cssi/SciSciGPT-SciSciNet huggingface dataset:
Stochastic Modeling of Gravity Compensation Error in GNSS-Aided Inertial Navigation Systems

GNSS-aided inertial navigation systems (INS) are used in a variety of aerospace applications as robust sources of position, velocity, attitude, and time. Due to the safety-critical nature of civil aviation applications, navigation systems must be rigorously tested to ensure they will not output hazardously misleading information (HMI). RTCA, a standards-making organization, develops documents containing requirements and testing guidance for manufacturers of equipment installed on aircraft. RTCA Special Committee 159 has organized a working group (WG-2C) to develop a new Minimum Operational Performance Standard (MOPS) that addresses GNSS-aided INS. The new MOPS will accommodate a wide performance range of inertial sensors (e.g., tactical as well as navigation grade), and it will cover accuracy and integrity coasting performance during GNSS outages. As part of the focus on coasting performance during GNSS outages, WG-2C is investigating the effects of gravity modeling error on the aided-inertial solution. The portion of gravity deflection not accounted for in the navigation system by a model or database results in horizontal acceleration error that integrates to become velocity and position error. Previous research by the authors [1] has shown that unmodeled gravity deflections can induce up to 200 meters of position error, which is a non-negligible portion of an RNP 0.3 or less lane-width. Additional work by the authors [2] showed that even if a worldwide high fidelity model such as EGM2008 is used, the commission and omission errors of the model still remain in the acceleration estimates after compensation. This paper first presents deflection of the vertical (DOV) profiles for real RNP airport approaches to demonstrate realistic severe situations for GNSS-coasting. Next, low and high order gravity models are implemented and the statistics of the residuals are studied. Finally, system identification techniques are used to analyze the gravity model residuals and develop stochastic processes that are statistically representative of these residuals. Second-order autoregressive models are identified, and model parameters are dynamically drawn from the numerically derived statistical distributions to account for the non-stationary nature of the residuals.
Interpretation Training Needs in the 21st Century: A Needs Assessment of Interpreters in the National Park Service:

To identify critical training needs in the Interpretation and Education (I&E) Division within the National Park Service (NPS), a team of experts and practitioners, including six academic institutio...
Fast Structuring of Radio Networks Large for Multi-message Communications

We introduce collision free layerings as a powerful way to structure radio networks. These layerings can replace hard-to-compute BFS-trees in many contexts while having an efficient randomized distributed construction. We demonstrate their versatility by using them to provide near optimal distributed algorithms for several multi-message communication primitives. Designing efficient communication primitives for radio networks has a rich history that began 25 years ago when Bar-Yehuda et al. introduced fast randomized algorithms for broadcasting and for constructing BFS-trees. Their BFS-tree construction time was OD log2 n rounds, where D is the network diameter and n is the number of nodes. Since then, the complexity of a broadcast has been resolved to be $T_{BC} = \ThetaD \log \frac{n}{D} + \log^2 n$ rounds. On the other hand, BFS-trees have been used as a crucial building block for many communication primitives and their construction time remained a bottleneck for these primitives. We introduce collision free layerings that can be used in place of BFS-trees and we give a randomized construction of these layerings that runs in nearly broadcast time, that is, w.h.p. in $T_{Lay} = OD \log \frac{n}{D} + \log^{2+\epsilon} n$ rounds for any constant e>0. We then use these layerings to obtain: 1 A randomized algorithm for gathering k messages running w.h.p. in OT Lay +k rounds. 2 A randomized k-message broadcast algorithm running w.h.p. in OT Lay +k logn rounds. These algorithms are optimal up to the small difference in the additive poly-logarithmic term between T BC and T Lay . Moreover, they imply the first optimal On logn round randomized gossip algorithm.
A computationally efficient approach for the removal of the phase shift singularity in harmonic resolvent analysis

The recently introduced harmonic resolvent framework is concerned with the study of the input-output dynamics of nonlinear flows in the proximity of a known time-periodic orbit. These dynamics are governed by the harmonic resolvent operator, which is a linear operator in the frequency domain whose singular value decomposition sheds light on the dominant input-output structures of the flow. Although the harmonic resolvent is a mathematically well-defined operator, the numerical computation of its singular value decomposition requires inverting a matrix that becomes exactly singular as the periodic orbit approaches an exact solution of the nonlinear governing equations. The very poor condition properties of this matrix hinder the convergence of classical Krylov solvers, even in the presence of preconditioners, thereby increasing the computational cost required to perform the harmonic resolvent analysis. In this paper we show that a suitable augmentation of the (nearly) singular matrix removes the singularity, and we provide a lower bound for the smallest singular value of the augmented matrix. We also show that the desired decomposition of the harmonic resolvent can be computed using the augmented matrix, whose improved condition properties lead to a significant speedup in the convergence of classical iterative solvers. We demonstrate this simple, yet effective, computational procedure on the Kuramoto-Sivashinsky equation in the proximity of an unstable time-periodic orbit.
A seq2seq model to forecast the COVID-19 cases, deaths and reproductive R numbers in US counties

