cssi/SciSciGPT-SciSciNet huggingface dataset:
Autonomous Navigation of an Agricultural Robot Using RTK GPS and Pixhawk

This paper discusses the design, implementation, and performance of an autonomous navigation system built for an agricultural robot. The onboard precision GPS system allows the robot to navigate to potato plants previously identified as infected with Potato Virus Y (PVY), in order to remove them from the field efficiently. This autonomous robot is in-line with emerging technologies in the field of precision agriculture. The navigation system is based on a Pixhawk microcontroller for ease of use and affordability. Because only sick plants must be removed, an RTK GPS module from Swift Navigation was used to maximize accuracy. The supporting components, both electrical and mechanical, are covered in detail. This includes communication equipment, motors, and an enclosure to protect the components from weather and terrain. This AGV will serve as a test platform for sensors and grasping mechanisms that will eventually be integrated on a larger, more advanced, final version.
Path and Directionality Discovery in Individual Dynamic Models: A Regularized Unified Structural Equation Modeling Approach for Hybrid Vector Autoregression

There recently has been growing interest in the study of psychological and neurological processes at an individual level. One goal in such endeavors is to construct person-specific dynamic assessments using time series techniques such as Vector Autoregressive (VAR) models. However, two problems exist with current VAR specifications: (1) VAR models are restricted in that contemporaneous relations are typically modeled either as undirected relations among residuals or directed relations among observed variables, but not both; (2) current estimation frameworks are limited by the reliance on stepwise model building procedures. This study adopts a new modeling approach. We first extended the current unified SEM (uSEM) framework, a widely used structural VAR model, to a hybrid representation (i.e., “huSEM”) to include both undirected and directed contemporaneous effects, and then replaced the stepwise modeling with a LASSO-type regularization for a global search of the optimal sparse model. Our simulation study showed that regularized huSEM performed uniformly the best over alternative VAR representations and/or modeling approaches, with respect to accurately recovering the presence and directionality of hybrid relations and reliably removing false relations when the data are generated to have two types of contemporaneous relations. The present study to our knowledge is the first application of the recently developed regularized SEM technique to the estimation of huSEM, which points to a promising future for statistical learning in psychometric models.
A Layered Approach for Modular Container Construction and Orchestration in HPC Environments

Large-scale, high-throughput computational science faces an accelerating convergence of software and hardware. Software container-based solutions have become common in cloud-based datacenter environments, and are considered promising tools for addressing heterogeneity and portability concerns. However, container solutions reflect a set of assumptions which complicate their adoption by developers and users of scientific workflow applications. Nor are containers a universal solution for deployment in high-performance computing (HPC) environments which have specialized and vertically integrated scheduling and runtime software stacks. In this paper, we present a container design and deployment approach which uses modular layering to ease the deployment of containers into existing HPC environments. This layered approach allows operating system integrations, support for different communication and performance monitoring libraries, and application code to be defined and interchanged in isolation. We describe in this paper the details of our approach, including specifics about container deployment and orchestration for different HPC scheduling systems. We also describe how this layering method can be used to build containers for two separate applications, each deployed on clusters with different batch schedulers, MPI networking support, and performance monitoring requirements. Our experience indicates that the layered approach is a viable strategy for building applications intended to provide similar behavior across widely varying deployment targets.
Ubiquitylation and proteasomal degradation of the p21Cip1, p27Kip1 and p57Kip2 CDK inhibitors

The expression levels of the p21Cip1 family CDK inhibitors (CKIs), p21Cip1, p27Kip1 and p57Kip2, play a pivotal role in the precise regulation of cyclin-dependent kinase (CDK) activity, which is instrumental to proper cell cycle progression. The stabilities of p21Cip1, p27Kip1 and p57Kip2 are all tightly and differentially regulated by ubiquitylation and proteasome-mediated degradation during various stages of the cell cycle, either in steady state or in response to extracellular stimuli, which often elicit site-specific phosphorylation of CKIs triggering their degradation.
5-Keto-d-fructose IV. A SPECIFIC REDUCED NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE-LINKED REDUCTASE FROM GLUCONOBACTER CERINUS

Abstract A specific reduced nicotinamide adenine dinucleotide phosphate-linked 5-keto-d-fructose reductase has been isolated and purified approximately 1200-fold from extracts of Gluconobacter cerinus. The reaction catalyzed was found to be 5-Keto-d-fructose + NADPH + H+ ⇌ d-fructose + NADP+ with an equilibrium far towards the right (Keq = 2 x 1010). Km values for NADPH, NADP+, 5-ketofructose, and fructose were 1.8 x 10-6 m; 1.3 x 10-3 m; 4.5 x 10-3 m; and 7.0 x 10-2 m, respectively, at pH 7.4.
ADP-ribosylation factor is required for vesicular trafficking between the endoplasmic reticulum and the cis-Golgi compartment

