cssi/SciSciGPT-SciSciNet huggingface dataset:
La obsolescencia no-programada: una circunnavegación alrededor del testimonio latinoamericano y sus avatares críticos

Resumen: Este articulo ofrece un panorama de las diversas formas narrativas que suelen agruparse bajo el rubro de testimonio latinoamericano. Una vez esbozadas las principales corrientes en los debates criticos generados por el testimonio, este articulo concluye con la sugerencia de que las futuras investigaciones han de enfocarse en la reevaluacion de los marcos metodologicos a la luz del contexto actual marcado por la globalizacion, digitalizacion y el vertiginoso cambio de las nociones de lo real y lo virtual. Palabras clave: testimonio latinoamericano, critica del testimonio. Abstract: This article offers an overview of the myriad narrative forms grouped under the label of Latin American testimonial discourse (testimonio). After outlining the main currents in the critical debates generated by testimonio, this article also offers some suggestions for further research by calling for an in-depth re-evaluation of existing methodological frameworks within the context of globalization, digitalization, and rapidly changing notions of the virtual and the real. Key words: Latin American testimonio, testimonio criticism.
THE IMPACT OF RACE ON ENVIRONMENTAL QUALITY: An Empirical and Theoretical Discussion

The toxic pollution problem is composed of several interre- lated parts which are involved in the process of production, use, and disposal of chemicals and products considered necessary for society. Each day, millions of pounds of toxic chemicals are used, stored, disposed of, and transported in and out of communities throughout the United States. Most Americans assume that pollution and other environmental hazards are problems faced equally by everyone in our society. But a growing body of research shows that the most common victims of environmental hazards and pollution are minorities and the poor. Disproportionate exposure to envi- ronmental hazards is part of the complex cycle of discrimination and depri- vationfaced by minorities in the United States. This article examines social science empirical research on the relationship between race, class, and the distribution of environmental hazards and the theoretical perspectives which have emerged to explain environmental inequities. The article also discusses the link between the environmental justice movement, which seeks to confront the causes and consequences of environmental inequities, and social science research on environmental inequity.
Development and Psychometric Testing of the Criterion-Referenced Measurement Tool for Genetics.

BACKGROUND AND PURPOSE The purpose of this study was to develop a criterion-referenced instrument to provide effective documentation of knowledge of advanced practice nursing in genetics. METHODS This is a methodological psychometric study. RESULTS The Criterion-Referenced Measurement Tool for Genetics (CRMTG) was found to be valid with a content validity index of .88 and reliable with a Cronbach's alpha of .99 based on the findings of this study. The CRMTG pass rates indicated a significant difference between nurses who practice in a genetic setting and nurses who do not practice in a genetic setting (p < .001). CONCLUSIONS The CRMTG was found to be a valid and reliable instrument to provide effective documentation of knowledge of advanced practice nursing in genetics.
Disciplinary Literacies in an Engineering Club: Exploring Productive Communication and the Engineering Design Process

This conceptual article addresses the question: What are the disciplinary literacy practices surrounding the Engineering Design Process (EDP) at the elementary level? Recent attention has focused o...
Thrombolytic Therapy for Lower Extremity Deep Vein Trombosis

This section provides a comprehensive procedural report for thrombolytic therapy for lower extremity deep vein thrombosis procedure with up-to-date explanatory notes, synopsis of the indications and contraindications and potential complications in an organized and practical format.
A Distinctly American Opportunity: Exploring Non-Standardized English(es) in Literacy Policy and Practice

National policies on language and literacy curricula reinforce standardized language approaches. These not only fail to meet the needs of non-standardized English speakers but also place our monoli...
Do Federal Regulations Have an Impact on Kidney Transplant Outcomes

Transplantation is one of the most highly regulated fields in health care. An important component of transplant oversight is the performance assessment of transplant centers as measured by 1-year patient and graft survival outcomes. The use of the Organ Procurement and Transplantation Network and Scientific Registry of Transplant Recipients flagging mechanism for quality improvement as criteria for Center for Medicare and Medicaid Services certification has resulted in greater importance in transplant program operations. Although supporters of this program of encouraging Quality Assurance and Performance Improvement point to improved survival outcomes for more than the decade, others assert that the oversight is unnecessarily punitive, results in tremendous resource utilization, and discourages innovation. Data exist to support an inhibitory effect on national transplant volume. Although survival outcomes are risk adjusted, limitations on national data collection prevent several important risks from being incorporated into the models. This has led to the consensus that many transplant centers have become increasingly risk averse in this environment, which may indirectly reduce access to transplant for candidates who could still benefit from transplantation. Recently enacted modifications to performance evaluation by Center for Medicare and Medicaid Services and the Organ Procurement and Transplantation Network appear to acknowledge these concerns and have the potential to recalibrate transplant center focus away from first-year outcomes and more toward expanding transplant volume, innovation, and overall improvements in care.
Optical Antenna Spontaneous Emission; How Much Faster Than Stimulated Emission?

