cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis and thermal and spectroscopic properties of macrocyclic vinyl aromatic polymers

Well-defined and narrow molecular weight distribution macrocyclic poly(2-vinylnaphthalene) (P2VN) and poly(2-vinyl-9,9-dimethylfluorene) (PDMVF) containing a single 1,4-benzylidene or 9,10-anthracenylidene unit have been synthesized via the potassium naphthalide initiated polymerization of the monomers followed by the end-to-end coupling of the resulting P2VN dianions under high-dilution conditions with 1,4-bis(bromomethyl)benzene or 9,10-bis(chloromethyl)anthracene. Molecular characterization has been carried out by size exclusion chromatography, nuclear magnetic resonance, differential scanning calorimetry, ultraviolet–visible spectroscopy, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The thermal properties show distinct differences between the cyclic and matching linear polymers, with the macrocycles showing much higher glass-transition and decomposition temperatures. The absorption bands are both hyperchromic and hypochromic with respect to the model aromatic compounds, and this is consistent with intensity borrowing. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5488–5503, 2004
The roles of pathways in the spinal cord lateral and dorsal funiculi in signaling nociceptive somatic and visceral stimuli in rats.

The spinothalamic tract (STT) is a major ascending nociceptive pathway, interruption of which by cordotomy is used for pain relief, whereas the dorsal column (DC) pathway is usually not considered to be involved in pain transmission. However, recent clinical studies showed good relief of visceral pain in cancer patients after a DC lesion. Electrophysiological recordings in animals suggest that the analgesic effect is due to interruption of axons ascending from postsynaptic dorsal column (PSDC) neurons located in the vicinity of the central canal. In this behavioral study, we used a decrease in exploratory activity in rats after a noxious stimulus as an indicator of perceived pain, independent of withdrawal reflexes. Intradermal capsaicin injection almost abolished exploratory activity in naive animals or in rats after a DC lesion, but did not change it in rats after ipsilateral dorsal rhizotomy or a lesion of the lateral funiculus on the side opposite to the injection. In contrast, a bilateral DC lesion counteracted the decrease in exploratory activity induced by noxious visceral stimuli for at least 180 days after the surgery. Although neurons projecting in both the STT and the PSDC path can be activated by noxious stimuli of cutaneous or visceral origin, our results suggest that the STT plays a crucial role in the perception of acute cutaneous pain and that the DC pathway is important for transmission of visceral pain.
Normal, resonance enhanced, and surface enhanced Raman spectra of ruthenium pyridyl complexes

Abstract Normal Raman (NR) spectra of solid and solution phase 2,2′-bipyridine and solid phase Ru(bpy)(PVP)(ClO 4 ) 2 are shown. Resonance Raman (RR) spectra of solid and solution phase Ru(bpy)(pyr) 4 (ClO 4 ) 2 and Ru(pyr) 6 (BF 4 ) 2 are presented. Surface-enhanced Raman (SER) spectra of 2,2′-bipyridine, Ru(bpy)(pyr) 4 (ClO 4 ) 2 , (Ru(pyr) 6 (BF 4 ) 2 , and Ru(bpy)(PVP)(ClO 4 ) 2 at silver electrodes are presented. Above, pyr=pyridine, bpy-2,2′-bipyridine, and PVP=poly(4-vinylpyridine). The effect of elctrode potential on the SER spectra of these compounds is shown by spectra acquired at applied potentials from 0.0 to −1.0 V, and plots of SER intensity vs. electrode potential. Excitation profiles for selected bands of each compound are presented. Comparison of SER spectra of Ru(bpy)(pyr) 4 (ClO 4 ) 2 and polymeric Ru(bpy)(PVP)(ClO 4 ) 2 suggests no potential effect intrinsic to the SER mechanism. Plots of SER intensity vs. electrode potential show the SER effect is dependent on the individual surface-active species. SER excitation spectra for these compounds show that colored ruthenium complexes exhibit a maximum with respect to excitation wavelength. The SER maxima are shifted toward longer wavelengths in comparison with the known UV-vis solution absorbance maxima.
Lanthanide-ion modified cyclodextrin supramolecules

Abstract A cyclodextrin appended with a lanthanide-ion macrocycle comprises a microscopic bucket that lights up when filled with mono- and bicyclic aromatics. This triggered luminescence response arises from an absorption-energy transfer-emission (AETE) process where blue light, absorbed by the aromatic, is transferred to the lanthanide ion to produce the emitting 5 D 0 excited state of Eu 3+ or the 5 D 4 excited state of Tb 3+ ion. Three supramolecule systems are presented, focusing on the design features that lead to the best luminescence response.
CLINICAL STUDIES OF THYROGONADAL CORRELATES. II. BASAL METABOLIC RATES AND SEMINAL FINDINGS1

PRELIMINARY CONSIDERATIONS of the preceding article have set forth the advisability of studying the thyro-gonadal interrelationships in the male. Both the endocrine and exocrine (gametokinetic) functions of the male gonads merit investigation under the conditions of varying grades of thyroid activity. The present study deals with correlations of basal metabolic rates and seminal biometry and cytology. At the present, any investigations of speratogenic functions to a great degree are unsatisfactory because of our deficient knowledge of the normal physiology of spermatozoa. Hartman's recent review (1) takes critical inventory of this knowledge. While fairly well accepted standards of normalcy are recognized for numbers and dilution of spermatozoa, cytologic characteristics, degree of and duration of motility of spermatozoa and volumes of ejaculates, there is little critical information upon the various factors which may influence these. Segregation of single causal variants in comparative studies of seminal...
Central nicotinic receptor ligands and pharmacophores.