We describe the potential role of ADP-ribosylation factor (ARF) in vesicular trafficking using an in vitro assay that efficiently reconstitutes transport between the endoplasmic reticulum (ER) and the cis-Golgi compartment in mammalian semi-intact cells, a population of cells in which the plasma membrane is physically perforated to reveal intact ER and Golgi compartments. We demonstrate that peptides identical to the amino-terminal domain of ARF, which inhibit ARF cofactor activity in cholera toxin-catalyzed ADP-ribosylation of G alpha S (Kahn, R. A., Randazzo, P., Serafini, T., Weiss, O., Rulka, C., Clark, J., Amherdt, M., Roller, P., Orci, L., and Rothman, J. E. (1992) J. Biol. Chem. 267, 13039-13046), inhibit transport of the vesicular stomatitis virus G protein between the ER and cis-Golgi compartment. Inhibition of transport was rapid (t1/2 = 30-60 s) and irreversible. Half-maximal inhibition was observed at concentrations of 15 and 22 microM with peptides identical to the amino-terminal domain of the human ARF4 (hARF4) protein and the human ARF1 protein, respectively. Kinetic analysis of vesicular stomatitis virus G protein transport suggested that the hARF4 peptide inhibits a late vesicle fusion step. In addition, incubation of semi-intact cells in the presence of the myristoylated form human ARF1 (hARF1myr) protein, but not the nonmyristoylated form of ARF1, inhibited transport. In contrast to peptide, the hARF1myr blocked an early transport step, similar to that observed with guanosine 5'-3-O-(thio)triphosphate. These results suggest that ARF and components facilitating ARF function play an important role in the cyclical fission and fusion of transport vesicles mediating ER to Golgi trafficking.
A Mathematical Model of Uncertain Information

This paper introduces a mathematical evidence model for uncertain information in artificial intelligence. Each evidence model contains prior information as well as possible new evidence to appear later. Both Bayesian probability distribution and Dempster-Shafer's ignorance are special evidence models. A concept of independence is also introduced. Dempster-Shafer's combination rule becomes a formula to combine basic probabilities of independent models.
Soft Tissue and Prosthetic Device Infections

Soft tissue infections can occur in any host when a microorganism is introduced accidentally into these tissues. Prostheses and medical devices predispose the patient to infections due to their foreign body effects that disrupt anatomic integrity and favor microbial entry, colonization, or attachment to the device in all hosts, whether they are immunocompromised or not. The interaction between the host and the microorganism determines whether infection takes place, its course, and its outcome. At the opposite ends of this delicate balance, rare but highly virulent microorganisms, such as Yersinia pestis, Bacillus anthracis, and Francisella tularensis, can strike any host, while common, minimally virulent microbes may infect only the most vulnerable hosts, such as those with immature or defective immune functions or those with prostheses or medical devices. Intravascular catheters provide a window to the bloodstream or to a target organ (such as the heart), where hemodynamics or organ functions may be measured and therapeutic drugs, nutrients, and radiological contrast materials are delivered. Patients with prosthetic devices, cancer, or other immune defects or weakness are prone to various skin and soft tissue infections.
A dosimetric evaluation of VMAT for the treatment of non-small cell lung cancer

The purpose of this study was to demonstrate the dosimetric potential of volumetric-modulated arc therapy (VMAT) for the treatment of patients with medically inoperable stage I/II non-small cell lung cancer (NSCLC) with stereotactic body radiation therapy (SBRT). Fourteen patients treated with 3D CRT with varying tumor locations, tumor sizes, and dose fractionation schemes were chosen for study. The prescription doses were 48 Gy in 4 fractions, 52.5 Gy in 5 fractions, 57.5 Gy in 5 fractions, and 60 Gy in 3 fractions for 2, 5, 1, and 6 patients, respectively. VMAT treatment plans with a mix of two to three full and partial noncoplanar arcs with 5°-25° separations were retrospectively generated using Eclipse version 10.0. The 3D CRT and VMAT plans were then evaluated by comparing their target dose, critical structure dose, high dose spillage, and low dose spillage as defined according to RTOG 0813 and RTOG 0236 protocols. In the most dosimetrically improved case, VMAT was able to decrease the dose from 17.35 Gy to 1.54 Gy to the heart. The D(2cm) decreased in 11 of 14 cases when using VMAT. The three that worsened were still within the acceptance criteria. Of the 14 3D CRT plans, seven had a D(2cm) minor deviation, while only one of the 14 VMAT plans had a D(2cm) minor deviation. The R(50%) improved in 13 of the 14 VMAT cases. The one case that worsened was still within the acceptance criteria of the RTOG protocol. Of the 14 3D CRT plans, seven had an R(50%) deviation. Only one of the 14 VMAT plans had an R(50%) deviation, but it was still improved compared to the 3D CRT plan. In this cohort of patients, no evident dosimetric compromises resulted from planning SBRT treatments with VMAT relative to the 3D CRT treatment plans actually used in their treatment.
Preservation of Serratia marcescens by High-Vacuum Lyophilization

Water-washed Serratia marcescens (ATCC strain 14041) cells were lyophilized in an all-glass system capable of evacuation to pressures of less than 5 × 10-6 torr. Lyophilization at the lowest pressures resulted in 50 to 65% survival for unstabilized washed organisms compared with 10 to 20% when the cells were lyophilized at pressures of about 2.5 × 10-2 torr. At the latter pressures, 45 to 65% survival was obtained when NaCl or Naylor-Smith stabilizer was added to the cell suspensions before lyophilization. However, the stabilizers failed to increase significantly the levels of survival compared with water suspension when cells were lyophilized at pressures less than 10-5 torr. The high survival rates obtained by the high-vacuum technique may be attributed to the reduction of traces of molecular oxygen which has been reported to be destructive of the dried bacteria. Survival of unstabilized dried S. marcescens after 1-day storage increased markedly with decreasing sealing pressure. Under the highest vacuum attained, survival of the dried bacteria was not impaired by storage for up to 1 month at Dry Ice temperatures; at higher temperatures, viability losses occurred. Exposure of the dried unstabilized bacteria to dry air resulted in rapid viability loss. The inactivation could be stopped almost immediately by evacuation to pressures of less than 10-5 torr, but the evacuation failed to reverse the viability losses that occurred during exposure.
Accounting for economic growth : the case of Norway

