cssi/SciSciGPT-SciSciNet huggingface dataset:
A numerical method for an inhomogeneous nonlinear diffusion problem

A numerical method for the solution of an inhomogeneous nonlinear diffusion problem that arises in a variety of applications is presented. The diffusion coefficient in the underlying diffusion process is concentration- as well as distance- dependent. We wish to determine the concentration of the diffusing substance in a semi-infinite domain at any time, starting with a given initial concentration. The method of solution begins by first mapping the semi-infinite physical domain to a finite computational domain. An implicit finite-difference marching procedure is then used to advance the solution in time. Numerical results are presented for several physical problems. We observe that the present numerical solutions are in good agreement with the analytical solutions obtained previously by other researchers.
Deuterium tracer studies on cobalt catalyzed Fischer–Tropsch synthesis: Addition of alcohols

Abstract Unlike the iron catalyzed Fischer–Tropsch (FT) synthesis, the additions of ethanol-d 6 and 2-propanol-d 8 during the Co/SiO 2 catalyzed FT reactions did not produce detectable amount of deuterated isomer in any alkane. However, when the FT reactions were conducted over a mixture of FT catalyst Co/SiO 2 and dehydration catalyst Al 2 O 3 , the d 1 , d 2 and d 3 isomers of alkanes from C 7 to C 15 were obtained with a nearly constant D/molecule value of 1.4 when ethanol-d 6 was used as the tracer while d 1 –d 6 isotopic isomers of alkanes were observed with a nearly constant D/molecule value of 2.3 when 2-propanol-d 8 was used. The similar results were obtained when 1-propanol was used as the tracer. These results lead us to conclude that the C 2 or C 3 species that initiates the chain growth in the FT reaction resembles ethene or propene. The pathways for the formations of ethylidene and propylidene were proposed.
De novo expression of pp125FAK in human macrophages regulates CSK distribution and MAP kinase activation but does not affect focal contact structure.

The protein tyrosine kinase pp125FAK (focal adhesion kinase, or FAK) is expressed by a variety of cell types and has been implicated in integrin-mediated signaling events. We explored the potential functions of FAK by expressing it de novo in a cell type lacking FAK. We showed previously that cultured human macrophages lack FAK yet still have well-formed focal contacts. Adenovirus-mediated expression of FAK results in the appearance of FAK protein, which localizes to focal contacts and becomes tyrosine-phosphorylated without perturbing overall cell morphology or focal contacts. FAK associates with CSK 48 h after infection and recruits it to focal contacts. Tyrosine phosphorylation of p130cas but not of paxillin is stimulated after FAK expression. The phosphorylation of p130cas is lost at 48 h in parallel with CSK accumulation in focal contacts. The ERK2 form of MAP kinase is similarly activated at 12–24 h, but it also returns to low levels at 48 h. These findings demonstrate that FAK can be reconstituted to focal contacts in cells that lack it without affecting cell morphology or focal contact structure. FAK can regulate the distribution and activities of elements of the MAP kinase signaling pathway. J Cell Physiol 178:164–172, 1999. Published 1999 Wiley-Liss, Inc.
Voltage polarity effects in GST-based phase change memory: Physical origins and implications

We show that bias polarity can greatly accelerate device failure in GST- based (GeSbTe) PCM devices, and trace this effect to elemental segregation, initially driven by bias across the melt but then enhanced during the crystallization process. Implications include device, pulse, and materials design for high endurance.
A variable buffer-size model and its use in analyzing closed queueing networks with blocking

We present a model which enables efficient analysis of certain types of closed queueing networks with blocking due to limited buffer spaces. The networks analyzed are those in which the limited buffers occur in tandem subnetworks. A new model, with variable buffer-size, is introduced as a conceptual tool to model part of a tandem network with blocking, using only product-form submodels. Using this model we iteratively solve for the whole network. The technique is illustrated first for a simple system with tandem queues, and then for more complex systems. The method is compared with exact solutions or simulations, and found to be reasonably accurate. The method is easily implemented using standard software for closed queueing networks. Given the complexity of the blocking problem, our approach offers a simple and efficient alternative to exact analysis.
Protein, glycoprotein and glycolipid profiles of human arterial and venous tissues

Abstract Selected normal human arteries and veins were solubilized with detergents, neutral salt buffers and organic solvents. Comparative sodium dodecyl sulphate polyacrylamide gels and thin layer chromatographic plates were developed and the patterns compared. The low molecular weight periodic acid—Schiff positive band seen in crude detergent extracts of vascular tissue is predominantly glycolipid. Arterial and venous tissues closely resemble one another with only minor differences in the glycoprotein and glycolipid patterns.
Existence of a phase transition in reggeon field theory in two transverse dimensions

Abstract We show that a reggeon field theory, in the physical number of dimensions, with a linear bare trajectory and a constant triple-pomeron coupling, undergoes a phase transition as the bare pomeron intercept is increased through a certain critical value.
The classical Guyton view that mean systemic pressure, right atrial pressure, and venous resistance govern venous return is/is not correct

