cssi/SciSciGPT-SciSciNet huggingface dataset:
The surface chemistry of acetone on a Pt foil

Abstract The adsorption, desorption and decomposition of acetone on a Pt foil have been studied by high resolution electron energy loss spectroscopy (HREELS), temperature programmed desorption (TPD) and Auger electron spectroscopy (AES). Two surface adsorption geometries occur for acetone on the foil: η 1 (O)-(CH 3 ) 2 CO (bonding end-on via the lone pair electrons on the oxygen) and η 2 (O,C)-(CH 3 ) 2 CO (bonding side-on via either π-bonding or di-σ bonding after rehybridization). For the η 1 species, reversible adsorption and desorption are dominant and are similar in behavior on a Pt(111) surface, while conversion of η 1 species to η 2 species may also occur. For the η 2 species, the decomposition channel is competitive with desorption, and the desorbed decomposition products are hydrogen and carbon monoxide. This process is associated with surface defects such as step sites, and preadsorbed hydrogen inhibits the decomposition channel thus providing additional support for this conclusion.
Steady state hydrogen transport in solids exposed to fusion reactor plasmas, part III: Isotope effects

Abstract A previously developed analytical transport parameter formalism for hydrogen transport is extended to include both intrinsic and synergistic isotope effects. Example calculations concentrate on the synergistic effects and show that a) competition for traps is normally a small effect, and b) cross isotope recombination at the surfaces leads to an increase in recycling while reducing both inventory and permeation for each of the participants.
Vessel detection in video with dynamic maritime background

Automating the detection of non-cooperative vessels in surveillance video is challenging. First, the detection algorithm has to handle a large degree of appearance variation of vessels with respect to shape, size and viewing geometry. Second, a unique challenge in the maritime domain is the presence of sea clutter, which can cause a high number of false detections. While recent research in object detection has largely been focused on objects on the ground, we have developed a layered detection algorithm to address challenges in the maritime domain by fusing cues from (1) a discriminative detection algorithm that learns a vessel target model from hundreds of vessel images, and (2) a dynamic texture-based background model that adaptively learns the spatiotemporal dynamics of sea clutter. We present results on how each layer of the algorithms was individually optimized, and how their outputs were fused. Initial results were promising showing a significantly lower false alarm rate than when only the target model was applied. The proposed approach has applications in port, coastal and waterway surveillance.
A comparison of the stimulatory effects of cadmium and zinc on normal and lead-inhibited human erythrocytic δ-aminolevulinic acid dehydratase activity in vitro

Abstract Zinc has been reported to activate δ-aminolevulinic acid dehydratase (ALAD) and to reverse lead-induced inhibition of human blood ALAD activity in vitro . Inasmuch as cadmium lies just below zinc in Group IIB of the periodic table of elements, similar studies were initiated with cadmium. Using normal adult human whole blood hemolysates, cadmium was found to activate normal erythrocytic ALAD and to reverse the in vitro lead-induced inhibition of ALAD at concentrations 40- to 100-fold lower than those of zinc. At higher concentrations cadmium was observed to inhibit erythrocytic ALAD activity, with a 50% inhibition of ALAD activity occurring at a concentration approximately 20 times higher than that of lead. The inhibition caused by cadmium, unlike that caused by lead, could not be reversed by an in vitro addition of zinc. The present results indicate that, with respect to concentration, cadmium is a more potent activator of normal adult human erythrocytic ALAD activity than is zinc. It is suggested that the role of cadmium and zinc in increasing ALAD activity and reversing lead induced inhibition of ALAD activity is a structural one related to binding of the metal to peripheral sulfhydryl groups.
Histone deacetylase expression patterns in developing murine optic nerve

