cssi/SciSciGPT-SciSciNet huggingface dataset:
Concept Inventories: Predicting the Wrong Answer May Boost Performance

Several concept inventories have been developed to elicit students’ alternative conceptions in chemistry. It is suggested that heuristic reasoning may bias students’ answers in these types of assessments toward intuitively appealing choices. If this is the case, one could expect students to improve their performance by engaging in more analytical reasoning. Research has shown that analytical reasoning is activated when people experience metacognitive difficulty or conflict. This study presents the results of an intervention designed to trigger one of such experiences by asking students to make predictions about the wrong answers most commonly selected by unreflective students. Major findings show that this simple prompt has a significant positive impact on students’ answers, regardless of their academic performance in the course. The effects, however, are not uniform across different topics.
Disputas marítimas en el Caribe colombiano: la pesca de tortugas en el archipiélago de San Andrés y Providencia, 1910-1930❧

La pesca de tortugas tiene una larga historia en el Gran Caribe, especialmente en las aguas colombianas cerca del archipielago de San Andres y Providencia. De ahi que este articulo se enfoque en los esfuerzos colombianos por afirmar las fronteras nacionales y afianzar el control de las aguas territoriales, y en como estas medidas afectan con nuevas regulaciones a los pescadores de tortugas en el mar Caribe. Utilizando relatos de viajes, prensa jamaiquina, colombiana y estadounidense, correspondencia diplomatica, entrevistas y fuentes secundarias, este trabajo analiza las implicaciones nacionales y regionales de esta problematica. Eso permite concluir que los islenos, en compania de los funcionarios colombianos, intentaban defender su territorio insular y sus bordes maritimos de amenazas reales e imaginarias. Sus esfuerzos estaban dirigidos a restringir la extraccion de recursos marinos en las aguas territoriales, como parte de los intereses del Gobierno por reforzar la integridad del Estado-nacion colombi...
What Do Shakespearean Musicians Think? Complementary Rhetorical Devices in Romeo and Juliet and Byrd’s O that most rare breast

ABSTRACTIn Act 4, scene 5 of Romeo and Juliet, Shakespeare used the rhetorical figure of catachresis to capture the meta-theatrical thoughts of musicians as a way of expressing the “uncomfortable time” of Juliet’s apparent death on her wedding day. It is possible to trace Shakespeare’s source for the scene to O that most rare breast, William Byrd’s extensive dirge for Sir Philip Sidney. Not only does the song provide musical and funereal material, it also invites a writer’s response, as Byrd used a cross-disciplinary form of eristic imitation to outdo the rhetorical achievement of his text’s unnamed author.
Computationally Assessing the Bioactivation of Drugs by N-Dealkylation.

Cytochromes P450 (CYPs) oxidize alkylated amines commonly found in drugs and other biologically active molecules, cleaving them into an amine and an aldehyde. Metabolic studies usually neglect to report or investigate aldehydes, even though they can be toxic. It is assumed that they are efficiently detoxified into carboxylic acids and alcohols. Nevertheless, some aldehydes are reactive and escape detoxification pathways to cause adverse events by forming DNA and protein adducts. Herein, we modeled N-dealkylations that produce both amine and aldehyde metabolites and then predicted the reactivity of the aldehyde. This model used a deep learning approach previously developed by our group to predict other types of drug metabolism. In this study, we trained the model to predict N-dealkylation by human liver microsomes (HLM), finding that including isozyme-specific metabolism data alongside HLM data significantly improved results. The final HLM model accurately predicted the site of N-dealkylation within metabo...
nBn extended short-wavelength infrared focal plane array.

An extended short-wavelength nBn InAs/GaSb/AlSb type-II superlattice-based infrared focal plane array imager was demonstrated. A newly developed InAs0.10Sb0.90/GaSb superlattice design was used as the large-bandgap electron barrier in this photodetector. The large band gap electron-barrier design in this nBn photodetector architecture leads to the device having lower dark current densities. A new bi-layer etch-stop scheme using a combination of InAs0.91Sb0.09 bulk and AlAs0.1Sb0.9/GaSb superlattice layers was introduced to allow complete substrate removal and a shorter wavelength cut-on. Test pixels exhibit 100% cutoff wavelengths of ∼2.30 and ∼2.48 μm at 150 and 300 K, respectively. The devices achieve saturated quantum efficiency values of 59.7% and 63.8% at 150 and 300 K, respectively, under backside illumination and without any antireflection coating. At 150 K, photodetectors exhibit dark current density of 8.75×10−8 A/cm2 under −400 mV applied bias, providing specific detectivity of 2.82×1012 cm·Hz1/2/W at 1.78 μm. At 300 K, the dark current density reaches 4.75×10−2 A/cm2 under −200 mV bias, providing a specific detectivity of 8.55×109 cm·Hz1/2/W 1.78 μm.
A Collaborative Programming and Outreach Model for International Student Support Offices

Increasing international student enrollment has been a key priority for many institutions of higher education in the United States. Such recruitment efforts, however, are often carried out without much consideration for providing sufficient support services to these students once they arrive to campus. This article proposes a model for structuring an international student support office to be successful at serving the academic, social and cultural needs of international students through a collaborative programming and outreach model with student affairs and other support service units on campus.
The Role of Torsional Dynamics on Hole and Exciton Stabilization in π-Stacked Assemblies: Design of Rigid Torsionomers of a Cofacial Bifluorene.

