cssi/SciSciGPT-SciSciNet huggingface dataset:
New developments in observer performance methodology in medical imaging.

A common task in medical imaging is assessing whether a new imaging system, or a variant of an existing one, is an improvement over an existing imaging technology. Imaging systems are generally quite complex, consisting of several components—for example, image acquisition hardware, image processing and display hardware and software, and image interpretation by radiologists- each of which can affect performance. Although it may appear odd to include the radiologist as a "component" of the imaging chain, because the radiologist's decision determines subsequent patient care, the effect of the human interpretation has to be included. Physical measurements such as modulation transfer function, signal-to-noise ratio, are useful for characterizing the nonhuman parts of the imaging chain under idealized and often unrealistic conditions, such as uniform background phantoms and target objects with sharp edges. Measuring the performance of the entire imaging chain, including the radiologist, and using real clinical images requires different methods that fall under the rubric of observer performance methods or "ROC" analysis, that involve collecting rating data on images. The purpose of this work is to review recent developments in this field, particularly with respect to the free-response method, where location information is also collected.
Finite-amplitude baroclinic instability with periodic forcing

Abstract A low-order model is used to study the behavior of large-scale planetary waves arising from the baroclinic instability of an east-west zonal wind that includes a weak modulation in time. The finite-amplitude equilibration model is equivalent to the modulated Lorenz equations , containing an externally forced time-periodic Rayleigh parameter. Without modulation the baroclinic instabilities equilibrate to steady waves for all values of the external parameters reasonably near the linear neutral curve. However, a small modulation with a period of the same order as the internal dynamical timescale can completely destabilize the non-linear system, leading to chaotic solutions even for small supercriticality. Low-frequency seasonal modulations give rise to tori in the solution phase space. As the amplitude of the periodic forcing increases to about 10% of the average zonal wind shear, the tori break up and chaotic orbits are again found. This latter behavior is interpreted by studying the effect of seasonal forcing on the adiabatic invariants of the system.
Special Issue: Population and Development: Comparative Anthropological Perspectives

In this introduction, we do five things. First, we briefly review some of the contributions that anthropology has made in recent decades to the study of development. Second, we discuss the overall importance of population processes in development. Third, we provide an introduction to the field of anthropological demography. While each of these sections is necessarily brief, they are meant to situate the articles in this issue, placing them in a broad framework that suggests the contributions that anthropology can make to the study of comparative international development in general, and to the relationship between population and development in particular. To this end, the fourth aim of this introduction is to consider how anthropology approaches the social science task of comparison. Familiarizing readers with this engagement will, we hope, help in thinking about the contributions of the papers in this issue. The final section provides a brief introduction to each article, suggesting some of the ways they intersect with and illuminate themes we have raised here.
Trust as a Tactic: The Calculative Induction of Reciprocity

The current research uses the now-classic Trust Game and introduces a new, simultaneous version of the game to investigate whether people display trust as an influence tactic. Purely personal trusting decisions should lead trustors to send equivalent amounts in both versions of the game; calculative trusting decisions should lead to more trusting action when trustors know that trusted parties will see their behavior before choosing how to respond. Three studies observed considerable evidence of calculative trust that was particularly effective in generating reciprocity when trustors took greater risks and trusted more rather than less. These effects surfaced in social and exchange-oriented interactions, independently of a trustor's verbal messages, even when less costly, more direct means for creating trust were available. Analyses also indicated that feelings of obligation to reciprocate mediated these effects. Thus, it appears that trust tactics speak louder than words and, when they speak, people listen.
Anomalaspis Ambiguus Brennan, 1952 Redescribed and the Questionable Association of South American Species with Pseudoschoengastia (Acarina: Trombiculidae)

A recently discovered second specimen of Anomalaspis ambiguus has prompted redescription of the species. South American species questionably associated with the genus Pseudoschoengastia are considered.
Performance properties of polymer modified asphalt binders containing wax additives

Abstract The study presents an experimental evaluation of the rheological properties of control and polymer modified asphalt (PMA) binders containing wax additives and a comprehensive comparison between these two binder types. The control and PMA binders with the additives were produced using two of the available warm asphalt processes (i.e., LEADCAP and Sasobit) and then artificially short-term and long-term aged using the rolling thin film oven (RTFO) and pressure aging vessel (PAV) procedures. Superpave binder tests were carried out on the binders through the rotational viscometer (RV), the dynamic shear rheometer (DSR), and the bending beam rheometer (BBR). In general the results of this study indicated that (1) the addition of wax additives into the control and PMA binders decreases the viscosity, as expected; (2) the reduction rate of viscosity was quite similar for both the binders with wax additives; (3) the percentage increase of rutting resistance due to the additives was much higher for the control binder, compared to the PMA binder; (4) both the control and PMA binders showed the similar trends in terms of fatigue cracking and low temperature cracking behavior after the addition of wax additives.
Smart Icon Cards.

Icons are frequently used in the music classroom to depict concepts in a developmentally appropriate way for students. SmartBoards provide music educators yet another way to share these manipulatives with students. This article provides a step-by-step tutorial to create Smart Icon Cards using the folk song “Lucy Locket.”
Septic shock in obstetrics.