Histone deacetylases (HDACs) play important roles in glial cell development and in disease states within multiple regions of the central nervous system. However, little is known about HDAC expression or function within the optic nerve. As a first step in understanding the role of HDACs in optic nerve, this study examines the spatio-temporal expression patterns of methylated histone 3 (K9), acetylated histone 3 (K18), and HDACs 1–6 and 8–11 in the developing murine optic nerve head. Using RT-qPCR, western blot and immunofluorescence, three stages were analyzed: embryonic day 16 (E16), when astrocyte precursors are found in the optic stalk, postnatal day 5 (P5), when immature astrocytes and oligodendrocytes are found throughout the optic nerve, and P30, when optic nerve astrocytes and oligodendrocytes are mature. Acetylated and methylated histone H3 immunoreactivity was co-localized in the nuclei of most SOX2 positive glia within the optic nerve head and adjacent optic nerve at all developmental stages. HDACs 1–11 were expressed in the optic nerve glial cells at all three stages of optic nerve development in the mouse, but showed temporal differences in overall levels and subcellular localization. HDACs 1 and 2 were predominantly nuclear throughout optic nerve development and glial cell maturation. HDACs 3, 5, 6, 8, and 11 were predominantly cytoplasmic, but showed nuclear localization in at least one stage of optic nerve development. HDACs 4, 9 and10 were predominantly cytoplasmic, with little to no nuclear expression at any time during the developmental stages examined. Our results showing that HDACs 1, 2, 3, 5, 6, 8, and 11 were each localized to the nuclei of SOX2 positive glia at some stages of optic nerve development and maturation and extend previous reports of HDAC expression in the aging optic nerve. These HDACs are candidates for further research to understand how chromatin remodeling through acetylation, deacetylation and methylation contributes to glial development as well as their injury response.
Direct synthesis of fluorinated peroxides. V. The preparation of pentafluorosulfurperoxy esters by reactions of pentafluorosulfur hydroperoxide with acyl fluorides

Abstract The reaction of SF 5 OOH with acyl fluorides in the presence of NaF has been investigated and found to yield new peroxy esters of the type RC(O)OOSF 5 . An alternate method of synthesis using SF 5 OOCl and acyl chlorides is discussed and the cesium fluoride catalyzed conversion of two of the esters to RCF(OF)OOSF 5 is described.
Mitral annular hinge motion contribution to changes in mitral septal–lateral dimension and annular area

Objective The mitral annulus is a dynamic, saddle-shaped structure consisting of fibrous and muscular regions. Normal physiologic mechanisms of annular motion are incompletely understood, and more complete characterization is needed to provide rational basis for annuloplasty ring design and to enhance clinical outcomes. Methods Seventeen sheep had radiopaque markers implanted; 16 around the annulus and 2 on middle anterior and posterior leaflet edges. Four-dimensional marker coordinates were acquired with biplanar videofluoroscopy at 60 Hz. Hinge angle was quantified between fibrous and muscular annular planes, with 0° defined at end diastole, to characterize its contribution to alterations in mitral septal–lateral dimension and 2-dimensional total annular area throughout the cardiac cycle. Results During isovolumic contraction (pre-ejection), hinge angle abruptly increased, reaching maximum (steepest saddle shape, change 18° ± 13°) at peak left ventricular pressure. During ejection, hinge angle did not change; it then decreased during early filling (change 2° ± 2°). Septal–lateral dimension and total area paralleled hinge angle dynamics and leaflet distance (anterior to posterior marker). Pre-ejection septal–lateral reduction was 13% ± 7% (3.3 ± 1.5 mm) from 9% muscular dimension fall and 18° ± 13° hinge angle increase. Conclusions Pre-ejection increase in hinge angle contributes substantially to septal–lateral and total area reduction, facilitating leaflet coaptation. Semirigid annuloplasty rings or partial bands may preserve hinge motion, but possible recurrent annular dilatation could result in recurrent mitral regurgitation. Long-term clinical studies are required to determine who might benefit most from preserving intrinsic hinge motion without compromising repair durability.
ANALYSIS OF NONLINEAR HUNTING VIBRATIONS OF RAIL VEHICLE TRUCKS

Truck hunting of rail freight vehicles is investigated on a tangent track with the car body moving at a certain constant forward velocity. The truck has three degrees of freedom in the lateral, yaw, and parallelogramming directions. The method of describing functions is employed for investigation of hunting. The three nonlinear differential equations of motion are thus converted to a set of six coupled nonlinear algebraic equations which are solved to obtain the values of the frequency, three amplitudes and two phase angles when hunting exists. It is shown that when hunting exists, the values of the frequency, amplitudes and phase angles are such that the energy input per cycle is exactly balanced by the energy dissipated. The orbital stability of limit cycles is investigated by employing the energy balance. The effects of the various parameters on hunting are investigated by parametric studies.
Gastric ulceration in rats induced by self-imposed immobilization or physical restraint.

