cssi/SciSciGPT-SciSciNet huggingface dataset:
Potential Spreading Dynamics of COVID-19 with Temporary Immunity – A Mathematical Modeling Study

COVID-19 is caused by a hitherto nonexistent pathogen, hence the immune response to the disease is currently unknown. Studies conducted over the past few weeks have found that the antibody titre levels in the blood plasma of infected patients decrease over time, as is common for acute viral infections. Fully documented reinfection cases from Hong Kong, India, Belgium and USA, as well as credible to anecdotal evidence of second-time cases from other countries, bring into sharp focus the question of what profile the epidemic trajectories may take if immunity were really to be temporary in a significant fraction of the population. Here we use mathematical modeling to answer this question, constructing a novel delay differential equation model which is tailored to accommodate different kinds of immune response. We consider two immune responses here : (a) where a recovered case becomes completely susceptible after a given time interval following infection and (b) where a first-time recovered case becomes susceptible to a lower virulence infection after a given time interval following recovery, and becomes permanently immunized by a second infection. We find possible solutions exhibiting large number of waves of disease in the first situation and two to three waves in the second situation. Interestingly however, these multiple wave solutions are manifest only for some intermediate values of the reproduction number R, which is governed by public health intervention measures. For sufficiently low as well as sufficiently high R, we find conventional single-wave solutions despite the short-lived immunity. Our results cast insight into the potential spreading dynamics of the disease and might also be useful for analysing the spread after a vaccine is invented, and mass vaccination programs initiated.
Current Procedural Terminology-based Procedure Categorization Enhances Cost Prediction of Medicare Severity Diagnosis Related Group in Spine Surgery.

STUDY DESIGN Retrospective cohort study. OBJECTIVE The aim of this study was to analyze how a Current Procedural Terminology (CPT)-based categorization method can predict cost variation in surgical spine procedures. SUMMARY OF BACKGROUND DATA Neck and back disorders affect a majority of the adult population and account for tens of billions of dollars in health care spending each year. In the era of bundled payments and value-based reimbursement, it is imperative for surgeons to identify sources of cost variability across surgical spine procedures. Historically, this has been accomplished using Medicare Severity Diagnosis Related Group (MS-DRG) codes, but they utilize an overly simplistic categorization of surgical procedures. The specificity and familiarity of the CPT coding structure makes it a better option for categorizing differences in surgical decision making and technique. METHODS Hospital billing data for patients undergoing a surgical spine procedure requiring an overnight, in-patient stay was retrospectively collected over 4 fiscal years (2012-2016) from a single health care system. Linear regression analysis was performed to assess the correlation between cost variation and: spine-specific MS-DRG codes; a novel CPT-based categorization method; and the combination of MS-DRG codes and CPT-based categorization. RESULTS There were 5020 surgical procedures were analyzed with respect to 16 different MS-DRG codes and 30 distinct CPT-based surgical categories (CSCs). Linear regression results were: MS-DRG R2 = 0.6545 (P < 0.001); CSC R2 = 0.5709 (P < 0.001); and R2 = 0.744 for the combined MS-DRG and CSC methods (P < 0.05). Median difference between the actual and predicted cost for the combined model was -$261.00, compared with -$727.50 for the CSC model and -$478.70 for the MS-DRG model. CONCLUSION Addition of the CPT-based categorization method to MS-DRG coding provides an enhanced method to evaluate the association between predicted and actual cost when using linear regression analysis to assess cost variation in spine surgery.Level of Evidence: 3.
Genomics and genre

"If the double helix is an icon of the modern age, then the genome is one of the last grand narratives of modernity," writes Lara Choksey in her new book, Narrative in the Age of the Genome. Hybridizing literary criticism with a genre-spanning consideration of a dozen distinct literary works, and imbued throughout with deep concern for the peripheral, the possible, and the political, the book seeks to challenge the "whole imaginative apparatus for constructing the self into a coherent narrative, via the lexicon and syntax of the molecular."
The pink elephant in the room: Declining public interest in breast cancer and the impact of marketing efforts

Abstract Background Public interest in breast cancer is associated with breast cancer awareness month. However, no study has analyzed the temporal trends in breast cancer interest or assessed how funding for breast cancer research is influenced by public interest. Methods We performed a cross-sectional analysis of Google Trends using the search query “Breast Cancer” between January 2004 - July 2020. We then computed bivariate correlations to assess the association between relative search interest (RSI) and the financial records of the Susan G. Komen Foundation. Results Average search interest has declined since 2004. We identified increasing breast cancer RSI beginning in October 2009, corresponding with breast cancer awareness month, with an overall peak in 2012 followed by a downtrend through 2017. These fluctuations in peak RSI corresponded with the U.S. National Football League’s initiation of “Pink October” during which the players wore pink jerseys which started in 2009 and ceased in 2017. We also found a strong correlation between peak RSI and Susan G. Komen Foundation net assets as well as funding of public health screening services and public health education. Conclusions Average interest in breast cancer has been declining since 2004 and peak interest, as well as breast cancer funding, has been declining since 2012. This suggests new marketing efforts are needed to improve breast cancer awareness and to increase fundraising. Policy Summary Considering the decline in breast cancer interest and funding, we recommend implementing local, regional, and national policies that improve marketing campaigns and improve breast cancer awareness.
An evaluation of ledipasvir + sofosbuvir for the treatment of chronic hepatitis C infection.

