cssi/SciSciGPT-SciSciNet huggingface dataset:
Geochemistry of tholeiites from Lanai, Hawaii

Lanai is the third smallest of the fifteen principal subaerial shield volcanoes of the Hawaiian hotspot. This volcano apparently became extinct during the shield-building stage of volcanism, as shown by the absence of both alkalic cap and post-erosional lavas. Major and trace element analyses of 22 new samples collected primarily from 3 stratigraphic sections show that Lanai tholeiites span a large range in composition. Some Lanai lavas are unique geochemically among Hawaiian tholeiites in having the lowest abundances of incompatible trace elements of any Hawaiian lavas and well-developed positive Eu anomalies. The geochemical characteristics of these low-abundance Lanai tholeiites are not the result of alteration, differences in mantle source modal mineralogy, the presence of residual accessory mantle phases or fractional crystallization of such phases, assimilation of depleted [MORB] wall-rock, or accumulation/resorption of phenocrysts or xenocrysts. Incompatible trace element ratios (e.g., Nb/La, Nb/Th, La/Th, La/Hf, Ce/Pb) in Lanai tholeiites span considerable ranges and form coherent trends with each other and with absolute abundances of these elements. Large variations in La/Sm, La/Yb, and absolute REE abundances at constant MgO suggest that Lanai tholeiites formed by variable amounts of partial melting. However, large ranges in incompatible element ratios cannot be explained solely by variations in partial melting of a geochemically homogeneous source, but must reflect geochemical heterogeneities in the Lanai source. Partial melting modeling indicates that the mixed Lanai source is probably LREE-enriched [i.e., (La/Yb)CN>1]. One component in the Lanai source, exemplified by the low-abundance tholeiites, has markedly lower REE/HFSE, Th/HFSE, alkali/HFSE, and Ce/Pb ratios than other Lanai or Hawaiian tholeiites and may indicate the presence of recycled residual subduction zone materials in the Hawaiian plume source. The positive Eu anomalies that characterize the low-abundance Lanai tholeiites are not the result of plagioclase accumulation or assimilation but are a feature of this source component. Progressive temporal geochemical variations in Lanai tholeiites from 2 stratigraphic sections indicate that the source composition of these lavas probably evolved over time. This change could have resulted from a progressive decrease in the extent of partial melting of the Lanai source. The compositional variability of Lanai tholeiites suggests that geochemical heterogeneities in their source are larger than the scale of partial melting. Lanai tholeiites could not have formed by smaller degrees of partial melting of plume material than did the larger-volume Hawaiian shields. Therefore, volume differences between Hawaiian shields must be controlled primarily by differences in the volume of supplied plume material rather than by differences in the degree of partial melting. The premature cessation of eruptive activity at Lanai may be attributed to relatively large degrees of partial melting of a small plume.
An unusual hyper-density in the middle ear of a pediatric patient on computed tomography scan §

Abstract We present a case of an unusual hyper-density noted on computed tomography (CT) scan within the middle ear of an 8-month-old female cleft palate patient seen in consultation for hearing loss. Premature infants commonly have developmental abnormalities. Various and numerous interventions are often necessary in the clinical work up. We report the case of a premature infant seen in consultation for hearing loss with an unusual hyper-density within the middle ear.
Investigation of the Iron−Sulfur Cluster in Mycobacterium tuberculosis APS Reductase: Implications for Substrate Binding and Catalysis†

The sulfur assimilation pathway is a key metabolic system in prokaryotes that is required for production of cysteine and cofactors such as coenzyme A. In the first step of the pathway, APS reductase catalyzes the reduction of adenosine 5'-phosphosulfate (APS) to adenosine 5'-phosphate (AMP) and sulfite with reducing equivalents from the protein cofactor, thioredoxin. The primary sequence of APS reductase is distinguished by a conserved iron-sulfur cluster motif, -CC-X( approximately )(80)-CXXC-. Of the sequence motifs that are associated with 4Fe-4S centers, the cysteine dyad is atypical and has generated discussion with respect to coordination as well as the cluster's larger functional significance. Herein, we have used biochemical, spectroscopic, and mass spectrometry analysis to investigate the iron-sulfur cluster and its role in the mechanism of Mycobacterium tuberculosis APS reductase. Site-directed mutagenesis of any cysteine residue within the conserved motif led to a loss of cluster with a concomitant loss in catalytic activity, while secondary structure was preserved. Studies of 4Fe-4S cluster stability and cysteine reactivity in the presence and absence of substrates, and in the free enzyme versus the covalent enzyme-intermediate (E-Cys-S-SO(3)(-)), suggest a structural rearrangement that occurs during the catalytic cycle. Taken together, these results demonstrate that the active site functionally communicates with the iron-sulfur cluster and also suggest a functional significance for the cysteine dyad in promoting site differentiation within the 4Fe-4S cluster.
Muscarinic receptor selectivities of 3-quinuclidinyl 8-xanthenecarboxylate (QNX) in rat brain

