cssi/SciSciGPT-SciSciNet huggingface dataset:
THE PREDICTIVE VALUE OF NECTAR CHEMISTRY TO THE RECOGNITION OF POLLINATOR TYPES

ABSTRACT The analysis of “nectar sugar ratios” shows a close relationship between the sucrose/(glucose + fructose) ratio and the type of pollinator that visits the flowers. When taken in conjunction with the morphology of the flowers and inflorescence, these ratios can be good predictors of the pollinators. Predictions are made for Erythrina crista-galli (Fabaceae), where its hexose-dominated nectar suggests passerine-bird pollination in contrast to species which are hummingbird-pollinated. Similarly, the genus Puya (Bromeliaceae) contains species with abundant sucrose in the nectar (hummingbird-pollinated species) and species with abundant hexose belonging to the massive monocarpie subgenus Puya. In P. raimondii, the hexose-dominated nectar and the inflorescence morphology suggest that it will be passerine-bird pollinated in the high Andes where it is native. Luehea speciosa (Tiliaceae), in the American tropics, has hexose-rich nectar and we predicted that it would be bat-pollinated. No bats were seen to...
An N-path implementation of a switched-capacitor inverter using charge transfer

The paper proposes an N-path implementation of a switched-capacitor inverter to drive a capacitive load. The need for such a driver stemmed from an ITS (intelligent transportation systems) project that requires efficient inverters for driving electroluminescent (EL) displays. The inverter has been designed to operate in the frequency range of 400 Hz - 1 KHz with peak amplitude of 100 V or more. The proposed inverter circuit employs a vertical siding approach where the sides have varying amplitudes to meet the stacking requirements of a sine wave. The method is suitable for the generation of any type of complex signals. The inverter's frequency stability and digital tunability, adjustability of its amplitude, and no use of magnetic elements are some of the advantageous features of the proposed system. The circuit operations, configurations, and experimental verifications of a 32-path system are presented in the paper
The Microworld of Diamonds: Images from Earth's Mantle

Figure 1. This 1.61-carat glassy diamond octahedron is a nearly perfect example of a gem-quality diamond crystal. All photomicrographs and macrographs by John I. Koivula Through the Eyes of the Inc...
Bravo! for the Power of Group Work with Kids (excerpt)

This brief statement is taken from the author’s comments at a conference on group work with children and youth held on October 29, 1999. It highlights the importance of peer group experiences in the development of self and the ability to relate to others, as well as the key role of committed adults who can help with this process.
Model-based controller for the automated tow-placement system

Model-based control in the manufacturing of advanced composite materials is one approach to improve the overall quality and performance of the final part. Frequently quantitative nondestructive methods are not available for feedback control, and therefore a predictive controller is required. This study investigates a neural network based control system for the automated thermoplastic composite tow-placement process. This non-autoclave process incorporates an advanced controller that predicts desired part quality at minimal cost. The control system combines a neural network (NN) based model, numerical and neural network optimization, as well as an infrared thermal image camera to sense the temperature profile on the part surface. The optimization utilizes the NN process model to calculate the optimum inputs for the desired quality, whereas the image camera is used for temperature feedback control.
Servant Leadership for Higher Education

AbstractThis essay reviews Wheeler’s (2012) book, essentially functioning as a handbook on servant leadership for academic leaders within higher education. Wheeler presents 10 principles of servant leadership that are important for deans, directors, and department chairs to consider when supervising faculty and staff, managing organizational dynamics, or setting a vision for the future. Wheeler’s insights, based on years of research on servant leadership, include practical ways to foster positive development of self, others, and organizations.
The Dignity of the South

The plaintiffs in Shelby County v. Holder argue that section 5 of the Voting Rights Act should be struck down because it offends the “equal dignity" of the covered states — an argument the Court appeared to credit in its last brush with section 5 in NAMUDNO. This Essay, written in advance of the decision in Shelby County, critically examines this equal dignity of the states argument and situates it in a larger context. Americans have been fighting for 150 years, since the Civil War and Reconstruction, about the structural implications of the events of 1861-70 for the sovereignty, dignity, and equality of the states — especially the Southern states. The implications of adopting the “equal dignity” of the covered states as a constraint on Congress’s Reconstruction Power are deeply problematic and profound.
Detection of thyroglobulin, thyroid peroxidase, and RET/PTC1 mRNA transcripts in the peripheral blood of patients with thyroid disease.