Introduction: Hepatitis C (HCV) is viral disease with a global impact. Over the last 10 years, the treatment of this disease has evolved. Treatment guidelines have evolved to adopt new medications ...
Risk factors for prolonged air leak and need for intervention following lung resection.

OBJECTIVES Prolonged air leak (PAL; >5 days) following lung resection is associated with postoperative morbidity. We investigated factors associated with PAL and PAL requiring intervention. METHODS Retrospective review of all patients undergoing lobectomy, segmentectomy or wedge resection from 2016 to 2019 at our institution. Bronchoplastic reconstructions and lung-volume reduction surgeries were excluded. Incidence and risk factors for PAL and PAL requiring intervention were evaluated. RESULTS In total, 2384 patients were included. PAL incidence was 5.4% (129/2384); 22.5% (29/129) required intervention. PAL patients were more commonly male (56.6% vs 39.7%), older (mean age 69 vs 65 years) and underwent lobectomy or thoracotomy (all P < 0.001). Patients with PAL had longer length of stay (9 vs 3 days), more discharge needs and increased odds of complication (all P < 0.050).Twenty-nine patients required intervention (9 chest tubes; 4 percutaneous drains; 16 operations). In 50% of operative interventions, an air leak source was identified; however, the median time from intervention to resolution was 13 days. Patients requiring intervention had increased steroid use, lower diffusion capacity for carbon monoxide and twice the length of stay versus PAL patients (all P < 0.050).On univariable analysis, forced expiratory volume in 1 s (FEV1) <40%, diffusion capacity for carbon monoxide <50%, steroid use and albumin <3 had increased odds of intervention (P < 0.050). CONCLUSIONS Age, gender and operative technique were related to PAL development. Patients with worse forced expiratory volume in 1 s or diffusion capacity for carbon monoxide, steroid use or poor nutrition were less likely to heal on their own, indicating a population that could benefit from earlier intervention.
Constitutive endothelin-1 overexpression promotes smooth muscle cell proliferation via an external autocrine loop

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide originally purified from endothelial cell-conditioned medium. It has multiple biological activities and has been implicated in a number of human diseases, including hypertension and atherosclerosis. Contradictory reports have been published regarding whether ET-1 is a mitogen for vascular smooth muscle cells (SMC); thus, this issue is presently unresolved. In this study, we demonstrate that rat aortic SMC express functional endothelin cell surface receptors but do not proliferate when ET-1 is added to serum-free culture medium on every other day for a period of 1 week. To determine whether ET-1 could function in an autocrine manner to promote SMC growth, we transfected this same cell line with an ET-1 expression plasmid. Several independent lines expressing variable levels of ET-1 mRNA and biologically active ET-1 were obtained. Cell proliferation assays indicated that the transfected SMC line secreting the highest level of ET-1 had an enhanced growth rate when compared with untransfected or vector-alone transfected cells. The growth rate of this SMC line, but not of untransfected cells, was significantly reduced when the ETA receptor subtype-selective antagonist BQ-123 was included in the culture medium. These results indicate that constitutive ET-1 overexpression can promote SMC proliferation. Therefore, it is possible that under certain conditions ET-1 could be an important factor controlling SMC replication in vivo.
Decreased proteoglycan synthesis associated with form deprivation myopia in mature primate eyes.

PURPOSE. The rate of proteoglycan synthesis was measured in the scleras of adolescent marmosets that had undergone monocular form deprivation to characterize the scleral extracellular matrix changes associated with the development of myopia in a mature primate. METHODS. Form deprivation myopia was induced in adolescent marmosets by unilateral lid suture for an average of 108 days. After the lids were reopened, the axial lengths and refractions were measured at intervals for up to 39 weeks. At the end of the study period, sclera were isolated and immediately radiolabeled with 35 SO4 in organ culture. Proteoglycan synthesis rates were determined by measurement of 35 SO4 incorporation into cetylpyridinium chloride‐precipitable glycosaminoglycans after digestion of the scleral samples with proteinase K. Collagen content was determined by measurement of total hydroxyproline in scleral digests. Newly synthesized proteoglycans were separated on a Sepharose CL-4B molecular sieve column and identified by their core proteins by Western blot analyses. RESULTS. Lid suture resulted in myopia due to a significant increase in vitreous chamber depth. After Sepharose CL-4B chromatography, newly synthesized scleral proteoglycans isolated from normal, form-deprived, and contralateral control eyes, resolved into one major peak that eluted in the position of decorin, a small chondroitin-dermatan sulfate proteoglycan. After digestion of the major peak with chondroitinase ABC, an approximately 45-kDa core protein was detected by Western blot analyses, confirming the presence of decorin. Form deprivation resulted in a significant reduction in the rate of proteoglycan synthesis in the posterior sclera (243.55%, P # 0.001). Proteoglycan synthesis was also significantly reduced in the posterior sclera of form-deprived eyes relative to total collagen content (236.19%, P # 0.01) and was negatively correlated with the rate of vitreous chamber elongation in the deprived eye (r 2 5 0.779, P # 0.05). CONCLUSIONS. Significant extracellular matrix remodeling occurs in the posterior sclera of the adolescent primate eye during vitreous chamber elongation and myopia development. The negative correlation between vitreous chamber elongation rates and the synthesis rates of decorin in form-deprived eyes suggests that proteoglycan synthesis within the posterior sclera plays a role in the regulation of ocular size and refraction in the adolescent marmoset. (Invest Ophthalmol Vis Sci. 2000;41:2050 ‐2058)
Deep Mycotic Infections