With optical antennas, spontaneous light emission becomes faster than stimulated emission, but the enhancement is limited by optical losses through the “anomalous skin effect”. Maintaining 50% efficiency, a 10× speedup beyond stimulated emission should be possible.
The Formalization of a Biological Safety Program at the National Institute of Standards and Technology

In recent years, research efforts and measurement capabilities in biological science have significantly increased at the National Institute of Standards and Technology (NIST). Biological experiments are often performed by NIST physicists, chemists, and engineers who are not traditionally trained in biological safety protocols. A biosafety working group comprised of research scientists from across NIST was formed to address the need for an expanded, formalized biosafety program to ensure proper training and protocols for all biological experiments performed within the organization. With the support of NIST management, a dedicated Biosafety Officer was hired to formalize the biological safety program, and new requirements were established for training of staff and visiting scientists, registration of biohazardous materials, inspection of biological laboratories, and audits of the program to ensure continued compliance with internal biosafety requirements and other relevant biosafety regulations and guidelines.
Oncologist preferences in advanced soft tissue sarcoma: A discrete choice experiment.

147Background: Soft-tissue sarcomas (STS), a rare heterogeneous group of cancers originating in the muscle, fat, blood vessels or other fibrous/connective tissues, account for 1% of all cancers dia...
The Environmental Services Perspective on Hospital Room Design: A Mixed-Methods Approach

Our aim is to enhance the safety and efficiency of all healthcare staff by designing patient rooms that meet the physical and cognitive needs of those providing direct and indirect patient care in ...
Chapter 20 Role of Ions and Intracellular Proteins in Exocytosis

Publisher Summary This chapter describes a new protein called synexin that induces Ca 2+ -dependent formation of pentalaminar complexes among secretory granule membranes. Synexin has proved distinct from other more conventional candidates for Ca 2+ -effect mediators, such as calmodulin, actomyosin, and tubulin. The chapter also describes the process of membrane breakage or fission that finally results in the release of secretory vesicle contents. Studies comparing the granule lysis reaction with predicted behavior of secreting chromaffin and other cells are briefly reviewed in the chapter. The biochemical data supporting the exocytosis hypothesis are that the storage organelles from different cells can be isolated and therefore shown to be discrete objects and when secretion occurs, the entire organelle contents ranging from small molecules to large proteins can be found in the extracellular medium. Calcium plays a critical role in regulating exocytosis in a number of systems.
Recovery Services and Outcomes in a State Psychiatric Hospital

Recovery has emerged as a focus of mental health rehabilitation in the past decade. Many have suggested that various domains of recovery-orientated services are integrated to an efficacious mental health care system. In this study we examined the association of domains of recovery-oriented services with recovery outcomes among inpatients in a state psychiatric hospital. A convenience sample of 36 hospital patients participated in a survey that included two standardized scales, with one measuring 6 domains of recovery-orientation of hospital-based services and one measuring 5 aspects of patients’ recovery outcomes. We used regression analysis to estimate the association between recovery-oriented services and recovery outcomes adjusting for gender, race, and education. Nearly 90% of patients had lengths of stay of more than 3 months. On average, patients reported receiving moderate levels of recovery-oriented services. Nevertheless those who reported receiving higher levels of recovery-oriented services also reported better recovery outcomes. Specifically three domains of recovery-oriented services, i.e., life goal vs. symptom management, individual tailored, and diversity of treatment options, are associated with better overall recovery and 3 specific aspects of recovery, namely willingness to ask for help, goal and success orientation, and reliance on others. The data from a small sample of patients at a state psychiatric hospital suggest that self-reported recovery-oriented services received are associated with better recovery outcomes. Future larger studies are warranted to confirm the study findings, and to examine whether a contemporary recovery-focused care model can facilitate even greater recovery outcomes.
Dietary aspects of developmental orthopedic disease in young horses.

Nutrition offers a practical opportunity to intervene in several skeletal conditions that involve conversion of cartilage to bone, known collectively as developmental orthopedic disease. Many causative factors have been implicated, but none has yet been shown to be necessary or sufficient to determine the cause of developmental orthopedic disease. Thus, veterinarians should be cautious about dietary recommendations intended to prevent or correct these conditions. This article discusses critically various recommendations, such as supplementation of copper and other trace minerals and specific restriction of protein and soluble carbohydrate.
Condition of the Mid-Atlantic Estuaries: Production of a State of the Environment Report

