cssi/SciSciGPT-SciSciNet huggingface dataset:
Metrology of the Real Nanoclusters: Structure and Optical Characteristics

In this paper, we have discussed in detail the electronic structure and optical characteristics of the silicon nanoclusters. One of the main conclusions is that the comparison between theoretical calculations and experimental results are correct. We shows the possibility of different radiative channels for the recombination in porous silicon. We now analyze the case of stronger disorder as obtained in amorphous silicon (a-Si). It raises extremely interesting problems related to the confinement-induced blue shift of the energy gap: (a) does it exist in nanoclusters of a-Si and is it comparable to what is obtained for c-Si; (b) what is the behavior of disorder-induced localized states in this regard. It has been often assumed that quantum confinement’s effects are small in a-Si nanostructures due to the short coherence length of free carriers in these materials. We will see that it is not true. We calculate the electronic structure of a-Si and a-Si:H spherical clusters using the parametrized density functional theory (PDFT) model [1]. The starting structure for the a-Si or a-Si: H nanoclusters is obtained by selecting the atoms belonging to the respective atoms unit cell. Due to the new boundary conditions the structure is no more in equilibrium and we have thus relaxed the atomic positions using a Keating potential.
Copper-Catalyzed 1,2-Aminocyanation of Unactivated Alkenes via Cyano Migration

A copper-catalyzed aminocyanation of alkenes has been achieved through distal cyano migration using O-benzoylhydroxylamines and N-fluorobenzenesulfonimides. This method offers a rapid approach to g...
Cost-Effectiveness Analysis of Immediate Access Arteriovenous Grafts Versus Standard Grafts for Hemodialysis

Abstract Objective Immediate-access arteriovenous grafts (IAAVGs), or early cannulation arteriovenous grafts (AVGs), are more expensive than standard grafts (sAVGs) but can be used immediately after placement, reducing the need for a tunneled dialysis catheter (TDC). We hypothesized that a decrease in TDC-related complications would make IAAVGs a cost-effective alternative to sAVGs. Methods We constructed a Markov state-transition model in which patients initially received either an IAAVG or an sAVG and a TDC until graft usability; patients were followed through multiple subsequent access procedures for a 60-month time horizon. The model simulated mortality and typical graft- and TDC-related complications, with parameter estimates including probabilities, costs, and utilities derived from previous literature. A key parameter was median time to TDC removal after graft placement, which was studied under both real-world (7 days for IAAVG and 70 days for sAVG) and ideal (no TDC placed with IAAVG and 1 month for sAVG) conditions. Costs were based on current Medicare reimbursement rates and reflect a payer perspective. Both microsimulation (10,000 trials) and probabilistic sensitivity analysis (10,000 samples) were performed. The willingness-to-pay threshold was set at $100,000 per quality-adjusted life-year (QALY). Results IAAVG placement is a dominant strategy under both real-world ($1201.16 less expensive and 0.03 QALY more effective) and ideal ($1457.97 less expensive and 0.03 QALY more effective) conditions. Under real-world parameters, the result was most sensitive to the time to TDC removal; IAAVGs are cost-effective if a TDC is maintained for ≥23 days after sAVG placement. The mean catheter time was lower with IAAVG (3.9 vs 8.7 months; P Conclusions The Markov decision analysis model supported our hypothesis that IAAVGs come with added initial cost but are ultimately cost-saving and more effective. This apparent benefit is due to our prediction that a decreased number of catheter days per patient would lead to a decreased number of access-related infections.
Geospatial simulation steering for adaptive management

Abstract Spatio-temporal simulations are becoming essential tools for decision makers when forecasting future conditions and evaluating effectiveness of alternative decision scenarios. However, lack of interactive steering capabilities limits the value of advanced stochastic simulations for research and practice. To address this gap we identified conceptual challenges associated with steering stochastic, spatio-temporal simulations and developed solutions that better represent the realities of decision-making by allowing both reactive and proactive, spatially-explicit interventions. We present our approach, in a participatory modeling case study engaging stakeholders in developing strategies to contain the spread of a tree disease in Oregon, USA. Using intuitive interfaces, implemented through web-based and tangible platforms, stakeholders explored management options as the simulation progressed. Spatio-temporal steering allowed them to combine currently used management practices into novel adaptive management strategies, which were previously difficult to test and assess, demonstrating the utility of interactive simulations for decision-making.
Discrepancies in Local, State, and National Alcohol Outlet Listings: Implications for Research and Interventions

The availability of local, state, and national data on alcohol outlet density have important implications for policies and interventions aiming to reduce alcohol-related problems. High-quality data...
Fabrication and characterization of a thick, viable bi-layered stem cell-derived surrogate for future myocardial tissue regeneration.

