cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract SY21-02: DNA methylation and epigenetic instability in human cancer

Alterations in DNA methylation in human cancer were identified 30 years ago but a comprehensive view has emerged with the advent of whole genome bisulfite sequencing. While cancer can be viewed as over 200 distinct diseases that are organ-specific in their pathology, and mutation-specific in their molecular mechanism, recent discoveries in cancer epigenetics suggest a different but complementary view. Epigenetically, cancer may approach a single disorder with certain common features underlying the major reasons for cancer morbidity and mortality. Specifically, several common solid tumor types show increased epigenetic instability in DNA methylation at specific loci but involving the same loci in many different tumor types, and these loci appear to be critical for unregulated cell growth and tissue invasion and metastasis, and they involve the boundaries between CpG islands and shores, as well as large hypomethylated genomic blocks. These blocks correspond to large organized chromatin lysine (K) -modified domains (LOCKs) that are normally modulated during cellular reprogramming in development and epithelial-mesenchymal transition. We suggest a unifying model for the epigenetic basis of cancer in which increased instability in gene expression is mediated by loss in cancer of nuclear structures that control variance during normal development, such as LOCKs and CpG island boundaries. By this view, stochastic noise is a necessary part of cell fate determination leading to Waddingtonian canalization, and cancer is a disease, at least epigenetically, in which these canals are shallower, with increasing noise and the probability of cell type transitions that should not appear in differentiated tissues. At the same time, this increased noise increases the fitness of cancer cells and their resistance to any given therapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr SY21-02. doi:1538-7445.AM2012-SY21-02
Globalization: Political Aspects

The first two eras of globalization (in the sixteenth and nineteeenth centuries) are reviewed before stressing the leading role of the USA in this, the third era. The resistance to globalization is then examined, showing the prominent role of religious opposition, which in places coalesces with political/nationalist opposition (e.g., Eastern Orthodoxy, Hinduism). Together the sources of opposition comprise a vast region, all of Eurasia and more. The author notes that previous globalization eras have led to a clash of civilizations and war: there are great political risks inherent in the current process.
Improved Allograft Survival in Nonidentical Living Related Donor Transplants using Donor-Specific Blood Transfusions

AbstractA total of 78 consecutive HLA nonidentical living related donor transplant recipients with moderate to high stimulating mixed lymphocyte culture indexes underwent a deliberate donor-specific blood transfusion protocol. Of the patients 67 were first and 11 were second allograft recipients.Patients were monitored for immunological responses by cytotoxic B-cold, B-warm and T-warm antibody responses to a random panel of 30 donors, and by serial crossmatches to their donor subset B and T lymphocytes at 5C and 37C before beginning the protocol and after each donor-specific blood transfusion. Patients were followed from 3 months to 2½ years, with allograft survival rates reported by the actuarial method. Survival rates of first allograft recipients were 96.0 plus or minus 2.77, 93.97 plus or minus 3.37, 93.97 plus or minus 3.37 and 90.68 plus or minus 4.50 per cent at 3 and 6 months, and 1 and 2 years, respectively.Of the patients entering the protocol for a primary transplant 20.18 per cent had persiste...
Symbiotic Bacteria and Gut Epithelial Homeostasis

The resident microbiota of the mammalian intestine can influence a range of physiological functions including cellular proliferation, epithelial barrier function, and modulation of immune responses. The modulatory effects of commensal bacteria on inflammatory signaling networks have been widely studied; however, little is known about control over intestinal homeostasis. Our research group has recently reported that gut epithelia contacted with lactobacilli induces the cellular generation of reactive oxygen species (ROS). It is well established that professional phagocytes generate microbiocidal levels of ROS through the stimulation of formyl peptide receptors (FPRs) and activation of NADPH oxidase 2. However, bacterial-stimulated ROS generation has also been discovered in the intestinal epithelia, in response to microbial signals via FPRs and the epithelial NADPH oxidase 1 (Nox1). Physiological levels of ROS deliberately generated by cell types throughout the body are known to function as secondary messengers in signal transduction pathways. This occurs through the reversible oxidation of oxidant-sensitive thiol side groups of cysteine residues harbored within a distinct class of sensor proteins. Examples of redox-sensitive proteins include those that regulate the NF-κB pathway, MAP kinase pathways, and tyrosine phosphatases that serve as regulators of focal adhesion kinases. Indeed, cellular ROS generation in response to contact with lactobacilli has been experimentally shown to modulate innate immune signaling, enhance cell motility during wound restitution, and stimulate cellular proliferation. These findings establish that the positive physiological influences commensal bacteria on the intestine at least partly occur by a ROS-dependent mechanism.
INVARIANT RECOGNITION OF GEOMETRIC SHAPES

