cssi/SciSciGPT-SciSciNet huggingface dataset:
Modifications to the sliding-window kernel RLS algorithm for time-varying nonlinear systems: Online resizing of the kernel matrix

A kernel-based recursive least-squares algorithm that implements a fixed size “sliding-window” technique has been recently proposed for fast adaptive nonlinear filtering applications. We propose a methodology of resizing the kernel matrix to assist in system identification of time-varying nonlinear systems. To be applicable in practice, the modified algorithm must preserve its ability to operate online. Given a bound on the maximum kernel matrix size, we define the set of all obtainable sizes as the resizing range. We then propose a simple online technique that resizes the kernel matrix within the resizing range. The modified algorithm is applied to the nonlinear system identification problem that was used to evaluate the original algorithm. Results show that an increase in performance is achieved without increasing the original algorithm's computation time.
Solid mercury dihydride: mercurophilic bonding in molecular HgH(2) polymers

Atomic mercury subjected to mercury arc irradiation reacts in solid hydrogen to give the linear HgH(2) molecule with strong IR absorptions at 1902 and 773 cm(-1). Annealing leads to HgH(2) dimer and trimer, and warming above 7 K allows the hydrogen matrix to sublime and solid HgH(2) to form. This covalent molecular solid is characterized by strong IR absorptions at 1802 and 673 cm(-1) and by decomposition at 150-170 K.
Spectrum of a one-atom laser in photonic crystals

The emission spectrum of a single-emitter laser in a photonic crystal is presented. We consider a coherently pumped two-level emitter strongly coupled to a high-quality microcavity engineered within a photonic crystal. We show that the cavity spectrum consists of both elastic and inelastic components, for which we derive analytical expressions. Our study reveals enhanced, spectrally narrower emission resulting from the radiation reservoir of the photonic crystal. The cavity field spectral characteristics are fundamentally distinct from those of a corresponding microcavity in ordinary vacuum. At high pump intensities and for large discontinuities in the photon density of states between Mollow spectral components of atomic resonance fluorescence, the emitted intensity originating from the elastic spectral component increases with the intensity of the pump and the elastic component dominates the spectrum. In the case of a vanishing photon density of states in the spectral range surrounding the lower Mollow sideband and no dipolar dephasing, the cavity spectrum is elastic.
NUCLEAR-CYTOPLASMIC RELATIONSHIPS IN HUMAN CELLS IN TISSUE CULTURE V. A Method for Embedding Enucleate Cytoplasm for Electron Microscopy

Several methods have been developed for in situ embedding of tissue culture cells grown on glass. Borysko and Sapranauskas (1) first reported a technic for embedding whole colonies of cells for sectioning in a plane perpendicular to the glass surface. Howatson and Almeida (2), using a modification of Gay's method for smears (3), embedded cells by inverting gelatin capsules, filled with partially polymerized methacrylate, over selected areas of the slide, producing blocks which could be sectioned parallel to the surface of the glass. The procedures described by Nebel and Minick (4) and by Bloom (5) allow more accurate orientation of capsules over specific cells, but are limited by their equipment to embedding only one field of cells at a time. Nishiura and Rangan (6) recently described a stand constructed for embedding multiple sites with some degree of specificity, and Lat ta (7) developed a method allowing selection of completely random sites for embedding cultures grown in Petri dishes. Studies by electron microscopy on the effects of enucleation on the morphologic structure of cytoplasm required modification of these methods to permit more flexible independent positioning of small capsules for simultaneous embedding of a number of randomly distributed single enucleate fragments. As many as 15 to 20 fragments can be produced in one culture vessel (8, 9), but for orientation in sectioning only 1 or 2 should be embedded per capsule. The technic described in this report utilizes No. 4 gelatin capsules and a magnetic mounting holder. I t allows rapid, accurate location and embedding of single cells or fragments in as many as eight capsules per culture.
Silicate Cooling Model Fits to Galileo NIMS Data of Volcanism on Io

The Near Infrared Mapping Spectrometer (NIMS) has obtained spectra of volcanoes on the surface of the jovian satellite Io.
Performance evaluation of CSMA/CA with multiple-variable contention window

In this paper, we first study the impact of non-zero packet error rates caused by corruption in a radio channel on the packet retransmission probability and system throughput known from the literature, which mostly considers only packet collisions, and provide a revised mathematical expression. Then, using the new throughput expression for a one-station system, we approximately relate the actual station throughput with the normalized station throughput in terms of packet-available probability for a specific traffic type, particularly, when packets of different lengths are used for transmission through a channel with non-zero packet error rates under the CSMA/CA backoff procedure with a multiple-variable contention window.
Anomalous diffusion resulting from strongly asymmetric random walks

for leftward and rightward flights: PL(t);t 2m and PR(t);t 2h , with mfih. We calculate the dependence of the variance exponent g (s 2 ;t g ) on the PDF exponents n, m, and h. We find thatg is determined by the two smaller of the three PDF exponents, and in some cases by only the smallest. A PDF with decay exponent less
Teach Them When They Aren't Looking: Introducing Security in CS1

