cssi/SciSciGPT-SciSciNet huggingface dataset:
Sudden Shift or Migratory Drift? FulBe Herd Movements to the Sudano-Guinean Region of West Africa

A significant change in the geography of livestock raising over the past 30 years is the southerly movement of FulBe herds into the humid Sudanian and Guinean savannas of West Africa. The literature suggests that the severe droughts of the early 1970s and mid-1980s were the driving force behind this southern expansion of mobile livestock raising. The conventional view is that drought forced herders to seek greener pastures to the south, an area that zebu cattle have previously avoided because of the presence of tsetse flies, the vector of animal sleeping sickness (trypanosomiasis). This “sudden push” hypothesis places Sahelian herds in savanna pastures in a matter of a 1–3 years. This stimulus-response model runs counter to our observations and understanding of the social and ecological processes influencing FulBe herd movements. We challenge the “sudden shift” thesis at the regional scale by arguing that the southerly expansion of FulBe herds has proceeded according to a more complex temporal frame that includes generational, biological, and social historical timeframes and periodicities. We distinguish between short-term shifts (“test movements”) and more permanent shifts (“migration movements”). These mobility patterns are linked to contingent factors such as cattle diseases, drought, and political instability, as well as to more structural and adaptive features such as the establishment of social networks, herding contracts, and cattle cross-breeding. Shifts in livestock ownership and the social differentiation among herders are important variables for understanding changes in herd movements. We conclude that the permanent shift of herds to the humid savannas of West Africa has been preceded by a series of social and agroecological adjustments that operate on decadal and generational time scales.
The Use of Saccharomyces cerevisiae to Suppress the Effects of Aflatoxicosis in Broiler Chicks

Three hundred and sixty day-old commercial broiler chicks were assigned to a 3 x 2 factorial arrangement of treatments to examine the effects of three levels of Saccharomyces cerevisiae 0, .05, and .1% of feed, and two levels of aflatoxin, 0 and 5 ppm, singly and in combination on aflatoxicosis. Each treatment group was replicated three times. The S. cerevisiae and aflatoxin were incorporated in a standard commercial broiler ration and fed to chicks for 4 wk. Data were collected weekly on body weights, and at the end of the experiment on the relative weights of the liver, proventriculus, pancreas, and heart. Serum concentrations of the albumin, total protein, cholesterol, uric acid, triglycerides, and enzyme activities of alanine transaminase, aspartate aminotransferase, lactase dehydrogenase, and creatine phosphokinase were also evaluated. Results showed that chicks receiving aflatoxin-contaminated feed had suppressed body weight (456 g), which significantly improved (516 g) with the inclusion of .1% S. cerevisiae. The relative weights of liver (3.58%), heart (.916%), and proventriculus (.770%), which increased significantly with the addition of 5 ppm of aflatoxin, were restored to 3.00, .783, and .680%, respectively, with the dietary inclusion of .1% S. cerevisiae. The serum concentrations of albumin and total protein (.66 and 1.62 g/100 mL), which were significantly decreased by aflatoxin, were elevated to .88 and 2.24 g/100 mL, respectively, with the inclusion of .1% S. cerevisiae.(ABSTRACT TRUNCATED AT 250 WORDS)
Emil du Bois-Reymond vs Ludimar Hermann.

Abstract This essay recounts a controversy between a pioneer electrophysiologist, Emil du Bois-Reymond (1818–1896), and his student, Ludimar Hermann (1838–1914). Du Bois-Reymond proposed a molecular explanation for the slight electrical currents that he detected in frog muscles and nerves. Hermann argued that du Bois-Reymond's ‘resting currents’ were an artifact of injury to living tissue. He contested du Bois-Reymond's molecular model, explaining his teacher's observations as electricity produced by chemical decomposition. History has painted Hermann as the wrong party in this dispute. I seek to set the record straight. To cite this article: G. Finkelstein, C. R. Biologies 329 (2006).
Genetic alterations in the phosphoinositide 3-kinase/Akt signaling pathway confer sensitivity of thyroid cancer cells to therapeutic targeting of Akt and mammalian target of rapamycin.

We investigated the genotype-dependent therapeutic potential of targeting the PI3K/Akt pathway for thyroid cancer. Proliferation of TPC1, Hth7, FTC133, OCUT1, K1, and BCPAP cells that harbored PI3K/Akt-activating genetic alterations was potently inhibited by the Akt inhibitor perifosine whereas SW1736, Hth74, WRO, KAT18, and TAD2 cells that harbored no genetic alterations had no or only modest responses. Inhibition of Akt phosphorylation by perifosine was seen in these cells. Genetic-dependent apoptosis was induced by perifosine in cells selectively tested. Similarly, potent inhibition of cell proliferation by the mTOR inhibitor temsirolimus occurred in virtually all the cells harboring genetic alterations whereas modest inhibition was seen in some of the cells not harboring genetic alterations. Temsirolimus inhibited the phosphorylation of p70S6K, a substrate of mTOR. Knockdown of Akt1/2 or mTOR by shRNA approach inhibited the proliferation and colony formation of FTC133 and OCUT1 cells that harbored genetic alterations in the PI3K/Akt pathway but had no effect on SW1736 and KAT18 cells that did not. Transfection with PIK3CA mutants greatly sensitized SW1736 cells to perifosine and temsirolimus. Growth of xenograft tumors derived from FTC133 cells but not SW1736 cells in nude mice was dramatically inhibited by perifosine. Thus, this work for the first time demonstrates that genetic alterations in the PI3K/Akt pathway confer thyroid cancer cells addiction to this pathway and their sensitivity to inhibition by targeting Akt and mTOR. This genotype-based targeting of the PI3K/Akt pathway using Akt and mTOR inhibitors may offer an effective therapeutic strategy for thyroid cancer and warrants further studies.
Concentration and Fractionation of Skimmilk by Reverse Osmosis and Ultrafiltration