The global pandemic of coronavirus disease 2019 (COVID-19) has killed almost two million people worldwide and over 400 thousand in the United States (US). As the pandemic evolves, informed policy-making and strategic resource allocation relies on accurate forecasts. To predict the spread of the virus within US counties, we curated an array of county-level demographic and COVID-19-relevant health risk factors. In combination with the county-level case and death numbers curated by John Hopkins university, we developed a forecasting model using deep learning (DL). We implemented an autoencoder-based Seq2Seq model with gated recurrent units (GRUs) in the deep recurrent layers. We trained the model to predict future incident cases, deaths and the reproductive number, R . For most counties, it makes accurate predictions of new incident cases, deaths and R values, up to 30 days in the future. Our framework can also be used to predict other targets that are useful indices for policymaking, for example hospitalization or the occupancy of intensive care units. Our DL framework is publicly available on GitHub and can be adapted for other indices of the COVID-19 spread. We hope that our forecasts and model can help local governments in the continued fight against COVID-19.
Evaluating the effect of city ordinances on the implementation and performance of green stormwater infrastructure (GSI)

Abstract The replacement of natural pervious surfaces with impervious surfaces due to urbanization, construction, and development causes excess stormwater runoff and results in cities experiencing localized flooding events. The installation of green stormwater infrastructure (GSI) is one way of reducing flooding events and preventing downstream erosion and damage. In this study, computer rainfall-runoff simulations were performed to analyze GSI's effectiveness in mitigating stormwater runoff when applied to sites with different soil types and for which different design storms were established by regulation. A mixed-use development site was used as a hypothetical site on which to perform the analysis. The study applied the same design to six small- to medium-sized cities in the southeastern United States with different design storm magnitudes. The cities’ ordinances were reviewed, and none required GSI. Therefore, this study revised some of the stormwater management requirements to stress GSI implementation, and then stormwater modeling was conducted to see how regulatory changes would affect runoff. The HydroCAD stormwater modeling tool was used to perform hydrologic simulations for the hypothetical building site in each of the six cities using the design storms and small storms of the cities. Even though GSI has been commonly implemented in large cities, small and medium-sized cities can also prevent excess stormwater by incorporating GSI in their ordinances for new developments and site retrofits. Based on the hydrologic simulation results, municipalities with lower magnitude design storms and low infiltration soils have the most to benefit from GSI and could benefit from ordinances requiring GSI. For smaller, more frequent storms, GSI alone can meet the pre-development peak flow requirements.
Impacts of manganese oxides on molybdenum and tungsten speciation and implications for their geochemistry in aquatic environments

Abstract Molybdenum (Mo) and tungsten (W) concentration patterns and isotope signatures are widely used to study changes in ocean redox conditions. This is in part due to the differential adsorption of Mo and W onto various types of minerals that are abundant under different redox regimes. The speciation of Mo and W, which also varies under different redox conditions, greatly controls their particle reactivities in the environment. Manganese (Mn) oxide minerals can not only provide surfaces for Mo and W adsorption, but also catalyze Mo and W speciation change. Thus, the Mn oxides that are often present at redox interfaces can play an important role in Mo and W speciation change. However, we lack knowledge of how rates for Mn oxide catalyzed Mo and W speciation transformation compare to rates for their adsorption and isotope fractionation processes, which creates uncertainty in our ability to interpret Mo and W concentration and isotope patterns in sediments and sedimentary rocks. Here, we present data that constrain rates, environmental controls, and mechanisms for tetrathiomolybdate (MoS42–) and tetrathiotungstate (WS42–) hydrolysis on Mn oxide surfaces, which transforms the thioanion species to oxyanion species. The experimental results show that hydrolysis rate constants for these Mo and W thioanions are first order with respect to Mn oxide surface areas. Hence, high abundance of Mn oxides in aquatic environments greatly catalyzes MoS42– and WS42– hydrolysis. In addition, experimental results indicate that crystal structure differences of Mn oxides contribute to differences in rates for Mo and W thioanion hydrolysis reactions. Solution pH and ionic strength have limited impacts on Mo and W thioanion hydrolysis rates catalyzed by Mn oxides, while sulfate has a moderate impact. Geochemical modeling results indicate that equilibrium times for MoS42– and WS42– hydrolysis reactions in the presence of Mn oxides at abundances found in the modern ocean are three orders of magnitude longer than those for adsorption and isotope fractionation of Mo and W on Mn oxide surfaces. This implies that Mn oxides play a larger role in affecting adsorption and isotope fractionation processes than Mo and W speciation transformation in the modern, well-oxygenated ocean. In contrast, the potentially high levels of dissolved Mn(II) in the Archean ocean would have shortened the equilibrium time for Mo or W speciation transformation such that this process could compete with their adsorption and isotope fractionation processes, and subsequently affect sedimentary Mo and W isotope records. The impact of dissolved Mn(II) catalyzed Mo and W speciation change should be considered in future studies of Archean Mo and W isotope records.
FAILURE OF PANCREATIC ALPHA CELLS TO RESPOND TO HYPOGLYCEMIA IS LINKED TO IMPAIRED GLUTAMATE RECEPTOR SIGNALING IN DIABETES