Exciton and charge delocalization across π-stacked assemblies is of importance in biological systems and functional polymeric materials. To examine the requirements for exciton and hole stabilization, cofacial bifluorene (F2) torsionomers were designed, synthesized, and characterized: unhindered (model) Me F2, sterically hindered tBu F2, and cyclophane-like C F2, where fluorenes are locked in a perfect sandwich orientation via two methylene linkers. This set of bichromophores with varied torsional rigidity and orbital overlap shows that exciton stabilization requires a perfect sandwich-like arrangement, as seen by strong excimeric-like emission only in C F2 and Me F2. In contrast, hole delocalization is less geometrically restrictive and occurs even in sterically hindered tBu F2, as judged by 160 mV hole stabilization and a near-IR band in the spectrum of its cation radical. These findings underscore the diverse requirements for charge and energy delocalization across π-stacked assemblies.
Memory consolidation: Systems

Memories of facts and events can last a lifetime, but the neural substrates of these memories are not static. Neuronal modification and more effective storage may result from hippocampal–cortical interactions during walking as well as during sleep. Hippocampal networks can function to conjointly activate a spatially distributed set of storage locations in the cerebral cortex. Whereas memory retrieval initially depends on both hippocampal and cortical networks, following consolidation neocortical networks can be sufficient for memory retrieval, though sometimes these memories lack contextual detail. Important questions remain about how declarative memories are represented, how consolidation operates on these representations, and how defective consolidation can cause retrograde amnesia.
The Geometry of Nanoscale Carbon

Carbon’s rich variety of two-dimensional structures arises not only from kinetics, but also because three-dimensional sp 3 -bonded diamond-like structures are actually slightly less stable than graphite at zero pressure. The development of large, complex two-dimensional structures is not arrested by another transition in dimensionality, as happened for one-dimensional structures. In contrast to carbon, clusters of nearly all other elements are essentially always three-dimensional, with edge effects imposing at most a local surface reconstruction.
Blood-Optic Nerve Barrier

The blood-optic nerve barrier is an important subject in any consideration of optic nerve and optic nerve head (ONH) vascular disorders. The capillaries in the ONH and the rest of the optic nerve, as in the retina [1–5] and in the central nervous system [6–10] have tight cell junctions between adjacent endothelial cells, without fenestration [11–13]. These tight junctions are responsible for the blood-optic nerve barrier, which has been shown by intravenous injection of tracer substances, such as horseradish peroxidase [14–16] and diaminoacridines [17].
Multiple Chemical Sensitivity: State of the Art Symposium: The Role of Chemical Allergens

Abstract Multiple chemical sensitivity (MCS) has been defined as “an acquired disorder of recurrent symptoms, referable to multiple organ systems, occurring in response to chemically unrelated compounds at doses far below those established in the general population to cause harmful effects” [Cullen,State Art Rev. Occup. Med.2, 655 (1987)]. The pathophysiologic basis for the MCS syndrome has not been clearly defined. However, allergic reactions to specific chemicals encountered in the environment are much better understood.
Addressing Local Class Imbalance in Balanced Datasets with Dynamic Impurity Decision Trees

Decision trees are among the most popular machine learning algorithms, due to their simplicity, versatility, and interpretability. Their underlying principle revolves around the recursive partitioning of the feature space into disjoint subsets, each of which should ideally contain only a single class. This is achieved by selecting features and conditions that allow for the most effective split of the tree structure. Traditionally, impurity metrics are used to measure the effectiveness of a split, as ideally in a given subset only instances from a single class should be present. In this paper, we discuss the underlying shortcoming of such an assumption and introduce the notion of local class imbalance. We show that traditional splitting criteria induce the emergence of increasing class imbalances as the tree structure grows. Therefore, even when dealing with initially balanced datasets, class imbalance will become a problem during decision tree induction. At the same time, we show that existing skew-insensitive split criteria return inferior performance when data is roughly balanced. To address this, we propose a simple, yet effective hybrid decision tree architecture that is capable of dynamically switching between standard and skew-insensitive splitting criterion during decision tree induction. Our experimental study depicts that local class imbalance is embedded in most standard classification problems and that the proposed hybrid approach is capable of alleviating its influence.
Why we care about 1968

I would first like to thank the organizers of this symposium for posing as the frame for our dialogue, the question: “Why do we still care about 1968?” and not, as they might have, “Why does 1968 s...
Estimation of the Angular Positioning Inaccuracy in Avionics Helmet-Mounted Cueing Systems with Magnetic Method

