutions to change in problem parameters, (d) RBSO of special structures such as large frames and bridges, (e) damage-tolerant RBSO, and (f) new probabilistic finite element formulations for nonlinear concrete structures.
The RSA Public Key Cryptosystem

The RSA (Rivest, Shamir, Adleman) cipher algorithm has captured the imagination of many mathematicians by its elegance and basic simplicity ever since it was introduced in 1978. Numerous descriptions of the algorithm have been published. Readers with a knowledge of a little basic number theory will find the original paper [RSA] by the inventors of the algorithm, Ronald L. Rivest, Adi Shamir, and Leonard M. Adleman, quite readable. Perhaps the most famous description is Martin Gardner’s expository article [G], which is written for readers of Scientific American. Martin E. Hellman [H] wrote another good Scientific American article describing the RSA algorithm and the knapsack cipher algorithm. The goal of this paper is to lead the reader who has some mathematical maturity but no knowledge of number theory, say a first year calculus student, a clever high school student, or an interested engineer, through the basic results needed to understand the RSA algorithm. The prerequisites are only a knowledge of the elementary school arithmetic of the integers, high school algebra, some familiarity with the notions of sets and of functions, and, most importantly, a real desire to understand how the RSA algorithm works. We begin with a discussion of general crypto systems and the differences between classical systems and public key systems. Then the treatment will give an informal but fairly rigorous introduction to the division algorithm, divisibility properties, greatest common divisors, the Euclidean algorithm, modular arithmetic, repeated squaring algorithm for b a (mod m), time estimates for these algorithms, Euler’s totient function, Euler’s Theorem, and, as a corollary, Fermat’s Little Theorem.
An Experimental Technique for Determination of Steam Fraction in Flowing Steam / Air Mixtures

An instrument has been developed to continuously measure the steam content in flowing steam/air mixtures. This instrument is nonintrusive and thus can be used in existing and proposed future experi...
Addressing Noncommunicable Disease in Dominican Republic: Barriers to Hypertension and Diabetes Care.

Introduction: Noncommunicable diseases (NCDs) significantly contribute to morbidity and mortality worldwide. During medical brigades in Santo Domingo, the Dominican Aid Society of Virginia (DASV) collects data to help understand the dynamics of NCD management. This study presents findings regarding resources and barriers to NCD treatment. Methods: A cross-sectional survey study was conducted in two communities (Los Mina and Paraiso) during the 2014 DASV summer brigade. Descriptive statistics, associations, correlations as well as qualitative analyses were conducted to better understand resources and barriers to care in relation to health care coverage. Results: More than one third (n = 64) of 165 individuals had hypertension and/or diabetes. Thirty-seven percent (Paraiso) and 46% (Los Mina) of study participants did not have health insurance in the previous year. For those that did have insurance, 77% (P) and 89% (LM) visited a physician in the previous year. In this same group, 65% of individuals from Paraiso reported that their health insurance never covered the cost of medications while only a quarter of individuals from Los Mina indicated this. Health insurance and access to physicians and medication varied depending on the community of residence. Surveys indicated that access to affordable medications was an important issue for participants. Also, even though individuals in Los Mina were less likely to have health insurance than those in Paraiso, they were more likely to visit a physician. Conclusion: This study contributes to a greater understanding of health care coverage and access for low-resource communities in the Dominican Republic. Health care access, insurance, and cost sharing differed between these communities, but barriers to care were common. Future investigations could focus on qualitative differences in communities' health insurance coverages and development of interventions to address obstacles to care.
The stability of step rate throughout a 3200 meter run

Abstract Step rate has been studied in controlled laboratory settings due to its association with biomechanical parameters related to running injuries. However, the stability of step rate in a run over ground when speed is not controlled remains unclear. In this observational cohort study, 30 subjects were asked to run 3200 meters (m) over ground at their self-selected pace during an Army Physical Fitness Test. Stationary cameras were placed along the paved course to capture step rate at 800 m, 1200 m, 1800 m, and 2200 m. For analysis of step rate at four different time points, a repeated measures analysis of variance (ANOVA) with a Bonferroni-Holm correction was utilized to determine statistical difference with a significance level set at p
Burn Severity and Post-Fire Erosion Control Affect Post-Fire Woody Plant Recruitment