PURPOSEDetection of mRNA transcripts for thyroglobulin (TG), thyroid peroxidase (TPO) and RET/PTC1 in the peripheral blood of patients with thyroid disease.PATIENTS AND METHODSTG, TPO, and RET/PTC1 mRNA were analyzed in 52 peripheral-blood samples from 44 patients diagnosed with thyroid carcinoma (24 patients), adenoma (five patients), and nodular hyperplasia (15 patients) by reverse transcription-polymerase chain reaction (RT-PCR).RESULTSTG and TPO were identified in 13 patients (54.2%) with thyroid carcinoma, which includes five of eight patients with no clinical evidence of disease at the time of blood collection. Four of 5 patients had cervical lymph node metastases and/or extrathyroid extension at the time of the initial surgery. RET/PTC1 mRNA was detected in the peripheral blood of only one patient with papillary thyroid carcinoma. This sample was also positive for TG and TPO. TG and TPO were detected in two patients (10%) with benign thyroid nodules. All positive samples from patients with benign t...
Subcritical debonding of FRP-to-concrete bonded interface under synergistic effect of load, moisture, and temperature

Abstract External bonding of Fiber Reinforced Polymers (FRP) has played an important role in rehabilitation and retrofitting of aged reinforced concrete structures in the last two decades. However, the long-term durability of the FRP-to-concrete bonded interface is still an unresolved issue, which hampers the widespread use of these techniques. An environment-assisted subcritical debonding testing (EASD) program using a static wedge specimen is carried out in this study to evaluate the long-term durability of the FRP-to-concrete interface subjected to the synergistic effect of mechanical load, moisture, and temperature. Unlike commonly used critical debonding-based testing methods, EASD allows for interaction among mechanical load and environmental conditions (moisture and temperature), providing more insight into the degradation mechanisms of the interface between the concrete and the strengthening material. A commercially available coupling agent, γ-GPS was used to treat the concrete surface to improve the durability of the interface. This is because the coupling agent can introduce covalent bonds between the epoxy and concrete, which is much stronger than the hydrogen bonds formed between the epoxy and the concrete without coupling agents. Testing results shows that the moisture and temperature have significant effects on the subcritical debonding of the interface. A failure mode change from cohesive failure in the concrete in the air to the adhesive failure along the epoxy-concrete interface under aqueous condition was observed in the subcritical debonding of the FRP-to-concrete interface. EASD testing data confirms that the durability of the epoxy-concrete interface can be significantly enhanced by coupling agent treatment.
Balancing School With the Call to Community Service Hispanic Master's Students in U.S. Theological Schools

Hispanic seminary students in American theological schools face considerable challenges as they work to pursue their degrees. Many balance service to the ministry and community involvement with the rigors of academia. Cultural barriers leave students pulled between two worlds. Focus groups of Hispanic seminary students and data drawn from the Latino/a Seminary Student Survey were used to develop suggestions in providing more supportive and culturally sensitive curricula to attract and retain Hispanic students.
The Politics of Culture: Understanding Local Political Resistance to Detracking in Racially Mixed Schools.

In this article, Amy Stuart Wells and Irene Serna examine the political struggles associated with detracking reform. Drawing on their three-year study of ten racially and socioeconomically mixed schools that are implementing detracking reform, the authors take us beyond the school walls to better understand the broad social forces that influence detracking reform. They focus specifically on the role of elite parents and how their political and cultural capital enables them to influence and resist efforts to dismantle or lessen tracking in their children's schools. Wells and Serna identify four strategies employed by elite parents to undermine and co-opt reform initiatives designed to alter existing tracking structures. By framing elite parents' actions within the literature on elites and cultural capital, the authors provide a deeper understanding of the barriers educators face in their efforts to detrack schools.
Optimization of synthesis of a sulfonate hydrogen sulfide corrosion inhibitor

The inhibiting power of calcium alkylphenol sulfonate obtained by varying the ratios of the initial components was investigated with the optimization method. Using a method from mathematical statistics, the optimum values of the ratio of the basic reagents and conditions of synthesis of effective hydrogen-sulfide metal corrosion inhibitors were found.
Priests, Prelates, and Pastoral Ministry among Ethnic Mexicans: San Antonio, 1840-1940

Vincentian, diocesan, and Claretian priests served the predominantly ethnic Mexican congregation at San Fernando parish in San Antonio during the century following the political separation of Texas from the Mexican nation. Bishops also had frequent ministerial contact with parishioners, especially after 1874 when San Fernando became the cathedral of the newly-formed San Antonio diocese. All of these clergy shared common features in their ministries. Their view of ethnic Mexicans was consistently ambiguous: they highlighted their parishioners' strong devotional traditions, but also their perceived ignorance of the Catholic faith and their vulnerability to Protestant proselytizing efforts. They served Spanish-speaking parishioners in their native tongue in order to enhance the effectiveness of their ministries. They were unanimous in their derision of what they saw as the twin perils of Protestantism and the lax morals of contemporary society. Their antidote to these threats was instruction in Catholic faith and morals and active participation in the church's sacramental life, often promoted through involvement in pious societies and devotions. An exploration of their ministries illustrates the historical breadth of what today is called Hispanic ministry, as well as the mutual influence of clergy and ethnic Mexican laity on efforts to foster Catholic faith and religious traditions.
The sequence-activity relationship between metallo-β-lactamases IMP-1, IMP-6, and IMP-25 suggests an evolutionary adaptation to meropenem exposure