Cardiac tissue surrogates show promise for restoring mechanical and electrical function in infarcted left ventricular (LV) myocardium. For these cardiac surrogates to be useful in vivo, they are required to support synchronous and forceful contraction over the infarcted region. These design requirements necessitate a thickness sufficient to produce a useful contractile force, an area large enough to cover an infarcted region, and prevascularization to overcome diffusion limitations. Attempts to meet these requirements have been hampered by diffusion limits of oxygen and nutrients (100-200 μm) leading to necrotic regions.This study demonstrates a novel layer-by-layer (LbL) fabrication method used to produce tissue surrogates that meet these requirements and mimic normal myocardium in form and function. Thick (1.5-2 mm) LbL cardiac tissues created from human induced pluripotent stem cell-derived cardiomyocytes and endothelial cells were assessed, in vitro, over a four week period for viability (< 5.6 ± 1.4 % nectrotic cells), cell morphology, viscoelastic properties and functionality. Viscoelastic properties of the cardiac surrogates were determined via stress relaxation response modeling and compared to native murine LV tissue. Viscoelastic characterization showed that the generalized Maxwell model of order 4 described the samples well (0.7 < R2 < 0.98). Functional performance assessment showed enhanced t-tubule network development, gap junction communication as well as conduction velocity (16.9 ± 2.3 cm s-1). These results demonstrate that LbL fabrication can be utilized successfully in creating complex, functional cardiac surrogates for therapeutic applications.
A comprehensive data-driven analysis framework for detecting impairments in brain function networks with resting state fMRI in HIV-infected individuals on cART.

Central nervous system (CNS) sequelae continue to be common in HIV-infected individuals despite combination antiretroviral therapy (cART). These sequelae include HIV-associated neurocognitive disorder (HAND) and virologic persistence in the CNS. Resting state functional magnetic resonance imaging (rsfMRI) is a widely used tool to examine the integrity of brain function and pathology. In this study, we examined 16 HIV-positive (HIV+) subjects and 12 age, sex, and race matched HIV seronegative controls (HIV−) whole-brain high-resolution rsfMRI along with a battery of neurocognitive tests. A comprehensive data-driven analysis of rsfMRI revealed impaired functional connectivity, with very large effect sizes in executive function, language, and multisensory processing networks in HIV+ subjects. These results indicate the potential of high-resolution rsfMRI in combination with advanced data analysis techniques to yield biomarkers of neural impairment in HIV.
Assessing seizure burden in pediatric epilepsy using an electronic medical record-based tool through a common data element approach.

Objective Improvement in epilepsy care requires standardized methods to assess disease severity. We report the results of implementing common data elements (CDEs) to document epilepsy history data in the electronic medical record (EMR) after 12 months of clinical use in outpatient encounters. Methods Data regarding seizure frequency were collected during routine clinical encounters using a CDE-based form within our EMR. We extracted CDE data from the EMR and developed measurements for seizure severity and seizure improvement scores. Seizure burden and improvement was evaluated by patient demographic and encounter variables for in-person and telemedicine encounters. Results We assessed a total of 1696 encounters in 1038 individuals with childhood epilepsies between September 6, 2019 and September 11, 2020 contributed by 32 distinct providers. Childhood absence epilepsy (n = 121), Lennox-Gastaut syndrome (n = 86), and Dravet syndrome (n = 42) were the most common epilepsy syndromes. Overall, 43% (737/1696) of individuals had at least monthly seizures, 17% (296/1696) had a least daily seizures, and 18% (311/1696) were seizure-free for >12 months. Quantification of absolute seizure burden and changes in seizure burden over time differed between epilepsy syndromes, including high and persistent seizure burden in patients with Lennox-Gastaut syndrome. Individuals seen via telemedicine or in-person encounters had comparable seizure frequencies. Individuals identifying as Hispanic/Latino, particularly from postal codes with lower median household incomes, were more likely to have ongoing seizures that worsened over time. Significance Standardized documentation of clinical data in childhood epilepsies through CDE can be implemented in routine clinical care at scale and enables assessment of disease burden, including characterization of seizure burden over time. Our data provide insights into heterogeneous patterns of seizure control in common pediatric epilepsy syndromes and will inform future initiatives focusing on patient-centered outcomes in childhood epilepsies, including the impact of telemedicine and health care disparities.
Surface topography as a tool to detect early changes in a posttraumatic equine model of osteoarthritis

The equine model of posttraumatic osteoarthritis (OA) mimics certain aspects of the naturally occurring disease, both in horses and humans. The objective of this study was to assess articular cartilage degeneration in a posttraumatic OA model using the established macroscopic and microscopic scoring systems and compare them with a novel surface topography analysis. OA was induced in the carpal joint of 15 (n = 15) mixed breed horses. Surface changes on the articular cartilage were characterized using osteochondral blocks from the third carpal bone (C3) and radial carpal bone using surface topography, standard histological grading, and gross evaluation of the joints. Significant differences were observed between OA and non-OA joints for gross evaluation scores. Microscopic scores of hematoxylin and eosin and Safranin O and Fast Green-stained sections demonstrated no differences between OA and non-OA joints. However, articular cartilage from the induced OA joint had significantly greater surface topography measurements compared with the sham treatment group, consistent with the changes seen on gross evaluation of joints. No significant correlations were noted between surface roughness measurements, histological assessment, and gross evaluation scores. The results suggest that surface topography analysis may provide a reliable objective approach to assess early changes in the cartilage surface in OA.
Differences in tumor sequencing across ethnic groups in the treatment of endometrial cancer