As wildfires become more frequent and severe in the United States, effective post-fire intervention is increasingly important for soil and plant conservation. Erosion control is often necessary after wildfire, but methods vary in effectiveness and impacts on vegetation. Little is known about the effects of hydroseed, an erosion control product, on post-fire plant recovery trajectories. Hydroseed was applied to control erosion of sandy soils after the 2011 wildfire in the Lost Pines region of Texas. Pre-fire, the region was dominated by loblolly pine (Pinus taeda), an obligate-seeder, and resprouting oak species, including sand post oak (Quercus margaretta). We investigated the effects of hydroseed and burn severity on pine and oak recovery in Bastrop State Park, within the Lost Pines. Forty-six permanent plots were surveyed 1999–2015; hydroseed was applied to 15 plots post-fire. Hydroseed inhibited P. taeda regeneration in the first post-fire year but had no subsequent effect on P. taeda seedling numbers, and no effect on Q. margaretta resprout numbers in any year. P. taeda seedling numbers were greatest in lower burn severity plots in the first post-fire year and increased following high rain in 2015. Q. margaretta resprout numbers were greatest in higher burn severity plots in the first post-fire year only. Our results suggest that hydroseed may reduce initial post-fire pine recruitment but is unlikely to permanently alter long-term woody plant community recovery in this region; burn severity may be a more important factor. Further research is warranted to examine the effects of hydroseed on herbaceous plant communities.
Stochastic Optimization in Continuous Time: Stochastic Dynamic Programming

Introduction To solve a static, constrained optimization problem, we typically employ the Lagrange multiplier method. The solution to the problem is characterized by the first-order conditions of the Lagrange problem. To solve a stochastic, intertemporal optimization problem, the optimal control policy is characterized by the first-order conditions of the Bellman equation. In this chapter we shall introduce this method of dynamic optimization under uncertainty. One of the objectives is to make the reader feel as comfortable using the Bellman equation in dynamic models as using the Lagrange multiplier method in static models. The chapter begins with a one-sector optimal growth model. We go through the derivation of the corresponding Bellman equation step by step to convey the mathematical reasoning behind this powerful tool using a real economic problem, not an abstract mathematical formulation. Then we examine the mathematical structure of the stochastic optimization problem, including the existence of the optimal control, the differentiability of the value function, the transversality condition, and the verification theorem. More importantly, we summarize the Bellman equation in a cookbook fashion to make it easy to use. To illustrate, we apply the Bellman equation to several well-known models, such as portfolio selection, index bonds, exhaustible resources, adjustment costs, and life insurance. To make the presentation self-contained, we provide a brief introduction to each topic. Then, we extend the method from time-additive utility functions with a constant discount rate to a class of recursive utility functions.
Field-induced d x 2 -y 2 +id xy state and marginal stability of high-T c superconductors

It is shown that the complex d{sub xy} component is generated in a d-wave superconductor in the magnetic field. As one enters a superconducting state at the finite field the normal to superconducting transition occurs into the bulk d{sub x{sup 2}-y{sup 2}}+id{sub xy} state. The driving force for the transition is the linear coupling between the magnetic field and the nonzero magnetization of the d{sub x{sup 2}-y{sup 2}}+id{sub xy} condensate. The external magnetic field violates parity and time-reversal symmetries and the nodal quasiparticle states respond by generating the id{sub xy} component of the order parameter, with the magnitude estimated to be on the order of a few kelvin. Parity (P) and time-reversal (T) symmetries are violated in this state. (c) 2000 The American Physical Society.
Identification of a noncanonical RNA binding domain in the U2 snRNP protein SF3A1.

During splicing of pre-mRNA, 5' and 3' splice sites are brought within proximity by interactions between the pre-mRNA bound U1 and U2 snRNPs, followed by recruitment of the tri-snRNP for assembly of the mature spliceosome. Previously, we identified an interaction between the U2 snRNP-specific protein SF3A1 and the stem-loop 4 (SL4) of the U1 snRNA that occurs during the early steps of spliceosome assembly. Although harboring many annotated domains, SF3A1 lacks a canonical RNA binding domain. To identify the U1-SL4 binding region in SF3A1, we expressed amino- and carboxy-terminal deletion constructs using a HeLa cell-based cell free expression system. UV-crosslinking of the truncated proteins with 32P-U1-SL4 RNA identified the carboxy-terminal ubiquitin-like (UBL) domain of SF3A1 as the RNA binding region. Characterization of the interaction between SF3A1-UBL and U1-SL4 by electrophoretic mobility shift assay and surface plasmon resonance determined high binding affinity (K D = ∼97 nM), and revealed the double-stranded G-C rich stem of U1-SL4 as an important feature for binding to the UBL domain. Further, mutations of two conserved tyrosine residues, Y772 and Y773, were found to cause a two- and fivefold decrease in the binding affinity for U1-SL4, respectively. Finally, we found that SF3A1-UBL can specifically pull down the U1 snRNP from HeLa nuclear extract, demonstrating its capacity to bind U1-SL4 in the context of the intact snRNP. Thus, the data show that the UBL domain of SF3A1 can function as an RNA binding domain and that mutations in this region may interfere with U1-SL4 binding.
Latent Variable Regression for Process and Quality Modeling

