cssi/SciSciGPT-SciSciNet huggingface dataset:
Foot Force Based Reactive Stability of Multi-Legged Robots to External Perturbations

Many environments and scenarios contain rough and irregular terrain and are inaccessible or hazardous for humans. Robotic automation is preferred in lieu of placing humans at risk. Legged locomotion is more advantageous in traversing complex terrain but requires constant monitoring and correction to maintain system stability. This paper presents a multi-legged reactive stability control method for maintaining system stability under external perturbations. Assuming tumbling instability and sufficient friction to prevent slippage, the reactive stability control method is based solely on the measured foot forces normal to the contact surface, reducing computation time and sensor information. Under external perturbations, the reactive stability control method opts to either displace the CG or the foot contacts of the robot based on the measured foot force distribution. Details describing the reactive stability control method are discussed including algorithms and an implementation example. An experimental demonstration of the reactive stability control method is presented. The experiment was conducted on a hexapod robot platform retrofitted with a tiny computer and force sensitive resistors to measure the foot forces. The experimental results show that the presented reactive stability control strategy prevents the robot from tipping over under external perturbation.
Design and Implementation of Scalable Admission Control

While the IntServ solution to Internet QoS can achieve a strong service model that guarantees flow throughputs and loss rates, it places excessive burdens on high-speed core routers to signal, schedule, and manage state for individual flows. Alternatively, the DiffServ solution achieves scalability via aggregate control, yet cannot ensure a particular QoS to individual flows. To simultaneously achieve scalability and a strong service model, we have designed and implemented a novel architecture and admission control algorithm termed Egress Admission Control. In our approach, the available service on a network path is passively monitored, and admission control is performed only at egress nodes, incorporating the effects of cross traffic with implicit measurements rather than with explicit signaling. In this paper, we describe our implementation of the scheme on a network of prototype routers enhanced with ingress-egress path monitoring and edge admission control. We report the results of testbed experiments and demonstrate the feasibility of an edge-based architecture for providing IntServ-like services in a scalable way.
Putrescine and the regulation of S-adenosyl-L-methionine decarboxylase in cultured mouse mammary gland.

The activity of S-adenosyl-l-methionine decarboxylase S-adenosyl-l-methionine carboxy-lyase, EC 4.1.1.50) purified from mouse mammary gland can be stimulated by physiological concentrations of putrescine (Ka = 5 · 10-7M). In contrast, the elevation of the intracellular concentrations of putrescine in cultured mouse mammary tissue by exogenous addition of putrescine or by cultivation of the tissue in hypotonic medium results in the decrease in both the activity and the amount of the enzyme in tissue. Conversely, the addition of 1 mM α-methyl ornithine, an inhibitor of ornithine decarboxylase, causes augmentation of the activity and the amount of S-adenosyl-l-methionine decarboxylase, despite its inhibitory action on insulin-stimulated increase in the concentration of putrescine. These data suggest that putrescine can act as a ‘negative’ regulator of the enzyme in this system.
Effects of salinity and light on organic carbon and nitrogen uptake in a hypersaline microbial mat

Utilization of dissolved organic matter (DOM) is thought to be the purview of heterotrophic microorganisms, but photoautotrophs can take up dissolved organic nitrogen (DON) and dissolved organic carbon (DOC). This study investigated DOC and DON uptake in a laminated cyanobacterial mat community from hypersaline Salt Pond (San Salvador, Bahamas). The total community uptake of 3H-labeled substrates was measured in the light and in the dark and under conditions of high and low salinity. Salinity was the primary control of DOM uptake, with increased uptake occurring under low-salinity, ‘freshened’ conditions. DOC uptake was also enhanced in the light as compared with the dark and in samples incubated with the photosystem II inhibitor 3(3,4-dichlorophenyl)-1, 1-dimethylurea, suggesting a positive association between photosynthetic activity and DOC uptake. Microautoradiography revealed that some DOM uptake was attributed to cyanobacteria. Cyanobacteria DOM uptake was negatively correlated with that of smaller filamentous microorganisms, and DOM uptake by individual coccoid cells was negatively correlated with uptake by colonial coccoids. These patterns of activity suggest that Salt Pond microorganisms are engaged in resource partitioning, and DOM utilization may provide a metabolic boost to both heterotrophs and photoautrophs during periods of lowered salinity.
USE OF A FLUORESCEIN-LABELED SONICALLY DISRUPTED BACTERIAL ANTIGEN TO DEMONSTRATE ANTIBODY-PRODUCING CELLS

