cssi/SciSciGPT-SciSciNet huggingface dataset:
Open Surgical Reconstruction for Deep Venous Occlusion and Valvular Incompetence

This article considers the potential options for open deep venous reconstructions based on pathologic complication (obstruction vs insufficiency), anatomic location, presence of disease-free venous architecture, and patient need. Other things being equal, less invasive techniques and disease locations will be attempted as first-line therapy. When other options fail and symptoms persist, open venous surgery by means of bypass for obstructive disease and valve repair or replacement for deep venous insufficiency remains a viable option. The basic techniques available and overall success rates of each are considered.
“Coming Out of My Shell”: Motherleaders Contesting Fear, Vulnerability, and Despair through Family-focused Community Organizing:

Women’s political engagements often look different from those of men, and they are also undertheorized and understudied. The author examines how participation in family-focused community organizing...
Inferred Composition of Early Archaean Crust and Variation in Crustal Composition Through Tike

Abstract Two shields formed in late Proterozoio time (Llano uplift of Texas and Red Sea Hills of Egypt) are characterised by large volumes of post-tectonic, potassic granite. These granites were formed as the final event in the stabilisation of the shields. The potassic granites are absent, or very rare, in presently exposed Archaean terranes, thus causing younger shields to have greater average abundances of lithophilic elements than older shields. Weighted average compostions of exposed surface areas can be plotted for three shields of different age (2500 my, Archaean rooks of the Canadian shield; 1750 my, Proterozoic rocks of the Canadian shield; and 1000 my, Llano uplift of Texas). Extrapolation of these trends to 3500 my yields the following inferred composition of early Archaean crust: SIO 2 , 4.0%; TiC 2 , 0.5%; Al 2 O 3 ; 17.0%; total Fe as Fe 2 O 3 , 5–4%; KgO, 3–1%; CaO, 3.9%; Na 2 O, 4–6%; K 2 O, 1.5%. This inferred composition is sufficiently poor in K 2 O that it is unlikely that significant quantities of potassium feldspar occurred in rocks of this age. The absence of potassium feldspar (and true granites) correlates with the absence of granitic debris in sedimentary rocks formed by the erosion of early Archaean crust. This observation also indicates that early Archaean crust was actually impoverished in potassium, and granitic materials in general, and that the absence of potassic granites from presently exposed older shields is not simply the result of removal of high-level granites by deep erosion of Archaean terranes.
Rethinking Realism: A Critique of Georg Lukács

Word Count: 3,624 In ?The Ideology of Modernism,? Georg Lukacs proposes the following antithesis in order to critique the aesthetic condition of modern subjectivity: ?Abstract potentiality belongs wholly to the realm of subjectivity; whereas concrete potentiality is concerned with the dialectic between the individual?s subjectivity and objective reality? (24). The necessity of such an opposition resides in the aesthetic preservation of ?Realism,? i.e., the commitment to interrogating and discovering the true laws governing objective reality?in short, the uncovering of essence from the distorting images of appearance. Lukacs identifies the emergence of Modernism as a symptom of the impossibility to negotiate, aesthetically, the difference between appearance and essence: ?If the distinction between abstract and concrete potentiality vanishes, if man?s inwardness is identified with an abstract subjectivity, human personality must necessarily disintegrate? (ibid). Despite his dialectical exhortations, my paper will be an attempt to demonstrate that Lukacs? understanding of Realism effectuates an absolutization of ?concrete potentiality? insofar as he reduces the relationship of the literary subject to an essentialized form, namely, an explicit recuperation of Aristotle?s concept of man as a ? zoon politikon ? (31). The circumscription of the literary subject as an immutable absolute?renders eternal, what realist literature has always understood to be temporal. In other words, Lukacs? aesthetic strictures have transformed the immanent forms of literary production into static forms of transcendence.
An improbable journey: Creativity helped me make the transition from art to curing malaria.

I was recently awarded the Alice and C. C. Wang Award in Molecular Parasitology for my contributions to antimalarial drug development, including laying the groundbreaking work that has led to two new molecular methods for curing malaria. This award means a great deal to me because I have spent much of my scientific career feeling like an imposter—one with the wrong sort of background and poor credentials. I am grateful for the recognition, and I am beginning to recognize that having an atypical background can be an advantage because it gives you a different perspective on a challenge. More generally, diversity in educational and cultural backgrounds is important because it can stimulate new ways of thinking and discovery.
Machine Learning for Rapid QSTS Simulations Using Neural Networks

Distribution system analysis with high penetrations of distributed PV requires quasi-static time-series (QSTS) analysis to capture the time-varying and time-dependent aspects of the system, but current QSTS algorithms are prohibitively burdensome and computationally intensive. This paper proposes to identify the key time periods throughout the year that need to be run with QSTS simulation and then predict the number of tap changes for the rest of the time periods using an ensemble of neural networks (NN). This ensemble NN approach is a new method of performing time-step simulations based solely on the input data and demonstrates high accuracy for reproducing the full baseline QSTS analysis while performing the simulation up to 4 times faster.
FAKTOR-FAKTOR YANG MEMPENGARUHI KEPUTUSAN NASABAH PEMBIAYAAN HAJI MEMILIH PEGADAIAN SYARIAH