The background of economic growth in Norway is reviewed. Models that derive the direct and indirect measures used in empirical estimation and aggregate estimates for Norway's economy are analyzed, and the results are compared to those of Japan. The adoption of an outward-looking policy has led to increases in both exports and imports in Norway entailing the reallocation of resources according to comparative advantage among industries as well as specialization within industries. It is noteworthy that per capita income grew more rapidly in the 1961 to 1969 subperiod, when the establishment of the European Free Trade Association gave a boost to exports, than between 1953 and 1961. The experiences of Norway and Japan during the period of import liberalization were similar. However, available data indicate that exports made a larger contribution to economic growth in Norway than in Japan. These differences may be due to factors such as the size of the domestic market, rates of imports protection, and Norway's free trade arrangement in manufactured goods within the free trade zone.
A new caged structure spin-on-silica for multilevel interconnect application

A unique, carbon-free silica material, based on a new concept of converting caged (HSiO/sub 3/2/)/sub n/ structures by eliminating the hydrogens and cross-linking the caged structures with oxygen, was characterized for ILD (interlayer dielectric) applications. The films show excellent uniformity as well as good planarity. At temperatures below 600 degrees C, no volume shrinkage is observed. However, above this temperature, volume losses of as much as 30% can be observed. FTIR (Fourier transform infrared) spectroscopy data and film stress measurements (used to determining film stability) show that a stable crack-free oxide (SiO/sub 2/) can be obtained with a high-temperature oven bake or with an optimized process combining low-temperature oven baking and exposure to oxygen plasma. These early results show that this spin-on-silica precursor is suitable for nonetchback processes such as those that involve oxide deposition between polysilicon and the first level of metal. With processing improvements at lower temperatures, the precursor also shows promise for intermetal oxide applications. >
Sustained Delayed Gastric Emptying During Repeated Restraint Stress in Oxytocin Knockout Mice

We have recently shown that impaired gastric motility observed in acute restraint stress was restored following repeated restraint stress in mice. Repeated restraint stress up-regulates oxytocin mRNA expression and down-regulates corticotrophin-releasing factor (CRF) mRNA expression at the hypothalamus. Oxytocin knockout mice (OXT-KO) have been widely used to study the central oxytocin signalling pathways in response to various stressors. We studied the effects of acute and repeated restraint stress on solid gastric emptying and hypothalamic CRF mRNA expression in wild-type (WT) and OXT-KO mice. Heterozygous (HZ) parents (B6; 129S-Oxt(tm1Wsy)/J mice) were bred in our animal facility. Male OXT-KO, WT and HZ littermates were used for the study. Solid gastric emptying was measured following acute restraint stress (for 90 min) or repeated restraint stress (for five consecutive days). Expression of CRF mRNA in the paraventricular nucleus (PVN) was measured by real-time reverse transcriptase-polymerase chain reaction. There were no significant differences of gastric emptying in WT (68.4 ± 4.1%, n = 6), HZ (71.8 ± 3.1%, n = 6) and OXT-KO (70.6 ± 3.1%, n = 6) mice in nonstressed conditions. Acute stress significantly delayed gastric emptying in OXT-KO mice (33.10 ± 2.5%, n = 6) WT (39.1 ± 1.1%, n = 6) and HZ mice (35.8 ± 1.2%, n = 6). Following repeated restraint stress loading, gastric emptying was significantly restored in WT (68.3 ± 4.5%, n = 6) and HZ mice (63.1 ± 2.6%, n = 6). By contrast, gastric emptying was still delayed in OXT-KO mice (34.7 ± 1.3%, n = 6) following repeated restraint stress. The increase in CRF mRNA expression at the PVN was much pronounced in OXT-KO mice compared to WT or HZ mice following repeated restraint stress. These findings suggest that central oxytocin plays a pivotal role in mediating the adaptation mechanism following repeated restraint stress in mice.
Abdominal Surgical Incision Induces Remote Preconditioning of Trauma (RPCT) via Activation of Bradykinin Receptors (BK2R) and the Cytochrome P450 Epoxygenase Pathway in Canine Hearts