Abstract Eveland, Warren C. (University of Michigan, Ann Arbor). Use of a fluorescein-labeled sonically disrupted bacterial antigen to demonstrate antibody-producing cells. J. Bacteriol. 88:1476–1481. 1964.—Cells obtained by primary tissue culture of the spleens of chickens immunized with sonically disrupted Escherichia coli O111 organisms were stained with a fluorescein-labeled homologous antigen by use of direct immunofluorescent methods. Brilliant staining of the cytoplasm in cells from immunized birds appeared to be diffuse in certain cells and rather globular in others. In contrast, cells from nonimmunized birds showed no staining at all. The cells involved in the specific reaction appeared to be those of the lymphocyte-monocyte-plasma cell types, as shown when stained by the May-Grunwald-Giemsa method. Preparations stained by the methyl green-pyronin technique revealed an increase in the pyrinophilic cells in the preparations from the immunized birds, thus demonstrating increased amounts of ribonucleic acid in these cells, which in turn is consistent with the presence of antibody globulin. Specificity of the reaction was confirmed also by (i) staining antibody-coated E. coli O111 organisms with the conjugate, (ii) precipitin reaction with specific antibody, and (iii) specific agglutination with circulating antibody from the immunized birds.
Enhancement of ethanol-induced sleep by whole oil of nutmeg

In young chickens, the whole oil of nutmeg (200 mg/kg) increased the duration of sleep induced by ethanol (1--4 g/kg), particularly deep sleep. Iproniazid (50-400 mg/kg), a monoamine oxidase inhibitor, did not mimic this effect.
A measurement of the welfare loss in the terminal equiphint makket

This arlicie allempts to estimate the wellare loss in the terminal equipment market due to the existence of monopoly power and entry barriers. The welfare loss consists of two parts, one due to price above marginal cost, and the second due to product voids. By using certain upper and lower bound measurements, we obtain an estimate of the minimum welfare loss of $35 million and a maximum welfare loss of $639 million for a one year time period.
Direct measurement of quantum phases in graphene via photoemission spectroscopy

Quantum phases provide us with important information for understanding the fundamental properties of a system. However, the observation of quantum phases, such as Berry's phase and the sign of the matrix element of the Hamiltonian between two nonequivalent localized orbitals in a tight-binding formalism, has been challenged by the presence of other factors, e.g. , dynamic phases and spin or valley degeneracy, and the absence of methodology. Here, we report a way to directly access these quantum phases, through polarization-dependent angle-resolved photoemission spectroscopy (ARPES), using graphene as a prototypical two-dimensional material. We show that the momentum- and polarization-dependent spectral intensity provides direct measurements of (i) the phase of the band wavefunction and (ii) the sign of matrix elements for nonequivalent orbitals. Upon rotating light polarization by $\ensuremath{\pi}/2$, we found that graphene with a Berry's phase of $n\ensuremath{\pi}$ ($n=1$ for single- and $n=2$ for double-layer graphene for Bloch wavefunction in the commonly used form) exhibits the rotation of ARPES intensity by $\ensuremath{\pi}/n$, and that ARPES signals reveal the signs of the matrix elements in both single- and double-layer graphene. The method provides a technique to directly extract fundamental quantum electronic information on a variety of materials.
Enzymic synthesis and properties of polynucleotide from adenosine diphosphate.

THE well-known viscous nature of solutions of lysed cells of M. lysodeiklicus, attributed in part to nucleic acids, led to the search for an active nucleotide polymerase in this organism. Preliminary studies with 14C-labelled adenosine diphosphate (ADP) (the initial paper chromatographic studies were done in collaboration with Dr. Peter Olmsted) and the technique described by Grunberg-Manago and Ochoa1 revealed the presence of such an enzyme. The present communication deals with the enzymic synthesis and properties of the polymer (AMP)n.
Failure of Oral Versus Parenteral Corticosteroids in a Case of Acute Inflammatory Polyradiculoneuropathy (GuiIlain‐Barré Syndrome)

Summary: Failure of oral versus parenteral corticosteroids in a case of acute inflammatory polyradiculoneuropathy (Guillain-Barre syndrome). R. A. Brumback, Aust. N.Z. J. Med., 1980. 10, pp. 224–226. A case of acute inflammatory polyradiculoneuropathy (IPN, Guillain-Barre syndrome) not responding to oral corticosteroids but showing marked improvement on parenteral corticosteroids is reported. Oral prednisone 60 mg/day was begun on hospital admission and increased after one week to 100 mg/day; however, the patient's respiratory function, demonstrated by forced vital capacity, continued to deteriorate. lmprovement was noted when the patient was switched to intravenous methyl-prednisolone 100 mglday. Further attempts to use oral corticosteroids (including oral methyl-prednisolone 96 mg/day) resulted in deterioration of the patient's function
Long-term valuation effects of stock splits

This study attempts to determine if stock splits affect the long-term stock performance of forms, and to explain cross-sectional variation in this performance proxy among firms. The consequences of both higher percentage transaction cost following a stock split and an investor overreaction hypothesis are expected to render negative effects on stock values. The consequences of any earnings and dividend signaling accompanying splits are expected to have a positive impact on stock values. The results of the analysis suggest that the cumulative abnormal returns (CARs) are positive and statistically significant through the eleventh month after a stock split. The CARs then decrease nearly monotonically through the thirty-sixth month after the split (CAR=−8.23%). This indicates that initially the signaling effects dominate, but later the consequences of investors' downward revisions of previous expectations and the increase in percentage transaction cost dominate. The cross-sectional results indicate that firms with higher earnings-growth rates exhibit higher CARs, and firms with higher share prices just before the split exhibit lower CRRs.
Systematic infrared ablations with the mark III FEL at 2.94 μm in the chicken cornea