Systemic fungal disease (mycotic disease) is caused by several fungal organisms. These can infect several tissues however the lung is a major site of entry and infection. Infections are difficult to eradicate and are associated with considerable morbidity and even death. Immunocompromised individuals are more susceptible to fungal disease. Individuals living in an area endemic to certain fungi are also at greater risk. Extended drug therapy is required and involves the use of one or more antifungal drugs.
The effect of annealing on Ni–Al–Fe B2 compounds

Abstract Rods of both Ni–30Al–20Fe and Ni–40Al–30Fe were examined by optical microscopy and transmission electron microscopy in both the as-(double) extruded condition and after various heat treatments. Hardness, tensile and compression tests were performed on the alloys. The as-extruded and high temperature (750 °C or higher) microstructures of Ni–30Al–20Fe were similar and consisted of B2 grains with a γ-Fe phase covering some boundaries; at 500 °C the microstructure consists of α-Fe precipitates in a B2 matrix but no grain boundary phase was present. The microstructure of Ni–40Al–30Fe consisted of α-Fe precipitates in a B2 matrix at all temperatures, the precipitates coarsened with increasing annealing temperature. For short (200 min) anneals of both alloys yield strength, hardness maxima and ductility minima were found after annealing at 500 °C. These effects were ascribed to the α-Fe precipitates. The presence of the γ-Fe phase on the grain boundaries of Ni–30Al–20Fe may have contributed to the ductility enhancement in the as-extruded condition after high (750 °C or higher) anneals.
Caribbean octocorals record changing carbon and nitrogen sources from 1862 to 2005

During the last century the global biogeochemical cycles of carbon (C) and nitrogen (N) have been drastically altered by human activities. A century of land-clearing and biomass burning, followed by fossil fuel combustion have increased the concentration of atmospheric CO 2 by approximately 20%, and since the mid-1900s, the use of agricultural fertilizers has been the primary driver of an approximate 90% increase in bioavailable N. Geochemical records obtained through stable isotope analysis of terrestrial and marine biota effectively illustrate rising anthropogenic C inputs. However, there are fewer records of anthropogenic N, despite the enormous magnitude of change and the known negative effects of N on ecosystem health. We used stable isotope values from independent octocorals (gorgonians) sampled across the Western Atlantic over the last 143 years to document human perturbations of the marine C and N pools. Here, we demonstrate that in sea plumes δ 13 C values and in both sea plumes and sea fans δ 15 N values declined significantly from 1862 to 2005. Sea plume δ 13 C values were negatively correlated with increasing atmospheric CO 2 concentrations and corroborate known rates of change resulting from global fossil fuel combustion, known as the Suess effect. We suggest that widespread input of agricultural fertilizers to near-shore coastal waters is the dominant driver for the decreasing δ 15 N trend, though multiple anthropogenic sources are likely affecting this trend. Given the interest in using δ 15 N as an indicator for N pollution in aquatic systems, we highlight the risk of underestimating contributions of pollutants as a result of source mixing as demonstrated by a simple isotope-mixing model. We conclude that signals of major human-induced perturbations of the C and N pools are detectable in specimens collected over wide geographic scales, and that archived materials are invaluable for establishing baselines against which we can assess environmental change.
Multidimensional Signal Processing

The sections in this article are 1 Sampling Lattices 2 Multidimensional Sampled Signals 3 System Identification Problem 4 System Identification Examples 5 Conclusion
Construction of AC Motor Controllers for NOvA Experiment Upgrades

I have been constructing Alternating Current (AC) motor controllers for manipulation of particle beam detectors. The capability and reliability of these motor controllers are essential to the Laboratory's mission of accurate analysis of the particle beam's position. The device is moved in and out of the beam's path by the motor controller followed by the Neutrinos at the Main Injector Off-Axis {nu}{sub e} Appearance (NOvA) Experiment further down the beam pipe. In total, I built and tested ten ac motor controllers for new beam operations in the NOvA experiment. These units will prove to be durable and provide extremely accurate beam placement for NOvA Experiment far into the future.
Beyond Subsystems: Policy Regimes and Governance

