cssi/SciSciGPT-SciSciNet huggingface dataset:
Methods to Address Confounding and Other Biases in Meta-Analyses: Review and Recommendations.

Meta-analyses contribute critically to cumulative science, but they can produce misleading conclusions if their constituent primary studies are biased, for example by unmeasured confounding in nonr...
Algorithmic Ethics: Formalization and Verification of Autonomous Vehicle Obligations

In this article, we develop a formal framework for automatic reasoning about the obligations of autonomous cyber-physical systems, including their social and ethical obligations. Obligations, permissions, and prohibitions are distinct from a system's mission, and are a necessary part of specifying advanced, adaptive AI-equipped systems. They need a dedicated deontic logic of obligations to formalize them. Most existing deontic logics lack corresponding algorithms and system models that permit automatic verification. We demonstrate how a particular deontic logic, Dominance Act Utilitarianism (DAU) [23], is a suitable starting point for formalizing the obligations of autonomous systems like self-driving cars. We demonstrate its usefulness by formalizing a subset of Responsibility-Sensitive Safety (RSS) in DAU; RSS is an industrial proposal for how self-driving cars should and should not behave in traffic. We show that certain logical consequences of RSS are undesirable, indicating a need to further refine the proposal. We also demonstrate how obligations can change over time, which is necessary for long-term autonomy. We then demonstrate a model-checking algorithm for DAU formulas on weighted transition systems and illustrate it by model-checking obligations of a self-driving car controller from the literature.
Helping Reduce Environmental Impact of Aviation with Machine Learning

Commercial aviation is one of the biggest contributors towards climate change. We propose to reduce environmental impact of aviation by considering solutions that would reduce the flight time. Specifically, we first consider improving winds aloft forecast so that flight planners could use better information to find routes that are efficient. Secondly, we propose an aircraft routing method that seeks to find the fastest route to the destination by considering uncertainty in the wind forecasts and then optimally trading-off between exploration and exploitation.
DocFormer: End-to-End Transformer for Document Understanding

We present DocFormer -- a multi-modal transformer based architecture for the task of Visual Document Understanding (VDU). VDU is a challenging problem which aims to understand documents in their varied formats (forms, receipts etc.) and layouts. In addition, DocFormer is pre-trained in an unsupervised fashion using carefully designed tasks which encourage multi-modal interaction. DocFormer uses text, vision and spatial features and combines them using a novel multi-modal self-attention layer. DocFormer also shares learned spatial embeddings across modalities which makes it easy for the model to correlate text to visual tokens and vice versa. DocFormer is evaluated on 4 different datasets each with strong baselines. DocFormer achieves state-of-the-art results on all of them, sometimes beating models 4x its size (in no. of parameters).
Local and distributed cortical markers of effort expenditure during sustained goal pursuit.

Abstract The adaptive adjustment of behavior in pursuit of desired goals is critical for survival. To accomplish this complex feat, individuals must weigh the potential benefits of a given action against time, energy, and resource costs. Here, we examine brain responses associated with willingness to exert physical effort during the sustained pursuit of desired goals. Our analyses reveal a distributed pattern of brain activity in aspects of ventral medial prefrontal cortex that tracks with trial-level variability in effort expenditure. Indicating the brain represents echoes of effort at the point of feedback, whole-brain searchlights identified signals reflecting past effort expenditure in medial and lateral prefrontal cortices, encompassing broad swaths of frontoparietal and dorsal attention networks. These data have important implications for our understanding of how the brain's valuation mechanisms contend with the complexity of real-world dynamic environments with relevance for the study of behavior across health and disease.
Co-Scale Conv-Attentional Image Transformers

In this paper, we present Co-scale conv-attentional image Transformers (CoaT), a Transformer-based image classifier equipped with co-scale and conv-attentional mechanisms. First, the co-scale mechanism maintains the integrity of Transformers' encoder branches at individual scales, while allowing representations learned at different scales to effectively communicate with each other; we design a series of serial and parallel blocks to realize the co-scale mechanism. Second, we devise a conv-attentional mechanism by realizing a relative position embedding formulation in the factorized attention module with an efficient convolution-like implementation. CoaT empowers image Transformers with enriched multi-scale and contextual modeling capabilities. On ImageNet, relatively small CoaT models attain superior classification results compared with similar-sized convolutional neural networks and image/vision Transformers. The effectiveness of CoaT's backbone is also illustrated on object detection and instance segmentation, demonstrating its applicability to downstream computer vision tasks.
PCMPC: Perception-Constrained Model Predictive Control for Quadrotors with Suspended Loads using a Single Camera and IMU

In this paper, we address the Perception– Constrained Model Predictive Control (PCMPC) and state estimation problems for quadrotors with cable suspended payloads using a single camera and Inertial Measurement Unit (IMU). We design a receding–horizon control strategy for cable suspended payloads directly formulated on the system manifold configuration space SE (3) ×S2. The approach considers the system dynamics, actuator limits and the camera’s Field Of View (FOV) constraint to guarantee the payload’s visibility during motion. The monocular camera, IMU, and vehicle’s motor speeds are combined to provide estimation of the vehicle’s states in 3D space, the payload’s states, the cable’s direction and velocity. The proposed control and state estimation solution runs in real-time at 500 Hz on a small quadrotor equipped with a limited computational unit. The approach is validated through experimental results considering a cable suspended payload trajectory tracking problem at different speeds.
Global conservation laws and femtoscopy of small systems

