cssi/SciSciGPT-SciSciNet huggingface dataset:
Spatial representation by young infants: categorization of spatial relations or sensitivity to a crossing primitive?

The spatial representation abilities of 3- to 4-month-old infants were examined in four experiments. Experiments 1 and 2 showed that infants familiarized with a diamond appearing in distinct locations to the left or right of a vertical bar subsequently preferred a stimulus depicting the diamond on the opposite side of the bar over a stimulus depicting the diamond in a novel location on the same side of the bar. Experiment 3 was a replication of Experiment 1, except that the bar was oriented at 45°. In this instance, infants divided their attention between the stimulus depicting the diamond on the opposite side of the bar and the stimulus depicting the diamond in a novel location on the same side of the bar. Experiment 4 demonstrated that the results of Experiment 3 were not a consequence of a failure to process the diagonal bar. When considered with previous reports that infants can represent the categories ofabove andbelow (Quinn, 1994), the present results suggest that (1) infants can also represent the categories of left and right, and (2) performance cannot be interpreted as a response to an arbitrary crossing of one object relative to another. Although recent discussions of the relation between language and cognition have pointed to the ways in which spatial language influences spatial cognition (Bowerman & Levinson, 2001), the present findings are consistent with an influence in the opposite direction: Spatial cognition may in some instances shape spatial language.
Clean Inversion of Configuration in the Pd-Catalyzed Cross-Coupling of 2-Bromo-1,3-dienes

The Pd-catalyzed cross-coupling reaction of 2-bromo-1,3-dienes derived from alkyl aldehydes, especially with Cl2Pd(DPEphos) as a catalyst, proceeds with clean stereoinversion of the Br-bearing CC bond to produce in high yields and in high stereoselectivity (≥97−98%) conjugated Z,E dienes of potentially high utility in the synthesis of complex natural products. The observed stereoinversion cannot be readily accommodated by the widely accepted π−σ−π rearrangement mechanism for isomerization of ordinary allylpalladium derivatives.
Spin determination of intermediate structure in the subthreshold fission of $sup 237$Np

A polarized neutron beam and a polarized target have been used to determine spins of 15 intermediate structure groups observed in the fission of / sup 237/Np below 1 keV and of 94 resonances observed in transmission below 102 eV. The pulsed neutron beam, from the Oak Ridge electron linear accelerator, was polarized by transmission through a dynamically polarized proton sample. The / sup 237/Np, in the ferromagnetic compound NpAl/sub 2/, was cooled by a /sup 3/He-/ sup 4/He dilution refrigerator. Nine individual fine-structure resonances comprising the first group at 40 eV were determined to have the same spin, J = 3, substantiating the current interpretation of intermediate structure in subthreshold fission in terms of the Strutinsky double-humped deformation barrier. Correlation of these results with existing data on the angular distribution of fission fragments from aligned /sup 237/Np indicates an apparent admixing of transition states, as evidenced by nonintegreal values of the projection quantum number, K. (auth)
Mortality and safety of catheter ablation for antiarrhythmic drug-refractory ventricular tachycardia in elderly patients with coronary artery disease.

Background As the population ages, recurrent ventricular tachycardia (VT) is increasingly encountered in elderly patients with ischemic heart disease. Radiofrequency catheter ablation is useful for reducing VT therapy in patients with an implantable defibrillator. The utility of radiofrequency catheter ablation in the elderly is not well defined. Objective The purpose of this study was to evaluate the prognosis and safety of radiofrequency catheter ablation of postinfarct VT in elderly patients. Methods Radiofrequency catheter ablation was performed in 285 consecutive patients with recurrent postinfarct VT refractory to antiarrhythmic drugs. Mortality and outcomes were compared for an elderly group (age ≥75 years, n=72) and a younger group (age Results The groups were similar with regard to baseline characteristics, except for a greater number of females in the elderly group (20.8% vs 10.8%, P = .03). Inducible VTs were abolished or modified in 79.2% of the elderly group and 87.8% of the younger group ( P = .12). Major complications occurred in 5.6% of elderly patients and 2.3% of younger patients ( P = .48). Periprocedural mortality was similar between both groups (2/72 in elderly and 9/213 in younger group, P = .74). During mean follow-up of 42 ± 33 months, 50.0% of the elderly group and 35.2% of the younger group died ( P = .08). No VT was observed in 63.9% of the elderly patients and 60.1% of the younger patients, respectively (mean follow-up 18 ± 24 months, P = .80). Conclusion Outcomes of catheter ablation are similar for selected elderly and younger patients. Advanced age should not preclude ablation when recurrent VT is adversely affecting quality of life in elderly patients who otherwise have a reasonable expectation for survival.
An ecological study of fucus spiralis L.