The following letter is in response to the Point:Counterpoint series “The classical Guyton view that mean systemic pressure, right atrial pressure, and venous resistance govern venous return is/is not correct” that appeared in the November 2006 issue (vol. 101: 1523–1527). Magder ([3][1])
Insertion of Molecular Oxygen into a Palladium−Hydride Bond: Computational Evidence for Two Nearly Isoenergetic Pathways

The reaction of a palladiumII−hydride species with molecular oxygen to form palladiumII−hydroperoxide has been proposed as a key step in Pd-catalyzed aerobic oxidation reactions. We recently reported one of the first experimental precedents for such a step (Angew. Chem., Int. Ed. 2006, 45, 2904−2907). DFT calculations have been used to probe the mechanism for this reaction, which consists of formal insertion of O2 into the palladium−hydride bond of trans-(NHC)2Pd(H)OAc (NHC = N-heterocyclic carbene). Four different pathways were considered: (1) hydrogen atom abstraction (HAA) of the Pd−H bond by molecular oxygen, (2) reductive elimination of HX followed by oxygenation of Pd0 and protonolysis of the (η2-peroxo)−PdII species, (3) oxygenation of palladiumII−hydride with subsequent reductive elimination of the O−H bond from an η2-peroxo−PdIV center, and (4) formation of a cis-superoxide adduct of the palladium−hydride species followed by O−H bond formation via hydrogen atom migration. The calculations reveal...
Regulatory Elements in Noncoding DNA in the Chromosome 9p21 Locus

1. Harismendy O, Notani D, Song X, Rahim NG, Tanasa B, Heintzman N, Ren B, Fu XD, Topol EJ, Rosenfeld MG, Frazer KA. 9p21 DNA variants associated with coronary artery disease impair interferon-g signalling response . Nature. 2011;470(7333):264–268. PMID: 21307941. ### Study Hypothesis A novel locus on chromosome 9p21 has been identified in numerous genome-wide association studies as the most highly associated with coronary artery disease (CAD) and myocardial infarction. Understanding the mechanism by which the locus influences disease has been a challenge because the locus lies entirely within noncoding DNA—in a so-called “gene desert” at a long distance from the closest genes. The authors hypothesized that common DNA variants in the locus alter transcriptional regulatory elements that engage in long-range interactions with and modulate expression of genes outside of the locus.1 ### How Was the Hypothesis Tested? The authors integrated multiple data sets to identify potential transcriptional regulatory elements in the 9p21 CAD locus. They searched in various types of human cells for chromatin modification “marks” of 3 types—promoters marked by enrichment of histone H3 trimethylated at lysine 4 (H3K4me3); insulators marked by CTCF-binding sites; and enhancers marked by enrichment of histone H3 monomethylated at lysine 4 (H3K4me1), or p300- and MED1-binding sites, or presence of DNase hypersensitivity sites. They …
Semigroups satisfying variable identities

The purpose of this note is to generalize a theorem of Tamura’s [3] providing a self-contained and, we think, more elementary proof than Tamura’s in that it avoids using the theory of contents. Tamura’s result states that a semigroup S satisfies an identify xy=f(x,y) with f(x,y) a word of length greater than 2 which starts with y and ends in x if and only if S is an inflation of a semilattice of groups satisfying the same identity. We investigate semigroups as in Tamura’s Theorem, except that we permit f(x,y) to vary with x and y.
Production, Hedging, and Speculative Decisions with Options and Futures Markets

This paper analyzes production, hedging, and speculative decisions when both futures and options can be used in an expected utility model of price and basis uncertainty. When futures and option prices are unbiased, optimal hedging requires only futures (options are redundant). Options are used together with futures as speculative tools when market prices are perceived as biased. Straddles are used to speculate on beliefs about price volatility and to hedge the futures position used to speculate on beliefs about the expected value of the futures price. Mean-variance analysis in general is not consistent with expected utility when options are allowed. One extension of Sandmo's expected utility model of the competitive firm under price uncertainty considers the use of futures or forward contracts. Danthine; Holthausen; and Feder, Just, and Schmitz show that without basis uncertainty the optimal output level is not affected by price risk; also, with an unbiased futures price, the optimal hedging level of the competitive firm is the full hedge, while a biased futures price will result in a partly speculative hedge. Related works include Batlin, who allows for basis risk in the form of imperfect time hedging; Paroush and Wolf, and Antonovitz and Nelson, who consider basis risk with the simultaneous availability of futures and forward contracts; Grant, Honda, Losq, Newbery and Stiglitz, and Rolfo, who allow for production uncertainty; Chavas and Pope, who allow for production uncertainty and hedging costs; and Karp, who considers the problem in a dynamic setting. This paper provides a further extension of this analysis by allowing options as a means of coping with price risk. With the introduction of commodity options on futures for many commodities in the 1980s, this problem appears relevant to a number of production settings, especially in agriculture. Specifically, this paper considers the simultaneous choice of a production level and of hedging levels of futures and options within the general expected utility model. The model allows for basis uncertainty, but the production process is assumed to be nonstochastic.
Isolated lung perfusion with FUDR is an effective treatment for colorectal adenocarcinoma lung metastases in rats