Abstract Multiple populations of pentameric nicotinic acetylcholinergic (nACh) receptors exist and several may be classified as central or neuronal. Neuronal nACh receptors, however, are primarily of the α4β2 and α7 types, and these have been the focus of most recent investigations aimed at the development of novel agents and identification of pharmacophores. Selectivity data are limited. Furthermore, because several populations of nACh receptors might indirectly influence a given functional effect, it is difficult to discuss structure-activity relationships (SAR) in terms of differential SAR, or to formulate SAR on the basis of functional studies. For the most part, studies are limited to the formulation of structure-affinity relationships (SAFIR) for the binding of agents at nACh receptors, and for these the α4β2 population has been the most extensively investigated. SAFIR and newer agents are reviewed here with reference to earlier studies. Novel agents now have been identified that bind with up to 30 times higher affinity than nicotine and these are providing new insight into the understanding of nACh receptors.
Selecting the "Best Applicant(s)" with Limited Options and Policy Constraints.

This case study examines issues related to teacher hiring and accountability policies, including the adequate yearly progress and highly qualified teacher provisions of the No Child Left Behind act. The focus of the case study is the nexus among findings from the teacher-quality research, realities of teacher labor markets, and accountability policies. Opportunities for discussion of leadership decisions at the school and district levels are provided. The details described in this case study are developed for use in personnel/instructional supervision courses.
Minimal Effects of Acrylonitrile on Pulmonary and Hepatic Cell Injury Enzymes in Rats with Induced Cytochrome P450

Acrylonitrile (AN) has many industrial applications but is a known carcinogen in animals and a suspect human carcinogen. Its toxicity is generally associated with its bioactivation, the initial step of which is epoxidation by cytochrome P450. While the hepatotoxicity and pneumotoxicity of AN in naive rats is generally low, the purpose of this study was to investigate the pneumotoxicity and hepatotoxicity of AN in adult male Sprague-Dawley rats and evaluate interactions with agents that may alter its metabolism. Five agents, phenobarbital, beta-naphthoflavone, pyridine, ethanol, and acetone, were administered prior to AN as inducers of CYP2B, CYP1A, and CYP2E1. Pneumotoxicity was measured as increases in y-glutamyltranspeptidase (GGT) and lactate dehydrogenase (LDH) in bronchoalveolar lavage fluid (BALF). Hepatotoxicity was measured as increases in serum sorbitol dehydrogenase (SDH). AN (1 mmol/kg ip) had little effect on liver or lung, even when given following most of the inducing agents. AN (1.5 mmol/kg) caused an increase in GGT, but had little effect on SDH or LDH. Acetone plus AN caused an increase in mortality and some indication of pneumotoxicity, but lung and liver were histologically normal. Thus AN alone even at a high dose had no effect on the liver or lung and minimal effects following induction of cytochrome P450 by acetone.
THIAMINE UPTAKE BY HUMAN FIBROBLASTS

Thiamine requiring enzymes are commonly studied in cultured fibroblasts but the mechanism of thiamine accumulation had not been defined in these cells. Thiamine is concentrated greater than in the medium by 30-60 minutes and reaches apparent concentrations 6 times the medium by 2-3 hours. Kinetic studies demonstrate that uptake is saturable and the apparent Km(.15-3 μM) and Vmax (.6-.8 p moles/mg/min) are similar to those in gut and brain. However, the uptake process is quite different. Accumulation is highly specific but not energy dependent. Before thiamine is phosphorylated it is bound to at least two <40,000 MW cytoplasmic proteins. Uptake and binding are competitively inhibited by pyrithiamin but only slightly by TP or TPP. Thiamine efflux is biphasic with rapid efflux occuring over 30-60 minutes followed by a slow phase lasting at least several hours, probably reflecting phosphorylation. We conclude that thiamine uptake in these cells is more comparable to steroid hormone uptake than to thiamine uptake by specialized transport tissue.
Then and Now: Regionalism in American Sociology, 1937–1962*

(1962). Then and Now: Regionalism in American Sociology, 1937–1962. The Sociological Quarterly: Vol. 3, No. 4, pp. 278-285.
The Evergreen Story of Psammetichus’ Inquiry into the Origin of Language

Herodotus recounts the attempt of the pharaoh Psammetichus I to determine which among the peoples of the earth was the oldest. He isolated two children at birth, assuming that their spontaneous speech would reveal the identity of a primordial human language. Although Psammetichus’ inquiry was not explicitly designed to address linguistic issues, it has long been passed down in western reflection on language. This article reviews some of the most significant roles that the story of Psammetichus has played. The story was abundantly cited in 16th-century literature that conceptualized a first human language. It has also contributed to debate about the origin of language, especially during the mid–19th century. Moreover, the story of Psammetichus’ inquiry has been retold in discussion of language acquisition as has taken place since the 1970s. In this context, it is represented as the “ultimate language-learning experiment” (Gleitman & Newport 1995), which constitutes “an incisive bit of scientific prescience” (Rymer 1993). Enlarging on the third, most recent, context for re-telling the story, this article shows how some scholars assimilate it into modern linguistic research, while conceding that it is flawed on ethical grounds. In doing so, they often seem to make the past both inappropriately familiar (therefore less threatening), and inappropriately strange (therefore less valuable). As a result, contemporary citations of this anecdote from the distant past have the paradoxical effect of contributing to fashionable ahistoricity.
Phosphokinase Activity of the Mammary Gland