Abstract Introduction. Previous studies with the free electron laser have only assessed the corneal tissue response in ex vivo models. This is the first free electron laser investigation that has examined the clinical and histologic response of the cornea in vivo . Methods. The Mark III free electron laser was tuned to 2.94 μm for a total of 212 separate in vivo 1 mm spot ablations at varied fluences (0.4–2.04 J/cm 2 ), repetition rates (1–15 Hz), and number of pulses (1–32). Also, 22 separate in vivo central scanning patterns were performed. Results. For the in vivo chicken cornea, the threshold of ablation is approximately 0.64 J/cm 2 at a repetition rate of 10 Hz. Clinical biomicroscopy and light microscopy revealed parameter-dependent collateral damage (10–40) μm) induced by laser energy. Wound healing following free electron laser ablation exhibits patterns similar to those seen in excimer laser anterior keratectomy, including increased epithelial thickness, new collagen deposition, increased numbers of keratocytes, and patterns congruent with attempted profiles of myopic ablation. Conclusions. With further study, continued parameter adjustment, and refined delivery schemes, the potential for marked improvement and possible application appears promising.
Nonlinear-optical energy regulation by nonlinear refraction and absorption in silicon

We demonstrate a new silicon picosecond nonlinear-optical energy regulator for 1-μm radiation. The device has a high transmission for low input energies and a low transmission for high input energies and clamps the output at a constant value. We attribute this optical Zener action to nonlinear refraction and absorption induced in the silicon by the intense picosecond pulses.
Modality Interactions of Speech and Signing in Simultaneous Communication.

This study addresses speech and signing interaction during simultaneous communication (SC). Productions of sentence stimuli by ASL-English bilinguals (CODAs) and signed English (SE) users who know no ASL (SIMCOMs) were compared in two conditions (speech-alone or signing-alone, speech and signing combined). Speech took longer combined than alone, whereas SE took longer alone than combined. The increased duration of speech-combined resulted from increased syllable duration, number of gaps, and gap duration. Rate of signing had a significant effect on speech duration. The decreased duration of signed sentences combined resulted from decreased sign duration, decreased gap duration, and increased sign omissions. Knowledge of ASL was reflected in qualitative differences between the two groups. Sign omissions were analyzed by grammatical category; these are discussed in terms of context-supported permissible deletions and the compensatory use of ASL nonmanual marking devices.
Education for the Health Communication Professional: A Collaborative Curricular Partnership

This article provides the context and rationale for a unique partnership of a communication college and medical school synergistically combining resources to create a master's degree program specifically in health communication. The architects of this revolutionary educational approach to health communication at Emerson College and Tufts University School of Medicine offer suggestions for administrators and professors interested in advancing health communication education. A slightly modified version of the actual proposal of a unique academic relationship to educate leaders in the field of health communication is discussed in relation to the target audience, curriculum, and career opportunities. Given the groundbreaking nature of the program, it is presented as an exemplar, with a copy of the proposal approved by each institution's Board of Trustees.
The Effects of Computer Use on the Acquisition of Multiplication Facts by a Student with Learning Disabilities

Two investigations of a single student having a specific mathematics disability were conducted in order to determine the effectiveness of software use alone, or in combination with teacher intervention, on the acquisition of multiplication facts. The types of software were drill-and-practice and tutorial based, with the drill program being used as the sole intervention in the first study and the tutorial program being used in conjunction with teacher intervention during the second study. The teacher intervention involved (1) determination of the student's present problem solution strategy, (2) the teaching of an alternative solution strategy called The Rule of Nines," and (3) the presentation and use of computer software with the student. Results indicated an initial increase in correct responding and a corresponding decrease in the amount of time to response for both drill-and-practice and tutorial software, but this effect proved to be transitory with both errors and times increasing when the student wa...
Economic impacts of quality awards: Does offering an award bring returns to the state?

The winners of the United States' Malcolm Baldrige National Quality Award have shown greater increases in the price of their stocks than the increase in the Dow Jones Industrial average. Other returns from quality awards have not been clearly established to date. In 2000, 42 states within the USA offered quality awards. Many of these awards have as one major objective improving the economic conditions of the state itself. But does offering a quality award bring economic returns to the state? Economic data collected include employment growth, business formations and per capita income. Award data include year of inception. number of levels of award offered and number of awards given each year since inception. Analysis of variance and regression analyses were performed using economic data as dependent variables and award data as independent variables to test the hypothesis that having an award improves the economy.
Morph-Based Local-Search Heuristics for Large-Scale Combinatorial Data Analysis

There are a variety of data analysis techniques in the social and behavioral sciences that require the solution of NP-complete optimization problems. Unfortunately, optimal solution methods are generally intractable for problems of practical size and thus there has been an emphasis on the development of heuristic procedures. Although local-search procedures, such as simulated annealing, have been tested on several combinatorial data analysis problems, they have frequently been criticized as computationally inefficient and therefore impractical for large problems. This paper presents a process called ‘morphing’ that can substantially increase the efficiency and effectiveness of local-search heuristics. The new procedure is compared to replications of a heuristic battery of local-operations across a set of large metric unidimensional scaling (seriation) problems. Generalizations of the morphing process to other problems in combinatorial data analysis are also discussed.
Cardiorespiratory fitness mediates the effects of aging on cerebral blood flow.