Recently, a novel observation was made in which nonischemic trauma at a site remote from the heart produced by a transverse abdominal incision resulted in a marked reduction of infarct size (IS) in the mouse heart via activation of sensory nerve fibers in the skin and subsequent activation of bradykinin 2 receptors (BK2R). This phenomenon was termed remote preconditioning of trauma (RPCT). Since RPCT may have potential clinical implications we attempted to confirm these findings in a large animal model, the dog. The epoxyeicosatrienoic acids (EETs) have also recently been shown to be antinociceptive and have been shown to mimic ischemic preconditioning (IPC) and postconditioning (POC) in dogs, therefore, we tested the role of the EETs in RPCT. Anesthetized adult mongrel dogs of either sex were subjected to 60 min of left anterior descending (LAD) coronary artery occlusion followed by 3 h of reperfusion. In all groups except the controls (no slit), a transverse slit (9 cm) was applied to the abdominal wall of the dog being careful to only slit the skin. Subsequently, 15 min after the slit the heart was subjected to the ischemia/reperfusion protocol. In the control dogs, the IS as a percent of the area at risk (AAR) was 22.5 ± 2.4%, whereas in the dogs subjected to the slit alone the IS/AAR was reduced to 9.2 ± 1.2% (*P<0.01). The BR2R blocker, HOE 140 (50 ug/kg, iv) given 10 min prior to the slit, completely abolished the protective effects of RCPT as did pretreatment with 14,15-EEZE, a putative EET receptor blocker or pretreatment with the selective EET synthesis inhibitor, MSPPOH. These results suggest that BK and the EETs share cardioprotective properties in a large animal model of RPCT.
Chemotherapy of acute lymphoblastic leukemia in children

Between 1969-1973, 75 consecutive children under the age of 15 years with acute lymphoblastic leukemia were treated with a multiple-drug regimen (L-2). Prophylaxis for meningeal leukemia was limited to the repeated intrathecal injections of methotrexate. Seventy-four patients achieved remission; the duration of remissions could be evaluated only for 70. Relapse terminated complete remission within 1-54 months in 21 children. Four of these relapses were confined to the central nervous system. Forty-nine patients continue in complete remission from 23 to 63 months. Chemotherapy has been discontinued in 29 children, and 25 of these remain without evidence of recurrence for 2-27 months posttreatment.
Magnesium pemoline and Ehrlich tumor: tumor animal versus tumor cell survivals.

Es wird der Uberlebensprozentsatz von mit Magnesiumpemolin behandelten Tumorzellen und Tumormausen nach und ohne Rontgenbestrahlung verglichen: Die Substanz erhoht die Uberlebensrate der Tiere und verandert das Wachstumsbild der Tumorzellen. Magnesiumpemolin wahrend der Bestrahlung in niedriger Dosis oder ohne Bestrahlung in hoher Dosis erzielt beste Werte.
Fast Distributed Almost Stable Matchings

In their seminal work on the Stable Marriage Problem, Gale and Shapley describe an algorithm which finds a stable matching in O(n2) communication rounds. Their algorithm has a natural interpretation as a distributed algorithm where each player is represented by a single processor. In this distributed model, Floreen, Kaski, Polishchuk, and Suomela recently showed that for bounded preference lists, terminating the Gale-Shapley algorithm after a constant number of rounds results in an almost stable matching. In this paper, we describe a new deterministic distributed algorithm which finds an almost stable matching in O(log5 n) communication rounds for arbitrary preferences. We also present a faster randomized variant which requires O(log2 n) rounds. This run-time can be improved to O(1) rounds for "almost regular" (and in particular complete) preferences. To our knowledge, these are the first sub-polynomial round distributed algorithms for any variant of the stable marriage problem with unbounded preferences.
Kondo Resonances and Anomalous Gate Dependence in the Electrical Conductivity of Single-Molecule Transistors

We report Kondo resonances in the conduction of single-molecule transistors based on transition metal coordination complexes. We find Kondo temperatures in excess of 50 K, comparable to those in purely metallic systems. The observed gate dependence of the Kondo temperature is inconsistent with observations in semiconductor quantum dots and a simple single-dot-level model. We discuss possible explanations of this effect, in light of electronic structure calculations.
Inhibition of the ERK/MAP kinase pathway attenuates heme oxygenase-1 expression and heme-mediated neuronal injury

Hemin is an oxidant that accumulates in intracranial hematomas. Its neurotoxicity is increased by its breakdown, which is catalyzed by the heme oxygenase (HO) enzymes. In this study we tested the hypothesis that inhibiting signaling events mediating HO-1 induction would protect cultured cortical neurons from hemin. A fivefold increase in HO-1 expression was observed in mixed neuron-astrocyte cultures 4h after hemin exposure. This was markedly reduced by the ERK pathway inhibitor U0126. The JNK inhibitor SP600125 had a weak but statistically significant effect, while the p38 inhibitor SB239063 was ineffective. Hemin neurotoxicity, as assessed by LDH release, propidium iodide staining, and malondialdehyde assay, was also prevented by U0126 but not by SB239063; SP600125 had little or no effect. Consistent with reduced iron release, ferritin expression was also attenuated by U0126, while cell hemin accumulation was increased. These results suggest that targeting the ERK pathway may prevent HO-1 induction in response to hemin, and reduce neuronal injury.
The MammoSite ® breast brachytherapy device: targeted delivery of breast brachytherapy