Septic shock in Obstetrics is an uncommon yet potentially lethal complication of infection. Differences in potential pathogens and physiologic alterations associated with pregnancy may alter the presentation and outcome of this problem. Optimal therapy should be directed at reestablishing an effective intravascular volume, maintaining adequate oxygen delivery to peripheral and central tissues, and initiating appropriate broad-spectrum antimicrobial agents to eradicate the causative pathogens.
Discussing underrepresentation as a means to facilitating female students' physics identity development

Explicit discussions of the underrepresentation of women in science can change the way that female students interpret their experiences and potential futures as scientists.
Studies of Evolving Carbohydrate Metabolism in vivo by 13C Surface-Coil NMR Spectroscopy

The capability of NMR spectroscopy to study biological systems noninvasively was extended to whole animal applications by the introduction of the surface-coil receiver by Ackerman et al. (1980). While this first demonstration utilized a 31P-tuned receiver for the detection of phosphorus signals, the technique has been extended to other nuclides, including proton ( 1H) and fluorine (19F), and, in conjunction with proton-decoupling, carbon ( 13C).
Knee Rotation: The Torg School

Dr. Joseph Torg made great advances in the diagnosis and understanding of anterior cruciate ligament (ACL) injury in 1976 with the publishing of his landmark paper, “Clinical diagnosis of anterior cruciate ligament instability in the athlete.” This publication defined the proper execution of the Lachman test, which is a variation of the more commonly utilized anterior drawer test, in diagnosing anterior cruciate ligament ruptures. At the time of publication, the ACL was thought to hold little importance, primarily due to an inability to effectively and consistently diagnose isolated rupture patterns and therefore, a lack of understanding of the ACL’s important role in joint stability. Torg purported the Lachman test as a way to overcome the difficulties in accurately diagnosing ACL insufficiency by resolving the problems commonly encountered when performing the anterior drawer test. A decade after initial introduction of the Lachman test, Torg and colleagues further defined a specific grading system for the Lachman test using a knee arthrometer. This allowed for a quantitative assessment of joint instability and, subsequently, outlined specific treatment protocols based on the relative severity of the injury. In the years following these publications, multiple other studies have supported the accuracy of the Lachman test in diagnosing isolated ACL ruptures, solidifying the importance of the test in the clinical setting.
Theoretical analysis of modulation doping effects on intersubband transition properties of semipolar AlGaN/GaN quantum well

The effects of modulation doping on the intersubband transition (ISBT) properties of semipolar AlGaN/GaN quantum well (QW) are investigated theoretically using QW doping, barrier doping, and barrier δ-doping schemes at 150 K. Important ISBT parameters such as intersubband transition energies, dipole matrix elements, and absorption spectra are calculated for QW structures on both semipolar ( 20 2 ¯ 1 ) (i.e., with weak polarization) and ( 10 1 ¯ 3 ) (i.e., with strong polarization) planes. For ( 20 2 ¯ 1 ) QW with weak polarization, it is found that high doping concentrations can cause a significant band bowing to the QW structures, which reduce the absorption coefficients and wavelengths. This band bowing effect will become stronger when doping layers are closer to the QW. For ( 10 1 ¯ 3 ) QW with a strong polarization, however, a weak band bowing effect is observed due to the large polarization and large band tilting of ( 10 1 ¯ 3 ) QW. The study shows that modulation doping is a promising method to modi...
The Central Role of Endothelial Dysfunction in Cardiorenal Syndrome

Background: Endothelial dysfunction (ED) has emerged as a critical process in cardiorenal syndrome (CRS). The concept that ED is closely linked with cardiac and r
Biomarkers of Calcific Aortic Valve Disease

Calcific aortic valve disease (CAVD) is a highly prevalent cardiovascular disorder accounting for a rising economic and social burden on aging populations. In spite of continuing study on the pathophysiology of disease, there remain no medical therapies to prevent the progression of CAVD. The discovery of biomarkers represents a potentially complementary approach in stratifying risk and timing of intervention in CAVD and has the advantage of providing insight into causal factors for the disease. Biomarkers have been studied extensively in atherosclerotic cardiovascular disease, with success as additive for clinical and scientific purposes. Similar research in CAVD is less robust; however, the available studies of biomarkers in CAVD show promise for enhanced clinical decision making and identification of causal factors for the disease. This comprehensive review summarizes available established and novel biomarkers in CAVD, their contributions toward an understanding of pathophysiology, their potential clinical utility, and provides an outline to direct future research in the field.
Predicting the Nucleation Induction Time Based on Preferred Intermolecular Interactions