The brain’s vasculature is likely to be subjected to the same age-related physiological and anatomical changes affecting the rest of the cardiovascular system. Since aerobic fitness is known to alleviate both cognitive and volumetric losses in the brain, it is important to investigate some of the possible mechanisms underlying these beneficial changes. Here we investigated the role that estimated cardiorespiratory fitness (eCRF) plays in determining the relationship between aging and cerebral blood flow (CBF) in a group of older adults (ages 55-85). Using arterial spin labeling to quantify CBF, we found that blood flow in the gray matter was positively correlated with eCRF and negatively correlated with age. Subsequent analyses revealed that eCRF fully mediated the effects of age on CBF in the gray matter, but not in the white matter. Additionally, regional measures of CBF were related to regional measures of brain volume. These findings provide evidence that age-related effects on cerebrovascular health and perfusion in older adults are largely influenced by their eCRF levels.
A paradigm for distributed debugging

Three critical problems associated with distributed debugging are controlling the debugging process in the absence of a global clock; maintaining transparency so that the debugger does not change the order or timing of events, and reproducing an execution sequence to be able to verify that a fault has been corrected. A paradigm is put forward that successfully addresses these three problems. To demonstrate the feasibility of this paradigm, an instantiation has been constructed. A description is given of the resulting debugger for a dataflow language.
Safety-Driven Design for Software-Intensive Aerospace and Automotive Systems

Too often, systems are designed and then an attempt is made to add safety features or to prove that the design is safe after the fact. Safety has to be designed into a system from the start-it cannot be effectively added on to a mature design. In addition, the increasing use of software is changing the nature of accident causation in software-intensive systems and our safety engineering techniques must change accordingly. This article will describe a new hazard analysis technique, called STPA, which is effective on software-intensive systems. An advantage of this technique is that it can be used to drive the earliest design decisions and then proceed in parallel with ensuing design decisions and design refinement. Not only is this approach more effective, but the cost is no more than a more conventional design process and potentially much cheaper.
Minimum Number of Genes Controlling Cotton Fiber Strength in a Backcross Population

Textile mills in the USA require strong cotton fiber (Gossypium hirsutum L.) for modern high-speed textile operations. The primary objective of this study was to determine the inheritance of strength descending from FTA 263-20 (FTA). FTA was developed by introgression into G. hirsutum from G. arboreum L., G. thurberii Todaro, and G. barbadense L. Five backcrosses (BCs) into 'Deltapine 16' (DP 16) followed by six BCs into DP 90ne were made. In 2001, three sets of 64 BC 6 F 2 :F 3 progenies were evaluated for strength. Significant variability for F 2 :F 3 strength (F = 2.79), yield, three yield components, and four other fiber traits were detected. From a three replication test, strength gene number(s) estimates ranged from 1.10 to 1.29 and combined over sets was 1.23 genes. Average strength for the three BC 5 parents was 10.3% greater than DP 90ne and yield was 16.9% less. Strength was highly correlated with lint percentage, boll weight, seed weight, and 2.5% span length. Gene numbers for these correlated traits ranged from 0.02 for micronaire to 1.04 for yield. A separate study involving the BC 5 parents, 'Deltapine 90' (DP 90) and DP 90ne was used to determine the major physical components of strength. Fineness and individual fiber strength had no effect. Short fiber content significantly impacted strength as the three BC 5 parents average short fiber was 6.7 versus 8.7% for the DP 90s. The BC, parents average strength was 11% higher, 240 vs. 219 kN m kg -1 , and its yield was 9.0% lower than DP 90ne. Probably a single major gene or closely linked cluster of genes resulted in increased fiber strength.
Electrical inhibition of preterm birth: inhibition of uterine contractility in the rabbit and pup births in the rat.