The paper presents methods for estimating the inaccuracy of determining the angular position of the pilot’s helmet dedicated to the NSC-1 Orion helmet-mounted cueing system with a magnetic method, intended for the W-3PL Gluszec multi-purpose helicopter with integrated avionics system ZSA. A flat coil with two separated rings, which generates a magnetic field with a curved profile from the axis of symmetry, developed in the Polish Air Force Institute of Technology (AFIT), was presented. The magnetic field curvature causing errors of determining the angular position of the pilot’s helmet in relation to the aircraft cabin reference frame was described with the use of relationships formulated for the flat coil with two separated rings (inner and outer). The inaccuracies determined on the basis of computer simulations of the developed mathematical relationships were compared with experimental data obtained from the magnetic field measurements using the integrated ADIS 16405 triaxial sensor (with a measurement resolution of 0.5 mgauss/LSB). In order to improve the accuracy of determining the angular position, an original algorithm for specifying linear deviations of the pilot’s helmet from its neutral position, determined during the adjustment process of the helmet (located on the axis of symmetry of the flat coil) was used. It allowed to determine the current curvature of the generated magnetic field and to make corrections.
One-Step-Ahead Adaptive Control Scheme for Active Rectifiers in Wild Frequency Applications

In this paper, an adaptive control scheme for active rectifiers in wild frequency applications is presented. The proposed controller addresses the performance degradation when the parameters of the model deviate from the actual system parameters in a variable frequency power system, e.g. More Electric Aircraft. In particular, the proposed control scheme dynamically tracks the parameters of the input filter of the converter in order to minimize the prediction error in the one-step-ahead algorithm. Experimental results on a SiC-based active rectifier are provided to assess the effects of model parameter mismatch under variable frequency, and verify the performance of the proposed control scheme using input frequency acceleration and deceleration ramps at a rate of 250Hz/s. The results show that the proposed control scheme has a rapid dynamic response as a result of the one-step-ahead controller and the adaptation laws implemented in the model reference, which translates into fast and accurate system parameter tracking, while maintaining the dc voltage well regulated and the rectifier operating at unity power factor.
A role for neutrophil gelatinase-associated lipocalin in regulating tumor angiogenesis

438 Neutrophil gelatinase-associated lipocalin (NGAL, lipocalin 2) is a member of the lipocalin family. Lipocalins are small extracellular proteins that share the highly conserved structure of an 8-stranded anti-parallel barrel and have been shown to transport and present ligands, to bind to cell-surface receptors, and to form macromolecular complexes. Increased NGAL expression has been reported in a variety of human cancers including breast, colon, ovarian, pancreatic, liver and lung cancer, however, the function of NGAL in cancer development and progression remains unknown. In this study, we asked whether NGAL might play a role in tumor angiogenesis. Stable clones expressing NGAL were established from the human breast cancer cell line MCF-7. We found that vascular endothelial growth factor (VEGF) was significantly induced in NGAL-expressing cells at both the mRNA and protein levels compared to parental MCF-7 cells. We next examined the expression of hypoxia-inducible factor-1 α (HIF-1α), one of the most important regulators of VEGF transcription, and found that HIF-1α protein levels were also increased in NGAL-expressing cells. Interestingly, the levels of HIF-1α transcripts remained the same between NGAL-expressing cells and parental MCF-7 cells, suggesting that HIF-1α was regulated by NGAL only at the translational level. Next, NGAL was silenced using specific siRNA constructs in another breast cancer cell line, MDA-MB-231, which expresses high levels of NGAL. Both VEGF and HIF-1α levels were reduced in MDA-MB-231 cells with NGAL silencing thereby supporting our findings with MCF-7 cells that NGAL may regulate HIF-1α and VEGF. Finally, we asked whether NGAL affected tumor angiogenesis in vivo. NGAL-expressing cells and parental MCF-7 cells were grown subcutaneously in female nude mice and increased tumor angiogenesis was observed in NGAL-expressing tumors compared to tumors formed with parental MCF-7 cells. In conclusion, these data suggest that NGAL may promote breast cancer angiogenesis, at least in part, by inducing VEGF expression. (This work is supported by NIH R01 CA118764 and the JoAnn Webb Fund for Angiogenesis Research.)
Mitigating EM Edge Artifacts Using Null-Space Smoothing

The objective of this research is to investigate the potential of total variation (TV) nullspace smoothing to mitigate the edge artifacts produced in expectation maximization (EM) reconstruction. Its success in reducing noise and preserving edges in image restoration, suggests that TV norm minimization could be explored in the reconstruction of positron emission tomography (PET) images. For example, the following criteria could be used for reconstruction: Find the image that has the minimum TV norm such that the measurements produced by the image are sufficiently close to the actual measurements. It is argued here, however, that this criterion may cause distortion of edges because of the Poisson nature of PET measurements. Moreover, the above criterion does not exploit the Poisson model of the data as the EM algorithm does. As a potentially better alternative, TV nullspace smoothing of EM reconstructions is proposed here. Rather than minimizing the whole EM reconstructed image with respect to the TV norm, in nullspace smoothing, only a portion of the reconstructed image is minimized; namely, the nullspace component of the reconstructed image. This may be advantageous because PET data contains no information about the nullspace component of the object being scanned. A second potential advantage stems from the fact that EM algorithm attempts to find an image that maximizes the likelihood function associated with a Poisson model of the data. The nullspace smoothed image is as optimal, in the maximum likelihood sense, as the original unsmoothed image. Methodology. To perform this investigation, noise-less projections of a mathematical phantom were simulated. Results. It was seen that the edge artifacts of the TV nullspace smoothed image were uniformly better than those in the original unsmoothed EM reconstruction. Conclusion. Although the results presented here are encouraging, more work needs to be done in the future to demonstrate the usefulness of nullspace smoothing with real data.
Physician Brain Drain: Does Health Expenditure Matter?