Abstract Gastric ulceration was assessed in rats after they were placed in a self-immobilization condition in which the unrestrained animal could avoid footshock by remaining motionless. A second group received equivalent but unavoidable footshock which was not contingent on movement within the apparatus. A third group received no shock and served as a deprivation control. The first two groups showed a similar degree of ulceration which was greater than that observed in the deprivation control animals. Two methods of physical restraint were also yoked in series to the shock circuit of the self-imposed condition to assess the influence of different forms of restraint. The restraint via the legs plus shock condition produced a greater degree of ulceration than did whole body restraint plus shock. Heart rate and body weight changes were evaluated for each of the five conditions.
Numerical simulation of the disintegration of forced liquid jets using volume-of-fluid method

The present numerical study investigates the effect of finite sinusoidal velocity modulations imposed on an otherwise unperturbed cylindrical liquid jet issuing into stagnant gas using Volume-of-Fluid (VOF) methodology. Variation of the simulation parameters, comprising of the mean liquid jet velocity, modulation amplitude and frequency grouped together using a set of non-dimensional parameters, leads to the formation of a wide gamut of reproducible liquid structures such as surface waves, upstream/downstream directed bells and chains of droplets similar to those observed in experiments. The computations efficiently capture the diverse flow structures generated by the evolving modulated liquid jet inclusive of several nonlinear dynamics such as growth of surface waves, ligament interaction with shear vortices and its subsequent thinning process. The simulations identify the deterministic behaviour of modulated liquid jets to predict liquid disintegration modes under given set of non-dimensional parameters.
Simple derivations for two Jacobians of basic importance in multivariate statistics

Abstract Two very basic transformations in multivariate statistics are those of a p×q matrix X to a p×q matrix Y defined by Y = AXB (where A and B are matrices of constants) and of a p×p nonsingular matrix X to a p×p matrix W defined by W = X −1 . The Jacobians of these transformations are known to be | A | q | B | p and (−1) p | X | −2p , respectively, or | A | p+1 and (−1) p(p+1)/2 | X | −(p+1) , respectively, depending on whether X is unrestricted or X is symmetric and B = A ′ . The derivation of these formulas is greatly facilitated by the introduction of the vec and vech operators [H. Neudecker, J. Amer. Statist. Assoc. 64 (1969) 953–963; H.V. Henderson, S.R. Searle, Canad. J. Statist. 7 (1979) 65–81; J.R. Magnus, H. Neudecker, SIAM J. Algebraic Discrete Methods 1 (1980) 422-449; J.R. Magnus, H. Neudecker, Econometric Theory 2 (1986) 157–190]. Only relatively basic properties of these operators are needed. Arguments that appeal to the existence of the singular value decomposition or to related decompositions are not needed; nor is it necessary to introduce matrix differentials.
Mechanisms of interleukin-1-induced hormone secretion from the rat adrenal gland.

The aim of these studies was to determine the intraadrenal mechanism of interleukin-1 (IL-1)-induced corticosterone release from the rat adrenal gland. To accomplish this, the role of catecholamines and eicosanoids on IL-1-induced corticosterone release was determined. Experiments were conducted on primary cultures of dispersed rat adrenal cells. Dose-dependent increases (P<0.05) in corticosterone concentration were observed when primary adrenal cells were incubated with different doses (10−10 to 10−8 M) of IL-1α. CL-1α and IL-1β elevated corticosterone release after a 24 hr incubation period. ACTH elevated corticosterone levels at 4 and 24 hr. The stimulatory effect of IL-1 on corticosterone release was mimicked by epinephrine (1 μM), and was selectively blocked by the α-adrenergic antagonist, phentolamine (10 μM). The β-adrenergic antagonist, propranolol (10 μM), did not change IL-1 induced corticosterone release. Neither phentolamine nor propranolol had an effect on ACTH stimulated corticosterone relea...
Evolution of behavioural phenotypes: influences of ancestry and expression