We have determined the binding of (R)-3-Quinuclidinyl 8-xanthenecarboxylate to muscarinic acetylcholine receptor preparations from rat cortex, hippocampus, caudate/putamen, thalamus, pons and colliculate bodies. The competition curves determined with [3H]quinuclidinyl benzilate as the radioligand are well described by a two site model with a difference in affinity between the two sites of 12-fold. The proportions of high affinity site vary from 100% in the caudate/putamen to 0% in the pons/medulla. The selectivities are different from those measured by pirenzepine and are consistent with QNX exhibiting similar affinity for the M1, M3, and M4 receptors with lower affinity for the M2 receptor. This assignment was confirmed by determining the affinities of QNX for the cloned receptor subtypes.
Signal, Noise and Resolution in Position-Sensitive Detectors

An analysis is presented of signal, noise and position resolution relations for some of the most interesting position-sensing methods. "Electronic cooling" of delay line terminations is introduced in order to reduce noise in the position-sensing with delay lines. A new method for terminating transmission lines and for "noiseless" damping which employs a capacitance in feedback is presented. It is shown that the position resolution for the charge division method with resistive electrodes is determined only by the electrode capacitance and not by the electrode resistance, if optimum filtering is used.
Tensile properties of candidate SNS target container materials after proton and neutron irradiation in the LANSCE accelerator

Abstract Tensile specimens of five austenitic stainless steels and two ferritic/martensitic (f/m) steels were irradiated under spallation conditions at temperatures between 60°C and 164°C to doses between 0.4 and 11 dpa. The irradiations were performed at the Los Alamos Neutron Science Center (LANSCE) accelerator in a beam of 800 MeV protons and in the mixed spectrum of protons and spallation neutrons from a tungsten target. Tensile testing was done at room temperature at a crosshead speed of 0.005 mm/s, corresponding to a strain rate of 10 −3 s −1 . All materials showed considerable irradiation hardening and loss of ductility. For EC316 LN stainless steel, which is the recommended material for construction of the spallation neutron source (SNS) mercury target container and shroud, the yield strength (0.2% offset) was increased by a factor of three at 11 dpa. This steel retained a significant uniform elongation of 6%, as did the other austenitic steels. The two f/m steels entered plastic instability failures at strains less than 1% for all doses.
Incidence of Listeria monocytogenes and Listeria spp. in a Small-Scale Mushroom Production Facility

Listeria monocytogenes is a foodborne pathogen of significant concern to the agricultural and food processing industry because of its ability to grow and persist in cool and moist environments and its association with listeriosis, a disease with a very high mortality rate. Although there have been no listeriosis outbreaks attributed to fresh mushrooms in the United States, retail surveys and recalls are evidence that L. monocytogenes contamination of mushrooms (Agaricus bisporus) can occur. The objective of this study was to determine the prevalence of Listeria spp., including L. monocytogenes, in a small-scale mushroom production facility on the campus of the Pennsylvania State University in the United States. Of 184 samples taken from five production zones within the facility, 29 (15.8%) samples were positive for Listeria spp. Among the Listeria spp. isolates, L. innocua was most prevalent (10.3%) followed by L. welshimeri (3.3%), L. monocytogenes (1.6%), and L. grayi (0.5%). L. monocytogenes was recovered only from the phase I raw material composting area. Isolates of L. monocytogenes were confirmed and serotyped by multiplex PCR. The epidemiological relatedness of the three L. monocytogenes isolates to those serotypes or lineages frequently encountered in listeriosis infections was determined by multi-virulence-locus sequence typing using six virulence genes, namely, prfA, inlB, inlC, dal, clpP, and lisR. The phylogenetic positions of the three isolates in the dendrogram prepared with data from other isolates of L. monocytogenes showed that all isolates were grouped with serotype 4a, lineage IIIA. To date, this serotype has rarely been reported in foodborne disease outbreaks.
Wavepacket approach to the cumulative reaction probability within the flux operator formalism

Expressions for the singular flux operator eigenfunctions and eigenvalues are given in terms of the Dirac delta-function representable as a localized Gaussian wavepacket. This functional form enables computation of the cumulative reaction probability N(E) from the wavepacket time-correlation functions. The Gaussian based form of the flux eigenfunctions, which is not tied to a finite basis of a quantum-mechanical calculation, is particularly useful for approximate calculation of N(E) with the trajectory based wavepacket propagation techniques. Numerical illustration is given for the Eckart barrier using the conventional quantum-mechanical propagation and the quantum trajectory dynamics with the approximate quantum potential. N(E) converges with respect to the Gaussian width parameter, and the convergence is faster at low energy. The approximate trajectory calculation overestimates tunneling in the low energy regime, but gives a significant improvement over the parabolic estimate of the tunneling probability.
Intestinal epithelial cell differentiation: new insights from mice, flies and nematodes

Decisions commonly made during development that affect proliferation, cell fate specification, differentiation, migration, and death are made repeatedly in the mouse small intestinal epithelium throughout adulthood. The results of these decisions are a stratification of proliferation, differentiation, and death along the mouse small intestine's crypt/villus axis. Recent genetic studies in Caenorhabditis elegans and Drosophila melanogaster have identified factors involved in determining cell fate and differentiation in gut endoderm. The stem cell hierarchy of the adult mouse intestinal epithelium makes it ideally suited for using chimeric animals to examine the functions of homologs of these lower eukaryotic (and other) proteins.
Shortcuts to making cardiomyocytes

