cssi/SciSciGPT-SciSciNet huggingface dataset:
Connectivity and Nitrate Uptake Potential of Intermittent Streams in the Northeast USA

Non-perennial streams dominate the extent of stream networks worldwide. Intermittent streams can provide ecosystem services to the entire network – including nitrate uptake to alleviate eutrophication of coastal waters – and are threatened by lack of legal protection. We examined 12 intermittent streams in the temperate, humid climate of the Northeast USA. Over three years of monitoring, continuous flow was observed a median of 277 d yr-1, with no-flow conditions from early summer into fall. Estimated median discharge was 2.9 L s-1 or 0.36 mm d-1. All intermittent streams originated from source wetlands (median area: 0.27 ha) and the median length of the intermittent stream from the source wetland to the downstream perennial stream was 344 m. Through regional geospatial analysis with high resolution orthophotography, we estimated that widely available, “high resolution” (1:24,000) hydrography databases (e.g., NHDPlus HR) only displayed 43% of the total number of intermittent streams. Whole-stream gross nitrate-N uptake rates were estimated at six intermittent streams during continuous flow conditions using pulse additions of nitrate and a conservative tracer. These rates displayed high temporal variability (range: no detect to over 6000 mg N m-1 d-1); hot moments were noted in nine of the 65 pulse additions. Whole-stream gross nitrate-N uptake rates were significantly inversely related to discharge, with no measurable rates above 7 L s-1. Temperature was significantly positively correlated with whole-stream gross nitrate-N uptake rates, with more hot moments in the spring. Microbial assays demonstrated that nitrate cycling in intermittent streams are consistent with results from low order, perennial forested streams and highlighted the importance of debris dams and pools – potential locations for transient storage. Our assessment suggests that intermittent streams in our region may annually contribute 24-47% of the flow to perennial streams and potentially remove 4.1 to 80.4 kg nitrate-N km-2 annually. If development in these areas continues, perennial streams are in danger of losing a portion of their headwaters and potential nitrate uptake areas may become nitrate sources to downstream areas. These results argue to manage fluvial systems with a holistic approach that couples intermittent and perennial components.
Inertia Busters: Social Movement Influence on Impervious Incumbents facing Environmental Turbulence

Environmental change pressures incumbent organizations to decide when to adapt and exit from investments in a declining technology. As the alternatives become more economically feasible, companies ...
Identity for Kullback-Leibler divergence in density functional reactivity theory

Density functional reactivity theory (DFRT) makes use of simple electron density functionals to appreciate chemical reactivity. The Kullback-Leibler divergence, also called information gain or relative Shannon entropy, as a key component of the DFRT framework has entertained a few fascinating applications in the recent literature. For instance, it was employed to rationalize the Hirshfeld stockholder partition of atoms in molecules. It has also been applied to both determine regioselectivity and simultaneously quantify molecular electrophilicity and nucleophilicity, the capability of atoms in molecules to accept and donate electrons. In this work, we examine the local behavior of the Kullback-Leibler divergence and present a novel identity for it. The validity of the identity is subsequently verified by the numerical results of neutral atoms from He to Kr with different choices of the reference density. Analytical properties and local behaviors of the three new functions introduced in the identity are discussed. These new local functions, together with the identity unveiled in this work, should provide new perspectives for us to further develop the DFRT framework with added insights about the local behavior of molecular physiochemical properties.
Machine Learning Cyberattack and Defense Strategies

Abstract Cybersecurity is an increasingly important challenge for computer systems. In this work, cyberattacks were modeled using an extension of the well-known Petri net formalism. That formalism, designated Petri nets with players, strategies, and costs, models the states of the cyberattack and events during the attack as markings and transition firings in the net respectively. The formalism models the attacker and defender as competing players who may observe the marking of a subset of the net and based on the observed marking act by changing the stochastic firing rates of a subset of the transitions in order to achieve their competing goals. Rate changes by the players incur a cost. Using the formalism, nets were constructed to model specific cyberattack patterns (cross-site scripting and spear phishing) documented in the Common Attack Pattern Enumeration and Classification database. The models were validated by a panel of cybersecurity experts in a structured face validation process. Given those validated nets, a reinforcement learning algorithm using an -Greedy policy was implemented and set to the task of learning which actions to take, i.e., which transition rates to change for the different observable markings, so as to accomplish the goals of the attacker or defender. Experiments were conducted with a dynamic (learning) attacker against a static (fixed) defender, a static attacker against a dynamic defender, and a dynamic attacker against a dynamic defender. In all cases, the reinforcement learning algorithm was able to improve its performance, in terms of achieving the player’s objective and reducing the cost of doing so, over time. These results demonstrate the potential of formally modeling cyberattacks and of applying reinforcement learning to improving cybersecurity.
Two-Stage Stochastic Power Grid Expansion Considering Multiple N-1-1 Contingencies