A key challenge in rationally designing heterogeneous surfaces for controlling crystallization is overcoming the lack of understanding the influence of surface properties has on nucleation. Previous studies have shown how surface chemistry can be used to control both nucleation rate and polymorphism. However, these approaches are often empirical and lack any predictive capability. Herein, a novel method, PETI (Predicting Efficacy Through Intermolecular Interactions), for predicting the effectiveness of different polymer surfaces in promoting heterogeneous nucleation is described. PETI utilizes the Cambridge Structural Database to determine the likelihood of forming an intermolecular interaction between solute chemical moieties and polymer surfaces. The concept for PETI is the more likely a solute/polymer interaction, the faster the rate of heterogeneous nucleation. PETI was tested by studying the nucleation of model compounds, benzocaine and 1,1′-bi-2-naphthol, on different polymer surfaces. Results showe...
Testing Strong and Weak Gauge Theories in Quarkonium Decays

We believe we may have discovered the right gauge theories of both the weak and the strong interactions. However, there is a whole class of processes in which the predictions of these gauge theories have hardly been tested at all. These are the flavor-preserving nonleptonic weak interactions, such as the weak contribution to proton-proton scattering. Being purely hadronic, these processes are weak interactions among quarks, modified by the QCD strong interactions which bind those quarks into hadrons. Thus, they are very difficult to calculate. Being flavor-preserving, these weak interactions have to compete with strong and electromagnetic interactions. Thus, they lead in general to very tiny effects which are almost impossible to see. Consequently, not very much is known about them, although we do have some information from the experiments on parity-violation in nuclei.
Aging and the Decline of Androgen Production

Human male aging is associated with progressive decreases in serum concentrations of testosterone, which are not in response to decreased circulating basal luteinizing hormone (LH) concentrations, suggesting that reduced testosterone results from a primary deficit at the gonadal rather than the hypothalamic-pituitary level. This also is true of Brown Norway rats, a strain that has become widely used for studies of Leydig cell aging. Age-related reduced testosterone was found to result from reduced Leydig cell steroidogenesiss, but not by their loss. This chapter deals with the cellular changes, which are associated with reduced testosterone, and their causes. Age-related reductions have been reported in Leydig cell LH receptor numbers, intracellular cyclic adenosine monophosphate (cAMP) formation, steroidogenic acute regulatory protein, peripheral benzodiazapine receptor, the conversion of cholesterol to pregnenolone within the mitochondria and the subsequent conversion of pregnenolone to progesterone, 17a-hydroxyprogesterone, androstenedione, and ultimately testosterone in the smooth endoplasmic reticulum. Culturing isolated Leydig cells with LH maintained high levels of testosterone production by young cells but did not restore old cells to “young” levels. In contrast, culturing old cells with dibutyryl cAMP restored testosterone production to high levels, suggesting a deficit in the signal transduction mechanism between the LH receptor and cAMP production. Long-term suppression of steroidogenesis, accomplished by administering exogenous testosterone to middle-aged rats, prevented the steroidogenic aging of the cells, suggesting that ultimately steroidogenesis itself might result in age-related reductions in steroidogenesis. As measured with lucigenin, reactive oxygen production by old Leydig cells was found to be significantly more than by young Leydig cells. Microarray and Northern blot analysis revealed that the expression of genes for Cu-Zn Superoxide dismutase 1, Cu-Zn Superoxide dismutase 2, catalase, and glutathione peroxidase, the products of which protect Leydig cells from oxidative stress, are reduced as the Leydig cells age, as does their activities and protein levels. Depletion of glutathione with buthionine sulfoximine resulted in reduced testosterone production by young adult Leydig cells. Incubation of the cells with vitamin E delayed reduced testosterone production. Taken together, the available data suggests that changes in reactive oxygen and thus, an altered redox environment in aging Leydig cells might cause the changes in Leydig cells that result in age-related reduced testosterone production, and that the reactive oxygen might derive, at least in part, from steroidogenesis itself.
Alternating Skew on Lateral Gaze: Neuroanatomic Pathway and Relationship to Superior Oblique Overaction

Background: Previous studies of patients with heterogeneous, often diffuse neurologic disorders concluded that the neurologic substrate for alternating skew on lateral gaze may be localized at the level of the brain stem tegmentum or the cervico-medullary junction, or both. The localized nature of brain tumors offers an opportunity to further investigate the anatomic localization for this as well as other conditions. Methods: To test the hypothesis that cervico-medullary and cerebellar lesions are responsible for alternating skew on lateral gaze, the authors investigated a series of 50 children with brain tumors, 39 of whom showed neuro-ophthalmologic abnormalities on clinical testing. Seven children had alternating skew on lateral gaze. Results: All seven children with alternating skew on lateral gaze showed neoplastic involvement at the level of the cervico-medullary junction and/or the cerebellum on critical analysis of neuro-imaging studies. Conclusion: The authors conclude that the neuroanatomic substrate for alternating skew on lateral gaze is localized at the level of the cervico-medullary junction and/or the cerebellum. Knowing that (1) alternating skew on lateral gaze closely mimics superior oblique overaction clinically, (2) superior oblique overaction is frequently found in patients with myelomeningocele, and (3) myelomeningocele is uniformly associated with ArnoldChiari type II which includes cerebellar and cervico-medullary region abnormalities, the authors propose that alternating skew on lateral gaze and superior oblique overaction associated with myelomeningocele have similar neuroanatomic pathways.
Phylogeny and Ontogeny of the Renin-Angiotensin System