We suggest attention to policy regimes provides a fruitful means for joining the contributions of scholars who study policy processes with those who are concerned with governance challenges. Our research synthesis underscores the limits of existing theorizing about policy processes for problems that span multiple areas of policy and highlights the prospects for and limitations of governing beyond the boundaries of subsystems. We suggest new avenues for theorizing and research in policy processes based on the concept of a boundary-spanning policy regime. We develop notions about this type of policy regime within the context of the broader literature about regimes in political science, discuss the forces that shape the strength and durability of such regimes, and provide a variety of examples. This synthesis challenges the focus of policy process scholars on subsystems and broadens the traditional focus on policymaking to consideration of the dynamics of governing.
Intelligent control of cupola furnaces

The objective of this research is to improve the efficiency of the cupola operation in the presence of desired output changes. This is achieved by developing an automatic controller for the cupola furnace. A controller was previously developed that provided tight control over the output parameters of the cupola under little or no desired change. The controller considers physical and practical limitations on the possible inputs. Previous research described optimal pairing of cupola outputs and inputs. This is exploited in a fuzzy controller that pairs oxygen enrichment and blast rate to the outputs of metal temperature and melt rate, respectively. The controller is modified to determine action when problems in production require a slow down or shut down of the melting process. A model is developed using a combination of experimental data and data obtained from the AFS cupola model. The model is a first order multivariable dynamical system. Due to the nonlinearities of the cupola, the model is only accurate for a narrow operating band. By varying the model parameters, simulations show the control to be robust. Simulations in the presence of input disturbances and output sensor noise show the controller efficiently rejects the common noise of a cupola furnace environment.
Leadership protocol for S-Nets

Smart sensor networks are collections of non-mobile devices (S-elements) which can compute, communicate and sense the environment; they must be able to create local groups of devices (S-clusters). We propose a protocol to solve the leadership problem for S-Nets. We sketch the correctness of this protocol in terms of an asynchronous network model.
FCS for characterizing nano-optical systems

Many groups have performed detailed calculations of the electromagnetic distribution near nanostructures for optical applications. Fluorescence correlation spectroscopy is a powerful experimental tool for validating these calculations and the effectiveness of nanostructures.
Toward Spoken Human–Computer Tutorial Dialogues

Oral discourse is the primary form of human–human communication, hence, computer interfaces that communicate via unstructured spoken dialogues will presumably provide a more efficient, meaningful, and naturalistic interaction experience. Within the context of learning environments, there are theoretical positions supporting a speech facilitation hypothesis that predicts that spoken tutorial dialogues will increase learning more than typed dialogues. We evaluated this hypothesis in an experiment where 24 participants learned computer literacy via a spoken and a typed conversation with AutoTutor, an intelligent tutoring system with conversational dialogues. The results indicated that (a) enhanced content coverage was achieved in the spoken condition; (b) learning gains for both modalities were on par and greater than a no-instruction control; (c) although speech recognition errors were unrelated to learning gains, they were linked to participants' evaluations of the tutor; (d) participants adjusted their co...
Acceptance of persuasion and the inhibition of counterargumentation under various distraction tasks

Abstract A discrepant communication was presented to subjects who monitored light flashes by visual, vocal, manual, or vocal-manual means. Higher rates of flashes increased acceptance of the communication and decreased counterargument production. Vocal and manual tasks were equally effective in inhibiting counterarguments and increasing acceptance, while the vocal-manual task was most effective in increasing acceptance of the counterattitudinal communication. The results suggest that the level and complexity of activity elicited by a distraction task is as important a determinant of persuasion-yielding and counterargument inhibition, as is the direct inhibition of the subvocal formation of counterarguments by distraction requiring vocal responding.
When Finance Leads Planning Urban Planning, Highway Planning, and Metropolitan Freeways in California

Freeways have profoundly influenced the form and function of U.S. cities, yet urban planners generally played only a peripheral role in their development. This article traces the history of freeway development in California to show how political negotiations between local and state governments over street and highway finance resulted in urban freeways financed, designed, and built by the state highway department. To fund their ambitious transportation plans, local officials and planners in cities like Los Angeles turned over control of the planning and development of urban freeways in the 1940s and 1950s to state departments of transportation. This shift in control led to, among other things, the construction of freeways too large to fit easily into cities and freeway networks too sparse to adequately disperse urban traffic. While federal surface transportation legislation returned significant control over metropolitan freeways to regions and planners in the 1990s, the influence of modern freeways on urban life endures.
Linear Adaptive Control via Disturbance-Accommodation; Some Case Studies

In [1], [2], [3] an essentially new approach to adaptive control was developed, using the principles and tools of disturbance-accommodating control (DAC) theory. This new approach to adaptive control design is unique in that the resulting adaptive controller is entirely linear and, for the case of "stationary" plants, has all constant parameters. In the present paper, the DAC adaptive control theory developed in [1]-[3] is applied to several specific examples (case-studies) and the resulting closed-loop adaptive systems are exercised on computer simulations to demonstrate the level of adaptive performance achieved. The latter results are somewhat striking and suggest that this new all-linear approach to adaptive controller design is a major advance in modern linear system theory.
III.—The Ventral Integument of Trilobites