Abstract The influence of process operating parameters on the performance of reverse osmosis and ultrafiltration modules during concentration and fractionation of skimmilk has been investigated. The effects of temperature, pressure, feed flow rate, and feed composition on the permeate flux are reported. The transmembrane flux at a fixed operating pressure and temperature is governed by a resistance term which results from the contributions of three factors: Resistance of the membrane proper. Resistance of a proteinaceous deposit or gel (largely casein) which is deposited on the membrane surface during ultrafiltration or reverse osmosis. Resistance arising from concentration polarization effects in the boundary layer at the fluid interface. Reverse osmosis may be used to produce concentrated skimmilks from which over 60% of the water has been removed. Ultrafiltration may be used to produce protein enriched skimmilk concentrates. Potential uses of these products are discussed.
Lead and nickel alter the cardiorenal actions of endothelin in the rat.

In the current study, we have determined to what extent lead and nickel alter the cardiorenal actions of endothelin in pentobarbital anesthetized female rates. One hour following surgery, 3 x 15-min renal clearances were collected and endothelin (ET)-1 was infused iv at 100 ng/kg/min for 30 min during which time an additional two clearances was collected. Lead (infused as lead acetate throughout the experiment) at 4.8 nmoles/min and 24 nmoles/min significantly attenuated the ET-induced increase in mean arterial pressure (MAP); lead infused at 0.48 nmoles/min had no effect. An ET-induced decrease in the glomerular filtration rate (GFR) in control rats was completely blocked by the higher doses of Pb{sup 2+}. By contrast, Pb{sup 2+} had no effect on angiotensin II or norepinephrine induced increases in MAP. In additional experiments, calcium chloride was infused at 500 nmoles/min for 105 min, then Ca{sup 2+} + Pb{sup 2+} (4.8 nmoles/min) were infused for another 105 min; in these experiments, there was no Pb{sup 2+}-induced inhibition of the MAP response to endothelin: the GFR response to the peptide remained blocked. NiCl{sub 2} reduced the ET-induced increase in MAP only at 24 nmoles/min; at 4.8 and 24 nmoles/min, nickel attentuated the decrease in GFR inducedmore » by ET. Finally, Ca{sup 2+} infusion had no effect on the inhibition by Ni{sup 2+} of the GFR response to ET. These data illustrate that (i) lead inhibits the cardiorenal actions of endothelin; (ii) a Ca{sup 2+}-related process is involved the systemic but not the renal component of this inhibition; (iii) since the heavy metal does not affect angiotensin II or nonrepinephrine-induced increases in MAP, the inhibition by lead of the systemic response is relatively specific for endothelin; and (iv) nickel also inhibits the renal response to the peptide but higher doses are required to inhibit the systemic response. 35 refs., 4 figs., 2 tabs.« less
Behavioral plasticity of the soft-shell clam, Mya arenaria (L.), in the presence of predators increases survival in the field

Soft-shell clams, Mya arenaria, are sessile, suspension-feeding bivalves that are preyed upon by the exotic green crab, Carcinus maenas. Clams evade crab consumers by burrowing deeper into the sediment after perceiving a threat from a nearby predator. The purpose of this study was to determine the types of signals that M. arenaria use to detect predators and the types of behaviors clams use to avoid being eaten. In a field study, clams increased their burial depth in the presence of green crab predators consuming conspecifics that were caged nearby, and also increased burial depth after artificial tactile stimulation in the laboratory assay. These results indicate that clams can use chemical and mechanical cues to detect potential predatory threats. We performed a field study to examine the difference in survivability of clams that had burrowed deeper into the sediment in response to predators vs. control clams that were burrowed less deeply. Significantly higher survival rates were observed in clams that had initially burrowed more deeply, suggesting that increasing burial depth is a valid predator avoidance strategy. Some bivalves also alter their pumping rates in the presence of predators, making them less apparent and providing more structural defense by covering soft tissue, and we measured pumping time of soft-shell clams in the presence and absence of predators, when burrowing was not an option for escape. Soft-shell clams did not alter their pumping time in the presence of green crab predators, possibly because they employ a burrowing method called “hydraulic” or “jet-propelled” burrowing, where it is necessary for the clam to pump in order to burrow. Chemical signals and tactile cues instigated behavioral changes in M. arenaria, and this change in behavior (increasing burial depth) increased clam survival in the field.
Special issue on PODC 2009