It is increasingly important to understand, in detail, two-pion correlations measured in $p+p$ and $d+A$ collisions. In particular, one wishes to understand the femtoscopic correlations to compare to similar measurements in heavy-ion collisions. However, in the low-multiplicity final states of these systems, global conservation laws generate significant $N$-body correlations that project onto the two-pion space in nontrivial ways and complicate the femtoscopic analysis. We discuss a formalism to calculate and account for these correlations in collisions dominated by a single particle species (e.g., pions). We also discuss effects on two-particle correlations between nonidentical particles, the understanding of which may be important in the study of femtoscopic space-time asymmetries.
The Distinguishing Number and Distinguishing Chromatic Number for Posets

In this paper we introduce the concepts of the distinguishing number and the distinguishing chromatic number of a poset. For a distributive lattice L and its set QL of join-irreducibles, we use classic lattice theory to show that any linear extension of QL generates a distinguishing 2-coloring of L. We prove general upper bounds for the distinguishing chromatic number and particular upper bounds for the Boolean lattice and for divisibility lattices. In addition, we show that the distinguishing number of any twin-free Cohen-Macaulay planar lattice is at most 2.
kPAM-SC: Generalizable Manipulation Planning using KeyPoint Affordance and Shape Completion

While traditional approaches to manipulation planning assume known object templates, recent approaches to "category-level manipulation" aim to manipulate a category of objects with potentially unknown instances and large intra-category shape variation. In this paper we explore an object representation to enable precise category-level manipulation, capturing a notion of the object configuration and extent, while being generalizable to novel instances. Building on our previous work, kPAM 1, we combine semantic keypoints with dense geometry (a point cloud or mesh) as the interface between the perception module and motion planner. Leveraging advances in learning-based keypoint detection and shape completion, both dense geometry and keypoints can be perceived from raw sensor input. Using the proposed hybrid object representation, we formulate the manipulation task as a motion planning problem which encodes both the object target configuration and physical feasibility for a category of objects. In this way, many existing manipulation planners can be generalized to categories of objects, and the resulting perception-to-action manipulation pipeline is robust to large intra-category shape variation. Extensive hardware experiments demonstrate our pipeline can produce robot trajectories that accomplish tasks with never-before-seen objects. The video demo is available on this link: https://sites.google.com/view/generalizable-manipulation.
Predictive feedback, early sensory representations and fast responses to predicted stimuli depend on NMDA receptors.

Learned associations between stimuli allow us to model the world and make predictions, crucial for efficient behavior; e.g., hearing a siren, we expect to see an ambulance and quickly make way. While there are theoretical and computational frameworks for prediction, the circuit and receptor-level mechanisms are unclear. Using high-density EEG, Bayesian modeling and machine learning, we show that inferred “causal” relationships between stimuli and frontal alpha activity account for reaction times (a proxy for predictions) on a trial-by-trial basis in an audio-visual delayed match-to-sample task which elicited predictions. Predictive beta feedback activated sensory representations in advance of predicted stimuli. Low-dose ketamine, a NMDA receptor blocker – but not the control drug dexmedetomidine – perturbed behavioral indices of predictions, their representation in higher-order cortex, feedback to posterior cortex and pre-activation of sensory templates in higher-order sensory cortex. This study suggests predictions depend on alpha activity in higher-order cortex, beta feedback and NMDA receptors, and ketamine blocks access to learned predictive information. SIGNIFICANCE STATEMENT: We learn the statistical regularities around us, creating associations between sensory stimuli. These associations can be exploited by generating predictions, which enable fast and efficient behavior. When predictions are perturbed, it can negatively influence perception and even contribute to psychiatric disorders such as schizophrenia. Here we show that the frontal lobe generates predictions and sends them to posterior brain areas, to activate representations of predicted sensory stimuli before their appearance. Oscillations in neural activity – alpha and beta waves – are vital for these predictive mechanisms. The drug ketamine blocks predictions and the underlying mechanisms. This suggests that the generation of predictions in the frontal lobe, and the feedback pre-activating sensory representations in advance of stimuli, depend on NMDA receptors.
Leaking Secrets through Modern Branch Predictor in the Speculative World