Glucagon secretion from the pancreatic alpha cells is crucial to prevent hypoglycemia. People with type 1 diabetes, however, lose this glucoregulatory mechanism and are susceptible to dangerous insulin treatment-induced hypoglycemia. We established that activating glutamate receptors of the AMPA/kainate type in alpha cells is needed for decreases in glucose levels to elicit full glucagon responses from mouse and human islets. We performed functional studies using living pancreas slices from donors with type 1 diabetes and found that alpha cells had normal glucagon content and responded typically to KCl depolarization, but failed to respond to decreases in glucose concentration and had severely impaired AMPA/kainate receptor signaling. Reactivating residual AMPA/kainate receptor function with the positive allosteric modulators cyclothiazide and aniracetam partially rescued glucagon secretion in response to hypoglycemia. Positive allosteric modulators of AMPA/kainate receptors already approved to treat other conditions could thus be repurposed to prevent hypoglycemia and improve management of diabetes.
Chromosomal instability and aneuploidy as causes of cancer drug resistance

High levels of aneuploidy and chromosomal instability (CIN) are correlated with poor patient outcomes, though the mechanism(s) underlying this relationship have not been established. Recent evidence has demonstrated that chromosome copy number changes can function as point mutation-independent sources of drug resistance in cancer, which may partially explain this clinical association. CIN generates intratumoral heterogeneity in the form of gene dosage alterations, upon which the selective pressures induced by drug treatments can act. Thus, although CIN and aneuploidy impair cell fitness under most conditions, CIN can augment cellular adaptability, establishing CIN as a bet-hedging mechanism in tumor evolution. CIN may also endow cancers with unique vulnerabilities, which could be exploited therapeutically to achieve better patient outcomes.
Theories of Democratic Change III: Transitions from Conflict

The notion that robust democracy and violent conflict are linked is commonplace. Many observers of international politics attribute violent conflict in contexts as diverse as Myanmar and Syria to failures of democracy. Conversely, most agree that continuing political violence undermines any effort to build strong democratic institutions in Libya or South Sudan. As a matter of policy, democratization has often been promoted not only as an end in itself but as a means toward building peace in societies scarred by violence. Development professionals tackle these challenges daily, confronting vicious cycles of political violence and weak democratic institutions. At the same time, scholars have dedicated intense scrutiny to these questions, often finding that the interrelationships between conflict and democracy belie easy categorization. This report, the third in a series on democratic theories of change, critically engages with this literature to ask three questions: Under what circumstances do democratic practice or movement toward democracy quell (or exacerbate) the risk of different kinds of violent conflict? Under what circumstances do the risk and experience of violent conflict undermine democratic practice? How can external interventions mitigate risks and capitalize on opportunities inherent in transitions to democracy and peace? To answer these questions, a research team at George Mason University and Georgetown University spent eight months compiling, organizing, and evaluating the academic literature connecting democratic practice and violent conflict, which spans the fields of political science, economics, peace studies, anthropology, sociology, and psychology. This work was funded by USAID’s Center of Excellence on Democracy, Human Rights, and Governance (the DRG Center), under the Institute of International Education’s (IIE’s) Democracy Fellows and Grants Program. Beginning in May 2018, the authors organized a team of three research assistants, who read and summarized more than 600 journal articles, books, reports, and newspaper articles. The resulting White Paper was the subject of an August 2018 workshop with representatives from USAID and an interdisciplinary group of eight scholars with expertise in conflict and democracy. Based on their feedback, the authors developed a new Theories of Change Matrix and White Paper in October 2018. This draft received further written feedback from USAID and another three scholars. The core team then revised the report again to produce this final draft. This report’s approach to the literature differs from past phases of the Theories of Democratic Change project. While past reports detailed the hypothesized causes of democratic backsliding (Phase I) and democratic transitions (Phase II), this report focuses on the reciprocal relationship between democratic practice and conflict. The report therefore organizes hypotheses into two questions and then sub-categories within each question.
An Empirical Analysis of Explanation-Based Learning

This chapter discusses experiments that investigate whether it is better to learn a number-generalized rule or to individually learn the subsumed fixed-number rules as they are needed. A secondary question focuses on whether explanation-based learning is worthwhile at all. Two different training strategies are analyzed, along with several variants of the basic experiments. The two basic experiments compare systems that learn from their own problem solving to systems that learn by observing the actions of external agents. The experimental results indicate that substantially better performance can be achieved by observing the behavior of external agents. The problem generator creates an initial situation by generating 10 blocks, each with a randomly-chosen width and height. One at a time, it drops them from an arbitrary horizontal position over a table; if one falls in an unstable location, it picks up the block and re-releases it over a new location.
Network Structure and Activity in Boolean Networks