This article discusses computer security exercises that have been used to introduce concepts in foundational computer-programming courses. It presents two examples and discusses the associated reactions of the students as they learn about computer security at the beginning of their computer-programming careers.
COMPOUND AUTOSOMES IN DROSOPHILA MELANOGASTER: THE MEIOTIC BEHAVIOR OF COMPOUND THIRDS

Studies of the meiotic distribution of compound-3 chromosomes in males and females of Drosophila melanogaster provided the following results. (1) From females homozygous for the standard arrangement of all chromosomes other than C(3L) and C(3R), less than 5% of the gametes recovered were nullosomic or disomic for compound-3 chromosomes. The frequency of nonsegregation differed between strains, but within a given strain it remained relatively constant. (2) According to egg-hatch frequencies, C(3L) and C(3R) segregate independently during spermatogenesis. (3) In females, structurally heterozygous second chromosomes occasion a marked increase in the recovery of nonsegregational progeny; in males, rearranged seconds have no apparent influence on the distribution of compound thirds. (4) The highest frequencies of nonsegregational progeny were recovered from C(3L);C(3R) females carrying compound-X (plus free Y) chromosomes. (5) In comparing the recovery of nonsegregating compound thirds to the recovery of rearranged heterologs, a definite nonrandom distribution was realized in several crosses. These results are examined in reference to the concepts of distributive pairing (Grell 1962). Moreover, considering the structural nature of compound autosomes, we propose that nonhomologous (distributive) pairing is a property of the centromeric region and suggest that rearrangements involving breaks in this region possibly alter the effectiveness of distributive pairing forces.
Vasoregulation by the β1 subunit of the calcium-activated potassium channel

Small arteries exhibit tone, a partially contracted state that is an important determinant of blood pressure. In arterial smooth muscle cells, intracellular calcium paradoxically controls both contraction and relaxation. The mechanisms by which calcium can differentially regulate diverse physiological responses within a single cell remain unresolved. Calcium-dependent relaxation is mediated by local calcium release from the sarcoplasmic reticulum. These 'calcium sparks' activate calcium-dependent potassium (BK) channels comprised of alpha and beta1 subunits. Here we show that targeted deletion of the gene for the beta1 subunit leads to a decrease in the calcium sensitivity of BK channels, a reduction in functional coupling of calcium sparks to BK channel activation, and increases in arterial tone and blood pressure. The beta1 subunit of the BK channel, by tuning the channel's calcium sensitivity, is a key molecular component in translating calcium signals to the central physiological function of vasoregulation.
DYNAMIC PRESSURE RISE IN THE DRYING CHAMBER AS A REMOTE SENSING METHOD FOR MONITORING THE TEMPERATURE OF THE PRODUCT DURING THE PRIMARY DRYING STAGE OF FREEZE DRYING

Abstract A novel dynamic pressure rise method is developed as a remote sensing procedure for determining at different times during the primary drying stage of the freeze drying process (i) the temperature of the moving interface between the dried and frozen layers of the product, (ii) temperature close to the upper surface of the dried layer of the product, (iii) the temperature of the bottom surface of the frozen layer of the product, and (iv) the temperature profile of the frozen layer of the product. Furthermore, by knowing the temperature of the heating plate and determining the value of the temperature of the moving interface from the dynamic pressure rise method, the value of the position of the moving interface could be determined by an expression presented in this work
The misunderstood child: the child with a nonverbal learning disorder.

issues and purpose. To introduce nurses to the characteristics of nonverbal learning disorders (NLD) and their psychosocial trajectory in children. Despite the prevalence of learning disorders in children, few nursing professionals are familiar with NLD and their manifestations. conclusions. The child with NLD faces unique challenges in the social, academic, visual-spatial, motoric, and emotional spheres. practice implications. Nurses can play a vital role in the identification, education, and provision of resources for these children.
Male zebra finches can learn male-typical vocalizations from hormone-treated female tutors