The adult human heart lacks sufficient regenerative capacity to recover after a myocardial infarction. Cell-based therapy has emerged as a potential treatment for the failing heart; however, a key issue for the success of future cell-based therapies is the ability to obtain patient-specific high-quality cardiomyocytes in a fast and efficient manner. Recent progress has been made towards this goal using reprogramming-based approaches.
Structural insights for engineering binding proteins based on non-antibody scaffolds

Engineered binding proteins derived from non-antibody scaffolds constitute an increasingly prominent class of reagents in both research and therapeutic applications. The growing number of crystal structures of these 'alternative' scaffold-based binding proteins in complex with their targets illustrate the mechanisms of molecular recognition that are common among these systems and those unique to each. This information is useful for critically assessing and improving/expanding engineering strategies. Furthermore, the structural features of these synthetic proteins produced under tightly controlled, directed evolution deepen our understanding of the underlying principles governing molecular recognition.
Maxillary adaptation to expansion in the mixed dentition

This study presents the findings of 162 patients who underwent rapid maxillary expansion during the early mixed dentition. Maxillary changes were evaluated through the analysis of serial dental casts. Arch dimensions were measured pre-expansion, immediately post-expansion, and at yearly intervals until the eruption of the first premolars. The expansion was effected with an acrylic rapid maxillary expansion appliance bonded to the posterior teeth for 5 to 6 months. A simple retention protocol was used postexpansion. The average increase in transpalatal width was 5 to 6 mm. During the post-expansion period, most of the arch width increases were maintained. For example, 90.5% of the original expansion at the first permanent molars remained after the first year, with slightly less overall expansion (80.4%) evident at the end of the observation period (2.4 years postexpansion). Maxillary dental arches that initially were narrow tended to retain a greater percentage of the achieved expansion than those with initially wider arch dimensions. In addition, maxillae with initially more lingually-inclined molars tended to retain more expansion than maxillae with initially more facially-inclined molars. Palatal vault height decreased very slightly during treatment, but returned to pretreatment values one year after expansion and increased slightly during subsequent time intervals. The results of this study indicate that the majority of increased arch dimensions in patients produced by early orthopedic expansion of the maxilla are maintained at the end of the transitional dentition.
Impact of aberrant arterial anatomy and location of anastomosis on technical outcomes after liver transplantation

Variations in donor and recipient arterial anatomy frequently present challenges for surgeons when attempting to establish proper arterial inflow during liver transplantation. We reviewed our data on 233 adult primary liver transplants, conducted from January 1996 through December 2001, to determine the impact of these variations on the outcomes after liver transplantation. Twenty-four (10.3%) arterial complications were encountered at a mean of 2.27 months after transplant. Carrel patches for the anastomoses were not used in 33 patients (14%), which had no relation to arterial complications (P = 0.7). Sixty-one donors (26.2%) had at least one aberrant artery, which had no relation to arterial complications. However, use of donor celiac artery for anastomosis was significantly associated with higher arterial complications (16% versus other choices, P = 0.03). Furthermore, use of common hepatic recipient artery was associated with higher arterial complications (16%, P = 0.03). There were 58 total biliary complications (24.8%). Biliary complications were associated with the presence of arterial complications (P = 0.01). In conclusion, aberrant donor arterial anatomy was not associated with an increased rate of arterial complications; however, choice of location of arterial anastomosis may be a significant factor. Biliary complications were associated with arterial complications.
Chimeric DNA-RNA Hammerhead Ribozyme to Proliferating Cell Nuclear Antigen Reduces Stent-Induced Stenosis in a Porcine Coronary Model

Background —Stent-induced coronary restenosis is a major clinical and public health problem. Proliferating cell nuclear antigen (PCNA) is an important regulator of cell division, and blocking of its expression after angioplasty may limit intimal proliferation. Methods and Results —We cloned the porcine PCNA gene and constructed a chimeric hammerhead ribozyme to a segment of the gene with human homology. In vitro studies with both cultured porcine and human vascular smooth muscle cells demonstrated uptake of ribozyme within the nucleus and significant inhibition of cellular proliferation. The ribozyme was then delivered locally into pig coronaries in a stent model. At 30 days, histomorphometric analysis showed neointimal thickness of 0.51±0.20 mm in the ribozyme group versus 0.71±0.27 and 0.66±0.25 mm in stent controls and scrambled ribozyme control, respectively ( P =0.002, P =0.03). Quantitative angiographic analysis showed late loss of 1.4±0.5 mm for ribozyme versus 1.9±0.4 and 2.0±0.4 mm for the controls ( P =0.05 and P =0.02). Conclusions —Chimeric hammerhead ribozyme to PCNA inhibits smooth muscle cell proliferation in vitro and reduces both histomorphometric and angiographic restenosis in the porcine coronary stent model when delivered locally.
Regulation of Ribulose-1,5-Bisphosphate Carboxylase Activity in Response to Light Intensity and CO2 in the C3 Annuals Chenopodium album L. and Phaseolus vulgaris L.