Abstract An ecological study of Fucus spiralis L. has been made at Jaffrey Point, Newcastle, New Hampshire and the adjacent Great Bay Estuary System from 1972–1975. The distribution, growth, reproductive periodicity, attrition and longevity of the plants are described in relation to a variety of environmental factors. F. spiralis shows a broad but discontinuous estuarine distribution within the Great Bay Estuary System. The presence or absence of appropriate substrata is considered to be a factor determining its discontinuous distribution, since it is usually associated with metasedimentary or metavolcanic rock outcrops. The maximum growth and reproduction of F. spiralis are during the summer. The summer growth rates ranged from 1.9 to 2.8 cm/month while the average growth rate throughout the year was 1.2 cm/month. F. spiralis populations showed two periods of major attrition, namely, during the winter and summer. The average longevity of F. spiralis plants is ≈ 2 yr. The F. spiralis zone lies in the uppermost intertidal area between +2.12 and +2.31 m above M.L.W. There is a micro-stratification of biomass, stature, and reproductive activity within this zone. Average plant weight, length, and fertility tend to decrease with increasing elevation.
Divorcing ARF and p53: an unsettled case

Mammalian cells that sustain oncogenic insults can invoke defensive programmes that either halt their division or trigger their apoptosis, but these countermeasures must be finely tuned to discriminate between physiological and potentially harmful growth-promoting states. By functioning specifically to oppose abnormally prolonged and sustained proliferative signals produced by activated oncogenes, the ARF tumour suppressor antagonizes functions of MDM2 to induce protective responses that depend on the p53 transcription factor and its many target genes. However, ARF has been reported to physically associate with proteins other than MDM2 and to have p53-independent activities, most of which remain controversial and poorly understood.
Evaluation and optimization of experimental conditions for surface-enhanced Raman detection of analytes in flow injection analysis

Abstract Surface-enhanced Raman spectrometry (SERS) is potentially a powerful analytical tool. The present study evaluates the experimental conditions required to obtain reproducible SERS signals of two model compounds, p -aminobenzoic acid and 9-aminoacridine, introduced into a flowing stream. The critical parameters in the preparation of the silver sols and the introduction of the analyte include concentrations of reagents, time of activation of the sols, time of interaction of the aggregated particles and the analyte, and the acidity of the flowing stream. Under the controlled experimental conditions of flow injection analysis, the reproducibility for measuring a 20-μl sample of 10 μg/ml p -aminobenzoic acid is 3.2% and the detection limit is 30 ng.
Photoluminescence Quenching of Conjugated Macromolecules by Bipyridinium Derivatives in Aqueous Media: Charge Dependence

Quenching of the photoluminescence from a water-soluble conjugated macromolecule, poly[5-methoxy-2-(4-sulfobutoxy)-1,4-phenylenevinylene], by neutral 4,4‘-dipyridyl and by six bipyridinium derivati...
Thyrocalcitonin and bone resorption. Studies employing a tissue culture bioassay.

Abstract Thyrocalcitonin, partially purified from rat thyroid glands, is a potent inhibitor of resorption in tissue cultures of fetal rat bone. This inhibition is best demonstrated when resorption is stimulated by parathyroid hormone, but can occur independently. The ability of thyrocalcitonin to block bone resorption stimulated by parathyroid hormone in tissue culture has provided a sensitive, specific and reproducible bioassay which can be used to detect thyrocalcitonin-like activity in serum. The results of this bioassay indicate that the serum of thyroid-intact rats contains an inhibitor of bone resorption which appears after a hypercalcemic stress. The amount of thyrocalcitonin activity was similar in parathyroidectomized rats, which required injections of large amounts of calcium to increase their serum calcium concentration from low to hypercalcemic values, and rats with parathyroid transplants which required only small amounts of calcium to increase their serum calcium concentration from normal to similar hypercalcemic values. Thyrocalcitonin-like activity could not be demonstrated in the serum in the absence of a calcium stress. Prolonged administration of thyrocalcitonin in tissue culture results in an escape of the bone from its inhibitory effect and the resumption of active bone resorption in the presence of parathyroid hormone and thyrocalcitonin. This escape phenomenon was due to the continuous presence of partially purified thyrocalcitonin and not to any changes in the cells during tissue culture or to the presence of parathyroid hormone. The data fit the hypothesis that thyrocalcitonin is an emergency hormone secreted only intermittently in response to hypercalcemic stress. Its action is to inhibit bone resorption, resulting in a decrease in the movement of calcium from bone to blood and a lower serum calcium concentration.
High capacity Si/C nanocomposite anodes for Li-ion batteries

Abstract Nanocomposites of Si/C were synthesized from Si and polystyrene (PS) resin using high-energy mechanical milling (HEMM) followed by subsequent heat-treatment. The resultant nanocomposites are comprised of amorphous carbon and nanocrystalline silicon as verified by X-ray diffraction (XRD). The XRD results also indicate the presence of iron silicide (FeSi) arising as a contaminant during HEMM. The Si/C nanocomposite corresponding to Si:C = 1:2 composition obtained after milling in two stages of 12 h each for a total time period of 24 h shows a capacity as high as ∼850 mAh/g with reasonable capacity retention (∼1.1% loss/cycle). The increase in either heat-treatment temperature or milling time renders the nanocomposites more stable at the expense of capacity. Transmission electron microscopy (TEM) analysis shows that the HEMM derived Si nanocrystallites
A fission ionization detector for neutron flux measurements at a spallation source