This special issue of Distributed Computing is based on four papers that originally appeared, in preliminary and abbreviated form, in the Proceedings of the 28th ACM Symposium on the Principles of Distributed Computing (PODC 2009), held in Calgary, Canada, on August 10–12. The papers were chosen by the Program Committee from the 27 full-length papers presented at the Symposium and are fine examples of the quality and diversity of the research presented at PODC. In the first paper, Randomized Mutual Exclusion with Sub-Logarithmic RMR-Complexity, Hendler and Woelfel shed new light on the fundamental mutual exclusion problem, showing that randomized mutual exclusion algorithms that use only reads and writes can overcome the logarithmic lower bound shownbyAttiya,Hendler, andWoelfel for deterministic algorithms, and achieve sub-logarithmic complexity when measured in terms of remote memory references (RMRs). The second paper, Load Balancing Without Regret in the Bulletin Board Model presents an excellent example of the growing interest of the PODC community in algorithmic game theory. Kleinberg, Piliouras, and Tardos study the performance of a simple, well-known, no-regret multiplicativeweights algorithm for a class of load balancing games in a model where players can query the current state of the system but cannot reliably predict the effect of their actions on it. Using non-standard analysis, they show that the makespan (i.e. the maximum load over all machines) achieved by this simple algorithm deviates in any step by at most O(log n) from the optimal makespan, a result that is exponentially
Radiochemically ultrapure 14CO

Abstract Preparation of ultra high-purity 14CO tracers by the reduction of 14CO2 by Zn at 395°C are described. Purity levels of 10 −8 14 CO 2 14 CO have been obtained by successive freeze-outs of 12CO2 carrier gas at liquid-nitrogen temperature. Radiochemical purity of the 14CO is limited by radiolysis and surface catalysis. The radiolysis rate of 14CO corresponds to a G(CO2) of 2.5 ± 0.9. Techniques are discussed to reduce these problems.
Immunologic response and pathogenesis of Japanese B infection in peripherally inoculated normal and cortisone treated hamsters.

SummaryMost hamsters are not susceptible to disease following subcutaneous inoculation of JBE virus, probably due to early production of antibodies. Normal hamsters when inoculated with JBE virus subcutaneously, developed viremia 6 hours after inoculation. This viremia reached its maximum after 24 hours and disappeared by the 4th day. Virus appeared in the brain on the 4th day and reached its maximum around the 7th or 8th day and disappeared after the 10th or 12th day. Neutralizing antibodies to JBE virus were detected in their sera beginning on the 4th or 5th day and reached their maximum titer around the 27th or 34th day after inoculation. In cortisone treated hamsters viremia reached its maximum by the 3rd day and disappeared after the 4th day. Virus was detected in the brains of these hamsters from the 3rd day after inoculation, reached its maximum on the 7th or 8th day and remained at a high level to the end of the experiment. Neutralizing antibodies to JBE virus attained a significant level (1.7 log...
Pheromone trap for monitoring insecticide resistance in the pink bollworm moth (Lepidoptera: Gelechiidae): new tool for resistance management

A rapid technique using sex pheromone and insecticide-laced traps was developed for measuring insecticide resistance in pink bollworm moth, Pectinophora gossypiella (Saunders). This method was developed in the laboratory by allowing males to fly upwind to a sex-pheromone source in a wind tunnel, and then trapping them on sticky cards (laced with various doses of pyrethroid insecticides) inserted into standard delta traps. Using this technique, populations of adult male P. gossypiella trapped in the field were shown to be more resistant to permethrin and fenvalerate in fields frequently treated with pyrethroids than in fields with little or no exposure to these insecticides. The new method eliminates handling of insects that is involved in other methods of assessing toxicity, and is compatible with the current practice of monitoring populations with pheromone traps. It was important to test and standardize duration of males' postcapture exposure to insecticide-laced sticker, temperature that males were exposed to after capture, quantity of sticker used, and age of males when captured.
Neuron survival in the aging mouse.

Abstract A cell suspension of the entire mouse brain can be made by sonication after formalin fixation. By counting the number of cells in a measured volume of the suspension, the cell population of the whole brain can be determined. The young mouse brain contains about 5 1 2 million neurons. In extreme old age this number decreases to about 2 million. The loss of neurons does not proceed at a constant rate but accelerates throughout the life of the animal, following a Gompertz function. A comparison of Gompertz curves shows that the mouse and his neurons age at about the same rate.
An Examination of the Influence of Theory and Individual Theorists on Empirical Research in Microeconomics