A reliable power system expansion planning may be achieved by placing new transmission lines and generation units while checking the grid's survivability under different contingency scenarios with defined probabilities. This paper considers a stochastic optimization approach for the reliable expansion planning of a power system with a compliance check on economic dispatch and power flows under $N-1-1$ contingencies with corrective actions. This yields a complex large-scale mixed-integer linear programming (MILP) optimization problem. For an efficient solution, a Benders Decomposition algorithm is adapted. The algorithm and model are assessed on modified versions of IEEE test systems, and computational experiments are performed to validate the effectiveness of the proposed method.
An Alternatively Translated Connexin 43 Isoform, GJA1-11k, Localizes to the Nucleus and Can Inhibit Cell Cycle Progression

Connexin 43 (Cx43) is a gap junction protein that assembles at the cell border to form intercellular gap junction (GJ) channels which allow for cell-cell communication by facilitating the rapid transmission of ions and other small molecules between adjacent cells. Non-canonical roles of Cx43, and specifically its C-terminal domain, have been identified in the regulation of Cx43 trafficking, mitochondrial preconditioning, cell proliferation, and tumor formation, yet the mechanisms are still being explored. It was recently identified that up to six truncated isoforms of Cx43 are endogenously produced via alternative translation from internal start codons in addition to full length Cx43, all from the same mRNA produced by the gene GJA1. GJA1-11k, the 11kDa alternatively translated isoform of Cx43, does not have a known role in the formation of gap junction channels, and little is known about its function. Here, we report that over expressed GJA1-11k, unlike the other five truncated isoforms, preferentially localizes to the nucleus in HEK293FT cells and suppresses cell growth by limiting cell cycle progression from the G0/G1 phase to the S phase. Furthermore, these functions are independent of the channel-forming full-length Cx43 isoform. Understanding the apparently unique role of GJA1-11k and its generation in cell cycle regulation may uncover a new target for affecting cell growth in multiple disease models.
Using Small Business Banking Data for Explainable Credit Risk Scoring

Machine learning applied to financial transaction records can predict how likely a small business is to repay a loan. For this purpose we compared a traditional scorecard credit risk model against various machine learning models and found that XGBoost with monotonic constraints outperformed scorecard model by 7% in K-S statistic. To deploy such a machine learning model in production for loan application risk scoring it must comply with lending industry regulations that require lenders to provide understandable and specific reasons for credit decisions. Thus we also developed a loan decision explanation technique based on the ideas of WoE and SHAP. Our research was carried out using a historical dataset of tens of thousands of loans and millions of associated financial transactions. The credit risk scoring model based on XGBoost with monotonic constraints and SHAP explanations described in this paper have been deployed by QuickBooks Capital to assess incoming loan applications since July 2019.
Edward Thring’s Theory, Practice and Legacy: Physical Education in Britain since 1800

Health of body, health of intellect, health of heart, all uniting to form the true man, and being the common object of teacher and taught. Edward Thring, Education and School (London: Macmillan, 18...
Transmission of SARS-CoV-2 from asymptomatic and presymptomatic individuals in healthcare settings despite medical masks and eye protection.

We describe 3 instances of SARS-CoV-2 transmission despite medical masks and eye protection, including transmission despite the source person being masked, transmission despite the exposed person being masked, and transmission despite both parties being masked. Whole genome sequencing confirmed perfect homology between source and exposed persons' viruses in all cases.
Estimation of cerebral O2 consumption with 2-photon phosphorescence microscopy

The cerebral cortex is organized in cortical layers that differ in their cellular density, composition, and wiring. Cortical laminar architecture is also readily revealed by staining for cytochrome oxidase – the last enzyme in the respiratory electron transport chain located in the inner mitochondrial membrane. I has been hypothesized that a high-density band of cytochrome oxidase in cortical layer IV reflects higher oxygen consumption under baseline (unstimulated) conditions. Here, we test the hypothesis using direct measurements of the partial pressure of O2 (pO2) in cortical tissue obtained with 2-photon phosphorescence lifetime microscopy (2PLM). We revisit our previously developed method for extraction of cerebral metabolic rate of O2 (CMRO2) based on 2-photon pO2 measurements around diving arterioles and apply this method to estimate baseline CMRO2 in awake mice across cortical layers. Our results show that, in contrary to the common notion, baseline CMRO2 in layer IV is not higher than that in upper layers. We speculate that the cytochrome oxidase band in layer IV may reflect higher metabolic demands during transient surges in neuronal activity. These findings are important for interpretation of cortical-layer-resolved Blood Oxygen Level Dependent (BOLD) functional Magnetic Resonance Imaging (fMRI) studies.
Diagnostic performance of Milan system for reporting salivary gland cytopathology: A prospective study