Hukum ibadah haji adalah wajib bagi setiap muslim yang mampu dari sisi jasmani, rohani dan ekonomi. Salah satu lembaga keuangan yang memberikan penawaran produk pembiayaan haji adalah Pegadian Syariah. Produk pembiayaan haji yang ditawarkan oleh pegadaian syariah adalah Arum Haji. Tabungan Arum haji memudahkan masyarakat berpenghasilan sedang dan rendah untuk segera mendaftarkan haji dengan sistem pembiayaan. Penelitian ini mengunakan metode penelitian survey yaitu suatu penelitian yang mengambil sampel dari suatu populasi dengan mengandalkan kuesioner sebagai instrumen pengumpulan data. Dengan demikian penelitian ini dikategorikan sebagai explanatory research , yaitu penelitian yang menjelaskan hubungan kausal antara variabel-variabel penelitian melalui pengujian hipotesis. Unit analisis dalam penelitian ini adalah Nasabah Pegadaian Syariah Babakan Tangerang yang memutuskan pemilihan produk Arum Haji. Penelitian ini merupakan penelitian kuantitatif. Metode yang digunakan untuk menguji hipotesis adalah dengan uji instrumen data, regresi liner berganda, uji t, uji f dan koefesien determinasi (R2).Hasil penelitian menunjukkan pelayanan (0,432), lokasi (0,164) dan promosi (0,537) berpengaruh signifikan terhadap keputusan nasabah pembiayaan haji memilih pada Pegadaian syariah B abakan Tangerang (Y).
Analysis of Spectrum Allocation to Support Mobile Ad-Hoc Networks in Contested Environments

Military forces are currently developing and fielding mobile ad-hoc network (MANET) radios capable of connecting highly mobile units operating on rugged terrain over long distances. While these radios offer considerable capabilities, including high data rates and automatic traffic relay, they are susceptible to incidental interference from friendly and civilian forces, and the actions of increasingly sophisticated adversaries intent on contesting use of the electromagnetic spectrum. We develop our previous method of efficiently allocating spectrum to now analyze the operation of multiple, independent MANETs in the presence of accidental interference or purposeful jamming. We describe in detail the results of jamming analysis using a realistic data set from a large U.S. Marine Corps combat scenario, and provide observations on the robustness of our optimized channel allocation solutions. We also outline our future research plan for considering adversarial actions using a game-theoretic approach.
Inhibition of glycolysis: a novel strategy to overcome drug resistance in CD133+ tumor initiating cells under hypoxic microenvironment

LB-94 Increasing evidences suggest that the existence of a subpopulation of drug resistant tumor initiating cells or cancer stem cells likely attributes to the failure of clinical cancer treatment and disease recurrence. Development of new strategies to effectively eliminate the cancer stem cells is critical to improve treatment outcomes. Based on our recent observations, we hypothesize that tumor initiation cells (or stem-like cells) favor hypoxic conditions and maintain the stemness through high glycolytic activity, and that glycolytic inhibition might represent a novel approach to eliminating cancer stem cells. To test the hypothesis, we established a CD133+ enriched cell model (U87-SC) by isolating tumor cells from human malignant glioma U87 xenograft pre-selected in vivo by doxorubicin treatment, and maintaining the cells in a simplified brain tumor stem cell medium. At earlier passages, U87-SC cells readily formed neuroshere-like clusters in hypoxia but not in normoxia, indicating that hypoxia significantly favored the maintenance of neurosphere-forming capacity. There was a 2-fold increase of expression of CD133 in hypoxic U87-SC compared with normoxia as analyzed by flow cytometry. Interestingly, the neurosphere phenotype was eventually lost when cells were cultured in regular DMEM with 10% FBS. The neurosphere-like cells highly expressed nestin, a neural progenitor cell marker, suggesting that the neurosphere-forming capacity may reflect a stemness stage in proper culture conditions. Colony formation and anchorage-independent assay in soft-agar showed a higher colony formation capacity for hypoxic U87-SC cells. Furthermore, in vivo tumorigenecity of the hypoxic U87-SC cells was 100-fold higher than the parental U87 cells as quantitatively tested by by inoculation in nude mice. MTT assay showed that hypoxic U87-SC cells were less sensitive to doxorubicin, vincristin, and BCNU compared with normoxic conditions. The residual U87-SC cells after doxorubicin treatment re-grew when the drug was removed. Importantly, the sphere-forming U87-SC cells exhibited less oxygen consumption, and were highly sensitive to glycolytic inhibition, leading to severe ATP depletion. Combination with glycolytic inhibition with doxorubicin was able to eliminate the residual cells and abolish cell re-growth. Apoptosis induction by the combination treatment was confirmed by PARP cleavage and caspase activation using Western blot. Furthermore, this in vitro drug combination treatment effectively eliminated the tumorigenesic capacity of the hypoxic U87-SC cells to form tumors in vivo. Our data suggest that the chemotherapy resistance phenotype of hypoxic brain tumor cells is likely due to an enrichment of highly glycolytic tumor-initiating cells, which can be eliminated by a combination treatment of chemotherapeutic agents with glycolytic inhibition.
Coral Reef Fish Assessment in the ‘Coral Triangle’ of Southeastern Asia