Abstract The construction of a neutron flux monitor that can measure absolute neutron intensities in the neutron energy range from below 1 MeV to over 500 MeV is described. The detector consists of an ionization chamber with several thin deposits of fissionable material. The ionization chamber is thin enough that it does not significantly affect the neutron beam and may be left in the neutron flight path during experimental measurements to continuously monitor the beam flux. The use of this monitor at the continuous-energy spallation neutron source at the WNR target area at LAMPF is described.
An analysis of proton fluxes coupled to electron transport and ATP synthesis in chloroplast thylakoids

Abstract Electron transport, phosphorylation and internal proton concentration were measured in illuminated spinach chloroplast thylakoid membranes under a number of conditions. Regardless of the procedure used to vary these parameters, the data fit a simple chemiosmotic model. Protons from Photosystem II did not appear to be utilized differently from those derived from Photosystem I. The maximal phosphorylation efficiency ( P e 2 ) for photophosphorylation in washed thylakoids under oxidizing conditions is likely to be 4 3 . This value is consistent with a proton-to-electron-pair ratio of 4 for electron flow through both photosystems and a proton-to-ATP ratio of 3 for the chloroplast proton-ATPase.
Multi-Period Expectations and the Term Structure of Interest Rates

I. Equivalence of the Hicks-Lutz and Malkiel theories, 321. — II. Meiselman on expectations, 325. — III. Conclusion, 328.
The artifactual nature of effects of maternal age on risk of stillbirth.

Analysis of stillbirth data from the stat of Wisconsin demonstrates that the association of stillbirth rate with mothers age is basically an artifact of analysis rather than a reflection of geniune effects of age on risk. When births to mothers of a single parity are subdivided according to amount of education completed by the mother the association between stillbirth rate and maternal age in each eductional group differs substantially from the others. The association observed for all births of a single parity is inapplicable to any educational subdivision of the data. It is argued that the associations which are observed are the consequence of social forces which distribute women of varying intrinsic risk of stillbirth unevenly among age-parity categories. (authors)
Atom pair partitioning of the correlation energy

Abstract Using our atomic orbital formulation of the electronic structure problem, contributions to the correlation energy are condensed over pairs of atomic centers. We show that the resulting pair energies can be used to understand how correlation energy is distributed throughout a molecule. These pair energies reflect the near-sightedness of the correlation energy while offering a simple way to represent and quantify intramolecular interactions. In particular, the dependence of these interactions with basis set is explored. We propose that strong or active interactions be treated using large basis sets while weak or inactive interactions are treated using a smaller basis set.
"Nasal gliomas" and related brain heterotopias: a pathologist's perspective.

Brain heterotopias are rare congenital malformations embryologically related to encephaloceles. They present as a mass in or about the nose (nasal glioma) or in the nasopharynx. We present the clinical and pathological features of 5 cases of heterotopic brain tissue. Four nasal gliomas consisted of mature neuroglial tissue, including neurons in 2 cases, embedded in a fibrovascular stroma. A nasopharyngeal brain heterotopia showed histologic features of mature neuroglial tissue including neurons and ependymal-lined cystic structures. The finding of mature neuroglial tissue in a mass from the head and neck region raises three differential diagnostic possibilities: teratoma, encephalocele, or heterotopic tissue. A teratoma can be ruled out by examination of the entire specimen. Encephaloceles and brain heterotopias can be distinguished only after correlation with the patient's clinical and radiologic findings.
Seafloor Spreading, Sea Level, and Ocean Chemistry Changes

High Cretaceous ocean crust production rates have been causally linked to high global sea level and global CO2 due to increased outgassing. However, recent studies have questioned the empirical basis for high Cretaceous global seafloor spreading rates, high Cretaceous sea level (230–320 m above present), and the relationship between geochemical fluxes and spreading rates. Although this topic has been discussed at several recent international meetings, there has been little opportunity for the protagonists in the debate of constant versus variable global seafloor spreading rates to interact. However, a group of tectonophysicists, stratigraphers, and geochemists recently met at Rutgers, The State University of New Jersey (Piscataway N.J.) to discuss global seafloor spreading changes and their possible relationships to sea level and geochemical variations.
Analytic problems in the identification of wars

The paper examines some of the conceptual and methodological problems involved in identifying interstate wars, particularly wars among the great powers during the 1495–1815 period. The definition of war as substantial armed conflict involving the organized military forces of independent political units leads directly to three major sets of problems regarding the operational identification of wars: identification of the actors whose wars are to be analyzed; specification of a minimum threshold of violence or intensity of interaction for qualification as a war; and boundary problems concerning the determination of the beginning and end of a war and the aggregation or disaggregation of simultaneous or sequential wars. Problems of index construction, validity and reliability, data sources and biases, and data availability are critical. Problems involved in measuring the attributes of war, including its duration and severity, are dealt with primarily in terms of their relevance for the issue of identifying war...
Positivity of the best unbiased L-estimator of the scale parameter with complete or selected order statistics from location-scale distribution

Abstract The positivity of the best linear unbiased estimator of the scale parameter of a location-scale family of distributions in terms of complete or selected set of order statistics has only been conjectured in the literature based solely on empirical evidence. This paper offers an analytical proof of this conjecture for distributions whose densities are log-concave.
719 AN ALTERNATIVE INTERPRETATION OF THE ENZYME DEFICIENCY IN THE GUNN RAT