The light and CO2 response of (a) photosynthesis, (b) the activation state and total catalytic efficiency (kcat) of ribulose-1,5-bisphosphate carboxylase (rubisco), and (c) the pool sizes of ribulose 1,5-bisphosphate, (RuBP), ATP, and ADP were studied in the C3 annuals Chenopodium album and Phaseolus vulgaris at 25°C. The initial slope of the photosynthetic CO2 response curve was dependent on light intensity at reduced light levels only (less than 450 micromoles per square meter per second in C. album and below 200 micromoles per square meter per second in P. vulgaris). Modeled simulations indicated that the initial slope of the CO2 response of photosynthesis exhibited light dependency when the rate of RuBP regeneration limited photosynthesis, but not when rubisco capacity limited photosynthesis. Measured observations closely matched modeled simulations. The activation state of rubisco was measured at three light intensities in C. album (1750, 550, and 150 micromoles per square meter per second) and at intercellular CO2 partial pressures (C1) between the CO2 compensation point and 500 microbars. Above a C1 of 120 microbars, the activation state of rubisco was light dependent. At light intensities of 550 and 1750 micromoles per square meter per second, it was also dependent on C1, decreasing as the C1 was elevated above 120 microbars at 550 micromoles per square meter per second and above 300 microbars at 1750 micromoles per square meter per second. The pool size of RuBP was independent of C1 only under conditions when the activation state of rubisco was dependent on C1. Otherwise, RuBP pool sizes increased as C1 was reduced. ATP pools in C. album tended to increase as C1 was reduced. In P. vulgaris, decreasing C1 at a subsaturating light intensity of 190 micromoles per square meter per second increased the activation state of rubisco but had little effect on the kcat. These results support modelled simulations of the rubisco response to light and CO2, where rubisco is assumed to be down-regulated when photosynthesis is limited by the rate of RuBP regeneration.
Mitochondrial encephalomyopathies: therapeutic approaches.

Therapy of mitochondrial encephalomyopathies (defined restrictively as defects of the mitochondrial respiratory chain) is woefully inadequate, despite great progress in our understanding of the molecular bases of these disorders. We review available and experimental therapeutic approaches, which fall into seven categories: (1) palliative therapy; (2) removal of noxious metabolites; (3) administration of artificial electron acceptors; (4) administration of metabolites and cofactors; (5) administration of oxygen radical scavengers; (6) gene therapy; and (7) genetic counselling. Progress in each of these approaches provides some glimmer of hope for the future, although much work remains to be done.
61 SEVERLY ILL PREMATURE INFANTS' MOTHERS' ATTITUDES

Previous investigations have demonstrated an increased sensitivity to the behavior of premature infants in the first 6 months of life. It has been assumed that this difference is a result of the mothers' experience of the infants' behavior after discharge. This study reports on the attitudes of mothers of preterm infants before hospital discharge. Twenty-two mothers of AGA preterm infants (28-32 weeks gestation) with medical complications completed the Cohler Maternal Attitude Scale, a 233 item Likert-type instrument, when their infants reached 34 weeks post-conceptional age. We examined 5 issues which assess attitudes towards maternal and infant attachment and infant separation. Scores were compared with Cohler's norms of 212 full-term uncomplicated deliveries. Two issues had elevated values: “period of reciprocal exchange”(2½-5 months,p< 0.01), and “period of early directed infant activity”(5-9 months,p < 0.02). There were no statistically significant differences in the three remaining issues (’focalization on the mother”, “widening reciprocity of interchange”, and “female sexuality”.) This suggests that mothers of ill prematures tend to be more sensitive to the infants' early efforts at stimulating and opening new areas of reciprocity with the mother, and that maternal attitudes toward premature infants are formed before hospital discharge of the baby.
Factors affecting the social validity of a role-play test of children's social skills

The social validity of a role-play test of children's social skills, the Social Skills Test for Children (SST-C), was evaluated by 63 subjects (33 adults and 30 children) who subjectively judged the quality of three children's role-play performances. The three children were selected as having high, medium, or low social skill based upon their performance on the SST-C. Assessment of the effects of subject characteristics upon judgments of social skill suggested that similarities in age and race between the subjects and the three children tended to diminish perceived differences in social skill among the three children. It was concluded that the social validity of the role-play test was supported only if the persons evaluating social behavior were dissimilar in age and racial characteristics from the persons who were being evaluated.
An oil import fee and drilling activity in the USA

Abstract M. King Hubbert's 1962 projections of US crude oil production outside Alaska are updated and the historical relationship between the number of rotary drilling rigs in operation in the USA and the real (hours per barrel) price of domestic crude oil is examined. The direct cost to consumers of a $5/bbl fee on imported oil is estimated to be about $30 billion per year or more than $1 623 000 per job that is likely to be created in the oil and gas industry.
Pretreatment EEG predicts short-term response to haloperidol treatment.