The U.S. Environmental Protection Agency has released a report entitled Condition of the Mid-Atlantic Estuaries. That report summarizes the findings of several studies conducted by federal and state agencies and academic institutions in Chesapeake Bay, Delaware Estuary, and the coastal bays of Delaware, Maryland, and Virginia, and simultaneously addresses two distinct audiences: environmental managers and the general public. This paper documents the process of preparing the Estuaries Report, emphasizing the lessons learned in merging information from a wide-variety of sources and in reporting the results to multiple audiences. The major difficulties in preparing the report included: 1) choosing a format and topics that adequately addressed both environmental managers and the public, 2) resolving spatial and temporal disparities in the assembled data sets, and 3) establishing threshold values that distinguished between acceptable and unacceptable conditions in indicators. Our solutions to these challenges and alternatives are discussed. We conclude that a small team of knowledgeable scientists can effectively merge the information of diverse sources into a document that is useful to both environmental managers and the interested public. However, considerable interaction between the team and other scientists was necessary to resolve ambiguities and assure relevancy and accuracy. These findings support the proposition that the vast sources of existing environmental information can be easily and effectively used to assess the ecological condition across large regions.
Another Look at Least Common Multiple and Greatest Common Factor

Most contemporary middle school mathematics programs use the notion of prime factorization to obtain the least common multiple and the greatest common factor of a pair of natural or whole numbers. Success in determining the least common multiple or greatest common factor for a pair of numbers then depends on the ability to obtain the prime factorization for any given number. The main disadvantage of this approach arises when either of the pair of numbers is quite large. For example, determining the least common multiple of 2464 and 7469 by prime factorization involves knowledge of divisibility tests for primes and of the primes themselves. The purpose of this paper is to examine another method for obtaining the least common multiple and greatest common factor of a pair of numbers without using prime factorization. These methods provide opportunities for students to make and test conjectures about the possible generalizations of the results to more than two numbers. Such conjecturing should aid students in developing problem-solving skills. It is not at all difficult for middle school children to convince themselves that if two natural numbers have 1 as
Grow Your Own Professional Development: Faculty Self-Study

Teaching begins with you. The power of your personal narrative to define the parameters of your own classroom inquiry is at the forefront of your academic and professional development. This does not mean that there should be no outside accountability. It does, however, bring to mind that change that is demanded by others is less powerful, less meaningful, and less sustainable than change that is self-initiated and self-motivated. You are a generator of knowledge who can learn about your teaching and its impact on studentsâ€™ learning by studying your own classroom. For the last decade, I have been practicing what is called self-study teacher research which applies to all practitioners who are interested in studying and improving their practice with colleagues. Self-study is a methodology to critically examine oneâ€™s own practitioner-based practice as a way of developing a more consciously driven mode of professional activity (Samaras, 2002); that is you are examining your own teaching from the inside and sharing it with others outside of your classroom for alternative perspectives as you grow your own professional development. Ann Lieberman and Desiree Pointer Mace in their article, Making Practice Public: Teaching Learning in the 21st Century, [2010, Journal of Teacher Education, 61 (1-2), 77-88], call for a â€œlocal teachingâ€ movement where â€œGrowing your own professional developmentâ€ means giving value to your efforts to shape teaching and learning in your classroom; â€œJust as a local-foods gardener is invested in the daily care to grow food that will grace the tables of his or her community, teachers can assess a greater investment in their own knowledge and expertise by sharing their fruits of their labors with each otherâ€ (p. 86). The key is to belong to a learning community in practice which is essential to your professional practice and the scholarship of teaching at the university. Come learn about the steps involved in getting you started in self-studyship.
ACUTE RIGHT VENTRICULAR FAILURE FOLLOWING ATTEMPTED PATENT FORAMEN OVALE CLOSURE IN A PATIENT WITH REFRACTORY HYPOXEMIA ON VENOVENOUS EXTRACORPOREAL MEMBRANE OXYGENATION

Patent foramen ovale (PFO) is prevalent and can have hemodynamic consequences in respiratory failure requiring venovenous extracorporeal membrane oxygenation (VV ECMO). A 42 year old male with HIV-associated pulmonary arterial hypertension was admitted for Acute Respiratory Distress Syndrome
The complex response of free and bound amino acids to water stress during the seed setting stage in Arabidopsis

Free amino acids (FAAs) and protein-bound amino acids (PBAAs) in seeds play an important role in seed desiccation, longevity, and germination. However, the effect that water stress has on these two functional pools, especially when imposed during the crucial seed setting stage is unclear. To better understand these effects, we exposed Arabidopsis plants at the seed setting stage to a range of water limitation and water deprivation conditions and then evaluated physiological, metabolic, and proteomic parameters, with special focus on FAAs and PBAAs. We found that in response to severe water limitation, seed yield decreased, while seed weight, FAA, and PBAA content per seed increased. Nevertheless, the composition of FAAs and PBAAs remained unaltered. In response to severe water deprivation, however, both seed yield and weight were reduced. In addition, major alterations were observed in both FAA and proteome compositions, which indicated that both osmotic adjustment and proteomic reprogramming occurred in these naturally desiccation-tolerant organs. However, despite the major proteomic alteration, the PBAA composition did not change, suggesting that the proteomic reprogramming was followed by a proteomic rebalancing. Proteomic rebalancing has not been observed previously in response to stress, but its occurrence under stress strongly suggests its natural function. Together, our data show that the dry seed PBAA composition plays a key role in seed fitness and therefore is rigorously maintained even under severe water stress, while the FAA composition is more plastic and adaptable to changing environments, and that both functional pools are distinctly regulated.
Recessions and recoveries: Multinational banks in the business cycle