Transient-execution attacks that exploit speculation have raised significant concerns in computer systems. Typically, branch-predictors are leveraged to trigger mis-speculation in transient-execution attacks. In this work, we demonstrate a new class of speculation-based attack that targets branch-prediction unit. We find that speculative resolution of conditional branches alter the states of pattern-history table in modern processors, which are not restored after the corresponding branches are later squashed. Such characteristic allows attackers to exploit BPU as the secret transmitting-medium in transient-execution attacks. To evaluate the discovered vulnerability, we build a novel attack-framework, BranchSpectre, that enables unintended secrets exfiltration through observing speculative PHT updates. We further investigate PHT-collision mechanism in the history-based predictor as well as the branch-prediction mode transitions in Intel processors. We implement a covert-channel (BranchSpectre-cc) and two side channels (BranchSpectre-v1 and BranchSpectre-v2) that rely on BPU for mis-speculation trigger and secret inference in the speculative domain. Notably, BranchSpectre side channels take advantage of much simpler code patterns than the ones used in Spectre attacks. We present an extensive BranchSpectre code gadget analysis on several popular real-world application code-bases followed by a demonstration of real-world side-channel attack on OpenSSL. Finally, we discuss secure branch prediction mechanisms that can mitigate transient execution attacks.
Oncogenic KRAS requires complete loss of BAP1 function for development of murine intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a primary biliary malignancy that harbors a dismal prognosis. Oncogenic mutations of KRAS and loss-of-function mutations of BRCA1-associated protein 1 (BAP1) have been identified as recurrent somatic alterations in ICC. However, an autochthonous genetically engineered mouse model of ICC that genocopies the co-occurrence of these mutations has never been developed. By crossing Albumin-Cre mice bearing conditional alleles of mutant Kras and/or floxed Bap1, Cre-mediated recombination within the liver was induced. Mice with hepatic expression of mutant KrasG12D alone (KA), bi-allelic loss of hepatic Bap1 (BhomoA), and heterozygous loss of Bap1 in conjunction with mutant KrasG12D expression (BhetKA) developed primary hepatocellular carcinoma (HCC), but no discernible ICC. In contrast, mice with homozygous loss of Bap1 in conjunction with mutant KrasG12D expression (BhomoKA) developed discrete foci of HCC and ICC. Further, the median survival of BhomoKA mice was significantly shorter at 24 weeks when compared to the median survival of ≥40 weeks in BhetKA mice and approximately 50 weeks in BhomoA and KA mice (p < 0.001). Microarray analysis performed on liver tissue from KA and BhomoKA mice identified differentially expressed genes in the setting of BAP1 loss and suggests that deregulation of ferroptosis might be one mechanism by which loss of BAP1 cooperates with oncogenic Ras in hepato-biliary carcinogenesis. Our autochthonous model provides an in vivo platform to further study this lethal class of neoplasm.
Continuity, localization, and cosmology in warped geometry

This is the first of two papers studying localization of massive bulk fields on a bane in 5D anti-de Sitter spacetime, and some of their cosmological consequences. Here we focus on a massive 5D scalar, which is known to lack a localized mode, and discuss how a seeming discontinuity between this theory and the massless theory - known to support a localized zero mode - is resolved thanks to peculiar analytic properties of the massive two-point amplitude. Furthermore, we propose a boundary term that leads to the emergence of a massless localized mode in the massive theory. Last but not least, we consider the case when the brane world-volume is de Sitter spacetime, and prove the existence of a localized massive mode. We discuss how these results, taken collectively, can be used to describe the accelerated expansion due to the massive 5D scalar field in an early, or in a late-time universe.
Control Barrier Functions With Unmodeled Dynamics Using Integral Quadratic Constraints.

This paper presents a control design method that achieves safety for systems with unmodeled dynamics at the plant input. The proposed method combines control barrier functions (CBFs) and integral quadratic constraints (IQCs). Simplified, low-order models are often used in the design of the controller. Parasitic, unmodeled dynamics (e.g. actuator dynamics, time delays, etc) can lead to safety violations. The proposed method bounds the input-output behavior of these unmodeled dynamics in the time-domain using an alpha-IQC. The alpha-IQC is then incorporated into the CBF constraint to ensure safety. The approach is demonstrated with a simple example.
Trust-Aware Emergency Response for A Resilient Human-Swarm Cooperative System

A human-swarm cooperative system, which mixes multiple robots and a human supervisor to form a mission team, has been widely used for emergent scenarios such as criminal tracking and victim assistance. These scenarios are related to human safety and require a robot team to quickly transit from the current undergoing task into the new emergent task. This sudden mission change brings difficulty in robot motion adjustment and increases the risk of performance degradation of the swarm. Trust in human-human collaboration reflects a general expectation of the collaboration; based on the trust humans mutually adjust their behaviors for better teamwork. Inspired by this, in this research, a trust-aware reflective control (Trust-R), was developed for a robot swarm to understand the collaborative mission and calibrate its motions accordingly for better emergency response. Typical emergent tasks “transit between area inspection tasks”, “response to emergent target - car accident” in social security with eight fault-related situations were designed to simulate robot deployments. A human user study with 50 volunteers was conducted to model trust and assess swarm performance. Trust-R's effectiveness in supporting a robot team for emergency response was validated by improved task performance and increased trust scores.
Prognostic Values of Preoperative Findings for Diabetic Vitrectomy

Recommending vitrectomy, like any surgical procedure, requires that the probable results of the vitrectomy are better than other forms of treatment or the natural course of the disease. To better predict the results of vitrectomy for diabetic retinopathy complications, various previtrectomy findings were compared with the 6 month visual results.
Law and Development: The Chilean Housing Program