Behavioural phenotypes are invariably plastic to some degree and are among the most labile of phenotypes. Some are acquired over the course of development in a particular environment (developmental plasticity), but most are elicited by an environmental trigger and are expressed only briefly, but often repeatedly, in the life of an organism (activational plasticity). Thus, individuals can possess the ability to perform a behaviour, but in the absence of the appropriate environmental stimulus, can fail to do so over the course of a lifetime. Rarely is the evolution of behavioural phenotypes explored in the larger context of the evolution of phenotypically plastic traits. Here I argue that the evolution of behavioural phenotypes, regardless of the nature of the plasticity expressed, can be examined in the same way as the evolution of other plastic traits. I first provide a conceptual review of the factors that can influence the evolution of plastic phenotypes and of the ways in which behavioural plasticity can influence the evolution of other aspects of phenotype. Many of the most compelling questions involve contrasting ancestral patterns of plasticity with those in derived populations or species, a particularly challenging problem in the case of phenotypic plasticity. I therefore provide an overview of the ways in which the influence of plasticity upon evolution can be addressed and then provide a review of examples from the literature that offer initial insights into the role of behavioural plasticity in evolution. The questions are exciting, the data limited, and, as I argue in closing, we need creative insights into the ways in which behavioural plasticity has evolved and has in turn influenced the evolution of other aspects of phenotype.
Manufacture of reduced fat Mozzarella cheese using ultrafiltered sweet buttermilk and homogenized cream.

Reduced fat Mozzarella cheese was manufactured from 0.5% fat milk that was standardized with unhomogenized or homogenized cream, from 0.5% fat milk with 3 or 5% ultrafiltered sweet buttermilk, or from ultrafiltered milk and homogenized cream. Curds were cheddared to a pH of 5.1 to 5.3, iced overnight, hand-stretched, brined for 10.5 h, vacuum-packaged, and stored at 4°C for 5 wk. The fat content in the cheeses ranged from 11.23 to 12.71%, and the moisture content ranged from 48.14 to 50.52%. The homogenization of the cream lowered the free oil content by 49%, and ultrafiltered buttermilk lowered it further. The percentage of free oil increased over time in all treatments. Homogenization of the cream did not affect the meltability of cheeses, but use of ultrafiltered buttermilk lowered meltability. Cheeses with 5% ultrafiltered buttermilk were the softest and had the highest scores for body and texture. Storage had no effect on hardness or on body and texture. Micrographs of cheeses from homogenized cream revealed many small fat globules. Cheeses with ultrafiltered buttermilk had a spongy and open protein matrix.
Hispanic-Serving Institutions and the Struggle for Cognitive Justice

Hispanic-Serving Institution (HSI) colleges and universities were initiated as an enterprise for investing in the academy as a way to provide opportunities for Latin@ students. However, HSIs in colleges and universities have had measured success in that significant numbers of Latin@ students continue to leave campuses with unfinished business. An inviting campus climate with well-prepared mentors, insightful administrators, and willing-to-help role models who are able to emphasize an education integrated with cultural funds could arguably augment the academic and social college lives of Latin@ students.
Environmental Fate and Effects of the Lampricide Bayluscide: a Review

Bayluscide is an additive to TFM that increases the effectiveness of TFM as a lampricide. A review of the literature was undertaken to determine the environmental fate and effects of Bayluscide. Niclosamide (2′, 5-dichloro-4′-nitrosalicylanilide), the active ingredient of Bayluscide, degrades rapidly in natural water and sediment systems, however, the rate of degradation is very slow in autoclaved samples. This difference suggests that degradation under laboratory conditions is dependent on microbial activity and hydrolysis plays a minor role in degradation of niclosamide. The major degradation product of niclosamide has been reported to be aminoniclosamide (2′,5-dichloro-4′-aminosalicylanilide), which represented more than 50% of the residues extractable from sediments. Significantly more of the chemical is adsorbed to sediments with higher organic content and at lower pH's. The mobility of niclosamide in soil can be characterized as slight to medium; the estimated leaching distance would range from 0 to > 25 cm depending on the soil type and pH. The active ingredient of Bayluscide (niclosamide) is decomposed by ultra-violet light depending on the intensity and duration of the exposure. The uptake of residues by most invertebrates exposed to 14C-niclosamide is fairly rapid and equilibrium is reached within 24 h. About 90% of the accumulated residues were lost within 48 h after the organisms were transferred to clean flowing water. As with invertebrates, fish rapidly accumulate and eliminate residues of niclosamide. Three distinct residues were isolated from the extracts of edible fillet tissue; parent niclosamide, the glucuronide conjugate of niclosamide, and the sulfate ester of niclosamide. Aquatic plants and agricultural crops do not appear to be adversely affected at concentrations of Bayluscide used for lamprey or snail control. Mayflies (Hexagenia sp.). tend to be susceptible to TFM, but are relatively resistant to the effects of exposure to Bayluscide. Bayluscide was originally developed as a molluscicide to eliminate snails. Therefore, it is not surprising that mollusks are extremely sensitive to Bayluscide. Oral, dermal, and ocular administration of Bayluscide to mammals resulted in no clinical signs of systemic toxicity. Tests of the chronic effects of Bayluscide indicated that it is not mutagenic or carcinogenic. Bayluscide is not persistent in the environment; it breaks down in natural water and sediment systems through hydrolysis, photolysis, and microbial degradation. Given the limited use and tight control maintained by the U.S. Fish and Wildlife Service during applications of lampricides, Bayluscide presents minimal risk to human health and safety of the environment.
Structure of an unusual sea urchin U1 RNA gene cluster.