The MammoSite breast brachytherapy device was designed to overcome the logistic difficulties presented by external beam radiation therapy and the technical difficulties of multicatheter-based interstitial brachytherapy. The device consists of a silicone balloon connected to a catheter which contains an inflation channel and a port for passage of a high-dose-rate brachytherapy source. The American Brachytherapy Society and American Society of Breast Surgeons have published partial breast irradiation patient selection guidelines. Initial reports have shown a favorable cosmetic outcome in the majority of patients. The MammoSite applicator has also been associated with minimal side effects. The NSABP B-39/RTOG 0413 trial will randomize patients to either whole breast irradiation or partial-breast irradiation consisting of interstitial brachytherapy, MammoSite brachytherapy, or 3D conformal radiation. This national randomized trial has the potential to provide a definitive answer regarding the benefits of partial-breast irradiation, and therefore lead to more women undergoing breast conserving therapy.
MULTIPLICATIVELY CLOSED SETS OF IDEALS AND RESIDUAL DIVISION

Let R be a ring (commutative with identity), let Γ be a multiplicatively closed set of finitely generated nonzero ideals of R, for an ideal I of R let I Γ = ∪ {I : G; G ∈ Γ}, and for an R-algebra A such that GA ≠ (0) for all G ∈ Γ let A Γ = ∪ {A : T GA; G ∈ Γ}, where T is the total quotient ring of A. Then I Γ is an ideal in R, I → I Γ is a semi-prime operation (on the set I of ideals I of R) that satisfies a cancellation law, and it is a prime operation on I if and only if R = R Γ. Also, A Γ is an R-algebra and A → A Γ is a closure operation on any set A = {A; A is an R-algebra, R ⊆ A, and if C is a ring between R and A, then regular elements in C remain regular in A}. Finally, several results are proved concerning relations between the ideals I Γ and (IA)ΓA and between the R-algebras R Γ and A Γ. *Ahmad died of a heart attack on January 28, 2000. He was the gentlest, kindest, most humble of men. -LJR
Rearrangement of O-arenesulfonyl phenylhydroxylamines

Abstract When treated with arenesulfonyl chlorides, phenylhydroxylamines rearrange to o -arene-sulfonyloxyaniline derivatives. The rearrangement of N-benzoyl-phenylhydroxylamine, under the influence of p -nitrobenzenesulfonyl chloride, was studied in detail. The ortho : para ratio is greater than 50. The oxygen introduced into the aniline ring comes exclusively from the sulfonyl group on the sulfonyl chloride, as shown by O 18 labeling. This demands a concerted. cyclic mechanism for the rearrangement of the intermediate N-benzoyl-N-( p -nitrobenzenesulfonyloxy) aniline.
Pesticide side-effects on arthropod natural enemies: A database summary

Abstract The literature on pesticide side-effects on arthropod natural enemies has greatly expanded since the 1950s. A database (SELCTV) of this literature has been developed for characterization, analysis and use in decision-making for pest control and environmental impact assessment. Currently, the database holds some 12 600 records containing pesticide side-effects information for over 600 species of natural enemies and 400 agricultural chemicals. Each database record is composed of 40 fields. A record includes information on the natural enemy species tested, the chemical pesticide and its attributes, the conditions of pesticide exposure and associated natural enemy response, and the literature source of the information. In addition to characterizing the literature, all pesticide/natural enemy response data were translated to a scale ranging from 1 (0% effect) to 5 (90–100% effect). Lethal and sublethal effects are presented for many species, pesticide and test method data groupings. Some general trends from the database are that predators are less susceptible and more variable in response to pesticides than parasitoids. Some species very tolerant to pesticides are the spider, Lycosa pseudoannulata, the coccinellid, Cryptolaemus montrouzieri, and the chrysopid, Chrysopa carnea. Insecticides are the most toxic pesticide class to predators and parasitoids, followed by herbicides, acaricides and fungicides, respectively. Among insecticide classes, a trend of increasing toxicity to natural enemies is present from the early inorganics to the synthetic pyrethroids. More recent microbials and insect growth regulators seem less toxic and more selective. Differences in the susceptibility trends among pests, predators and parasitoids are discussed.
High precision iron isotope measurements of meteoritic material by cold plasma ICP-MS

The first cold plasma ICP-MS (inductively coupled plasma mass spectrometer) Fe isotope study is described. Application of this technique to the analyses of Fe isotopes in a number of meteorites is also reported. The measurement technique relies on reduced temperature operation of the ICP source to eliminate pervasive molecular interferences from Ar complexes associated with conventional ICP-MS. Instrumental mass bias corrections are performed by sample-standard bracketing and using Cu as an external mass bias drift monitor. Repeated measurements of a terrestrial basalt reference sample indicate an external reproducibility of ± 0.06 ‰ for δ56Fe and ± 0.25 ‰ for δ58Fe (1 σ). The measured iron isotopic compositions of various bulk meteorites, including irons, chondrites and pallasites are identical, within error, to the composition of our terrestrial basalt reference sample suggesting that iron mass fractionation during planet formation and differentiation was non-existent. Iron isotope compositions measured for eight chondrules from the unequilibrated ordinary chondrite Tieschitz range from −0.5 ‰ < δ56Fechondrules < 0.0 ‰ relative to the terrestrial/meteorite average. Mechanisms for fractionating iron in these chondrules are discussed.
Symmetry breaking in three-generation Calabi-Yau manifolds