Summary Mammary gland tissue homogenates phosphorylated glucose, fructose, mannose, and maltose. Glucokinase activity was stimulated by the presence of added magnesium ion. Glucose and mannose were phosphorylated at a maximum rate at lower substrate concentrations than fructose and maltose. Phosphorylation of lactose and galactose did not occur at a significant rate. The evidence indicated that a direct phosphorylation of maltose occurred.
Phase Transitions in the BiVO4-nPbO (n = 1, 2) System: Structural-Electrical Properties Relationships

In a general survey of nPbO-BiVO4 compounds, interesting phases corresponding to n = 1: PbBiVO5, and n = 2: Pb2BiVO6 are described. A phase transition has been unambiguously characterized for PbBiVO5. The crystal structures were solved from twinned crystals at room temperature (α phase, triclinic, S.G. P-1) and at 530°C (β phase, monoclinic, C2/m). Powder neutron diffraction experiments confirmed these settings and both room-temperature (RT) and high-temperature (HT) refinements corroborated space group choices, clearing up a literature controversy about the centrosymmetry of the α phase, and identifying structural modifications occurring under the α → β transition. Cationic substitutions for V were tested and PbBi(V1−x M x )O5 (M = P) solid solutions identified. Pb2BiVO6 (n = 2) is a compound showing several successive structural transitions, i.e., α → β → δ. Structures of α and δ forms have been previously described from powder diffraction data (x-ray and neutron). In this work, we have refined these structures from single-crystal data, and the resolution of the intermediate β form, so far unsolved, was possible through a stabilization thermal cycle; its complete structural understanding required a 4D formalism. Two new polymorphic phases, α′ and δ′, were obtained by substituting Mn or P for V; their structures are closely related to, respectively, the α phase at room temperature, and the δ phase at 680°C. Electrical conductivities of all structurally characterized compositions were investigated, and correlations were drawn between their conduction properties and structural characteristics. Conductivity properties measured under variable O2 partial pressures for Pb2Bi(V0.75P0.25)O6 were interpreted as a mixed ionic–electronic (p-type) conduction mechanism.
Transmembrane topology of subunit N of complex I (NADH:ubiquinone oxidoreductase) from Escherichia coli

The transmembrane topology of subunit N from E. coli Complex I has been investigated. Chemical labeling of mono-substituted cysteine mutants was carried out in inverted membrane vesicles, and in whole cells, using 3-N-maleimidyl-propionyl biocytin (MPB). The results support a model of 14 transmembrane spans with both termini in the periplasm, and are consistent with the models of subunits L, M and N from the crystal structure of the membrane arm of the E. coli Complex I (Efremov et al. (2010) Nature 465, 441–445). In particular, the results do not support an unusual cytoplasmic localization of two likely transmembrane regions, as proposed in previous studies (Mathiesen and Hagerhall (2002) Biochim Biophys Acta 1556, 121–132; Torres-Bacete, et al. (2009) J Biol Chem 284, 33062–33069).
Degeneration and sprouting of identified descending supraspinal axons after contusive spinal cord injury in the rat.

Contusive spinal cord injury (SCI) results in the formation of a chronic lesion cavity surrounded by a rim of spared fibers. Tissue bridges containing axons extend from the spared rim into the cavity dividing it into chambers. Whether descending axons can grow into these trabeculae or whether fibers within the trabeculae are spared fibers remains unclear. The purposes of the present study were (1) to describe the initial axonal response to contusion injury in an identified axonal population, (2) to determine whether and when sprouts grow in the face of the expanding contusion cavity, and (3) in the long term, to see whether any of these sprouts might contribute to the axonal bundles that have been seen within the chronic contusion lesion cavity. The design of the experiment also allowed us to further characterize the development of the lesion cavity after injury. The corticospinal tract (CST) underwent extensive dieback after contusive SCI, with retraction bulbs present from 1 day to 8 months postinjury. CST sprouting occurred between 3 weeks and 3 months, with penetration of CST axons into the lesion matrix occurring over an even longer time course. Collateralization and penetration of reticulospinal fibers were observed at 3 months and were more extensive at later time points. This suggests that these two descending systems show a delayed regenerative response and do extend axons into the lesion cavity and that the endogenous repair can continue for a very long time after SCI.
Incidence of Symptomatic Venous Thromboembolism After Elective Knee Arthroscopy