In previous papers by the writer on the structure and appendages of Triarthrus , no attempt has been made to describe or illustrate the character of the ventral integument, especially in the sternal or axial region. The specimens hitherto described were prepared to show details of the appendages, and though portions of the ventral membrane were exposed in many individuals, the subject was not considered of sufficient moment to warrant a distinct study, particularly as no characters were observed in the cuticle that had not been previously seen in more or less perfection by Walcott in the genera Ceraurus and Calymene . A recent discovery by Jaekel, however, necessitates the separate consideration of this structure. This necessity arises from the fact that a positive addition to the knowledge of the trilobite anatomy may be deduced, although, as will be shown, Jaekel was apparently entirely misled in his interpretation of the nature of his discovery.
Understanding Availability: Usability Testing of a Consortial Interlibrary Loan Catalog

In 2009, the Technology Development Team at the New York-based Information Delivery Services (IDS) Project created IDS Search, a consortial catalog that promoted the group's collection and interlibrary loan features equally with the local collection and local availability. Because the success of IDS Search relied heavily on users fully understanding the different types of availability, the authors conducted usability studies to investigate how well users could determine how to locate materials and understand the availability of items. Eye-tracking analysis was used to determine how well users understood availability, related text, and meanings of terms. The studies found that users had difficulty navigating the functions of the online public access catalog (OPAC) and could not easily differentiate among items that were immediately available, available in a few days, or available online as a preview.
Infection, systemic inflammation, and Alzheimer's disease

Alzheimer's disease (AD) is a leading cause of dementia among elderly. Yet, its etiology remains largely unclear. In this review, we summarize studies that associate systemic infection and neuroinflammation with AD, while highlighting that early-life or life-long exposure to infectious agents predisposes one to develop AD at a later age.
Keynote lecture: CACSD Tools - A MathWorks perspective

Software tools are playing an increasingly central role in the adoption and dissemination of CACSD techniques throughout academia and industry. As a leading provider of such tools for the past 20 years, MathWorks has been actively involved in shaping and facilitating the software revolution in control systems engineering.
In vitro evaluation of CSF shunt function by radionuclides

An in vitro study of clearance of a radiolabeled marker was conducted on nine commonly used shunting devices. Clearance of 0.5 ml of113mIn-diethylenetriamine-pentaacetic acid (DTPA) injected into the chamber, by water infused through the system at constant rate (0.034–0.46 ml/min), was measured by monitoring activity over the chamber and accumulating counts at 5-s intervals on a multichannel analyzer. Each flow rate was triplicated, and a graph of log value of counts versus time made. A mean t1/2 was computed for each flow rate and a new graph constructed. A best-fit curve constructed for the graph of each shunt system allows determination of flow rate for a known half time of isotope clearance.
A synaptic mechanism for network synchrony.

Within neural networks, synchronization of activity is dependent upon the synaptic connectivity of embedded microcircuits and the intrinsic membrane properties of their constituent neurons. Synaptic integration, dendritic Ca2+ signaling, and non-linear interactions are crucial cellular attributes that dictate single neuron computation, but their roles promoting synchrony and the generation of network oscillations are not well understood, especially within the context of a defined behavior. In this regard, the lamprey spinal central pattern generator stands out as a well-characterized, conserved vertebrate model of a neural network (Smith et al., 2013a), which produces synchronized oscillations in which neural elements from the systems to cellular level that control rhythmic locomotion have been determined. We review the current evidence for the synaptic basis of oscillation generation with a particular emphasis on the linkage between synaptic communication and its cellular coupling to membrane processes that control oscillatory behavior of neurons within the locomotor network. We seek to relate dendritic function found in many vertebrate systems to the accessible lamprey central nervous system in which the relationship between neural network activity and behavior is well understood. This enables us to address how Ca2+ signaling in spinal neuron dendrites orchestrate oscillations that drive network behavior.
Bijective Collection Encodings and Boolean Operations with Hereditarily Binary Natural Numbers

Our tree-based hereditarily binary numbers apply recursively a run-length compression mechanism. They enable performing arithmetic computations symbolically and lift tractability of computations to be limited by the representation size of their operands rather than by their bitsizes.We apply them to derive compact representations for "structurally simple" (sparse or dense) lists, sets and multisets, as well as their hereditarily finite counterparts. This enables the use of hereditarily binary numbers to define bijective size-proportionate Godel numberings for several data types, that we "virtualize" through a generic data type transformation framework. As an application, a size-proportionate Godel numbering scheme for term algebras is derived.After extending the arithmetic operations on hereditarily binary numbers with boolean operations, we use them to perform computations with bitvectors and sets as well as a 3-valued logic interpretation for bijective base-2 bitvectors.
Synthesis of nitrogen-bridged purine-like C-nucleosides from ethyl 2,5-anhydro-6-O-benzoyl-d-allonodithioate