Currently, the only treatment capable of significantly prolonging survival in patients with isolated pulmonary metastases from colorectal adenocarcinoma is complete resection. Systemic chemotherapy has been shown to provide little benefit. We evaluated the efficacy of highdose, organ-specific 2′-deoxy-5-fluorouridine (FUDR) using a model of isolated single-lung perfusion (ILP) in the rat. On day 0, 28 BDIX rats were inoculated intravenously with 10 6 viable Sp-5 colorectal adenocarcinoma cells. On day 10 after-tumor inoculation, animals were randomized into five treatment groups. Group I received a continuous intravenous infusion of FUDR (1 mg ⋅ kg −1 ⋅ d −1 ) for 7 days administered by an osmotic minipump. Group II underwent isolated left lung perfusion with a buffered Hespan solution, groups III to V underwent ILP with 3.5, 7, and 14 mg of FUDR per milliliter of the buffered Hespan solution, respectively. Animals undergoing ILP were anesthetized with pentobarbital, intubated, and ventilated, and then underwent left thoracotomy with cannulation of the pulmonary artery; the pulmonary artery and vein were clamped proximally. Groups II to V were perfused for 20 minutes at a rate of 1 mL/min, followed by a 5-minute washout with FUDR-free buffered Hespan solution. On day 26 after tumor inoculation, the animals in all groups were sacrificed and their lungs were stained and counted. Animals that underwent ILP with 14 mg of FUDR per milliliter of the buffered Hespan solution showed a significant decrease in the number of tumor nodules on the treated side versus the number on the untreated side (455.2 ± 87.3 versus 11 ± 6.4; p p
Animal scale-up

The title of this paper is freely adapted from a problem common to the art and science of chemical engineering: “plant scale-up” or “process scale-up.” A chemical reaction or a set of chemical reactions is discovered which leads to a potentially useful product. The basic chemistry is worked out, often in considerable detail, at the bench in glassware. It is necessary to design a plant which will make the product economically and consistent with other constraints imposed by society.
Neonatal diabetes mellitus.

This is a case report of a newborn infant with neonatal diabetes mellitus who showed evidence of marked hyperglycemia at 32 hrs of age. Immunoassay of serum insulin was markedly inappropriate for the elevated blood glucose concentration. The B-cells in the islets of Langerhans were reduced in number and in their content of cytoplasmic granules. Diagnostic aids and treatment are discussed.
POLICY TERMINATION: THE CASE OF TERM LIMITS IN MICHIGAN

This article tests a theoretical framework by examining a case study of term limits in the Michigan legislature. The Michigan case tests the “fit” of Daniels's seven generalizations about policy and organizational termination. The goal of this paper is to extend the discussion of termination policy to the issue of term limits and formulate an agenda for future research that can develop a better understanding of term limits based on the concept of termination.
The ovariectomized, lactating rat as an experimental model for osteopenia: calcium metabolism and bone changes

The ovariectomized, lactating rat (Sprague-Dawley) is proposed as an experimental model for the rapid development of osteopenia which may be used to test the effectiveness of bone-retentive drugs potentially useful in treating osteoporotic women. Rats were ovariectomized (OVX) on day 2 postpartum and were kept on a low-calcium diet (0.1%). Measurements of serum total calcium, ionic calcium, albumin and parathyroid hormone were conducted between days 4 and 21 of lactation. Serum total and ionic calcium and albumin were significantly lower and serum parathyroid hormone was significantly higher in all lactating rats at 16 days postpartum compared to nonlactating controls. Mean bone mass of the femurs of OVX lactating rats measured at day 21 was approximately 50% of that of non-lactating intact controls. The enhanced duodenal calcium absorption (in everted gut sacs) associated with lactation was not affected by OVX and neither was the average litter weight gain between 2 and 14 days of lactation. In conclusion, lactation coupled with a low-calcium diet resulted in marked osteopenia, depressed serum calcium (both total and ionic) and significantly elevated serum parathyroid hormone concentration. The rapid and extensive bone loss of this model makes it appropriate for the study of therapeutic agents designed to retain bone mass.
Differences Between Self‐Adapted and Computerized Adaptive Tests: A Meta‐Analysis

Self-adapted testing has been described as a variation of computerized adaptive testing that reduces test anxiety and thereby enhances test performance. The purpose of this study was to gain a better understanding of these proposed effects of self-adapted tests (SATs); meta-analysis procedures were used to estimate differences between SATs and computerized adaptive tests (CATs) in proficiency estimates and post-test anxiety levels across studies in which these two types of tests have been compared. After controlling for measurement error, the results showed that SATs yielded proficiency estimates that were 0.12 standard deviation units higher and post-test anxiety levels that were 0.19 standard deviation units lower than those yielded by CATs. We speculate about possible reasons for these differences and discuss advantages and disadvantages of using SATs in operational settings.
Evolving Pliocene-Pleistocene climate: A North Pacific perspective