Background Knee arthroscopy is the most commonly performed orthopaedic procedure in the United States and is usually considered to be a low-risk procedure. The purposes of this study were to describe the incidence of symptomatic deep venous thrombosis, symptomatic pulmonary embolism, and mortality after elective knee arthroscopy performed without thromboembolic prophylaxis, as well as to investigate the association of age, sex, procedure type, and oral contraceptive use with the odds of developing a venous thromboembolism. Methods A retrospective cohort study of elective arthroscopic knee procedures during a twenty-seven-month period (January 1, 2006, through March 31, 2008) was performed with use of the administrative database of a large health maintenance organization. Use of ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) procedure codes for arthroscopic surgery identified 21,794 arthroscopic knee procedures. The occurrence of a symptomatic deep venous thrombosis or pulmonary embolism within ninety days after surgery was identified by reviewing administrative and electronic medical record data for inpatient, outpatient, urgent care, and emergency encounters. Mortality and the cause of death were captured with use of electronic medical records, Social Security Administration Death Master Files, and county death certificates. Patient charts were reviewed for confirmation of the deep venous thrombosis, pulmonary embolism, or death. Patients who had a history of a venous thromboembolism or who had received anticoagulation therapy within fourteen days prior to the index surgery were excluded. Results The study cohort comprised 20,770 patients who met the inclusion criteria. Fifty-one patients (0.25%; 95% confidence interval, 0.18% to 0.31%) developed a deep venous thrombosis, and thirty-five (0.17%; 95% confidence interval, 0.11% to 0.22%) developed a pulmonary embolism. The incidence of venous thromboembolism was higher in patients who were fifty years of age or older (0.51% compared with 0.34% in younger patients), and the incidence in female patients was higher if they had been prescribed oral contraceptive medication (0.63% compared with 0.30% in female patients with no such prescription). No differences in the incidence of deep venous thrombosis or pulmonary embolism on the basis of sex or arthroscopic procedure code were noted. Nine patients (0.04%) died within ninety days of surgery, although only one death was confirmed to have resulted from a pulmonary embolism. Conclusions The ninety-day incidence of symptomatic venous thromboembolism after elective knee arthroscopy was relatively low, with a 0.25% incidence of deep venous thrombosis and a 0.17% incidence of pulmonary embolism. The overall ninety-day mortality after arthroscopic knee surgery was 0.04%.
Survival in patients removed from the heart transplant waiting list before receiving a transplant.

Background Little is known about the outcomes in patients who are removed from the heart transplant (HT) waiting list before receiving a transplant. We sought to analyze outcomes in such patients in the United States (U.S.) in the current era. Methods All patients aged ≥ 18 years old listed for a primary HT in the U.S. between July 2004 and September 2010 were identified. Outcomes in those removed from the list by March 2011 (survival, relisting, HT) were examined using time-to-event analyses. Results Of 15,061 patients listed for primary HT, 10,168 (68%) received a HT, 1,393 (9%) died on the waiting list, and 1,871(12%) were removed before receiving HT. Of patients removed from the list, 560 (30%) were removed due to clinical improvement, 692 (37%) due to deterioration, and 619 (33%) due to other reasons. After removal, 30-day and 1-year survival were 99.6% and 94%, respectively, in patients removed due to improvement and 44% and 26%, respectively, in patients removed due to deterioration. Multivariable predictors of death after removal were removal due to clinical deterioration, hypertrophic or restrictive cardiomyopathy, United Network of Organ Sharing status 1A/1B at listing, and renal dysfunction. Only 27 patients (4.8%) among those removed due to improvement, 21 (3.0%) removed due to deterioration, and 46 (7.4%) removed due to other reasons were relisted. Conclusions One in 8 patients listed for HT in the U.S. are removed from the waiting list before receiving HT. The indication for removal (clinical deterioration vs improvement) is the strongest independent predictor of survival after removal from the list.
Impact of endoscopic therapy on the survival of patients with primary sclerosing cholangitis.

Abstract Background: Endoscopic measures such as balloon dilation can relieve obstruction and improve symptoms in patients with primary sclerosing cholangitis (PSC). However, the influence of repeated endoscopy to maintain biliary patency on the survival of patients with PSC is unclear. Methods: This study evaluated the impact of endoscopic therapy on the survival of consecutive patients with PSC undergoing endoscopic therapy. During a 6-year period 63 patients underwent endoscopic therapy. After initial therapy, patients were followed for a median of 34 months. Endoscopic therapy primarily consisted of repeated balloon dilation of dominant biliary strictures. The observed survival of this cohort was estimated (Kaplan-Meier). The predicted survival of the cohort was estimated by using the Mayo Clinic survival model based on clinical information obtained within 3 months before first endoscopic therapy. The Mayo Risk Score was calculated by using the equation R=(0.03 Age, years) + (0.54 log e Bilirubin mg/dL) + (0.54 log e Aspartate aminotransferase U/mL) + (1.24 Bleed history) − (0.84 Albumin gm/dL). Results: The observed survival over 5 years was significantly higher than the predicted 5-year survival (83% vs. 65%, respectively; p = 0.027). Conclusion: These data suggest that repeated endoscopic attempts to maintain biliary patency may improve the survival of patients with PSC and dominant strictures. (Gastrointest Endosc 2001;53:308-12.)
Beyond Illiterate, What Can You Say?.