Background Fine-needle aspiration (FNA) is a well-established modality for diagnosing salivary gland pathologies. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) provides a standardized uniform framework leading to an evidence-based risk of malignancy (ROM). Based on the current literature, ROM in the 6-tier MSRSGC ranges from 90% for the malignant category. Here, we report our institutional experience adopting MSRSGC. Methods The cytopathology group at our institution implemented MSRSGC at the end of 2018. Through a query of our laboratory information system, we identified all salivary gland FNA cases from 27 November 2018 to 26 October 2020. The pertinent surgical pathology follow-up was also extracted. After manual curation, data was analyzed in Rv4.0.2. Results Our cohort comprised of 315 patients undergoing 343 salivary gland FNA biopsies, predominantly on the parotid (90%), 162 with a surgical pathology follow-up. The risk of malignancy ranged from 3.2% in neoplasm-benign (IVA) to 100% in suspicious for malignancy (V) and malignant (VI) categories. ROM in the other categories was: 12.5% for non-diagnostic, 0 for non-neoplastic, 33.3% for atypia of undetermined significance, and 41.9% for salivary gland neoplasm of uncertain malignant potential (SUMP). Most SUMP cases had a basaloid or oncocytoid cytomorphology with similar ROM. In distinguishing benign and malignant salivary gland lesions, FNA had adequacy of 93.6%, a diagnostic yield of 62.2%, a sensitivity of 93.1% and a specificity of 100%. Conclusions MSRSGC was successfully adopted by our cytology group and clinicians, with overall diagnostic performance similar to previous studies.
An accurate particle-mesh method for simulating charged particles in wall-bounded flows

Abstract A numerical framework for accurately computing electrically charged particles in wall-bounded flows is presented. This work builds upon the particle-particle particle-mesh (P3M) approach, which is traditionally restricted to cubic periodic domains. Here we propose an extended approach that retains the same accuracy and cost savings for non-periodic wall-bounded flows. The solution to the electric Poisson equation is performed agnostic to the presence of any walls, allowing for the use of fast Fourier transforms. The contribution from periodic images are removed by exploiting the linearity of the Poisson equation and strategically mapping the particle charge to the grid. A signed-distance levelset function is used to enforce appropriate boundary conditions. The accuracy of the proposed approach is quantified and compared to existing schemes. The framework is then demonstrated on a polydisperse distribution of charged particles in a turbulent pipe flow. The effect of charge on velocity statistics and deposition rate is reported.
Estimating Proton Stopping Power Ratio of a Novel Iodinated Rectal Hydrogel Spacer Using Dual Energy Computed Tomography.

PURPOSE/OBJECTIVE(S) A novel iodinated rectal hydrogel spacer (I-RS) has been developed to make the gel radiopaque on CT compared to the standard rectal hydrogel spacers (S-RS). As the iodine in I-RS strongly absorbs kV photons, the accuracy of currently employed CT calibration built into a single energy CT (SECT) becomes inaccurate to determine the proton stopping power ratio (PSR) of the injected gel. Direct measurements of PSR mediated by I-RS with proton beams has been reported; however, those measurements were conducted under ideal conditions without fully accounting for density heterogeneity mediated by air bubbles co-injected with the gel during placement. This study used dual-energy CT (DECT) to estimate I-RS PSR in patients undergoing CT simulation for prostate cancer (PCa) radiotherapy (RT). MATERIALS/METHODS Sequential scans at 90 and 140 kVp were acquired for 7 intact PCa (I-RS n = 5, S-RS n = 2) on a Philips Brilliance scanner. PSR was reconstructed following the method proposed by Torikoshi and improved by Yang, and compared to similar measurements when I-RS was replaced with S-RS. A pre-calculated table correlating effective atomic number with all possible Hounsfield Unit (HU) combinations from two sequential scans was implemented to accelerate reconstruction. PSRs were compared between DECT and SECT, and between I-RS and S-RS. RESULTS In gel, HU measurements were heterogeneous (range -372 - +358). The mean PSR on reconstruction when using DECT was 0.966 (0.940-0.980) for I-RS. Replacement of I-RS with S-RS HU density resulted in a mean PSR of 0.937 (0.926-0.941) by DECT. PSR for I-RS on SECT was 1.107, and 1.014 for S-RS. The estimated difference between PSR in I-RS and S-RS on DECT vs. SECT were 14% and 8%, respectively. CONCLUSION These data demonstrate that the use of I-RS in proton RT treatment planning could overestimate proton range due to underestimating PSR when CT simulation is performed using standard SECT. Notably, PSR absolute value reported here is different compared to previously reported in vitro data under ideal conditions and may be related to differences in gel heterogeneity in vivo. Heterogeneity is highlighted by the wide range of gel HU measurements. Direct measurements of PSR will be obtained in a planned future experiment. These data suggest that PSR overestimation due to I-RS should be considered when planning PCa treatment using proton therapy for patients who get I-RS to reduce treatment toxicity.
Measuring turnover rates in the nonstead state.