Icthyological results of four rapid assessment surveys are presented. The surveys were completed between 1997–1999 and were conducted at the following localities: Milne Bay (Papua New Guinea), Calamianes Islands (Palawan, Philippines), Togean–Banggai Islands (Sulawesi, Indonesia), and Weh Island (Sumatra, Indonesia). Surveys were conducted over periods ranging from 9 to 22 days and consisted mainly of underwater observations while scuba diving, supplemented with small rotenone and spear gun collections. Milne Bay was characterized by a high percentage of pristine reef environments and supported the largest number of species (1040). Diversity was generally lower at the Philippine and Indonesian sites due to more habitat homogeneity and higher fishing pressure, including the widespread use of illegal fishing methods, including cyanide and explosives.
Cardiac Transplantation Outcomes in Patients with Amyloid Cardiomyopathy

Objective Amyloid cardiomyopathy (ACM) is a progressive and life-threatening disease characterized by abnormal proteinaceous deposits within the cardiac extracellular space. The most common forms of ACM are caused by immunoglobulin derived light chains (AL) and transthyretin (TTR). Although the management for each entity is different, heart transplant (HT) remains the definitive treatment for patients who progress to end stage heart failure. To date there is no consensus regarding the usage of heart transplantation in patients with ACM, and studies have shown mixed results. In this study, we perform a contemporary multi-center analysis evaluating post HT survival in patients with ACM. Methods We conducted a multi-center analysis of 62588 adult HT recipients captured in the United Network for Organ Sharing (UNOS) registry from 1987-2018. Patients were characterized as ACM or Non-ACM. Baseline characteristics were obtained, and summary characteristics were calculated. Outcomes of interest included post-transplant survival, infection, treated rejection, and the ability to return to work. Unadjusted associations between ACM and non-ACM survival were determined using the Kaplan-Meier estimations and confounding was addressed using multivariable Cox proportional hazards models. Results 398 patients with a diagnosis of ACM were identified. ACM patients were older (61 vs 52 p= Conclusion In this analysis of HT in ACM, ACM was associated with a higher likelihood of post HT mortality. No differences were observed in episodes of treated rejection, hospitalization for infection or likelihood to return to work for income. Further analysis is warranted to establish the mechanism of higher mortality in ACM patients.
Research note: LED lighting – A global enterprise:

There is considerable focus on technology manufacturing locations and the value in funding innovation when upstream products are not manufactured within a domestic economy. Light-emitting diodes (L...
On These Holy Mountains

Chaplains are charged with the essential task of reflecting on their experiences and developing their insights into formats that can be shared with others. This brief report summarizes the spiritua...
The Viral Macrodomain Counters Host Antiviral ADP-Ribosylation

Macrodomains, enzymes that remove ADP-ribose from proteins, are encoded by several families of RNA viruses and have recently been shown to counter innate immune responses to virus infection. ADP-ribose is covalently attached to target proteins by poly-ADP-ribose polymerases (PARPs), using nicotinamide adenine dinucleotide (NAD+) as a substrate. This modification can have a wide variety of effects on proteins including alteration of enzyme activity, protein-protein interactions, and protein stability. Several PARPs are induced by interferon (IFN) and are known to have antiviral properties, implicating ADP-ribosylation in the host defense response and suggesting that viral macrodomains may counter this response. Recent studies have demonstrated that viral macrodomains do counter the innate immune response by interfering with PARP-mediated antiviral defenses, stress granule formation, and pro-inflammatory cytokine production. Here, we will describe the known functions of the viral macrodomains and review recent literature demonstrating their roles in countering PARP-mediated antiviral responses.
Factors Associated with Reoperation after Pyrocarbon Proximal Interphalangeal Joint Arthroplasty for the Arthritic Joint: A Retrospective Cohort Study.

Introduction The rate of reoperation after pyrocarbon proximal interphalangeal (PIP) joint arthroplasty ranges from 5.9 to 37% and complications such as radiographic loosening, deformity, dislocation, and stiffness are common. Because of the limited amount of knowledge around these problems, we evaluated factors associated with reoperation after pyrocarbon PIP arthroplasty. Materials and Methods We retrospectively included all adult patients that underwent primary PIP pyrocarbon implant arthroplasty between 2002 and 2016 at one institutional system. A total of 45 patients, with a mean age of 55 (standard deviation: 14), underwent 66 PIP arthroplasties. To address for within individual correlations, we only included fingers treated at patients’ initial surgery (n = 54) in our statistical analysis. These patients were predominantly diagnosed with noninflammatory arthritis 73% (n = 33). Arthroplasty was performed upon 10 index, 22 middle, 20 ring, and 2 small fingers. Results The reoperation rate after pyrocarbon PIP arthroplasty was 30% over a median follow-up of 25 months (interquartile range: 8.7–54). Indications for reoperation consisted of subluxation (n = 6), stiffness (n = 5), swan-neck deformity (n = 3), and soft tissue complications (n = 2). Younger age (p = 0.025), male sex (p = 0.017), and noninflammatory arthritis (p = 0.038) were associated with a higher reoperation rate. Conclusion In this study, our reoperation rate after pyrocarbon PIP arthroplasty was 30%. This study suggested that younger patients, males, and patients with noninflammatory arthritis are at higher risk of reoperation. We recommend considering these factors when selecting candidates for pyrocarbon arthroplasty. Future studies should focus on prospectively researching these factors in comparison with other implants.
Urban Transformation for Sustainable Growth and Smart Living: The Case of the Atlanta Beltline