This article demonstrates how one might go beyond mechanical errors to describe, measure, and evaluate student writing as communication. Several evaluation procedures were applied to a brief writing protocol submitted by an adolescent learning disabled student. Application of T-unit analysis and primary-trait scoring procedures, and the identification of linguistic cues to intellectual processes all revealed that the student was reasonably mature in the communication of his ideas, although the writing sample was obviously deficient in spelling, capitalization, and punctuation. It was suggested that knowledge of what students can do and adequately describing their competence are the first steps in planning a remedial writing program.
Learning Disability Documentation Decision Making at the Postsecondary Level

Students with learning disabilities (LD) transitioning from secondary school to postsecondary education must submit documentation verifying the existence of a disability and that describes a curren...
A Study of Convective Heat Transfer in a Model Rotor–Stator Disk Cavity

In this study, the fluid (air) temperature field and the convective heat flux distribution on the rotor disk surface were measured and computed in a model rotor-stator disk cavity. Both mainstream flow and secondary air flow were provided. The radial distribution of convective heat transfer coefficient on the rotor disk surface, which was calculated as the ratio of the local heat flux and the local temperature difference across the thermal boundary layer on the disk, is also reported. In the experiments, the disk rotational Reynolds number, Re o , ranged from 4.65×10 5 to 8.6×10 5 , and the nondimensional secondary air flow rate, c w , ranged from 1504 to 7520. The secondary air was supplied at the cavity hub. All experiments were carried out at the same mainstream air flow rate, Re m =5.0×10 5 . The cavity fluid temperature distribution was measured by traversing miniature thermocouples, and the rotor disk surface temperature and heat flux were measured by a quasi-steady thermochromic liquid crystal technique in conjunction with resistance temperature detectors embedded in the disk. The measurements are compared with predictions from the commercial CFD code Fluent. The Fluent simulations were performed in the rotationally symmetric mode using a two-zone description of the flow field and the RNG k-e model of turbulence. The convective heat transfer coefficient distribution on the rotor disk surface exhibited the influence of the source region and the core region of air flow in the cavity. In the source region, which is radially inboard, the convective heat transfer was dominated by the secondary air flow rate. In the core region, which is radially outboard, the heat transfer was dominated by the rotational motion of the fluid relative to the rotor disk. An empirical correlation for the local Nusselt number on the rotor disk surface is suggested for the core region.
Calibrating multi-machine power system parameters with the extended Kalman filter

Large-scale renewable resources and novel smart-grid technologies continue to increase the complexity of power systems. As power systems continue to become more complex, accurate modeling for planning and operation becomes a necessity. Inaccurate system models would result in an unreliable assessment of system security conditions and could cause large-scale blackouts. This motivates the need for model parameter calibration, since some or all of the model parameters could either be unknown or inaccurate. In this paper, the extended Kalman filter is used to calibrate the parameters of a multi-machine power system in the presence of faults. The calibration performance is tested under varying fault locations, parameter errors, and measurement noise giving an insight into how many generators and which generators could be difficult to calibrate.
Clathrin plays a novel role in the regulation of cell polarity, pseudopod formation, uropod stability and motility in Dictyostelium

Although the traditional role of clathrin has been in vesicle trafficking and the internalization of receptors, a novel role in cytokinesis was recently revealed in an analysis of a clathrin-minus Dictyostelium mutant (chc(-)). chc(-) cells grown in suspension were demonstrated to be defective in assembling myosin II into a normal contractile ring. To test whether this defect reflected a more general one of cytoskeletal dysfunction, chc(-) cells were analyzed for cell polarity, pseudopod formation, uropod stability, cell locomotion, chemotaxis, cytoskeletal organization and vesicle movement. chc(-) cells crawled, chemotaxed, localized F-actin in pseudopods, organized their microtubule cytoskeleton in a relatively normal fashion and exhibited normal vesicle dynamics. Although chc(-) cells extended pseudopods from the anterior half of the cell with the same frequency as normal chc(+) cells, they extended pseudopods at twice the normal frequency from the posterior half of the cell. The uropods of chc(-) cells also exhibited spatial instability. These defects resulted in an increase in roundness, a reduction in polarity, a reduction in velocity, a dramatic increase in turning, a high frequency of 180 degrees direction reversals and a decrease in the efficiency of chemotaxis. All defects were reversed in a rescued strain. These results are the first to suggest a novel role for clathrin in cell polarity, pseudopod formation, uropod stability and locomotion. It is hypothesized that clathrin functions to suppress pseudopod formation and to stabilize the uropod in the posterior half of a crawling cell, two behavioral characteristics that are essential for the maintenance of cellular polarity, efficient locomotion and efficient chemotaxis.
A circadian clock nanomachine that runs without transcription or translation

The biochemical basis of circadian timekeeping is best characterized in cyanobacteria. The structures of its key molecular players, KaiA, KaiB, and KaiC are known and these proteins can reconstitute a remarkable circadian oscillation in a test tube. KaiC is rhythmically phosphorylated and its phospho-status is a marker of circadian phase that regulates ATPase activity and the oscillating assembly of a nanomachine. Analyses of the nanomachines have revealed how their timing circuit is ratcheted to be unidirectional and how they stay in synch to ensure a robust oscillator. These insights are likely to elucidate circadian timekeeping in higher organisms, including how transcription and translation could appear to be a core circadian timer when the true pacemaker is an embedded biochemical oscillator.
Topographic Enhancement of Eddy Efficiency in Baroclinic Equilibration