Abstract This study analyzed the relationship between pretreatment electroencephalogram (EEG) and response to haloperidol medication in a group of acutely exacerbated schizophrenic patients ( n = 34). Improvement was assesed after 3 and 6 weeks of treatment; it was measured globally, as decrease in the total score on the Brief Psychiatric Rating Scale (BPRS), as well as multidimensionally through the individual BPRS factors. Relative powers from four clinical EEG frequency bands were employed as predictor variables. Baseline alpha activity was significantly related to clinical response. Higher alpha values were associated with poorer response to treatment. Specifically, improvements on the "thought disturbance" and "hostility-suspiciousness" factors underlied the relationship between the pretreatment EEG and outcome.
RXRα-regulated liver SAMe and GSH levels influence susceptibility to alcohol-induced hepatotoxicity

Abstract Retinoids influence the pathogenesis of alcohol liver disease (ALD). To analyze the impact of retinoid X receptor alpha (RXRα) on ALD, alcohol-induced hepatotoxicity was studied using mice fed ethanol intragastrically for 25 days. Alcohol-induced microvesicular fat around the central vein and drug-induced morphological changes (loss of rough endoplasmic reticulum, pinkish cytoplasm, and enlarged hepatocyte) in the pericentral area were observed in the liver of wild-type mice. In the hepatocyte RXRα-deficient mouse liver, alcohol induced fat accumulation, mitosis, acute inflammation, and necrosis. The histology score after alcohol treatment was significantly higher in mutant mice than in wild-type mice. However, drug-induced morphological changes were not apparent in alcohol-treated hepatocyte RXRα-deficient mice. Northern analysis showed that the basal and alcohol-induced CYP2B, CYP2A, and CYP3A mRNA levels were lower in hepatocyte RXRα-deficient mice than in wild-type mice, which in turn may protect mutant mice from morphological changes. Compared with wild-type mice, hepatocyte RXRα-deficient mice have significant lower levels of S -adenosylmethionine and glutathione, which is further reduced after alcohol treatment, and that may account for severe liver injury induced by alcohol. The overall result suggests an important role of RXRα in preventing alcohol-induced liver injury.
Neurophysiological and Computational Principles of Cortical Rhythms in Cognition

Synchronous rhythms represent a core mechanism for sculpting temporal coordination of neural activity in the brain-wide network. This review focuses on oscillations in the cerebral cortex that occur during cognition, in alert behaving conditions. Over the last two decades, experimental and modeling work has made great strides in elucidating the detailed cellular and circuit basis of these rhythms, particularly gamma and theta rhythms. The underlying physiological mechanisms are diverse (ranging from resonance and pacemaker properties of single cells to multiple scenarios for population synchronization and wave propagation), but also exhibit unifying principles. A major conceptual advance was the realization that synaptic inhibition plays a fundamental role in rhythmogenesis, either in an interneuronal network or in a reciprocal excitatory-inhibitory loop. Computational functions of synchronous oscillations in cognition are still a matter of debate among systems neuroscientists, in part because the notion of regular oscillation seems to contradict the common observation that spiking discharges of individual neurons in the cortex are highly stochastic and far from being clocklike. However, recent findings have led to a framework that goes beyond the conventional theory of coupled oscillators and reconciles the apparent dichotomy between irregular single neuron activity and field potential oscillations. From this perspective, a plethora of studies will be reviewed on the involvement of long-distance neuronal coherence in cognitive functions such as multisensory integration, working memory, and selective attention. Finally, implications of abnormal neural synchronization are discussed as they relate to mental disorders like schizophrenia and autism.
Ribosomal DNA evidence for hybridization between island endemic species of Lotus

Abstract Restriction fragment analysis of nuclear ribosomal DNA was used to document the occurrence of hybridization on San Clemente Island between the rare Lotus scoparius ssp. traskiae and the more widespread L. argophyllus ssp. ornithopus . We detected four hybrids out of a total of 38 individuals examined from adjacent parental populations. Although the degree of hybridization is not extensive, it can still pose a threat to the long-term survival of L. scoparius ssp. traskiae through genetic assimilation by the more widespread L. argophyllus ssp. ornithopus , loss of a locally adapted population, and outbreeding depression.
A hybrid approach to estimate chromophoric dissolved organic matter in turbid estuaries from satellite measurements: A case study for Tampa Bay

Remote sensing of chromophoric dissolved organic matter (CDOM) from satellite measurements for estuaries has been problematic due to optical complexity of estuarine waters and uncertainties in satellite-derived remote sensing reflectance (Rrs, sr(-1)). Here we demonstrate a hybrid approach to combine empirical and semi-analytical algorithms to derive CDOM absorption coefficient at 443 nm (a(g)(443), m(-1)) in a turbid estuary (Tampa Bay) from MODIS Aqua (MODISA) and SeaWiFS measurements. The approach first used a validated empirical algorithm and a modified quasi-analytical algorithm (QAA) to derive chlorophyll-a concentration (Chla, mg m(-3)) and particulate backscattering coefficient at 443 nm (b(bp)(443), m(-1)), respectively, from which phytoplankton pigment and non-algal particulate absorption coefficient at 443 nm (a(ph)(443) and a(d)(443), m(-1)) were derived with pre-determined bio-optical relationships. Then, the modified QAA was used to estimate the total absorption coefficient at 443 nm (a(t)(443), m(-1)). Finally, a(g)(443) was estimated as (a(t)(443) - a(ph)(443) - a(d)(443) - a(w)(443)) where a(w)(443) is the absorption coefficient of pure water (a constant). Using data collected from 71 field stations and 33 near-concurrent satellite-field matchup data pairs covering a large dynamic range (0.3 - 8 m(-1)), the approach showed ~23% RMS uncertainties in retrieving a(g)(443) when in situ Rrs data (N = 71) were used. The same approach applied to satellite Rrs yielded much higher uncertainties of a(g)(443) (~85%) due to large errors in the satellite-retrieved Rrs(443). When the Rrs(443) was derived from the satellite-retrieved Rrs(550) and then used in the hybrid approach, uncertainties in the retrieved a(g)(443) reduced to ~30% (N = 33). Application of the approach to MODISA and SeaWiFS data led to a 15-year time series of monthly mean a(g)(443) distributions in Tampa Bay between 1998 and 2012. This time series showed significant seasonal and annual variations regulated mainly by river discharge. Testing of the approach over another turbid estuary (Chesapeake Bay, the largest estuary in the U.S.) demonstrated the potential (~25% uncertainties for a limited a(g)(443) range) of using this approach to establish long-term environmental data records (EDRs) of CDOM distributions in other estuaries with similar optical complexity.
Ligand-receptor interaction catalyzes the aggregation of small molecules to induce cell necroptosis