Abstract Siliceous microfauna in sediments from North Pacific Deep Sea Drilling Project sites record the response of the regional surface and near-surface waters to global climate change over the past 3.0 Ma. During the Late Pliocene (2.7–3.0 Ma), the northern subtropical and subpolar Pacific experienced warmer climate conditions than those of today. The first predominant polar assemblage maximum occurs in the North Pacific at ∼2.45 Ma signifying this region's response to the initiation of significant northern hemisphere glaciation. North Pacific faunal data show that Late Pliocene (1.8–2.5 Ma) glacial maxima were only about half to two-thirds as severe as those which occurred during the Late Pleistocene. Low faunal assemblage variability during a 200 ka interval in the latest Pliocene (1.6–1.82 Ma) in the North Pacific indicates minimal variations in the surface water properties and climate conditions most like those which existed just prior to 2.5 Ma. A distinct change in faunal assemblage registered in sediments from Site 580 between 1.2 and 1.2 Ma marks the first cooling in the North Pacific comparable in intensity to those of the Late Pleistocene. Since ∼1.26 Ma, high amplitude, high frequency variations in the North Pacific polar assemblage have continued to occur, providing further evidence that the interglacial/glacial extremes that characterize the Late Pleistocene have persisted since this time. The frequency distribution of North Pacific winter sea-surface temperature time series for the Late Pliocene and Early Pleistocene includes major concentrations of variance (power) centered at a frequency corresponding to a 41 ka period, with variance dominance of the temperature time series for the last 800 ka shifting to lower frequencies (∼110 ka period).
FORS: A software tool for flexible design

This paper is a description of FORS (Flexible Organizations), a design environment based on a network representation of the design effort. Each design network consists of: (a) Tools (software programs distributed over the whole network of computers) and (b) Aspects (models to which the tools are applied). The system's communication and exchange of data are based on distributed problem-solving techniques. FORS provides an icon based interface, allows for the dynamic reconfiguration of the design network, maintains libraries of records, tools and aspects, and attempts to develop mechanisms for collaboration between the different tools. The addition and the deletion of tools are relatively easy and the user has the ability to access information and data from previous design efforts. FORS is a new approach to design environments because it gives equal emphasis on the tools and the data used in the design effort. FORS embodies some old ideas, like object-oriented representation of the tools, but simultaneously extends these and creates a modular and flexible environment. One important aspect of FORS is the introduction of the issue of remote effects (the impacts that one design task can have on other tasks). FORS is currently being used in the mechanical design of an automobile window regulator; an implementation in the area of power systems is in progress.
Drinking variables, affective measures and neuropsychological performance: familial alcoholism and gender correlates.

Abstract The relationships between five measures of alcohol consumption and five summary measures of diverse neuropsychological test performances were studied in 76 male and 67 female alcoholics as a function of family history of alcoholism and affective symptomatology. No significant relationships were obtained between drinking variables and neuropsychological performance scores for the overall groups of male and female alcoholics. In family history positive (FH+) males, correlations between a number of drinking variables and neuropsychological measures neared significance. The Beck Depression Inventory (BDI) scores correlated most strongly with the overall impairment index in both family history positive (FH+) and family history negative (FH−) alcoholics. Depression and anxiety scores in the female alcoholics significantly correlated with three of the five alcohol consumption variables. Possible confounding factors in the relationships between alcohol intake measures and cognitive functioning were discussed.
Hypercontractive semigroups and two dimensional self-coupled Bose fields

We present an abstract perturbation theory for operators of the form H0 + V obeying four properties: (1) H0 is a positive self-adjoint operator on L2(M, μ) with μ a probability measure so that e−tH0 is a contraction on L1 for each t > 0; (2) e−TH0 is a bounded map of L2 to L4 for some T; (3) V ϵ Lp(M, μ) for some p > 2; (4) e−tV ϵ L1 for all t > 0. We then show that spatially cutoff Bose fields in two-dimensional space-time fit into this framework. Finally, we discuss some details of two-dimensional Bose fields in the abstract including coupling constant analyticity in the spatially cutoff case.
The Post-Hospital Outpatient Treatment of Pulmonary Tuberculosis by Prolonged Chemotherapy: A Study of Relapse Rate

Two hundred and two cases of pulmonary tuberculosis were studied on continuous long-term chemotherapy with a relapse rate of less than 1 per cent. One hundred and five control cases on short-term chemotherapy had a relapse rate of 30 per cent. All patients included cavitary, non-cavitary, surgical and non-surgical cases. It is our opinion that the minimum period of chemotherapy should be 18 to 24 months with no limit on the maximum length of time. We arbitrarily decided that five or more years of continuous chemotherapy would keep the relapse rate low.
Whole Mount Preparation of Chick Blastodermal Edge Tissue for Microscopic Examination

Three methods of preparation of chick blastodermal edge tissue for conventional microscopy were attempted: (1) Sections were cut from Water Wax (E. Gurr) embedded material. This method was unsatisfactory due to loss of morphological relationships produced by the inability to attach the tissue to a slide. (2) Frozen sections were cut from embryonic marginal tissue with its underlying white and yellow yolk which was embedded in a 25% gelatin solution. This method retained morphological relationships prior to 24 hr of egg incubation, but was technically impractical in excess of this period of incubation. Also, the gelatin could not be removed from the sections and cellular detail was obscured by its subsequent staining. (3) The blastoderm was removed from the yolk and adherent vitelline membrane, and the yolk dissected from a small piece of this blastodermal edge tissue under a dissecting microscope. The dissected tissue, primarily monocellular and dicellular in thickness, was transferred to a slide and atta...
Utilization of a wood-based syrup as a fermentation carbon source