Most economists would concur that an important role of economic theory is to influence the direction of empirical research, either by posing new questions or by suggesting new answers to old questions. Whether or not modem theory should be judged to be a success on that metric is a frequently debated question, but one on which there has been little systematic investigation. In this paper, we provide some preliminary empirical evidence on the extent to which various fields of economic theory, as well as specific theorists, have succeeded in influencing the path followed by empirical research in the area of microeconomics. Based on our analysis of all empirical microeconomics papers published in three leading journals over a three-year period, we arrive at a number of conclusions concerning the impact of theory on empirical research. Our first finding is that the set of theory papers cited as the primary motivation for leading empirical work is surprisingly dispersed. Very few individual works of theory seem to have exerted a great influence. In the 149 empirical papers we consider, one author (Gary Becker) is cited 15 times, but no other author is cited more than 10 times; no single paper is cited more than five times. A second finding is that empirical researchers behave as if they are heavily influenced by recent theoretical contributions. Among the theory pa
Patterns and trends in the fields of bioturbation, faunalturbation, and zoogeomorphology

This paper examines published works in the related fields of zoogeomorphology, bio(pedo)turbation, and faunal(pedo)turbation. Using Google Scholar, we extracted widely cited works for each of these three terms and their derivations (e.g. bioturbation, biopedoturbation, biopedturbation). For each term, we graphed the number of publications per year, most published authors, and research topics. Our graph of publications per year revealed that while publications on bio(pedo)turbation and faunal(pedo)turbation have decreased, publications on zoogeomorphology have steadily increased since its introduction in 1992. Author analysis found that the majority of authors are actively publishing in only one of the three fields; only 25 of the 627 authors in our sample published in multiple fields. Additionally, we found that works for each individual topic illustrated somewhat different research emphases than those of the other two. Published works in zoogeomorphology focus on riparian environments, mountain environme...
CONSTRAINTS, HERMITICITY, AND CORRESPONDENCE

In order to expose the essential features of the quantization of a theory with constraints, we consider the most elementary system, that of a free particle. We show that even for this simple system, when expressed in a constraint formalism, it requires the introduction of an indefinite metric in the Hilbert space, non-Hermitian constraints, and indeed most other features which we have come to associate with the Gupta-Bleuler formalism of electrodynamics. By introducing a conceptually new object, the quasiobservable, we show how an Ehrenfest correspondence principle may be obtained for the resulting quantum theory.
Outcomes of Robot-Assisted Pancreaticoduodenectomy in Patients Older Than 70 Years: A Comparative Study

Minimally invasive pancreaticoduodenectomy (PD) remains one of the most challenging abdominal procedures and its application in the elderly population is poorly reported in the literature so far. The goal of this study was to demonstrate that robot-assisted PD can be safely performed in patients aged 70 years and older. Forty-one consecutive robot-assisted PD performed between April 2007 and January 2010 were prospectively entered in a dedicated database. Patients were stratified into two groups: group 1, aged ≥70 years (n = 15, 36.6%); and group 2, aged <70 years (n = 26, 63.4%). The data were reviewed retrospectively. Indications for surgery and patient characteristics were the same in both groups, with the exception of age. There was no statistical difference in terms of operative time (P = 0.376), blood loss (P = 0.989), conversion rate (P = 0.52), mortality (P = 0.36), or overall morbidity rate (P = 0.74). The mean hospital stay was 14.3 days in group 1 and 11.2 days in group 2. This was not statistically significant (P = 0.136). Robot-assisted pancreaticoduodenectomy can be performed safely in elderly patients with comparable mortality, morbidity, and outcomes compared with a younger population. Age alone should not be a contraindication for robotic pancreatic resection.
Pressure-composition phase diagram for hydrides of rare earth-Fe2 laves compounds

Abstract The pressure-composition-temperature phase diagram for the absorption of hydrogen in the cubic Laves phase compound ErFe2 has been investigated. At least three stable hydrides ErFe2Hn are found with n ≈ 2, 3.4 and 4. At 20 °C, the equilibrium pressures for these phases are 0.04, 10 and 4000 Torr, respectively. The implications of these results on the preparation of samples for the measurement of physical properties is discussed.
Two-phase equilibrium model of insulator–insulator contact charging with electrostatic potential

Abstract A two-phase equilibrium model based on an ideal gas of singly charged ions in equilibrium with a submonolayer adsorbed film was developed to describe the pressure dependence of insulator–insulator contact charging. Experimental data show that the surface charge density decreases with respect to pressure for insulators as pressure is lowered. In this work, the gas phase of the two-phase model is extended to consider the electrostatic coulombic and screening potentials from the surface.
HLA-A2.1-associated peptides from a mutant cell line: a second pathway of antigen presentation.