Abstract How does the expansion of multinational banks influence the business cycle of host countries? We study an economy where multinational banks can transfer liquidity across borders through internal capital markets but are hindered in their allocation of liquidity by limited knowledge of local firms’ assets. We find that, following domestic banking shocks, multinational banks moderate the depth of the contraction but slow down the recovery. A calibration to Polish data suggests that multinational banks reduce the average depth of recessions by about 5% but increase their duration by 10%. The predictions are broadly consistent with evidence from a large panel of countries.
Novel approach to model microstructure of dust-deposits comprised of polydisperse particles of arbitrary shapes

Abstract Morphology of airborne particles plays a key role in the growth rate of dust-cake formed on an exposed solid surface, or on the face of an air filter. The work presented in this paper reports on a fast and flexible algorithm to simulate the microstructure of dust-cakes resulting from deposition of non-inertial airborne particles of arbitrary shapes. Our approach is based on representing a non-spherical particle as an assembly of spherical beads connected to one another via springs and dampers. This mass-spring-damper (MSD) model allows one to study the effects of particle shape, particle size, and particle rigidity on the thickness and porosity of the dust-cakes that result from deposition of such aerosol particles in different applications. In aerosol filtration applications for instance, the ability to predict the thickness and porosity of a dust-cake comprised of non-spherical particles is needed before one can predict the pressure drop or collection efficiency of a dust-loaded filter. For demonstration purposes in this paper, dust-cakes comprised of particles with cubical and spherocylindrical shapes as well as Jacks-toy and Plus-sign shapes are simulated and discussed.
Exchange splitting and exchange-induced nonreciprocal photonic behavior of graphene in Cr I 3 -graphene van der Waals heterostructures

The exchange splitting and resulting electromagnetic response of graphene in a monolayer chromium triiodide ($\mathrm{Cr}{\mathrm{I}}_{3}$)--graphene van der Waals heterostructure are considered using a combination of density-functional theory and electromagnetic calculations. Although the effective exchange fields are in the hundreds of Tesla, for the equilibrium separation nonreciprocal effects are found to be weak compared to those for a comparable external magnetic bias. For nonequilibrium separations, nonreciprocal effects can be substantial.
OP0091 Differences in disease expression in adjuvant arthritis of lewis rats induced by mycobacteria or lipoidal amine

Background Marked polyarthritis is induced in male Lewis rats by injection of either heat-killed Mycobacterium tuberculosis in mineral oil (AdA) or lipoidal amine in complete Freund’s adjuvant (LA/CFA). For both models, paw swelling and body weight loss occur in all rats by 10 to 12 days after immunisation. Objectives Interestingly, however, the present study demonstrates that the morphologic and densitometric changes of AdA and LA/CFA are distinguishable. Methods We induced AdA or LA/CFA in male Lewis rats (180 g) and evaluated both clinical (body and spleen weight, volume of the tibiotarsal [hock] joints) and morphologic changes (bone mineral density [BMD] by DEXA; histopathologic lesions in the hock and femorotibial [knee] joints). Readings were obtained at the day of onset (as determined by initial paw swelling) as well as 5, 10 and 25 days after onset. Results Paw swelling, loss of body weight, enhanced spleen weight were identical in AdA and LA/CFA. In contrast, hock inflammation score, hock erosion score and hock cartilage score were lower in LA/CFA, though not statistically significant from AdA. Lesions developed more slowly in LA/CFA than in AdA. However, hock BMD as well as knee inflammation and erosion scores found to be different (shown here at Onset + 5 days): Conclusion Inflammatory and skeletal changes for AdA and LA/CFA were similar by clinical and histopathologic measures 10 days after onset, while inflammation receded by Onset + 25 days in LA/CFA more than it did in AdA. These data indicate that bone densitometric and morphologic findings can distinguish these two models of adjuvant arthritis despite their similar clinical presentations. This finding may be relevant in screening novel therapeutic candidates as these models may define different potential efficacious effects of a compound.
HDAC1 regulates the chromatin landscape to establish transcriptional dependencies in chronic lymphocytic leukemia