An industrial by-product stream consisting primarily of α- and β-methyl xylosides supported microbial growth provided the treated syrup was diluted such that the osmotic pressure was within the range tolerated by the particular microorganism used. A culture screening study identified two organisms that efficiently utilized both α- and β-methyl xyloside. Xylose, α-, and β-methyl xylosides were all utilized simultaneously during batch growth ofArthrobacter sp. in a controlled-pH fermentor, although xylose was consumed faster than either xyloside. In addition,Arthrobacter sp. produced glucose isomerase when grown on the syrup.
The system dipotassium hydrogen phosphate-water at high temperatures (100–400°C); Liquid-liquid immiscibility and concentrated solutions

Abstract Phase equilibrium behavior in the condensed system K 2 HPO 4 H 2 O was determined at temperatures from 100 to 400°C. Solutions saturated with a solid, which is believed to be (nearly) anhydrous K 2 PO 4 , increase in K 2 HPO 4 content from 72 wt% at 100°C to 78 wt% at 400°C. A region of liquid-liquid immiscibility at compositions between 3 and 58 wt% was discovered, with a minimum temperature of 360°C. Separate experiments with saturating solids K 3 PO 4 , K 2 HPO 4 , and KH 2 PO 4 at 350°C indicated that each of these solids are in stable equilibrium with the solution phase, thus with no conversion to polyphosphate species.
Dynamic models and control strategies for wastewater treatment processes

Abstract Consideration of dynamic behavior and the incorporation of modern control systems can lead to substantial improvements in the performance of wastewater treatment plants. Other potential benefits include increased productivity, greater reliability, lower operational costs, more stable operation and faster start-ups. Several powerful tools are available for the study of dynamic behavior. Included among these are dynamic mathematical models, computer simulation, transient response analysis and process stability evaluation. Simple examples illustrating the theory and use of these tools are presented. The development of a control strategy is intimately related to the dynamic behavior of a process. Some of the basic questions which must be answered in developing a control strategy are: (1) What information should be collected? (2) How should the information be transmitted? (3) How should the information be processed? (4) What control actions should be taken? A wide variety of control algorithms are available for the processing of information for control. A discussion of several of these, on-off, PID. ratio, cascade, and feedforward, is presented and an example is given for the application of on-off control to a biological CFSTR. Digital computers are also being increasingly used for control of wastewater treatment plants and a discussion of computer control systems is presented. Examples of dynamic models and control strategies for two wastewater treatment processes, the step feed activated sludge process and the anaerobic digester, are presented and discussed, In addition, dynamic modeling and computer simulations are used to indicate those design and operational factors for the anaerobic digester which are effective in improving process stability. An effective control strategy for the activated sludge process is that provided by the step feed process which permits changing the points at which wastewater is added along the length of the reactor. Example control strategies for the anaerobic digester include the addition of base and the recirculation of the digested sludge. The effectiveness of the control strategy is dependent upon the type of forcing to which the digester is subjected.
Native Women Teacher Candidates “With Strength”: Rejecting Deficits and Restructuring Institutions

The authors highlight a southwestern university program that focused on recruiting and retaining Native American teacher candidates to increase the number of highly qualified teachers with a foundational imperative of cultural continuance of the Pueblo people. A secondary focus was the creation of a model professional development program that was sustainable and owned by the community. Utilizing Tribal Critical Race Theory, the authors tell the story of the candidates' struggles with and resistance to institutional inequity and oppression. Rejecting a view of the Native women as “at risk,” they are instead viewed as women “with strength.” The authors employed relational advocacy and operated through sustained local relationships to assist the candidates in navigating the teacher education program and the institution through the cultivation of academic cultural capital. Together, the teacher candidates and authors endeavored to challenge and transform the higher education institution to secure a reality of...
3-Hydroxy-3-methylglutaryl-CoA synthase: participation of invariant acidic residues in formation of the acetyl-S-enzyme reaction intermediate.

Inactivation of HMG-CoA synthase by a carboxyl-directed reagent, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), in a concentration-dependent and substrate-protectable manner suggested that the active site contains reactive acidic amino acids. This observation prompted functional evaluation of 11 invariant acidic amino acids by site-directed mutagenesis. Characterization of the isolated synthase variants' ability to catalyze overall and partial reactions identified three mutant synthases (D99A, D159A, and D203A) that exhibit significant diminution of k(cat) for the overall reaction (10(2)-, 10(3)-, and 10(4)-fold decreases, respectively). D99A, D159A, and D203A form the acetyl-S-enzyme intermediate very slowly (0.0025, 0.0026, 0.0015 U/mg, respectively, measured at pH 7. 0 and 22 degrees C) as compared to the wild-type synthase (1.59 U/mg), where intermediate formation approaches rate-limiting status. Differences in substrate saturation do not account for impaired activities or rates of intermediate formation. The structural integrity of the purified mutants' active sites is demonstrated by their abilities to bind a spin-labeled acyl-CoA analogue (R.CoA) with affinities and stoichiometries comparable to values measured for wild-type synthase. The impact of three distinct amino acids on reaction intermediate formation supports a mechanism of acetyl-S-enzyme formation that probably requires formation and directed collapse of a tetrahedral adduct. (18)O-induced shift of the (13)C NMR signal of (13)C acetyl-S-enzyme demonstrates that an analogous tetrahedral species is produced upon solvent exchange with the acetyl-S-enzyme. Partial discrimination between the functions of D99, D159, and D203 becomes possible based on the observation that D159A and D203A synthases exhibit retarded kinetics of solvent (18)O exchange while D99A fails to support (18)O exchange.
Research in situ.