Publisher Summary In using geometrical figures to convey information, little use is made of the position or orientation of the figures. The information is contained in their shapes, which might be defined as those properties of a figure that are invariant under rigid-body motions. This chapter highlights the problem of classifying geometric figures without regard to their positions and orientations. In formulating pattern recognition problems, it is often convenient to distinguish two separate operations in the recognition procedure, namely, measurement and decision. The problem of measurement is to obtain from the sample to be classified a finite set of numbers that are indicative of the class to which the sample belongs. This operation has the dual function of data conversion and data reduction. The operation of decision consists of assigning the sample to one of the prescribed classes on the basis of the measured values.
Walking Bridges: Placing the Liberal Arts and Sciences between Secondary and Higher Education:

When are the most appropriate times to receive a liberal arts and sciences education? The liberal arts and sciences model is meant to achieve aims that include general cognitive abilities, moral an...
HIV Receptor antagonists block basal breast cancer and prostate cancer metastasis in vivo

C is a leading cause of death worldwide and accounted for 7.6 million deaths (around 13% of all deaths. With an estimated 258 000 deaths in 2008, prostate cancer is the sixth leading cause of death from cancer in men (6.1% of the total). Breast cancer claimed more than 458,000 lives last year. In most cases the death of patients is due to metastasis. The identification of new therapeutic targets and treatments to reduce tumor metastasis requires alternative interrogation approaches and alternative strategies. We have identified a new approach through blocking the tumor metastasis “homing” process, to essentially interfere with the tumor’s “GPS”. Interrogation of microarray analysis of 2,254 human breast cancers demonstrated increased expression of CCL5 and its receptor CCR5, but not CCR3, in the basal and HER-2 genetic subtypes of breast cancer. Genome wide interrogation of pathways activated in patient normal breast vs. tumor identified upregulation of a CCR5 signaling module. Human breast cancer cell lines expressed CCR5 by flow cytometry and displayed a functional response to CCL5 by calcium mobilization assays and invasion assays. Using isogenic oncogene transformed breast and prostate cancer cell lines we show oncogene transformation induces CCR5 expression and that the subpopulation of cells that express functional CCR5 display increased invasiveness. CCR5 promoted metastasis homing in vivo. The CCR5 antagonists Maraviroc or Vicriviroc, developed to block CCR5 HIV co-receptor function, reduced in vitro invasion of basal breast cancer and prostate cancer cell lines without affecting cell proliferation or viability. In a series of preclinical mouse models, Maraviroc decreased breast cancer pulmonary metastasis. The isogenic prostate cancer cell lines metastasized to bones and brain in immune-competent mice representing an ideal model for testing anti-metastasis therapies. Maraviroc or Vicriviroc, reduced prostate cancer metastasis to brain, bones and lungs. Our findings provide evidence for a key role of CCL5/CCR5 in the metastasis of basal breast cancer and prostate cancer cell lines and suggest that CCR5 antagonists may be used as an adjuvant therapy to reduce the risk of metastasis in patients with the basal breast cancer subtype and prostate cancer.
A method for bioinformatic analysis of transposon insertion sequencing (INSeQ) results for identification of microbial fitness determinants

Transposon insertion sequencing is a process whereby microbial fitness determinants can be identified on a genome-wide scale. This process uses high-throughput next generation sequencing to screen for changes in the composition of a pool of transposon mutants after exposure to selective conditions. One commonly used process for generating transposon insertion sequencing libraries is called INSeq that works with mutant pools produced using a modified Mariner transposon. Libraries produced using the INSeq process are sequenced on the Illumina platform. In this chapter, we describe our method for processing the raw Illumina sequencing reads, aligning the reads to a reference sequence to determine read counts, and using the online transposon insertion sequencing data analysis server, ESSENTIALS, to interpret the results.
Common path endoscopic probes for optical coherence tomography (Conference Presentation)

Background: Dispersion imbalance and polarization mismatch between the reference and sample arm signals can lead to image quality degradation in optical coherence tomography (OCT). One approach to reduce these image artifacts is to employ a common-path geometry in fiber-based probes. In this work, we report an 800 um diameter all-fiber common-path monolithic probe for coronary artery imaging where the reference signal is generated using an inline fiber partial reflector. Methods: Our common-path probe was designed for swept-source based Fourier domain OCT at 1310 nm wavelength. A face of a coreless fiber was coated with gold and spliced to a standard SMF-28 single mode fiber creating an inline partial reflector, which acted as a reference surface. The other face of the coreless fiber was shaped into a ball lens for focusing. The optical elements were assembled within a 560 µm diameter drive shaft, which was attached to a rotary junction. The drive shaft was placed inside a transparent sheath having an outer diameter of 800 µm. Results: With a source input power of 30mW, the inline common-path probe achieved a sensitivity of 104 dB. Images of human finger skin showed the characteristic layers of skin as well as features such as sweat ducts. Images of coronary arteries ex vivo obtained with this probe enabled visualization of the characteristic architectural morphology of the normal artery wall and known features of atherosclerotic plaque. Conclusion: In this work, we have demonstrated a common path OCT probe for cardiovascular imaging. The probe is easy to fabricate, will reduce system complexity and overall cost. We believe that this design will be helpful in endoscopic applications that require high resolution and a compact form factor.
Optimal Timing of Heart Transplant After HeartMate II Left Ventricular Assist Device Implantation.