Although previous research on migration has documented skilled migrants’cross-border activities very few empirical studies have examined physician migration. Inrecent years, the migration of physicians from developing to developed countries hasreceived a great deal of attention and raised much concern. In this study, a gravity modeland the Poisson pseudo-maximum-likelihood (PPML) estimator was used to examine theimpact of various health expenditure variables on physician migration to the UnitedStates. The empirical results show that inadequate total expenditure on health, as well asinadequate government and private expenditure on health, encourage physicians fromdeveloping countries to migrate to the United States. (F2; F22)
Geswein hole: A fanciful Wikipedian medical eponym for preauricular sinus

In the English version of the online encyclopaedia, Wikipedia, we find the term "Geswein hole" mentioned as another name for preauricular sinus. On the Wikipedia page, the following note "Geswein, a familial name of German descent" is used as a reference. The aim of this study is to delineate the origin of this eponym. After an introductory compilation of the modern 20th and 21st centuries literature, the research was conducted at three levels: the compilation of all cited references on the Wikipedia page; the systematic study of the first description of this entity from 1864 to 1878, also sometimes termed fistula auris congenita; and the study of German references dealing with this subject from 1879 to 1901. No track of this eponym was found. Geswein hole must be considered a modern fanciful Wikipedian medical eponym! This clearly demonstrates the dangers of using anonymous internet references, notably Wikipedia.
Limit theorems for a discrete-time Hawkes process

The Hawkes process is a self-exciting sample point process. It has wide applications in finance, social networks, criminology, seismology, and many other fields. With the development of storage technology, data-driven models are attracting more attention. Furthermore, in reality, events are often recorded in a discrete-time scheme. However, Hawkes process is defined for continuous time setting. In this paper, we propose a discrete-time marked Hawkes process and study the limit theorems for the model.
Cost, Hassle, and On-Body Experience: Barriers to Diabetes Device Use in Adolescents and Potential Intervention Targets.

Background: Adolescents with diabetes have the highest A1cs of all age groups. Diabetes devices (insulin pumps and continuous glucose monitors [CGM]) can improve glycemic outcomes, and although the...
Strength and Stiffness of 8-Inch Deep Mixed Hardwood Composite Timber Mats

There is a current and pressing need to develop engineering standards for timber- and other wood-based mats. In 2018 a group of mat producers and users began discussing a potential grading specification standard specific to mats. There are large gaps in the literature regarding the performance of the available raw materials as well as bolt-laminated mat systems. This work represents a novel attempt to begin to assess the mechanical properties of timber mats. Eight-inch deep mixed hardwood timbers were graded according to an experimental specification standard. Then, they were drilled and bolt laminated into 28 three-timber composite mats that were 24 inches (60.96 cm) in width. The bending stiffness (modulus of elasticity [MOE]) and strength (modulus of rupture [MOR]) performance were evaluated with a static bending test. The 5th percentile nonparametric tolerance limit (5% NTL) and design value for fiber stress in bending (Fb) were calculated. The nonparametric design value compared favorably with that of graded timbers, as described in the 2018 National Design Specification (NDS) for wood.
Children’s judgements of the obligation to help: The role of relationships

Children at ages 7 (N = 24, M age = 6.96, SD age =.20), 9 (N = 29, M age = 8.76, SD age =.44), and 11 (N = 25, M age = 10.76, SD age =.66), and adults (N = 30) made judgements about the obligation ...
Effect of frother strength on gas dispersion in a cavitation sparger measured by electrical resistance tomography

Abstract Axial dispersion in column flotation is critical for optimizing particle-bubble interaction and maximizing recovery. The effect of different flotation frothers on axial gas dispersion rates in a column flotation cell were measured using electrical resistance tomography (ERT). Gas holdup can be measured using ERT and utilized in the determination of axial gas dispersion rate in the column. The ERT is constructed with two sensor planes making it possible to simultaneously capture gas holdup values at and immediately above the cavitation sparger. Three frothers of varying strengths were used to investigate axial dispersion rates. Experimental conditions were modified by altering the superficial gas rate, frother concentration, and sparger pump speed. Utilizing a two-phase (gas–liquid) system, the effects of varying experimental conditions were captured and are represented using concentration tomograms. There is a strong positive correlation between axial dispersion rate, frother strength, and machine operating parameters.
Evaluation of Polyhedral Oligomeric Silsesquioxane Porphyrin Derivatives on Photodynamic Therapy