Abstract Male zebra finches, Taeniopygia guttata , produce two learned vocalizations: song and ‘long’ (or ‘distance’) calls. Females do not sing and their long calls are not learned. Males learn their vocalizations during development by imitating the vocalizations of adult males, and do not typically imitate the vocalizations of females. The goal of this study was to examine the rules governing tutor choice that ensure that young males learn only the vocalizations of males. Two singing males were each paired with a female that had been treated with oestradiol during development so that the female sang and produced male-typical long calls in adulthood. Each pair was given successive cohorts of foster chicks to raise. In adulthood, the vocalizations of the foster sons were recorded and compared with those of their foster parents. Foster sons copied the song of one foster parent only. They were as likely to copy from their female as from their male parent. No association was seen between the choice of song and long-call tutors. These results show that adult females that produce male-typical vocalizations can be equally good vocal tutors as males, and that young males can independently choose their song tutor and long-call tutor.
Does “Telling” Less Protect More? Relationships Among Age, Information Disclosure, and What Children with Cancer See and Feel

Parents report telling young children less about the diagnosis, treatment, and prognosis of cancer than older children and adolescents. This is often based on the desire to spare children from being overwhelmed. 43 children diagnosed with cancer reported on information disclosed to them at diagnosis, their causal attributions, illness-related stress, and coping strategies. Consistent with parental reports, children under 9 years (n = 18) were told less than children 9-14 years (n = 15) and adolescents (n = 10). Young children's reports of illness impact differed from older children and adolescents only with respect to school and social domains. Younger children reported fewer cognitive strategies than older children and adolescents. Even though young children were told much less than older children they reported similar levels of distress. This suggests that nondisclosure fails to mask the salient and distressing aspects of the illness.
POSTDATE PREGNANCY Part II. Clinical Implications

This is the second part of a paper on management of the postdate pregnancy. The first part, a comprehensive review of the literature, forms the foundation for this clinical research. Data from 175 consecutive deliveries with the Yale Nurse-Midwifery Practice are presented, with specific emphasis on gestational age and infant outcome measures. Postdate pregnancy (exceeding 42 weeks' menstrual age) occurred in 10.3%, while the incidence of postmaturity was 1.7%. Certain complications such as fetal distress and meconium aspiration are significantly more common for the postdate infant, and it is more likely that the postdate gravida will have experienced prenatal bleeding and will need oxytocin stimulation in labor. A management protocol of fetal evaluation is proposed. At 41.5 weeks, daily fetal movement assessment is begun. At 42 weeks, a nipple stimulation contraction stress test and an ultrasonic biophysical profile are suggested. Routine labor induction on the basis of dates alone is discouraged.
Computational science certificates for the current workforce: lessons learned

One of the keys to the future competitiveness of U. S. industry is the integration of modeling and simulation into the development, design, and manufacturing process. A related challenge is to retrain the current workforce in the use of computational modeling to enable its effective use in the workplace. We review our implementation of a new, computational science certificate program aimed at the current workforce in Ohio. The structure of the current program is discussed along with the problems associated with meeting the educational needs of this population.
Encounters of Golden Eagles banded in the Rocky Mountain West

Abstract Golden Eagles (Aquila chrysaetos) were banded as nestlings, migrants, wintering birds, and resident breeders in three states of the U.S. Rocky Mountain West between June 1973 and January 1999. To January 2000, 6.2% of 325 eagles banded had been encountered as dead or injured birds or live captures. Median age of all encounters was 2.25 yr. Sex ratio of Golden Eagles encountered was not different from sex ratio at banding. Eagles banded as migrants were encountered less frequently than those banded as nestlings, residents, or wintering eagles. Cumulative exponential distribution analysis of recoveries (dead eagles) by age indicated 50% of banded eagles were dead by 2 yr, 7 mo, 75% by age 5 yr, 1 mo, and 95% by 11 yr, 1 mo, with a maximum predicted age of 33 yr, 10 mo. Distance from banding to encounter site was <90 km for 90% of encounters, and all encounters of eagles banded as nestlings were within 200 km of their natal nest. Mean vector bearing of all encounters was 92.95°. Rayleigh tests for u...
Advances in neonatal cardiac surgery: recent advances, the low-hanging fruit, what is on the horizon and the next moonshot

Purpose of review To review the recent advances in neonatal cardiac surgery and identify future directions of this subspecialty of congenital heart surgery. Recent findings Recent advances in neonatal cardiac surgery have included the right ventricular to pulmonary artery conduit, the hybrid procedure and antegrade cerebral perfusion. In addition to refining the indications and techniques for these strategies, we can advance the field through collaborative learning between neonatal heart surgery centers. Collaborative learning is the low-hanging fruit that we can all use to advance the care of this patient population. On the horizon are a variety of strategies that will improve our management of this complex patient population. Among these improvements are better anticoagulation strategies targeting the unique hemostatic system of the neonate. The next transformative change, the next moonshot, may well be regenerative therapy that unlocks the body's ability to regenerate specific tissue such as valves and heart muscle to correct congenital defects and repair damaged muscle. Summary The current state of the specialty of neonatal cardiac surgery will be reviewed, and the possible future directions based on their ease and likelihood: specifically, the low-hanging fruit, what is on the horizon and the next moonshot.
Competitive distribution estimation: why is Good-Turing good