In this paper we extend the notion of activity for Boolean networks introduced by Shmulevich and Kauffman (2004). Unlike the existing notion, we take into account the actual graph structure of the Boolean network. As illustrations, we determine the activity of all elementary cellular automata, and \(d\)-regular trees and square lattices where the vertex functions are bi-threshold and logical nor functions.
Long-Term Follow-Up and Survivorship

The term “cancer survivor” includes the spectrum of newly diagnosed patients to those decades out of therapy. The American College of Surgeon’s Commission on Cancer requires all patients to be provided with a comprehensive summary, or care plan, at completion of their therapy. Efforts to enhance the quality of life for hematopoietic stem cell transplant (HSCT) survivors have been coordinated by the National Marrow Donor Program, the American Society for Blood and Marrow Transplant, the European Group for Blood and Marrow Transplantation, and the Center for International Blood and Marrow Transplant Research, along with patient advocacy groups such as the National Bone Marrow Transplant Link.
Chapter 1 Beam Processing of Silicon

Publisher Summary This chapter reviews the basic mechanisms by which beam annealing proceeds and discusses the basic metallurgical and electronic properties of beam-annealed material. Two distinctly different beam-annealing mechanisms have been identified, depending on the duration of the beam exposure. For Q -switched lasers or pulsed electron beams, exposure times are typically in the range of 5 ns–500 ns, and the annealing process then involves the formation of a thin surface layer of molten silicon that recrystallizes on the underlying substrate when the radiation is removed. If the irradiated sample is an ion implanted single crystal and the depth of the molten layer is sufficient to envelop the implantation damaged region, the molten layer regrows by a liquid phase epitaxial process on the crystalline substrate to produce material with a very high degree of structural perfection and very superior electronic properties. For CW systems, on the other hand, the silicon surface is typically exposed to the beam for 0.1–10 ms and, in some cases, for several tens of seconds.
Modifications and improvements to the Sea Beam system on board R/V Thomas Washington

A number of modifications to the narrowbeam echo-sounder and echo processor of the Sea Beam multibeam bathymetric survey system have been implemented. These include the design and construction of a digital pitch compensator, the ability to use a variety of sensors for vertical reference, the design and construction of hardware test equipment, and an interface to the shipboard DEC VAX-11/730 computer for data logging, automation of start-up procedures, and performance monitoring. >
We Can Work It Out: Entertaining a Dispute Resolution System Design for Bankruptcy Court

The development of a dispute resolution system design for Bankruptcy Court is actually an ongoing mediation among the stakeholders and dispute resolution designers. The goal is to clarify, prioritize and mediate the values that will shape the design of a responsive bankruptcy dispute resolution system. How do you design a program that incorporates the requisite efficiency that is a hallmark of bankruptcy court while still honoring the values of party-choice, party self-determination and fairness of process that are coveted by dispute resolution professionals? This article distills the rich conversation between bankruptcy jurists and dispute resolution scholars at “ADR Meets Bankruptcy: Cross-Purpose or Cross Pollination?” sponsored by the American Bankruptcy Law review, the Hugh L. Carey Center for Dispute Resolution and St. John’s Institute for Bankruptcy Policy on October 2, 2009.
Cygnus X-3

The low-mass X-ray binary Cyg X-3 is unusual for its high radio, infrared, and X-ray luminosities. This paper reviews the observational situation at all wavelengths, and reports the first results of a series of coordinated observations at all wavelengths.
Network vulnerability analysis

The increasing volume of attacks on the Internet has increased the demand for sophisticated tools for vulnerability analysis, intrusion detection, forensic investigations, and possible responses. Current hacker tools and technologies warrant reengineering to address cyber crime and homeland security. The creation of network scanners is necessary to secure the information infrastructure by gathering network topology, intelligence, internal/external vulnerability analysis, and penetration testing. Scanners must be able to function on a variety of networks: Internet (IP), SS7, wireless, and converged networks. Scanners should be extendable and upgradable to facilitate use by a broad spectrum of users and platforms; such flexibility allows users to keep up with current hacker technology. This paper describes one such scanner, referred to as NetGlean.
Microsphere-based immunoassay integrated with a microfluidic network to perform logic operations

Lab on a chip (LOC) intelligent diagnostics can be described by molecular logic-based circuits. We report on the development of an LOC approach with logic capability for screening combinations of antigen and antibody in the same sample. A microsphere-based immunoassay was integrated with a microfluidic network device to perform the logic operations AND and INHIBIT. Using the clinically relevant biomarkers TNF-α cytokine and anti-TNF-α antibody, we obtained a fluorescent output in the presence of both inputs. This results in an AND operation, while the presence of only one specific input results in a different fluorescent signal, thereby indicating the INHIBIT operation. This approach demonstrates the effective use of molecular logic computation for developing portable, point-of-care technologies for diagnostic purposes due to fast detection times, minimal reagent consumption and low costs. This model system may be further expanded to screening of multiple disease markers, combinatorial logic applications, and developing “smart” sensors and therapeutic technologies.
Rigid-body motion, interacting billiards, and billiards on curved manifolds.