Objective: The purpose of this study was to inhibit uterine contractility during parturition with an electrical current, which is called electrical inhibition, in the rabbit and the rat. Study design: We studied the electrical inhibition of in vitro spontaneously contracting preterm or term gestational rat myometrium tissue and in vivo spontaneously contracting uterus either directly in the rabbit and rat or transvaginally in the rat. Values for myometrial tension, intrauterine pressure, pup birth intervals, and electromyographic activity before and after electrical inhibition were compared. Results: Electrical inhibition decreased rat in vitro myometrial tension by 50%, decreased in vivo rabbit intrauterine pressure by 48%, decreased in vivo rat intrauterine pressure by 80%, and increased birth intervals (latency) by factors of 50 (direct electrical inhibition) and 20 (transvaginal electrical inhibition). All electromyographic activity parameters were reduced significantly. Conclusion: Electrical inhibition of the uterus is possible. Electrical inhibition is rapid and localized; the duration can be prolonged, and the reversibility is spontaneous. Electrical inhibition may be a new method of tocolysis in the human.
A comparative study of the effects of hydrochlorothiazide and amiloride on kidney calcium content in calcitriol-treated rats

Abstract Hydrochlorothiazide and amiloride have been used in combination to reverse the hypercalciuria induced by calcitriol (1,25-dihydroxyvitamin D 3 ) administration. In order to evaluate the fate of the retained calcium under conditions of chronic diuretic use, forty-two male, weanling Sprague Dawley rats were randomly assigned to control and treatment groups for four weeks. The animals were fed laboratory rat chow. The hydrochlorothiazide at 3 mg/kg/day, amiloride at 0.6 mg/kg/day and calcitriol at 20 or 50 ng/kg/day were given by stomach tube. Our results demonstrated that with the concurrent administration of amiloride and calcitriol at conventional therapeutic dosages, the total calcium content of the whole kidney was decreased without affecting the femur calcium concentration. The hydrochlorothiazide-treated rats, compared with the amiloride-treated rats, had a higher concentration of total kidney calcium (206–213 versus 183–188 μg/g dry weight; p
The unwind property for programs with bounded memory

Abstract For programs that can access unbounded memory (e.g., flowchart programs with recursion on simple variable parameters), the ‘unwind property’ is equivalent to the ‘truth-table property’. For programs restricted to bounded memory (e.g., flowchart programs with parameterless recursion), the two properties are not equivalent in general. We recapitulate all known results, give new results, and establish conditions under which the two properties are equivalent for program with bounded memory.
Magnetorheological finishing (MRF) of potassium dihydrogen phosphate (KDP) crystals: nonaqueous fluids development, optical finish, and laser damage performance at 1064 nm and 532 nm

Over the past year we have been working on specialized MR fluids for polishing KDP crystals. KDP is an extremely difficult material to conventionally polish due to its water solubility, low hardness, and temperature sensitivity. Today, KDP crystals are finished using single-point diamond turning (SPDT) tools and nonaqueous lubricants/coolants. KDP optics fabricated using SPDT, however, are limited to surface corrections due to tool/method characteristics with surface quality driven by microroughness from machine pitch, speed, force, and diamond tool character. MRF polishing offers a means to circumvent many of these issues since it is deterministic which makes the technique practical for surface and transmitted wavefront correction, is low force, and is temperature independent. What is lacking is a usable nonaqueous MR fluid that is chemically and physically compatible with KDP which can be used for polishing and subsequently cleaned from the optical surface. In this study, we will present the fluid parameters important in the design and development of nonaqueous MR fluid formulations capable of polishing KDP and how these parameters affect MRF polishing. We will also discuss requirements peculiar to successful KDP polishing and how they affect optical figure/finish and laser damage performance at 1064 nm and 532 nm.
Evaluation of Thymopoiesis Using T Cell Receptor Excision Circles (TRECs): Differential Correlation between Adult and Pediatric TRECs and Naı̈ve Phenotypes

To determine whether the thymus is still functional despite age-related involution, we measured a biomarker for thymopoiesis known as the T cell receptor excision circle (TREC) from peripheral blood mononuclear cells (PBMCs) of 148 healthy children and from PBMCs, CD4(+), and CD8(+) cells of 32, 30, and 50 healthy adults, respectively. We demonstrate that during the first 5 years of life, thymic output is decreased (P 0.002) but not dramatically (r = -0. 282). Among adults aged 23-58, thymic output was inversely correlated with age, as measured from PBMCs (r = -0.628, P < 0.0005), CD4(+) (r = -0.530, P 0.003), and CD8(+) fractions (r = -0.385, P 0. 006). A strong correlation existed between pediatric PBMC TRECs and the expression of three naive phenotypic markers (CD45RA(+)CD45RO(-), CD45RA(+)CD62L(+), and CD45RO(-)CD27(+)CD95(low)). Adult PBMC TRECs correlated only with the expression of CD45RA(+)CD45RO(-) (r = 0.459, P 0.012). Our data suggest that in adults CD45RA(+)CD45RO(-) may be enriched for TRECs and add to a growing body of evidence illustrating intact thymic function in adulthood.
The validity of male patients' self-reports regarding prostate cancer screening.