Background Optimal timing of heart transplantation in patients supported with second-generation left ventricular assist devices (LVADs) is unknown. Despite this, patients with LVADs continue to receive priority on the heart transplant waiting list. Our objective was to determine the optimal timing of transplantation for patients bridged with continuous-flow LVADs. Methods A total of 301 HeartMate II LVADs (Thoratec Corp, Pleasanton, CA) were implanted in 285 patients from October 2004 to June 2013, and 86 patients underwent transplantation through the end of follow-up. Optimal transplantation timing was the product of surviving on LVAD support and surviving transplant. Results Three-year survival after both HeartMate II implantation and heart transplantation was unchanged when transplantation occurred within 9 months of implantation. Survival decreased as the duration of support exceeded this. Preoperative risk factors for death on HeartMate II support were prior valve operation, prior coronary artery bypass grafting, low albumin, low glomerular filtration rate, higher mean arterial pressure, hypertension, and earlier date of implant. Survival for patients without these risk factors was lowest when transplant was performed within 3 months but was relatively constant with increased duration of support. Longer duration of support was associated with poorer survival for patients with many of these risk factors. Device reimplantation, intracranial hemorrhage, and postimplant dialysis during HeartMate II support were associated with decreased survival. Conclusions Survival of patients supported by the HeartMate II is affected by preoperative comorbidities and postoperative complications. Transplantation before complications is imperative in optimizing survival.
Lexical access in English-Spanish bilinguals: A comparison of advanced heritage speakers and late learners

Does early onset age of language learning in an informal setting always have a long-term advantage? We compared lexical access in adult heritage speakers of Spanish and late learners of Spanish in two word-production tasks, while also considering the speakers’ oral proficiency in their non-dominant language. In all speakers, word recall in the picture-naming task was less accurate and slower than in the translation task. Heritage speakers and late learners of high Spanish proficiency level were different only in the translation task, where learners were faster than heritage speakers, which may be explained by their experience with translation of visual input. These findings suggest that for a non-dominant language, an early onset of learning does not provide an advantage, at least when high-proficiency bilinguals, high-frequency words, and behavioral measures are concerned. Oral proficiency matters most, as it correlates with frequency of language use.
Severe Renal Allograft Rejection Resulting from Lenalidomide Therapy for Multiple Myeloma: Case Report

Lenalidomide, a thalidomide analogue, is an immunomodulatory drug currently used as a chemotherapeutic agent in treating certain hematologic malignancies, including multiple myeloma. The antineoplastic effect of lenalidomide may be due to its ability to modulate different components of the immune system as well as its antiangiogenic, antiproliferative, and direct cytotoxic activity. Given its immunomodulatory effects, lenalidomide may potentially elicit unintended immune activity against allografts in solid organ transplant recipients. Here, we present a case of a renal transplant recipient who developed multiple myeloma after transplantation and was treated with the use of lenalidomide, which precipitated severe acute T-cell-mediated rejection. Lenalidomide was thought to be causative, and after cessation of the drug her renal function stabilized.
Perceptual Learning of Tooling Affordances of a Jointed Object via Dynamic Touch

We investigated whether perceptual learning via dynamic touch can facilitate the discovery of tooling affordances. Twelve blindfolded participants manipulated two structurally identical aluminum ob...
ER DEVICES FOR CONTROL OF SEISMICALLY EXCITED STRUCTURES

ABSTRACT This study illustrates the behavior of a closed-loop vibration control system making use of electrorheological electrorheological ( er ) devices. ER fluids exhibit damping and stiffness properties which can be modulated by orders of magnitude when subjected to strong electric fields (kV/mm). An increase in yield stress (from 0 to 3 kPa) is characteristically observed when the field is applied. A Lyapunov-based controller results in control decisions which are independent of the structural model, and are therefore insensitive to modeling errors. Structures operated according to the control rule maintain an anti-resonant condition. In order to capitalize on the unique properties of er materials in this application it is desirable that the material be configured in a device in such a way that when the device undergoes characteristic motions, the device forces can be modulated to a significant degree (a factor of 10 or more). Because the range of adjustable forces is closely linked to the ratio of finite field-controllable yield stresses to uncontrollable viscous stresses, it is desirable for controllable er dampers to operate at low flow rates. In addition to the range of available forces, er dampers should have a short characteristic time, low stored electrical energy, and forces high enough to be effective for the intended application. The er damper described herein features multiple concentric electrodes which are electrically in parallel, but may be hydraulically interconnected through multiple paths.
Some Physical Problems in Bioinformatics