Renin substrate in plasma, biological renin activity, and/or granulated cells in the kidney evolved at an early stage of vertebrate phylogeny. Angiotensin (Ang) I and II molecules have been biochemically identified in representative species of all vertebrate classes, and Ang II structure is well preserved throughout the phylogenetical scale. Ang receptors have also been identified pharmacologically and, in limited species, molecularly characterized. The renin-angiotensin system (RAS) is important in maintaining blood pressure/blood volume homeostasis and ion-fluid balance. Recently, the regulatory role of Ang in cell growth and vascularization, possibly via paracrine action, has been an intensive focus of research. The RAS has been detected during early fetal development, and genetic or pharmacological blockade of Ang signaling results in striking developmental abnormalities of the kidney. This chapter will provide: (1) a brief overview of current knowledge of RAS phylogeny and ontogeny; (2) a comparison of these two systems in terms of structural, biochemical, and functional properties of each component of the RAS; and (3) perspectives for future study. Discussions are focused on: (1) the most fundamental functions of the RAS that have been conserved throughout phylogenetical advancement as well as developmental maturation; (2) the physiological significance of the shifting of expression of renin-producing cells in the renal arterial trees with vertebrate advancement or ontogenic maturation; and (3) the roles of environments, or microenvironments, in modulating the expression of component members of the RAS during phylogenetic and ontogenic processes. Although ontogeny does not directly recapitulate phylogeny, comparison of these two time-dependent processes should provide new insight into the molecular and functional evolution and significance of the RAS.
Qualitative Stability of Ecosystem Models

By virtue of the first law of thermodynamics, energy is conserved in ecosystems. Certainly ecosystem models based on energy flow should conserve energy. However, it is generally regarded as very difficult or impossible to specify exactly all the significant energy flow rates in an ecosystem, so every model inherently involves simplifications and approximations of nature. We know that the flow rates must “add up” so that energy is conserved; that is, for every compartment energy input minus energy output must exactly equal energy change. But we often do not know precisely the energy flow rates.
Determination of Molecular Ion Structures by Photoelectron Spectroscopy

Let us differentiate at the outset between photoelectron spectroscopy (PES) and photoionization mass spectrometry (PIMS). In PES a fixed wavelength of light (most commonly the He I resonance line at 584A = 21.2 eV) crosses a molecular target, causing some ionization. The kinetic energies of electrons thus liberated are measured by an electron energy analyzer.
Imaging of renal cancer using positron emission tomography with 2-deoxy-2-(18F)-fluoro-D-glucose: pilot animal and human studies.

AbstractThe feasibility of imaging renal cancers with 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) and whole-body positron emission tomographic scanning was assessed in nude mice with human renal adenocarcinoma xenografts and then in 5 patients with primary renal cancer (4 adenocarcinomas and 1 transitional cell carcinoma). In nude mouse biodistribution studies tumor FDG uptake was maximal at 0.33 to 2 hours but tumor-to-blood ratios increased continuously to 7.8/1. by 4 hours after intravenous FDG injection. In all 5 patients primary and metastatic tumors were imaged within 1 hour by FDG positron emission tomography following intravenous injection of the FDG. By contrast, an hepatic hemangioma did not accumulate FDG. In summary, FDG metabolic and anatomical imaging of primary and metastatic renal cancer is feasible and in these pilot studies appears to be a promising imaging methodology that may be further enhanced by delayed imaging times. Additional study in a larger number of patients is essential to define...
Alternate Cellular Models for Aging Studies

Studies such as those described by Drs. Macieira-Coelho and Mitsui lead to increased insignt into the mechanisms of the limited proliferative capacity of human diploid fibroblasts. While I suggest that these elegant studies of the in vitro passage of human cells be continued, I urge the development of alternate models for the study of cellular aging. In our laboratory, we have examined human diploid cells as a function of in vitro passage and the age of the donor of these cells. The first studies in this latter area were conducted by Drs. Hayflick, Goldstein, Martin, and their co-workers (1–3). These investigators demonstrated the diminished proliferative potential of cell cultures with the increasing age of the donor. At the Gerontology Research Center in Baltimore, we have been fortunate to be able to conduct our studies on skin fibroblast cultures derived from young and old volunteer members of the Baltimore Longitudinal Study. We have examined the total replicative ability of these skin fibroblast cultures, as well as many of the parameters analyzed by Drs. Mitsui and Macieira-Coelho as a function of in vitro passage (4).
Development of a Chinese and American scale for measuring spirituality

AbstractA consensus has not been reached on the definition of spirituality. Consequently, it is difficult to understand the concept and to develop scales to assess spirituality. To measure this concept in a non-Western culture is even more difficult. Following sound scale development procedures, the current study endeavors to develop a Spirituality Scale for College Students that could apply to both Chinese and American college students. The scale focuses on three core aspects of spirituality. Data were collected from college students both in China and the U.S. to provide validity and reliability evidence. The results showed that a three-factor model fit the American sample, the Chinese sample, and the entire sample. A measurement invariance analysis revealed that the scale achieved partial measurement invariance. Implications and limitations are also discussed.
Voltage tuning of reflectance from a strongly coupled metasurface-semiconductor hybrid structure (Conference Presentation)