Background.Despite the high rate of prostate cancer screening, the accuracy of male patients' self-reports of screening has not been investigated. This study assessed the concordance between patients' self-reports of prostate screening and the medical record. Methods.Focus groups were conducted to obtain male patients' perceptions of prostate cancer screening and salient terminology. A sample of males (n= 276), 40 years of age or older, completed a 15-item questionnaire. Patients' self-reports of PSA and DRE screening were then compared with medical records. Results.Results showed that patients' self-reports of DRE and PSA were discordant with the medical record 32 and 29% of the time, respectively. Sensitivity of patients' self-reports for DRE and PSA was 82 and 74%, respectively. Specificity of patients' self-reports for DRE and PSA was 56 and 65%, respectively. One in five patients reported that they were not sure how a doctor checks a man's prostate gland. Only 39% of patients knew that the prostate gland can be checked by a blood test. Conclusions.There were significant differences between patients' self-reports and the medical record. The results should be of concern to primary care practitioners and to those who evaluate the efficacy of prostate cancer screening programs.
Origin of major element chemical trends in DSDP Leg 37 basalts, Mid-Atlantic Ridge

Abstract In this paper we summarize the major element chemical variation for basalts from the Deep Sea Drilling Project Leg 37 and relate it to stratigraphic position in each of five drilling sites. Least-squares techniques are successfully used to quantify the nature and extent of alteration in these basalts, and to correct the major element analysis back to a magmatic, or alteration-free, composition on the assumption that alteration takes place in two ways: (1) secondary minerals are introduced into veins and vesicles, and (2) CO 2 and H 2 O react with components in the rock to form a simple alteration assemblage. A chemical stratigraphy is defined for these basalts by grouping lavas whose chemistries are related by low-pressure phenocryst-liquid differentiation as identified by least-squares calculation. Major chemical-stratigraphic units are as much as 200 m thick; correlations of these units can be made between the holes at site 332 (about 100 m apart), but not between the other sites. Compositions of parental magmas are calculated by extrapolating low-pressure variations to a constant value of 9% MgO. The differences in these extrapolated compositions reflect high-pressure processes, and suggest that clinopyroxene may be an important phase in either intermediate-level fractionation of basaltic liquids, or as a residual phase during the partial melting which produces these basaltic liquids. Several of the basaltic liquids calculated as parental to the Leg 37 basalts have CaO contents greater than 14% and indicate that the oceanic mantle is richer in CaO and Al 2 O 3 than values used in pyrolite models for the upper mantle. A model for magma generation and eruption beneath the Mid-Atlantic Ridge embodies the following characteristics: 1. (1) Separate magma batches are generated in the mantle. 2. (2) Each of these may be erupted directly or stored at shallow depth where significant fractionation takes place. Common fractionation processes are inferred to be gravitative settling of olivine, flotation (?) of plagioclase, and flow differentiation of an olivine-plagioclase-augite assemblage. 3. (3) Eruption of fractionated lava derived from earlier magma batches may alternate with eruption of younger less-fractionated or unfractionated magma.
The influence of mosquito control recirculation ditches on plant biomass, production and composition in two San Francisco Bay salt marshes

Abstract Vegetation of two San Francisco Bay, California, U.S.A. tidal marshes was examined to determine the effects of recirculation ditches designed to eliminate mosquito-breeding. Salicornia virginica L. biomass and production in Petaluma Marsh and plant species composition in Suisun Marsh were measured with respect to distance from ditches and natural channels. In Petaluma Marsh, both annual above-ground production estimates and infrared aerial photographs indicated that S. virginica growth rates were higher near ditches than in the open marsh. In the floristically diverse, less saline Suisun Marsh, there was a displacement of the more salt tolerant S. virginica by the less tolerant Juncus balticus Willd. and a significantly greater number of species near the ditches. Results in both marshes are correlated with low groundwater salinities near ditches and suggest that tidal circulation within ditches locally ameliorates extremes in soil conditions.
Developmental profile of NGF immunoreactivity in the rat brain: a possible role of NGF in the establishment of cholinergic terminal fields in the hippocampus and cortex.

Abstract In the current investigation, we have examined the developmental profile of nerve growth factor immunoreactivity (NGF-ir) in the postnatal rat. During the first 3 weeks after birth, NGF-ir was observed within the hippocampal mossy fiber region, where it persists throughout adulthood and appeared transiently within three additional zones – the dentate gyrus supragranular zone, the tenia tecta/intermediate lateral septum, and the cingulate/retrosplenial cortex. In all cases, the appearance of NGF-ir progressed in a rostrocaudal pattern over time. A strong correlation was seen between the pattern of NGF-ir and cholinergic innervation in the dentate gyrus supragranular zone, both spatially and temporally, suggesting that NGF may direct the innervation of cholinergic afferents to this region. A spatial correlation was also observed between NGF-ir and cholinergic innervation within the retrosplenial cortex and tenia tecta. With our current techniques, however, we were unable to determine at what point during development the adult-like pattern of cholinergic terminal innervation in these regions occurred and, thus, were not able establish a temporal correlation in these regions. Within the cingulate cortex, there was no evidence suggesting that the developmental appearance of NGF-ir in this region was associated with a specific enhancement of cholinergic innervation. Thus, the results of the current investigation clearly identify the presence of transiently occurring zones of NGF-ir during postnatal CNS development, although defining their exact functional role will require additional investigation.
The Archaeological Study of Empires and Imperialism in Pre-Hispanic Central Mexico