AbstractThe processes that determine the depth of the Southern Ocean thermocline are considered. In existing conceptual frameworks, the thermocline depth is determined by competition between the mean and eddy heat transport, with a contribution from the interaction with the stratification in the enclosed portion of the ocean. Using numerical simulations, this study examines the equilibration of an idealized circumpolar current with and without topography. The authors find that eddies are much more efficient when topography is present, leading to a shallower thermocline than in the flat case. A simple quasigeostrophic analytical model shows that the topographically induced standing wave increases the effective eddy diffusivity by increasing the local buoyancy gradients and lengthening the buoyancy contours across which the eddies transport heat. In addition to this local heat flux intensification, transient eddy heat fluxes are suppressed away from the topography, especially upstream, indicating that local...
Participant Roles and the Processing of Verbs During Sentence Comprehension

This paper explores the nature of thematic information made available when a verb is accessed during sentence comprehension. Following Shapiro, Zurif, and Grimshaw (1987), a cross-modal lexical decision (interference) task was employed to examine whether either the number of argument structures or the number of participant (thematic) roles inherent in a verb cause an increase in processing load upon access of the verb. It was determined that there was no evidence for such an increased processing load covarying with the number of argument structures of the verb, at least for those verb types examined in this study. However, there was an increase in processing load as a direct function of the number of participant roles carried by the verb. It is concluded that the participant roles (thematic roles associated with the central meaning of the verb) are stored with the representation of a verb and are made immediately, available upon access of the verb for further processing during comprehension.
Mappings of power: The state, NGOs, and international organizations in the informal economy of Cairo

L'A. examine les relations entre le pouvoir et l'economie informelle au Caire d'un point de vue ethnographique. Elle a choisi de traiter une forme de pouvoir, l'Etat, a travers ses interstices, les Organisations non gouvernementales et les Organisations internationales. Le probleme, tel que l'economie informelle, se situe en dehors du controle de n'importe quel Etat. Les Organisations internationales, qui lancent les projets de l'economie informelle, s'efforcent de canalyser leurs dynamiques dans un avenir planifie en etablissant leur cartographie. Ainsi, l'economie informelle peut prendre la forme d'un programme de recherche sur le terrain. L'A. pose la question de la frontiere entre la souverainete de l'Etat, les Organisations internationales et la societe civile
Adaptive Web-based learning system

This paper reports a Web-based platform-independent adaptive learning system that serves both students and teachers. The content in the system is individually tailored toward student knowledge, which makes learning more personal, adaptive towards individual needs, and specialized. For teachers, the system provides a generic rules-based library to supervise student learning. These rules enable teachers to choose different assessment, assignment, and learning strategies. The system automatically accommodates these strategies for students according to the teacher's selections and the student's performance. Our system architecture is component-based and Web-based. The learning environment in the system is comparable to classroom learning environments.
Leakage power analysis and reduction: models, estimation and tools

The high leakage current in the nanometre regime is becoming a significant proportion of power dissipation in CMOS circuits as threshold voltage, channel length and gate oxide thickness are scaled. Consequently, the identification and estimation of different leakage currents are very important in designing low power circuits. In the paper a methodology for accurate estimation of the total leakage in a logic circuit based on the compact modelling of the different leakage currents in nanoscaled bulk CMOS devices is demonstrated. Different leakage currents are modelled based on the device geometry, 2-D doping profile and operating temperature. A circuit level model of subthreshold, junction band-to-band tunnelling (BTBT) and gate leakage is described. The presented model includes the impact of quantum mechanical behaviour of substrate electrons on the circuit leakage. Using the compact current model, a transistor has been modelled as a sum of current sources (SCS). The SCS transistor model has been used to estimate the total leakage in simple logic gates and complex logic circuits (designed with transistors of 25 nm effective length) at room and elevated temperatures.
The Effects of a Penicillin Dentifrice on Oral Lactobacilli

Penicillin is known to exert an inhibitory effect on the oral lactobacilli. Hill1 re­ ported a marked decrease in salivary lactobacillus counts following the use of a penicillin dentifrice and mouthwash. After discontinuance of this regime the counts remained low for a time and then returned to their previous level. The pos­ sibility that penicillin-fastness had de­ veloped was considered but was not in­ vestigated. Thus far no reports have appeared concerning the development of resistance to penicillin by the oral lacto­ bacilli under the conditions of in vivo testing. On the other hand we have found it possible to produce penicillin-fastness in a number of human, rat and hamster lactobacillus strains in vitro by transfer­ ring large inocula of susceptible strains through media containing successively higher concentrations of penicillin. The disclosure by Zander that an ap­ parent reduction in the incidence of new caries was occurring in a group of school children using a penicillin dentifrice prompted the experiments to be described in this paper. The purpose was twofold: to determine the effect of continuous use of a penicillin dentifrice on salivary lacto­ bacillus counts, and to ascertain whether the use of such a dentifrice would result in an increased resistance to penicillin by the lactobacilli which persisted in the oral cavity.
The Efficacy of "Little t" Theories

While debates continue about the rigor and relevance of IS research, theories are still widely accepted as the bedrock of scientific research. This paper addresses the issues surrounding academic research rigor and relevance by discussing the rigor and relevance of research theories - in particular, big T and little t theories. Big T theories are usually highly recognized, refined, validated, and generalizable theories usually associated with rigorous research and publication. Little t theories may be relatively immature, little known, narrowly focused, simple, and highly relevant theories more generally appreciated by business practitioners. Little t theories have special characteristics that can be very useful to researchers and teachers, and highly relevant to business practitioners. Moreover, academics can take clear steps to build, publish, teach, and apply little t theories
A NOTE ON REGIONAL DIFFERENCES IN DISCOUNT RATES