Research performed where epidemics hit the hardest is necessary to bring solutions to the major health crises that plague poverty-stricken areas. Far from being limited to these areas, 'research in situ' can benefit health management worldwide. There are pressing technological needs to be addressed in order to facilitate such research.
Guest workers or unauthorized immigrants? The case of forest workers in the United States

This study examines regional differences in the legal status of forest workers in the Pacific Northwest and Southeastern United States, using United States Department of Labor data and qualitative fieldwork in Alabama and Oregon. The authors find that there are significantly fewer H-2B guest workers on federal lands in Oregon than on privately owned forest plantations in Alabama, and the Southeast more generally. By contrast, numerous workers on federal lands in Oregon are undocumented. This difference may largely be explained by variations in the economies of scale in forest work in the Pacific Northwest (federal lands) and the Southeast (mainly private lands). The study also finds that there is no real difference in the working conditions of undocumented immigrants and guest workers—both groups face labor exploitation. Guest workers in the forest industry, many of whom have no previous work experience or access to social networks in the United States, face extreme isolation at worksites, are beholden to contractors, fear losing their jobs if they complain, and are generally unaware of their basic rights. By contrast, many undocumented forest workers in Oregon belong to established social networks through which they are recruited onto forest labor crews. However, unauthorized workers are also vulnerable to labor exploitation because they fear deportation and are obliged to their kin-employers. Policy recommendations to improve labor conditions and enforce existing labor laws for all forest workers include: better tracking of workers across states to monitor labor abuses, allocating more resources to state labor departments to facilitate worker outreach and worksite inspections, and better communication among land management officials and the Department of Labor.
Changes in the respiratory cycle associated with sleep.

Abstract The respiratory cycle of unmedicated, unrestrained cats was compared in 3 conditions: awake, slow-wave sleep (SWS) and rapid eye movement sleep (REMS). Average inspiratory and expiratory flow rates were similar in the three. Tidal volume and the durations of both respiratory phases increased approximately 30% during SWS and returned to the awake range during REMS. These shifts can be attributed to changes in the timing of the termination of inspiration; sleep exerted no effect on the rate of rise of diaphragmatic EMG. The sleep-associated shifts do not manifest alterations in a vagal reflex since they persisted following chronic bilateral vagotomy. Vagotomized animals showed increased variation in the respiratory cycle during REMS, however. The results suggest that SWS resets a central mechanism influencing termination of inspiration and that this action is offset or eliminated during REMS. The constancy of diaphragmatic activation and end-tidal P CO 2 suggests that other features of respiratory control are not greatly altered during sleep.
The Effects of Subcloud-Layer Diabatic Processes on Cold Air Damming

Abstract The hypothesis that clouds and precipitation enhance cold air damming is examined. A case example of cloud/precipitation-induced enhancement of damming is presented and a conceptual model is proposed. It is found that the subcloud-layer diabatic effects associated with areas of precipitation produce mesoscale changes in pressure, wind, and static stability. These changes tend to maintain or strengthen damming in two fundamental ways: 1) Cloud cover maintains damming by preventing or reducing the radiative destabilization in the upslope layer. Without cloud cover, the lapse rate is more likely to increase so that upslope adiabatic cooling, and therefore the potential for damming, is decreased. 2) Subcloud-layer diabatic cooling from evaporation and reduced radiation produces a hydrostatic pressure rise in the precipitation zone. The low-level wind field adjusts to the pressure rise in such a manner that it enhances advection of low-level cold air southward under progressively warmer air just above...
Nietzsche's Naturalized Aestheticism

This essay seeks to overcome the divide that has emerged in recent scholarship between Alexander Nehamas’s reading of Nietzsche as an aestheticist who eschews the dogmatism implicit in the scientific project and Brian Leiter's reading of Nietzsche as a hard-nosed naturalist whose project is continuous with the natural sciences. It is argued that Nietzsche turns to the natural sciences to justify a relationalist ontology that not only eliminates metaphysical concepts such as ‘being’ and ‘things-in-themselves’, but also can be linked to key components of the aestheticist reading. As a result, Nietzsche's naturalism should not be understood as opposing important features of his aestheticism. Instead, Nietzsche's project should be understood in terms of a naturalized aestheticism that rejects the metaphysical-moral interpretation of existence espoused by philosophers such as Plato, Kant, and Schopenhauer.
ELECTRON MICROSCOPE STUDIES ON THE CELLS OF THE MALPIGHIAN TUBULES OF THE GRASSHOPPER (ORTHOPTERA, ACRIDIDAE)*