Metasurfaces have been investigated for various applications ranging from beam steering, focusing, to polarization conversion. Along with passive metasurfaces, significant efforts are also being made to design metasurfaces with tunable optical response. Among various approaches, voltage tuning is of particular interest because it creates the possibility of integration with electronics. In this work, we demonstrate voltage tuning of reflectance from a complementary metasurface strongly coupled to an epsilon-near-zero (ENZ) mode in an ultrathin semiconductor layer. Our approach involves electrically controlling the carrier concentration of the ENZ layer to modulate the polaritonic coupling between the dipole resonances of the metasurface and the ENZ mode for modulating the reflectance of the metasurface. The hybrid structure we fabricate is similar to MOSCAP configuration where the complementary metasurface offers a continuous gold top layer for biasing and positive/negative bias to the metasurface leads to accumulation/depletion of carriers in the ENZ layer beneath it. We optimized our structure by using InGaAs as the ENZ material because of its high mobility and low effective mass. This allowed us to reduce the doping requirement and thereby reduce the ionized impurity scattering as well as the reverse bias required to deplete the ENZ layer. For low leakage and efficient modulation of carrier density, we used Hafnia as the gate dielectric. We further added a reflecting backplane below the ENZ layer to enhance the interaction and by applying bias, we achieved spectral shifts of 500 nm and amplitude modulation of 11% of one of the polariton branches at 14 µm.
Digital survivance and Trickster humor: exploring visual and digital Indigenous epistemologies in the #NoDAPL movement

The decolonizing turn in the humanities and social sciences calls for scholarship that analyzes social media practices through the lens of Indigenous epistemologies. In this article, we model the w...
Aminonitro Groups Surrounding a Fused Pyrazolotriazine Ring: A Superior Thermally Stable and Insensitive Energetic Material

Nitrogen-rich heterocyclic compounds offer promising potential backbones for constructing various high energy density compounds. Selective diazotization of 3,5-diamino-4-nitropyrazole (1) with tert...
Mastery and Longevity in Spousal Caregivers of Persons with Dementia.

Objective Researchers have consistently shown that providing care in a gradually deteriorating situation, such as dementia, can be stressful and detrimental to the caregiver's (CG) health. Although stressor appraisal is important in understanding variability in CG outcomes, the role of personal mastery, a coping resource, in shaping CG's health outcomes has not been considered. The primary goal of this paper was to determine whether personal mastery is associated with a survival advantage for spousal CGs of persons with dementia. Methods This study assessed the association of CG burden and personal mastery with longevity over a 10-year period in 71 spousal CGs of persons initially diagnosed with mild cognitive impairment. Results Over the 10 years, 16 of 71 CGs (23%) died. Cox regression models with right censoring of CGs' time to death showed that after adjusting for the health of family CG, spousal CGs who reported high levels of burden had an 83% reduced risk of death when they also reported high personal mastery (hazard ratio [HR] = 0.17, 95% confidence interval [CI] 0.04, 0.65). Conclusions Findings have implications for support programs that help build personal mastery.
Imprints of mass accretion history on the shape of the intracluster medium and the TX–M relation

We use a statistical sample of galaxy clusters from a large cosmological $N$-body$+$hydrodynamics simulation to examine the relation between morphology, or shape, of the X-ray emitting intracluster medium (ICM) and the mass accretion history of the galaxy clusters. We find that the mass accretion rate (MAR) of a cluster is correlated with the ellipticity of the ICM. The correlation is largely driven by material accreted in the last $\sim 4.5$~Gyr, indicating a characteristic time-scale for relaxation of cluster gas. Furthermore, we find that the ellipticity of the outer regions ($R\sim R_{\rm 500c}$) of the ICM is correlated with the overall MAR of clusters, while ellipticity of the inner regions ($\lesssim 0.5 R_{\rm 500c}$) is sensitive to recent major mergers with mass ratios of $\geq 1:3$. Finally, we examine the impact of variations in cluster mass accretion history on the X-ray observable-mass scaling relations. We show that there is a {\it continuous\/} anti-correlation between the residuals in the $T_x-M$ relation and cluster MARs, within which merging and relaxed clusters occupy extremes of the distribution rather than form two peaks in a bi-modal distribution, as was often assumed previously. Our results indicate the systematic uncertainties in the X-ray observable-mass relations can be mitigated by using the information encoded in the apparent ICM ellipticity.
The Father of the Forest: Identity Formation and Hemingway’s Naturalist Calling