Peptides extracted from HLA-A2.1 class I major histocompatibility complex (MHC) molecules expressed on the antigen processing mutant CEMx721.174.T2 were characterized by electrospray ionization-tandem mass spectrometry. Only seven dominant peptides were found, in contrast to over 200 associated with HLA-A2.1 on normal cells. These peptides were derived from the signal peptide domains of normal cellular proteins, were usually larger than nine residues, and were also associated with HLA-A2.1 in normal cells. These results suggest that proteolysis of signal peptide domains in the endoplasmic reticulum is a second mechanism for processing and presentation of peptides for association with class I molecules.
A Model for Epithelial Migration and Wound Healing in the Avian Embryo

It is increasingly clear that (collective) migration of epithelia plays an important role in morphogenesis and wound healing [6]. One of the interesting phenomena about epithelial migration is that the leading edge of the epithelia displays characteristics of both epithelia and cells undergoing EMT (epithelial-to-mesenchymal transition), so-called “partial” EMT. Developmental models in Drosophila and zebrafish have become important for studying signaling pathways involved in epithelial migration in recent years, but it is difficult to study the biomechanics of these systems. [2] Here, we revisit a little-used developmental model originally characterized by Chernoff [3] over two decades ago, which uses the area opaca (AO) of the chick embryo, an extraembryonic epithelium in birds which normally functions to spread across and encompass the nutritive yolk in a process called epiboly. We believe this model will be useful for studying epithelial migration because it is easily accessible and can be separated from the embryo to control the biomechanical environment.Copyright © 2010 by ASME
Frequency domain solutions to multi-degree-of-freedom, dry friction damped systems

Dry friction damping has been considered as a means of increasing the passive damping of a variety of systems including large space structures and turbomachinery blades. However, dry friction is highly nonlinear, and hence, analytical investigations are difficult to perform. Here, a multiharmonic, frequency domain solution technique is developed and applied to a multi-degree-of-freedom, dry friction damped system. It is seen that the multiharmonic method is more accurate than traditional, one-harmonic solution methods. The method also compares favorably with time integration. Finally, comparisons are made with experimental results.
Non-closure of the image model and absence of fixed points

On considere des proprietes des plongements elementaires et leurs relations aux hypotheses de grand cardinal dans ZFC
Bronchoscopic management of central airway obstruction.

Abstract Objectives: Patients with central airway obstruction are critically ill, with impending suffocation. They are seen with diverse anatomic and functional deficits caused by both benign and malignant obstructions. Such cases were reviewed to examine the indications, techniques, and outcomes of an algorithm approach to bronchoscopic management. Methods: Between July 1992 and April 1996, 97 patients underwent bronchoscopic procedures for the management of central airway obstruction, and their cases were used for a retrospective review of the airway management. Results: There were 48 male and 49 female patients, aged 13 to 85 years. There were 48 benign and 49 malignant pathologic conditions that gave rise to 108 stenoses. These were treated with 199 endoscopic procedures with an average of 1.7 interventions per endoscopy, including mechanical core-out (62), dilation (135), laser ablation (44), placement of brachytherapy catheters (9), and stent placement (88). Diagnoses included lung cancer, primary tracheobronchial tumors, tumors metastatic to the airway or mediastinum, and a variety of benign obstructions. In the group of 97 patients there were 2 (2%) perioperative deaths and 34 (34%) late deaths, 29 in the malignant group and 5 in the benign group. Median survival was 7.6 months (range 1 week–31 months). There were 7 (7%) complications among the group of 97, 4 in the malignant group, and 3 in the benign group. Conclusions: Endobronchial surgical techniques can be used safely and systematically for the relief of benign and malignant central airway obstructions; a diversity of approaches and interventions are required to produce and maintain palliation of airway symptoms. (J Thorac Cardiovasc Surg 2000; 119:289-96)
Thailand’s Agrarian Myth and Its Proponents

Thailand’s agrarian myth holds that culturally-based, small-scale subsistence farming is the most desirable form of community life for rural Thais. This article outlines Thailand’s agrarian myth and argues that its current promotion finds support in an obsolete ‘sufficiency ethic’, rather than from the country’s pragmatically-oriented farmers. Proponents of this myth come from Thailand’s cultural and bureaucratic elite, urban intellectuals, and religious fundamentalists. Based on field research and secondary sources the article demonstrates how the attitudes and behaviors of contemporary Thai farmers belie the agrarian myth which non-farming elites now advocate. The article concludes that yellow-shirted proponents of Sufficiency Economy, Community Culture, and austere Buddhist fundamentalism should adjust their vision to the reality that Thailand’s forward-looking farmers desire a rural lifestyle beyond the agrarian myth.
LAW AND SOCIAL THEORY IN THE TWENTY‐FIRST CENTURY

The time has come, indeed, it is long past due, to recognize that economic and political institutions honored by time but by little else must be altered, and substantially so, if Western industrialized nations are to come through the stormy seas that lie dead ahead and move on to the high ground of a safer and saner planet. Moreover, those institutions will be altered, by the force of circumstance; and the question thus becomes whether change can be guided and, if so, can help resolve the problems pertaining to a dramatic change in humankind's relation to the environment.
The Contemporary President: Should the Senate Take a Floor Vote on a Presidential Judicial Nominee?