Metallo-β-lactamases are important determinants of antibacterial resistance. In this study, we investigate the sequence-activity relationship between the closely related enzymes IMP-1, IMP-6, and IMP-25. While IMP-1 is the more efficient enzyme across the overall spectrum of tested β-lactam antibacterial agents, IMP-6 and IMP-25 seem to have evolved to specifically inactivate the newer carbapenem meropenem. Molecular modeling indicates that the G235S mutation distinguishing IMP-25 from IMP-1 and IMP-6 may affect enzyme activity via Asn233.
NF-κB Activation Is Delayed in Mouse L929 Cells Infected with Interferon Suppressing, but Not Inducing, Vesicular Stomatitis Virus Strains

Vesicular stomatitis virus (VSV) mutant T1026R1 of the Indiana (IN) serotype is a good inducer of interferon (IFN). This mutant was used to study the activation of NF-kappaB, a transcription factor necessary for IFN induction, in mouse L929 cells that were stably transfected with a chimeric gene containing the human IFN-beta gene promoter attached to the chloramphenicol acetyltransferase (CAT) coding sequence. NF-kappaB DNA binding activity was detected as early as 30 min after virus adsorption in nuclear extracts, increased up to 4 hr, and then remained constant for at least 6 additional hr. The kinetics of CAT expression correlated with the kinetics of NF-kappaB nuclear DNA binding activity. Virus entry and delivery of viral components into the cytoplasm were required for NF-kappaB activation. Exposure of T1026R1 to one hit of UV irradiation nearly completely reduced NF-kappaB activation. In cells infected with wild-type (wt) VSV (IN), a noninducer of IFN, NF-kappaB DNA binding activity in the nucleus was delayed for several hours after virus adsorption. Coinfection of wt VSV and T1026R1 resulted in the reduction of T1026R1-promoted NF-kappaB activation. This inhibitory activity of wt VSV was abolished by one hit of UV irradiation. Under similar conditions expression of the CAT gene was more UV resistant, suggesting that IFN gene expression is regulated at multiple levels.
Analytical and Experimental Study of Wide Tuning Range mm-Wave CMOS LC-VCOs

The unprecedented interest in high bandwidth applications in the mm-wave range has set off a wave of research exploring techniques that enable wide tuning range voltage-controlled oscillators (VCOs). Low frequency CMOS LC-VCOs ( <;10 GHz) have been well studied in the literature and several approaches have been developed to optimize their performance. However, there lie several interesting challenges in the mm-wave space, specifically close to the fT/fmax, that motivate the need for analyzing the tuning range and phase noise in mm-wave VCOs. This paper presents a detailed analysis of the ultimate performance bound in simultaneously achieving low phase noise and wide tuning range in CMOS VCOs. The analysis is conducted on a 130 nm CMOS process, and confirmed by measurement results on three VCOs at 26 GHz, 34 GHz and 40 GHz. Finally, the impact of CMOS technology scaling (from 130 nm down to 45 nm), on the achievable performance bounds is analyzed and presented.
Ciliary neurotrophic factor is an axogenesis factor for retinal ganglion cells

Although mature mammalian retinal ganglion cells normally fail to regrow injured axons, exposure to the molecular environment of the peripheral nervous system stimulates regenerative growth. The present study used dissociated rat retinal ganglion cells purified by immunopanning to identify peripheral nervous system-derived factors that promote axonal outgrowth. Of the multiple growth factors investigated, only ciliary neurotrophic factor and the related cytokine, leukemia inhibitory factor, had striking neuritogenic activity, with half-maximal effects at 1-2 ng/ml. Brain-derived neurotrophic factor stimulated retinal ganglion cell survival nearly as well as ciliary neurotrophic factor, but had only minor effects on outgrowth. Thus, the neuritogenic effects of ciliary neurotrophic factor are not a simple consequence of increased survival. Ciliary neurotrophic factor-stimulated outgrowth was correlated with increased expression of the growth-associated membrane phosphoprotein, GAP-43, a hallmark of optic nerve regeneration in vivo. A high molecular weight fraction from media conditioned by rat optic or sciatic nerve mimicked the effect of ciliary neurotrophic factor in inducing axonal outgrowth. Ciliary neurotrophic factor was detected in the conditioned media on western blots, and the biological activity of the conditioned media was neutralized with an anti-ciliary neurotrophic factor antibody. These results indicate that ciliary neurotrophic factor has specific effects on axon outgrowth in retinal ganglion cells that are dissociable from its effects on cell survival, and that ciliary neurotrophic factor accounts for most of the axon-promoting activity for retinal ganglion cells present in either the sciatic or optic nerve.
Development and characterization of microsatellite markers for the poplar rust fungi Melampsora medusae and Melampsora larici-populina

Melampsora species and their hybrids are obligate parasites of Populus and Salix species worldwide. The increasing interest in Populus and Salix for biomass and fibre production necessitates genetic markers for population studies of Melampsora spp. Libraries enriched for simple sequence repeats were used to develop five microsatellite markers for Melampsora medusae and Melampsora larici-populina. The variation detected by these markers will be valuable for phylogenetic and population genetic studies, substantiate putative hybrids, and deployment of resistant poplar clones.
A Theory of the Quasi-Biennial Oscillation