It is very difficult to define the steady and nonsteady biological states precisely. If a labeled compound is introduced into a non-growing, healthy (and presumably “steady-state”) animal, the specific activity of the labeled compound is found to decrease with time. This decrease has been interpreted as being due to the turnover of the substance. There is also a decrease in specific activity when the same procedure is carried out in animals obviously not in a steady state (growth, wasting disease, etc.). However, this latter specific activity decrease may or may not be due to the turnover of the substance.
Invasive EEG in the definition of the seizure onset zone: subdural electrodes

Publisher Summary Subdural grid evaluation is safe and useful in defining the region of ictal onset in adults and children being evaluated for resective epilepsy surgery. Chronic recording from epileptogenic cortex and subsequent cortical stimulation to determine the extent of the focus and the function of surrounding cortex is a well-established technique for planing a surgical strategy. The chapter focuses on the advantages, the disadvantages, and the limitations of the method in comparison to extracranial recordings and the other methods of invasive recording. Further, it will cover the value of this method in the presurgical evaluation of specific localization-related epilepsies of different topographies, lesional cases due to different etiologies, e.g., focal cortical dysplasia and in nonlesional cases. Finally, the chapter discusses the prognostic value of subdural electrode (SDE) evaluation with regard to the surgical outcome and the issue of reevaluation with invasive SDE for epilepsy surgery.
Response strengths and choice probability : a consideration of two combination rules

Publisher Summary This chapter focuses on the area of preferential choice behavior that is a field of much interest and activity among experimental psychologists from a long time. The simple choice experiments are to be thought of as placing into competition two or more instrumental responses, each of which may vary independently in its strength. To handle these situations, the theorist must propose some solution to the question that when two competing responses with known strengths are given, then what is the composition or combination rule by which choice probability is related to the strengths of the separate responses Within this area of reference, two major theories are established. One theory is proposed by Thurstone and it assumes that the probability of choosing response A over B is an increasing function of the difference in strengths of the two responses. The second major theory that is proposed by Luce assumes that the choice of A over B is determined by the ratio of their strengths. Therefore, if A and B have equal strengths, then A is chosen half the time; if A is three times stronger than B, then A can be chosen three-quarters of the time, and so on.
Computer-assisted analysis of the therapy of acute salpingitis

Isolation rates of microorganisms recovered by culdocentesis and/or laparoscopy in nine studies of salpingitis were multiplied by the proportions of each species which would be inhibited in vitro at peak and 1/2 peak serum levels of 13 antimicrobial drugs to yield a prediction of efficacy for the drugs. Efficacies of several hundred combinations of two and three of these drugs were estimated also. Some pairs of oral drugs were predicted to be as efficacious as some parenteral regimens of two or three drugs now in use. The predictions with this model parallel the results of some recently reported studies of therapy for salpingitis, and the model may prove to be a useful tool for future trials and therapy.
Climate Change, Atmospheric Rivers, and Floods in California – A Multimodel Analysis of Storm Frequency and Magnitude Changes1

Dettinger, Michael, 2011. Climate Change, Atmospheric Rivers, and Floods in California – A Multimodel Analysis of Storm Frequency and Magnitude Changes. Journal of the American Water Resources Association (JAWRA) 47(3):514-523. DOI: 10.1111/j.1752-1688.2011.00546.x Abstract: Recent studies have documented the important role that “atmospheric rivers” (ARs) of concentrated near-surface water vapor above the Pacific Ocean play in the storms and floods in California, Oregon, and Washington. By delivering large masses of warm, moist air (sometimes directly from the Tropics), ARs establish conditions for the kinds of high snowlines and copious orographic rainfall that have caused the largest historical storms. In many California rivers, essentially all major historical floods have been associated with AR storms. As an example of the kinds of storm changes that may influence future flood frequencies, the occurrence of such storms in historical observations and in a 7-model ensemble of historical-climate and projected future climate simulations is evaluated. Under an A2 greenhouse-gas emissions scenario (with emissions accelerating throughout the 21st Century), average AR statistics do not change much in most climate models; however, extremes change notably. Years with many AR episodes increase, ARs with higher-than-historical water-vapor transport rates increase, and AR storm-temperatures increase. Furthermore, the peak season within which most ARs occur is commonly projected to lengthen, extending the flood-hazard season. All of these tendencies could increase opportunities for both more frequent and more severe floods in California under projected climate changes.
Effects of serial and concurrent training on acquisition and generalization

Despite a large body of research demonstrating that generalization to novel stimuli can be produced by training sufficient exemplars, the methods by which exemplars can be trained remain unclear. The purpose of the current study was to evaluate 2 methods, serial and concurrent presentation of stimuli, to train sufficient exemplars. Five preschool children with developmental delays were taught to identify letters or letter sounds using serial and concurrent presentation. Generalization to untrained exemplars was evaluated for targets trained using each method. Participants reached the mastery criterion in fewer training sessions, on average, using the concurrent method of presentation than the serial method, and the concurrent method also resulted in greater generalization to untrained exemplars.
Navigating without a road map.