Because they exhibit important biological functions, from unfolding proteins to activating enzymes to controlling cell fates, aggregates of small molecules are able to serve as functional molecular entities in cellular environments. However, the inability to precisely control their production has hampered the understanding and exploration of their biological functions. Here we show that the well-established ligand-receptor interaction between vancomycin and d-Ala-d-Ala catalyzes the aggregation of a d-Ala-d-Ala-containing small peptide derivative in water. The resulting aggregates largely adhere to the cell surface to induce cell necroptosis. Mutation of d-Ala-d-Ala to l-Ala-l-Ala or removal of the aromatic group in the derivative results in innocuous compounds, confirming that the aromatic-aromatic and ligand-receptor interactions are responsible for the formation and corresponding cytotoxicity of the aggregates. In addition to being the first example of ligand-receptor interaction-catalyzed aggregation of small molecules on the surface of mammalian cells, this work provides useful insights for understanding the cytotoxicity of molecular aggregates of small molecules.
Recordings from the facial nucleus in the rat: signs of abnormal facial muscle response.

On the basis of results of electrophysiological studies in patients undergoing microvascular decompression (MVD) operations to relieve hemifacial spasm (HFS), we have postulated that the abnormal muscle response characteristically found in patients with HFS is the result of irritation of the facial nerve by the blood vessel that is compressing the facial nerve near its exit from the brainstem in these patients. This abnormal muscle response is seen when one branch of the facial nerve is electrically stimulated and recordings are made from muscles that are innervated by other branches of the facial nerve. We further hypothesized that the facial nucleus is hyperactive in patients with HFS and that the spasm and the abnormal muscle response are results of a phenomenon known as “kindling”. These hypotheses are supported by recent studies showing that chronic electrical stimulation of the facial nerve trunk in rats near the brainstem results in an abnormal muscle response that is similar to that seen in patients with HFS. In this paper, we present the results of recording from the facial motonucleus in rats that had been subjected to repeated electrical stimulation of the facial nerve. The results indicate that the abnormal muscle response in these rats was caused by changes in the function of the facial motonucleus. We interpret these results as showing that the physiological abnormalities that give rise to the signs of HFS in man are located in the facial motonucleus, and that the changes in the function of the nucleus are produced by chronic antidromic neural activity resulting from close contact between a blood vessel and the facial nerve.
Rational choice and the taxation of sin

Abstract The traditional literature on sumptuary taxation indicates that these taxes are the results of a majority of individuals imposing their moral code upon consumers of goods that are thought to be undesirable. Undoubtedly, this explanation is not trivial, and accounts for the existence of some of the present sumptuary taxes. This paper has developed a choice model of sumptuary taxes based on a wealth-maximization assumption that illustrates the possibility that an individual could approve of an excise tax on a good that he consumes.
Corn Seed Maturity Indicators and their Relationship to Uptake of Carbon‐14 Assimilate

Various maturity rating systems have been proposed to evaluate seed development in corn (Zea mays L.). The objective of this research was to determine the relationship of seed assimilate uptake and dry weigh to three indicators of physiological maturity: moisture concentration, black layer, and milk line development. Assimilate movement into the seed was determined by exposing the leaf subtending the ear to ¹⁴CO₂ at regular intervals during seed development and measuring the ¹⁴C 24 h later in F₂ seed of B73 ✕ Mo17 (1984, 1985) and the stay-green hybrids FS854 and Pioneer Brand 3358 (1985). In 1986 and 1987, plants of the same F₂ hybrids and the inbreds B73 and Mo17 and their F₁ cross (B73 ✕ Mo17) were defoliated at ≈20 d after pollination and seed development was compared to that of undefoliated plants. Seed dry weight, moisture concentration, and milk line and black layer development (using a five-stage rating system) were determined at 3- to 5-d intervals. Uptake of ¹⁴C-assimilate by seed and cob tissue decreased sharply near the end of the linear phase of seed dry weight accumulation when the milk line and black layer ratings were at Stage 3 (mid-milk line) greater. Near Stage 4 of both black layer and milk line development, ¹⁴C in the seed had fallen to the lowest levels, maximum seed weight had been reached, and the seed were physiologically mature. Both black layer and milk line followed consistent rends throughout seed development for all hybrids (including the stay-green genotypes), defoliation treatments, and years. Seed moisture during seed development was highly correlated with both black layer and milk line, but the concentration at black layer Stage 4 was more variable (293–415 g kg⁻¹) across genotypes and years. The data suggest that Stage 4 of both black layer and milk line development represents a useful and reliable indicator of physiological maturity. Contribution from Kentucky Agric. Exp. Stn. no. 90-3-47.
Seed morphology in New World Antirrhineae (Scrophulariaceae): systematic and phylogenetic implications.