The spontaneous breaking of [SU(3)${]}^{3}$ symmetry to SU(3)\ifmmode\times\else\texttimes\fi{}SU(2)\ifmmode\times\else\texttimes\fi{}U(1) due to nonrenormalizable interactions in the three-generation Calabi-Yau superstring model is considered. It is seen that these models lead naturally to intermediate scales ${M}_{I}$\ensuremath{\sim}${10}^{15}$ GeV with simultaneous formation of N and ${\ensuremath{\nu}}^{c}$ vacuum expectation values (VEV's). The lowest-lying extrema automatically preserve matter parity and hence protect the model against too rapid proton decay. Models with matter parity also protect against electroweak Higgs VEV's from forming at ${M}_{I}$. The intermediate mass scale produces some particles with mass O(${M}_{I}$). It also implies the existence of others with mass \ensuremath{\sim}1 TeV, which are possibly accessible to low-energy experiments.
Monte Carlo study of weighted percolation clusters relevant to the Potts models

The two-dimensional Potts models were simulated with the use of a Monte Carlo method. This study is unique in that we simulated the weighted percolation clusters first described by Kasteleyn and Fortuin in 1969. We describe an auxiliary data structure which enables us to determine the connectedness of large clusters very efficiently. Our simulation of the percolation problem was found not to be affected by a critical slowing down. Critical exponents were found by studying the size and shape of large clusters. Our results agree with previous studies done on integer values of $q$, and with the conjecture of den Nijs.
Cholesterol content of human liver after feeding of corn oil and hydrogenated coconut oil.

SummaryThree ounces of corn oil daily were added to the diets of 6 men for a period of one month. Three ounces of hydrogenated coconut oil daily were added to the diets of a similar group of controls. Serum cholesterol concentration fell an average of 9% in the men fed corn oil, but did not change significantly in the controls. Liver cholesterol concentration, as measured by liver biopsy, fell an average of 25% in the men fed corn oil. No consistent effect was observed in the controls. It is concluded that the fall in serum cholesterol produced by corn oil feeding in man is probably not due to a shift of cholesterol from the blood to the liver.
Use of heteropolymeric monoclonal antibodies to attach antigens to the C3b receptor of human erythrocytes: a potential therapeutic treatment.

Abstract We have prepared bispecific, cross-linked monoclonal antibodies (heteropolymers) with specificity for both targeted antigens and the human erythrocyte (RBC) complement receptor. These heteropolymers facilitate binding of target antigens (human IgG and dinitrophenylated bovine gamma globulin) to human RBCs under conditions that either allow or preclude complement activation. Quantitative analyses of this binding agree well with the number of complement receptors per RBC. In vitro "whole-blood" model experiments indicate heteropolymer-facilitated binding of antigens to RBCs is rapid and stable at 37 degrees C. It may be possible to extend these prototype experiments to the in vivo situation and use heteropolymer-attached RBCs for the safe and rapid binding, neutralization, and removal from the circulation of pathogenic antigens associated with infectious disease.
Optical characterization of the InFocus TVT-6000 liquid crystal television (LCTV) using custom drive electronics

Liquid crystal televisions are popular low-cost spatial light modulators. One LCTV of interest is found in the InFocus TVT-6000 television projector. A wavefront splitting interferometer has been constructed and analyzed for measuring the complex characteristics of these modulators, including phase and amplitude coupling. The results of this evaluation using the TVT-6000 projector drive electronics have been presented in a previous work. This work will present results of the complex characterizations of these modulators using custom drive electronics.
Pressure-Sensitive Paint Measurements on the NASA Common Research Model in the NASA 11-ft Transonic Wind Tunnel

The luminescence lifetime technique was used to make pressure-sensitive paint (PSP) measurements on a 2.7% Common Research Model in the NASA Ames 11ft Transonic Wind Tunnel. PSP data were obtained on the upper and lower surfaces of the wing and horizontal tail, as well as one side of the fuselage. Data were taken for several model attitudes of interest at Mach numbers between 0.70 and 0.87. Image data were mapped onto a three-dimensional surface grid suitable both for comparison with CFD and for integration of pressures to determine loads. Luminescence lifetime measurements were made using strobed LED (light-emitting diode) lamps to illuminate the PSP and fast- framing interline transfer cameras to acquire the PSP emission.
Changes in respiratory burst activity during human monocyte differentiation in suspension culture.

Monocytes undergo a process of differentiation following their accumulation into extravascular spaces. This process has been examined previously by culturing monocytes and identifying changes in cell morphology, metabolism, and function over time. The present study was designed to characterize mononuclear phagocyte respiratory burst activity as related to differentiation by measuring chemiluminescence and Superoxide anion generation in cultured human monocytes. Monocytes maintained in Teflon vials for up to 12 days increased in size, were positive for nonspecific esterase, and retained the ability to ingest latex particles. During culture, however, cells progressively lost their peroxidase-positive granules. When monocytes were cultured for one or five days, they elicited less than 50% of the luminol-enhanced chemiluminescence produced by fresh monocytes following PMA stimulation. By day 7, less than 20% of day 0 PMA-elicited chemiluminescence was observed. A comparable loss of serum-opsonized zymosan-induced chemiluminescence occurred during monocyte culture. Since it is recognized that luminol-enhanced chemiluminescence is, in large part, dependent upon myeloperoxidase and since differentiated mononuclear phagocytes are only minimally peroxidase-positive, cultured monocyte respiratory burst activity was also assessed by directly quantifying Superoxide anion generation. When monocytes were cultured for three or five days, they elicited 38% more Superoxide anion than did fresh monocytes following PMA stimulation. At day 7, PMA-induced Superoxide anion release was comparable to day 0 levels. These data indicate that monocytes allowed to differentiate under nonadherent conditions maintain the ability to undergo a respiratory burst response as measured by Superoxide anion release, but they concomitantly lose peroxidase-dependent luminol-enhanced chemiluminescence. In this regard, monocytes cultured in suspension metabolically resemble macrophages that have undergone differentiation within sites of inflammation.
Brainstem projections to the phrenic nucleus: an anterograde and retrograde HRP study in the rabbit.