Bioinformatics is a data driven field, in which a significant number of problems require statistical modeling. The flood of data emerging from genome centers uses sequence comparison to delimit and assign function to genes, and in very limited ways infers gene control from approximately repeated sequence motifs near to the genes themselves. Traditional topics in computer science such as coding theory, natural language processing, and old fashioned cryptography all impinge on the problem of deducing regulatory information from the genome, but are not probabalistic enough to cope with the fuzziness of biological patterns. The means by which living things encode information is a problem common to both neural biology and the regulation of gene expression by the genome. Physical analogies are employed to highlight some of the problems and opportunities in this area.
Staying with the ingroup or outgroup? A cross-country examination of international travelers’ home-sharing preferences

Abstract This paper examines the joint effect of host’s cultural identity (i.e., ingroup vs. outgroup), presence of a travel companion, and consumer’s country of origin on international travelers’ evaluations of home-sharing services. A quasi-experimental design was implemented to collect data from U.S. and Chinese consumers. Results indicate a significant three-way interaction: In a culturally different destination, Chinese consumers prefer home-sharing services provided by ingroup hosts whether traveling alone or with a companion, whereas American consumers only show ingroup preference if they travel alone; when traveling internationally with a travel companion, American consumers prefer home-sharing services provided by an outgroup host. Further, psychological closeness and perceived experience authenticity are found to be the mediators underlying international travelers’ home-sharing preferences. Findings of this study offer new insights to the research and management of sharing economy.
Structural evolution of directionally freeze-cast iron foams during oxidation/reduction cycles

Abstract Cyclical oxidation/reduction behavior of iron-based powders and porous pellets is of great interest for iron-air batteries, steam-iron, and chemical looping processes, but extended cycling is limited by degradation via sintering or pulverization. To address these problems, we use directional freeze casting to fabricate porous iron foams, consisting of colonies of parallel iron lamellae and open channels of sufficient width (20–40 and 20–50 μm, respectively) to accommodate iron/iron oxide volume changes during redox cycling. Iron foams of three different initial channel porosities (48, 61 and 65 vol.%) are fabricated via water-based freeze casting of Fe2O3 powders followed by reduction with H2 and sintering. The evolution of these iron foams is examined after 5 and 10 redox cycles between Fe3O4 and Fe at 800 °C (via steam and H2) using optical microscopy, scanning electron microscopy, and synchrotron X-ray tomography. Redox cycling causes a macroscopic foam shrinkage as the iron lamellae grow closer together, decreasing (and even sometimes eliminating) the channel width between lamellae. Smaller micropores within individual iron lamellae are partially preserved, consistent with new porosity formation via vacancy diffusion and clustering in the oxide phase. Additionally, a dense Fe shell forms on the exterior surface of most samples, caused by lamellae contacting and sintering during oxidation, followed by formation of an impermeable Fe layer during reduction. Strategies are proposed to reduce both channel constriction and shell formation, which are undesirable as they restrict gas phase transport.
A Probabilistic Synapse With Strained MTJs for Spiking Neural Networks

Spiking neural networks (SNNs) are of interest for applications for which conventional computing suffers from the nearly insurmountable memory–processor bottleneck. This paper presents a stochastic SNN architecture that is based on specialized logic-in-memory synaptic units to create a unique processing system that offers massively parallel processing power. Our proposed synaptic unit consists of strained magnetic tunnel junction (MTJ) devices and transistors. MTJs in our synapse are dual purpose, used as both random bit generators and as general-purpose memory. Our neurons are modeled as integrate-and-fire components with thresholding and refraction. Our circuit is implemented using CMOS 28-nm technology that is compatible with the MTJ technology. Our design shows that the required area for the proposed synapse is only $3.64~\mu \text {m}^{2}/\text {unit}$ . When idle, the synapse consumes 675 pW. When firing, the energy required to propagate a spike is 8.87 fJ. We then demonstrate an SNN that learns (without supervision) and classifies handwritten digits of the MNIST database. Simulation results show that our network presents high classification efficiency even in the presence of fabrication variability.
Evaluating the Effects of a Brief Tobacco Intervention in the US Air Force.

Introduction Military personnel have among the highest rates of tobacco use in the United States. Unfortunately, there are few interventions aimed at reducing tobacco use among this vulnerable population. The current study addresses this need by evaluating the short-term effectiveness of a Brief Tobacco Intervention (BTI), a 40-min group-based intervention designed to reduce contemporary patterns of tobacco use among a sample of US military enlistees during an 11-week period of involuntary tobacco abstinence. Aims and methods Participants were 2999 US Air Force Technical Trainees at Joint Base San Antonio-Lackland Air Force Base in San Antonio, Texas from April 2017 through January 2018. Participants were cluster randomized to three conditions: (1) BTI + Airman's Guide to Remaining Tobacco Free (AG), (2) AG intervention, or (3) standard smoking cessation intervention. The primary analysis was a comparison of the interventions' efficacies in preventing tobacco use during Technical Training, conducted using a generalized estimating equations logistic regression model controlling for covariates. Multiple imputation was used to account for loss to follow-up. Results There was not a significant difference by condition in the use of tobacco products at follow-up (p = .454). The BTI + AG condition did produce short-term changes in perceived harm, intentions to use tobacco, knowledge about tobacco products, and normative beliefs. Conclusions These findings suggest that while the intervention was effective in the short term, it was not potent enough over a 12-week period to prevent Airmen from initiating tobacco use. Future studies should examine whether adding a booster session or media campaign enhances the effectiveness of the intervention. Implications Despite the fact that most Airmen believe they will remain tobacco free following the ban in Technical Training, a large percentage of these Airmen resume and initiate tobacco use during this high-risk period. As a result, there is a need for interventions targeting the range of tobacco available to military trainees during a teachable moment when they report intentions to remain tobacco free. The current study shows that a BTI has promise in reducing long-term tobacco use, when coupled with additional interventions, such as a booster session or a media campaign.
Chapter 3 – Functional Groups