It is shown that the free motion of any three-dimensional rigid body colliding elastically between two parallel, flat walls is equivalent to a three-dimensional billiard system. Depending upon the inertial parameters of the problem, the billiard system may possess a potential energy field and a non-Euclidean configuration space. The corresponding curvilinear motion of the billiard ball does not necessarily lead to a decrease of the stable periodic orbits found in the analogous rectilinear system.
Pivoting neuromuscular control and proprioception in females and males

Noncontact ACL injuries occur most commonly in pivoting sports and are much more frequent in females than in males. However, information on sex differences in proprioceptive acuity under weight-bearing and leg neuromuscular control in pivoting is scarce. The objective of this study was to investigate sex differences in pivoting neuromuscular control during strenuous stepping tasks and proprioceptive acuity under weight-bearing. 21 male and 22 female subjects were recruited to evaluate pivoting proprioceptive acuity under weight-bearing, and pivoting neuromuscular control (in terms of leg pivoting instability, stiffness, maximum internal and external pivoting angles, and entropy of time-to-peak EMG in lower limb muscles) during strenuous stepping tasks performed on a novel offaxis elliptical trainer. Compared to males, females had significantly lower proprioceptive acuity under weight-bearing in both internal and external pivoting directions, higher pivoting instability, larger maximum internal pivoting angle, lower leg pivoting stiffness, and higher entropy of time-to-peak EMG in the gastrocnemius muscles during strenuous stepping tasks with internal and external pivoting perturbations. Results of this study may help us better understand factors contributing to ACL injuries in females and males, develop training strategies to improve pivoting neuromuscular control and proprioceptive acuity, and potentially reduce ACL and lower-limb musculoskeletal injuries.
Tyrosine phosphorylation in mouse mammary hyperplasias

Tyrosine phosphorylation status was investigated during mouse mammary tumor development using non-tumorigenic and tumorigenic hyperplastic outgrowth lines. These outgrowth lines were compared with normal mammary glands from pregnant mice and with their corresponding tumors. The levels of total tyrosine phosphorylation in proteins of hyperplastic and neoplastic tissues were 4.7- and 3.4-fold higher than in the normal gland respectively. These results indicate that increases in tyrosine phosphorylation occur in the earliest stages of neoplastic development and are not restricted to neoplastic cells per se. These results led to the identification of the specific proteins showing high levels of tyrosine phosphorylation. Of the eight molecular weight bands of proteins exhibiting detectable levels of tyrosine phosphorylation, the only proteins exhibiting consistently different degrees of phosphorylation between hyperplasias and tumors were of ∼34 kDa. In a series of six different hyperplasias with tumorigenic potentials ranging from 0 to 93%, the extent of tyrosine phosphorylation of 34 kDa proteins correlated inversely with tumorigenic potential. The levels of p34 cdc2 and p33 cdk2 proteins were examined, using antibodies specific for the cdc2 and cdk2 proteins. The amounts of p34 cdc2 and p33 cdk2 proteins were low in non-tumorigenic (TM3 and TM2L) compared to tumorigenic hyperplasias and correlated inversely with tyrosine phosphorylation of 34 kDa proteins during tumor development. Thus in the non-tumorigenic hyperplasias (TM2L and TM3) the majority of p34 cdc2 was phosphorylated on tyrosine, in contrast to the p34 cdc2 in tumorigenic (TM2H) hyperplasias and tumors. Two-dimensional PAGE analysis of mammary tumor samples with antibodies specific to cdc2, cdk2 and phosphorylated tyrosine revealed one p34 cdc2 form, two p33 cdk2 isoforms and two phosphotyrosine isoforms of about 33-34 kDa. The results suggest that the high levels of tyrosine phosphorylation in cdc2 and cdk2 reflect the low tumorigenic potential of a subset of mammary preneoplastic hyperplasias. This interpretation is in accord with current concepts on the role of tyrosine phosphorylation in the regulation of the cyclin-dependent kinases
Phenomenal consciousness: the explanatory gap as a cognitive illusion

The thesis that there is a troublesome explanatory gap between the phenomenal aspects of experiences and the underlying physical and functional states is given a number of different interpretations. It is shown that, on each of these interpretations, the thesis is false. In supposing otherwise, philosophers have fallen prey to a cognitive illusion, induced largely by a failure to recognize the special character of phenomenal concepts.
Acceptable weights and physiological costs of performing combined manual handling tasks in restricted postures.