Brainstem projections to the phrenic nucleus were studied in rabbits using horseradish peroxidase conjugated with wheat germ agglutinin (WGA-HRP) as a retrograde and anterograde neuronal tracer. Injections of 1% WGA-HRP were centered in the phrenic nucleus in the C4-C5 ventral horn in 4 rabbits to identify pontomedullary nuclear groups that contain neurons projecting to the midcervical spinal cord. Regions of the rabbit brainstem that are homologous to the ventral respiratory group (VRG), dorsal respiratory group (DRG), Botzinger Complex (BotC) and Kolliker-Fuse nucleus in the cat and rat were shown to provide the major pontomedullary projections to the phrenic nucleus. Injections of WGA-HRP into physiologically identified locations within DRG, VRG and BotC anterogradely labelled bulbospinal axons of these groups. These injections produced presumptive terminal labelling in the C4-C5 ventral horn in the region containing the phrenic cell column and the transverse phrenic motoneuron dendrite bundles as defined by WGA-HRP labelling of phrenic motoneurons. These results indicate: 1) The presumptive excitatory (DRG, VRG) and inhibitory (BotC) bulbospinal control of phrenic motoneurons arise from the same medullary respiratory groups in the rabbit as in the cat and rat. 2) The bulbospinal control of phrenic motoneurons is primarily via direct projections to the phrenic motor nucleus, and not through segmental propriospinal interneurons. 3) As in the rat, the bulbospinal contribution of the DRG is less pronounced in the rabbit than in the cat. 4) The rabbit and rat have a slight ipsilateral predominance in their bulbospinal projections to phrenic nucleus; whereas these projections have a contralateral predominance in the cat.
Pattern-specific loss of aquaporin-4 immunoreactivity distinguishes neuromyelitis optica from multiple sclerosis

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease that typically affects optic nerves and spinal cord. Its pathogenic relationship to multiple sclerosis (MS) is uncertain. Unlike MS, NMO lesions are characterized by deposits of IgG and IgM co-localizing with products of complement activation in a vasculocentric pattern around thickened hyalinized blood vessels, suggesting a pathogenic role for humoral immunity targeting an antigen in the perivascular space. A recently identified specific serum autoantibody biomarker, NMO-IgG, targets aquaporin-4 (AQP4), the most abundant water channel protein in the CNS, which is highly concentrated in astrocytic foot processes. We analysed and compared patterns of AQP4 immunoreactivity in CNS tissues of nine patients with NMO, 13 with MS, nine with infarcts and five normal controls. In normal brain, optic nerve and spinal cord, the distribution of AQP4 expression resembles the vasculocentric pattern of immune complex deposition observed in NMO lesions. In contrast to MS lesions, which exhibit stage-dependent loss of AQP4, all NMO lesions demonstrate a striking loss of AQP4 regardless of the stage of demyelinating activity, extent of tissue necrosis, or site of CNS involvement. We identified a novel NMO lesion in the spinal cord and medullary tegmentum extending into the area postrema, characterized by AQP4 loss in foci that were inflammatory and oedematous, but neither demyelinated nor necrotic. Foci of AQP4 loss coincided with sites of intense vasculocentric immune complex deposition. These findings strongly support a role for a complement activating AQP4-specific autoantibody as the initiator of the NMO lesion, and further distinguish NMO from MS.
Transcriptional regulation of the neuronal L-type calcium channel α1D subunit gene

1. The transcriptional regulation of the rat brain L-type calcium channel α1D subunit (RBα1D) gene was investigated using NG108-15 neuroblastoma-glioma cells. 2. Differentiation of NG108-15 cells in the presence of prostaglandin E1 or retinoic acid resulted in the appearance of mRNA encoding the RBα1D subunit detected using Northern blot analysis. 3. A rat genomic DNA library was screened, and a 15.2-kb clone was isolated and partially sequenced which included part of the 5′ upstream sequence through the initial part of intron 2 of the RBα1D gene. 4. Deletion analysis, using a CAT reporter gene and transfected NG108-15 cells, revealed that the 1.2-kb 5′-upstream sequence from the RBα1D gene contains cis-acting positive and negative regulatory elements. A deletion of the 3′ end of exon 1 also suggested the presence of regulatory elements in the first exon. 5. DNase footprinting of exon 1 of the RBα1D gene revealed two regions protected from digestion by specific protein binding, and the second region included an (ATG)7 trinucleotide repeat sequence. Electrophoretic mobility shift assays confirmed nuclear protein(s) binding to the (ATG)7 sequence. 6. The (ATG)7 sequence functions as a enhancer when linked to a thymidine kinase promoter and a CAT reporter gene. 7. These results provide the initial description of the transcriptional regulation of the RBα1D gene and identify a novel enhancer that consists of an (ATG)7 trinucleotide repeat sequence.
Friction in metal machining—Mechanical aspects