Estimating distributions over large alphabets is a fundamental machine-learning tenet. Yet no method is known to estimate all distributions well. For example, add-constant estimators are nearly min-max optimal but often perform poorly in practice, and practical estimators such as absolute discounting, Jelinek-Mercer, and Good-Turing are not known to be near optimal for essentially any distribution. We describe the first universally near-optimal probability estimators. For every discrete distribution, they are provably nearly the best in the following two competitive ways. First they estimate every distribution nearly as well as the best estimator designed with prior knowledge of the distribution up to a permutation. Second, they estimate every distribution nearly as well as the best estimator designed with prior knowledge of the exact distribution, but as all natural estimators, restricted to assign the same probability to all symbols appearing the same number of times. Specifically, for distributions over k symbols and n samples, we show that for both comparisons, a simple variant of Good-Turing estimator is always within KL divergence of (3 + on(1))/n1/3 from the best estimator, and that a more involved estimator is within On(min(k/n, 1/√n)). Conversely, we show that any estimator must have a KL divergence at least Ωn(min(k/n, 1/n2/3)) over the best estimator for the first comparison, and at least Ωn(min(k/n, 1/√n)) for the second.
Radiation and breast reconstruction: Algorithmic approach and evidence-based outcomes

Postmastectomy radiation (PMRT) in the setting of immediate breast reconstruction has been associated with increased complications and poorer aesthetic outcomes for both autologous and implant reconstructions. Many centers have attempted to mitigate the deleterious effects associated with radiation by implementing an algorithmic approach to breast reconstruction. Although the literature regarding the optimal timing of radiotherapy and breast reconstruction remains controversial, reported outcomes following various algorithms have been encouraging and warrant further consideration. J. Surg. Oncol. 2016;113:906-912. © 2016 Wiley Periodicals, Inc.
Final Technical Report: Electronic Structure Workshop (ES13)

The 25th Annual Workshop on Recent Developments in Electronic Structure Methods (ES2013) was successfully held at the College of William & Mary in Williamsburg VA on June 11-14, 2013. The workshop website is at http://es13.wm.edu/ , which contains updated information on the workshop and a permanent archive of the scientific contents. DOE's continued support has been instrumental to the success of the workshop.
Parasitoid‐induced transgenerational fecundity compensation in an aphid

Increased reproductive effort by organisms in response to attack by consumers (‘fecundity compensation’) is well documented in both plants and animals, although most examples only involve direct compensation by the individuals exposed to consumers. We used the parasitoid wasp Lysiphlebus orientalis Starý & Rakhshani (Hymenoptera: Braconidae) and the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), to determine whether reproduction by parasitized aphids can lead to fecundity compensation. Although parasitism by L. orientalis strongly decreased fecundity for parasitized aphids, offspring of parasitized aphids reproduced at a greater rate at maturity than did the offspring of non-parasitized aphids. Also, parasitized aphids contained fewer but larger embryos developing within them. The presence of these larger embryos may explain how the offspring of parasitized aphids can produce more progeny with no apparent reduction in progeny quality. Mature and nearly mature soybean aphids successfully reproduced after parasitism, a prerequisite for transgenerational fecundity compensation, and L. orientalis showed a preference for these age classes of aphids as hosts when foraging. Transgenerational fecundity compensation may allow for higher than expected densities of both hosts and consumers to persist and may be adaptive for both the host and consumer in this system. The phenomenon could also reduce the strength of biological control interactions.
1 Using Futility Study Designs and Sample Size Calculations to Improve Early Laboratory Studies

Futility designs have been used in Phase II human studies in cancer research for over thirty years. More recently the same designs have been applied in Phase II human studies in neurology. There has been little, if any application of these designs to laboratory studies. For initial laboratory experiments the sample size is often chosen as an n of 5, increasing the n a few more depending on observed results. Futility studies provide a more rigorous approach to determining the initial sample size for an experiment. To apply a futility design, investigators must have some knowledge of historical control rates in similar experiments in their laboratory, and must be able to specify the magnitude of an effect that would make an experiment worthwhile to pursue further. Using a futility approach to plan an initial laboratory study could reduce the chance of missing important effects that should be carried forward into more comprehensive experiments, and could reduce the chance of carrying forward experiments that have little likelihood of success. This session will present the concept of futility studies, provide laboratory-based examples, and discuss sample size calculation. At the end of the session participants should understand the concept of futility, be able to use standard software for sample size calculation, and be able to plan their own studies using a futility approach.
Information Displays for Medical Diagnosis

The Proximity Compatibility Principle (PCP) states that a display format is well-suited to a given task if the information sources in the display are related to the same degree as information sources in the task. While experiments have shown that PCP can provide useful display design guidelines for many types of tasks, diagnosis tasks have not seemed to conform to PCP's predictions. The current experiment compared performance with integral, configural, and separable displays in three diagnosis tasks based on a medical diagnosis technique. As predicted, the integral display allowed the best performance. The results indicate that PCP is a useful theory for diagnosis tasks, but different diagnosis tasks can differ widely in their task demands.
Acute kidney injury: Clinical trials in AKI: is the end in sight?