Seeds of 39 species representing all native genera and sections of New WorldAntirrhineae were examined with the Scanning Electron Microscope and Light Microscope. Based on seed shape and surface ornamentation, seven morphological categories are recognized: cristate, tetracostate, foveolate, tumid tuberculate/cristate, circumalate, medusiform, and a miscellaneous category. Most sections and/or generic categories can be characterized by a single morphological type, althoughMaurandya s.l. has several distinctive seed types included within present generic boundaries. The cristate seed type is believed to be the “primitive type” from which the medusiform and tumid tuberculate/cristate types have developed. The tumid tuberculate/cristate type presumably gave rise to the circumalate, tetracostate, and foveolate patterns. The miscellaneous category (represented byLinaria andKickxia) may be phyletically remote from the other New World types. Seeds of the New WorldAntirrhineae mostly seem to be adapted for water dispersal although some adaptations for wind dispersal (e.g. wings, light weight) are evident. Free-hand sections and seed coat clearings indicate that circumalate seeds are of two different anatomical patterns; such structural diversity may be found in the other seed types.
Selling Liberia: Moss H. Kendrix, the Liberian Centennial Commission, and the Post-World War II Trade in Black Progress

This article examines the activities of Moss H. Kendrix, a budding black entrepreneur and Public Relations Officer for the Centennial Commission of the Republic of Liberia, during the years immediately following World War II. To secure US investment in Liberia’s postwar development, Kendrix re-presented African Americans and Americo-Liberians as new markets valuable to US economic growth and national security. This article argues that his tactics advanced the global significance of black peoples as modern consumers and his worth as a black markets specialist, while simultaneously legitimating notions of progress that frustrated black claims for unconditional self-determination or first-class citizenship. Kendrix’s public relations work on behalf of Liberia highlights intersections between postwar black entrepreneurialism and politics and US foreign relations, as well as the globalization of US business and consumerism.
MHC class II transactivator (CIITA) expression is upregulated in multiple myeloma cells by IFN-γ

The MHC class II transactivator (CIITA) acts in the cell nucleus as the master regulator of MHC class II (MHC II) gene expression. It is important to study CIITA regulation in multiple myeloma since MHC expression is central to ability of myeloma cells to present antigen and to the ability of the immune system to recognize and destroy this malignancy. Regulation of CIITA by IFN-gamma in B lymphocytes occurs through the CIITA type IV promoter (pIV), one of the four potential promoters (pI-pIV) of this gene. To investigate regulation of CIITA by IFN-gamma in multiple myeloma cells, first the ability of these cells to respond to IFN-gamma was examined. RT-PCR analyses show that IFN-gammaR1, the IFN-gamma-binding chain of the IFN-gamma receptor, is expressed in myeloma cells and IRF-1 expression increases in response to IFN-gamma treatment. Western blotting demonstrates that STAT1 is activated by phosphorylation in response to IFN-gamma. RT-PCR and functional promoter analyses show that IFN-gamma upregulates the activity of CIITA pIV, as does ectopic expression of IRF-1 or IRF-2. In vivo protein/DNA binding studies demonstrate protein binding at the GAS, E box and IRF-E sites. In vitro studies confirm the binding of IRF-1 and IRF-2 to CIITA pIV. Although multiple myeloma cells express PRDI-BF1/Blimp-1, a factor that represses both the CIITA type III and IV promoters, they retain the capability to upregulate CIITA pIV and MHC II expression in response to IFN-gamma treatment. These findings are the first to demonstrate that although PRDI-BF1/Blimp-1 diminishes the constitutive ability of these cells to present antigen by limiting CIITA and MHC II expression, it is possible to enhance this expression through the use of cytokines, like IFN-gamma.
An empirical development of critical value factors (CVF) of online learning activities: An application of activity theory and cognitive value theory

According to activity theory, activities are at the center of human behavior. Extensive attention has been given in literature to the success and effectiveness of online learning programs. Value theory suggests that human perceived value is a critical construct in investigating what is important to individuals. However, very limited attention has been given in literature to the role of users' perceived value of learning activities in educational settings. Scholars suggest that additional studies on learning activities are needed in order to progress the current knowledge of the use of information systems in education. Therefore, this study investigated issues related to learners' perceived value by uncovering the critical value factors (CVFs) of online learning activities. Participants in this study included 209 graduate students attending an online learning program. This study extended the first phase done in a prior research to uncover the CVFs of online learning activities. Results of this research study produced five reliable CVFs: (a) collaborative, social, and passive learning activities; (b) formal communication activities; (c) formal learning activities; (d) logistic activities; and (e) printing activities.
Isolation of massed- and distributed-practice items