Objectives: We aimed to identify ethnic differences in genetic mutations associated endometrial cancer (EC), as well as differences in the utilization of sequencing results to direct disease treatment based on actionable mutations among different ethnic groups. Methods: Patients of interest were identified using the EMERSE program. Inclusion criteria included patients with endometrial cancer who underwent solid tumor genomic sequencing between the dates of April 2014 and January 2019 at our institution. Patients meeting the inclusion criteria with verifiable tumor sequencing results were included in our retrospective cohort. Patients were excluded if they had synchronous cancers and germline or non-solid tumor testing only. Clinical information was abstracted from the medical record. Differences between groups were calculated using descriptive statistics. Results: 287 patients met inclusion criteria. The majority of patients who underwent genomic sequencing of their tumors were non-Hispanic Caucasian (n=212, 73.9%), followed by non-Hispanic African American (n=55, 19.2%) and Hispanic (n=6, 2.1%), a distribution that accurately reflects the ethnic makeup of our state population. Among patients who underwent tumor sequencing, non-Hispanic Caucasian patients had an 82% likelihood (n=174) of having an actionable mutation, whereas non-Hispanic African American patients had a 60% likelihood (n=33) (p Conclusions: Genomic sequencing of solid tumors was utilized in a high percentage of patients with endometrial cancer. When examining ethnic groups, no disparate use of tumor sequencing was found. Similar actionable mutations were seen across ethnic groups when controlling for tumor histology. Overall, utilization of tumor sequencing results to personalize care was used at a low rate among patients with actionable mutations across ethnic groups. This underutilization highlights the need for the continued development of efficacious, targeted therapies for endometrial cancer.
Modeling the Dividend Process When Leverage Ratios are Stationary

Models that attempt to explain the 'equity premium puzzle' (e.g., Campbell and Cochrane (1999), Bansal and Yaron (2004)) often assume that dividend flows are locally deterministic (i.e., are of the form (C(t) dt) in the continuous time limit) and that the growth rate of consumption g_{c} and dividends g_{d} are the same. However, such an approach seems to conflict with interpreting dividends as leveraged cash flows, and hence as having a higher growth rate. We resolve this apparent paradox by investigating a firm which rebalances its debt levels over time to maintain a stationary leverage process. In doing so, managers reduce (increase) the level of shareholder investment by issuing (repurchasing) debt. In the continuously rebalancing limit, dividends have two components: a locally deterministic part related to (EBIT minus interest), and a stochastic part due to debt issuances/repurchases. The model generates a functional form for firm value that is identical to that obtained in a Gordon growth model. However, the stock return volatility is greater than that implied by the Gordon growth model. We then show that if one wishes to specify the form of the dividend process as in CC and BY, then one needs to consider an agent who re-invests that part of the dividend that is due to debt issuances back into the stock (and vice-versa for debt repurchases). This portfolio strategy generates a higher expected growth rate for dividends than for EBIT.
A compact high-power proton linac for radioisotope production

Conventional designs for proton linacs use a radio-frequency quadrupole (RFQ), followed by a drift-tube linac (DTL). For higher final beam energies, a coupled cavity linac (CCL) follows the DTL. A new structure, the coupled-cavity drift-tube linac (CCDTL) combines features of an Alvarez DTL and the CCL. Operating in a /spl pi//2 structure mode, the CCDTL replaces the DTL and part of the CCL for particle velocities in the range 0.1/spl les//spl beta//spl les/0.5. We present a design concept for a compact linac using only an RFQ and a CCDTL. This machine delivers a few mA of average beam current at a nominal energy of 70 MeV and is well suited for radioisotope production.
The Carboxylation of Phosphoenolpyruvate and Pyruvate II. THE ACTIVE SPECIES OF "CO2" UTILIZED BY PHOSPHOENOLPYRUVATE CARBOXYLASE AND PYRUVATE CARBOXYLASE

Abstract The active species of "CO2," i.e. CO2 or HCO3-, utilized in the pyruvate carboxylase and phosphoenolypruvate carboxylase reaction have been determined with an assay predicated upon the fact that the hydration of CO2 is a kinetically slow and measurable reaction. The results of these assays in both cases are in reasonable agreement with those expected if HCO3- is assumed to be the functional species utilized by both enzymes.
Teachers in North Carolina's Environmental Education Certification Program

This article describes the North Carolina Environmental Education (EE) Certification Program, which was established in 1997, and examines the certification experiences of the kindergarten through 12th grade teachers who have completed the program. Because this program is central to describing and assessing the status of K-12 environmental education in North Carolina, the authors make some policy suggestions to encourage a more focused, more intense, more aligned approach to education for the environment.
Sustainable, reliable and cost effective solutions in plastic components for electric and electronic industry

Is it possible to keep functionality of Electrical and Electronic components and preserve environment? Can we maintain performance and durability by using high performance materials from renewable resources instead of petroleum? How can Electric and Electronic industry be sustainable and keep cost effectiveness?
VHHC in Helicopters

Higher Harmonic Control (HHC) is a method for cancelling the helicopter fuselage vibrations by introducing N/rev oscillations of rotor blades pitch angle (N is the number of rotor blades). This method is effective if both the amplitude and the phase of the oscillations introduced are chosen appropriately, depending on the flight conditions. It is shown in this paper that if the frequency of these oscillations is much greater than N/rev, the phase dependency disappears.
The Anatomical and Functional Organization of the Human Visual Pulvinar.