The Beltline project in Atlanta combines elements of urban greenway planning, parks and recreation, pedestrian and bike friendly trails, public transit, and other facilities connecting over 40 neighborhoods. This is bringing about transformative urban regeneration in those neighborhoods, with large-scale economic investments and growth in previously neglected areas and brownfields. The Beltline has generated considerable interest among urban scholars. However, most studies have focused on specific aspects of the Beltline development in detail. This study uses extensive literature review and analyzes census data while taking a comprehensive look at the following smart living perspectives: urban health and wellbeing, smart public transportation, economic development and brownfields, and managing affordable housing during neighborhood change. While the Beltline has brought about considerable growth and investment, and created city level green spaces and trails, the process has been accompanied by gentrification and displacement that has disproportionately affected the racial minorities and poor neighborhoods.
Med-BERT: pre-trained contextualized embeddings on large-scale structured electronic health records for disease prediction

Deep learning (DL) based predictive models from electronic health records (EHR) deliver impressive performance in many clinical tasks. Large training cohorts, however, are often required to achieve high accuracy, hindering the adoption of DL-based models in scenarios with limited training data size. Recently, bidirectional encoder representations from transformers (BERT) and related models have achieved tremendous successes in the natural language processing domain. The pre-training of BERT on a very large training corpus generates contextualized embeddings that can boost the performance of models trained on smaller datasets. We propose Med-BERT, which adapts the BERT framework for pre-training contextualized embedding models on structured diagnosis data from 28,490,650 patients EHR dataset. Fine-tuning experiments are conducted on two disease-prediction tasks: (1) prediction of heart failure in patients with diabetes and (2) prediction of pancreatic cancer from two clinical databases. Med-BERT substantially improves prediction accuracy, boosting the area under receiver operating characteristics curve (AUC) by 2.02-7.12%. In particular, pre-trained Med-BERT substantially improves the performance of tasks with very small fine-tuning training sets (300-500 samples) boosting the AUC by more than 20% or equivalent to the AUC of 10 times larger training set. We believe that Med-BERT will benefit disease-prediction studies with small local training datasets, reduce data collection expenses, and accelerate the pace of artificial intelligence aided healthcare.
Adherence to buprenorphine treatment guidelines among individuals with an opioid use disorder who have private insurance

Abstract Background Although treatment of opioid use disorders (OUD) with medications is expanding, the extent to which practitioners are prescribing medications following best practices has received little attention. Objective The aim of this study was to determine the extent to which privately insured patients being treated for OUD with buprenorphine were treated in a manner consistent with practice guidelines. Design Longitudinal analyses of a large commercial claims dataset from 2012 to 2016. Participants We analyzed data for 38,517 patients with an OUD diagnosis continuously enrolled for 3 months prior to and 6 months after an initial buprenorphine or buprenorphine–naloxone prescription fill. Main measures We evaluated whether practitioners tested patients for hepatitis B, hepatitis C, HIV, and liver function; how often they received urine drug screens; the frequency of outpatient visits; and the extent to which they filled prescriptions for buprenorphine for at least 6 months. Key results Practitioners tested approximately 4.7% of patients for hepatitis B, 6.5% for hepatitis C, and 29.3% for HIV; they tested 8.0% for liver functioning; and gave 33.3% urine drug tests. Approximately 76% of patients had at least one outpatient visit for their OUD. Among those with at least one visit, the mean number of visits was 7.38. After the initial prescription, 47.5% stayed on buprenorphine for at least 6 months. Conclusions A large portion of privately insured patients receiving buprenorphine for OUD did not receive care consistent with guidelines.
Density matrix renormalization group in a two-dimensional λϕ4 hamiltonian lattice model

Density matrix renormalization group (DMRG) is applied to a (1+1)-dimensional λ4 model. Spontaneous breakdown of discrete Z2 symmetry is studied numerically using vacuum wavefunctions. We obtain the critical coupling (λ/μ2)c = 59.89 ± 0.01 and the critical exponent β = 0.1264 ± 0.0073, which are consistent with the Monte Carlo and the exact results, respectively. The results are based on extrapolation to the continuum limit with lattice sizes L = 250, 500, and 1000. We show that the lattice size L = 500 is sufficiently close to the the limit L → ∞.
Video-based HIV testing services among cisgender men who have sex with men as a component of an HIV behavioural surveillance study during the COVID-19 pandemic in New York City: implementation, feasibility and lessons learned.