Polyhedral oligomeric silsesquioxane (POSS) is a promising scaffold to be used as delivery system. POSS can modify the properties of photosensitizers to enhance their efficacy toward photodynamic therapy (PDT). In this work, we designed, synthesized and characterized five different POSS porphyrin (POSSPs 1-5) derivatives containing hydrophobic (1-3) and hydrophilic (4 and 5) functional groups. In general, all the POSSPs showed a better singlet oxygen quantum yield than the parent porphyrins due to the steric hindrance from the POSS unique structure. POSSPs 1 and 3 containing isobutyl groups showed better PDT performance in cancer cells at lower concentrations than POSSPs 4 and 5. However; at higher concentrations, the POSSP4 containing hydrophilic groups has an enhanced PDT efficiency as compared with the parent porphyrin. We envision that the chemical tunability of POSSs can be used as a promising option to improve the delivery and performance of photosensitizers.
Friedrich Schiller and the Aestheticization of Ethics

This chapter discusses Friedrich Schiller’s critical response to the conception of moral agency advanced by Kant, who was Schiller’s main source of inspiration and criticism in both aesthetics and ethics. Criticizing Kant for his disregard to inclination, Schiller argues that a complete conception of moral life can be sustained only if we recognize the moral value of sensuous and understand moral agency as a harmonious unity of both duty and inclination. The chapter shows that at the very core of Schiller’s ethical theory lies the notion of aesthetics that becomes a specific experience of freedom and thus an essential accompaniment of morality itself. The chapter also reveals how Schiller’s aesthetics assigns a distinctive place for the development of general moral sentiments and permits the cultivation of man toward the truly moral individual.
Durability of Macroplastique volume and configuration in women with stress urinary incontinence secondary to intrinsic sphincter deficiency: A retrospective review

Objectives To evaluate the durability of Macroplastique® (MPQ) volume and configuration in women with stress urinary incontinence (SUI) secondary to intrinsic sphincter deficiency (ISD) using serial three-dimensional ultrasound (3DUS) measurements. Methods Following Institutional Review Board approval, charts of women with SUI and ISD (defined based on leak point pressure; lateral imaging of urethral support without hypermobility) who underwent MPQ were reviewed from a prospectively maintained database. All had at least two serial transperineal 3DUS measurements with no MPQ or other bulking agent injection between measurements. 3DUS was performed using the Philips IU22 ultrasound system with endovaginal 3D 9-3V end-fire probe typically at 6-8 weeks post-injection and yearly thereafter. The same imaging team blinded to clinical outcomes evaluated volume and configuration (circumferential/symmetric or asymmetric) at each 3DUS. Results Between 2011 and 2019, 62 of 174 women met study criteria. Those with prior other bulking agent injection or having ≤1 3DUS follow-up were excluded. Seventy-one percent of patients had one injection, while the remainder had two or more (29%). Median time between first and second 3DUS was 12 months. The mean change in MPQ volume between the first and last 3DUS measurement was -0.2 cc (95% CI: -0.5 to 0.004; P = .054). A median of 5.0 cc were injected in each patient. Forty-seven women had symmetric MPQ at first 3DUS, of whom only five (11%) had a follow-up 3DUS showing asymmetric MPQ distribution. Conclusions At mid-term follow-up, repeat transperineal 3DUS after MPQ injection revealed minimal change in volume and configuration in the urethral wall.
Decreased Mortality Rate Among COVID-19 Patients Prescribed Statins: Data From Electronic Health Records in the US

The severe respiratory illness due to SARS-CoV-2, the virus responsible for coronavirus disease 2019 (COVID-19), is triggered by an intense pro-inflammatory host response. Statins, prescribed primarily for lipid reduction, are known to have anti-inflammatory and immunomodulatory properties and have been associated with a reduced mortality rate among COVID-19 patients taking statins as reported in two recent retrospective studies. However, a meta-analysis that included nine studies showed that statin use did not improve in-hospital outcomes of those with COVID-19. In addition, concerns regarding the use of statins and an increase in COVID-19 infections have been raised, as statins may increase the expression of angiotensin-converting enzyme 2 (ACE2), the primary receptor for the SARS-CoV-2 virus. Our goal was to investigate the effect of statins in COVID-19 patients in a large, diverse patient population across the United States containing nearly 120,000 patients diagnosed with COVID-19. We used propensity score matching of demographics, comorbidities, and medication indication to compare statin-treated patients (N = 2,297) with matched controls (N = 4,594). We observed a small, but statistically significant, decrease in mortality among patients prescribed statins (16.1%) when compared with matched COVID-19-positive controls (18.0 to 20.6%). These results support previous evidence that statins do not increase COVID-19-related mortality and may, in fact, have a mitigating effect on severity of the disease reflected in a slight reduction in mortality. Mixed findings on effects of statins in COVID-19 patients reported in the literature should prompt prospective randomized controlled trials in order to define better who might be advantaged with respect to clinical outcomes.
Muscle Dysmorphia and Disordered Eating Behavior

Muscle dysmorphia (MD) is a relatively recently identified psychiatric phenotype which encapsulates the pathological pursuit of muscularity and a pervasive belief that one is of insufficient muscularity. While rates are hard to estimate due to sparse data, MD has been reported to occur among both men and women and is associated with broad impairments to quality of life and functioning, and comorbid with eating concerns obsessive-compulsive symptomatology, and has been linked to elevated suicidality. With this increasing awareness of the dangers associated with MD, alongside a steadily increasing prevalence, focused efforts must now go toward the development of evidence-based treatment approaches.
The Oral Bacterial Communities of Children with Well-Controlled HIV Infection and without HIV Infection.