Eight healthy, male underground coal miners (mean age=36·9 yrs±4·5 SD) participated in a study examining psychophysical acceptable weights and physiological costs of performing combined lifting and lowering tasks in restricted headroom conditions. Independent variables included posture (stooping or kneeling on two knees), task symmetry (symmetric or asymmetric), and vertical lift distance (35 cm or 60cm). All tasks were 10min in duration and were performed under a 1·22 m ceiling to restrict the subject's posture. Subjects were required to raise and lower a lifting box every 10 s, and asked to adjust the box weight to the maximum amount they could handle without undue strain or fatigue. During the final 5 min of each test, data were collected to determine the energy expenditure requirements of the task. Results of this study demonstrated that psychophysical lifting capacity averaged 11·3% lower when kneeling as compared to stooping. Subjects selected 3·5% more weight in asymmetric tasks, and lifted 5·0% le...
Natural charge densities for the evaluation of MC-SCF energy derivatives without density matrix transformation

Abstract A technique is described which allows the construction of the reduced two-electron density matrix “on the fly” in MC-SCF derivative calculations. The method eliminates the problems associated with the storage and access of a large density matrix file, and incurs only a small computational overhead for active spaces of moderate dimension (up to 12).
Evaluating Osmia cornifrons as Pollinators of Highbush Blueberry

The objective of this study was to investigate the use of Osmia cornifrons Radoszkowski (hornfaced bees) as a pollinator of Vaccinium corymbosum L. (highbush blueberry). Currently, there are no reports available on hornfaced bee use for commercial blueberry production. Five pollination treatments were compared in a 2-year evaluation (2005–06) including hornfaced bees, honeybees, bumblebees, native pollinators, and no pollinators. Enclosed pollination cages were constructed around mature, field-grown highbush blueberry plants to prevent mixing of pollination treatments. Each cage contained a single pollination treatment, except for the open pollination and no pollination treatments. The five pollination treatments were replicated three times inside separate pollination field cages on the farm. Three branches per plant were randomly selected that had a minimum of five fruiting buds and blossom number was recorded. After pollination occurred, the cages were removed to allow the berries to ripen. Ripe fruits ...
Colloid particle sizes in the Mississippi River and some of its tributaries, from Minneapolis to below New Orleans

An on-board technique was developed that combined discharge-weighted pumping to a high-speed continuous-flow centrifuge for isolation of the particulate-sized material with ultrafiltration for isolation of colloid-sized material. In order to address whether these processes changed the particle sizes during isolation, samples of particles in suspension were collected at various steps in the isolation process to evaluate changes in particle size. Particle sizes were determined using laser light-scattering photon correlation spectroscopy and indicated no change in size during the colloid isolation process. Mississippi River colloid particle sizes from twelve sites from Minneapolis to below New Orleans were compared with sizes from four tributaries and three seasons, and from predominantly autochthonous sources upstream to more allochthonous sources downstream. © 1998 John Wiley & Sons, Ltd.
A comparison of two methods for measuring phosphate uptake by Monochrysis lutheri droop grown in continuous culture

Two methods for measuring phosphate uptake by phosphate-limited continuous cultures of Monochrysis lutheri Droop are found to yield comparable results. Data from both isotopic tracer (33P) and disappearance experiments strongly support a Michaelis- Menten-type hyperbolic relationship between instantaneous uptake rate and ambient phosphate concentration. The data show no systematic linear trend in either the maximum uptake rate per cell or its associated half saturation constant with pre-conditioning steady state growth rate; a weak non-linear trend with pre-conditioning may, however, be present in the maximum uptake rate with an apparent maximum at intermediate growth rates.
The potential benefits of herbicide-resistant transgenic rice in Uruguay: Lessons for small developing countries

Abstract In many developing countries, the potential benefits from adopting a transgenic variety developed by a multinational corporation are limited by the crop’s small production base. This paper presents an ex-ante evaluation of the economic impact of herbicide resistant transgenic rice in a small developing country, Uruguay. To fully account for the multinational’s market power, the firm’s seed markup is assumed to affect the adoption rate for the variety. Stochastic simulation techniques are employed to understand how potential benefits may vary with changes in technology, yield, costs, and adoption parameters. The results indicate a $1.82 million mean net present value for producers from the development and utilization of transgenic rice in Uruguay and $0.55 million for the multinational. These relatively small multinational firm benefits suggest that a firm will not undertake significant efforts to develop transgenic varieties adapted to local conditions without either strategic partnerships with local institutions or access to wider regional markets.
An analytic and experimental comparison of direct and external modulation in analog fiber-optic links

Analytic lumped-element small-signal models of directly and externally modulated analog fiber-optic links are derived. Incremental modulation efficiency is defined and used to compare the performances of these modulation techniques. In experiments to optimize link RF-to-RF gain and noise figure, the measurements obtained agreed with calculations to within approximately=1 dB. The externally modulated link was operated with two different impedance matching circuits. With a low-pass match the bandwidth was 150 MHz, and the link transducer gain was 1 dB; with a bandpass match the bandwidth was 22 MHz, the link transducer gain was 11 dB, and the noise figure was 6 dB. The directly modulated link was operated with a low-pass match. In this case, the bandwidth was 1 GHz, the link transducer gain was -14 dB, and the noise figure was 33 dB. These experimental results were achieved with no amplification,. >
Participatory model assessment of earthquake-induced landslide hazard models