Bilirubin glucuronyl transferase activity (BGT) is negligible in jaundiced (jj) Gunn rats, with intermediate and higher levels in heterozygous (Jj) and outbred (JJ) rats, respectively. This could be explained either by a defective enzyme or structural defects in the endoplasmic reticulum in which the enzyme is compartmented. If the latter interpretation is correct, similarly segregating activities might be expected among other microsomal enzymes. The activity of aminopyrine demethylase (AD), a hepatic microsomal mixed-function oxidase, was assayed in male jj, Jj, JJ Gunn and Wistar (Wi) rats. BGT (μg bilirubin conjugated/30 min/mg protein N) and AD (nmoles CH2O produced/min/mg protein) are shown below (mean±SD). Results: jj AD jj or JJ rats (p < .05). A correlation (r=.81) exists between BGT and AD (p < .01) in JJ rats, but not in Jj rats. The data suggests a microsomal membrane defect in enzyme compartmentation may be the primary abnormality in the Gunn rat and possibly in Crigler-Najjar Syndrome.
Outcome of patients with blunt trauma transferred after diagnostic or treatment procedures or four-hour delay.

Study objective: This study was conducted to assess the outcome of patients suffering multiple injuries from blunt trauma who were transferred to a Level I trauma center for definitive care after special diagnostic or treatment procedures (DTPs) or after a simple delay of four hours at a primary receiving hospital. Design: Retrospective review of aeromedical registry data and clinical chart review. Measurements: Aeromedical trauma transfers made during a four-year period were studied. The TRISS method was used to determine predicted survivals for DTP patients, patients transferred after a four-hour delay, and patients transferred promptly. Results: The observed survival for 469 aeromedically transferred patients with blunt trauma was the same as that predicted by TRISS analysis (394 vs 392.5). Survival for 86 patients with DTP was also the same as predicted (62 vs 61.6). Outcomes for nonDTP patients and for 92 patients experiencing a delay in transport of four hours or more were also the same as predicted. Conclusion: Early versus delayed decision to transfer patients with blunt trauma did not appear to influence overall outcome. These data suggest that minor delays in recognizing the need to transfer patients with blunt injuries to a trauma center for definitive care may be offset by rapid, skilled transfer and highly specialized trauma care and support the hypothesis that regional trauma center care after initial evaluation and resuscitation elsewhere can be effective even when the timing of transfer is not ideal.
Symposium 1: Regulation of Neural Development by BMP and Activin Family Members: XXXX

The effects of BMP family members on stem cell lineage commitment depend upon the developmental age of the stem cell. BMP4 promotes apoptosis of early ventricular zone (VZ) stem cells, neuronal differentiation of later stage VZ cells, and astroglial differentiation of subventricular zone (SVZ) cells. BMP4 inhibits oligodendroglial lineage commitment at all stages of development. The effects of BMP4 in promoting commitment to a specific lineage reflect active suppression of alternate lineages by transcriptional inhibitors including ID and HEY family members and others. For example, BMP mediated increases in ID expression in SVZ stem cells suppress both oligodendroglial and neuronal differentiation. Similarly HEY 1 expression in SVZ cells suppresses neuronal differentiation, whereas HEYL expression by VZ cells inhibits glial differentiation and promotes neurogenesis. The differing effects of the BMPs on VZ and SVZ stem cells reflect also differences in the complement of transcription factors that are expressed. For example, VZ stem cells express high levels of neurogenin and HEY L whereas SVZ stem cells express lower levels of these factors but higher levels of HEY1. Thus lineage commitment by stem cells reflects interplay among stimulatory and inhibitory transcription factors, and responses to the BMPs depend upon the repertoire of transcription factors already expressed by the cell.
Optimum angle of incidence for observing thin-film interference colors

A colorimetric analysis of white-light interference colors for transparent films on absorbing substrates has shown that specific angles of incidence exist for which the purity of interference colors is predicted to be greatest for s- or p-polarized light. These optimum angles of incidence depend primarily on the optical constants of the substrate, and they decrease from the first to the third order of interference. They provide the best conditions for the determination of film thicknesses from interference colors, and their use is essential for making interference colors visible with highly reflective substrates. As an alternate measure of the observability of interference colors, a polychromatic fringe visibility has been introduced. Its use provides similar predictions of optimum angles. The computations are in good agreement with experimental observations.
Twins, placentas, and genetics: acardiac twinning in a dichorionic, diamniotic, monozygotic twin gestation.