President George W. Bush has argued that the Senate ought to hold final up-or-down floor votes on all of his judicial nominations rather than use various parliamentary procedures to prevent such action. Some scholars argue that there is no traditional mandate for such a demand, and that the Senate is well within its prerogatives to deny the president's request. This article revisits the question of Senate parliamentary procedures and the president's function to nominate individuals to the judicial branch. The article examines Founding-era debates to determine whether current practice comports with the logic and design of the system. By focusing on similar constitutional procedures from a separation-of-powers perspective, the article argues that filibusters of judicial nominations are not well founded in constitutional logic. The article concludes by evaluating whether such a change would lead to excessive presidential influence in staffing the judiciary.
Recycling of butanol from irradiated target material

Abstract The polarization of polarized proton targets made with ordinary butanol distilled from previously irradiated target material has been found to equal that of unused material.
Regulation of Abscisic Acid-Induced Stomatal Closure and Anion Channels by Guard Cell AAPK Kinase

Abscisic acid (ABA) stimulates stomatal closure and thus supports water conservation by plants during drought. Mass spectrometry-generated peptide sequence information was used to clone a Vicia faba complementary DNA, AAPK, encoding a guard cell-specific ABA-activated serine-threonine protein kinase (AAPK). Expression in transformed guard cells of AAPK altered by one amino acid (lysine 43 to alanine 43) renders stomata insensitive to ABA-induced closure by eliminating ABA activation of plasma membrane anion channels. This information should allow cell-specific, targeted biotechnological manipulation of crop water status.
Declarative platform for high-performance network traffic analytics

This paper presents Scalanytics, a declarative platform that supports high-performance application layer analysis of network traffic. Scalanytics uses (1) stateful network packet processing techniques for extracting application layer data from network packets, (2) a declarative rule-based language called Analog for compactly specifying analysis pipelines from reusable modules, and (3) a task-stealing architecture for processing network packets at high throughput within these pipelines, by leveraging multi-core processing capabilities in a load-balanced manner without the need for explicit performance profiling. In a cluster of machines, Scalanytics further improves throughput through the use of a consistent-hashing based load partitioning strategy. Our evaluation on a 16-core machine demonstrate that Scalanytics achieves up to 11.4 $$\times $$ × improvement in throughput compared with the best uniprocessor implementation. Moreover, Scalanytics outperforms the Bro intrusion detection system by an order of magnitude when used for analyzing SMTP traffic. We further observed increased throughput when running Scalanytics pipelines across multiple machines.
Homothorax and Extradenticle alter the transcription factor network in Drosophila ommatidia at the dorsal rim of the retina

A narrow band of ommatidia in the dorsal periphery of the Drosophila retina called the dorsal rim area (DRA) act as detectors for polarized light. The transcription factor Homothorax (Hth) is expressed in DRA inner photoreceptors R7 and R8 and is both necessary and sufficient to induce the DRA fate, including specialized morphology and unique Rhodopsin expression. Hth expression is the result of Wingless (Wg) pathway activity at the eye margins and restriction to the dorsal eye by the selector genes of the Iroquois complex (Iro-C). However, how the DRA is limited to exactly one or two ommatidial rows is not known. Although several factors regulating the Drosophila retinal mosaic are expressed in DRA ommatidia, the role of Hth in this transcriptional network is uncharacterized. Here we show that Hth functions together with its co-factor Extradenticle (Exd) to repress the R8-specific factor Senseless (Sens) in DRA R8 cells, allowing expression of an ultraviolet-sensitive R7 Rhodopsin (Rh3). Furthermore, Hth/Exd act in concert with the transcriptional activators Orthodenticle (Otd) and Spalt (Sal), to activate expression of Rh3 in the DRA. The resulting monochromatic coupling of Rh3 between R7 and R8 in DRA ommatidia is important for comparing celestial e-vector orientation rather than wavelengths. Finally, we show that Hth expression expands to many ommatidial rows in regulatory mutants of optomotorblind (omb), a transcription factor transducing Wg signaling at the dorsal and ventral eye poles. Therefore, locally restricted recruitment of the DRA-specific factor Hth alters the transcriptional network that regulates Rhodopsin expression across ommatidia.
Biofilm development on leaf and wood surfaces in a boreal river

SUMMARY 1. Biofilms are organic layers that develop on submerged surfaces. They are composed of micro-organisms, exoenzymes, and detritus particles enclosed within a gelatinous matrix. While much is known about mineral surface biofilms, those developing on organic surfaces have not been extensively studied. We examined the influences of current velocity and substratum composition on biofilm development in a fourth-order North American boreal river. 2. Arrays of white birch ice-cream sticks and sugar maple leaves were placed at fast and slow current sites. Samples were collected periodically, analysed for mass loss, and assayed for microbial biomass (ATP, ergosterol, chlorophyll a) and exoenzyme activity associated with lignocellulose degradation (exo- and endocellulase, β-glucosidase, phenol oxidase, peroxidase). 3. Biofilms developed rapidly on both surfaces. On leaves, biomass peaked within 30 days of exposure. On wood, ATP and chlorophyll a concentrations peaked within 30–70 days, whereas ergosterol increased throughout the study (161 days). On leaves, current velocity had little influence on biofilm development, although breakdown rates were greater at the fast flow site. On wood, ATP and chlorophyll a concentrations were greater at the fast flow site, whereas ergosterol concentrations and breakdown rates were similar at both sites. Microbial biomass was consistently greater on wood than leaves, Exoenzyme activity developed rapidly on both surfaces; current velocity had little influence on activity. Except for β-glucosidase, activities were greater on wood than leaves. 4. Our results suggest that fungi are an important structuring element of organic surface biofilms and the physical stability of the substratum strongly influences biofilm development. Leaf surfaces are susceptible to softening and fragmentation, truncating biofilm development. In contrast, abrasion of wood surfaces removes senescent material exposing fresh substratum for colonization. Thus, wood surfaces with their greater physical stability, permit the development of more extensive biofilms. Wood surfaces may represent an overlooked but important site of metabolic activity in streams.
The National Ignition Campaign (NIC): Results and future plans