The study described in this paper investigates the relative merits of two peer-reviewed earthquake-induced landslide models using participatory model assessment. The earthquake-induced landslide hazard models assessed are a simplified Newmark’s displacement model and a recently developed knowledge-based model. Participatory model assessment involves conducting facilitated participatory processes where the model(s) are used for aiding decisions within a socio-behavioral experiment designed for collecting data to evaluate formal hypotheses about the model(s). The paper sets out the design of the participatory model assessment—a series of workshops involving experts and potential model end-users that incorporated a roleplay site selection task. Quantitative data elicited using a set of entrance and exit questionnaires were analyzed to investigate hypotheses about the models. Participants found the knowledge-based model to be significantly more complete and more informative for their roleplay task. Overall, the two models did not yield significant differences with respect to issues such as task efficiency or task outcome satisfaction. Lastly, it was found that education level and disciplinary perspectives (of those analyzed) did not significantly affect outcomes, suggesting that a wide demographic of participants can be used for participatory model assessments. Additional research is needed to assess the models in different contexts, as well as more broadly developing a set of best practices for conducting participatory model assessments of other natural hazard and risk models intended to support decision-making.
Phenotypically similar but ecologically distinct: differences in competitive ability and predation risk among amphipods

Nature is often more diverse than expected with multiple species appearing to occupy the same niche. This observation is especially perplexing when the co-occurring species are cryptic (i.e. only distinguishable via molecular markers), because phenotypic similarity is expected to correspond with strong niche overlap. One way that phenotypically similar species can coexist is if fine-scale phenotypic differences affect how species interact with other members of the community that ultimately results in performance tradeoffs. An alternative explanation for co-occurrence is that phenotypic similarity leads to ecological equivalence allowing species to co-occur for long periods. We tested whether three phenotypically similar amphipod species that co-occur exhibit performance tradeoffs that may allow them to stably coexist in lakes. We found that despite their similarity the three species differed in how well they performed in competition with each other and their ability to avoid predation by fish and invertebrate predators. In some species comparisons, performance tradeoffs were apparent with species that perform well against heterospecifics performing poorly against predators and vice versa. We also found evidence for direct antagonistic interactions among amphipod species, in the form of wounding, which may play a role in structuring amphipod assemblages. Finally, the two species with the most similar phenotypes showed comparable responses to competitors and predators, which suggests that long-term co-occurrence via ecological equivalence may also be important in this system. Collectively, our results suggest that a mix of performance tradeoffs and ecological equivalence may allow for higher diversity than expected in amphipod assemblages.
ARFIMA approximation and forecasting of the limiting aggregate structure of long-memory process

This article studies Man and Tiao's (2006) low-order autoregressive fractionally integrated moving-average (ARFIMA) approximation to Tsai and Chan's (2005b) limiting aggregate structure of the long-memory process. In matching the autocorrelations, we demonstrate that the approximation works well, especially for larger d values. In computing autocorrelations over long lags for larger d value, using the exact formula one might encounter numerical problems. The use of the ARFIMA(0, d, d1) model provides a useful alternative to compute the autocorrelations as a really close approximation. In forecasting future aggregates, we demonstrate the close performance of using the ARFIMA(0, d, d1) model and the exact aggregate structure. In practice, this provides a justification for the use of a low-order ARFIMA model in predicting future aggregates of long-memory process. Copyright © 2008 John Wiley & Sons, Ltd.
DNS for Massive-Scale Command and Control

Attackers, in particular botnet controllers, use stealthy messaging systems to set up large-scale command and control. To systematically understand the potential capability of attackers, we investigate the feasibility of using domain name service (DNS) as a stealthy botnet command-and-control channel. We describe and quantitatively analyze several techniques that can be used to effectively hide malicious DNS activities at the network level. Our experimental evaluation makes use of a two-month-long 4.6-GB campus network data set and 1 million domain names obtained from >alexa.com. We conclude that the DNS-based stealthy command-and-control channel (in particular, the codeword mode) can be very powerful for attackers, showing the need for further research by defenders in this direction. The statistical analysis of DNS payload as a countermeasure has practical limitations inhibiting its large-scale deployment.
Leucine is a major regulator of muscle protein synthesis in neonates

Approximately 10% of infants born in the United States are of low birth weight. Growth failure during the neonatal period is a common occurrence in low birth weight infants due to their inability to tolerate full feeds, concerns about advancing protein supply, and high nutrient requirements for growth. An improved understanding of the nutritional regulation of growth during this critical period of postnatal growth is vital for the development of strategies to improve lean gain. Past studies with animal models have demonstrated that muscle protein synthesis is increased substantially following a meal and that this increase is due to the postprandial rise in amino acids as well as insulin. Both amino acids and insulin act independently to stimulate protein synthesis in a mammalian target of rapamycin-dependent manner. Further studies have elucidated that leucine, in particular, and its metabolites, α-ketoisocaproic acid and β-hydroxy-β-methylbutyrate, have unique anabolic properties. Supplementation with leucine, provided either parenterally or enterally, has been shown to enhance muscle protein synthesis in neonatal pigs, making it an ideal candidate for stimulating growth of low birth weight infants.
Mechanisms contributing to the arrhythmogenic influences of Alpha1-adrenergic stimulation in the ischemic heart