This chapter will serve as a review of the various functional groups that are commonly found in drug molecules. In the first section, the names and structures of four subsets of functional groups are discussed including those containing a carbonyl group, those in which nitrogen is central to the group; a series of sulfur-containing groups, and finally a selection of several miscellaneous functional groups. The concept of tautomerization is introduced with enols and then expanded to include several other functional groups that exist in tautomeric equilibrium. The second portion of this chapter is concerned with the electronic effects of functional groups. These effects are broken down into inductive and field effects, which are then grouped together as polar effects, and resonance. Several functional groups that are known to be electron withdrawing are then discussed followed by those that donate electrons. A brief discussion of alkyl groups as electron donators focuses on the concept of hyperconjugation.
Non Equivalence of Glutamic and δ-Aminolevulinic Acids as Substrates for Protochlorophyllide and Chlorophyll Biosynthesis in Darkness

It is presently assumed that in higher plants, chlorophyll (Chl) biosynthesis takes place only in the light (1). It is also widely held that this process originates in glutamic acid which is converted to tetrapyrroles via δ-aminolevulinic acid (ALA) by the plastids (2–5). As a consequence, it is firmly believed that glutamate and ALA are equivalent precursors of Chl In the present investigation (a) we confirm that in greening barley, Chlbiosynthesis can take place in darkness and (b) demonstrate that exogenous glutamate and exogenous ALA are not equivalent precursors of monovinyl (MV) and divinyl (DV) protochlorophyllide (Pchlide) and of Chlin darkness.
Yin Yang 1 is a potent activator of human T lymphotropic virus type 1 LTR-driven gene expression via RNA binding

Yin Yang 1 (YY1) is a DNA-binding transcription factor that either activates or represses gene expression. YY1 has previously been implicated in the transcriptional silencing of many retroviruses by binding to DNA sequences in the U3 region of the viral long terminal repeat (LTR). We here show that YY1 overexpression leads to profound activation, rather than repression, of human T lymphotropic virus type 1 (HTLV-1) expression, while YY1 down-regulation reduces HTLV-1 expression. The YY1 responsive element mapped not to YY1 DNA-binding sites in the HTLV-1 LTR but to the R region. The HTLV-1 R sequence alone is sufficient to provide YY1 responsiveness to a nonresponsive promoter, but only in the sense orientation and only when included as part of the mRNA. YY1 binds to the R region of HTLV-1 RNA in vitro and in vivo, leading to increased transcription initiation and elongation. The findings indicate that YY1 is a potent transactivator of HTLV-1 gene expression acting via binding viral RNA, rather than DNA.
Autonomous oscillations, bifurcations, and chaotic response of moored vessels

A single-point mooring (SPM) system consists of a surface vessel moored to a mooring terminal through a single line. A detailed study of the slow motions of an SPM system in response to time-independent external excitation is performed in this work and is an important part of the dynamic analysis of the system. A typical asymptotic response of a mooring system may be a time-independent position or large-amplitude low-period oscillatory motions in the horizontal plane. In the former case, the mooring line exhibits relatively low tensions. In the latter, high and potentially dangerous mooring line tensions are introduced. In this study, the system-oriented approach is adopted. Following the introduction, the mathematical model used for prediction of the slow motions of the moored vessel, and for explanation of its asymptotic response by stability analysis, is summarized in Section 2. In sections 3 and 4, bifurcation analysis of SPM systems in terms of easily changeable parameters during operations is performed. Finally, in Section 5, highly undesirable moorings system response modes are identified and studied. The results and conclusions of these sections are confirmed throughout the paper by numerical simulation of various SPM systems of different configuration and dynamic behavior.
Survey of US Living Kidney Donation and Transplantation Practices in the COVID-19 Era