The pulvinar is the largest nucleus in the primate thalamus and contains extensive, reciprocal connections with visual cortex. Although the anatomical and functional organization of the pulvinar has been extensively studied in old and new world monkeys, little is known about the organization of the human pulvinar. Using high-resolution functional magnetic resonance imaging at 3 T, we identified two visual field maps within the ventral pulvinar, referred to as vPul1 and vPul2. Both maps contain an inversion of contralateral visual space with the upper visual field represented ventrally and the lower visual field represented dorsally. vPul1 and vPul2 border each other at the vertical meridian and share a representation of foveal space with iso-eccentricity lines extending across areal borders. Additional, coarse representations of contralateral visual space were identified within ventral medial and dorsal lateral portions of the pulvinar. Connectivity analyses on functional and diffusion imaging data revealed a strong distinction in thalamocortical connectivity between the dorsal and ventral pulvinar. The two maps in the ventral pulvinar were most strongly connected with early and extrastriate visual areas. Given the shared eccentricity representation and similarity in cortical connectivity, we propose that these two maps form a distinct visual field map cluster and perform related functions. The dorsal pulvinar was most strongly connected with parietal and frontal areas. The functional and anatomical organization observed within the human pulvinar was similar to the organization of the pulvinar in other primate species. SIGNIFICANCE STATEMENT The anatomical organization and basic response properties of the visual pulvinar have been extensively studied in nonhuman primates. Yet, relatively little is known about the functional and anatomical organization of the human pulvinar. Using neuroimaging, we found multiple representations of visual space within the ventral human pulvinar and extensive topographically organized connectivity with visual cortex. This organization is similar to other nonhuman primates and provides additional support that the general organization of the pulvinar is consistent across the primate phylogenetic tree. These results suggest that the human pulvinar, like other primates, is well positioned to regulate corticocortical communication.
Empowering Students to Create and Claim Value through the Thomas–Kilmann Conflict Mode Instrument

In a world of problem-solving lawyering, principled negotiation, and integrative bargaining, to describe a negotiation as “distributional” may strike some as heretical. Still, we disserve our students if we ignore distributional bargaining altogether. Unfortunately, many law students who are drawn to negotiation classes bring with them a fundamental discomfort with claiming value. Contrary to the stereotypes that attribute aggression and “sharp practices” to lawyers, many law students struggle to become more assertive. The Thomas–Kilmann Conflict Mode Instrument (TKI) is one tool that I have found can help raise students' awareness of, and comfort with, the reflexive responses to conflict that can impede their attempts to claim as well as create value in negotiation. The insights students gain from taking the TKI can be quickly put to use in the next negotiation role play. Although it may help students realize their dominant response to conflict, the TKI highlights that no single approach to negotiation is always best. Thus, the TKI can both encourage the reticent to claim more value in negotiation and suppress the seemingly insatiable appetites for value claiming that drive other students. When administering the TKI, I encourage students to learn at least four major lessons: 1 A negotiator has a choice in resolving the dilemma between value claiming and value creating. We are not just stuck with our reflexes. 2 Still, it is good to know what our reflexive response to conflict is likely to be so that we are more mindful of the choices as we make them. 3 Departing from reflexes requires energy: preparation, planning, mindfulness, and conscious effort. 4 Adaptability is desirable. A well-integrated negotiator might move from one TKI “type” to another as a negotiation progresses. In this article, I seek to give a very brief overview of the ways I have used the TKI to convey these lessons, increasing students' comfort with, and management of, value claiming. To this end, the article will describe the TKI, explain how I administer and debrief the students' encounter with it, and point out some potential pitfalls of this process.
Power class time-frequency representations: interference geometry, smoothing, and implementation

The nth power class (PC/sub n/) of quadratic time-frequency representations (QTFRs) is specifically suited for the multiresolution analysis of signals passing through systems whose dispersion characteristic is approximately f/sup /spl kappa//. This paper considers several aspects of PC analysis important in applications. We discuss the geometry of PC auto terms and cross terms, and we propose new PC QTFRs that attenuate cross terms via smoothing. We describe the implementation of PC QTFRs via warping techniques. Finally, simulation results demonstrate the advantages of PC analysis.
Role of antibiotic class in the rate of liberation of endotoxin during therapy for experimental gram-negative bacterial sepsis