Critical inquiry shifts from the mother-son and sibling-twin dyads to Hemingway’s troubled yet generative relationship with his father, Ed—assessing its implications for the development of his identity and art. The origins of Hemingway’s identity as a naturalist/frontier scout are traced to the influence of his father, and his father’s veneration of the naturalist Louis Agassiz. This inquiry serves as a springboard into analysis of a father figure’s influence: the naturalist Carl Akeley, as a corrective to this under-theorized aspect of Hemingway studies. Akeley’s influence is read through the critical lens of Donna Haraway’s “Teddy Bear Patriarchy” in Primate Visions.
An Enzyme Activity from Escherichia coli That Attacks Single-Stranded Deoxyribopolymers and Single-Stranded Deoxyribonucleic Acid Containing Apyrimidinic Sites

We have isolated an enzyme activity from extracts of Escherichia coli that catalyzes the hydrolysis of phosphodiester bonds in the single-stranded deoxyribopolymer (dU.(/sup 3/H)dT)/sub (2000)/ containing depyrimidinated sites created by enzymatic removal of uracil with uracil-DNA glycosylase. Nondepyrimidinated polymer is not degraded by the enzyme, nor is the depyrimidinated polymer degraded after reduction of apyrimidinic sites with sodium borohydride. The enzyme also degrades circular M18 DNA containing uracil or denatured phage PBS2 DNA (which naturally contains uracil) only after the removal of uracil from these substrates by uracil-DNA glycosylase. Undamaged or depurinated duplex PM2 or ColEl DNA and undamaged M13 single-stranded DNA are not attacked by the enzyme. The activity sediments in glycerol gradients with a relative s value of 4.2 S and has a Stokes radius of 31 angstrom, yielding a calculated M/sub r/approx.56000. The fractional ratio (f/fo) is calculated at 1.25. The enzyme has no requirement for any known cofactors and is insensitive to inhibition by p-(chloromercuri)benzoate. Activity is inhibited in the presence of adenosine 5'-triphosphate (ATP), tRNA, or high ionic strength and is slightly stimulated by MnCl/sub 2/ or CaCl/sub 2/.
Ex vivo kidney slice preparations as a model system to study signaling cascades in kidney epithelial cells.

Abstract Several model systems have been used to study signaling cascades in kidney epithelial cells, including kidney histology after systemic treatments, ex vivo isolated tubule perfusion, epithelial cell lines in culture, kidney micropuncture, and ex vivo kidney slices. We and others have found the ex vivo kidney slice method useful to study the signaling cascades involved in the regulation of kidney transport proteins. In this chapter we describe our adaptations to this classic method for the study of the regulation of kinases and endocytosis in rodent kidney epithelial cells. Briefly, slices are obtained by sectioning of freshly harvested rat or mouse kidneys using a Stadie-Riggs tissue slicer. Alternatively, a vibratome can be used to obtain slices at a more consistent and finer thickness. The harvested kidney and kidney slices are kept viable in either cell culture media or in buffers that mimic physiological conditions equilibrated with 5% CO2 at body temperature (37 °C). These buffers keep the slices viable during hours for incubations in the presence/absence of different pharmacological agents. After the incubation period the slices can be used for biochemistry experiments by preparing tissue lysates or for histological evaluation after fixation. Moreover, the fixed slices can be used to evaluate changes in subcellular trafficking of epithelial proteins or endosomes via immunolabeling followed by confocal microscopy. The resulting micrographs can then be used for systematic quantification of protein- or compartment-specific changes in subcellular localization under each condition.
Few Shot Learning For Point Cloud Data Using Model Agnostic Meta Learning

The ability of deep neural networks to extract complex statistics and learn high level features from vast datasets is proven. Yet current deep learning approaches suffer from poor sample efficiency in stark contrast to human perception. Few shot learning algorithms such as matching networks or Model Agnostic Meta Learning (MAML) mitigate this problem, enabling fast learning with few examples. In this paper, we extend the MAML algorithm to point cloud data using a PointNet Architecture. We construct N$\times$K-shot classification tasks from the ModelNet40 point cloud dataset to show that this method performs classification as well as supervised deep learning methods with the added benefit of being able to adapt after a single gradient step on a single N$\times$K task. We empirically search for optimal values of N and K for few shot classification and show our method to achieve 90% meta test accuracy compared to traditional PointNet with 89.2%. We also adapt a meta-trained PointNet to a support set of 9, N=3, K=3, never before seen point clouds which are drawn from an entirely different dataset, ShapeNet. Once adapted the model achieves 7.1/9 classification accuracy on average across 100 query sets of the same classes with new, unique instances. This result far exceeds the supervised Stochastic Gradient Descent (SGD) training result of 3.1/9 accuracy on the query sets which is equivalent to a random baseline.
A Privacy-Preserving Collaborative Caching Approach in Information-Centric Networking.