The oral microbial community (microbiota) plays a critical role in human health and disease. Alterations in the oral microbiota may be associated with disorders such as gingivitis, periodontitis, childhood caries, alveolar osteitis, oral candidiasis and endodontic infections. In the immunosuppressed population, the spectrum of potential oral disease is even broader, encompassing candidiasis, necrotizing gingivitis, parotid gland enlargement, Kaposi’s sarcoma, oral warts and other diseases. Here, we used 454 pyrosequencing of bacterial 16S rRNA genes to examine the oral microbiome of saliva, mucosal and tooth samples from HIV-positive and negative children. Patient demographics and clinical characteristics were collected from a cross-section of patients undergoing routine dental care. Multiple specimens from different sampling sites in the mouth were collected for each patient. The goal of the study was to observe the potential diversity of the oral microbiota among individual patients, sample locations, HIV status and various dental characteristics. We found that there were significant differences in the microbiome among the enrolled patients, and between sampling locations. The analysis was complicated by uneven enrollment in the patient cohorts, with only five HIV-negative patients enrolled in the study and by the rapid improvement in the health of HIV-infected children between the time the study was conceived and completed. The generally good oral health of the HIV-negative patients limited the number of dental plaque samples that could be collected. We did not identify significant differences between well-controlled HIV-positive patients and HIV-negative controls, suggesting that well-controlled HIV-positive patients essentially harbor similar oral flora compared to patients without HIV. Nor were significant differences in the oral microbiota identified between different teeth or with different dental characteristics. Additional studies are needed to better characterize the oral microbiome in children and those with poorly-controlled HIV infections.
Synchronous universal droplet logic and control

A computer based on droplets moving in microfluidic channels requires synchronous manipulation of the droplets. Such synchronous logic is now shown for a system of ferrofluid droplets, with a rotating magnetic field providing the computer clock rate.
Downstream geomorphic variation and local bedrock influence of a steep transitional river: Blue Ridge to Piedmont, South Carolina

Spatial patterns in geomorphic variations are examined in a river transition from the Southern Blue Ridge to the Piedmont physiographic regions. Downstream hydraulic geometry (DHG), fining of bed material, and changes in reach-scale channel-bed morphology (bedforms) were sampled and analyzed. DHG power functions were well developed (r2 > 0.75 for channel area, width, and depth). Bed material showed a general downstream exponential decrease in caliber (from 940 mm to sand). However, variations within the general downstream trends reflect local variations and a rapid transition in hydraulic variables and bedforms at a key zone with substantial tributary inputs, decreases in slope, and a punctuated longitudinal profile. Structurally controlled bedrock knickpoints are associated with anomalous spatial patterns of bedforms and can be distinguished through relationships between dimensionless sediment transport capacity and sediment supply using a sediment regime diagram that is independent of drainage area. Plo...
Generation and characterization of topoisomerase IIα mutants (549.5)

Topoisomerases are nuclear enzymes that regulate DNA topology and remove knots and tangles in the genetic material. While the anticancer agent etoposide is highly effective at inducing topoisomerase II-mediated DNA damage, etoposide is also metabolized into a catechol and a highly active quinone. To further study the mechanism of the metabolites, we are developing human topoisomerase IIα mutants with altered sensitivity to etoposide. Based upon published studies, we identified amino acid positions that may influence enzyme response to etoposide. Using a PCR-based mutagenesis process, we mutated Gly462 to Ala, Asp463 to Glu, Arg487 to Lys, Ala429 deletion, Gly534 to Arg, Gly449 to Asp, and Pro716 to Leu. We used biochemical assays to analyze the DNA cleavage and relaxation activities of the mutant enzymes in the presence and absence of etoposide. Our results demonstrate that five mutants are functional (R487K, D463E, ΔA429, P716L, and G534R), one mutant has activity too low to quantify (G462A), and one is ...
Digital frequency-lock loop using high-resolution TAC and advanced control algorithm for trapped-ion frequency standards

A local oscillator for the Linear Ion Trap Standard (LITS) has been designed and tested It uses a Time-to-Analogue (TAC) converter to achieve the required resolution and low noise. The TAC has an instantaneous resolution of 23 bits and an accumulative resolution of approximately 34 bits. The noise analysis, circuit details and block diagram are given, as well as the performance of the loop.
Measurements of 18O18O and 17O18O in the atmosphere and the role of isotope‐exchange reactions