Abstract A theory is presented which indicates that the quasi-biennial oscillation of the zonal wind in the tropical stratosphere is a result of the interaction of long-period, vertically propagating gravity waves with the zonal wind. We discuss the theoretical basis and observational evidence for the existence of long-period gravity waves near the equator, and the mechanism of their interaction with the zonal wind, and present some simple numerical results which show how the absorption of the momentum of these waves by the mean flow leads to a downward propagating zonal wind profile. It is shown that the interaction of these gravity waves with the observed semiannual zonal wind oscillation above 40 km will produce a downward propagating quasi-biennial oscillation. We present the results of several numerical experiments with a model of the tropical stratosphere which includes the gravity wave interaction mechanism. The quasi-biennial oscillation is simulated quite successfully. Finally, we discuss possibl...
Imaging of ceramic liner fractures in total hip arthroplasty: the value of CT

Fracture of a ceramic liner of a total hip arthroplasty is rare and is radiographically occult if not displaced. We report on two patients in whom ceramic liner fracture was radiographically occult but was diagnosed on subsequent CT scan through appropriate windowing.
On circuit exchange properties for matroids

Fournier has characterized binary materials in terms of a certain circuit exchange property. This paper examines several related circuit exchange properties and gives excluded-minor characterizations of the matroids having these properties.
Towards a molecular therapy for glycogen storage disease type II (Pompe disease)

Glycogen storage disease type II (GSD-II), also known as Pompe disease, is a fatal genetic muscle disorder caused by a deficiency of acid a-glucosidase, a glycogen-degrading lysosomal enzyme. Currently, there is no treatment for this fatal disorder. However, several lines of research suggest the possibility of future treatment. Enzyme replacement strategies hold the greatest hope for patients currently affected by GSD-II, but future strategies could include in vivo or ex vivo gene therapy approaches and/or mesenchymal stem cell or bone-marrow transplantation approaches. Each of the approaches might eventually be combined to further improve the overall clinical efficacy of any one treatment regimen. The lessons learned from GSD-II research will also benefit a great number of individuals affected by other genetic disorders.
Does excessive buying for self relate to spending on pets

Abstract Using two studies, this article explores how a tendency to buy excessively for self relates to spending on one's pet. Existing research on excessive buying reports that these buyers spend money primarily on themselves. Excessive buying is the tendency to be preoccupied with buying and, consequently, to buy relatively more and more often than others. The first study, using a qualitative research approach, provides insights into the relationship of excessive buying for self and for pets. This study reveals that excessive buyers consider their pets as full family members and extensions of themselves. The second study, a national survey conducted via the Internet, provides a quantitative test of the relationship between excessive buying for self and spending on pets. Respondents who score high on an excessive buying index also tend to spend more on their pets for toys, food treats, clothing, accessories, and grooming products.
Principals' Influence on Academic Achievement: The Student Perspective

Research identifying relationships between principals' instructional leadership behavior and academic achievement is problematic because it fails to consider the perspectives of the “consumer” (i.e...
Modification of 4-thiouridine and phenylalanine transfer RNA with parachlormercuribenzoate.

Abstract While investigating the modification of the 4-thiouridine moiety in E. coli tRNAPhe with parachloromercuribenzoate with a view to further elucidate the biochemical function of the minor base and prepare tRNA labeled with a heavy metal at a specific site for X-ray crystallography, we observed that the paramercuribenzoate moiety in the modified tRNAPhe is very labile in the presence of Mg2+. Surprisingly this lability is not observed at the mononucleoside level when the reaction is carried out with the mercurated derivatives of 4-thiouridine or its methyl analog. Evidences for 1:1 stoichiometry of the reaction of parachloromercuribenzoate with 4-thiouridine and for the covalent nature of the HgS bond in the mercurated nucleoside have been obtained by carrying out the reaction with N1-methyl-4-thiouracil and isolating and characterizing the product, 1-methyl-4-thiouracilylparamercuribenzoic acid.
Teaching, research, and service: Expectations of assistant professors

In this article, we critically evaluate the expectations of assistant professors as perceived by junior and senior faculty (n=22) across seven disciplines at two universities. Our research shows that there are similarities and differences within Sociology departments, across disciplines, and across the teaching and research schools where we collected our data. In one respect, Sociology is no different than the other departments where we interviewed faculty members—ambiguity abounds in terms of expectations for junior faculty. Scholarship expectations for tenure and promotion to associate professor vary much more greatly across rank, discipline, and institution than do those for teaching or service. Based on our findings, we offer several suggestions for improving the transition to the role of Assistant Professor in Sociology. Our suggestions focus on change within graduate programs, hiring institutions, and Sociology as a discipline. While our results are consistent with prior research in many cases, we note that the generalizability of our findings is limited given the number of interviews conducted and the purposive sampling design utilized. However, we hope that our results will provide additional information that may help others as they prepare to begin their roles as assistant professors.
The second battle of Battle Creek — the open shop movement in the early twentieth century

(1973). The second battle of Battle Creek — the open shop movement in the early twentieth century. Labor History: Vol. 14, No. 3, pp. 323-339.
A decision making model: Its structure and form

I explain the logic and real‐time track record of the expected utility model used for forecasting the outcome and dynamics of political choices. The model represents an example of applied modeling....
Medroxyprogesterone acetate in the treatment of renal cell carcinoma (hypernephroma).