Abstract HDAC1 is a key regulator of gene expression in cancer. We identified a critical role for HDAC1 in establishing the transcriptional dependencies essential for survival in chronic lymphocytic leukemia (CLL) by profiling HDAC1 with BRD4, H3K27Ac superenhancers, H4K9Ac, chromatin accessibility signatures, Pol2 measurements and expression signatures to generate a regulatory chromatin landscape. Superenhancers marked by high levels of acetylation and BRD4 paradoxically also recruited the highest levels of HDAC1. HDAC inhibition poisoned transcription at these loci to selectively disrupt B-cell transcription factors and B-cell receptor signaling. HDAC1 was also recruited genome-wide at promoters without superenhancers to repress expression; HDAC inhibition induces these genes which include key microRNA networks that reciprocally downregulate CLL specific survival and driver genes. Our work provides a compelling rationale for profiling HDAC1 across cancers to characterize its role in driving the transcriptional dysregulation that is a hallmark of most cancers and develop epigenetic therapeutic strategies. Significance Our work definitively establishes the composition of the regulatory chromatin that enables HDAC1 to function as an activator and repressor at distinct target genes within the same tumor to drive transcriptional dysregulation and allow the expression of B cell specific signaling and survival networks that are critical for survival.
Effects of environmental temperature and sample pre-straining on high cycle fatigue strength of WE43-T5 magnesium alloy

Abstract This work investigates the effects of test temperature and sample pre-straining on the high cycle fatigue behavior of a magnesium alloy, WE43. Fatigue strength is found to deteriorate with environmental temperature from room to 100℃. In contrast to the samples pre-strained in tension, fatigue strength improves for the samples pre-strained in compression. The peak improvements of over 2x is determined for the samples pre-compressed to 6% strain. Significantly, the alloy sufficiently pre-strained in compression begins to exhibit the endurance limit. The interesting characteristics of the alloy behavior in fatigue are rationalized in terms of the microstructural evolution and deformation mechanisms.
NEPA and National Trends in Federal Infrastructure Siting in the United States

The United States' National Environmental Policy Act (NEPA) requires federal agencies to use environmental impact assessment tools to aggregate scientific information, garner stakeholder input, and weigh alternatives for infrastructure siting and operations decisions.Thus, NEPA plays a sweeping role in federal infrastructure provisioning. Using a comprehensive dataset of Environmental Impact Statements (EISs) prepared under NEPA from 2013 to 2019, we use natural language processing to identify geographic locations and artificial neural networks to classify discussed environmental impacts. We then describe geographic, temporal, and environmental trends in federal infrastructure provisioning. Finally, we use Bayesian hierarchical regression to assess how socio‐economic and demographic covariates shape county‐level EIS counts. Numerous federal agencies are involved in EIS production, but three agencies author the majority of EISs. Total EISs issued annually have declined since the early 2000s. EISs are more frequent in urban coastal counties, but do not show clear distributive trends by income or race.
Comparative Effectiveness of Immune Checkpoint Inhibitors in Patients with Platinum Refractory Advanced Urothelial Carcinoma.

Purpose:Five programmed cell death protein 1 or its ligand (L1) inhibitors are approved for treatment of platinum refractory, locally advanced/unresectable or metastatic urothelial carcinoma. Howev...
Molecular machine learning with conformer ensembles.

Virtual screening can accelerate drug discovery by identifying promising candidates for experimental evaluation. Machine learning is a powerful method for screening, as it can learn complex structure-property relationships from experimental data and make rapid predictions over virtual libraries. Molecules inherently exist as a three-dimensional ensemble and their biological action typically occurs through supramolecular recognition. However, most deep learning approaches to molecular property prediction use a 2D graph representation as input, and in some cases a single 3D conformation. Here we investigate how the 3D information of multiple conformers, traditionally known as 4D information in the cheminformatics community, can improve molecular property prediction in deep learning models. We introduce multiple deep learning models that expand upon key architectures such as ChemProp and Schnet, adding elements such as multiple-conformer inputs and conformer attention. We then benchmark the performance trade-offs of these models on 2D, 3D and 4D representations in the prediction of drug activity using a large training set of geometrically resolved molecules. The new architectures perform significantly better than 2D models, but their performance is often just as strong with a single conformer as with many. We also find that 4D deep learning models learn interpretable attention weights for each conformer.
Abnormal Responses to Trigeminal Nerve Injury: Clinical Syndromes, Surgical Pathology, and Neural Mechanisms

SUMMARY Abnormal responses to trigeminal nerve injury may be expressed in a wide range of symptom types, peripheral and central pathoses, and alternative mechanisms of pathophysiology. It is clear that the treating surgeon must attempt to differentiate those sources of pathophysiology in order to plan treatment and predict success or failure.
Novel compound heterozygous variants of TBXAS1 presenting with Ghosal hematodiaphyseal dysplasia treated with steroids