[1] Of the six stable isotopic variants of O2, only three are measured routinely. Observations of natural variations in 16O18O/16O16O and 16O17O/16O16O ratios have led to insights in atmospheric, oceanographic, and paleoclimate research. Complementary measurements of the exceedingly rare 18O18O and 17O18O isotopic variants might therefore broaden our understanding of oxygen cycling. Here we describe a method to measure natural variations in these multiply substituted isotopologues of O2. Its accuracy is demonstrated by measuring isotopic effects for Knudsen diffusion and O2 electrolysis in the laboratory that are consistent with theoretical predictions. We then report the first measurements of 18O18O and 17O18O proportions relative to the stochastic distribution of isotopes (i.e., Δ36 and Δ35 values, respectively) in tropospheric air. Measured enrichments in 18O18O and 17O18O yield Δ36 = 2.05 ± 0.24‰ and Δ35 = 1.4 ± 0.5‰ (2σ). Based on the results of our electrolysis experiment, we suggest that autocatalytic O(3P) + O2 isotope exchange reactions play an important role in regulating the distribution of 18O18O and 17O18O in air. We constructed a box model of the atmosphere and biosphere that includes the effects of these isotope exchange reactions, and we find that the biosphere exerts only a minor influence on atmospheric Δ36 and Δ35 values. O(3P) + O2 isotope exchange in the stratosphere and troposphere is therefore expected to govern atmospheric Δ36 and Δ35 values on decadal timescales. These results suggest that the ‘clumped’ isotopic composition of atmospheric O2in ice core records is sensitive to past variations in atmospheric dynamics and free-radical chemistry.
Cloud-induced uncertainties in AIRS and ECMWF temperature and specific humidity

The uncertainties of the Atmospheric Infrared Sounder (AIRS) Level 2 version 6 specific humidity (q) and temperature (T) retrievals are quantified as functions of cloud types by comparison against Integrated Global Radiosonde Archive radiosonde measurements. The cloud types contained in an AIRS/Advanced Microwave Sounding Unit footprint are identified by collocated Moderate Resolution Imaging Spectroradiometer retrieved cloud optical depth (COD) and cloud top pressure. We also report results of similar validation of q and T from European Centre for Medium-Range Weather Forecasts (ECMWF) forecasts (EC) and retrievals from the AIRS Neural Network (NNW), which are used as the initial state for AIRS V6 physical retrievals. Differences caused by the variation in the measurement locations and times are estimated using EC, and all the comparisons of data sets against radiosonde measurements are corrected by these estimated differences. We report in detail the validation results for AIRS GOOD quality control, which is used for the AIRS Level 3 climate products. AIRS GOOD quality q reduces the dry biases inherited from the NNW in the middle troposphere under thin clouds but enhances dry biases in thick clouds throughout the troposphere (reaching −30% at 850 hPa near deep convective clouds), likely because the information contained in AIRS retrievals is obtained in cloud-cleared areas or above clouds within the field of regard. EC has small moist biases (~5–10%), which are within the uncertainty of radiosonde measurements, in thin and high clouds. Temperature biases of all data are within ±1 K at altitudes above the 700 hPa level but increase with decreasing altitude. Cloud-cleared retrievals lead to large AIRS cold biases (reaching about −2 K) in the lower troposphere for large COD, enhancing the cold biases inherited from the NNW. Consequently, AIRS GOOD quality T root-mean-squared errors (RMSEs) are slightly smaller than the NNW errors in thin clouds (1.5–2.5 K) but slightly larger than the NNW errors for thick COD (reaching 3.5 K near the surface). The AIRS BEST quality control retains retrievals with uncertainties closer to those of the NNW. The AIRS error estimates reported in the L2 product tend to underestimate the precision (RMSE) implied by comparisons to the radiosonde measurements and do not reflect the observed cloud dependency of uncertainties.
Need for a Noninvasive Technique to Measure Cochlear Responses

The cochlear microphonic response measured at the round window is an important tool for evaluating the condition of the outer hair cells at high frequencies. The cochlear microphonic response was utilized to evaluate the condition of the cochlea while systematically experimenting with different methods of opening the bulla cavity
Factors affecting radiolytic effects in food

Abstract On basis of radiation chemical considerations supported by model system studies, several general predictions can be made regarding the influence of specific parameters on the chemical effects in irradiated foods. Among the parameters considered are: food composition, physical state of components, irradiation temperature, dose-rate, and total dose. Composition determines the type and extent of reactions initiated by both direct and indirect radiolytic interaction. The multiphasic character of foods influences cross reactions between components. State of hydration introduces both physical and chemical aspects into these considerations. Irradiating systems in which the water is frozen changes substantially the chemical effects because the diffusion of reactive entities is impeded. Temperature, especially is frozen systems, has a specific effect on the type and extent of reactions that could occur. Dose and dose-rate, insofar as they affect the pathways for reaction of intermediate species with the original or new components, also determine the type and amount of final radiolysis products. Illustrations of many of these features of the chemistry have been drawn from experiments on model systems of proteins, frozen aqueous solutions, and compounds derived from lipids, as well as from irradiated meats and poultry. These considerations and related experimental results explain the validity of using chemical data to obtain clearances and to extend clearances from approved foods to other foods or to other irradiation conditions.
The Role of Cognitive and Cultural Sophistication on Diversity Outcomes: Differences Across Fields of Study