HIV self-testing (HIVST) provides an opportunity for overcoming barriers to in-person HIV testing, and it has been shown to be generally preferable among populations at increased risk for HIV1 and effective in increasing HIV testing uptake.2–4 Within research, HIVST has mostly been incorporated into studies that aim to increase HIV testing uptake and less frequently in studies that aim to verify HIV status. Barriers to using HIVST as a method to confirm HIV status include missing data due to reliance on self-report and challenges to verifying self-report.5 HIVST through videoconferencing (video-based HIVST) may overcome these barriers as it allows for the visual verification of testing and of the test result without relying on participant follow-up, and it can serve as a viable virtual strategy in HIV research. From November 2020 to January 2021, we implemented video-based HIVST as an alternative to in-person HIV testing, as a component of the CDC’s National HIV Behavioral Surveillance Study (NHBS) among cisgender men who have sex with men in New York City. NHBS methods are described elsewhere. …
Crash Cart Usability: A Method in Simulation & Iterative Design:

Prior to implementation, front line clinical staff assessed a new crash cart in a simulated environment.The contents of the cart were assessed during a simulated code on a number of metrics; time o...
The genesis of urban music in Zaire

In Zaire, the installation of radio stations and recording industries gave rise to an urban musical expression which fed on traditional music for its content, and relied heavily on foreign musical instruments as a medium of interpretation. The organization of the newly created musical expression was governed by norms of aesthetics peculiar to the new urban centers.
Gene-Environment Interactions in Human Health

Risk of most complex diseases is determined by a combination of environmental and genetic factors. By studying gene-environment interactions, it may be possible to describe disease mechanisms, discover novel genetic variants associated with disease, better understand heterogeneity between populations, identify populations with higher risk from exposure, and target preventive and therapeutic interventions. However, there are several challenges to the study of gene-environment interactions. As technologies and analytical tools improve, opportunities to better understand the complex interplay between genes and environment may result in improved insights in disease and treatment outcomes.
Efficient in vivo gene transfer to murine renal cells using AAV9 vectors (912.7)

Adeno-associated viral (AAV) vectors provide sustained long-term gene expression with minimal immunological consequences. Therefore AAV vector systems are useful gene-transfer tools in translationa...
El proceso emprendedor en Chile

Este estudio analiza los factores que afectan en forma positiva y negativa el proceso de creacion de emprendimientos dinamicos en Chile. Se basa en una encuesta a 200 empresas jovenes, la cual es parte de una muestra de casi 2000 empresas de America Latina. El presente estudio se enfoca basicamente en el segmento de nuevos emprendimientos existentes en Chile.
Raman investigation of the YBa2Cu3O7 imaginary response function.

Results on the temperature dependence of the imaginary component of the response function R''(\ensuremath{\omega}) in an untwinned ${\mathit{T}}_{\mathit{c}}$\ensuremath{\sim}90 K Y-Ba-Cu-O crystal are presented. We find that the normal-state imaginary parts of the response functions for the distinct ${\mathit{A}}_{1\mathit{g}}$ and ${\mathit{B}}_{1\mathit{g}}$ symmetries exhibit behavior characteristic of a quasielastic-scattering mechanism, having a temperature and frequency-dependent relaxation rate. Further, the zero-frequency resistivities for the two symmetries inferred from this quasielastic model closely resemble the measured resistivity for single crystals of this material. Finally, a low-energy linearity of the ${\mathit{B}}_{1\mathit{g}}$ imaginary response function, accurately described in the normal state by this model in the limit \ensuremath{\omega}\ensuremath{\le}T, is found to persist in the superconducting state but an analysis of the slope reveals a dramatic alteration at ${\mathit{T}}_{\mathit{c}}$.
Hawaii's "7 by 7" for school health education: a PowerPoint presentation on integrating the national health education standards with priority content areas for today's school health education in grades kindergarten through 12.

School-based health education can help young people develop the knowledge, skills, motivation, and support they need to choose health-enhancing behaviors and resist engaging in behaviors that put them at risk for health and social problems and school failure. The health of school-age youth is significantly associated with their school achievement. However, in the midst of today's increased emphasis on school accountability in the areas of reading, writing, and mathematics, subject areas such as health education tend to receive less prominence in the school curriculum. Recalling their own lackluster school experiences related to health topics, decision makers may not realize that today's skills-based school health curriculum involves a highly interactive and engaging approach to promoting good health and preventing the most serious health problems among youth. Health education is one important component of a coordinated school health program that includes health education, physical education, school health services, nutrition services, school counseling and psychological services, a healthy school environment, school promotion for faculty and staff, and involvement of family and community members. The purpose of this PowerPoint presentation — Healthy Keiki, Healthy Hawaii: Hawaii's "7 by 7" for School Health Education — is to educate health and education decision makers, teachers, parents, and community members on how Hawaii has integrated seven health education standards with seven priority health content areas to create an effective approach to school health education in grades kindergarten through 12. The goal of Hawaii's "7 by 7" curriculum focus is to ensure that all of Hawaii's keiki (children) have well-planned opportunities at school to become fit, healthy, and ready to learn.
Neurodegeneration: Evolved protection against human prions