Medroxyprogesterone acetate, a potent synthetic progestational steroid, was administered to 23 patients with metastatic renal cell carcinoma. Seven patients received 300 mg/d orally. Six patients received 100 mg/d intramuscularly of the commercial preparation Provera. Ten patients were given 400 mg/w intramuscularly of an investigational preparation. Twenty-one patients completed a minimum treatment period of 6 weeks and were considered evaluable. There were one complete and two partial objective remissions to the parenteral preparations. No responses were observed with the oral preparation. The dose to response varied from 5.2 to 9.0 Gm and the duration of response from 4 to 30+ months. There did not appear to be a correlation of response with age, duration of disease, or histologic grade or cell type. A “symptom status” indicating severe disability from disease did adversely affect response. Minimal side effects were weakness in two patients, loss of libido in one male patient and minimal signs of virilism in one female patient. Eleven patients who showed progressive disease after an adequate trial of medroxyprogesterone acetate received further treatment with testosterone. There was one partial objective response of 5 months' duration. These results are superior to those obtained with chemotherapy.
Thermal Analysis of Encapsulated Phase Change Materials for Energy Storage

Concentrating solar power technology is recognized as an attractive option for solar power. A major limitation however is that solar power is available for only about 2,000 hours a year in many places. Therefore it is critical to find ways to store solar thermal energy for the off hours and it is better to store the energy at high temperatures. The present work deals with certain aspects of storing solar thermal energy at high temperatures with phase change materials (PCM) in the range of 275°C to 425°C. NaNO3 is selected as a phase change material encapsulated by stainless steel. The objective is the storage of hundreds mega-watt-hours equivalent of solar energy in systems using encapsulated phase change materials (EPCM). Numerical predictions of conduction and phase change processes are reported here in the form of transient temperature profiles in the PCM and encapsulation materials of EPCM capsules for convective boundary conditions outside EPCM. The time for heating and melting during charging (storage of thermal energy into encapsulated phase change material) and the time for cooling and solidification during discharging (discharge/retrieval of thermal energy) are predicted for NaNO3 PCM in encapsulation. For a temperature range of about 125°C around melting/freezing temperature of the PCM the time it takes to melt/freeze the PCM during storage/retrieval is much longer than the time it takes for diffusion (sensible heat) storage alone. Depending on the properties of the PCM, the energy associated with the latent heat of melting can be a significant leading to smaller thermal energy storage systems and lower costs. As can be expected, the time for heat transfer is much shorter for liquid heat transfer fluids compared to those for gaseous heat transfer fluids that transport the energy to the EPCM.Copyright © 2011 by ASME
Research on positive and negative social behavior

"Positive" and "negative" social behavior was defined, and the key words in 3353 studies abstracted in the Psychological Indexes and Abstracts for the decades 1900-1975 were categorized accordingly. Studies were also categorized for their methodological orientation, and whether they used animals, children, or adults as subjects. Results: (a) prior to about 1920, there was little difference between the number of positively and negatively marked studies, (b) since about 1920 there have been more negative than positive social behavior studies, (c) recently there has been a significant increase in positively designated studies, (d) among the latter there has been an increase in experimental and psychotherapy studies using adult human subjects. These results are discussed in terms of certain influences upon research during this period, and the broadening of behavioral sciences theories.
Protein Reserves in the Lactating Dairy Cow

Abstract Protein reserves were measured in a nitrogen depletion-repletion experiment with 15 lactating Holstein cows. At 2 to 3 wk postpartum, cows were fed 14 kg/day of a ration containing 9% crude protein (dry matter). At the end of depletion (8 to 16 wk), animals were assigned randomly to rations containing 14, 18, or 22% crude protein. The amount of nitrogen repleted was measured by nitrogen balance. The animals were fed a complete ration of 60% corn silage and 40% concentrate dry matter. Intake was greater for the 14 and 18% protein groups during repletion. Milk production was greater for the 18% group, 26.5 kg/day compared with 22.8 and 21.9 kg/day for the 14 and 22% protein groups. Nitrogen balance was affected by protein content of the ration. Means were .24, .43, and .60g nitrogen per day per kg body weight 75 . Urinary nitrogen increased with crude protein; however, fecal nitrogen was not affected. Milk nitrogen output was greater for the 18% group. Apparent means of digestibilities for dry matter and nitrogen were 62.0 and 63.0 for the 14% group, 64.3 and 71.7 for the 18% group, and 67.1 and 75.1 for the 22% group. The groups were repleted for a period of 12.4, 9.6, and 7.4 wk and accumulated 19.7, 29.2, and 31.7g nitrogen per kg body weight 75 . There was a greater amount of nitrogen repleted by the medium and high groups compared with the low-protein group. On a live weight basis, the treatment groups repleted an estimated 16.7, 25.1, and 27.1% of total body nitrogen.
Factional Competition, Sociopolitical Development, and Settlement Cycling in Ìlàrè District (ca. 1200-1900): Oral Traditions of Historical Experience in a Yorùbà Community