Study of the role of law in development has lagged for a number of reasons. Non-lawyers tend to think of law as criminal law and court rooms. Furthermore, they dismiss law as irrelevant with the facile observation that law is useless if the government is not sincere in enforcing it. This, of course, is true also of economic policy or regional planning. One cannot help but wonder why law should be held to a higher standard.
Evolution as a guide for autonomous vehicle path planning and coordination

Influenced by the problem-solving capability observed in nature, we utilize the mechanism of simulated evolution as the basis for path-planning algorithms for uninhabited vehicles. An attractive feature of evolution-based search is the general nature of performance criteria that can be defined, incorporating both continuous and discrete measures of candidate solutions. These criteria can often be defined as straightforward mathematical realizations of "fuzzy" objectives, consistent with the use of natural language syntax and dialogue. This paper investigates the influence of the population representation on the efficacy of solution of a series of static path planning problems of increasing complexity. Furthermore, we demonstrate the potential for solving mission planning problems at higher levels of abstraction by extending the evolution-based formulation to handle coordination of multiple vehicles. We apply this framework to a multiple traveling salesperson problem in which the vehicles work together to accomplish goals with respect to an overall team performance metric.
Probabilistic Earthquake Energy Spectra Equations

The response of a lightly damped linear structure to a broad-band nonstationary random process with evolutionary spectral density is considered. A first-order stochastic differential equation governing the time evolution of the structural energy is derived. Utilizing this equation a readily applicable equation for the determination of the mean energy is obtained. Nonstationary random processes proposed in the literature for the simulation of earthquakes are examined in detail, and equations for the construction of probabilistic energy spectra are presented.
Event based synchronization between motion signal and video frames

Focusing on the problem that collected modulating signals and video signals couldn't match well which occurs in the testing procedure of intelligent vehicles, we put forward a new method to achieve signal synchronization based on the optimal matching of gyroscope signals and video information. We use the metrical information of gyroscope produced during the operation of intelligent vehicles as an accurate observation of signal time compared with the pseudo-trajectory processing information of video which happened in the same time quantum to do the optimal matching and achieve the accurate synchronization of video and modulated signals in intelligent vehicles. Firstly, using video signals to do the location and trajectory analysis of intelligent vehicles. Secondly, using Kaiman filtering to deal with the track and taking forecast error as the testing basis of matching event. Lastly, doing optimal matching between the time point and gyro signal when the event happens and achieving the accurate synchronization of signal. The experimental result shows that this method is easy to carry out and won't cost too much. It doesn't require strict debugging system but works with high accuracy. It is of high value in the researching, tuning and competing of intelligent vehicles.
Sea-surface salinity fronts and associated salinity-minimum zones in the tropical ocean

The Intertropical Convergence Zone (ITCZ) is a major source of the surface freshwater input to the tropical open ocean. Under the ITCZ, sea-surface salinity (SSS) fronts that extend zonally across the basins are observed by the Aquarius/SAC-D mission and Argo floats. This study examined the evolution and forcing mechanisms of the SSS fronts. It is found that, although the SSS fronts are sourced from the ITCZ-freshened surface waters, the formation, structure, and propagation of these fronts are governed by the trade wind driven Ekman processes. Three features characterize the governing role of Ekman forcing. First, the SSS fronts are associated with near-surface salinity-minimum zones (SMZs) of 50–80 m deep. The SMZs are formed during December–March when the near-equatorial Ekman convergence zone concurs with an equatorward displaced ITCZ. Second, after the formation, the SMZs are carried poleward away at a speed of ∼3.5 km d−1 by Ekman transport. The monotonic poleward propagation is a sharp contrast to the seasonal north/south oscillation of the ITCZ. Lastly, each SMZ lasts about 12–15 months until dissipated at latitudes beyond 10°N/S. The persistence of more than 1 calendar year allows two SMZs to coexist during the formation season (December–March), with the newly formed SMZ located near the equator while the SMZ that is formed in the previous year located near the latitudes of 10–15° poleward after 1 year's propagation. The contrast between the ITCZ and SMZ highlights the dominance of Ekman dynamics on the relationship between the SSS and the ocean water cycle.
A Unified Approach to Submicron DC MOS Transistor Modeling for Low-Voltage ICs

A unified single-equation approach for the MOS transistor drain current modeling for energy-efficient submicron MOS circuits is presented. Instead of three sets of separate equations for the triode, saturation, and weak inversion regions, only a continuous expression which is valid to describe the behavior of drain current and the derivatives in all operation regions can be realized by using a combination of hyperbola, sigmoid, and interpolation methods. The model expression can predict accurate results for the current, output conductance, and transconductance with continuous and smooth characteristics. The simulation results agree well with experimental data.
The correlation between strength and the rate of tension development of a static muscular contraction