THE Federal Reserve Act requires the Board of Directors of the individual regional Reserve bank to fix the discount rate every "fourteen days or less if deemed necessary." It does not require, however, that the discount rate so set be the same as that fixed by all or any other of the Reserve banks. The Board of Governors, with its power of review and determination, could presumably produce uniformity by disapproving all rates failing to fit its preconceptions.' In practice, however, the Board of Governors has not generally carried its authority to such lengths, at least during the postwar period. The "normal" time for a Reserve bank to decide the level of its discount rate would be during the meeting of the full board of directors. The schedule of regular meetings of the boards is as follows:
A short method of estimating lifetime of polypropylene film using step-stress tests

Polypropylene films were tested for lifetimes under high electric fields, using both constant and step-stress methods. Various time intervals for the step-stress test and voltages for the constant stress test were selected. The inverse power law was used in the analysis of the experimental data, with the value of the power exponent determined from the step-stress test. This exponent was found similar to that obtained from the constant stress test. The lifetimes of polypropylene were then estimated from the step-stress test and were found to show good agreement with the experimental results of the constant stress test. The Weibull distribution was employed in the analysis of the experimental data. >
Geographic variation in growth and phenology of two dominant central US grasses: consequences for climate change

Aims The rate of climate change may exceed many plant species' migration rates, particularly for long-lived perennial species that dominate most ecosystems. If bioclimatic envelopes shift more rapidly than dominant species can migrate, individuals located peripheral to biomes or in adjacent biomes may become a significant source of traits for future dominant populations (DPs). Thus, traits of individuals from peripheral populations (PPs) may affect future ecosystem functioning more than those of today's DPs. Methods We assessed key traits of individuals collected from populations that currently dominate two central US grasslands, the shortgrass steppe (Bouteloua gracilis) and the tallgrass prairie (Andropogon gerardii). We compared these to individuals from PPs in a reciprocal-transplant common garden experiment with gardens at the Shortgrass Steppe Long Term Ecological Research site in Colorado and the Konza Prairie Biological Station Long Term Ecological Research site in Kansas. DPs and PPs were subjected to high and reduced water availability in common gardens located in each biome. Traits measured included the following: individual plant biomass, reproductive allocation, specific leaf area (SLA) and plant-water relations. We focused on the climate-change relevant comparisons of traits from PPs versus DPs expressed under the climate of DPs. Important Findings PPs of B. gracilis differed from DPs primarily in phenological traits. Under a semiarid shortgrass steppe climate, PPs initiated flowering later in the season, produced fewer reproductive tillers and were more sensitive to water stress. Biomass differences between populations were minimal. For A. gerardii, biomass in PPs was 50% lower than in DPs under the mesic tallgrass prairie climate and reproductive tillers were considerably smaller, despite higher SLA in PPs. Biomass of PPs was less sensitive to water stress, however. From these results, we conclude that key traits of PPs differed from DPs in both grassland types, but potential effects on reproductive phenology were greater for the bioclimatic shift in which a mesic biome becomes arid, whereas aboveground productivity may be affected more when a semiarid biome becomes more mesic.
Association of Lysozyme with Ribosomes and Ribosome Precursor Particles

Lysozyme, used to prepare osmotically fragile cells, combines with ribosomal subunits unless salt is present in excess of 50 mM. The binding of lysozyme to precursor ribonucleoprotein particles can result in their conversion to particles which sediment as mature ribosomes.
Polyploid evolution via 2n gametes

Polyploid evolution is evident in several important taxonomic series of the tuber-bearing Solanums. Polyploids can result from the functioning of 2n gametes following both intra and inter-ploidy matings. The bilateral and unilateral sexual polyploidizations (BSP and USP, respectively) are greatly facilitated by the existence of genetically determined 2n gametes. Many species, in series containing polyploids, have individuals with 2n gametes. The genetic basis of 2n pollen formation has been established in Phurejahaploid Tuberosum hybrids, and the genetic basis of 2n egg formation is being investigated in these hybrids andS. chacoense. Preliminary results indicate that relatively few genes may be involved. FDR and to a lesser extent SDR 2n gametes avoid the inbreeding in the polyploid that is maximal with somatic doubling. The vigor, fertility and competitive ability of a founder polyploid are dependent on minimizing inbreeding depression. Even more important, polyploids, particularly from FDR 2n gametes, inherit the beneficial epistatic interactions of the parent(s). Genetically determined 2n gametes make systematic sexual polyploidization a recurring phenomenon in two ways. For example, initial BSP of two diploids gives rise to a tetraploid, and thereafter USP ensures continuing contact between ploidy levels resulting in unidirectional introgression. Triploids can also be involved in polyploid evolution if they produce 2n gametes by FDR. Artificial hybridizations indicate that 2n gametes, by overcoming crossing barriers between various ploidy levels, provide the opportunity for continuous gene flow.
Src Homology 2 Domain-Containing Inositol Polyphosphate Phosphatase Regulates NF-κB-Mediated Gene Transcription by Phagocytic FcγRs in Human Myeloid Cells