HISTORY shows that unplanned, unanticipated discoveries in model organisms have had a major impact on the creation of new knowledge leading to a deeper understanding of human disease. By definition, unanticipated discoveries fall outside the boundaries of prospective road maps. I will use my own research path to illustrate the point, but not because my story is exceptional. It derives power from the fact that it is commonplace.
Improved performance of selectively oxidized visible VCSELs

The recent development of infra-red selectively oxidized vertical cavity surface emitting lasers (VCSELs) has been enabled through improvement of the oxide aperture design within the laser cavity. VCSEL designs using thin oxide apertures offset a few periods away from the optical cavity have been demonstrated to reduce optical confinement and loss. 650 nm and shorter wavelengths are important for optical scanning applications and low cost optical interconnects based on plastic optical fiber (POF). For example POF has minimum attenuation at 650 nm, indicating that visible VCSELs are appropriate for the development of gigabit/sec low cost optical data links. We report the improved performance of selectively oxidized visible VCSELs which employ a single thin offset oxide aperture.
Oil-Aging Mechanism on 52100 Steel with Hydrocarbon Oils Containing Tricresyl Phosphate (TCP)

Experience has shown that the lubrication behavior of steel bearings can be significantly improved by a pretreatment called oil aging. Neat tricresyl phosphate (TCP) is normally used for this process (1)—(4). In this study, however, two hydrocarbon-type oils, each containing one percent TCP, were used for oil aging 52100 steel specimens under a variety of experimental conditions. Each coating formed as a result of the oil-aging process was analyzed by electron spectroscopy for chemical analysis (ESCA). The results indicate that microscale oxidation of the base oil and preferential adsorption phenomena within the oil system components are necessary for the formation of a desirable coating, including a phosphate type of material. The absence of aromatics and polar contaminants in the lubricant is also a determinant factor for the formation of a phosphate coating. The nature of this phosphate and the mechanism of its formation are explained. Presented at the 39th Annual Meeting in Chicago, Illinois, May 7–10...
Intraperitoneal deferoxamine therapy for iron overload in children undergoing CAPD

Intraperitoneal deferoxamine therapy for iron overload in children undergoing CAPD. We treated three children with renal failure and chronic iron overload with intraperitoneal deferoxamine therapy. Each child had an elevated serum ferritin level, a dense liver as measured by computerized tomography (Hounsfield Units) and one had dialysis related porphyria cutanea tarda. Deferoxamine therapy (10 to 17.5 mg/kg) was given in the overnight exchange for three to six months. Prior to therapy, iron was not detected in the dialysate; during the course of therapy, daily dialysate iron removal averaged 5652 µg, 2241 µg and 4028 µg in the three children. The serum ferritin level fell during the course of therapy in two children who were estimated to be in negative iron balance, and was unchanged in the third who was estimated to be in positive iron balance due to frequent transfusions. In 10 children with chronic renal failure, there was a linear correlation (r=0.855; P
Heart failure incidence and survival (from the Atherosclerosis Risk in Communities study).

Heart failure (HF) is increasing in prevalence in the United States. Little data exists on race and gender differences in HF incidence rates and case fatality. The Atherosclerosis Risk in Communities (ARIC) cohort is a population-based study from 4 United States communities (1987 to 2002). Prevalent HF cases (n = 750) were identified by self-report and were excluded. Incident HF was defined by the International Classification of Diseases codes for HF (428.0 to 428.9, I50) from a hospitalization (n = 1,206) or death certificate (n = 76). There were 1,282 incident HF cases over 198,417 person-years. The age-adjusted incidence rate (per 1,000 person-years) for Caucasian women, 3.4, was significantly less compared with all other groups (Caucasian men, 6.0; African-American women, 8.1; African-American men, 9.1). Age-adjusted HF incidence rates were greater for African-Americans than Caucasians, but adjustment for confounders attenuated the difference. The adjusted African-American-to-Caucasian hazard ratio was 0.86 (95% confidence interval, 0.70 to 1.06) for men, and similarly, 0.93 (95% confidence interval, 0.46 to 1.90) for women during the second half of follow-up. The hazard ratio for women during the first half of follow-up was 1.79 (95% confidence interval, 1.25 to 2.55). Thirty-day, 1-year, and 5-year case fatalities following hospitalization for HF were 10.4%, 22%, and 42.3%, respectively. African-Americans had a greater 5-year case fatality compared with Caucasians (p
Replacement of All α-Domain Lysines with Glutamates Reduces Metallothionein Detoxification Function

Abstract Mammalian metallothioneins (MTs) possess eight highly conserved lysine residues, including three in each of two metal binding domains. We used site-directed mutagenesis to replace these intradomain lysines in Chinese hamster ovary MT2 with glutamic acid and/or glutamine. These mutant MTs were expressed in a metal sensitive yeast host. One mutant which had all three lysines in the α-domain replaced by glutamates (K43,51,56E) exhibited a reduced ability, relative to native MT, to protect yeast transformants against otherwise toxic levels of cadmium. This triply substituted mutant also exhibited anomalous migration on a non-denaturing gel relative to wild type MT and other MT lysine mutants, suggesting that the intradomain lysines are important in maintaining the conformational integrity of MT.
INHIBITION OF GABA-GATED CHLORIDE CHANNELS IN BRAIN BY THE ARACHIDONIC ACID METABOLITE, THROMBOXANE A2