To evaluate the role of antibiotic class in the rate of liberation of endotoxin during therapy for sepsis caused by gram-negative bacteria, we obtained serial blood samples from rabbits with sepsis caused by Escherichia coli and treated with chloramphenicol, gentamicin, or moxalactam. The concentrations of viable bacteria, free endotoxin, and total endotoxin in each blood sample were measured. In rabbits treated with chloramphenicol, the geometric mean levels of free endotoxin remained proportional to the geometric mean levels of bacteremia, a result indicating the absence of antibiotic-induced endotoxin liberation. In contrast, levels of free endotoxin increased rapidly while levels of bacteremia declined after treatment with gentamicin or moxalactam, a result indicating antibiotic-induced release of endotoxin. Despite similar rates of bacterial killing, mean levels of free endotoxin were as much as 20-fold higher in rabbits treated with moxalactam than in paired rabbits receiving gentamicin (P less than .05). These results indicate that endotoxin liberation during therapy for sepsis caused by gram-negative bacteria is dependent upon the class of antibiotic administered and is not necessarily correlated with the rate of bacterial killing.
Histone dynamics and roles of histone acetyltransferases during cold-induced gene regulation in Arabidopsis

In Arabidopsis, CBF transcription factors bind to and activate certain cold-regulated (COR) gene promoters during cold acclimation. Consistent with the prevailing model that histone acetylation and nucleosomal depletion correspond with transcriptionally active genes, we now report that H3 acetylation increases and nucleosome occupancy decreases at COR gene promoters upon cold acclimation. Overexpression of CBF1 resulted in a constitutive increase in H3 acetylation and decrease in nucleosome occupancy, consistent with the constitutive activation of COR gene expression. Overexpression of a truncated form of CBF2 lacking its transcriptional activation domain resulted in a cold-stimulated increase in H3 acetylation, but no change in nucleosomal occupancy or COR gene expression, indicating that histone acetylation is congruent with but not sufficient for cold-activation of COR gene expression. Plants homozygous for T-DNA disruption alleles of GCN5 (encoding a histone acetyltransferase) or ADA2b (a GCN5-interacting protein) show diminished expression of COR genes during cold acclimation. Contrary to expectations, H3 acetylation at COR gene promoters was stimulated upon cold acclimation in ada2b and gcn5 plants as in wild type plants, but the decrease in nucleosome occupancy was diminished. Thus, GCN5 is not the HAT responsible for histone acetylation at COR gene promoters during cold acclimation. Several other HAT mutant plants were also tested; although some do affect COR gene expression, none affected histone acetylation. Therefore, H3 acetylation at the COR gene promoters is not solely dependent on any of the HATs tested.
Short communication: skeletal maturation of children with sex chromosome abnormalities.

Summary: Skeletal maturity, or “bone age,” is one of the several criteria used to determine developmental or physiologic age as opposed to chronologic age. The purpose of this study of skeletal maturation of children with sex chromosome abnormalities (45,X, 47,XXX, 47,XXY, X-chromosomal mosaics) and controls is 2c-fold: (1) to investigate if children with sex chromosome aneuploidy ascertained in an unbiased fashion differ in skeletal maturation from their siblings and other normal healthy children born in Denver, Colorado, and (2) to assess if the skeletal age standards currently in use (Greulich-Pyle; Tanner-Whitehouse) are applicable to Denver children when evaluating radiographs for skeletal maturation. Mean chronologic and skeletal age were measured. Mean differences between skeletal and chronologic age for all groups across all measures were calculated. The 45,X females constitute the only group studied with bone ages lower than expected (0.05 > P > 0.01; two-tailed test). We found no other significant differences in skeletal maturation between Denver children with sex chromosome abnormalities and their siblings or the control sample of Denver children. Although we found the Tanner-Whitehouse standards to be more applicable for use with this population, all the Denver groups investigated yielded consistently lower bone ages than expected published norms. This is the first documentation in a group of children with sex chromosome abnormalities, ascertained in an unbiased fashion, that, with the exception of those with a 45,X karyotype, bone age is not significantly different from that of the normal population.
The dry pipeline of antiarrhythmic therapies.

Zimetbaum and Josephson (1) are conﬁdent that“new approaches to drug development and screening for risk foradverse events may ultimately reduce the toxicity of [antiarrhythmic]agents.” Unfortunately, this optimism has fallen on deaf ears in thepharmaceutical industry: The only “new” drugs to treat atrial ﬁbril-lation are dofetilide, ibutilide, and azimilide (2, 3). These class IIIantiarrhythmic agents, far from being bold breakthroughs in themanagement of atrial ﬁbrillation, are “niche” players (2) whose long-term efﬁcacy and toxicity are matters of speculation (3).The remaining antiarrhythmic agents that Zimetbaum and Jo-sephson advocate for patients in whom rate control fails, patientswho have contraindications to systemic anticoagulation, or patientswho were excluded from the Atrial Fibrillation Follow-up Investiga-tion of Rhythm Management (AFFIRM) study because of age orcomorbid conditions (4) have very high toxicities, including lethalarrhythmias. Furthermore, dosing is a matter of heated debate, andmonitoring is difﬁcult and expensive. Researchers should organizelarge trials using the hybrid therapies Zimetbaum and Josephsonadvocate to determine whether the combination of expensive andmarginally therapeutic drugs and ablative procedures is better thanrate control (4, 5).
VALVE DEVELOPMENT IN AULACODISCUS