The supervised learning methods, partial least squares (PLS) and canonical correlation analysis (CCA), have been widely used in industrial processes to perform multivariate statistical modeling and monitoring based on process variables and quality variables. However, the latent variables extracted by PLS may contain irrelevant components, while CCA focuses only on the correlation but ignores the variance information. To overcome their drawbacks, a latent variable regression (LVR) modeling method with regularization is proposed to retain the prediction efficiency of CCA while exploiting the quality variance structure. LVR minimizes the prediction error between input and output scores, and retains consistent objectives in inner and outer modeling. Synthetic case studies and the Tennessee Eastman process are used to demonstrate the effectiveness of the proposed algorithm.
Image Synthesis with a Single (Robust) Classifier

We show that the basic classification framework alone can be used to tackle some of the most challenging tasks in image synthesis. In contrast to other state-of-the-art approaches, the toolkit we develop is rather minimal: it uses a single, off-the-shelf classifier for all these tasks. The crux of our approach is that we train this classifier to be adversarially robust. It turns out that adversarial robustness is precisely what we need to directly manipulate salient features of the input. Overall, our findings demonstrate the utility of robustness in the broader machine learning context.
Concussion-Prevention Strategies Used in National Collegiate Athletic Association Divisions I and II Women's Soccer

Context Whereas much attention has been paid to identifying mechanisms for decreasing concussion rates in women's soccer players, which strategies are currently being used is unknown. In addition, athletic trainers' (ATs') knowledge and beliefs about the efficacy of concussion-prevention practices have not been studied. Objectives To evaluate the concussion-prevention strategies being used in National Collegiate Athletic Association Division I and Division II women's soccer and identify the beliefs of certified ATs regarding mechanisms for preventing concussion. Design Cross-sectional study. Setting Online survey. Patients or other participants A total of 223 women's soccer team ATs employed at Division I or II universities. Main outcome measure(s) A survey instrument of structured questions and open-ended, follow-up questions was developed to identify the use of cervical-strengthening programs, headgear, and other techniques for preventing concussion. Questions also addressed ATs' beliefs regarding the effectiveness of cervical strengthening, headgear, and mouthguards in concussion prevention. Data were collected via questionnaire in Qualtrics survey software. Descriptive statistics of frequencies and percentages were calculated for close-ended questions. Open-ended questions were evaluated for common themes, which were then reported by response frequency. Results Cervical strengthening or stability for concussion prevention was reported by 38 (17.12%) respondents; 153 (69.86%) ATs believed that cervical strengthening would aid in concussion prevention. Seventy-eight (35.49%) reported that their players wore headgear. Nineteen (8.76%) believed that soccer headgear prevented concussions; 45 (20.74%) believed that mouthguards prevented concussions. Education in proper soccer technique was reported by 151 (69.59%) respondents. Fourteen (0.06%) respondents cited nutritional strategies for concussion prevention. Conclusions Although ATs believed that cervical strengthening could help prevent concussions, few had implemented this strategy. However, the ATs whose teams used headgear outnumbered those who believed that headgear was an effective prevention strategy. Based on our findings, we saw a disconnect among the current use of concussion-prevention strategies, ATs' beliefs, and the available evidence.
End-to-end Bayesian analysis of 14C dates reveals new insights into lowland Maya demography

Archaeologists and demographers increasingly employ aggregations of published radiocarbon (14C dates) as demographic proxies summarizing changes in human activity in past societies. Presently, summed probability densities (SPDs) of calibrated radiocarbon dates are the dominant method of using 14C dates to reconstruct demographic trends. Unfortunately, SPDs are incapable of converging on their true generating distributions even as the number of observations gets large. To overcome this problem, we propose a more principled alternative that combines finite mixture models and Bayesian inference to identify the generating distribution of a set of radiocarbon dates. Numerical simulations and an assessment of the statistical identifiability of our method demonstrate that it correctly converges on the generating distribution. We apply this novel end-to-end Bayesian approach to reconstruct prehistoric Maya demographic growth using a recently compiled Mesoamerican radiocarbon database. Our results show that the Maya Lowlands experienced a century of rapid growth rates (~1%) during the Late Classic, followed by a rapid decrease in population during the Terminal Classic, and a subsequent more-modest resurgence in population during the Postclassic. Additionally, a detailed population reconstruction of the important political center of Tikal verifies that slow population growth between the Preclassic and Early Classic gave pace to rapid growth starting around AD 500 and peaking at the beginning of the eight century. Our proposed method verifies previous reconstructions based on settlement patterns and ceramics, but with far more precise time-resolution and characterization of uncertainty than has been possible.
Climate Variability Diagnosed from the Spherical Coordinates

The spherical coordinates are commonly used in oceanography; in particular, most climate studies and datasets are based on the z-coordinate. Therefore, in the first part of this chapter we examine the climate variability using the z-coordinate; at the end of this chapter, we will also explore using longitudinal and latitudinal coordinates to diagnose the climate variability.