Introduction: The scope of the impact of the COVID-19 pandemic on living donor kidney transplantation (LDKT) practices is not well defined. Methods: We surveyed U.S. transplant programs to assess practices, strategies and barriers to living LDKT during the COVID-19 pandemic. After IRB approval, the survey was distributed 5/9/20-5/30/20 by email and postings to professional society list-servs. Responses were stratified based on state COVID-19 cumulative incidence levels. Results: Staff at 118 unique centers responded, representing 61% of U.S. living donor recovery programs and 75% of LKDT volume in the pre-pandemic year. Overall, 66% reported LDKT surgery was on hold (81% in "high" vs. 49% in "low" COVID-19 cumulative incidence states). Thirty-six percent reported that evaluation of new donor candidates had paused, 27% reported evaluations were very decreased (>0% to <25% typical) and 23% reported evaluations were moderately decreased (25% to <50% typical). Barriers to LDKT surgery included program concerns for donor (85%) and recipient (75%) safety, patients concerns (56%), elective case restrictions (47%) and hospital administrative restrictions (48%). Programs with higher local COVID-19 cumulative incidence reported more barriers related to staff and resource diversion. Most centers continuing donor evaluations used remote strategies (video 82%; telephone 43%). As LDKT resumes, all programs will screen for COVID-19, although timeframe and modalities vary. Recommendations for pre-surgical self-quarantine are also variable. Conclusion: The COVID-19 pandemic has had broad impacts on LDKT practice. Ongoing research and consensus-building are needed to reduce barriers, guide optimal practices, and support safe restoration of LDKT across centers.
Exploring Mesoscale Contact Mechanics by Atomic Force Microscopy

Mesoscale contact junctions, formed by mechanical interaction of elastic, viscoelastic, and elastoplastic solids, play a crucial role in a wide range of physical phenomena, going from rubber friction and adhesion to biological adhesion in filamentary attachment pads and cell adhesion and interaction with physical scaffolds. Moreover, they affect the response of several microelectromechanical systems and impact the performance of novel lithographies that manipulate objects, pattern surfaces, and transfer molecules with nanoscale accuracy. It is well known that the behavior of contact spots is highly complex since it depends on different factors, namely, contact geometry, bulk and surface (visco)elasticity, plasticity, physical and chemical adhesion. The introduction of novel experimental strategies, aimed to tightly correlate the junction response with their relevant interfacial properties, is certainly mandatory and highly promising. In this chapter, we present atomic force microscopy as an ideal tool for contact mechanics investigations on individual and multiple contact junctions. In particular, we focus on the fabrication of custom probes, with characteristic size from a few hundred nanometers to several microns, and on their use in nanoindentation studies. We also discuss paradigmatic experiments addressing the role of interfacial roughness, viscoelasticity, plasticity, and adhesion on the mechanical response of mesoscale contacts.
Preparation of High Tc Superconducting Compound by Laser Ablation

High Tc superconducting YBCO compounds have been prepared by Ar-F excimer laser ablation on SrTiO3 and on metal substrates. Critical temperature (Tc) of the specimen formed on SrTiO3 (100) substrate was 88K and critical current densities (Jc) at 77K over 2 mm x 2 mm squared area at 0.5, 1.0 and 8.0T were 2.3 x 104, 1.5 x 104 and 2.0 x 103 A/cm2, respectively. YBCO on the metal substrate, Hastelloy C-276 with SrTiO3 thin buffer layer prepared by this method showed high Tc of 83K and Jc of 500 A/cm2 at 77K, 0T. The excellent Jc vs. magnetic field property is attractive for the application of the compound as practical conductors.
Microsporidia in Higher Vertebrates

Encephalitozoon cuniculi was first reported in rabbits and laboratory rodents in the early 1920s, and this species remains the most frequently observed organism in nonhuman vertebrates. Serological surveys reported prevalence rates as high as 80% in hamsters, 30% in rats, and 85% in guinea pigs. This chapter describes microsporidial infections in a variety of domestic mammalian hosts such as mice, rats, guinea pigs and hamsters, and wild mammalian hosts such as rodents and rabbits. It discusses a few cases of naturally occurring microsporidiosis that have been reported in nonhuman primates. The chapter also talks about microsporidial infections in dometic animal hosts and wild carnivores. Until recently, the species of microsporidia in avian tissues had not been determined, and no parasite species had been categorized as an avian pathogen. Only a few cases of naturally occurring microsporidiosis, including several different parasite genera, are reported in amphibian or reptile hosts.
A natural language tutorial dialogue system for physics

Abstract : We describe the WHY2-ATLAS intelligent tutoring system for qualitative physics that interacts with students via natural language dialogue. We focus on the issue of analyzing and responding to multi-sentential explanations. We explore approaches for achieving a deeper understanding of these explanations and dialogue management approaches and strategies for providing appropriate feedback on them.
Some generalizations of correspondence analysis

Abstract Correspondence analysis of a bivariate table has many different optimality properties. For instance, the scores computed by correspondence analysis linearize both regressions, and maximize the correlation coefficient. We try to generalize both properties to the multivariate situation, using the concept of maximizing any aspect of the correlation matrix, and the concept of simultaneously linearizing all bivariate regressions.
E. coli-expressed human neurotrophin-3 characterization of a C-terminal extended product