Abstract Ethyl 2,5-anhydro-6- O -benzoyl- d -allonodithioate ( 1 ) was coupled with aminomethyl- and hydrazino-azines to afford the title compounds. Specifically, 1 was coupled with 2-(aminomethyl)pyridine to afford 3-β- d -ribofuranosylimidazolo-[1,5- a ]pyridine, with 2-hydrazinopyrazine to yield 3-β- d -ribofuranosyl-1,2,4-triazolo[4,3- a ]pyrazine, and with 2-hydrazinopyrimidine to form a 3-substituted 1,2,4-triazolo[4,3- a ]pyrimidine which underwent a Dimroth rearrangement to yield 2-β- d -ribofuranosyl-1,2,4-triazolo[1,5- a ]pyrimidine. Finally, compound 1 was coupled with 2-hydrazino-4-hydroxy-6-methylpyrimidine to yield 7-methyl-3-β- d -ribofuranosyl- 1,2,4-triazolo[4,3- a ]-5(8 H )-pyrimidone.
Cold hardiness in the scorpion, Paruroctonus aquilonalis

Abstract Lower lethal temperatures represented by supercooling points were measured for the scorpion Paruroctonus aquilonalis (Stahnke) following exposure to laboratory regimes of photoperiod and temperature, as well as to ambient conditions. Analyses for the presence of glycerol and sorbitol in hemolymph, and of body water content were also performed. Laboratory results indicated that neither decreasing photoperiod nor decreasing temperature influenced supercooling point in a meaningful way. However, supercooling points did decrease significantly during the fall and winter among scorpions maintained outdoors, indicating development of cold hardiness. Neither glycerol nor sorbitol were detected, nor were the slight seasonal decreases found in water content considered sufficient to influence supercooling point. Ability to avoid winter freezing in P. aquilonalis appears primarily conferred by substantial seasonal depression of the supercooling point and is temporally associated with cessation of feeding in the fall. Supercooling responses were compared with those of another scorpion, Diplocentrus spitzeri , and differences tentatively were explained in terms of feeding activity.
Persistence of spinocerebellar afferent topography following hereditary Purkinje cell degeneration.

Cerebellar Purkinje neurons play a significant role in the development and early maintenance of cerebellar afferent topography. Anterograde intraaxonal labeling experiments were designed to identify any role for Purkinje cells in maintaining spinocerebellar mossy fiber afferent topography in shaker mutant rats with adult onset Purkinje cell heredodegeneration. Following the death of Purkinje cells myelinated spinocerebellar axons persist and their terminal mossy fiber morphology remains normal in appearance and size. The relative percentage of labeled projections to each of the five anterior lobe lobules was comparable in mutant and normal rats. Finally, unfolded reconstructions of the anterior lobe illustrated that the organization of labeled terminals in clusters, patches and discontinuous parasagittally oriented stripes or transversely oriented bands were spatially distributed the same in both normal and mutant rats. These findings strongly infer that Purkinje cells are not necessary for the persistence and maintenance of spinocerebellar afferent pathways in adult animals.
Strontium and oxygen isotopic evidence for strike/slip movement of accreted terranes in the Idaho Batholith

Abstract The oxygen and strontium isotope compositions of granitic rocks of the Idaho Batholith provide insight into the magma source, assimilation processes, and nature of the suture zone between the Precambrian craton and accreted arc terranes. Granitic rocks of the Idaho Batholith intrude basement rocks of different age: Triassic/Jurassic accreted terranes to the west of the Salmon River suture zone and the Precambrian craton to the east. The age difference in the host rocks is reflected in the abrupt increase in the initial 87 Sr/ 86 Sr ratios of granitic rocks in the batholith across the previously defined 0.706 line. Initial 87 Sr/ 86 Sr ratios of granitic rocks along Slate Creek on the western edge of the batholith jump from less than 0.704 to greater than 0.707 along an approximately 700 m transect normal to the Salmon River suture. Initial 87 Sr/ 86 Sr ratios along the Slate Creek transect do not identify a transition zone between accreted arcs and the craton and suggest a unique tectonic history during or after suturing that is not documented along other transects on the west side of the Idaho Batholith. The lack of transition zone along Slate Creek may be a primary structure due to transcurrent/transpressional movement rather than by contractional thrust faulting during suturing or be the result of post-imbrication modification.
Effects of controlled surface treatment on titanium dioxide electrode nanostructure for dye-sensitized solar cells

A stable surface treatment for the nanoporous TiO2 electrode of dye-sensitized solar cells (DSCs) has been developed via sol-gel processing of titanium(IV) isopropoxide (TiP), enabling controllable performance improvements, which has been hitherto unachievable. A systematic study of the electrode chemistry and morphology was performed to examine the mechanisms by which the treatment contributes to enhancement in DSC performance. The electrode exhibited a linear increase in mass with TiP concentration and a corresponding reduction in porosity. The increase in nanoparticle diameter resulted in the increase in surface area without altering the surface chemistry, leading to an increase in dye loading. Current–voltage characteristics and incident photon-to-electron conversion efficiencies (IPCE) were analyzed. A linear increase in the short-circuit photocurrent was measured with TiP concentration, increasing by 30 % for a 4 mM TiP treatment, which resulted in a corresponding efficiency gain of 23 %. This was found to primarily result from a controllable increase in the charge collection efficiency, via a 30 % faster electron transport time and a 19 % increase in the electron lifetime. The results elucidate the underlying physical mechanisms for improvement in DSC performance by surface treatment.
Mapping the structural and dynamical features of kinesin motor domains.