This paper is an assessment of the local historical model of sociopolitical development and settlement history in Ilare community, southwest Nigeria. Ilare was at the nucleus of an early sociopolitical formation in Ijesaland. The formation, known as Eka Osun, held sway over the area of northern Ijesaland between the thirteenth and sixteenth centuries. The study forms part of the ongoing archeological and historical investigations on the settlement history and regional interactions in central Yorubaland.The episodes of settlement cycling are the hallmarks around which the historical experiences of Ilare are organized. In other words, the trajectories of Ilare's historical experience parallel the shifts in its settlement location (habitus). Moreover, the oral traditions stress intersocietal conflict and intergroup alliance as the important factors in the earliest sociopolitical transformations in northern Ijesaland. The traditions also highlight how factional competitions resulted in the continuous shift in the settlement of Ilare within an area of about eight kilometers in diameter over an 800-year period. The oral historical narratives not only draw on kinship idioms in the construction of hierarchical social relations, but the narratives also emphasize intercommunity relations as the plot of historical experience and social actions.The attempt here is to outline the historical trajectories of events that heralded Ilare as the political center and that characterized its transformations to a political periphery in northern Ijesaland. This study also historicizes the long-term patterns of relationship between factional competition and regional inter-community relations on the one hand and sociopolitical development and settlement cycling on the other.
Water Tank Study of the Decay of Trailing Vortices

Underwater towing experiments were carried out with a rectangular airfoil of aspect ratio 5.3 at 4° and 8° angles of attack and at chord-based Reynolds numbers between 2.2 x 10 5 and 7.5 x 10 5. Tangential velocity measurements in the downstream region between 100 and 1000 chord lengths indicate rates of vortex decay proportional to r 7/8 at 8°, whereas previous flight tests show that the decay rate approaches £~ 1/2 far downstream. The observed behavior is explained in terms of an analytical solution that includes time dependence of the turbulent eddy viscosity, VT ~ tm. It shows that, for m > 0, an isolated turbulent vortex decays faster than t~1/2. In this case, the decay is accompanied by increasing vr, or levels of turbulence, which corresponds to turbulent nonequilibrium flow. The special case of vortex decay with equilibrium flow (m = 0) leads to the well-known decay rate 2. Since, in towing tank experiments at low Reynolds number, turbulent vortex decay may occur predominantly in nonequilibrium, it is doubtful that such tests correctly predict the late stage of decay of aircraft trailing vortices, when turbulence is the only dissipating mechanism.
The Light Buffer: A Shadow-Testing Accelerator

In one area of computer graphics, realistic image synthesis, the ultimate goal is to produce a picture indistinguishable from a photograph of a real environment. A particularly powerful technique for simulating light reflection-an important element in creating this realism-is called ray tracing. This method produces images of excellent quality, but suffers from lengthy computation time that limits its practical use. This article presents a new method to reduce shadow testing time during ray tracing. The technique involves generating light buffers, each of which partition the environment with respect to an individual light source. These partition descriptions are then used during shadow testing to quickly determine a small subset of objects that may have to be tested for intersection. The results of timing tests illustrate the beneficial performance of these techniques. The tests compare the standard ray-tracing algorithm to light buffers of varying resolution.
Enterobactin Protonation and Iron Release: Hexadentate Tris-Salicylate Ligands as Models for Triprotonated Ferric Enterobactin1

Enterobactin mediates iron uptake in Escherichia coli and related bacteria. The structure of the neutral protonated ferric enterobactin complex Fe[H3enterobactin] has been the source of some controversy in the literature. The coordination chemistry of the new model ligands tris[(2-hydroxybenzoyl)-2-aminoethyl]amine (TRENSAM) and tris[(2-hydroxy-3-methoxybenzoyl)-2-aminoethyl]amine (TREN(3M)SAM) demonstrate the previously proposed tris-salicylate mode of binding for ferric enterobactin; they form 1:1 metal−ligand complexes with Fe3+ and Al3+ that bind the metals through tris-salicylato coordination (i.e., the chelate is a six-membered metallocycle with the phenolic and amide oxygens binding the metal center). The ferric and aluminum complexes of TRENSAM are isostructural and crystallize in the monoclinic space group P21/c. The ferric and aluminum complexes of TREN(3M)SAM are nearly isostructural and crystallize in the triclinic space group P1, with the same salicylate mode of bonding as the TRENSAM comple...
The New Madrid Seismic Zone: not dead yet.