We describe a human acardiac twin with associated vascular anastomoses in a dichorionic diamniotic fused twin placenta. A 22-year-old woman delivered a healthy 3,554 g male infant and a fused diamniotic dichorionic twin placenta with a 230g umbilical cord-attached, skin-covered, ovoid mass, consistent with acardiac amorphus. By gross and histological examination, the placental dividing membranes comprised four leaves, one amnion from each placenta, and two centrally fused chorions, diagnostic of dichorionicity. Placental barium injection of the normal twin's umbilical vein showed an anastomosis with the acardiac twin which traversed the dividing membranes, then supplied major vessels of the acardiac mass via its 5.5 cm umbilical cord. DNA-typing studies of the normal twin's placenta and of the acardiac twin's tissues revealed identical alleles at 11 distinct genetic polymorphic loci, consistent with monozygosity. Our findings demonstrate that vascular anastomoses can occur in dichorionic twin placentas, and that human acardiac twinning is not, as heretofore believed, restricted to monochorionic placentas.
Quasi-particle mean-free-path and thermal hall conductivity in YBa2Cu3O7

Abstract We have measured the Hall component of the thermal conductivity κ xy e in the mixed state of YBCO. κ xy e is observed to be unusually large. From its strong field dependence we deduce the quasi-particle mean free path l 0 . Between 90 K and 15 K, l 0 increases rapidly from 80 A to 2500 A.
Low resistivity CdS(In) films prepared by spray pyrolysis

Abstract Low resistivity films of CdS doped with indium were prepared by spray pyrolysis. The resistivity was measured as a function of both the cadmium-to-sulfur molar ratio and the amount of hydroxylamine hydrochloride (NH 2 OH·HCl) added to the starting spray solution. The amount of indium was kept constant at 3 mol.%. For a Cd:S ratio of 1:0.9 the resistivity drops by about two orders of magnitude from 3400 to 16Ω cm as the NH 2 OH·HCl:Cd ratio is varied from 0 to 4. For Cd:S ratios of 1:1.2 and 1:1.5 the resistivity increases linearly for the same variation of NH 2 OH·HCl:Cd going from 1.5 to 8 Ω cm and from 0.68 to 6.8 Ω cm respectively. These results are discussed in terms of the Cd:S ratio in these systems.
Effects of water pollutants and other chemicals on fish acetylcholinesterase (in vitro).

Acetylcholinesterase (AChE) preparations from the muscle of the fathead minnow (Pimephales promelas Rafinesque) were treated (in vitro) with 74 chemicals of various classes, many of which are environmental contaminants, to determine their effect upon enzyme activity. A highly inhibitory effect was found with several carbamates, one organoxy-phosphate, the arsenite ion, and certain heavy metal cations. Intermediate inhibition was found with the arsenate ion, other metal cations, organometals, certain neuroactive agents, organophosphates, and one organochloride pesticide. Several organochloride pesticides, alkaline and alkaline—earth cations, a variety of anions, several drugs, and other chemicals had little inhibitory effect at the highest concentration used (0.01 m). The effect of chemicals in mixtures of known composition was approximately additive. None of the chemicals tested caused detectable enzyme activation.
Using Agent Technology for Company Knowledge Management

Emerging agent-based systems offer a new means of effectively managing knowledge to address complex decision processes, thereby enabling solutions to many real problems that have heretofore appeared intractable. This article presents an overview of expert system and agent technologies, and shows the latter as a powerful extension of artificial intelligence for systems development. To illustrate, a system developed first using an expert system approach and then an agent-based approach is used to identify the strengths and weaknesses of the agent-based approach. Last, the practical implications of a company adoption of agent-based technology for systems development are addressed.
The Effect of Protic Doping Level on the Anticorrosion Characteristics of Polyaniline in Sulfuric Acid Solutions

In a previous paper we investigated the mechanism by which fully protically doped (emeraldine-salt form) polyaniline (PANI) protects stainless steel surfaces from corrosion in I M sulfuric acid solution. A mechanism was proposed, based on prior work by Deng et al., whereby passivation is achieved because the emeraldine-salt form holds the potential of the underlying stainless steel electrode in the passive region. This paper describes investigations of PANI-coated stainless steel surfaces exposed to more dilute sulfuric acid solutions. This is an interesting issue because while the solution becomes less corrosive as the concentration of the H 2 SO 4 decreases, the concomitant change in pH also changes the protic doping level of the PANI film. UV-visible spectroscopy indicated that partially protic films are obtained upon exposure of PANI to solutions with H 2 SO 4 concentrations in the range from 500 to 1.0 mM. Exposure to 0.1 mM H 2 SO 4 yielded the protically undoped emeraldine-base material. We have found that both the partially protically duped PANI films and the totally undoped emeraldine-base films also hold the potential of the substrate stainless steel electrode in the passive region. Hence, the mechanism by which PANI protects the underlying metal surface from corrosion is independent of doping level.
The Role of Assessment in Secondary Physical Education—A Pedagogical View

Abstract Physical educators might wonder how many of our secondary physical education classes represent “real” physical education and how many represent “pretend” physical education. Many agree that real physical education focuses on student learning and active student involvement.
Ion extraction and optics arithmetic

Abstract Arithmetic algorithms for ion extraction from a plasma are examined, instabilities are delineated, and ancillary results are presented.
Laser-induced fluorescence characterization of ions in a magnetron plasma

We report for the first time laser‐induced fluorescence measurements of a sputtering magnetron plasma. From these measurements we determined the density, average velocity, and temperature of the ions. The ion density profile is peaked at the same location as the electron density profile, which was measured with a Langmuir probe. The average ion velocity parallel to the cathode surface is less than our detection limit of 93 m/s. The ions at the edge of the discharge are room temperature, while in the center of the discharge they reach a temperature of 0.64 eV. These temperatures are attributed to acceleration of the ions by the electric field in the plasma, together with collisional scattering.
Well water contamination in a rural community in southwestern Pennsylvania near unconventional shale gas extraction