Abstract Previously, we showed that arachidonic acid and prostaglandin metabolites inhibited GABA A responses in rat cerebral cortex. Thromboxane A 2 (TXA 2 ), a metabolite of arachidonic acid, has potent actions on blood vessels and platelets, but its actions on neurons are not known. Here, we examined the effects of several TXA 2 analogs on the functional and binding characteristics of GABA A receptors in rat brain. The stable analogs of TXA 2 , pinane and carbocyclic TXA 2 , and the TXA 2 agonist, U-46619, inhibited muscimol-induced 36 Cl − uptake in cerebral cortical synaptoneurosomes. Carbocyclic TXA 2 decreased the maximal response to muscimol, consistent with a non-competitive interaction. The TXA 2 antagonist, SQ 25,548, did not block the effects of either arachidonic acid or carbocyclic TXA 2 . Neither the biologically inactive metabolite of TXA 2 , TXB 2 , nor carbacyclin, a stable analog of prostacyclin (prostaglandin I 2 ) had an effect on GABA A responses. Thus the pharmacology differs from that in vascular smooth muscle and platelets. To determine if GABA A receptors were sensitive to the thromboxanes, the effect of pinane TXA 2 on the binding of [ 35 S] t -butylbicyclophosphorothionate ([ 35 S]TBPS) to GABA-gated Cl − channels was measured using receptor autoradiography. Pinane TXA 2 inhibited [ 35 S]TBPS binding in a regionally selective and non-competitive manner; the greatest inhibition was in the cerebral cortex, hippocampus and striatum, areas which are selectively vulnerable to cerebral ischemia. We conclude that TXA 2 can interact with neuronal membranes to inhibit GABA receptor function, independent of its actions on the cerebrovasculature and on glial cells. This may be important during pathologic states such as ischemia, when TXA 2 accumulates in extracellular spaces. Copyright © 1996 Elsevier Science Ltd.
Ab initio molecular dynamics around a conical intersection: Li(2p) + H2

We present ab initio multi-electronic state molecular dynamics for a polyatomic complex accessing a conical intersection. The potential energy surfaces and their couplings are generated simultaneously with the solution of the nuclear Schrodinger equation. For the chosen example, nonadiabatic transitions are extraordinarily fast (< 10 fs) and the quenching efficiency is greatly diminished by recrossing from the lower to the upper adiabatic electronic state. We observe electronic quenching followed by both inelastic and reactive scattering, a testament to the flexibility of the ab initio potential energy surfaces and our allowance for wavepacket bifurcation in multiple spawning dynamics.
Effects of Prostaglandins on the Aqueous Humor Outflow Pathways

Topical treatments with certain prostaglandins (PGs), including FP receptor agonists, lower intraocular pressure by increasing uveoscleral outflow. Although the precise mechanism for the increased uveoscleral outflow is not known, there appears to be activation of a molecular transduction cascade and an increase in the biosynthesis of certain metalloproteinases. This leads to reduction of extracellular matrix components within the ciliary muscle, iris root, and sclera. It is possible that this reduction of extracellular matrix present within portions of the uveoscleral pathway may contribute to the mechanism of increased uveoscleral outflow. Additional mechanisms that may contribute to the PG-mediated increase of uveoscleral outflow include relaxation of the ciliary muscle, cell shape changes, cytoskeletal alteration, or compaction of the extracellular matrix within the tissues of the uveoscleral outflow pathway. Future studies should clarify the importance of these various responses that may contribute to increased uveoscleral outflow. At present, there is no compelling evidence for a substantial facility-increasing effect on the trabecular meshwork outflow for any of these compounds.
Early detection of acute tubular injury with diffusion-weighted magnetic resonance imaging in a rat model of myohemoglobinuric acute renal failure.

We evaluated the feasibility of magnetic resonance imaging (MRI)for early detection of tubular injury by monitoring changes in the apparent diffusion coefficient (ADC) of renal water in a rat model of myohemoglobinuric glycerol-induced acute renal failure (ARF). Diffusion-weighted MRI was performed concurrently with measurements of serum creatinine and blood urea nitrogen (BUN), evaluation of renal perfusion with dynamic contrast-enhanced MRI, and renal morphological examination. ADC values in the cortex and outer medulla significantly declined within minutes after the glycerol administration (70–75% of control at 4 min and 50–60% of control at 15 min). Contrast-enhanced MRI demonstrated renal hypoperfusion at 20 min after the onset of injury. Light microscopy showed normal glomeruli and edematous tubular epithelial cells at 10 and 30 min, with more severe swelling and protein casts at 30 min. No changes in serum creatinine or BUN levels were detected. We hypothesize that decrease in renal ADC may be attr...
Thermal and mechanical modeling analysis of laser-assisted micro-milling of difficult-to-machine alloys

Abstract This study is focused on numerical modeling analysis of laser-assisted micro-milling (LAMM) of difficult-to-machine alloys, such as Ti6Al4V, Inconel 718, and stainless steel AISI 422. Multiple LAMM tests are performed on these materials in side cutting of bulk and fin workpiece configurations with 100–300 μm diameter micro endmills. A 3D transient finite volume prismatic thermal model is used to quantitatively analyse the material temperature increase in the machined chamfer due to laser-assist during the LAMM process. Novel 2D finite element (FE) models are developed in ABAQUS to simulate the continuous chip formation with varying chip thickness with the strain gradient constitutive material models developed for the size effect in micro-milling. The steady-state workpiece and tool cutting temperatures after multiple milling cycles are analysed with a heat transfer model based on the chip formation analysis and the prismatic thermal model predictions. An empirical tool wear model is implemented in the finite element analysis to predict tool wear in the LAMM side cutting process. The FE model results are discussed in chip formation, flow stresses, temperatures and velocity fields to great details, which relate to the surface integrity analysis and built-up edge (BUE) formation in micro-milling.
Theranostics: Combining Imaging and Therapy