Twenty-five young adult male subjects twice squeezed a hand ergograph as rapidly and with as much force as possible, each effort being recorded on fast-moving-paper. A succession of measurements were made along the force-time curves and the data individually fitted to a single component exponential equation. The correlation between maximal force and the time required to reach a criterion value (30 kg.) was high (r= −.85); the stronger the individual the more quickly he reached this goal. On the other hand, the correlation between maximum strength and the rate of change of the contraction was approximately zero (r=−.03), indicating that the pattern of development of muscular force is highly task specific. This supports the concept that such abilities are determined by separate neuromuscular coordination pathways of the central nervous system.
Prion protein (PrPc) positively regulates neural precursor proliferation during developmental and adult mammalian neurogenesis

The misfolding of the prion protein (PrPc) is a central event in prion diseases, yet the normal function of PrPc remains unknown. PrPc has putative roles in many cellular processes including signaling, survival, adhesion, and differentiation. Given the abundance of PrPc in the developing and mature mammalian CNS, we investigated the role of PrPc in neural development and in adult neurogenesis, which occurs constitutively in the dentate gyrus (DG) of the hippocampus and in the olfactory bulb from precursors in the subventricular zone (SVZ)/rostral migratory stream. In vivo, we find that PrPc is expressed immediately adjacent to the proliferative region of the SVZ but not in mitotic cells. In vivo and in vitro studies further find that PrPc is expressed in multipotent neural precursors and mature neurons but is not detectable in glia. Loss- and gain-of-function experiments demonstrate that PrPc levels correlate with differentiation of multipotent neural precursors into mature neurons in vitro and that PrPc levels positively influence neuronal differentiation in a dose-dependent manner. PrPc also increases cellular proliferation in vivo; in the SVZ, PrPc overexpresser (OE) mice have more proliferating cells compared with wild-type (WT) or knockout (KO) mice; in the DG, PrPc OE and WT mice have more proliferating cells compared with KO mice. Our results demonstrate that PrPc plays an important role in neurogenesis and differentiation. Because the final number of neurons produced in the DG is unchanged by PrPc expression, other factors must control the ultimate fate of new neurons.
A Comparison of Some Cellular and Chemical Constituents of Blood at Time of Parturition and after Administration of Adrenocorticotrophin

Summary A comparison was made of the reaction of leucocytes and blood sugar to parturition and to the administration of 250 I.U. of ACTH. The stress of parturition caused a diminution in the per cent of circulating lymphocytes and eosinophils and an increment in the neutrophils and blood sugar. Administration of ACTH also caused a diminution in the per cent of circulating lymphocytes and eosinophils and an increment in the neutrophils and blood sugar. Generally the magnitude of change was greater from the dose of ACTH administered than from the stimulus of parturition. The results of this study indicate an increased secretion from the adrenal cortex in response to the stress of parturition in the cow.
Lack of dihydrofolate reductase activity in brain tissue of mammalian species: possible implications.

IT IS becoming increasingly clear that folates play a vital, yet until recently an unrecognized, role in the development and function of the brain. Thus several groups of patients have been found with severe maldevelopment of the brain and mental retardation associated with inborn errors of folate metabolism resulting from congenital deficiency in one or more enzymes involved in folate metabolism (ARAKAWA et al., 1965; 1966; 1967; MUDD, LEVY and ABELES, 1969; ARAKAWA, 1970). The presence of folate coenzymes in brain tissue has been reported by several investigators (ALLEN and KLIPSTEIN, 1970; MCCLAIN and BRIDGERS, 1969). MCCLAIN and BRIDGERS (1969) showed that much less of the folates in brain are in the form of the N5-methyl derivatives than is the case for folates in plasma, red blood cells and liver. Appreciable activity of several folate interconverting enzymes have been demonstrated in brain tissue; for example, N5-methyl tetrahydrofolate homocysteine methyl transferase has been found to exist in higher levels in brain than in liver or kidney (MANGUM, 1972); N5-methyl FH,N-dimethyl-dopamine methyl transferase (LADURON, 1972) and serine transhydroxymethylase (EC 2.1.1; L-Serine: tetrahydrofolate 5, 10-hydroxymethyl transferase) (BRIDGERS, 1968) have recently been detected in brain. The last enzyme is known to catalyse a reaction responsible for the generation of a major portion of one-carbon units. In mouse brain, the activity of this enzyme declines during the first 2 weeks of extra-uterine life (BRIDGERS, 1968). The aim of the present study was to determine the levels of dihydrofolate reductase(5,6,7,8-tetrahydrofolate:NADP+ oxidoreductase; EC 1.5.1.3) in mammalian brain tissues in comparison to the levels in other tissues. This enzyme occupies the first and key position in folate metabolism, reducing the metabolically inert vitamin, folic acid, to tetrahydrofolate. This enzyme also functions in thymidylate synthesis to regenerate tetrahydrofolate from dihydrofolate, a product of the reaction (HWHREYS and GREENBERG, 1958). In this reduced state the molecule can accept one-carbon units from various sources to give rise to metabolically active coenzyme forms of folate. This communication reports the complete absence of dihydrofolate reductase in brain tissue of several mammalian species.
Sol-gel derived Pb(Sc0.5Ta0.5)O3 powders