A number of extant Aulacodiscus species collected in marine coastal habitats in California, Florida, Australia and Africa were examined with light and scanning electron microscopy. Information on the sequence of development in valves of this genus was inferred by the structures seen in immature specimens. Tubes grow outwardly from evenly spaced openings at the margins of the valve in the same position where internal flaps of silica initiate curved slits. Aulacodiscus scaber and A. petersii are similar in pattern of development and both have complex internal structures within their tubes. A. africanus and A. kittonii are another natural group with slitted external tube openings. A. argus is similar to the fossil species A. rogersii and A. grevilleanus; all have clusters of very small loculi in depressions with surrounding broad ridges and bullulae and can be presumed to have formed in like manner. The formation of the bubble-like bullulae was followed in A. oregonus and A. argus. Some features, visible in ...
Cholinergic Anionic Receptors II: Examination of a Conformationally Restricted Analog of Acetylcholine

The hydrolysis of acetylcholine consists of a number of stages, including the formation of an enzyme–substrate complex and the subsequent dissociation of this complex yielding the free enzyme, substrate, and new products. In these experiments compounds of structure similar to that of acetylcholine were tested in a cholinesterase system so as to determine their Km, or Ki values. This kinetic study led to useful information concerning the active site of the enzyme and the conformation of acetylcholine at the instant it binds with the enzyme.
High temperature superconducting ball formation in low frequency ac fields

The electric-field induced ball formation has been observed for high temperature superconducting (HTSC) powders in an ac field of low frequency. Different from a static electric field, the HTSC particles in the ac field first form chains along the field direction if the electric field is below a critical value, ${E}_{c1}.$ As soon as the electric field exceeds ${E}_{c1},$ the chains are broken and the HTSC particles form balls. The ball size reduces with further increase of the electric field. ${E}_{c1},$ as a function of frequency, first drops from the value for the static electric field and then increases with the frequency. The ball-formation phenomenon comes from the interaction between Cooper pairs and the applied electric field. A positive surface energy associated with the induced surface charge distributions on superconductors is a possible explanation.
Effects of nanocrystal size and device aging on performance of hybrid poly(3-hexylthiophene):CdSe nanocrystal solar cells

Abstract We have studied hybrid solar cells based on the polymer poly(3-hexylthiophene) (P3HT) and colloidal CdSe nanocrystals. Using CdSe nanospheres with varying size, we have found that the power conversion efficiency (ηP) of these devices increases monotonically with the CdSe nanocrystal size, from ηP=(0.39±0.04)% under AM1.5G solar illumination for 4.0±0.2 nm size nanospheres to ηP=(1.9±0.2)% for 6.8±0.5 nm size nanospheres. The efficiency increase with nanocrystal size is mostly due to a significant increase in the short-circuit current, whereas the open-circuit voltage and fill factor of the solar cells are less affected. The devices also exhibit abnormal initial aging behavior when exposed to air, as an increase in both the short-circuit current and open-circuit voltage during the first 30 min leads to a significant increase in ηP.
Wire-array z pinches as intense x-ray sources for inertial confinement fusion

Progress in pulsed power technologies has enabled the use of z pinches for inertial confinement fusion (ICF). Z pinches can provide x-ray powers of 200 TW and x-ray energies approaching 2 MJ. Computational capabilities have advanced to the point that 2-D radiation magneto-hydrodynamics computer codes can be used as detailed design tools. Several ICF configurations have been proposed. The z-pinch driven hohlraum configuration (ZPDH) uses two separate z pinches to provide the radiation to drive an ICF capsule. The decoupling of the z-pinch from the target in the ZPHD permits physics issues such as radiation production, transport, symmetry, and capsule hydrodynamics to be treated separately. The penalty is the increased energy requirement. ZPDH experiments have demonstrated the potential for acceptable capsule symmetry and radiation transport. The dynamic hohlraum concept uses the z pinch itself as a radiation case around the capsule providing the potential for very high coupling efficiency but at the expense of complex z-pinch/target coupling physics.
Mass transfer coefficient and concentration boundary layer thickness for a dissolving NAPL pool in porous media

Analytical expressions for the time invariant, average mass transfer coefficient and the concentration boundary layer thickness applicable to dissolving single-component nonaqueous phase liquid (NAPL) pools in two-dimensional, saturated, homogeneous and isotropic porous formations are derived. Good agreement between predicted and experimentally determined time invariant average mass transfer coefficients is observed.
Effect of cocaine use on outcomes in traumatic brain injury