Clinical trials in patients with acute kidney injury (AKI) have been stymied by a lack of consensus on suitable renal-specific end points. In a recent analysis, Grams et al. suggest that a sustained 30–40% reduction in estimated glomerular filtration rate after hospital discharge might be a suitable intermediate end point for AKI clinical trials.
Diagnosis of Autism

The identification and assessment process for children with autism and autistic spectrum disorder is reviewed by a developmental pediatrician, speech and language therapist, and consultant in pediatric disability at Guy’s and St Thomas’ Hospitals, and Great Ormond Street Children’s Hospital, London, UK.
Meeting the Challenge of Measuring Communication Exposure in the Digital Age

ABSTRACTThis article offers two predictions about less and more promising ways to move forward in efforts to measure communication exposure in the digital age. First, I argue that people will be increasingly unable to recall and accurately report on the source of their information exposure in surveys, although they have never been very good at this to begin with. Many surveys seeking to gauge media processes and effects continue to assume respondents' abilities to identify and recall the precise source of information exposure, but the speed, dynamism and participatory nature of media diffusion in the digital age will render these recollections less meaningful than ever before. Second, I suggest that researchers should consider making more effective use of time as a critical source of variation in efforts to gauge communication exposure moving forward. Specifically, research designs that are able to accurately capture large-scale changes in the availability of specific media messages over time, and link th...
Evaluation of a new domestic reagent for detection of HIV-1 viral load

Objective To evaluate the application of a new domestic high- precision magnetic HIV PCR fluormetric diagostic kit in detecting the HIV viral load. Methods A total of 219 plasma samples were collected from HIV- 1/AIDS individuals for detecting RNA viral load with Roche COBAS TAQMAN48 and a domestic reagent. The detection results of the two reagents were compared. Results There was a linear relation between the viral load revealed by the two reagents, and the distributions of the high, middle and low viral load were not significantly different. The results were not consistent within the viral load range from log3 to log4. Conclusions The gap between the new domestic diagnostic regent and Roche COBAS TAQMAN48in detection performance is narrowing although the regent needs to be improved in sensitivity for detecting low viral load and stability for middle viral load.
Development of a Duplex Ultrasound Simulator and Preliminary Validation of Velocity Measurements in Carotid Artery Models.

Objective:Duplex ultrasound scanning with B-mode imaging and both color Doppler and Doppler spectral waveforms is relied upon for diagnosis of vascular pathology and selection of patients for furth...
Predicting Zika virus structural biology: Challenges and opportunities for intervention

BackgroundZika virus is an emerging crisis as infection is implicated in severe neurological disorders—Guillain–Barre syndrome and fetal microcephaly. There are currently no treatment options available for Zika virus infection. This virus is part of the flavivirus genus and closely related to Dengue Fever Virus, West Nile Virus, and Japanese Encephalitis Virus. Like other flaviviruses, the Zika virus genome encodes three structural proteins (capsid, precursor membrane, and envelope) and seven nonstructural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5). Currently, no structural information exists on these viral proteins to facilitate vaccine design and rational drug discovery.MethodsStructures for all Zika virus viral proteins were predicted using experimental templates available from closely related viruses using the online SwissModel server. These homology models were compared to drug targets from other viruses using Visual Molecular Dynamics Multiseq software. Sequential alignment of all Zika vir...
Alcohol Withdrawal: Treatment and Application

Severe alcohol withdrawal has a significant morbidity and mortality rate, especially with a pre-existing co-morbid state. Repeated alcohol withdrawal episodes may sensitize the patient, making future episodes more severe and harder to treat. Benzodiazepines have been found to be safe and effective in the treatment of alcohol withdrawal. However, their abuse liability, their cross-tolerance with alcohol, and the increased risk of relapse to other drugs of abuse limit their use in outpatient settings. The authors discuss some of the neuropharmacological aspects of alcohol withdrawal and drug treatment options with a focus on anticonvulsant drugs. Medications such as sodium valproate, carbamazepine, gabapentin, and topiramate are discussed and their role in the clinical setting addressed. Finally, the authors discuss the potential utility of newer approaches in managing anxiety associated with alcohol withdrawal, such as the use of neurosteroids.
Infections, Inflammogens, and Drugs.