Abstract The hegemonic-type empires of ancient Mesoamerica are difficult to study archaeologically because they left fewer material traces than more territorially organized empires such as the Inka or Roman cases. We present a material culture model for the identification of such empires using archaeological data. The model, based upon Michael Doyle's analytical approach to imperialism, is developed from historical and archaeological research on ancient empires from the Old World and South America. Empires can be identified from three types of evidence: characteristics of the capital city, evidence for varying types of political domination of provincial areas, and examples of the projection of influence in a larger, international context. We apply this model to archaeological data on three central Mexican cases—Tenochtitlan, Teotihuacan, and Tula. The results suggest that both Tenochtitlan and Teotihuacan ruled empires, whereas Tula did not.
Increment thresholds of the three spectral mechanisms in the retina of the California ground squirrel (Spermophilus beecheyi)

Increment threshold (IT) functions were obtained for the electroretinogram (ERG) and for single units in the optic nerve of the California ground squirrel. The three spectral mechanisms providing input to ganglion cells in this retina were isolated and their increment thresholds to large field, long-duration stimuli were examined. Mean IT functions for the 519 nm mechanism (irrespective of unit class), the 500 nm mechanism, and the ERG all showed shallow log-log slopes between 0.52 and 0.63. The slope of the mean IT function for the 440 nm mechanism depended on the spectral character of the adapting light. When the dominant wavelength of this light was close to the peak sensitivity of the 440 nm mechanism, the mean IT function was steep (0.92), but when the dominant wavelength of the adapting light was at the cross-point of the opponent cells, the slope of the function was shallow (0.49). The difference in IT slope under these two conditions may be attributed to an additional sensitivity loss occuring at a spectrally-opponent site.
A prospective, randomized, multicenter, controlled study of the safety of Seprafilm adhesion barrier in abdominopelvic surgery of the intestine.

INTRODUCTION: Seprafilm® adhesion barrier (Seprafilm®) has been proven to prevent adhesion formation after abdominal and pelvic surgery. This article reports safety results, including the postoperative incidence of abdominal and pelvic abscess and pulmonary embolism, from a large, multicenter trial designed to evaluate the safety and effectiveness of Seprafilm® for reduction of adhesion-related postoperative bowel obstruction after abdominopelvic surgery. METHODS: A total of 1,791 patients participated in this prospective, randomized, multicenter, multinational, single-blind, controlled study in patients undergoing abdominopelvic surgery, the majority of whom had inflammatory bowel disease. Just before closure of the abdomen, patients were randomized to a Seprafilm® or no-treatment control group. Patients received an average of 4.4 and as many as 10 Seprafilm® adhesion barriers applied to organs and tissue surfaces that sustained direct surgical trauma and to suspected adhesiogenic surfaces. Complications that occurred within the first month after surgery were evaluated. RESULTS: During the safety evaluation period, the difference between the Seprafilm® and control groups for the incidence of abscess (4 vs. 3 percent, respectively) or pulmonary embolism ( 0.05). Foreign body reaction was not reported in either group. Fistula (2 vs. <1 percent) and peritonitis (2 vs. <1 percent) occurred more frequently (P ≤ 0.05) in the Seprafilm® group. In a subpopulation of patients in whom Seprafilm® was wrapped around a fresh bowel anastomosis, leak-related events, which included anastomotic leak, fistula, peritonitis, abscess, and sepsis, occurred more frequently (P ≤ 0.05). There were no other differences in the incidence, severity, or causative relationship of complications between study groups. CONCLUSIONS: This study confirmed the safety of Seprafilm® adhesion barrier with respect to abdominal abscess, pelvic abscess, and pulmonary embolism when administered to patients undergoing abdominopelvic surgery. Foreign body reaction was not reported for any patient. However, wrapping the suture or staple line of a fresh bowel anastomosis with Seprafilm® should be avoided, because the data suggest that this practice may increase the risk of sequelae associated with anastomotic leak.
Multidisciplinary Design Optimization for Complex Engineered Systems Design: State of the Research and State of the Practice—Report From a National Science Foundation Workshop

Multidisciplinary design optimization (MDO) has evolved remarkably since its inception 25 years ago. Despite these advances, the design of complex engineered systems remains a challenge, and many large-scale engineering projects are routinely plagued by exorbitant cost overruns and delays. To gain insight into these challenges, 48 people gathered from industry, academia, and government agencies to examine MDO’s current and future role in designing complex engineered systems. This paper summarizes the views of five distinguished speakers on the “state of the research” along with the discussions from an industry panel of representatives from Boeing, Caterpillar, Ford, NASA Glenn Research Center, and United Technologies Research Center on the “state of the practice”. This paper also summarizes the future research topics identified by breakout groups in five key areas: (1) modeling and the design space; (2) metrics, objectives, and requirements; (3) coupling in complex engineered systems; (4) dealing with uncertainty; and (5) people and workflow. Finally, five over-arching themes are offered to advance MDO. First, we need to engage more disciplines outside of engineering and look for opportunities to use MDO outside of its traditional areas. Second, MDO problem formulations must evolve to encompass a wider range of design criteria. Third, we need effective strategies for putting designers “back in the loop” during MDO. Fourth, we need to do a better job of publicizing the successful examples of MDO so that we can improve the “buy in” that is needed to advance MDO in academia, industry, and government agencies. Fifth, we need to better educate our students and practitioners on systems design, optimization, and MDO along with their benefits and drawbacks.Copyright © 2011 by ASME
Sequencing and expression of aadA, bla, and tnpR from the multiresistance transposon Tn1331.