The 192-beam National Ignition Facility (NIF), a football-stadium sized laser at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now fully operational. With planned peak energy of 1.8 MJ in the ultraviolet, NIF will be approximately fifty times more energetic than any previous inertial confinement fusion (ICF) laser system. NIF has conducted 192-beam ICF implosion experiments with energies as high as 1.2 MJ, and has also demonstrated the unprecedented energy and pulse shaping control required for ignition experiments.
Spousal Leadership and Continuity in the Family Firm

CEO spouses play a key, even if often invisible, role in most family-controlled corporations. This is particularly true when the special challenges of succession and continuity become evident. This paper proposes a typology of spouse styles and their possible influence on succession and continuity.
Cdk1 uncouples CtIP-dependent resection and Rad51 filament formation during M-phase double-strand break repair

DNA double-strand break (DSB) resection, which results in RPA-bound single-stranded DNA (ssDNA), is activated in S phase by Cdk2. RPA-ssDNA activates the ATR-dependent checkpoint and homology-directed repair (HDR) via Rad51-dependent mechanisms. On the other hand, the fate of DSBs sustained during vertebrate M phase is largely unknown. We use cell-free Xenopus laevis egg extracts to examine the recruitment of proteins to chromatin after DSB formation. We find that S-phase extract recapitulates a two-step resection mechanism. M-phase chromosomes are also resected in cell-free extracts and cultured human cells. In contrast to the events in S phase, M-phase resection is solely dependent on MRN-CtIP. Despite generation of RPA-ssDNA, M-phase resection does not lead to ATR activation or Rad51 chromatin association. Remarkably, we find that Cdk1 permits resection by phosphorylation of CtIP but also prevents Rad51 binding to the resected ends. We have thus identified Cdk1 as a critical regulator of DSB repair in M phase. Cdk1 induces persistent ssDNA-RPA overhangs in M phase, thereby preventing both classical NHEJ and Rad51-dependent HDR.
Multi-user schemes using nonlinear time-varying modulation

We propose to optimally reduce multiple access interference in multi-user systems using modulation schemes based on time-varying signals with nonlinear phase functions. This minimization is achieved by deriving constraints on the frequency modulation parameters of these signals. The success of the new method over frequency-shift keying signaling is demonstrated in frequency-hopped code division multiple access (FH-CDMA) systems. In addition, we propose to estimate the transmitted symbol information at the receiver using time-varying processing techniques based on unitary versions of the optimal periodogram spectral estimator.
Consumer Trust in Information Sources: Testing an Interdisciplinary Model

Trust is essential to understanding public reaction to innovative issues. This research focuses on trust in information sources by explicating the construct of trust and testing a comprehensive model on several information sources about genetically modified foods. Results from a survey of 369 participants reveal the significance of projecting competence and the role of the environment in which a target public receives information. Perceptions of regulatory, social, business, and technical environments affect how likely individuals are to follow advice from institutions like the Food and Drug Administration and the news media. Future research should incorporate knowledge levels and personal relevance as variables likely to influence trusting relationships.
Construction and analysis of non-Poisson stimulus-response models of neural spiking activity.

A paradigm for constructing and analyzing non-Poisson stimulus-response models of neural spike train activity is presented. Inhomogeneous gamma (IG) and inverse Gaussian (IIG) probability models are constructed by generalizing the derivation of the inhomogeneous Poisson (IP) model from the exponential probability density. The resultant spike train models have Markov dependence. Quantile-quantile (Q-Q) plots and Kolmogorov-Smirnov (K-S) plots are developed based on the rate-rescaling theorem to assess model goodness-of-fit. The analysis also expresses the spike rate function of the neuron directly in terms of its interspike interval (ISI) distribution. The methods are illustrated with an analysis of 34 spike trains from rat CA1 hippocampal pyramidal neurons recorded while the animal executed a behavioral task. The stimulus in these experiments is the animal's position in its environment and the response is the neural spiking activity. For all 34 pyramidal cells, the IG and IIG models gave better fits to the spike trains than the IP. The IG model more accurately described the frequency of longer ISIs, whereas the IIG model gave the best description of the burst frequency, i.e. ISIs < or = 20 ms. The findings suggest that bursts are a significant component of place cell spiking activity even when position and the background variable, theta phase, are taken into account. Unlike the Poisson model, the spatial and temporal rate maps of the IG and IIG models depend directly on the spiking history of the neurons. These rate maps are more physiologically plausible since the interaction between space and time determines local spiking propensity. While this statistical paradigm is being developed to study information encoding by rat hippocampal neurons, the framework should be applicable to stimulus-response experiments performed in other neural systems.
Knockout of 5‐lipoxygenase prevents dexamethasone‐induced tau pathology in 3xTg mice