This chapter examines environmental inflammatory factors in vascular disease and dementia with a focus on infections, environmental inflammogens, and drugs that modulate both vascular disease and dementia. Infections and blood levels of inflammatory proteins are risk factors for future coronary events and possibly for dementia. When early age mortality is high, the survivors carry long-term infections that impair growth and accelerate mortality at later ages (“cohort morbidity phenotype”). Chronic infections, which are endured by most of the world's human and animal populations, cause energy reallocation for host defense. Infections and inflammation may impair stem cell generation, with consequences to arterial and brain aging. Diet may introduce glycotoxins that stimulate inflammation. Some anti-inflammatory and anti-coagulant drugs may protect against coronary artery disease and certain cancers, and possibly also for Alzheimer disease. These “pharmacopleiotropies” implicate shared mechanisms in diverse diseases of aging.
Minimization of transceiver energy consumption in wireless sensor networks with AWGN channels

In this paper, we determine how to minimize energy consumption per information bit in a single link, with the consideration of packet retransmission and overhead. This is achieved by deriving expressions for the optimum target bit error probability and packet length at different transmission distances. Furthermore, the energy consumptions of different modulation schemes are compared over an additive white Gaussian noise (AWGN) channel. Finally, it is shown that the optimum target bit error probability and packet length converge to a constant value for long distances. Numerical results show that at short distances, it is optimum to use bandwidth efficient modulation with large packets and low target BER, and at long distances, it is optimum to use energy efficient modulation with short packets and high target BER.
Does Marital Status of Parents Relate to Family Communication Regarding Finances

How do youth and parents perceive their communication with each other? How do they perceive communication about money with each other? Are there differences between married-parent families and single-parent families? The reported study examined the discrepancies in perception between parents and youth and compares these differences between married and single-parent families. Although single-parent families had greater discrepancies in perceptions regarding communication in general, there was no evidence of such differences in discrepancies regarding communication about money. The finding suggests the importance of youth development programs to provide information and encouragement to both youth and their parents.
Laser Spectroscopy inside Inhomogeneously Broadened Lines

Spectral lines in solids are often inhomogeneously broadened at low temperatures and this obscures important information such as the homogeneous linewidth, hyperfine structure, ion-pair interactions and tunneling splittings. We describe the use of frequency domain (e.g., spectral holeburning) and time domain (e.g., photon-echo, optical free induction decay (FID) and quantum beat) techniques to eliminate the effects of inhomogeneous broadening. in this way spectral resolution can he increased by three to eight orders of magnitude. These techniques are illustrated by numerous examples taken from the fn → fn spectroscopy of trivalent rare-earth ions doped into insulating solids. For metastable levels at low temperatures homogeneous linewidths of ~1–10 kHz, can be measured. Mechanisms responsible for spectral holeburning arc classified according to the level which stores population in the bleaching process. We discuss the almost universal role of fluctuations of host-lattice nuclear spins in determining the homogeneous linewidths of metastable optical levels at low temperatures (T < 4K), and point out that the dynamics of these nuclear spins are strongly modified by the presence of the rare-earth ions. The result is a spread of nuclear spin fluctuation times (10-5 – 10-2 sec.) which causes spectral diffusion resulting in non-exponential photon-echo decays and time dependent holewidths. Another consequence of spectral diffusion is that the measurement of the “homogeneous linewidth” by photon echo or FID, and holeburning techniques can give different values in apparent contradiction. The difference, however, is due to the different time scale of the two measurements with respect to the nuclear spin-flip times. The use of sharp probes such as spectral holes to sensitively measure small splittings and the effect of external perturbations is also illustrated.
Dynamic fracture mechanics in rocks with application to drilling and perforation

Abstract The dynamic failure analyses of rocks have long been the subject of intensive studies in mining, oil and gas, and civil engineering industries. Dynamic failures in rocks are associated with high rate loads with high dynamic energy densities. The perforation, drilling, and mine blasting of rocks are a few examples in which dynamic failure simulation technologies are essential for a successful design. For example, in the case of drilling, accurately estimating the dissipated mechanical energies for the bit is critical in design optimization of drill bit configurations. Each individual cutter in a bit configuration applies frequent impacts during rock/cutter interactions that induce stress waves into the rock skeleton. Dynamic failure simulation of rocks during rock/cutter interaction helps designers to estimate the dissipated mechanical energies. The failure mechanisms of rock are initiated from microscale flaws within the rock skeleton, that is, microcracking and/or microvoiding, and eventually macroscale cracks are formed upon coalescence of microflaws. Thus, the failure mechanisms of rock are multiscale phenomena which strongly depend on hydromechanical properties, porosity, permeability, pore pressure, confining pressure, applied loading rates, and temperature level in rocks. In this chapter, emphasis is put on dynamic energy density effect on failure mechanisms in rocks. Dynamic fracture mechanics account for the effect of both compressive and tensile propagated stress waves on fracture mechanics of rocks. The propagation of tensile cracks can be influenced; in particular, by the reflected tensile wave from the free surfaces that accelerates the propagation of tensile cracks. A continuum damage mechanics (CDM) model is discussed in this chapter that takes into account the effect of dynamic energy densities. Finite-element analysis (FEA) is a standard numerical tool in simulating the nonlinear behaviors of rocks, and it is considered herein to include the effects of strain rate and dynamic energy density on the rock strength. Combinations of FEA together with dynamic CDM models can successfully capture progressive dynamic failure mechanisms in heterogeneous rock skeleton. Such prediction techniques for the failure mechanisms of rocks are discussed in this chapter.
Structural, tribological, and mechanical properties of the hind leg joint of a jumping insect: Using katydids to inform bioinspired lubrication systems