In four experiments, massed-practice (MP) or distributed-practice (DP) items were isolated from other items in a list presented either visually or auditorially for free recall. For three independent groups, the first, second, or both presentations of an item were isolated. Locus of isolation had a marginal influence on recall. When MP items were isolated, they were recalled better than DP items. Isolating the DP items enhanced the MP-DP effect. The results are congruent with the idea that the MP-DP effect in free recall results, in part, from differential rehearsal.
Canonical representations of complex vibratory subsystems: time domain Dirichlet to Neumann maps

Large scale dynamic simulations can often be simplified by appropriately replacing large portions of the domain by a Dirichlet to Neumann, or DtN map (Givoli 1992. Numerical Methods for Problems on Infinite Domains, 1st ed. Elsevier, Amsterdam). Here we consider the problem of representing a linear dynamical subsystem by such a map. The exact DtN map is computed as a modal summation and its properties are studied. Bounds on the symbol of the DtN map in the Laplace domain are obtained. The exact map is then approximated, in particular in the high modal density regime. In the high modal density limit, we obtain the result that a subsystem can be accurately represented with just three parameters. Within such an approximation we obtain representations based on a maximum entropy representation, self-similar or fractal representation, and a rational function representation. The rational function representation leads to the interesting result that any complicated dynamical subsystem with a large number of degrees of freedom is asymptotically equivalent (in the limit of infinite modal density) to a single mass-dashpot-spring system. We end with numerical examples showing the efficiency of the rational function approximation.
Electrophoretic analysis of genetic variability in the apple

Abstract Starch gel electrophoresis using leaf tissue was employed to study 9 enzyme systems of the apple (Malus × domestica Borkh.); these were CAT, EST, G6PDH, MDH, SKDH, PGI, PGM, GOT and PER. Four enzyme systems (PGI, PGM, GOT and PER) exhibited some polymorphism and 3 loci, one each from PGM, GOT and PER enzyme systems, were identified and genetically analyzed using progeny tests from controlled crosses. PGM-1 had 2 alleles, Fast (F) and Slow (S), and was functional as a monomer; GOT-2 had 3 alleles, Fast (F), Medium (M) and Slow (S), and was active as a dimer; PER-2 had 5 alleles, a, b, c, d and e.
Topology in the Complex Plane

function theory." (In later editions, he did include a proof of part of this theorem, to illustrate the power of the concept of winding number for closed curves. It is worth mentioning that the notion of winding number is never used in this article.) It turns out that the basic facts about topology in R2 can be explained efficiently by identifying the real plane with the complex plane (also known as the complex line). The key advantages in this approach, as we shall see, come not only from the direct presence of multiplication, but most of all from the availability of the exponential function. The big disadvantage, of course, is that some of the proofs do not transfer to the study of topology in R' for n > 2. It is the purpose of this article to provide an exposition of this method, which was introduced by Eilenberg [4], and in particular to provide a fairly short proof of the Alexander duality theorem in the plane, and thus an easy proof of the Jordan curve theorem. The Alexander duality theorem in the plane is proved in Eilenberg's paper, which however is rather long, including as it does his doctoral thesis. It is also to be found proved by this method in Dieudonne's book [3]. I believe the argument presented here to be simpler. Since first submitting this article to the MONTHLY, I have discovered that the proof given here of Theorem 23, which I had proudly believed to be my discovery, had in fact been found many years ago by Graham Allan, though never published. The reader of this article is assumed to have a basic knowledge of point set topology, to know what a group is, and to have a slight acquaintance with complex numbers, in particular to know that ez = ex(cosy + i sin y) when z = x + iy with x and y real numbers. The brief final section assumes an acquaintance with sheaf theory and Cech cohomology.
Peripheral and intracerebroventricular administration of human chorionic gonadotropin alters several hippocampus-associated behaviors in cycling female rats

Our recent demonstration of receptors for luteinizing hormone (LH)/human chorionic gonadotropin (hCG) in rat brain with the highest density within the hippocampus and dentate gyrus suggests novel functional roles for gonadotropic hormones within the brain. The present study investigated whether 125I-hCG can cross the blood-brain barrier and reach hippocampus and the possible role of hCG in the regulation of several behavioral activities associated with the hippocampal formation in the rat. About 1/100th of peripherally injected 125I-hCG crossed the blood-brain barrier in an intact form and was found in cerebrospinal fluid and in hippocampus. Intraperitoneal (IP) or intracerebroventricular (ICV) injections of highly purified hCG on the morning of proestrus of cycling female rats resulted in changes in several hippocampus-associated behaviors. hCG-treated animals were generally less active and showed less exploratory behavior as compared to saline-injected control animals. There was no difference, however, in latency to enter the open field between hCG-treated and control animals. Taste neophobia was dramatically decreased following IP as well as ICV injection of hCG. No differences were found in the memory component of T-maze performance; however, the hCG-treated rats exhibited decreased stereotypic behavior. In summary, hCG can cross the blood-brain barrier, and peripheral or central administration of hCG affects several hippocampus-associated behaviors suggesting that hippocampal LH/hCG receptors are most likely involved in mediating these effects. Some of the observed behavioral changes have parallels in pregnant women.