Background Homozygous or compound heterozygous pathogenic variants in the thromboxane A synthase 1 (TBXAS1) gene are associated with Ghosal hematodiaphyseal dysplasia (GHDD) which is characterized by defective hematopoiesis and increased bone density of long bones. Methods Patients 1 and 2 are identical twins, who presented with red blood cell transfusion-dependent normocytic anemia and thrombocytopenia with bone marrow fibrosis and cortical bone thickening of long bones on plain radiograph. To clarify the etiology of their anemia and thrombocytopenia, whole blood was used for the DNA extraction and analyzed using next-generation sequencing (NGS) on an in-house bone marrow failure syndrome panel. Results The NGS results indicated that these two patients carried two heterozygous variants in TBXAS1, exon7, c.583_584del, p.Ala195Leufs*12, and exon12, c.1420G>T, p.Gly474Trp, which were inherited from their mother and father, respectively. Patients 1 and 2 have been on chronic oral steroids with normalization of hemoglobin and platelet count after steroid initiation. Patient 3 is their sister who has normal blood counts but also has the same variants in TBXAS1 as her brothers. Radiographs showed cortical bone thickening and she has not required any treatment or transfusion. Conclusion We report three Caucasian siblings from non-consanguineous parents with novel compound heterozygous variants of TBXAS1 presenting with the phenotypes of GHDD. These three cases illustrate the variable clinical expressivity of the GHDD from two-compound heterozygous pathogenic variants of TBXAS1.
From Kindness and Diversity to Justice and Action: White Parents’ Ethnic–Racial Socialization Goals:

Ethnic–racial socialization (ERS) is the collection of practices by which individuals learn about norms, values, and customs regarding ethnicity and race (Hughes et al., 2006). In contrast to resea...
Characterization of Nanometric Qdots by AFM and Optical Microscopy

Quantum dots (Qdots) are fluorescent nanocrystals with exceptional brightness, tunability, and photostability, and huge potential in biomedical imaging from single-particle tracking, to multicolor imaging of cell structures, to real-time in vivo imaging of whole organisms. We have undertaken a combined optical and atomic force microscopy (AFM) investigation to better understand Qdots. We have developed multimodal instrumentations around AFM platforms and total internal reflection fluorescent microscopy (TIRFM) and Raman microscopy with environmental control for simultaneous characterization of the nanoscopic structural features and optical properties of individual particles and biomedical samples. Our new instruments allow fuller observation of Qdots nanocrystal core, biocompatible coating, oligomerization states, and their optical behavior, as they interact with the environment. For example, fluorescent time traces show that the fraction of “on”-time varied from a few percent to over 80% among isolated Qdots. Our high resolution AFM topological maps and super-resolution (below the diffraction limit) TIRFM localization detection reveal a varying degree of Qdot dimerization and oligomerization on glass and mica substrates. We also demonstrate direct fluorescence spectral mapping using a newly customized and integrated Raman-AFM instrument. By understanding the relationships between their topological, mechanical, electrostatic profiles and their optical properties, Qdots can be ultimately improved toward more quantitative biomedical imaging applications.
Defining the intracellular localization pathways followed by lysosomal enzymes in Dictyostelium discoideum.

Publisher Summary This chapter describes the biochemical and genetic methods used to define both the intracellular pathways followed by lysosomal enzymes and the molecular nature of the “sorting” signals found on the proteins. Using biochemical methods, the lysosomal enzymes α-man and β-glu in Dictyostelium are synthesized as precursor polypeptides that are cotranslationally translocated into the lumen of the endoplasmic reticulum (ER) and N-glycosylated. The precursors move at different rates from the RER to the Golgi complex, where they are sulfated and sorted into two classes. One class, containing the majority of the precursor polypeptides, is directed to lysosomes where they are rapidly cleaved to mature forms of the enzymes. The other class of precursors is rapidly secreted from cells. The different intracellular transport rates for the α-man and β-glu precursors support the existence of a transport-mediating receptor. The genetic approach involved the isolation and characterization of mutants altered in the secretion, modification, processing, and/or localization of lysosomal enzymes. Through biochemical analysis of these mutants, one can identify and characterize the molecular components involved in the processing and transport of this group of enzymes.
Embracing, contesting and negotiating new languages: Young children's early socialization into foreign language learning

Abstract With early childhood foreign language programs on the rise worldwide, this study is guided by the question of what young participants are learning about language, linguistic diversity and language education itself through their initial experiences with foreign language learning. Our study analyzes young learners’ encounters with linguistic difference and diversity in seven U.S. pre-school classrooms in which children learned Chinese, Korean or Spanish twice a week from a “language partner”. Adopting a language socialization perspective and analyzing video-recorded classroom interactions through the lenses of language awareness and engagement with language/s, we are able to characterize these early encounters with FL learning based on the interactional patterns of embracing, contesting and negotiating languages we discerned in our data. We highlight interactions that involve explicit talk about language/s as particularly promising in thinking about pedagogy as well as program goals and structures.
/spl lambda/-calculi with decidable /spl cap/-type checking

The typed lambda calculus is extended to accommodate the type intersection operator /spl cap/ of Coppo (1980). The extensions, L/sub 2/ and L/sub 3/, capture the expressive power of the intersection operator with respect to typeable closed lambda expressions, but do not sacrifice decidability of type checking. Type checking algorithms for L/sub 2/ and L/sub 3/ are given. It is shown that, although decidable, type checking in the extensions is NP-hard. >
PM2.5 source apportionment: reconciling receptor models for U.S. nonurban and urban long-term networks.