Emerging evidence suggests that dysregulation stress hormones, such as glucocorticoids, in aged persons put them at a higher risk to develop Alzheimer's disease (AD). However, the mechanisms underlying such vulnerability remain to be unraveled. Pharmacologic inhibition of 5-lipoxygenase (5LO), an active player in AD pathogenesis whose protein level increases with aging in the human, has been shown to blunt glucocorticoid-mediated amyloid β (Ab) formation in vitro. In this article, we investigated the role of this pathway in modulating the development of the corticosteroid-dependent AD-like phenotype in the triple transgenic mice (3xTg). Dexamethasone was administered for 1 week to 3xTg or 3xTg genetically deficient for 5LO (3xTg/5LO-/-) mice, and its effect on memory, amyloid-β and tau levels, and metabolism assessed. At the end of the treatment, we observed that dexamethasone did not induce changes in behavior. Compared with controls, treated mice did not show significant alterations in brain soluble Aβ levels. While total tau protein levels were unmodified in all groups, we found that dexamethasone significantly increased tau phosphorylation at S396, as recognized by the antibody PHF-13, which was specifically associated with an increase in the GSK3β activity. Additionally, dexamethasone-treated mice had a significant increase in the tau insoluble fraction and reduction in the postsynaptic protein PDS-95. By contrast, these modifications were blunted in the 3xTg/5LO-/- mice. Our findings highlight the functional role that 5LO plays in stress-induced AD tau pathology and support the hypothesis that pharmacologic inhibition of this enzyme could be a useful tool for individuals with this risk factor.
The Swift Trust Partnership: A Project Management Exercise Investigating the Effects of Trust and Distrust in Outsourcing Relationships

The Swift Trust exercise provides instructors with the opportunity to discuss the issues of managing trust and distrust perceptions in a team-based design. Lewicki, McAllister, and Bies’s (1998) framework is used to allow students to experience the difficulties of deriving a common set of contract requirements based on team dynamics and reputational factors of a potential future trading partner. This interteam exercise provides instructors with a medium-term simulation (from three to four class periods) that can be used to discuss integrating simultaneous trust and distrust perceptions. Discussion of pedagogical issues and implications is provided to assist instructors in conducting this exercise.
A tight signal-band power bound on mismatch noise in a mismatch-shaping digital-to-analog converter

Many applications employ digital-to-analog converters (DACs) to obtain the advantages of digital processing (e.g., low power and physical size, resilience to noise, etc.) to generate signals, such as voltages, that are analog in nature. Given the appropriate numerical representation of its input, the DAC ideally behaves as a linear gain element. However, as a result of inevitable component mismatches, the output of a multibit DAC (i.e., a DAC designed to output more than two analog levels) is a nonlinear function of its input. The resulting distortion, called DAC noise , limits the overall signal-to-noise ratio (SNR) and hence the obtainable accuracy of the DAC. Mismatch-shaping DACs exploit built-in redundancy to suppress the DAC noise in the input signal's frequency band. Although mismatch-shaping DACs are widely used in commercial products, little theory regarding the structure of their DAC noise has been published to date. Consequently, designers have been forced to rely upon simulations to estimate DAC noise power and behavior, which can be misleading because the DAC noise depends on the DAC input. This paper addresses this problem. It presents an analysis of the DAC noise power spectral density (PSD) in a commonly used mismatch-shaping DAC: the dithered first-order low-pass tree-structured DAC. This design ensures that its DAC noise has a spectral null at dc (i.e., zero frequency) by generating digital, dc-free sequences using the same techniques that have been developed for line codes. An expression is derived for the DAC noise PSD that depends on the statistics of these sequences and is used to show various properties of the DAC noise. Specifically, an attainable bound is derived for the signal-band DAC noise power that can be used to predict worst case performance in practical circuits.
Photoelectron spectroscopic study of the ethyl cyanoacrylate anion

Abstract Anion photoelectron spectroscopy and density functional theory have been utilized to study the parent, ethyl cyanoacrylate molecular anion, ECA − . The measured electron affinity (0.9 ± 0.2 eV), vertical detachment energy (1.3 ± 0.1 eV), and anion-to-triplet neutral, photodetachment transition energies (4.0 ± 0.1 eV and 4.5 ± 0.1 eV) all compare well with their calculated values. The relatively high electron affinity of the ECA monomer is responsible for the fact that its “anionic” polymerization mechanism proceeds even with weak nucleophiles, such as water.
Declining enrollments-a 'now' strategy for the future

The author examines ways that college instructors might be able to reach down to the grade-school level to inspire young students to follow a path to engineering schools and ultimately to the engineering profession. A practical example is given that will demonstrate how one can make that path visible and exciting by providing means by which these youngsters can have measures of success with 'hands on' activity. It is the author's belief that once these young people become focused on engineering, it will be difficult to keep them out of engineering classrooms of the future. >