FcgammaR-mediated phagocytosis is accompanied by the generation of tissue-damaging products such as inflammatory cytokines and reactive oxygen species. Hence, the phagocytic response must be a tightly regulated process. Recent studies have established that clustering FcgammaR on human myeloid cells causes tyrosine phosphorylation of Src homology 2 domain-containing inositol polyphosphate phosphatase (SHIP). However, it is not known how these immunoreceptor tyrosine-based activation motif (ITAM)-bearing phagocytic FcgammaR activate SHIP, or whether the activation of SHIP by ITAMs has any functional relevance. Experiments addressing the mechanism of SHIP association with ITAMs have been done in in vitro systems using phosphopeptides. In this study we undertook to dissect the molecular mechanism by which SHIP associates with the native ITAM-FcgammaR and becomes phosphorylated. In this report we provide evidence that first, SHIP is indeed phosphorylated by ITAM-FcgammaR, using cell systems that lack FcgammaRIIb expression; second, coimmunoprecipitation experiments demonstrate that SHIP associates with native ITAM-bearing FcgammaRIIa in vivo; and third, phosphorylation of SHIP by FcgammaRIIa is inhibited by overexpressing either the SHIP Src homology 2 domain or a dominant negative mutant of Shc. In contrast, SHIP phosphorylation was not inhibited by a dominant negative mutant of Grb2. We extend these observations to show that SHIP activation by ITAM-FcgammaR down-regulates NF-kappaB-induced gene transcription. These findings both provide a molecular mechanism for SHIP association with native ITAM-bearing receptors and demonstrate that SHIP association with ITAM-FcgammaR serves to regulate gene expression during the phagocytic process.
Cognitive Decline in Presymptomatic Alzheimer Disease.

Fundamentalquestions remain in thesearch for thecauseand treatment of Alzheimer disease (AD). As yet, it is not fully known what mechanisms trigger the sequence of neurologic changes that lead to neuronaldeathanddementia.1,2An often-cited model proposes thatAPP in thebrain is abnormallycleaved intosmallerparticles thatproducea toxicβ-amyloidpeptide,whichclump intoextracellularplaques.The toxic effectsofAβ inducehyperphosphorylationof themicrotubuleassociated protein tau, causing neurofibrillary tangles, cell death, andsubsequentdementia.3Measuresof thesebiomarkers can be obtained from cerebrospinal fluid andwith neuroimaging. Thismodel has beenmodified to allow amore complex temporal orderingof somebiomarkers.4More important, thismodel suggests that thediseasebeginsdecadesbefore the onset of clinical symptoms. The most common risk factor is age. To date, no effective treatment has been found.5 Treatment that will delay or slow progression of AD likely will depend on early detection. Episodicmemory impairment is the earliestmarker of dementia in most cases. Longitudinal studies6,7 of participants at risk for AD by virtue of old age have found that a slow decline inmemoryprecedes aperiodof acceleratedmemorydecline, leadingtodementia.Somestudies8,9havefoundthatcognitive measures are at least as sensitive to disease onset as neuropathologic biomarkers. Apromising lineof research is thestudyof individualswith oneof the rare geneticmutations that causes autosomaldominantAlzheimer disease (ADAD). This formof the disease contrasts with most sporadic, late-life cases in which no singlegenemutation is responsible.MostcasesofADADare the result of a single PSEN1 (GenBank NM_000021) mutation, and others are caused bymutations of PSEN2 (GenBank NG_007381) or APP. Carriers can be identified at an early age presumably before the disease begins. Longitudinal studies of ADADoffer auniqueopportunity tomeasureprogression inbiomarker abnormalities from the earliest changes to the full clinical expressionof thedisease. The importanceof longitudinal analysis was demonstrated by the finding that concentrations of biomarkers can decrease, rather than continue to increase or stay the same, as ADAD progresses.10 The studybyAguirre-Acevedo et al11 in this issue of JAMA Neurology exploreswhen cognitive decline ismeasurable and what cognitive functions are the earliest to change. They present data of a kindredofPSEN1E280AcarrierswithADAD followed up longitudinally for 20 years who at study entrywere 18 years and older. A total of 493 carriersmet the study inclusion criteria, and 256 carriers were examined twice or more with theConsortiumtoEstablishaRegistry forAlzheimer’sDisease (CERAD) test battery12 at 2-year intervals with a median follow-upof 5 years.Most (386 [78.3%])were cognitively normal, whereas 51 (10.3%) had symptoms of mild impairment (ClinicalDementiaRating,0.5).Word listmemoryhad theearRelated article page 431 Opinion Editorial
Antibiotic effect of tylosin on a mycoplasma contaminant in a tissue culture leukemia cell line.

SummaryA tissue culture line of murine virus-induced leukemia cells was contaminated by a strain of mycoplasma (PPLO) which may be or is related to M. granularum. This organism was resistant to treatment with tetracyclin, kanamycin, erythromydn, chloromycetin, polymixin, stovarsol and iodine, but sensitive to Tylosin. Two consecutive treatments with Tylosin (Purina tylan) at a concentration of 50 μg/ml were non-toxic to the cells and were effective in ridding the cultures of PPLO.