For purposes of description, the cells of the Malpighian tubules of the grasshopper may be divided into basal, intermediate, and apical zones. The basal zone of the cell contains what appears to be an elaborate infolding of the cell membrane at the base. This condition results in the basal cell cytoplasm being divided into many compartments. The compartments contain mitochondria that are often arranged in rows. Other small bodies which possess relatively dense outer borders and less dense cores were observed within the compartments. These bodies are unidentified. The brush border of the apical zone contains a multitude of vertically arranged protoplasmic processes. Stages were found which suggest that the filamentous mitochondria migrate from the cell body to the base of the protoplasmic processes, where they enter them and move apically. Some of the mitochondria were observed at the very tips of the processes where they enlarge producing an accompanying bulging of the tips. This condition is interpreted as a stage in the pinching off of the mitochondria-laden tips of the protoplasmic processes.
Separated-spacecraft interferometer concept for the New Millennium Program

A separated spacecraft optical interferometer mission concept proposed for NASA's New Millennium Program is described. The interferometer instrument is distributed over three small spacecraft: two spacecraft serve as collectors, directing starlight toward a third spacecraft which combines the light and performs the interferometric detection. As the primary objective is technology demonstration, the optics are modest size, with a 12-cm aperture. The interferometer baseline is variable from 100 m to 1 km, providing angular resolutions from 1 to 0.1 milliarcseconds. Laser metrology is used to measure relative motions of the three spacecraft. High-bandwidth corrections for stationkeeping errors are accomplished by feedforward to an optical delay line in the combiner spacecraft; low-bandwidth corrections are accomplished by spacecraft control with an electric propulsion or cold-gas system. Determination of rotation of the constellation as a whole uses a Kilometric Optical Gyro, which employs counter-propagating laser beams among the three spacecraft to measure rotation with high accuracy. The mission is deployed in a low-disturbance solar orbit to minimize the stationkeeping burden. As it is well beyond the coverage of the GPS constellation, deployment and coarse stationkeeping are monitored with a GPS-like system, with each spacecraft providing both transmit and receive ranging and attitude functions.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Scalable and Practical Pursuit-Evasion with Networked Robots

In this paper, we consider the design and implementation of practical pursuit-evasion games with networked robots, where a communication network provides sensing-at-a-distance as well as a communication backbone that enables tighter coordination between pursuers. We first develop, using the theory of zero-sum games, an algorithm that computes the minimal completion time strategy for pursuit-evasion when pursuers and evaders have same speed, and when all players make optimal decisions based on complete knowledge. Then, we extend this algorithm to when evader are significantly faster than pursuers. Unfortunately, these algorithms do not scale beyond a small number of robots. To overcome this problem, we design and implement a partition algorithm where pursuers capture evaders by decomposing the game into multiple multi-pursuer single-evader games. We show that the partition algorithm terminates, has bounded capture time, is robust, and is scalable in the number of robots. We then describe the design of a real-world mobile robot-based pursuit evasion game. We validate our algorithms by experiments in a moderate-scale testbed in a challenging office environment. Overall, our work illustrates an innovative interplay between robotics and communication.
PCCA: a program for phylogenetic canonical correlation analysis.

Summary: PCCA (phylogenetic canonical correlation analysis) is a new program for canonical correlation analysis of multivariate, continuously valued data from biological species. Canonical correlation analysis is a technique in which derived variables are obtained from two sets of original variables whereby the correlations between corresponding derived variables are maximized. It is a very useful multivariate statistical method for the calculation and analysis of correlations between character sets. The program controls for species non-independence due to phylogenetic history and computes canonical coefficients, correlations and scores; and conducts hypothesis tests on the canonical correlations. It can also compute a multivariate version of Pagel’s , which can then be used in the phylogenetic transformation. Availability: PCCA is distributed as DOS/Windows, Mac OS X and Linux/Unix executables with a detailed program manual and is freely available on the World Wide Web at: http://anolis.oeb.harvard.edu/� liam/programs/.
Creutzfeldt-Jakob Disease and eating squirrel brains

Of the 3418 children in the cohort, 183 (5·4%) had no weights recorded; 3028 (89%) had a birth-weight, and 3161 (92·5%) at least one clinic weight. Only 1075 (31%) had weights in each of the six target age bands but 3002 (88%) children had weights in at least two. 2823 (83%) of the cohort were represented at 6 weeks, falling to 1724 (50%) by 18 months. 2730 (80%) children had an adequate clinical record, with negligible variation by the level of deprivation (no [%] adequate: affluent 291 [76·8]; intermediate 1898 [80·6]; deprived 526 [76·9]). The 703 (21%) of children with inadequate records consisted of 257 (7·5%) with no clinic weights and 446 (13%) with weights in only the first or second half of the first year. Health visitors suggested that this was because of lost records in 288 (41%) and poor attendance in 51 (7%), but in half no explanation was given. A striking finding was that those children with most weights were consistently lighter, while children with inadequate records, when weighed, were heaviest (table). It was reassuring that those children most often brought for weighing were those most in need of monitoring. However, this introduces the possibility of bias where weight data are used at a population level, because the more weights a child has, the less representative of the cohort the child will be. Thus where longitudinal growth data are used, the minimum number of weights available for the maximum number of children should ideally be used: in our dataset using six weights per child meant only a third of the cohort were represented, while using just two would include up to 88%.
Reovirus Core Protein μ2 Determines the Filamentous Morphology of Viral Inclusion Bodies by Interacting with and Stabilizing Microtubules