Employing theranostic nanoparticles, which combine both therapeutic and diagnostic capabilities in one dose, has promise to propel the biomedical field toward personalized medicine. This review presents an overview of different theranostic strategies developed for the diagnosis and treatment of disease, with an emphasis on cancer. Herein, therapeutic strategies such as nucleic acid delivery, chemotherapy, hyperthermia (photothermal ablation), photodynamic, and radiation therapy are combined with one or more imaging functionalities for both in vitro and in vivo studies. Different imaging probes, such as MRI contrast agents (T1 and T2 agents), fluorescent markers (organic dyes and inorganic quantum dots), and nuclear imaging agents (PET/SPECT agents), can be decorated onto therapeutic agents or therapeutic delivery vehicles in order to facilitate their imaging and, in so doing, gain information about the trafficking pathway, kinetics of delivery, and therapeutic efficacy; several such strategies are outline...
Lithium, rubidium and cesium: cerebral pharmacokinetics and alcohol interactions.

Abstract The distribution of exogenously administered Li+, Rb+ and Cs+ in distinct mouse brain regions was studied as a function of time subsequent termination of a short-term daily treatment with these alkali metal salts. The resulting distribution profiles were compared with that obtained from the corresponding endogenous alkali metals. Endogenous Rb+ and Cs+ were readily measurable in all 6 brain regions studied compared to traces of measurable Li+. The Rb+ concentration was greater than that of Cs+. Short-term treatment with equal doses of the alkali metals studied showed greater brain accumulation of Rb+ and Cs+ than Li+ with a prolonged brain regions preference for Cs+ storages as a function of time. Duration of ethanol-mediated narcosis was reduced from saline controls by pretreatment with RbCl or CsCl as contrasted with prolongation by LiCl. The narcotic dosage of ethanol used reduced endogenous Li+ and increased Cs+ levels in the cerebellum. This massive ethanol dosage exerted little effect on the distribution of exogenously administered Cs+ with exception of the striatum which continued to show a high content of Cs+. This may have contributed to partial antagonism of ethanol-depressant action and to restoring of motor function, i.e., rapid regaining of righting reflex. The results showed that Cs+ possessed longer biological life time in the brain than Rb+ or Li+ which may be of therapeutic value, i.e., in the use of Cs salts in treatment of brain tumors and in conjuction with psychoactive agents provided the respective chemotherapeutic and antidepressant properties of CsCl have been established.
Penguins everywhere: GNU/Linux in Antarctica

The harsh, remote conditions of the Antarctic ice cap pose formidable challenges to continuous, year-round geophysical data acquisition. The author designed and built a serial data-acquisition engine using the GNU/Linux operating system on a small single-board computer to remotely record earthquakes.
Effect of Polydispersity on the Depletion Interaction between Colloidal Particles

The effect of polydispersity on the depletion interaction in hard-sphere systems is investigated theoretically. The depletion force and energy between two parallel plates and two spherical particles in a solution of nonadsorbing, hard spherical macromolecules is calculated via a general force-balance approach. The diameter of the macromolecules is assumed to be normally distributed and the polydispersity in diameter is characterized with the coefficient of variation (ratio of the standard deviation to the mean). The primary assumption is that the density of macromolecules is low enough that higher order effects arising from interactions between macromolecules are negligible. It is found that the interaction between parallel plates can be represented in terms of a complementary error function of a dimensionless separation distance. These results are then applied to spherical particles via the Derjaguin approximation. A set of general and relatively simple equations for force and energy are developed that are shown to be valid in both monodisperse and polydisperse systems. For spherical particles in a solution of macromolecules at fixed number density, polydispersity is predicted to increase the range and magnitude of the depletion force. The effect is relatively small, however, unless the polydispersity is substantial (e.g., coefficients of variation greater than 50%).
Winner-take-all dynamics in an optoelectronic feedback circuit for image processing

Systems for processing high resolution images need to be fast, compact, and efficient. Image processing systems that incorporate optics into its architecture can provide the speed and potentially the compactness to meet the demands of analyzing images. In this paper a hybrid approach to image analysis using Winner Take All neural network dynamics with optical and electronic implementation is discussed. Resulting images from the system simulations are explored for use in object and background discrimination for image segmentation tasks.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Resolution of molecular weight distributions in slightly pyrolyzed cellulose using the weibull function