ABSTRACT Chemical mass balance (CMB) and trajectory receptor models were applied to speciated particulate matter with aerodynamic diameter ≤2.5 μm (PM2.5) measurements from Speciation Trends Network (STN; part of the Chemical Speciation Network [CSN]) and Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring network across the state of Minnesota as part of the Minnesota PM2.5 Source Apportionment Study (MPSAS). CMB equations were solved by the Unmix, positive matrix factorization (PMF), and effective variance (EV) methods, giving collective source contribution and uncertainty estimates. Geological source profiles developed from local dust materials were either incorporated into the EV-CMB model or used to verify factors derived from Unmix and PMF. Common sources include soil dust, calcium (Ca)-rich dust, diesel and gasoline vehicle exhausts, biomass burning, secondary sulfate, and secondary nitrate. Secondary sulfate and nitrate aerosols dominate PM2.5 mass (50–69%). Mobile sources ...
Measurement of the radial matrix elements for the 6 s S 1 / 2 2 → 7 p P J 2 transitions in cesium

We report measurements of the electric dipole matrix elements of the $^{133}\mathrm{Cs}\phantom{\rule{0.16em}{0ex}}6s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}\ensuremath{\rightarrow}7p\phantom{\rule{0.16em}{0ex}}^{2}P_{1/2}$ and $6s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}\ensuremath{\rightarrow}7p\phantom{\rule{0.16em}{0ex}}^{2}P_{3/2}$ transitions. Each of these determinations is based on direct, precise comparisons of the absorption coefficients between two absorption lines. For the $\ensuremath{\langle}6s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}||r||7p\phantom{\rule{0.16em}{0ex}}^{2}P_{3/2}\ensuremath{\rangle}$ matrix element, we measure the ratio of the absorption coefficient on this line to that of the ${D}_{1}$ transition $6s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}\ensuremath{\rightarrow}6p\phantom{\rule{0.16em}{0ex}}^{2}P_{1/2}$. The matrix element of the ${D}_{1}$ line has been determined previously with high precision by many groups. For the $\ensuremath{\langle}6s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}||r||7p\phantom{\rule{0.16em}{0ex}}^{2}P_{1/2}\ensuremath{\rangle}$ matrix element, we measure the ratio of the absorption coefficient on this line to that of the $6s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}\ensuremath{\rightarrow}7p\phantom{\rule{0.16em}{0ex}}^{2}P_{3/2}$ transition. Our results for these matrix elements are $\ensuremath{\langle}6s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}||r||7p\phantom{\rule{0.16em}{0ex}}^{2}P_{3/2}\ensuremath{\rangle}=0.574\phantom{\rule{0.16em}{0ex}}17(57){a}_{0}$ and $\ensuremath{\langle}6s\phantom{\rule{0.16em}{0ex}}^{2}S_{1/2}||r||7p\phantom{\rule{0.16em}{0ex}}^{2}P_{1/2}\ensuremath{\rangle}=0.278\phantom{\rule{0.16em}{0ex}}10(45){a}_{0}$. These measurements have implications for the interpretation of parity nonconservation in atoms.
Stochastic Online Scheduling Revisited

We consider the problem of minimizing the total weighted completion time on identical parallel machines when jobs have stochastic processing times and may arrive over time. We give randomized as well as deterministic online and off-line algorithms that have the best known performance guarantees in either setting, deterministic and off-line or randomized and online. Our analysis is based on a novel linear programming relaxation for stochastic scheduling problems, which can be solved online.
Molecular dynamics out of equilibrium: mechanics and measurables

Molecular dynamics is fundamentally the integration of the equations of motion over a representation of an atomic and molecular system. The most rigorous choice for performing molecular dynamics entails the use of quantum-mechanical equations of motion and a representation of the molecular system through all of its electrons and atoms. For most molecular problems involving at least hundreds of atoms, but generally many more, this is simply computationally prohibitive. Thus the art of molecular dynamics lies in choosing the representation and the appropriate equations of motion capable of addressing the requisite measurables. When used adroitly, it can provide both equilibrium (averaged) and time-dependent properties of a molecular system. Many computational packages now exist that perform molecular dynamics simulations. They generally include force fields to represent the interactions between atoms and molecules (smoothing out electrons through the Born-Oppenheimer approximation) and integrate the remaining particles classically. Despite these simplifications, all-atom molecular dynamics remains computationally inaccessible if one includes the number of atoms required to simulate mesoscopic solvents. Here we use analytical models to demonstrate how molecular dynamics can be used to limit the solvent size in systems experiencing either equilibrium or nonequilibrium conditions. It is equally important to address the measurables (such as reaction rates) that are to be obtained prior to the generation of the data-intensive trajectories. WIREs Comput Mol Sci 2014, 4:541–561. doi: 10.1002/wcms.1190 For further resources related to this article, please visit the WIREs website. Conflict of interest: The authors have declared no conflicts of interest for this article.
Low profile lens and reflectarray design for MM waves