Kinesin motor proteins drive intracellular transport by coupling ATP hydrolysis to conformational changes that mediate directed movement along microtubules. Characterizing these distinct conformations and their interconversion mechanism is essential to determining an atomic-level model of kinesin action. Here we report a comprehensive principal component analysis of 114 experimental structures along with the results of conventional and accelerated molecular dynamics simulations that together map the structural dynamics of the kinesin motor domain. All experimental structures were found to reside in one of three distinct conformational clusters (ATP-like, ADP-like and Eg5 inhibitor-bound). These groups differ in the orientation of key functional elements, most notably the microtubule binding α4–α5, loop8 subdomain and α2b-β4-β6-β7 motor domain tip. Group membership was found not to correlate with the nature of the bound nucleotide in a given structure. However, groupings were coincident with distinct neck-linker orientations. Accelerated molecular dynamics simulations of ATP, ADP and nucleotide free Eg5 indicate that all three nucleotide states could sample the major crystallographically observed conformations. Differences in the dynamic coupling of distal sites were also evident. In multiple ATP bound simulations, the neck-linker, loop8 and the α4–α5 subdomain display correlated motions that are absent in ADP bound simulations. Further dissection of these couplings provides evidence for a network of dynamic communication between the active site, microtubule-binding interface and neck-linker via loop7 and loop13. Additional simulations indicate that the mutations G325A and G326A in loop13 reduce the flexibility of these regions and disrupt their couplings. Our combined results indicate that the reported ATP and ADP-like conformations of kinesin are intrinsically accessible regardless of nucleotide state and support a model where neck-linker docking leads to a tighter coupling of the microtubule and nucleotide binding regions. Furthermore, simulations highlight sites critical for large-scale conformational changes and the allosteric coupling between distal functional sites.
Chronic corticosterone administration does not potentiate unconditioned freezing to the predator odor, trimethylthiazoline.

Abstract Chronic high levels of corticosterone (CORT) are known to facilitate learning and memory of aversive events. Whether this effect of chronic CORT also generalizes to unconditioned or unlearned fear behavior is not known. The present study investigated whether high levels of chronic CORT enhance unconditioned fear to a predator odor, trimethylthiazoline (TMT), an innate fear stimulus to rodents. TMT induces a dose-related freezing response, a prototypical behavior to fearful stimuli, in rats. The first experiment demonstrated that dose-related freezing to repeated exposures of TMT does not habituate, sensitize or produce contextually conditioned fear, and therefore can be used to measure the effects of chronic CORT on unconditioned fear to repeated exposures of TMT. In Experiment 2, 21-day release corticosterone pellets (200 mg) were implanted subcutaneously in male, Sprague–Dawley rats. Control rats received sham implantation. On days when TMT was not present, chronic CORT rats froze significantly more than sham rats. However, while TMT-induced freezing in both chronic CORT and sham rats, freezing during exposure to TMT was not further enhanced in chronic CORT rats. Thus, chronic CORT appears to increase fear as measured by freezing, possibly by enhancing vigilance, but does not facilitate fear behavior induced by the innate fear stimulus, TMT.
Activation of the yeast Arp2/3 complex by Bee1p, a WASP-family protein.

Abstract The Arp2/3 complex is a highly conserved cytoskeletal component that has been implicated in the nucleation of actin filament assembly [1]. Purified Arp2/3 complex has a low intrinsic actin nucleation activity, leading to the hypothesis that an unidentified cellular activator is required for the function of this complex [2 3]. We showed previously that mutations in the Arp2/3 complex and in Bee1p/Las17p, a member of the Wiskott–Aldrich syndrome protein(WASP) family, lead to a loss of cortical actin structures (patches) in yeast [4 5]. Bee1p has also been identified as an essential nucleation factor in the reconstitution of actin patches in vitro [6]. Recently, it was reported that WASP-like proteins might interact directly with the Arp2/3 complex through a conserved carboxy-terminal domain [7]. Here, we have shown that Bee1p and the Arp2/3 complex co-immunoprecipitate when expressed at endogenous levels, and that this interaction requires both the Arc15p and Arc19p subunits of the Arp2/3 complex. Furthermore, the carboxy-terminal domain of Bee1p greatly stimulated the nucleation activity of purified Arp2/3 complex in vitro , suggesting a direct role for WASP-family proteins in the activation of the Arp2/3 complex. Interestingly, deletion of the carboxy-terminal domain of Bee1p neither abolished the localization of the Arp2/3 complex, as had been suggested, nor resulted in a severe defect in cortical actin assembly. These results indicate that the function of Bee1p is not mediated entirely through its interaction with the Arp2/3 complex, and that factors redundant with Bee1p might exist to activate the nucleation activity of the Arp2/3 complex.
Acetylcholine receptors on chick mononucleated muscle precursor cells