Reports of ground water contamination in a southwestern Pennsylvania community coincided with unconventional shale gas extraction activities that started late 2009. Residents participated in a survey and well water samples were collected and analyzed. Available pre-drill and post-drill water test results and legacy operations (e.g., gas and oil wells, coal mining) were reviewed. Fifty-six of the 143 respondents indicated changes in water quality or quantity while 63 respondents reported no issues. Color change (brown, black, or orange) was the most common (27 households). Well type, when known, was rotary or cable tool, and depths ranged from 19 to 274 m. Chloride, sulfate, nitrate, sodium, calcium, magnesium, iron, manganese and strontium were commonly found, with 25 households exceeding the secondary maximum contaminate level (SMCL) for manganese. Methane was detected in 14 of the 18 houses tested. The 26 wells tested for total coliforms (2 positives) and E. coli (1 positive) indicated that septic conta...
All patients with small intramural rectal cancers are at risk for lymph node metastasis.

PURPOSE: Although local excision can be curative in patients with early-stage rectal cancer, approximately 20 percent of patients will develop local recurrence, many as a result of unrecognized and unresected regional lymph node metastases. Our objective was to determine if standard pathologic factors can predict lymph node metastases in small intramural rectal cancers and provide a basis for patient selection for nonradical surgery. METHODS: Between June 1986 and September 1996, 318 patients with T1 or T2 rectal cancers underwent radical resection at our institution. Of these, 159 patients (48 T1 and 111 T2) were potentially eligible for curative local excision (≤4 cm in size, ≤10 cm from the anal verge, no synchronous metastases), and the prevalence of lymph node metastases based on T stage and other pathologic factors was analyzed in this group. RESULTS: The overall frequency of lymph node metastasis was 15 percent (24/159 patients). T stage (T1, 10 percent; T2, 17 percent), differentiation (well-differentiated or moderately differentiated, 14 percent and poorly differentiated, 30 percent), and lymphatic vessel invasion (lymphatic vessel invasion-negative, 14 percent and lymphatic vessel invasion-positive, 33 percent) influenced the risk of lymph node metastasis. However, only blood vessel invasion (blood vessel invasion-negative, 13 percent and blood vessel invasion-positive, 33 percent) reached statistical significance as a single predictive factor (P=0.04). Tumors with no adverse pathologic features (low-risk group) had a lower overall frequency of lymph node metastasis (11 percent) compared with the remaining tumors (high-risk group, 31 percent;P=0.008). However, even in the most favorable group (T1 cancers with no adverse pathologic features) lymph node metastases were present in 7 percent of patients. CONCLUSION: In rectal cancer patients potentially eligible for local excision, the overall risk of undetected and untreated lymph node metastases is considerable (15 percent). The use of pathologic factors alone after local excision does not reliably assure the absence of lymph node metastases.
A Nicotinic Acetylcholine Receptor Is Involved in the Acrosome Reaction of Human Sperm Initiated by Recombinant Human ZP3

One of the essential steps in mammalian fertilization is the acrosome reaction (AR), a modified exocytotic event in the sperm head that occurs upon contact with the glycoprotein matrix of the zona pellucida (ZP) surrounding the oocyte. Acetylcholine (ACh) at concentrations of 10-250 micro M and nicotine at 10-250 nM significantly initiate the AR of capacitated human sperm. Preincubation with three antagonists of the nicotinic acetylcholine receptor (nAChR), alpha-bungarotoxin (alpha-BTX, 100 nM), alpha-conotoxin IMI (alpha-CTX IMI, 250 nM and 25 nM), and methyllycaconitine (MLA, 100 nM and 10 nM), significantly blocked AR initiation by ACh. alpha-BTX is an anatagonist of several nAChRs, including the alpha7 nAChR, and alpha-CTX IMI and MLA are highly specific antagonists of alpha7 subunit-containing AChRs. The sperm nAChR plays a role in the AR initiated in vitro by a purified recombinant human ZP protein (rhZP3). Previously, rhZP3 was able to stimulate the AR by mechanisms similar to those seen with native ZP. Preincubation of human sperm with alpha-BTX (from 10 micro M to 100 nM), alpha-CTX IMI (250 and 100 nM), or MLA (100 nM and 10 nM) caused a significant inhibition in the rhZP3-initated AR. The inhibition of the ACh-initiated and rhZP3-initiated AR by these nAChR antagonists strongly suggests the involvement of an alpha7 subunit-containing nAChR in the AR initiated by both ligands. AR initiation by progesterone was not inhibited by MLA or alpha-BTX, suggesting that this particularnAChR is not involved in the AR initiated by that ligand. In vitro results show for the first time that ACh can initiate the human sperm AR and strongly suggest that a human sperm alpha7 subunit-containing nAChR plays a role in the rhZP3-initiated AR. This nAChR ligand-gated ion channel may be important to the signal transduction events of ZP-initiated AR in vivo.
Intracellular studies on the effects of systemic administration of serotonin agonists on rat facial motoneurons.