Abstract This study investigates the structural properties of the hind leg femur-tibia joint in adult katydids (Orthoptera: Tettigoniidae), including its tribological and mechanical properties. It is of particular interest because the orthopteran (e.g., grasshoppers, crickets, and katydids) hind leg is highly specialized for jumping. We show that the katydid hind leg femur-tibia joint had unique surfaces and textures, with a friction coefficient (μ) at its coupling surface of 0.053 ± 0.001. Importantly, the sheared surfaces at this joint showed no sign of wear or damage, even though it had undergone thousands of external shearing cycles. We attribute its resiliency to a synergistic interaction between the hierarchical surface texture/pattern on the femoral surfaces, a nanograded internal nanostructure of articulating joints, and the presence of lubricating lipids on the surface at the joint interface. The micro/nanopatterned surface of the katydid hind leg femur-tibia joint enables a reduction in the total contact area, and this significantly reduces the adhesive forces between the coupling surfaces. In our katydids, the femur and tibia joint surfaces had a maximum effective elastic modulus (Eeff) value of 2.6 GPa and 3.9 GPa, respectively. Presumably, the decreased adhesion through the reduction of van der Waals forces prevented adhesive wear, while the contact between the softer textured surface and harder smooth surface avoided abrasive wear. The results from our bioinspired study offer valuable insights that can inform the development of innovative coatings and lubrication systems that are both energy efficient and durable. Statement of Significance Relative to body length, insects can outjump most animals. They also accelerate their bodies at a much faster rate. Orthopterans (e.g., grasshoppers, crickets, and katydids) have hind legs that are specialized for jumping. Over an individual’s lifetime, the hind leg joint endures repeated cycles of flexing and extending, including jumping, and its efficiency and durability easily surpass that of most mechanical devices. Although the efficient functioning of insect joints has long been recognized, the mechanism by which insect joints experience friction/adhesion/wear, and operate efficiently/reliably is still largely unknown. Our study on the structural, tribological, and mechanical properties of the orthopteran hind leg joints reveals the potential of katydid bioinspired research leading to more effective coatings and lubrication systems.
Fullerene quinazolinone conjugates targeting Mycobacterium tuberculosis: a combined molecular docking, QSAR, and ONIOM approach

Fullerene and its derivatives may bind to biological molecules, causing inhibitory effects. In this context, investigations of interactions of fullerene-based conjugates with proteins are of general interest. Particularly, fullerene and its derivatives demonstrate antibacterial properties; and one of the potential targets for drug design and health therapy is the inhibition of 6-oxopurine phosphoribosyltransferase in Mycobacterium tuberculosis (PDB code: 4RHY). In this article, the binding interactions between a series of quinazoline-4(3H)-ones and their fullerene derivatives with the target transferase were computationally investigated. Initially, we developed predictive quantitative structure-activity relationships (QSAR) models. Next, we introduced a simplified calculation schema that allows to evaluate relative binding affinities and to reveal specific mechanisms of action. For this purpose, the molecular docking approach was utilized to identify the native poses of the 18 transferase inhibitors. The binding pocket of the target protein was isolated and semi-empirical, and hybrid ONIOM scoring functions at different levels of theory were used to treat the ligands and the isolated binding pocket. The agreement within the calculated binding-free energies trends, as well as the agreement with the experimental data, suggests that the developed calculation schema can be used to estimate relative binding affinities towards 4RH. The combination of quantum-chemical models and QSAR models could be applied for future design of new selective inhibitors.
Expectations and experiences of nursing students in clinical courses: A descriptive study.