Social scientists generally consider college education important in increasing tolerance toward other social groups, and studies show a positive relation between education and tolerance. Despite this positive relation, previous research generally does not examine the influence of fields of study on diversity outcomes. Moreover, prior research has used crude measures to test the influence of cognitive and cultural sophistication, the proposed mechanism through which education increases tolerance. Using longitudinal data of college students, this research addressed whether the “liberalizing” effects of college education on diversity outcomes are due to the increase in cognitive and cultural sophistication, as proponents claim or whether these liberalizing effects of college education on diversity outcomes differ by fields of study. Partial support was found that cognitive and cultural sophistication increase diversity outcomes. Students’ need for cognition and peer discussions about diversity increases diversity outcomes. Little evidence was found that the influence of cognitive and cultural sophistication on diversity outcomes differs by fields of study. Although the influence of cognitive and cultural sophistication on diversity outcomes is similar across fields of study, differences in the degree of exposure to cognitive and cultural sophistication account for a large share of the gap in diversity outcomes by fields of study.
Estimating the cost of children and some results from urban United States

The testing of economic theories of fertility has been hampered by the absence of suitable data on the direct (versus opportunity) costs of children. This study hopes to help remedy this deficiency, first, by proposing a new method of estimating the magnitude of money expenditures parents make on their children. This method is then applied to the urban sample of the 1960–1961 U.S. Consumer Expenditure Survey to estimate the total money expenditure costs of children to age eighteen. The distribution of these costs by income level, by birth order, by age of the child, and by components of cost (food, housing, clothing, and so on) is considered. The impact of the number and age of children on family living standards is also explored.
Pairing correlations in nuclei: old knowledge and new ideas

Abstract We present a limited overview of recently suggested ideas for the description of pairing correlations in nuclei. Exact solution for the pairing problem and based on that new theoretical approximations, phase transition to the paired state, “pair-vibrational” excitations, role of incoherent residual interactions, pairing in the continuum, and other related subjects are discussed.
Active wideband 350GHz imaging system for concealed-weapon detection

A prototype active wideband 350 GHz imaging system has been developed to address the urgent need for standoff concealed-weapon detection. This system is based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed conical scanner. This system is able to quickly scan personnel for concealed weapons. Additionally, due to the wideband operation, this system provides accurate ranging information, and the images obtained are fully three-dimensional. Waves in the microwave, millimeter-wave, and terahertz (3 GHz to 1 THz) frequency bands are able to penetrate many optical obscurants, and can be used to form the basis of high-resolution imaging systems. Waves in the sub-millimeter-wave band (300 GHz to 1 THz) are particularly interesting for standoff concealed-weapon detection at ranges of 5 - 20+ meters, due to their unique combination of high resolution and clothing penetration. The Pacific Northwest National Laboratory (PNNL) has previously developed portal screening systems that operate at the lower end of the millimeter-wave frequency range around 30 GHz. These systems are well suited for screening within portals; however, increasing the range of these systems would dramatically reduce the resolution due to diffraction at their relatively long wavelength. In this paper, the standoff 350 GHz imaging system is described in detail and numerous imaging results are presented.
The question of differential hydrogen bonding in the mechanism of catalysis by serine proteases

Abstract Two mechanisms recently proposed to account for the action of serine in proteases differ on the matter of hydrogen bonding between enzyme and substrate in the Michaelis complex and acyl enzyme. One mechanism involves the removal of hydrogen bonds as a means of raising the free energy of the Michaelis complex toward that of the transition state and thereby effecting catalysis. This report shows that the kinetic parameters k 2 K s and k3 for the α-chymotrypsin-catalyzed hydrolysis of a series of halogen-substituted phenyl acetates respond to electron with-drawal and concomitant changes in hydrogen bond energy in a nearly identical fashion. Reference to thermodynamic studies of hydrogen bonding in free solution shows that these data are not consistent with hydrogen bond removal in the Michaelis complex and acyl enzyme but do support the alternative mechanism, in which hydrogen bonding of substrate is maintained along the entire reaction coordinate.
Catalytic wet air oxidation of phenol in concurrent downflow and upflow packed-bed reactors over pillared clay catalyst

Abstract An experimental study is presented for comparing the behavior of a packed bed reactor in the catalytic liquid-phase oxidation of aqueous phenol with two modes of operation, downflow and upflow. The operating parameters investigated included temperature, reactor pressure, gas flowrate, liquid hourly space velocity and feed concentration. Because of the completely wetted catalyst, the upflow reactor generally performs better for high pressures and low feed concentrations when the liquid reactant limitation controls the rate. The interaction between the reactor hydrodynamics, mass transfer, and reaction kinetics is discussed. For both operation modes, complete phenol removal and significant total organic carbon (TOC) reduction can be achieved at rather mild conditions of temperature (150–170 °C) and total pressure (1.5–3.2 MPa). The results show that the phenol and TOC conversion are considerably affected by the temperature, while the air pressure only has minor influence. Total elimination of TOC is difficult since acetic acid, as the main intermediate, is resistant to catalytic wet oxidation. All tests were conducted over extrudates of Fe–Al pillared clay catalyst, which is stable and maintains its activity during the long-term experimental process. No significant catalyst deactivation due to metal ion leaching and polymer deposition was detected.