A genetic variant of PrP, the protein that forms prions, confers protection against the human prion disease kuru by inhibiting the conversion of functional isoforms to the abnormal, disease-causing conformation. See Letter p.478 Long-term studies in Papua New Guinea, where the prion disease kuru has been endemic, identified a polymorphism of the human prion protein (PrP) gene — a glycine to valine substitution at residue 127 — that provided a high degree of protection from kuru and was positively selected for during the kuru epidemic. Here John Collinge and colleagues study this G127V polymorphism in detail in transgenic mice expressing different human prion proteins. Mice heterozygous for the G127V polymorphism, which mirrors the human genotype found in Papua New Guinea, are resistant to both kuru and classical Creutzfeldt–Jakob disease (CJD) prions, but there was some transmission of variant CJD, a bovine spongiform encephalopathy (BSE)-derived strain that the humans in Papua New Guinea were never exposed to. Most remarkably, however, mice homozygous for 127V were completely resistant to all prion strains. This represents a previously unknown mechanism of protection against prions; the more common polymorphism M129V is protective only in the heterozygous state. How a single amino acid change can offer such protection awaits further studies.
Maximum Entropy Models

Department of Linguistics and Asian/Middle Eastern LanguagesSan Diego State University5500 Campanile DrSan Diego, CA 92182USArmalouf@mail.sdsu.eduA draft chapter for the Blackwell Computational Linguistics and Natural Lan-guage Processing Handbook, edited by Alex Clark, Chris Fox and Shalom Lappin.This draft formatted on 1st October 2008.
Incremental Map Generation (IMG)

Probabilistic roadmap methods (prms) have been highly successful in solving many high degree of freedom motion planning problems arising in diverse application domains such as traditional robotics, computer-aided design, and computational biology and chemistry. One important practical issue with prms is that they do not provide an automated mechanism to determine how large a roadmap is needed for a given problem. Instead, users typically determine this by trial and error and as a consequence often construct larger roadmaps than are needed. In this paper, we propose a new prm-based framework called Incremental Map Generation (img) to address this problem. Our strategy is to break the map generation into several processes, each of which generates samples and connections, and to continue adding the next increment of samples and connections to the evolving roadmap until it stops improving. In particular, the process continues until a set of evaluation criteria determine that the planning strategy is no longer effective at improving the roadmap. We propose some general evaluation criteria and show how to apply them to construct different types of roadmaps, e.g., roadmaps that coarsely or more finely map the space. In addition, we show how img can be integrated with previously proposed adaptive strategies for selecting sampling methods. We provide results illustrating the power of img.
Validation of a bowel dysfunction instrument for adolescents with spina bifida.

Introduction Existing survey instruments for bowel dysfunction in the pediatric population are either parent-reported or focus on non-neurogenic bowel dysfunction. Objective The purpose of this study was to develop and validate an adolescent-reported survey to assess the severity of bowel dysfunction in spina bifida patients and examine its impact on quality of life (QOL). Study design We performed a cross-sectional study of patients in our Myelodysplasia Program, aged 11–17 years, with a history of constipation and/or fecal incontinence (FI) from November 2010 to June 2013. Control patients, aged 11–17 years, were recruited from the stone clinic. Exclusion criteria were lack of English fluency, insufficient reading skills, or an incontinent fecal diversion. A 29-item version of the Adolescent Fecal Incontinence and Constipation Symptom Index (A-FICSI) was developed with five domains (Figure). Test re-test reliability and correlation with the total global health-related QOL score from the Parkin survey were measured using the Pearson correlation coefficient. A factor analysis model with four-fold correlations was tested. Results Of the 65 study-eligible individuals approached, 25 (11 boys) completed the A-FICSI (median age 12.6 years, IQR 11.8–14.7 years) and 17 completed another survey on urinary incontinence (64.6% response rate). Twenty-one control patients with nephrolithiasis completed the A-FICSI. Nine of the 25 completed a second administration of the survey. The mean correlation between repeated administrations of the survey was r = 0.43. There was a significant negative correlation between severity of constipation (r = −0.299, p 0.30) in the predicted direction. Unstandardized residuals were 8.7% (95% CI 6.4–10.9%). Item reduction was performed on the 29-item instrument based on results of the factor analysis. The finalized instrument contained 21 items. Discussion This is the first adolescent-reported bowel dysfunction instrument to undergo formal psychometric assessment in the spina bifida population. The instrument demonstrated adequate reliability and the five-factor structure fit the data well. This study highlights the negative impact of bowel dysfunction on the QOL of spina bifida patients. It is limited by the moderate sample size that is a common issue in relatively rare diseases. Conclusion The A-FICSI possesses desirable psychometric properties for the measurement of bowel dysfunction in the spina bifida population. Figure. Conceptual model of the Adolescent Fecal Incontinence and Constipation Symptom Index. Figure options Download full-size image Download high-quality image (276 K) Download as PowerPoint slide
Quantitative Analysis of Firing Properties of Pyramidal Neurons From Layer 5 of Rat Sensorimotor Cortex