Abstract Intracellular recordings were made from facial motoneurons of anesthetized rats during systemitic administration of 5-methoxy-N,N-dimethyltryptamine N-dimethyltryptamine (5-MeODMT) and p-chloroamphetamine (PCA), drugs which elicit the behavioral serotonin syndrome. Both drugs caused a slow depolarization, increased input resistance, and increased excitability of facial motoneurons. These changes are identical to those caused by direct microiontophoretic application of serotonin to these neurons, and probably underlie some of the components of the behavioral serotonin syndrome.
Potential dependence of the enthalpy of activation for the electroreduction of Pb(II) in dimethylformamide

In the following paper, we present data for the electroreduction of Pb 2+ in dimethylformamide, and demonstrate that double layer effects on the enthalpy of activation are large. These effects are considered with respect to possible mechanisms for the reaction, and the location of the rate determining step in the double layer
Exploratory aspects of variability in learning a novel skill

Movement variability has been typically thought as detrimental, but it also plays a positive role for perception and action. One positive aspect is that it allows exploring different task solutions. Using a virtual throwing task [1], we examined how participants explore task solutions as they become more skilled. Naive subjects practiced 240 throws a day for 11 days - one group (N=13) had an easy target location and another (N=10) a difficult one. We hypothesized that participants in both groups would initially explore the task result space early in learning to find a solution and then fine-tune this solution over practice. We also hypothesized that once participants learn to reduce intrinsic noise, they would explore different solutions within the result space. Consistent with our hypothesis, participants in both groups found an initial task solution region. Only subjects in the easy target group, however, increased in variability to continue exploring the result space, as they were able to reduce their noise to a low level faster than the difficult target group. These results support the prior finding that participants initially seek most error-tolerant regions [1] and our hypothesis that exploration increases as expert participants reduce noise.
Simplified force field calculations of the low-frequency motions of the α-helix

Using valence force field constants and a highly simplified model of the α-helix consisting of only two masses per repeat unit we have been able to very nearly reproduce the low frequency phonon dispersion curves which we had obtained earlier with the use of a seven mass model and a Urey-Bradley force field. Since the frequencies obtained from this latter model agree well with the observed Raman frequencies it appears that the low frequency chain motions of polypeptide chains may be calculated from a very simple model involving the amino acid residues as essentially a single mass. Such techniques appear to offer the possibility of making normal mode calculations for the chain dynamics of polypeptide chains of low symmetry such as proteins.
Experiments on the Motion of Drops on a Horizontal Solid Surface due to a Wettability Gradient

Results from experiments performed on the motion of drops of tetraethylene glycol in a wettability gradient present on a silicon surface are reported and compared with predictions from a recently developed theoretical model. The gradient in wettability was formed by exposing strips cut from a silicon wafer to dodecyltrichlorosilane vapors. Video images of the drops captured during the experiments were subsequently analyzed for drop size and velocity as functions of position along the gradient. In separate experiments on the same strips, the static contact angle formed by small drops was measured and used to obtain the local wettability gradient to which a drop is subjected. The velocity of the drops was found to be a strong function of position along the gradient. A quasi-steady theoretical model that balances the local hydrodynamic resistance with the local driving force generally describes the observations; possible reasons for the remaining discrepancies are discussed. It is shown that a model in which the driving force is reduced to accommodate the hysteresis effect inferred from the data is able to remove most of the discrepancy between the observed and predicted velocities.
Teaching NeuroImages: Hyperdense posterior cerebral artery sign

A 38-year-old man presented to the emergency department with right-sided weakness, sensory loss, and hemianopsia. CT head showed a left hyperdense posterior cerebral artery sign (HPCAS) (figure 1). CT angiogram of the head confirmed a left posterior cerebral artery (PCA) occlusion (figure 2). MRI demonstrated a left PCA infarct. Transesophageal echocardiogram revealed an atrial septal aneurysm and patent foramen ovale. He was treated with antiplatelet therapy. The HPCAS has been considered a marker for acute ischemia in the PCA territory.1 Recognizing the HPCAS on CT in acute stroke may help in the diagnosis and treatment of thromboembolic PCA branch occlusion.
Immunochemistry of hybridomas