In this work, we present low profile lens and reflectarray design for millimeter wave. We use artificially engineered dielectric materials (Dial-a-Dielectric) for these designs. We present comparison results with legacy designs that show comparable or better performance. We compare results of a flat lens using commercial off-the-shelf (COTS) materials, as opposed to metamaterials that are often required in lens designs based on the Transformation Optics (TO) approach. While lens designs based on Ray Optics (RO) do not suffer from the above drawback, they still require dielectric materials that may not be available off-the-shelf.
Epidemiology and Management of Essential Tremor in Children

Essential tremor (ET) is a common, often familial, movement disorder characterized by tremor of the limbs, head, and voice. Epidemiological surveys indicate that up to 5% of the adult population has ET, and 5–30% of adults with ET report symptom onset during childhood. There is, however, little published regarding ET in the pediatric population, and no prospective studies targeted specifically to children. Retrospective studies from subspecialty movement disorder clinics indicate that childhood-onset ET is usually hereditary, begins at a mean age of 6 years, and affects boys three times as often as girls. While ET occasionally results in disability during childhood, only one-quarter of children seeing a neurologist for ET require pharmacotherapy. Small case series suggest that propranolol is effective in approximately 50% of children with ET, but controlled treatment trials are lacking.
The antiviral drug ribavirin is a selective inhibitor of S -adenosyl -L -homocysteine hydrolase from Trypanosoma cruzi

Ribavirin (1,2,4-triazole-3-carboxamide riboside) is a well-known antiviral drug. Ribavirin has also been reported to inhibit human S-adenosyl-L-homocysteine hydrolase (Hs-SAHH), which catalyzes the conversion of S-adenosyl-L-homocysteine to adenosine and homocysteine. We now report that ribavirin, which is structurally similar to adenosine, produces time-dependent inactivation of Hs-SAHH and Trypanosoma cruzi SAHH (Tc-SAHH). Ribavirin binds to the adenosine-binding site of the two SAHHs and reduces the NAD(+) cofactor to NADH. The reversible binding step of ribavirin to Hs-SAHH and Tc-SAHH has similar K(I) values (266 and 194 microM), but the slow inactivation step is 5-fold faster with Tc-SAHH. Ribavirin may provide a structural lead for design of more selective inhibitors of Tc-SAHH as potential anti-parasitic drugs.
Design of a gradient-index beam shaping system via a genetic algorithm optimization method

Geometrical optics - the laws of reflection and refraction, ray tracing, conservation of energy within a bundle of rays, and the condition of constant optical path length - provides a foundation for design of laser beam shaping systems. This paper explores the use of machine learning techniques, concentrating on genetic algorithms, to design laser beam shaping systems using geometrical optics. Specifically, a three-element GRIN laser beam shaping system has been designed to expand and transform a Gaussian input beam profile into one with a uniform irradiance profile. Solution to this problem involves the constrained optimization of a merit function involving a mix of discrete and continuous parameters. The merit function involves terms that measure the deviation of the output beam diameter, divergence, and irradiance from target values. The continuous parameters include the distances between the lens elements, the thickness, and radii of the lens elements. The discrete parameters include the GRIN glass types from a manufacturer's database, the gradient direction of the GRIN elements (positive or negative), and the actual number of lens elements in the system (one to four).
On the control power of integer division

Abstract We consider the problem of simplifying the control structure of programs that manipulate numbers. In particular, we examine some simple programming language constructs which have sufficient computational power to eliminate all or most branching instructions (e.g. ‘while’, ‘if-then-else’ and ‘goto’ constructs) from such programs. We show that the operation of integer division by 2 is of considerable importance in this context. We also show that integer division by 2 cannot be computed by any loop-free program over the set of rational instructions, and hence that the power of integer division by 2 is, in a sense, greater than that of the conditional and unconditional branching instructions. We also investigate the power of indirect addressing in simplifying the control structure of programs over numerical inputs.
Multiple time scales in single input-single output high gain feedback systems

Abstract The asymptotic behaviour of single input-single output high gain feedback systems as the loop gain tends to infinity is investigated by singular perturbation methods. It is found that this class of feedback systems may have different time scales depending on system structure. A decomposition of the computation of the closed loop eigenvalues into two lower order problems is presented. An illustrative example is given.
Economic and Technical Determinants of Power System Development

This paper examines the major economic and technical determinants in the development of electric power systems. It first studies the fundamental motivations for centralization in the systems, i.e., increasing size of equipment and degree of interconnection. It then quantitatively analyzes the interrelationships among the average size of generating units, the degree of interconnection, and the level of system peak load. The analysis indicates that although the economic advantages of centralization have been much exploited in existing systems, additional benefits, particularly from scale economies of generating equipment may still be achieved. Moreover, for low load factor end users, such as residential customers, electricity production by small generators with low degrees of interconnection would not only be more expensive, but more capital-intensive than production by centralized systems.