Quantitative aspects of repetitive firing evoked by injected current steps and ramps were studied in layer 5 pyramidal neurons in brain slices of rat sensorimotor cortex to answer the following questions. Do the tonic firing properties of burst-firing and regular-spiking (nonbursting) neurons differ significantly? Does burst firing denote a discrete class of neurons or represent a continuum of firing properties? Is firing rate during the burst of action potentials related to stimulus amplitude? What aspect of the stimulus might the initial firing rate code? How stable are a neuron's firing properties over time? All recorded neurons fired tonically to a long-lasting current above a minimum value, and the tonic firing properties of most neurons were quite similar irrespective of their initial response to a current step. Only a group of high-resistance neurons had significantly different tonic firing properties. When slow current ramps (rising between 0.5 and approximately 20 nA/s) were applied, the relation between firing rate and current during the ramp was very similar to the relation between tonic firing rate and current obtained from long-lasting current steps. Low-resistance cells exhibited three distinct initial responses to a current step: fast adaptation, high-threshold bursts, and low-threshold bursts, observed in 54, 28, and 10% of recorded cells, respectively. High-resistance cells exhibited a distinctive slow adaptation of firing rate. Slowly adapting, fast-adapting (FA), and high-threshold burster (HTB) neurons exhibited no adaptation near the minimum current that evoked repetitive firing (I(o)). FA and HTB cells exhibited two-spike adaptation to a fina tonic firing rate during currents up to 1.6 times I(o). Only a higher current (2.1 times I(o)) evoked a burst in HTB cells, whereas a burst was evoked at I(o) in the low-threshold burster cells. In most cells analyzed, the initial firing rate, whatever its nature, increased monotonically with current step amplitude. The response to fast current ramps indicated that firing rate during adaptation or bursting may code rate of change of current. Repeated measurements during long-duration impalements indicated that both transient and tonic firing properties are stable over time. We discuss how the different tonic firing properties of large and small pyramidal neurons could be more important functionally than the different transient responses (burst/nonburst) of the large neurons. We conclude that the large neurons would perform a better linear transduction of time-varying synaptic current that reaches their somata. We compare the responses evoked by somatically injected current with those evoked by dendritic glutamate iontophoresis in previous studies.
THIALYSINE-RESISTANT MUTANT OF SALMONELLA TYPHIMURIUM WITH A LESION IN THE thrA GENE

A mutant of Salmonella typhimurium was selected for its spontaneous resistance to the lysine analog, thialysine (S-2-aminoethyl cysteine). This strain, JB585, exhibits a number of pleiotropic properties including a partial growth requirement for threonine, resistance to thiaisoleucine and azaleucine, excretion of lysine and valine, and inhibition of growth by methionine. Genetic studies show that these properties are caused by a single mutation in the thrA gene which encodes the threonine-controlled aspartokinase-homoserine dehydrogenase activities. Enzyme assays demonstrated that the aspartokinase activity is unstable and the threonine-controlled homoserine dehydrogenase activity absent in extracts prepared from the mutant. These results explain the growth inhibition by methionine because the remaining homoserine dehydrogenase isoenzyme would be repressed by methionine, causing a limitation for threonine. The partial growth requirement for threonine during growth in glucose minimal medium may also, by producing an isoleucine limitation, cause derepression of the isoleucine-valine enzymes and provide an explanation for both the valine excretion, and azaleucine and thiaisoleucine resistance. The overproduction of lysine may confer the thialysine resistance.
The Importance of Oscillatory Structural Forces in the Sedimentation of a Binary Hard-Sphere Colloidal Suspension

Concentrated colloidal dispersions are complex systems comprised of colloidal particles of various sizes. This paper summarizes recent experimental and theoretical findings on understanding the interactions between microspheres in the presence of submicrometer particles; the submicrometer particles can be solvent molecules, surfactant micelles, or other nanometer-sized particles. In a hard-sphere suspension containing microspheres in the presence of submicrometer particles, oscillatory structural (entropic) forces between large particles, caused by small particles, arise as a result of the collective particle−particle interactions. The magnitude of the oscillatory structural forces is theoretically estimated based on the statistical mechanics approach, Monte Carlo simulations, and stochastic particle dynamics methods. Also, sedimentation experiments using spherical low-charged, binary hard-sphere particle suspensions with a large size ratio are presented to elucidate the importance of the oscillatory stru...
Epileptic seizures are characterized by changing signal complexity.