Abstract A review is presented concerning the mechanical aspects of friction at the land and rake faces of a cutting tool when machining under orthogonal conditions. Methods are described for determining the mean frictional and normal forces on these faces and calculating the mean coefficients of friction. Considerable confusion exists concerning the nature of the frictional conditions in the region of the tool land to the point where definitive conclusions cannot be drawn. However, it is suggested that sliding and subsurface plastic deformation may occur simultaneously. When machining under dry, unlubricated conditions regions of sticking friction where the frictional stress is constant and sliding friction where the coefficient of friction is constant can exist simultaneously on the tool rake face. Theories which predict a linear relationship of the form ( φ ) = A − B ( β − α ) between the angle parameters used to describe the geometry of the cutting process cannot be used to interpret much of the available experimental data. The apparent linear relationships observed in some previous experimental work are thought to be due partly to the method of presentation of the results. It is suggested that a more significant combination of the angle parameters is the difference between the shear angle φ and rake angle a, that is (φ−α). Two parameters which can be used to describe the frictional conditions at the tool rake face are the mean frictional stress and mean normal stress which can vary independently of each other. It is concluded that the mean angle of friction β is insufficient in itself to describe the frictional conditions on the tool rake face. The effects of changes in cutting conditions on the mean coefficient of friction at the tool rake face are examined and the results interpreted in terms of the associated changes in the mean normal and mean frictional stresses in that region. The lubricating action of cutting fluids is discussed briefly.
A first-order scattering solution for modelling elastic wave codas — I. The acoustic case

Summary A corrected, first-order solution for modelling acoustic wave scattering in layered halfspaces containing random inhomogeneities is derived. Energy lost to higher order scattering and intrinsic attenuation is included in the correction, which is constructed so that energy is conserved to first order. The complex propagation effects of the layering are overcome by representing the motion as a sum of normal modes. This approach renders the kinematic description of the scattering two dimensional, with the wave vectors of incident and scattered modes lying parallel to the layering. At each level in the halfspace, the inhomogeneities are resolved into two-dimensional Fourier spectra also parallel to the layering. The root mean square (rms) motion of a scattered mode depends on the correlation between spectra at different levels and the group velocity of the mode. To simplify the solution, it is assumed that the inhomogeneity spectra are piecewise constant and that the energy of a normal model propagates only at its group velocity. The final step of the theory establishes a criterion for the source—receiver separations over which the results are accurate. Numerical calculations have been carried out for a single layer of inhomogeneities over a halfspace. The spectra of the inhomogeneities were assumed band limited, and several different spectra were examined. The results suggest the existence of a diagonal selection rule whereby a wavelet of mode order n scatters mostly to wavelets of the same order. Moreover, a resonant frequency of scattering occurs, causing the rms signal to appear monochromatic. The frequency of the resonance is controlled by the inhomogeneity spectra band limits. With the aid of the diagonal selection rule, the simplified solution allows for both rapid computation of synthetic signals and inversion of data for scattering cross-section. Existing data suggest the theory may be applied to obtain approximate models of local earthquake codas. The synthetic signals of the single layer cases, for example, have codas similar to published observations. To illustrate the inversion of data with the theory, a preliminary scattering cross-section for the lunar crust is presented.
Effects of the El Chichón volcanic cloud on solar radiation received at Fairbanks, Alaska

Abstract Detailed insulation measurements have been carried out in Fairbanks for the last four years. Beginning on 15 November 1982, these measurements showed substantial changes, believed to be due to the dust cloud of El Chichon. The volcano, situated in Mexico, erupted most intensely on 4 April 1982, putting a large amount of material into the atmosphere. The long travelling time to the North is in line with results found by Rao and Bradley (1983). Compared to clear-day data for previous years, clear days for the time period 15 November 1982–31 May 1983 showed a decrease in the direct beam of24.8%, an increase in the ratio of diffuse to global radiation of 76%, and a decrease in the global radiation of about 5%. A decrease in the direct beam, a substantial increase in the diffuse radiation, and a small decrease in the global radiation are typical for increased turbidity of the atmosphere, but the volcanic cloud caused changes greater than those due to "normal" turbidity changes.
Fatigue fracture-surface roughness and the K-opening level

Abstract An investigation utilizing the aluminum alloy 8009 has been carried out in the near-threshold range in an effort to determine the factors involved in the rise in K op with ΔK in this alloy. It is noted that whereas a number of structural aluminum alloys exhibit a rise in K op with ΔK , not all do, nor do the steels which we have tested in the near-threshold range. For the 8009 alloy it is concluded crack closure is roughness-induced, and that the rise is in K op with ΔK is wear-related, with more wear occuring the lower the ΔK value because more closure cycles are spent at a given location of the crack front the lower the crack growth rate.
Bioreactor operation for the production of exotoxin A by Pseudomonas aeruginosa.

Discussed here are experiments aimed at developing an optimal production strategy for an exocellular protein under regulatory control, i.e. exotoxin A (ETA), which is produced by Pseudomonas aeruginosa. Using established techniques from molecular biology, information on ETA mRNA levels could be obtained and used to improve the production strategy for this exotoxin. The implications for other gene products under regulatory control also are presented