The attraction of monoclonal antibodies lies in the potential availability of an unlimited supply of material, homogeneity, reproducibility, and the feasibility of manipulation for specific purposes. Their use, however, is limited because of structural and physicochemical idiosyncrasies, occasionally restrictive factors influencing affinity and avidity, unique cross-reactivities, lack of multivalency compared to polyclonal antibodies, and restricted Fc region-specific functions. Approaches to the isolation, purification and fragmentation of monoclonal antibodies derive from basic concepts of the four chain and domain structure of immunoglobulins that have developed from the study of human M-components and a large number of well-characterized mouse myeloma proteins. The specific antibody activity used to generate the hybridoma provides an additional property that can be utilized to advantage in selecting clones and purifying material. Each monoclonal antibody is unique and presents its own set of problems affecting isolation, stability and suitability for chemical modification and radiolabeling. Isotypic determinants correlate with biological activities such as binding to staphylococcal protein A, Clq or specific Fc receptors, that may be important for purification and therapy. Analysis of fragmentation patterns obtained with various proteolytic enzymes [F(ab′)2, Fab, Fab′, Fab/c] can be related to accumulating protein and DNA sequence data. Fragments generated need to be defined for each hybridoma and may present additional idiosyncrasies. These include instability in standard solvents, poor reconstitutability following reduction, and loss of affinity for antigen. To some extent, idiosyncrasies reflect the idiotypic specificities of the antibody. Structural correlates of idiotypy include the binding site for a specific antigen (hypervariable regions), framework determinants, and conformational antigens that may be lost on varying pH, exposure to denaturants, or separation of heavy and light chains. In spite of these problems, however, fragments are more interesting therapeutically, as well as for the design of specific assays, because of loss of effector functions and the potential for artificial constructs. These properties have been exploited in the use of somatic mutants, transfectomas and hybrid molecules. Injection of such fragments to another species may bypass most (though not necessarily all) of the host response to isotypic and allotypic determinants, and still permit various anti-idiotypic antibodies to develop, only some of which may in fact interfere with antibody binding.
Critical Analysis: A Comparison of Critical Thinking Changes in Psychology and Philosophy Classes

This study compared changes in psychology and philosophy classes in two distinct components of critical thinking (CT): general skills and personal beliefs. Participants were 128 undergraduates enro...
Remarkable heterogeneity in meso‐ and bathypelagic bacterioplankton assemblage composition

We investigated meso- to bathypelagic (500–3,000 m) bacterioplankton assemblage composition at 19 locations in the North Atlantic Ocean beneath the offshore Amazon River plume, in the North Pacific Ocean near the Hawaiian archipelago, at the San Pedro Ocean Time Series (SPOTS) station off southern California, and in the Coral Sea off eastern Australia with a sensitive high-throughput fingerprinting approach, automated rRNA intergenic spacer analysis (ARISA), to examine variation between bacterial assemblages at different stations. Temperature and salinity were used to identify distinct water masses within gyres. ARISA fingerprints each contained 15–117 operational taxonomic units (OTUs) per assemblage; however, the OTU composition of fingerprints varied among stations, even within the same water mass. Fingerprints from 500 m at the SPOTS station over 4 yr shared on average a Sorensen Index (presence/absence similarity) of 0.68 6 0.01 and a Whittaker Index (proportional representation similarity) of 0.68 6 0.01, whereas at more oceanic stations at 500 m, fingerprints shared a Sorensen Index of 0.48 6 0.01 and a Whittaker Index of 0.38 6 0.01. At deeper depths (1,000 and 2,000 m), fingerprints were equally variable, sharing Sorensen Indices of 0.42 6 0.02 and 0.50 6 0.02 and Whittaker indices of 0.33 6 0.01 and 0.34 6 0.03, at 1,000 m and 3,000 m, respectively. Mesopelagic, moderately productive waters were more stable than those at less productive, open-ocean gyre stations, suggesting that variability in bacterioplankton communities at depth is influenced by organic matter supply and patchiness. Bacterioplankton in the world’s oceans are ecologically critical, processing typically 50% of primary production (Fuhrman and Azam 1982; Azam et al. 1983), comprising up to 70% of biomass in surface waters (Fuhrman et al. 1989), and mediating many global-scale nutrient transformations. Despite this, the richness and diversity of planktonic prokaryotic assemblages in the oceans have only recently been studied because of the advent of molecular techniques (Giovannoni et al. 1990; Fuhrman et al. 1992, 1993), which circumvent classical culture biases associated with .99% of bacterial taxa. These studies, and recent advances in molecular approaches to addressing
Understanding Leaders of Repressive Social Movements

Researchers studying right-wing authoritarianism (RWA) have discussed the need to distinguish authoritarian followers from leaders. Altemeyer's (2003) studies raise several issues about political leadership in the real world. First, are most leaders of authoritarian social movements high on both RWA and social dominance (SDO)? Second, is it possible to be an authoritarian leader of a repressive social movement without being high on SDO? Third, it would be useful to develop techniques to assess SDO at a distance. Fourth, what roles do the psychological motives of need for power, need for affiliation and intimacy, and need for responsibility play in motivating leadership behavior in high SDO leaders? Finally, does social dominance exist in countries with non–Western value systems? Understanding the psychology of leaders of repressive social movements may help us develop ways to limit access to the power they crave and to mitigate the damage that they do.
Associations of Mothers' Friendship Quality with Adolescents' Friendship Quality and Emotional Adjustment.

Little research has examined the association of parents' friendships with adolescent's well-being, perhaps because the association was considered too distal. However, developmental theories suggest that contexts in which parents, but not their children, are situated may be related to child development (Bronfenbrenner, 1979, 1986). The current work examined associations between the quality of mothers' own friendships and their adolescent children's friendship quality and emotional adjustment. Fifth-, eighth-, and eleventh-graders (N = 172) whose mothers' friendships were characterized by conflict and antagonism reported having friendships that were high in negative friendship qualities as well as elevated internalizing symptoms. These associations held after controlling for mother–child relationship quality, suggesting that mothers' friendships may have a unique association with adolescents' adjustment.