Publisher Summary In the development of proteins as therapeutic agents, it is crucial to ensure the homogeneity of the potential products; however, over-expression of recombinant proteins in E.coli often leads to translational errors as well as post-translational modifications. This chapter describes the E.coli expression of human neurotrophin-3 (NT-3), a member of the nerve growth factor (NGF) family of neurotrophic factors, and discusses the characterization of this higher molecular weight product, and shows that it is due to misreading through the UGA codon by tryptophan incorporation. The chapter shows that when the cloned DNA is terminated with the codon UGA, both the mature protein and a higher molecular form are produced in the inclusion bodies. Examination of the endoproteinase Lys-C map of the higher molecular weight material demonstrates that the peptides corresponding to the C-terminus are absent and a new peptide is generated. N-terminal analysis of the peptide gives IGRTWGSADK. Therefore, the C-terminus of the protein has been extended with the peptide WGSADK. This sequence matches perfectly with the translated cloned DNA sequence, before another in-frame termination codon (UAA) is met. The chapter explains that the higher molecular weight form of NT-3 is caused by reading through of the UGA stop codon by tryptophan incorporation.
Sub-nanosecond electrical pulses for medical therapies and imaging

Nanosecond electrical pulses have been successfully used to treat subcutaneous tumors with needle arrays as pulse delivery systems. Reducing the pulse duration into the subnanosecond range enables driving wideband radiation sources, which can deliver high electric fields deep into the body. This electromagnetic energy may be used to stimulate bioelectric effects, such as electrical activation of platelets for hemostasis or electric field induced apoptosis of tumor cells. To this end we have investigated the biological response to sub-nanosecond pulsed electric fields. With the goal of ultimately delivering electric field exposures with an impulse radiating antenna (IRA), we have developed a 150-ps, 50-kV pulse generator and concurrently studied the radiation characteristics of the prolate-spheroidal antennas, when excited by such a pulse. In addition to applying using ultrashort electrical pulses for medical therapies, the use of Impulse Radiating Antennas in the hundred-picosecond temporal range lead us to medical imaging methods with sub-centimeter spatial resolution.
Competition among marine phytoplankton for different chelated iron species

Dissolved-iron availability plays a critical role in controlling phytoplankton growth in the oceans1,2. The dissolved iron is overwhelmingly (∼99%) bound to organic ligands with a very high affinity for iron3,4,5, but the origin, chemical identity and biological availability of this organically complexed Fe is largely unknown6. The release into sea water of complexes that strongly chelate iron could result from the inducible iron-uptake systems of prokaryotes (siderophore complexes)7,8,9 or by processes such as zooplankton-mediated degradation and release of intracellular material (porphyrin complexes). Here we compare the uptake of siderophore- and porphyrin-complexed 55Fe by phytoplankton, using both cultured organisms and natural assemblages. Eukaryotic phytoplankton efficiently assimilate porphyrin-complexed iron, but this iron source is relatively unavailable to prokaryotic picoplankton (cyanobacteria). In contrast, iron bound to a variety of siderophores is relatively more available to cyanobacteria than to eukaryotes, suggesting that the two plankton groups exhibit fundamentally different iron-uptake strategies. Prokaryotes utilize iron complexed to either endogenous7,8,9 or exogenous siderophores9, whereas eukaryotes may rely on a ferrireductase system10,11 that preferentially accesses iron chelated by tetradentate porphyrins, rather than by hexadentate siderophores. Competition between prokaryotes and eukaryotes for organically-bound iron may therefore depend on the chemical nature of available iron complexes, with consequences for ecological niche separation, plankton community size-structure and carbon export in low-iron waters.
Acetyl Coenzyme A Carboxylase: THE ROLES OF SYNTHESIS AND DEGRADATION IN REGULATION OF ENZYME LEVELS IN RAT LIVER

The roles of synthesis and degradation in the regulation of acetyl coenzyme A carboxylase levels in rat liver following fasting and fat-free feeding have been studied. Antibodies prepared to homogeneous chicken liver acetyl-CoA carboxylase were shown to cross-react with rat liver acetyl-CoA carboxylase. Enzyme from both species was totally inactivated as well as precipitated by this antibody preparation. Furthermore, quantitative precipitin curves and equivalence point determinations indicated that enzymes from the two species were precipitated in equal quantity by antibody and that the two enzymes had identical turnover numbers. It was also shown that disaggregated, aggregated, and palmityl-CoA-treated enzyme were all equally precipitated by antibody. Immunological analysis of crude homogenates of rat liver from animals treated with different diets, which had specific activities for acetyl-CoA carboxylase varying over 25-fold indicated that there was a constant amount of immunologically precipitable enzyme per unit of enzyme activity. The changes in acetyl-CoA carboxylase activity measured after dietary alteration result from changes in the enzyme content of liver rather than from activation or inhibition of preformed enzyme. The relative rates of acetyl-CoA carboxylase synthesis were determined by quantitative precipitation of the enzyme by antibody after pulse labeling with 3H-leucine. There was a 5- to 10-fold increase in the rate of enzyme synthesis after fat-free feeding of previously fasted rats. The rate of degradation of acetyl-CoA carboxylase in rats fed a fat-free diet was found to be first order with a t½ of approximately 48 hours, whereas in fasted rats a t½ of 18 hours was obtained. In rats fed a 12% fat diet the rate of acetyl-CoA carboxylase degradation was similar to that found in animals fed a fat-free diet, whereas the rate of synthesis was diminished, thus suggesting that independent factors regulate the rates of acetyl-CoA carboxylase synthesis and degradation in rat liver.
The Massive Close Binary in the δ Ori A Triple System