Cells infected with mammalian reoviruses often contain large perinuclear inclusion bodies, or "factories," where viral replication and assembly are thought to occur. Here, we report a viral strain difference in the morphology of these inclusions: filamentous inclusions formed in cells infected with reovirus type 1 Lang (T1L), whereas globular inclusions formed in cells infected with our laboratory's isolate of reovirus type 3 Dearing (T3D). Examination by immunofluorescence microscopy revealed the filamentous inclusions to be colinear with microtubules (MTs). The filamentous distribution was dependent on an intact MT network, as depolymerization of MTs early after infection caused globular inclusions to form. The inclusion phenotypes of T1L x T3D reassortant viruses identified the viral M1 genome segment as the primary genetic determinant of the strain difference in inclusion morphology. Filamentous inclusions were seen with 21 of 22 other reovirus strains, including an isolate of T3D obtained from another laboratory. When the mu2 proteins derived from T1L and the other laboratory's T3D isolate were expressed after transfection of their cloned M1 genes, they associated with filamentous structures that colocalized with MTs, whereas the mu2 protein derived from our laboratory's T3D isolate did not. MTs were stabilized in cells infected with the viruses that induced filamentous inclusions and after transfection with the M1 genes derived from those viruses. Evidence for MT stabilization included bundling and hyperacetylation of alpha-tubulin, changes characteristically seen when MT-associated proteins (MAPs) are overexpressed. Sequencing of the M1 segments from the different T1L and T3D isolates revealed that a single-amino-acid difference at position 208 correlated with the inclusion morphology. Two mutant forms of mu2 with the changes Pro-208 to Ser in a background of T1L mu2 and Ser-208 to Pro in a background of T3D mu2 had MT association phenotypes opposite to those of the respective wild-type proteins. We conclude that the mu2 protein of most reovirus strains is a viral MAP and that it plays a key role in the formation and structural organization of reovirus inclusion bodies.
In situ monitoring and control for MBE growth of optoelectronic devices

Improved control over layer thickness has been realized using optical interference techniques such as reflectance spectroscopy. It is now common to observe spectra of distributed-Bragg-reflector (DBR) mirrors during growth to make corrections for growth rate drifts. Real-time optical flux monitoring (OFM) by atomic absorption allows precise layer control by measuring group III fluxes continuously during growth. The flux information can be used to operate growth shutters and to control effusion cell heaters in a feedback loop. Improved substrate temperature measurement by diffuse reflectance spectroscopy (DRS) allows precise measurement of substrate temperature. DRS is not subject to the same errors encountered in pyrometer or thermocouple measurements of substrate temperature.
Cortical Operation of the Ventral Striatal Switchboard

How does the ventral striatum (VS) prioritize and process afferent input? In this issue, Calhoon and O'Donnell (2013) demonstrate that cortical projections to the VS can attenuate hippocampal and thalamic VS input, suggesting that the cortex can uniquely control VS circuit dynamics.
FOSSIL MUSHROOMS FROM MIOCENE AND CRETACEOUS AMBERS AND THE EVOLUTION OF HOMOBASIDIOMYCETES

Two species of fossil mushrooms that are similar to extant Tricholomataceae are described from Cretaceous and Miocene ambers. Archaeomarasmius leggetti gen. et sp. nov., from mid-Cretaceous amber of New Jersey, resembles the extant genera Marasmius and Marasmiellus. Two fruiting bodies of Archaeomarasmius were found. One consists of a complete pileus with stipe, and the other consists of a fragment of a pileus. The latter was accidentally exposed, and zxsubsequently was used for molecular systematics studies (attempts to amplify ribosomal DNA were unsuccessful) and electron microscopy. The spores are smooth and broadly elliptic with a distinct hilar appendage. Protomycena electra gen. et sp. nov., which is represented by a single complete fruiting body from Miocene amber of the Dominican Republic, is similar to the extant genus Mycena. Based on comparison to extant Marasmieae and Myceneae, Archaeomarasmius and Protomycena were probably saprophytes of leaf litter or wood debris. The poor phylogenetic resolution for extant homobasidiomycetes limits the inferences about divergence times of homobasidiomycete clades that can be drawn from Archaeomarasmius and Protomycena. The ages of these fossils lend support to hypotheses that the cosmopolitan distributions of certain mushroom taxa could be due to fragmentation of ancestral ranges via continental drift. Anatomical and molecular studies have suggested that there has been extensive convergence and parallelism in the evolution of homobasidiomycete fruiting body form. Nevertheless, the striking similarity of these fossils to extant forms suggests that in certain lineages homobasidiomycete macroevolution has also involved long periods during which there has been little morphological change.