The extent to which ongoing seismicity in intraplate regions represents long-lived aftershock activity is unclear. We examined historical and instrumental seismicity in the New Madrid central U.S. region to determine whether present-day seismicity is composed predominantly of aftershocks of the 1811–1812 earthquake sequence. High aftershock productivity is required both to match the observation of multiple mainshocks and to explain the modern level of activity as aftershocks; synthetic sequences consistent with these observations substantially overpredict the number of events of magnitude ≥ 6 that were observed in the past 200 years. Our results imply that ongoing background seismicity in the New Madrid region is driven by ongoing strain accrual processes and that, despite low deformation rates, seismic activity in the zone is not decaying with time.
A nearest neighbor sweep circle algorithm for computing discrete Voronoi tessellations

An algorithm for computing discrete, 2-dimensional, Euclidean Voronoi tessellations is presented. The algorithm combines a limiting sweep circle approach with a nearest neighbor cellular approach. It reduces the computational cost of the naive approach while at the same time giving the Euclidean Voronoi tessellations that simple nearest neighbor algorithms are unable to produce. The algorithm is shown, through analytical methods, to produce good approximations to corresponding continuous Voronoi tessellations depending on the definition of neighbor used in the nearest neighbor step and the mesh size. The quality of different types of neighbor definitions are discussed as well as the computational cost. The algorithm is general enough to be easily extended to higher dimensions and nonuniform meshes. The analysis lays the groundwork for the computation of discrete centroidal Voronoi tessellations where some kind of numerical integration is required.
Characterization and formation of polygonal fractures on Venus

[1] Fracture theory predicts that polygonal cracks will form in the presence of an isotropic, extensional stress field. On Venus, polygonal fractures are observed on scales several orders of magnitude larger than on Earth, with an average diameter of 1.8 ± 0.9 km. Proposed formation mechanisms include cooling following lava flow emplacement, lithospheric heating, and climate change. Here we examine the characteristics and geologic setting of 204 regions of polygons. Some regions display two spatially overlapping size ranges, with the larger spacing typically 10–25 km. Most polygonal fractures appear to be extensional, but some have the morphology of compressional ridges. Polygons are confined to plains regions and occur in association with shield fields (49%), coronae and coronae-like features (21.3%), tessera (17.5%), and wrinkle ridges (20%). In locations where polygons occur with shield fields, coronae, or both, they appear to have formed contemporaneously. Formation in conjunction with local heating events is consistent with the lithospheric cooling hypothesis. However, there is almost never the predicted decrease in size away from the center of coronae or shield fields. Only a small percentage of coronae and shield fields contain polygons, indicating that they are not typical of the formation process. The climate change-induced scenario is consistent with many characteristics of the polygons, including the small and large size ranges, the compressional ridges, and their occurrence with and without evidence of local heating. Although polygons may have diverse origins, including formation by multiple deformation events, overall polygon characteristics support the climate change hypothesis.
Differential migration of astrocytes grafted into the developing rat brain.

Fetal and neonatal astrocytes migrate in specific patterns when transplanted into the adult rat host brain. However, it is unclear whether these astrocytes demonstrate the same degree of mobility during early brain development. In the present study, neonatal cortical, hippocampal, and hypothalamic astrocytes were collected from the brains of 1- to 3-day-old rats and placed in tissue culture. After 14 to 21 days, cultures enriched in astrocytes were harvested and labelled with either the fluorescent dye Fast Blue or fluorescein-labelled latex beads. They were then transplanted into the right frontal cerebrum of neonatal rats at 2,5,8, and 11 days postpartum. Seven days after transplantation, animals were sacrificed and their brains were fixed by immersion in aldehydes, sectioned on a cryostat, and examined with fluorescence microscopy. Transplanted astrocytes migrated along the corpus callosum, internal capsule, glial limitans, ventricular linings, and hippocampal structure. Labelled cells were also found in the contralateral hemisphere in day 2 brains. Migration in a radial fashion from the injection site toward the periphery was a particularly obvious pattern, and was most pronounced in these younger hosts. In days 5 and 8 rat brains, astrocyte migration became more restricted to the hemisphere of implantation. In 11-day-old host brains hemispheric restriction and other region-specific influences became manifest and specifically modulated migration. Radial migration was absent in the 11-day-old host group except for cells of cortical origin. The observed results demonstrate that neonatal cortical, hippocampal, and hypothalamic astrocytes transplanted into the neonatal cerebrum migrate in patterns that are more extensive than in the adult brain. This suggests that cellular migration in the neonatal brain is governed by factors that are less restrictive than those regulating migration in the adult brain. In particulur, our observations imply that radial glia may provide migratory substrates for transplanted astrocytes, and region-specific regulation of migration may begin around 11 days after birth. © 1993 Wiley-Liss, Inc.
Review of Duchenne Muscular Dystrophy (DMD) for the Pediatricians in the Community

Duchenne muscular dystrophy (DMD), an inherited X-linked recessive disorder, is characterized by progressive symmetric muscle weakness and gait disturbance, with onset in early childhood. DMD is the most common muscular dystrophy in children, and incidence ranges from 1 in 3600 to 4700 live male births. Early diagnosis (screening, confirmation, and genetic counseling), treatment, and long-term follow-up of affected individuals in routine pediatric practice can be challenging and are the focus of this review.
Kinetic study of semifluorinated arylene vinylene ether polymers