Even before weight loss in the low-temperature pyrolysis of cellulose becomes significant, the average degree of polymerization of the partially pyrolyzed samples drops sharply. The gel permeation chromatograms of nitrated derivatives of the samples can be described in terms of a small number of mixed size populations—each component fitted within reasonable limits by a Weibull distribution function. The modal value of each component is taken as an integral multiple of a “macromonomer” of nominal degree of polymerization 228.4. Thus, the data are consistent with a model in which the degradation process is assumed to involve bond rupture at specific “weak links” into particularly favored molecular sizes. Such a mechanism provides a plausible alternative to the commonly assumed random breakdown along the length of the molecule.
Analytical Decomposition of Wing Roll and Flapping Using Lifting-Line Theory

A decomposed Fourier-series solution to Prandtl’s classical lifting-line theory is used to examine the effects of rigid-body roll and small-angle wing flapping on the lift, induced-drag, and power coefficients developed by a finite wing. This solution shows that, if the flapping rate for any wing is large enough, the mean induced drag averaged over a complete flapping cycle will be negative, that is, the wing flapping produces net induced thrust. For quasi-steady flapping in pure plunging, the solution predicts that wing flapping has no net effect on the mean lift. A significant advantage of this analytical solution over commonly used numerical methods is the utility provided for optimizing wing-flapping cycles. The analytical solution involves five time-dependent functions that could all be optimized to maximize thrust, propulsive efficiency, and/or other performance measures. Results show that, by optimizing only one of these five functions, propulsive efficiencies exceeding 90% can be attained. For the...
Why Don't Children Take Their Asthma Medications? A Qualitative Analysis of Children's Perspectives on Adherence

Focus groups were conducted with children with asthma to generate descriptive data regarding asthma adherence. Transcripts of focus groups were analyzed using qualitative methods. Data collection occurred at an outpatient department of a university‐affiliated hospital and at a summer camp for children with asthma. Thirty‐six children with asthma ranging in age from 9 years, 1 month to 15 years, 3 months (M age = 11 years, 10 months) participated. Participants provided qualitative descriptions of asthma experiences, including consequences, adherence barriers, and strategies to improve adherence. Researchers also elicited participants' feedback regarding theoretically derived strategies to improve adherence. Children's perceived consequences of asthma included feeling ill, limitations on peer interactions, and medication annoyances. Frequently endorsed barriers to medication adherence were lack of motivation, difficulties remembering, and social barriers. Child‐generated strategies to improve adherence incl...
Development of an integrated microfluidic platform for dynamic oxygen sensing and delivery in a flowing medium.

This paper describes a platform for real-time sensing of dissolved oxygen in a flowing microfluidic environment using an oxygen-sensitive luminescent dye (platinum octaethylporphyrin ketone) integrated into a micro-oxygenator device. Using a phase-based detection method, the luminescent decay lifetime of the dye was consistent with the linear Stern–Volmer relationship using both gaseous and aqueous samples. Maximum sensor resolution varied between 120–780 ppb across a range of dissolved oxygen (DO) concentrations ranging from 0–42.5 ppm. The sensor was subsequently used to determine the convective mass-transfer characteristics of a multi-layer polydimethylsiloxane (PDMS) microfluidic oxygenator. The membrane-based oxygenator showed excellent agreement with an analytical convection model, and the integrated oxygen sensor was accurate across a wide range of tested flow rates (0.05–5 mL min−1). The device is unique for its ease of fabrication and highly flexible configuration, as well as the novel incorporation of oxygen delivery and detection in a single micro-device. Potential applications include tissue engineering, cell culturing, and miniaturized bio-assays that require the delivery and/or detection of precise quantities of oxygen within a microfluidic construct.
The use of sacral neuromodulation for the treatment of non-obstructive urinary retention secondary to Guillain-Barré syndrome

Guillain-Barre syndrome, an acute autoimmune polyneuropathy and demyelinating disease, is characterized by weakness, sensory loss, areflexia, pain, autonomic dysfunction, and occasionally, micturition disturbances including voiding difficulty, urinary retention, nocturnal urinary frequency, and urge incontinence. Typically, urinary dysfunction resolves simultaneously with other neurologic deficits. We report the case of a 20-year-old woman with Guillain-Barre syndrome and persistent urinary retention 18 months following initial diagnosis. This patient is the first described in the literature to undergo successful treatment with sacral neuromodulation. Immediately following neuromodulator placement, the patient voided spontaneously and has had no voiding dysfunction or postvoid residual after 5 months of follow-up.
The binding properties of cyclophane dimers

Abstract Two water soluble cyclophane dimers have been prepared, and their binding properties examined. With a range of bidentate guests, the affinities of the new dimeric cyclophanes were similar to those of the monomeric analog.
CARBAMYL PHOSPHATE SYNTHESIS IN THE EARTHWORM LUMBRICUS TERRESTRIS

The enzymatic synthesis of citrulline from ammonia, bicarbonate, adenosine triphosphate, and L-ornithine takes place in the soluble fraction of gut tissue of the earthworm. The synthesis occurs at low ammonia concentrations, is dependent upon added N-acetyl-L-glutamate, and results in incorporation of the bicarbonate carbon into the ureido group of the citrulline molecule. Carbamyl phosphate is the intermediate in the reaction and its biosynthesis in the earthworm is mediated by a carbamyl phosphate synthetase system similar to that of ureotelic vertebrates.