Context: Animal and molecular studies have shown that cocaine exerts a neuroprotective effect against cerebral ischemia. Aims: To determine if the presence of cocaine metabolites on admission following traumatic brain injury (TBI) is associated with better outcomes. Settings and Design: Level-1 trauma center, retrospective cohort. Materials and Methods: After obtaining Institutional Review Board (IRB) approval, the trauma registry was searched from 2006 to 2009 for all patients aged 15-55 years with blunt head trauma and non-head AIS Statistical Analysis: Logistic regression was used to determine the independent effect of cocaine on mortality. Hospital LOS was compared with multiple linear regression. Results: A total of 741 patients met criteria and had drug screens. The screened versus unscreened groups were similar. Cocaine positive patients were predominantly African-American (46% vs. 21%, P P P = 0.01). There were no differences in mortality (cocaine-positive 1.4% vs. cocaine-negative 2.7%, P = 0.6) on both univariate and multivariate analysis. Conclusions: Positive cocaine screening was not associated with mortality in TBI. An effect may not have been detected because of the low mortality rate. LOS is affected by many factors unrelated to the injury and may not be a good surrogate for recovery. Similarly, GOS may be too coarse a measure to identify a benefit.
Covalency from quadrupole coupling in ABCI3 systems

The use of nuclear quadrupole data to determine covalency parameters is examined here. The empirical method considers both covalent and lattice contributions to the electric field gradient. In this first report for CsCOCI3, we find n− ⋍ fσ − fπ = 0.055 and a Sternheimer factor S = 27. The results in a series of ABCl3 compounds are compared to other methods for estimating covalency parameters.
NMR structure proofs for a series of substituted benzobicyclooctanes

Electrophilic additions to 5,8-dimethoxy-1,4-dihydro-1,4-ethanonaphthalene have produced a series of new products resulting from Wagner–Meerwein rearrangements. Proton and 13C NMR have been used to provide structure proofs for these molecules, which fall into two series of substituted benzobicyclooctanes. The full range of NMR techniques, i.e. lanthanide-induced shifts (LIS), difference NOEs and 2D NMR, have been employed. Proton and carbon chemical shifts are reported, and also a brief description is given of the more complex experimental results.
Suppression of luteinizing hormone secretion during short-term fasting in male rhesus monkeys: the role of metabolic versus stress signals.

One day of fasting leads to a significant suppression of pulsatile LH secretion in adult male rhesus monkeys that is evident within the first 4-6 h after a missed meal. Restricting food intake may suppress the central drive to the reproductive axis via metabolic signals occurring during the transition from a fed, energy storing state to a fasted, energy mobilizing state or via signals associated with the "psychological stress" imposed by withholding food. To distinguish between these two general types of signals, we chose the experimental strategy of providing monkeys with a great excess of calories on the day before fasting (i.e. overfeeding on the day before fasting) in order to maintain them in a metabolically fed state on the following day when they were fasted, without preventing the psychological stress associated with fasting. We reasoned that if metabolic signals are responsible for causing the fasting-induced suppression of LH secretion, overfeeding on the day before fasting would prevent the fas...
Characterization of the domain chaos convection state by the largest Lyapunov exponent.

Using numerical integrations of the Boussinesq equations in rotating cylindrical domains with realistic boundary conditions, we have computed the value of the largest Lyapunov exponent lambda1 for a variety of aspect ratios and driving strengths. We study in particular the domain chaos state, which bifurcates supercritically from the conducting fluid state and involves extended propagating fronts as well as point defects. We compare our results with those from Egolf et al., [Nature 404, 733 (2000)], who suggested that the value of lambda1 for the spiral defect chaos state of a convecting fluid was determined primarily by bursts of instability arising from short-lived, spatially localized dislocation nucleation events. We also show that the quantity lambda1 is not intensive for aspect ratios Gamma over the range 20<Gamma<40 and that the scaling exponent of lambda1 near onset is consistent with the value predicted by the amplitude equation formalism.
Epithelial regeneration and preservation of tracheal cartilage after tracheal replacement with cryopreserved allograft in the rat

Abstract Objective: We investigated the origin of the epithelium in transplanted cryopreserved tracheal allografts in rats and tried to clarify the mechanism by which immunogenicity is reduced in this procedure. Methods: Tracheal transplantation was performed with PVG rats (allele at the RT1 locus: c) used as donors and ACI rats (allele at the RT1 locus: a) as recipients. After resection of a 5-ring segment of the cervical trachea of an ACI rat, the trachea was reconstructed with the cryopreserved tracheal segment of a PVG rat ( n = 6). No immunosuppressive agents or steroids were given. Histologic changes were determined and immunohistochemical staining was performed to investigate major histocompatibility complex class I antigens of the transplanted tracheal segment. Results: Two months after tracheal transplantation, 6 surviving ACI rats were killed. Histologically, the epithelium and tracheal cartilage of the transplanted cryopreserved segment displayed normal structure. Immunohistochemical staining showed that the major histocompatibility complex class I antigen of the ACI rat was expressed in the epithelium of the transplanted segment and that the class I antigen of the PVG rat was expressed in the cartilage of the transplanted segment. Conclusions: After transplantation of the cryopreserved trachea, the epithelium of the transplanted cryopreserved segment originated from the recipient epithelium whereas the cartilage retained the structure of the donor trachea. We hypothesize that transplantation of a cryopreserved trachea leads to the growth of the recipient's epithelium over the donor trachea, thereby reducing the antigenicity of the transplant. (J Thorac Cardiovasc Surg 1998;116:624-7)
Distributed Processing of High-Speed Stereo Particle Image Velocimetry Data With a Low Power Beowulf Cluster