Abstract Most mononucleated muscle precursor cells in 11-day embryonic chick pectoral muscles possess acetylcholine receptors. Cells dissociated without the use of proteolytic enzymes were exposed to 125 I-labeled α-bungarotoxin and specific binding was determined by a filter assay and by autoradiography. Prior incubation with proteolytic enzymes removed nearly all of the specific toxin binding sites. There was a wide range in receptor number per cell within the population of 11-day cells. Cells dissociated from 7- to 8-day embryos bind less toxin than 11-day cells. This reflects a decrease in receptor number per cell rather than a decrease in the percentage of labeled cells. Reasons why acetylcholine receptors have not been detected on the majority of muscle precursor cells in previous studies are offered and it is suggested that the appearance of receptors may be an early sign of commitment to a myogenic lineage.
Introduction: discontinuity – a weakness of calculus and beginning of a new era

In this article, the historical victories and shortfalls of calculus and calculus‐based methods are briefly described so that a need of developing the theory of blown‐ups is given. Listed are several challenges of the theory of blown‐ups to the traditional thinking logic of continuity and characteristics of the theory of blown‐ups.
The coastal longshore pressure gradient: Temporal variations and driving mechanisms

Along the northern coastal boundary of the Mid-Atlantic Bight, synthetic subsurface pressure records derived from 1975 tide gage and airway weather observations are examined for fluctuations having monthly time scales. Additional calculations are performed to determine the factors controlling variance in these pressure data. Similar analyses are applied to the longshore gradient in synthetic subsurface pressure. Results of the study indicate that synthetic subsurface pressures are controlled by three mechanisms, two each at either end of the coastal segment. Fluctuations in Gulf Stream position have a significant effect on monthly mean pressures, which are uniform along the coast. At the western end of the coastal segment, east-west winds are also important, while changes in water density contribute significantly to subsurface pressure variance at the eastern end. Coastal steric differences are found to be a minor contributor to monthly fluctuations of longshore pressure gradient, while the coastal mean east-west winds effect a linear response in the gradient. Using this relationship and upon removal of geodetic leveling errors, the annual mean longshore sea surface slope is calculated to be 1.6×10−7, forming a westward pressure gradient along the northern boundary of the Mid-Atlantic Bight.
Analysis of a novel bedded planting system for dry clay soil management of full-season and double-crop soybean

Clay soils are difficult to manage to obtain a soybean [Glycine max (L.) Merr.] stand, especially when dry. A novel production system, recently observed on several farms in Arkansas, consists of bedding the dry clayey soil with disk‐bedders, broadcasting the soybean seed over the surface, re‐bedding the seedbed to cover the seed, rolling the beds to flatten the tops and finally furrow irrigating immediately thereafter. Typically this planting system provides a stand of soybean within 4 to 6 days after irrigation and is designated as “hipped” after the common reference of a disk‐bedder as a hipper. Studies were conducted on Sharkey soil at Keiser, AR from 1998 to 2000 for comparing this “hipped” system to more widely used planting methods. On dry clayey soils, a randomized complete block design with three replications was used to compare full‐season soybean under a conventional 96‐cm row system, drilled‐planting into a stale seedbed, and the “hipped” system. A similar study for double‐cropped wheat‐soybean...
The glycoprotein nature and antigenicity of a fungal D-glucosyltransferase.

Abstract d -Glucosyltransferase (EC 2.4.1.24) from Aspergillus niger has been prepared in pure form by chromatography on DEAE-cellulose. The enzyme transfers d -glucosyl units from maltose and other α-linked d -glucosyl oligosaccharides to glucosyl co-substrates resulting in the synthesis of new types of oligosaccharides. The glucosyltransferase has been found to be a glycoprotein containing 20% of carbohydrate consisting of mannose, glucose, and galactose. The carbohydrate residues are attached as either single units or as short oligosaccharide chains by O-glycosyl linkages to the serine and threonine residues of the protein. Antibodies directed against glucosyltransferase have been induced in animals by appropriate immunization regimes. These antibodies combine with the carbohydrate components of the enzyme and, therefore, the carbohydrate residues are the immunodeterminant groups of the glucosyltransferase.
Responsibility to Punish: Discouraging Free-Riders in Public Goods Games

This study employs a public goods game in which participants can punish each other for free-riding. This paper examines the motivation for punishment behavior when the situation is such that a rational individual will not punish. This paper predicts and finds evidence for the punishment of free-ridership, even when not punishing is the profit-maximizing strategy. Specifically, this paper finds participants will punish more when designated the sole punisher for a group, than when all group members are allowed to punish. This result implies that those individuals who punish for non-rational reasons often free-ride on each others’ punishment. Accordingly, the study suggests individual responsibility is important for ensuring the strength of institutions aimed at punishing selfish behavior.