We present an analysis of short-wave, high-dispersion ultraviolet spectra of the triple star δ Ori A from the International Ultraviolet Explorer Satellite’s (IUE) Final Archive. These spectra were cross-correlated against AE Aur to find the components’ radial velocities, which were then used to produce the system’s orbital elements. The long-period tertiary star in the δ Ori A system was not seen in the resulting cross-correlation functions (CCFs). The close binary’s eclipses allow the orbit’s inclination to be estimated by modeling of its Hipparcos light curve. The primary star appears to have a mass of 11.2 M ⊙ and the secondary seems to have a mass of 5.6 M ⊙ , both of which are about 1/3 of the expected values for stars of their MK types. Although we expected the massive close binary in the δ Ori A system to be a pre-Roche lobe overflow (RLOF) system, these masses appear to require that it be a post-RLOF system. The full description of this work, including the tomographic separation of the spectra for the close binary’s components, appears in Harvin et al. (2002).
Body Mass Index in Adolescent Spinal Deformity: Comparison of Scheuermann's Kyphosis, Adolescent Idiopathic Scoliosis, and Normal Controls.

Abstract Study Design Prospective, multicenter study of Scheuermann's kyphosis (SK) and adolescent idiopathic scoliosis (AIS) compared to a control group. Objectives Compare body mass index (BMI) and Scoliosis Research Society Questionnaire–22 (SRS-22) scores among two diagnosis and one control group. Summary of Background Data BMI has been reported as increased in SK patients; however, there are few recent data on this subject or comparing SK to AIS. Methods Ninety-two SK patients (37 female, 55 male, average age 16 years), 1,051 AIS patients (814 female, 237 male, average age 15 years), and 380 adolescents without scoliosis (controls) were compared based on age, gender, race, height (m), weight (kg), BMI, and SRS-22 scores. An analysis of variance was used to test differences in BMI and SRS-22 scores between the groups and between males and females. Pearson correlations determined the relationship between AIS T5–T12 kyphosis and BMI, SK max kyphosis and BMI, and to determine the relationship between BMI and SRS-22 scores in each group. Results More SK patients were “obese” and “overweight” (28% and 22%) compared to the AIS (6% and 9%) and Control groups (5.8% and 17.9%) (p Conclusions SK patients are at increased risk for elevated BMI and worse SRS-22 scores, indicating that they may suffer from delayed diagnosis and increased surgical complications. AIS patients are at increased risk for issues related to low BMI and should also be monitored.
General purpose languages should be metalanguages

In his paper, The Next 700 Programming Languages, the late Landin writes that "most programming languages are partly a way of expressing things in terms of other things and partly a basic set of given things." Landin tries to separate the general purpose aspects of a language from the problem specific aspects. Instead of hundreds of languages with ad-hoc differences, Landin proposes one general-purpose language with many different sets of primitive operations for different problem domains.However, achieving this separation is not so easy: the domain specific parts cannot always be neatly packaged up in a set of primitives, but instead may require complex syntactic and semantics structures. In the last decade or so we made significant steps towards this vision through the development domain-specific embedded languages (DSELs). We discovered how to trick several general purpose languages into making software libraries look like domain-specific languages. As a result, we now develop DSELs that enjoy many of the benefits of a real languages: they perform domain-specific type checking, they provide custom syntactic abstractions, and they optimize themselves to achieve high efficiency. Most importantly, unlike real languages, DSELs nicely inter-operate with each other through the underlying general purpose language.The main limitation of today's DSELs is that they leak: the underlying general purpose language peeks through at inopportune times. This is not surprising; these general purpose languages were not designed to be metalanguages for building DSELs. In this talk I argue that general purpose languages should be designed to be metalanguages and I identify some features that could help our general purpose languages become metalanguages.
Intramolecular cyclizations leading to bridgehead bicyclics 2. 5,5‐dialkylhydantoin derivatives

The effect of substituenls in the 5-position on the course of hydantoin intramolecular alkylation reactions was studied. Dialkyl and diaryl substituted intermediates resulted in the same type product, 2,3-dihydro-6,6-disubstituted imidazo[2,1-b]oxazole-5(6H)ones, indicating alkylation on oxygen rather than nitrogen. The mass spectral and nmr characteristics of these bicyclic compounds are discussed.