The majority of deaths associated with ischemic heart disease occur suddenly because of disturbances in cardiac rhythm culminating in ventricular fibrillation. Past research has focused on elucidating the biochemical membrane mechanisms responsible for the adverse electrophysiologic alterations in the ischemic heart, with major emphasis on the influence of adrenergic neural factors. It has been demonstrated that both alpha 1-and beta-adrenergic mechanisms contribute to arrhythmogenesis in the ischemic heart. In the normal heart, alpha 1-adrenergic input has very little effect on electrophysiologic indices. However, during early ischemia and reperfusion, enhanced alpha 1-adrenergic responsivity associated with a twofold reversible increase in alpha 1-adrenergic receptors in vivo has been demonstrated. Likewise, in a variety of species, alpha 1-adrenergic inhibition with prazosin markedly decreases the incidence of malignant ventricular arrhythmias associated with either myocardial ischemia or subsequent reperfusion. One major manifestation of alpha 1-adrenergic receptor activation during reperfusion of ischemic myocardium is an increase in intracellular calcium ion (Ca2+). It has been demonstrated that reperfusion of ischemic myocardium increases intracellular Ca2+ in reversibly injured tissue, and that the gain in intracellular Ca2+ is prevented by alpha 1-adrenergic inhibition with hydroxyphenylethyl aminomethyl tetralone, even when administered just prior to reperfusion. Subsequently, it was demonstrated that the alpha 1-adrenergic-induced increase in mitochondrial Ca2+ contributes to the decline in mitochondrial function. These findings suggest that even single-dose intervention with alpha 1-adrenergic inhibitors may improve markedly the functional recovery and extent of ultimate necrosis in humans after coronary thrombolysis. To investigate the mechanisms responsible for the increase in alpha 1-adrenergic receptors during ischemia, we used isolated adult canine ventricular myocytes exposed to hypoxia. Thirty minutes of hypoxia at 25 degrees C or 10 minutes of hypoxia at 37 degrees C resulted in a threefold reversible increase in the density of surface alpha 1-adrenergic receptors and a threefold increase in the cellular content of long-chain acylcarnitines. Inhibition of carnitine acyltransferase I abolished not only the accumulation of long-chain acylcarnitines during hypoxia but also the increase in alpha 1-adrenergic receptors. Exposure of normoxic myocytes to exogenous long-chain acylcarnitines (1 mumol/liter) for 10 minutes also increased alpha 1-adrenergic receptor number. These findings indicate that the sarcolemmal accumulation of long-cha
Advancing the Study of Decentralization and Federalism in Latin America

Bardhan, Pranab, and Dilip Mookherjee, eds. Decentralization and Local Governance in Developing Countries: A Comparative Perspective. Cambridge: MIT Press, 2006. Tables, figures, bibliography, index, 363 pp.; paperback $35. Diaz-Cayeros, Alberto. Federalism, Fiscal Authority, and Centralization in Latin America. New York: Cambridge University Press, 2006. Tables, figures, bibliography, index, 277 pp.; hardcover $80. Eaton, Kent. Politics Beyond the Capital: The Design of Subnational Institutions in South America. Stanford: Stanford University Press, 2004. Tables, bibliography, index, 267 pp.; hardcover $60. Gibson, Edward L., ed. Federalism and Democracy in Latin America. Baltimore: Johns Hopkins University Press, 2004. Tables, bibliography, index, 377 pp.; paperback $18.95. Wallack, Jessica S., and T. N. Srinivasan, eds. Federalism and Economic
Beyond black: celebrity and race in Obama's America

While not a stunning new idea, Beyond Black is well researched and engaging. It brings an array of scholars, pundits and critics of the Black entertainment elite into the conversation. With an ambi...
Mediation, Incremental Validity, and Novel Intervention Development: Introduction to a Special Issue on Youth Anxiety and Related Problems

Background The concepts of mediation and incremental validity are interrelated but this is often overlooked and underappreciated.
Orthogonality of modal bases in hp finite element models

In this paper, we exploit orthogonality of modal bases (SIAM J. Sci. Comput. 1999; 20:1671–1695) used in hp finite element models. We calculate entries of coefficient matrix analytically without using any numerical integration, which can be computationally very expensive. We use properties of Jacobi polynomials and recast the entries of the coefficient matrix so that they can be evaluated analytically. We implement this in the context of the least-squares finite element model although this procedure can be used in other finite element formulations. In this paper, we only develop analytical expressions for rectangular elements. Spectral convergence of the L2 least-squares functional is verified using exact solution of Kovasznay flow. Numerical results for transient flow over a backward-facing step are also presented. We also solve steady flow past a circular cylinder and show the reduction in computational cost using expressions developed herein. Copyright © 2007 John Wiley & Sons, Ltd.