It has been established that in-network caching in an Information-Centric Network (ICN) environment significantly reduces required bandwidth and content retrieval delay, and reduces load on content producers. However, malicious actors masquerading as legitimate consumers can probe cache contents and use the resultant data to map content objects to, and thereby violate the privacy of, the consumer(s) who requested them. Existing mitigation approaches suffer a direct trade-off between privacy and utility; the two are diametrically opposed, and prioritizing either rapidly degrades its counterpart. This paper presents a collaborative caching approach with provable privacy and utility guarantees that instead monotonically increase as a function of one another, growing in tandem. Our proposed scheme preserves all true cache hits to utilize in-network caching as efficiently as possible. We have evaluated our method against a number of other in ICN caching policies for a variety of workloads and topologies. Our results show that our technique delivers high cache hit ratios and minimizes interest satisfaction delay while offering provable privacy guarantees.
Overall Capacity Assessment of Distribution Feeders with Different Electric Vehicle Adoptions

An overall capacity assessment and an analysis of the system’s X/R ratios for six actual distribution feeders was conducted to characterize the voltage response to various levels of distributed Electric Vehicle Supply Equipment (EVSE). The evaluation identified the capacity of the system at which a voltage violation occurred. This included a review of the uncontrolled and controlled cases to quantify the value of injecting reactive power as the grid voltage decreases. The evaluation found that the implementation of a Volt-Var curve with a global voltage reference provided a notable increase in capacity. A local reference voltage, measured at the point of common coupling, did not increase the capacity of every feeder in the experiment. The review of the X/R line properties using a Principal Component Analysis (PCA) identified groups within the six feeders that corresponded with each system’s voltage response rate. This suggests the X/R ratios provide a direct prediction of the feeder’s ability to avoid voltage violations while charging EVs.
Temperature in Nursing Home Residents Systematically Tested for SARS-CoV-2

Background: Many nursing home residents infected with SARS-CoV-2 fail to be identified with standard screening for the associated COVID-19 syndrome. Current nursing home COVID-19 screening guidance includes assessment for fever defined as a temperature of at least 38.0°C. We evaluated the temperature before and after universal testing for SARS-CoV-2 in nursing home residents. Methods: The Veterans Administration (VA) operates 134 Community Living Centers (CLC), similar to nursing homes, that house residents who cannot live independently. VA guidance to CLCs directed daily clinical screening for COVID-19 that included temperature assessment. All CLC residents underwent SARS-CoV-2 testing once testing capacity could accommodate it. We report the temperature in the 14 days before and after universal SARS-CoV-2 testing among CLC residents. Findings: Among the 7325 CLC residents, SARS-CoV-2 was identified in 443 (6.0%). The average maximum temperature in SARS-CoV-2 positive residents was 37.66 (0.69) compared to 37.11 (0.36) (p=0.001) in SARS-CoV-2 negative residents. Temperatures in those with SARS-CoV-2 began rising 7 days prior to testing and remained elevated during the 14-day follow up. Among SARS-CoV-2 positive residents, only 26.6% (n=118) met the fever threshold of 38.0°C during the survey period. Most residents (62.5%, n=277) with confirmed SARS-CoV-2 did experience two or more 0.5°C elevations above their baseline values. One cohort of SARS-CoV-2 residents’ (20.3%, n=90) temperatures never deviated >0.5°C from baseline. Interpretation: A single screening for temperature is unlikely to detect nursing home residents with SARS-CoV-2. Repeated temperature measurement with a patient-derived baseline can increase sensitivity. The current fever threshold as a screening criteria for SARS-CoV-2 infection should be reconsidered. Funding Statement: This work was funded by VA Health Services Research and Development and the National Institute of Aging 3P01AG027296-11S2 Declaration of Interests: The authors have declared no conflicts. Ethics Approval Statement: This study was approved by the Providence VAMC Institutional Review Board.
Balancing energy expenditure and storage with growth and biosynthesis during Drosophila development.

Abstract Sustaining life requires efficient uptake of nutrients and conversion to useable forms. Almost everything about this process is dynamic. Nutrient availability fluctuates and changing environmental conditions impose new demands that can tip the metabolic equilibrium from biosynthesis and macromolecule storage to energy expenditure. At the same time, the organism itself changes, particularly during the rapid growth and differentiation in early development and also later in life as the adult ages. Here we review what has been learned from Drosophila melanogaster as an experimental model about the connections between external signals, signaling pathways, tissues and organs that allow animals to balance energy storage with expenditure in the face of change, both intrinsic and extrinsic.
Maternal, neonatal and placental characteristics of SARS-CoV-2 positive mothers.

COVID19 is caused by a newly identified severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) that affects pregnant women equally to the general population. How SARS-CoV2 affects the mothers,...
Move to See Better: Self-Improving Embodied Object Detection

Passive methods for object detection and segmentation treat images of the same scene as individual samples and do not exploit object permanence across multiple views. Generalization to novel or difficult viewpoints thus requires additional training with lots of annotations. In contrast, humans often recognize objects by simply moving around, to get more informative viewpoints. In this paper, we propose a method for improving object detection in testing environments, assuming nothing but an embodied agent with a pre-trained 2D object detector. Our agent collects multi-view data, generates 2D and 3D pseudo-labels, and fine-tunes its detector in a self-supervised manner. Experiments on both indoor and outdoor datasets show that (1) our method obtains high-quality 2D and 3D pseudo-labels from multi-view RGB-D data; (2) fine-tuning with these pseudo-labels improves the 2D detector significantly in the test environment; (3) training a 3D detector with our pseudo-labels outperforms a prior self-supervised method by a large margin; (4) given weak supervision, our method can generate better pseudo-labels for novel objects.
Green syntheses of stable and efficient organic dyes for organic hybrid light-emitting diodes