Abstract A fragment of Tn1331 includingtnpR, aac, aadA,and abla gene which encodes lower levels of resistance to ampicillin and carbenicillin as compared to those mediated by the TEM β-lactamase was sequenced. The polypeptide encoded by thebla gene has homology with the OXA-1, PSE-2, and OXA-2 proteins. Genesaac and bla are upstream and downstream respectively ofaadA, and are both flanked by recombinational hot spots. Tn1331 has 520-bp direct repeats which include parts of thetnpR and TEMbla genes. Evolutionary models for the genesis of Tn1331 are proposed.
The influence of composition and processing parameters on the mechanical properties and erosion response of Ni + TiB2 coatings

Sputtered Ni + TiB2 coatings have been shown to protect Inconel* 718 and Ti-6A1-4V substrates from solid particle erosion. However, before new erosion-resistant coatings can be efficiently designed, it is essential that the role of mechanical properties in determining erosion resistance be fully understood. In this investigation, nanoindentation techniques were used to quantify the effects of substrate preparation, coating composition, and sputtering process parameters on the elastic moduli and indentation hardness of thin coatings deposited on Ti-6A1-4V and Inconel 718 substrates. The influence of these parameters on coating adhesion was determined using a conventional scratch test. Elastic moduli, indentation hardnesses, and coating adhesion were correlated with erosion behavior. The erosion resistance of those coatings that exhibited microscopic ductility is dependent on the nodule diameter and coating properties such as hardness, elastic modulus, and fracture toughness.
Hematology of a murine beta-thalassemia: a longitudinal study.

Mice homozygous for a spontaneous mutation, in which the ..beta..-major globin gene is deleted, have clinical symptoms of ..beta..-thalassemia. These mice have a hypocellular, hypochromic, microcytic anemia that becomes more severe with increasing age. The defective red cell morphology, decreased osmotic fragility of erythrocytes and shortened red cell life span found in ..beta..-thalassemic mice are similar to those observed in human ..beta..-thalassemia. Synthesis of ..beta..-globin is depressed but not as much as might be expected because the expression of the..beta..-minor globin gene is enhanced to encode two to three times more globin than in normal mice. Splenomegaly, an enlarged pool of stem cells for erythropoiesis, and iron overloading occur in older mice. The fact that these mice remain moderately healthy makes them a very suitable animal model in which to develop and test alternative techniques of gene therapy that could be successfully applied to the treatment of human thalassemia. Homozygous ..beta..-thalassemic mice have large deposits of iron in their tissues, which might make these mice also useful for in vivo tests of the effectiveness and possible long-term side effects for newly developed iron chelators.
Brownian dynamics simulation of polarized light scattering from wormlike chains

The technique of Brownian dynamics simulation is used to study polarized dynamic light scattering from semi-stiff models of polymers. The primary objective is to determine how sensitive the dynamic scattering form factor, S(q, t), is to dynamic flexibility as opposed to static flexibility (average conformation). S(q, t) over a range of experimentally accessible scattering vector (q) are derived from the dynamical trajectories of many different chains initially selected from an equilibrium ensemble. In order to minimize noise, which is of crucial importance in order to accurately characterize the low amplitude, fast decay components of S(q, t), the center of diffusion or mass is subtracted from the polymer coordinates in most simulations. This procedure, which is valid for systems that have weak coupling between overall translational and rotational motions, has the additional advantage of simplifying S(q, t) since the contribution of overall translation has been factored out. In the analysis of experimental data, premultiplying S(q, t) by exp (+q2 Dt) where D is the translational diffusion constant has the same effect. Simulations are described for dynamically rigid and flexible wormlike chains with variable persistence length (P equals 40 to 100 nm) and contour length corresponding to 762 bp DNA. S(q, t)'s with and without overall translation are analyzed with CONTIN in order to determine lifetime distributions. For large P (> 70 nm), rigid and flexible models are indistinguishable. However, differences are observed when P is less than 70 nm as far as the faster decay components are concerned. The amplitude of the faster decay components are the same for rigid and flexible models but the lifetimes are significantly shorter for the flexible case. For the rigid case, the 'first internal time' corresponds to where (theta) is the end-over-end rotational diffusion constant. Finally, the simulation results are compared with actual light scattering experiments on 762 bp DNA. A flexible model with P equals 50 nm is in best agreement with experiment. All of the rigid models predict a first internal time that is too long by 40% or more.