Fluorinated arylene vinylene ether (FAVE) polymers were prepared from the base-promoted addition of commercial 2,2-bis(4-hydroxyphenyl)hexafluoropropane (6F bisphenol A) to aryl trifluorovinyl ether (TFVE), 2,2′-bis(4-trifluorovinyloxybiphenyl)-1,1,1,3,3,3-hexafluoropropane. The step-growth polymerization kinetics by using stoichiometric NaH and catalytic Cs2CO3 were investigated by monitoring the 19F NMR signals of the aryl TFVEs. The nth order kinetic model was used to determine rate constants over a series of programmed temperatures. Polymerization using stoichiometric NaH resulted in second-order kinetics with an activation energy of 59 kJ/mol. This model kinetic study provided insight into the mechanistic pathways of the FAVE polymer system that has recently shown a lot of interest in many areas of materials science. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
The Role of the Organization of American States in Conflict Prevention

First of all, I would like to sincerely thank the Ministry for Foreign Affairs of Sweden and the Raoul Wallenberg Institute of Human Rights and Humanitarian Law for the opportunity to speak with you today about the role of the Organization of American States in conflict prevention. I would also like to congratulate both institutions for the undertaking of this event.
Dielectric Constant of a Semiconductor in an External Electric Field

The effect of a constant external electric field on the transverse dielectric constant of a semiconductor is calculated. The field produces a sharp decrease in the dielectric constant close to the threshold for an interband transition. Above the edge, the behavior is oscillatory. Numerical results have been obtained for gallium arsenide.
Deuterium exchange mass spectrometry as a probe of protein kinase activation. Analysis of wild-type and constitutively active mutants of MAP kinase kinase-1.

Wild-type and constitutively active mutants of human MAP kinase kinase-1 (MKK1) were analyzed by deuterium exchange mass spectrometry using a protocol that minimized loss of deuterium during analysis due to back exchange. The observed peptides accounted for 335 out of 393 residues. Not counting overlap peptides, three peptides showed decreased exchange in constitutively active compared to wild-type MKK1 and nine showed increased exchange. Backbone amides in which exchange rates decreased upon kinase activation were observed near the regulatory phosphorylation sites Ser218 and Ser222 and the adjacent β9 strand. These decreases are consistent with electrostriction or reduced solvent access due to domain closure or formation of new hydrogen or salt bonds around the catalytic cleft and within the activation lip. Increased exchange upon activation was observed within six peptides derived from helix C and the five-stranded β sheet from the N-proximal lobe of the conserved kinase domain and in one peptide locate...
Aortic and extracranial large vessel giant cell arteritis: A review of 72 cases with histopathologic documentation

Abstract Giant cell arteritis (GCA) is closely identified with the temporal arteritis-polymyalgiarheumatica syndrome of the elderly. It is also a systemic disease that can cripple and kill. Up to 15% of patients with temporal arteritis may have angiographic evidence of extracranial GCA, and aortic insufficiency, ruptured aortic aneurysm, aortic dissection, stroke, or myocardial infarction may be the initial manifestation of systemic GCA. A review of 72 cases of aortic and extracranial GCA, all with histopathologic verification of the disease, revealed that 25% of patients with aortic and extracranial large-vessel GCA had asymptomatic temporal arteritis; the ascending aorta and aortic arch were most frequently involved (39%), followed by the subclavian and axillary arteries (26%), and the femoropopliteal arteries (18%). Nine patients (12.5%) underwent an upper or lower limb amputation. Of the 18 patients whose death was directly attributable to extracranial GCA the causes were ruptured aortic aneurysm (6), aortic dissection (6), stroke (3), and myocardial infarction (3). The findings of these 72 cases caution against attributing all aortic and large-vessel arterial disease in the elderly to atherosclerosis and emphasize that timely surgical intervention may be necessary for life-saving and limb-salvage in patients with aortic and extracranial GCA.
An experimental study of backgating effects in GaAs MESFETs

Abstract This paper presents the results of a series of experiments concerning the backgating effect in GaAs MESFETs, and high-field current behavior of backgate diode structures. The devices tested were selectively ion-implanted and mesa-etched structures fabricated on semi-insulating (SI) undoped and Cr-doped LEC substrates. These experiments were performed to separate the effects of the substrate bias and the backgate bias and to identify the carrier emission processes using bias variations and optical excitations. The main objective was to determine the effects of surface condition by comparing the behaviors of devices with untreated and nitride-a and Al-deposited SI surfaces. A model for the backgating effect is proposed that involves trapping of electrons near the surface in the backgate structure, and space charge build-up beneath the MESFET channel region by deep-level trapping and free-carrier distribution. The temperature dependence of the backgating high-field current suggests that surface trapping by shallow levels is often significant and this causes the backgating threshold voltage to increase rather rapidly, as the temperature is lowered.