Organic hybrid light-emitting diodes (hybrid-LEDs) employ organic dyes as light converters on top of commercial blue inorganic LEDs, replacing incumbent inorganic phosphor light converters synthesized from rare-earth and/or toxic metallic elements to optimize device environmental sustainability. Here, we present two naturally derived organic dyes for hybrid-LEDs, highlighting stability and efficiency enhancement based on a novel “acceptor–acceptor” molecular design. This “acceptor–acceptor” skeleton comprises theobromine and thiadiazole, two electron-withdrawing groups that lower energy levels and suppress photooxidation. This differentiates these dyes from the widely adopted “donor–acceptor” skeleton, where photooxidation is facilitated by the presence of electron-donating units. Simultaneously, sidechains on organic dyes used to enhance solution processability, crucial for film transparency, introduce an additional photooxidation pathway. With this “acceptor–acceptor” skeleton, the destabilization from sidechains was offset by the stability enhancement from the electronic effects in the backbone. When blended within an industrial polymer, poly(styrene-butadiene-styrene) (SBS), their enhanced solubility enables the formation of highly transparent films, crucial for reducing scattering loss in LEDs. Furthermore, resultant dye-SBS films achieved photoluminescence quantum yields (PLQYs) of around 90% under ambient conditions. Taking advantage of their transparency and solution processability, we fabricated a waveguide with this theobromine-dye-SBS composite, which was subsequentially assembled into an edge-lit LED device of no glare and enhanced aesthetics.
New Insights into Metabolic Regulation from Hyperpolarized 13 C MRS/MRI Studies

Much of our knowledge of the biochemical pathways we refer to as intermediary metabolism was derived from studies of isolated enzymes, organelles, and cells using radioactive tracers. With advancements in NMR technology and the commercial availability of 13C-enriched compounds as biochemical tracers, we are gaining new insights into the complexities of metabolism not only at the cellular level but now in human subjects. After the demonstration that dynamic nuclear polarization methods can be used to create highly polarized 13C samples ready for injection into animals or human subjects, one can begin to obtain enough kinetic details to measure flux not only through extended pathways but also through individual enzyme-catalyzed steps along a metabolic pathway. In this chapter, we illustrate several examples of using hyperpolarized 13C tracers to measure flux through competing pathways in isolated perfused rodent hearts and livers and in living animals. Even though multiple oxidizable substrates (glucose, fats, and ketones) are always available to tissues in vivo, presentation of a highly polarized substrate such as pyruvate to tissues while imaging downstream metabolic products derived from pyruvate can provide novel insights into metabolic regulation of competing pathways under variable nutritional states. This powerful feature of hyperpolarized 13C metabolic imaging offers considerable potential as a rapid, noninvasive tool for monitoring changes in metabolic flux as a tissue responds to dietary alterations or drugs. This new imaging method will add unique diagnostic information to the study of human diseases in the future.
VSS: A Storage System for Video Analytics

We present a new video storage system (VSS) designed to decouple high-level video operations from the low-level details required to store and efficiently retrieve video data. VSS is designed to be the storage subsystem of a video data management system (VDBMS) and is responsible for: (1) transparently and automatically arranging the data on disk in an efficient, granular format; (2) caching frequently-retrieved regions in the most useful formats; and (3) eliminating redundancies found in videos captured from multiple cameras with overlapping fields of view. Our results suggest that VSS can improve VDBMS read performance by up to 54%, reduce storage costs by up to 45%, and enable developers to focus on application logic rather than video storage and retrieval.
Tensile Properties of Additively Manufactured C-18150 Copper Alloys

The effect of aging processes on the tensile properties of C-18150 copper alloy samples, made by laser powder-bed-fusion additive manufacturing (AM) process with three different fabrication orientations (horizontal, angled, and vertical to the build direction), are investigated. For the as-fabricated C-18150 AM parts, horizontal and angled fabrication directions result in marginally better tensile strengths and much improved strain-to-failure values than those of vertically built AM parts. After the aging treatment, tensile strength can be significantly enhanced with a sacrifice of the strain-to-failure value. Moreover, the highest tensile strength is achieved by treating the as-fabricated samples at an aging temperature of 500 °C for 2 h. At 800 °F (427 °C), both tensile strength and ductility are smaller than low temperature values (room temperature and 400 °F/ 204 °C). Phase constituents, microstructure, and composition distribution of the AM parts are characterized to gain insight into the measured tensile properties.
Genotype-Guided vs Clinically-Guided Stable Warfarin Dose Prediction and Stable Dose Establishment In A Predominantly Non-European Ancestry Population

Warfarin dosing varies due to individual genetic and clinical factors. The utility of genotype‐guided warfarin dosing to improve stable warfarin dose is not extensively studied in non-European popu...