Abstract Phase pure ferroelectric relaxor Pb(Sc 0.5 Ta 0.5 )O 3 perovskite (PST) has been synthesized using metal organic precursors including Pb(CH 3 COO) 2 · 3H 2 O, Sc(CH 3 COO) 3 · x H 2 O and Ta(OC 2 H 5 ) 5 . This method of synthesizing PST powders yields phase pure PST and the present route via organic precursors is much simpler in contrast to the earlier reported approaches.
Inhibitory effect of 2″-O-glycosyl isovitexin and α-tocopherol on genotoxic glyoxal formation in a lipid peroxidation system

The inhibitory effect of 2"-O-glycosyl isovitexin (2"-O-GIV), isolated from young barley leaves, on glyoxal formation from the oxidative degradation of three fatty acid ethyl esters was measured. Ethyl linoleate, ethyl linolenate and ethyl arachidonate were oxidized by Fenton's reagent. Glyoxal formed from these fatty acid esters was analysed by gas chromatography after it had been derivatized to quinoxaline with 1,2-phenylenediamine. The comparative study was performed using alpha-tocopherol. Generally, alpha-tocopherol exhibited a greater inhibitory effect at lower levels, whereas 2"-O-GIV showed a greater effect than alpha-tocopherol at higher levels. 2"-O-GIV was more effective than alpha-tocopherol towards fatty acid esters with high numbers of double bonds. 2"-O-GIV exhibited a dose-response effect but alpha-tocopherol did not. Maximum inhibition of 82% was obtained from oxidation of ethyl arachidonate at 8 mumol 2"-O-GIV, whereas maximum inhibition of 77% was observed from oxidation of ethyl arachidonate at 0.25 mumol alpha-tocopherol.
High risk blood pressure and obesity increase the risk for left ventricular hypertrophy in African-American adolescents.

Objective To examine the relative effects of high blood pressure (HBP) and obesity on left ventricular mass (LVM) among African-American adolescents; and if metabolic or inflammatory factors contribute to LVM. Study design Using a 2 × 2 design, African-American adolescents were stratified by body mass index percentile (body mass index Results Data included 301 adolescents (48% female), mean age 16.2 years, 51% obese, and 29% HBP. LVMI was highest among adolescents with both obesity and HBP. The multiplicative interaction of obesity and HBP on LVH was not significant (OR = 2.35, P = .20) but the independent additive associations of obesity and HBP with log-odds of LVH were significant; obesity OR = 3.26, P P 2.7 , P P Conclusions Prevalence of LVH is highest among African-American adolescents with average BP ≥120/80 mm Hg and obesity. There also is an independent association of LVMI with BP, beginning at the 75th SBP percentile.
Protein kinase-mediated reciprocal modulatory changes in anesthetic sensitivity of (BK)-K+- and GABA-A receptor-gated conductances in guinea-pig sympathetic neurons.

Abstract (1) The interaction of substance P (SP)-mediated synaptic transmission with general anesthetics remains unknown. (2) Intracellular recordings were obtained from guinea-pig inferior mesenteric ganglion neurons to study monosynaptic responses to exogenous SP and GABA. (3) Propofol (1–100 μ M) caused an increase in SP-evoked inward current responses and a concurrent decrease in peak amplitude of the afterspike hyperpolarization of intermittently evoked action potentials. These effects were occluded by the (BK)-K + -channel-selective blocker charybdotoxin (10 nM), and prevented by the protein kinase inhibitor staurosporine (100 nM). (4) Propofol also increased GABA-evoked current ( I GABA ) responses. (5) When elicited during a SP response, I GABA was significantly diminished compared to control. In the presence of staurosporine (100 nM), the inhibitory effect of SP upon I GABA was abolished, and the propofol-induced augmentation of I GABA was significantly increased. (6) Thus, SP-evoked protein kinase activity produced reciprocal changes in anesthetic sensitivity of (BK)-K + - and GABA A-receptor-gated currents of these sympathetic neurons.
Application of multidimensional scaling to ratings of foods for obese and normal weight individuals.

Abstract Sixteen obese patients, aged 19–31, and 27 normal weight individuals, aged 18–22, tasted and smelled fresh, unseasoned blended foods while blindfolded. Then they rated the foods on 51 semantic differential adjective scales which related to stimulation of the gustatory, olfactory, and trigeminal systems. The stimuli included fruits, vegetables, meat, fish, nuts, dairy products, grains, and a set of four standards: sucrose (sweet), NaCl (salty), lemon (sour), and coffee (bitter) in a thin cornstarch base. Proximity measures among stimuli for each subject were developed from the ratings on the adjective scales. Two multidimensional scaling (MDS) procedures, SINDSCAL (a variation of INDSCAL) and ALSCAL, were applied to the proximity measures yielding two-dimensional food maps which were very similar. Both MDS procedures provided weights for each subject on the two dimensions of the space common for all subjects. The weights indicated that the obese subjects found the first dimension, which was related to the hedonic and flavorous aspects of the stimuli, relatively more important than normal weight individuals. Also, obese subjects were significantly better at identifying the blended foods when compared to normal weight subjects.
Magnetoencephalography of Epilepsy with a Microfabricated Atomic Magnetrode