Abstract Background Students entering nursing programs have expectations for what they will encounter in the clinical setting. Objectives Nursing student excitement about beginning clinical, expectations for learning, anticipated time to prepare for each clinical day, and learning styles were examined. Design Descriptive study. Setting Baccalaureate nursing program in a public university in the Southeastern United States. Participants Students enrolled in their first clinical nursing courses. Methods Students responded to a survey at the beginning of their junior year (n = 96) and to a follow-up survey at the end of that academic year (n = 72). The initial survey asked what they were most excited about for junior year clinical experiences, what they expected to learn, the best way to learn skills and new content, and how long they expected to spend preparing for the clinical experience. The follow-up survey asked students what they were most excited about related to the upcoming senior year clinical experiences, what they thought were the important things they learned during their junior year that would help them practice as a registered nurse, and how long, on average, they spent preparing for clinical experiences. Results Initially, students were excited about experience/practice/observation and they expected to learn nursing skills and procedures. They expected to learn how to communicate effectively with patients and families. These same categories were dominant at follow-up. Learning styles for a new skill or new content varied among the students. Expectations for time in clinical preparation and time actually spent in this activity differed. Conclusions Students were excited and expected to learn predominantly nursing skills through hands-on experiences and active communication with patients. They have a variety of learning styles. Faculty must embrace expectations and learning styles of students and provide a variety of learning opportunities. Also, faculty should dispel unrealistic ideas about clinical experiences.
Comparison of hoop-net trapping and visual surveys to monitor abundance of the Rio Grande cooter (Pseudemys gorzugi)

Abundance estimates play an important part in the regulatory and conservation decision-making process. It is important to correct monitoring data for imperfect detection when using these data to track spatial and temporal variation in abundance, especially in the case of rare and elusive species. This paper presents the first attempt to estimate abundance of the Rio Grande cooter (Pseudemys gorzugi) while explicitly considering the detection process. Specifically, in 2016 we monitored this rare species at two sites along the Black River, New Mexico via traditional baited hoop-net traps and less invasive visual surveys to evaluate the efficacy of these two sampling designs. We fitted the Huggins closed-capture estimator to estimate capture probabilities using the trap data and distance sampling models to estimate detection probabilities using the visual survey data. We found that only the visual survey with the highest number of observed turtles resulted in similar abundance estimates to those estimated using the trap data. However, the estimates of abundance from the remaining visual survey data were highly variable and often underestimated abundance relative to the estimates from the trap data. We suspect this pattern is related to changes in the basking behavior of the species and, thus, the availability of turtles to be detected even though all visual surveys were conducted when environmental conditions were similar. Regardless, we found that riverine habitat conditions limited our ability to properly conduct visual surveys at one site. Collectively, this suggests visual surveys may not be an effective sample design for this species in this river system. When analyzing the trap data, we found capture probabilities to be highly variable across sites and between age classes and that recapture probabilities were much lower than initial capture probabilities, highlighting the importance of accounting for detectability when monitoring this species. Although baited hoop-net traps seem to be an effective sampling design, it is important to note that this method required a relatively high trap effort to reliably estimate abundance. This information will be useful when developing a larger-scale, long-term monitoring program for this species of concern.
What precipitation is extreme

A warmer atmosphere has more water vapor. Scientists have been trying to predict what this means for precipitation, but this is more complex and harder to model than temperature. One explanation has been that the intensity of extreme precipitation events will increase at a rate proportional to the increase in atmospheric moisture. But recent findings show that this explanation is too simplistic. There are many ways to define extreme precipitation, and the choice of definition affects how it responds to warming. Researchers must choose their definition of extreme precipitation with care and articulate it clearly, and users should consider how extreme precipitation is defined when interpreting analyses of its change with warming.
Identifying the Common Elements of a Commercial Website by Semantic Ontology

The main objective of this research was to examine the structure and content of a commercial website as well as identify the common elements between these websites by using the ontology concept. A semantic approach was employed, in order to describe the structure and classify the content in a commercial website. The objectives of each website were examined by professionals from advertising agencies who have more than one decade of experience in building a commercial website. The ontology of each website was developed based on website’s objectives. Common elements were found in the results of the experiment. However, there was a wide range of properties in a same type of element.
Bi-directional Y-Source DC Circuit Breaker Design and Analysis Under Different Conditions of Coupling

A Y -source impedance network is introduced to be a bidirectional circuit breaker for medium voltage direct current (MVDC) power systems. In this paper, designing, analysis, and evaluation of the bidirectional Y -source DC circuit breaker are presented under different conditions of coupling among the inductors. Breaker's transfer functions of impedance, current, and voltage are derived with a variable coupling coefficient. The frequency response of these functions is plotted as a magnitude and phase. The limitations of the fault conductance for two cases of the fault slope rate are derived as well. Upon the results, the breaker interrupts the source current during faults in case of coupling coefficient is higher than the null value. The turns ratio affects this value as explained in the paper. The simulation results confirm the effect of the coupling level on the breaker performance for two different values of the turns ratio.