In this paper, we present our design of a portable cluster supercomputer created specifically for processing PIV image data. To make the system portable for a laboratory environment, the cluster computer is required to run on minimal power and be light weight. The final cluster design was based on the Intel® Quad-Core Xeon®X3210 low-power processors. This hardware setup allows for a total system consisting of twelve processing nodes with a total of 48 CPU cores, one master node with 5 TB of storage, and a Gigabit Ethernet connection. The total configuration along with the case has an approximate gross weight of 390 lbs and works well on one standard 120-V, 20-Amp electric circuit. With this cluster computer, a speedup of about 28 relative to standard serial processing of a PIV data set could be achieved.Copyright © 2007 by Utah State University
Noninvasive Brain Stimulation for Parkinson's Disease and Dystonia

Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are promising noninvasive cortical stimulation methods for adjunctive treatment of movement disorders. They avoid surgical risks and provide theoretical advantages of specific neural circuit neuromodulation. Neuromodulatory effects depend on extrinsic stimulation factors (cortical target, frequency, intensity, duration, number of sessions), intrinsic patient factors (disease process, individual variability and symptoms, state of medication treatment), and outcome measures. Most studies to date have shown beneficial effects of rTMS or tDCS on clinical symptoms in Parkinson’s disease (PD) and support the notion of spatial specificity to the effects on motor and nonmotor symptoms. Stimulation parameters have varied widely, however, and some studies are poorly controlled. Studies of rTMS or tDCS in dystonia have provided abundant data on physiology, but few on clinical effects. Multiple mechanisms likely contribute to the clinical effects of rTMS and tDCS in movement disorders, including normalization of cortical excitability, rebalancing of distributed neural network activity, and induction of dopamine release. It remains unclear how to individually adjust rTMS or tDCS factors for the most beneficial effects on symptoms of PD or dystonia. Nonetheless, the noninvasive nature, minimal side effects, positive effects in preliminary clinical studies, and increasing evidence for rational mechanisms make rTMS and tDCS attractive for ongoing investigation.
Controlling chromium vaporization from interconnects with nickel coatings in solid oxide devices

Abstract Vaporization of Cr-rich volatile species from interconnect materials is a major source of degradation that limits the lifetime of planar solid oxide devices (solid oxide fuel cells and solid oxide electrolysis cells) with metallic interconnects. Some metallic coatings (Ni, Co, and Cu) may significantly reduce the Cr release from interconnects and slow down the oxide scale growth on the steel substrate. To shed additional light upon the mechanisms of such protection and find a suitable coating material for ferritic stainless steel materials widely used for interconnects, we used a combination of first-principles calculations, thermodynamics, and diffusion modeling to investigate which factors determine the quality of the Ni metallic coatings. We found that Cr migration in Ni coatings is determined by a delicate combination of the nickel oxidation, Cr diffusion, and phase transformation processes. Although the formation of Cr2O3 is more exothermic than that of NiO, the kinetic rate of the chromia formation in the coating layer and its surface is significantly reduced by the low mobility of Cr in nickel oxide and in NiCr2O4 spinel. These results are in a good agreement with diffusion modeling for Cr diffusion through the Ni coating layer on the ferritic 441 steel substrate and available experimental data.
Alpha-particle energy straggling in solids☆

Abstract Energy straggling of 6.112 MeV alpha-particles in Al, Ag, and Au was measured. The results of the measurements for energy losses up to 750 keV are in much better agreement with theory than previously reported. No anomalous energy straggling was observed in the solids investigated. It is concluded that the width of the alpha-particle energy-loss distribution in solids is correctly predicted by existing energy-loss theory.
Building a Blog Cabin during a Financial Crisis Circuits of Struggle in the Digital Enclosure

In their studies of online media, political economists of communication have examined how firms like Google enclose users in a web of commercial surveillance, thus facilitating the commodification of their online labor. However, this focus on enclosure tends to overlook the political possibilities highlighted by autonomist Marxist theory—namely, that users, under certain circumstances, can appropriate these applications to contest conditions of exploitation. This article offers an analysis of Blog Cabin 2008, a cable home improvement show, in order to explore this tension between autonomy and enclosure. Our findings suggest that producers indeed used the show’s blog to exploit fans’ free labor. However, fans also used the blog to form social bonds, to press demands on the show’s producers, and to make connections between the show’s class politics and the wider financial crisis. A concluding section explores the theoretical and political significance of such unanticipated uses of the show’s blog.