Magnetoencephalography has long held the promise of providing a noninvasive tool for localizing epileptic seizures in humans because of its high spatial resolution compared with the scalp EEG. Yet, this promise has been elusive, not because of a lack of sensitivity or spatial resolution but because the large size and immobility of present cryogenic (superconducting) technology prevent long-term telemetry required to capture these very infrequent epileptiform events. To circumvent this limitation, we used Micro-Electro-Mechanical Systems technology to construct a noncryogenic (room temperature) microfabricated atomic magnetometer (“magnetrode”) based on laser spectroscopy of rubidium vapor and similar in size and flexibility to scalp EEG electrodes. We tested the magnetrode by measuring the magnetic signature of epileptiform discharges in a rat model of epilepsy. We were able to measure neuronal currents of single epileptic discharges and more subtle spontaneous brain activity with a high signal-to-noise ratio approaching that of present superconducting sensors. These measurements are a promising step toward the goal of high-resolution noninvasive telemetry of epileptic events in humans with seizure disorders.
Estimating Consumption Parameters for Food Policy Analysis

Food policy analysis links nutrition objectives to macroeconomic policies and performance. At the heart of the analysis is a matrix of price and income elasticities that must be incomestrata-specific. Obtaining this matrix for aggregated income classes requires a blend of complex theory and sophisticated econometric analysis that is only possible with restrictive assumptions about the separability of the impact of price changes for one commodity class on changes in demand for other commodity groups. The separability assumptions are not overly restrictive in the context of such highly aggregated commodities as food, housing, or clothing. But when important nutritional effects occur due to substitution of one quality of wheat for another, or the substitution of cassava for rice, then the level of commodity detail needed to reproduce accurately the impact of relative price changes forecloses the "econometric" approach even for combined income classes. Obtaining the full matrix for disaggregated income classes requires a new approach and this paper reports one attempt.
Eating late in the evening is associated with childhood obesity in some age groups but not in all children: the relationship between time of consumption and body weight status in U.S. children

Some studies in adults indicate a positive correlation between eating later in the day and overall energy intake as well as body weight status. Thus, the time of food intake may be a risk factor in childhood obesity. This study was designed to describe the proportion of energy consumed in the time from 4 pm to midnight measured in two-hour increments and to determine a potential association between the time of proportion of energy consumed and body weight status. Dietary, anthropometric, and socio-demographic data of 2–18 year olds (N = 11,072) of the National Health and Nutrition Examination Survey (NHANES) 1999–2004 was examined to describe the proportion of total energy consumed within two-hour time periods between 4 pm and midnight. To examine the potential association between eating later in the day and body weight status, generalized estimating equations (GEE) models were used to quantify the effect of time trends (proportion of total energy consumed in each 2-hour time period from 4 pm to 11.59 pm) on body weight status. Analysis was conducted in the total sample and in subgroups stratified by sex, ethnic group (Non-Hispanic white, Non-Hispanic black, Mexican American, Other Hispanic, and Other Race including multi-racial) and age group (2–5, 6–11, and 12–18 year olds). Complex sample survey analysis were used to assess differences at a significance level of p-value < 0.05. Proportion of energy consumed varied by sex, ethnic group, and age groups between 4 pm and 11.59 pm. Compared to healthy weight children, overweight school-age children consumed significantly higher while overweight adolescents consumed significantly lower proportions of total daily energy with each advancing two-hour time increment. The association between the circadian rhythm of eating and body weight status needs to be investigated further to examine the effect of time of consumption on the risk of childhood obesity. Especially longitudinal studies in diverse child populations would help elucidate the importance of time of eating on obesity.
More on Mount St. Helens

Mount St. Helens Volcano, Cascade Range, Southern Washington, U.S.A. (46.20°N, 122.18°W). All times are local (GMT-7 hours). The devastating May 18th eruption of Mount St. Helens was followed by explosions on May 25 and June 12 that were much smaller but produced substantial ashfalls over wide areas of Oregon and Washington. A series of explosions ejected tephra from Mount St. Helens during the evening of July 22, nearly 6 weeks after the June 12 activity. Eruption cloud heights were similar to those of May 25 and June 12, but ashfall thicknesses were significantly less.
General Surgical Laparoscopic Procedures for the “Nonlaparologist”

Objective To assess our initial experience with a variety of laparoscopic procedures that can be performed by general surgeons with the basic skills used for laparoscopic cholecystectomy and without advanced laparoscopic expertise. Material and Methods We retrospectively reviewed a 36-month experience (1991 through 1994) at our institution with a consecutive series of patients who underwent basic laparoscopic surgical procedures but specifically excluding cholecystectomy, appendectomy, herniorrhaphy, and colectomy. Results Procedures performed laparoscopically included gastrostomy, jejunostomy, small bowel resection, intra-abdominal and retroperitoneal biopsy, staging of intra-abdominal malignant lesions, and adhesiolysis for relief of small bowel obstruction. During the 3-year study period, 106 patients underwent 107 procedures, 89 of which were successful. Four patients had substantial complications, two of whom underwent surgical repair. Conclusion A spectrum of procedures may be safely performed with the skills learned from laparoscopic cholecystectomy and without the need for advanced laparoscopic skills such as intracorporeal suturing or tying of knots.
Chemical, physical and biological changes associated with chara succession in farm ponds