Abstract Objective : Epileptic seizures are brief episodic events resulting from abnormal synchronous discharges from cerebral neuronal networks. The traditional methods of signal analysis are limited by the rapidly changing nature of the EEG signal during a seizure. Time–frequency analyses, however, such as those produced by the matching pursuit (MP) method can provide continuous decompositions of recorded seizure activity. These accurate decompositions can allow for more detailed analyses of the changes in complexity of the signal that may accompany seizure evolution. Methods : The MP algorithm was applied to provide time–frequency decompositions of entire seizures recorded from depth electrode contacts in patients with intractable complex partial seizures of mesial temporal onset. The results of these analyses were compared with signals generated from the Duffing equation that represented both limit cycle and chaotic behavior. Results : Seventeen seizures from 12 different patients were analyzed. These analyses reveal that early in the seizure, the most organized, rhythmic seizure activity is more complex than limit cycle behavior, and that signal complexity increases further later in the seizure. Conclusions : Increasing complexity routinely precedes seizure termination. This may reflect progressive desynchronization.
Manual obstacle avoidance takes into account visual uncertainty, motor noise, and biomechanical costs

Moving around obstacles requires balancing the need to avoid collisions with the need to minimize biomechanical costs. We investigated this tradeoff by studying the effects of visual uncertainty, motor noise, and practice on clearance over obstacles in a manual positioning task. Participants moved a manipulandum back and forth over a stationary obstacle. We varied visual uncertainty by placing the obstacle at different heights relative to participants' eyes, and we varied motor noise by having participants hold the object to be moved at different positions relative to the range of motion of the arm joints. Clearance was larger in conditions of higher visual uncertainty than in conditions of lower visual uncertainty, larger in the higher motor noise conditions than in the lower motor noise conditions, and larger early in practice than late in practice. The results indicate that spatial accuracy and biomechanical costs are both taken into account during reaching over obstacles, but to differing degrees across practice.
Selective electrocatalytic reduction of CO2 to formate by water-stable iridium dihydride pincer complexes.

Iridium dihydride complexes supported by PCP-type pincer ligands rapidly insert CO2 to yield κ2-formate monohydride products in THF. In acetonitrile/water mixtures, these complexes become efficient and selective catalysts for electrocatalytic reduction of CO2 to formate. Electrochemical and NMR spectroscopic studies have provided mechanistic details and structures of key intermediates.
Amperometry of thiols in a flow-injection system with a nickel oxide electrode

Abstract The electrochemical oxidation of a series of thils on the surface of a nickel oxide electrode is investigated in a flow-injection system. The background electrolyte is 0.1 M NaOH containing 5 × 10−65 M NiSO4 and the injected sample volume is 25 μl. The net peak current is observed at +0.46 V vs. SCE for thiols dissolved in pH 3.0 phthalate buffer. The upper limit of linearity extends to 10−3 M. The relative standard deviation for ten replicate measurements on 10−4 M ethanethiol is 1.6%. The lower limits of detection are between 3 × 10−5 and 2 × 10−4 M for a series of thiols. Peak shapes indicate that thiolate oxidation mediated by a higher oxide layer on the electrode rather than mass transport or adsorption / rearrangement is the rate-determining step.
Shooting from the hip: Spatial control of signal release by intracellular waves

The versatility of cell–cell communication relies on sophisticated modules for signal generation, transmission, detection, and processing (1). Compared with signal detection and intracellular processing, signal release is relatively poorly understood. For instance, even though the epidermal growth factor receptor (EGFR) signaling network has been extensively studied over the past 4 decades, the molecules that mediate release of EGFR ligands are being identified only now (2–5). The outstanding issues in signal release are similar to the ones studied in the context of signal detection and processing (6). What are the basic patterns in the dynamic release of small molecules, ions, and hormones? What are the constraints on the time scales of signal release imposed by the corresponding time scales of the signal transmission and detection? Finally, can a cell point its signals toward its neighbors, in a way similar to aiming a gun at a target or to directing electromagnetic and acoustic signals in man-made communications networks?
Quantitative Comparison of Whistle Repertoires from Captive Adult Bottlenose Dolphins (Delphinidae, Tursiops truncatus): a Re‐evaluation of the Signature Whistle Hypothesis

The prevailing view among researchers of dolphin communication is that bottlenose dolphins possess an individualized whistle contour; known as the ‘signature whistle’, it accounts for 74–95 % of a dolphin's whistle repertoire and functions to signal the individual identity of the whistler. This study used a new quantitative technique, termed the contour similarity technique (CS technique), and reports on the quantitative comparison of whistles from the individuals of three different social groups of bottlenose dolphins in socially interactive contexts. Results suggest that captive adult dolphins share several different whistle types including one predominant whistle type shared by all individuals across three different social groups. These analyses suggest a different interpretation of the dolphin whistle repertoire than has previously been proposed by proponents of the signature whistle hypothesis. In addition, results from our study support the results of early studies, published before the advent of the signature whistle hypothesis, in which investigators reported a large whistle repertoire within socially interactive captive and free-ranging groups and a predominant whistle type similar to that found in our study. Our results, combined with the results from earlier studies of dolphin vocal behaviour, suggest that the signature whistle hypothesis is incomplete and that dolphin whistle repertoires need to be analysed with respect to behavioural context and social relationships. In addition, these results suggest that contour discrimination and other acoustic features of whistles need to be tested in perception and categorization experiments.
Plant Biomechanics: Using Shape to Steal Motion

For grass species to spread efficiently through their environment requires seeds that can disperse over large distances and burrow into the ground. Recent work using awns from Hordeum murinum in conjunction with mathematical modelling shows that awn shape leverages environmental oscillations in order to produce these directional translations.