Four farm ponds in various stages of Chara vulgaris succession -from the initial invasion of the alga to its nearly complete replacement-were followed each week from ice cover to ice cover. Chemical, physical, and biological parameters were analyzed in order to determine differences between ponds and to discover the biological and physicochemical factors associated with succession in Chara vulgaris ponds. The data were analyzed statistically by intraclass (single factor) analysis of variance, the Student's t-test, and stepwise multiple regression analysis. The initial invasion of C. vulgaris appeared to be preceded by a lowering of the nutrient levels of the pond by Zygnematales growth and by the substrate-stabilizing growth of Rhizoclonium sp. Chara-dominated ponds had significantly lower free CO2, bicarbonate alkalinity, and total hardness readings. Carbonate alkalinity, low phytoplankton productivity, high dissolved O2, low phosphate, and high Secchi disk readings were also characteristic of ponds in which C. vulgaris was dominant. In ponds where C. vulgaris appeared in the process of being replaced, the physicochemical factors were more closely associated with phytoplankton productivity and diversity and less closely with submerged vegetation species. Succession from C. vulgaris domination to a Najas-Potamogeton community appeared to involve shading of the former by the latter and was accelerated by the smothering effect of decaying debris caused by Gloeotrichia sp. In the final stages of succession, turbid conditions resulting from the lack of substrate-stabilizing vegetation and increased phytoplankton growth appear to have discouraged C. vulgaris growth early in the season.
A framework for the comparative analysis and evaluation of knowledge representation schemes

Abstract This article sets forth a framework for comparing and evaluating knowledge representation schemes based on the requirements for “good” representation discussed in extant literature. The dimensions of the framework suggest that knowledge representation schemes should possess a suitable mix of four basic considerations: Representational adequacy (Variety of Expressiveness, Modularity, Semantics, and Organization of Knowledge); Inference Methods (Reasoning Strategies, Data, Control and Search Strategies); and Inference Requirements (Computational Efficiency, Transparency of line of control, Completeness, and Consistency). A comparative analysis and evaluation of four popular knowledge representation schemes—Logic, Production Rules, Semantic Nets, Frames—highlighting their strengths and weaknesses in the context of the framework is furnished as evidence of its inherent validity and usefulness. In conclusion, it is submitted that incorporating an appropriate blend of the various dimensions elucidated in this article could be a step towards developing more flexible, dynamic, and valuable knowledge representation schemes.
Non-neuronal cell cultures from dorsal root ganglia of the adult cat: production of schwann-like cell lines

Summary There are several methods available for the production of Schwann cell cultures from fetal or neonatal peripheral nervous tissue. We have investigated methods for producing Schwann cell-rich cultures from adult tissue. Dorsal root gangliafrom normal adult cats were used to initiate explant cultures or subjected to primary dissociation. The resulting cultures were compared in terms of growth, the proportions of fibroblastic and Schwann-like cells in primary cultures and the effects of subculture on the relative frequency of these cell types. We found that excision and transfer of explanted ganglion pieces after 14 days in culture produced a secondary outgrowth rich in small, bipolar, spindle-shaped Schwann-like cells. Subculture of this outgrowth produced secondary cultures of predominantly SChwann-like cells with typical spindle-shaped morphology. The use of antimitotic agents in the media to inhibit fibroblast growth was not observed to be necessary or beneficial with this adult tissue. Primary dissociation of ganglia with enzymes (trypsin or collagenase) and mechanical agitation was even more effective in producing secondary cultures and cell lines that were, by morphological criteria, predominantly or exclusively Schwann-like cells. One of these Schwann-like cell lines, designated GSA, has been carried over 24 subcultures while retaining characteristics Schwann cell morphology. Cells of this line have been examined by scanning and transmission electron microscopy. Karyotype analysis indicates a chromosome complement consistent with the species of origin, a normal cat.
Crime and the decline of manufacturing, 1970–1990

The effects of the decline in manufacturing jobs in the 100 largest cities in the United States during the period from 1970 to 1990 are examined. It is hypothesized that cities which experienced the greatest losses would also suffer the greatest increases in poverty and unemployment. The elevation of poverty and the decrease in employment, in turn, would produce an increase in crime rates. All measures reflect the change over the period considered. The findings support the effects of reduced manufacturing on increased poverty and unemployment, but the correlations between the increase in poverty and the elevation of crime rates are negligible. The combination of the decline in manufacturing and the increase in unemployment is correlated with increases in economic crimes: robberies, burglaries, and arrests for drug offenses. The rates for larceny, murder, and aggravated assaults are not correlated with the decrease in manufacturing and the increase in unemployment.