Abstract Genomic clones containing multiple copies of the Lytechinus variegatus U1 gene have been isolated from a gene library in the phage λEMBL3. These clones contain both types of U1 RNA gene repeats interspersed in the same 15-kb fragment. In addition, about 1 3 of the repeat units contain a 260-bp insert 460 bp prior to the first nucleotide of the U1 RNA sequence. The inserted sequence is abundant in the sea urchin genome as judged by Southern blots of genomic DNA. There are no repeated sequences flanking the insert. The insert occurs at the same position in the highly conserved 5′ -flanking region at which a deletion has previously been reported.
Breaking the Bounds of Rationality: Values, Relationships, and Decision-making in Mexican Fishing Communities

In fishing communities in Baja California Sur, Mexico, fisheries management is heavily influenced by models of individual economic rationality held by biologists and others involved in management, in which fishermen 'choose' to overfish because they are motivated by selfish individual rationality. Yet there is much that is neglected by these models, including the pressures of economic markets, family and community expectations, and cultural and personal value systems. Actual decisions about fishing and resource management rarely match the expectations of classical or neoliberal economic models of individual behaviour. I argue here that rational choice theory is a historically and culturally constructed discourse that becomes a taken-for-granted lens for viewing behaviour around the world. The effects of this discourse can be seen in the policies that are derived from them, as shown through this case study.
Teaching cognitive processes: Software for laboratory instruction in memory and cognition

This paper describes a set of computer programs that allow students to participate as subjects in well-known experiments selected from the current literature on memory and cognition. The experiments address five major areas: levels of processing, encoding specificity, semantic memory, sentence-picture verification, and constructive processes in prose comprehension.
Fractal Geometry Surface Modeling and Measurement for Musical Cymbal Surface Texture Design and Rapid Manufacturing

This paper aims at an equation based simulation, CAD modeling and manufacturing of a fractal surface embedded on a musical cymbal. This study is a proof-of-concept of a new method of complex-surface characterization, design and manufacturing using an equation-based approach. A cymbal shape was chosen to carry the fractal profile because generally most musical cymbals have an inherent broken surface pattern that is created to enhance the resulting musical quality. A fractal surface cymbal model was developed; a point cloud representation of the cymbal was generated from Matlab; a surface model was built and processed in image data processing software Imageware; a solid model was completed in CAD software PRO/E; a rapid prototype of the fractal surface cymbal was fabricated; and MasterCam software was used to generate CNC codes and simulate the CNC machining process. The effect of the variation of the parameters of the equation based surface is also shown by varying the topothesy and fractal parameter of the surface.
Longitudinal brain magnetic resonance imaging study of the alcohol-preferring rat. Part I: adult brain growth.

Background: The alcohol-preferring (P) rat, a Wistar strain selectively bred to consume large amounts of alcohol voluntarily, has been used as an animal model of human alcoholism for 3 decades. Heretofore, knowledge about brain morphology has been confined to postmortem examination. Quantitative neuroimaging procedures make it feasible to examine the potential longitudinal effects of alcohol exposure in vivo, while controlling modifying factors, such as age, nutrition, and exercise. To date, few imaging studies have considered what morphological changes occur with age in the rodent brain, and none has systematically applied quantitative neuroimaging approaches to measure volume changes in regional brain structures over extended periods in the adult rat. Methods: We used structural magnetic resonance imaging (MRI) in a longitudinal design to examine 2 cohorts of adult P rats, never exposed to alcohol: Cohort A included 8 rats, 7 of which survived the entire study (578 days) and 4 MRI sessions; Cohort B included 9 rats, all of which survived the study (452 days) and 5 MRI sessions. Results: Growth in whole-brain volume reached maximal levels by about 450 days of age, whereas body weight continued its gain without asymptote. Growth was not uniform across the brain structures measured. Over the initial 12 months of the study, the corpus callosum area expanded 36%, cerebellum 17%, and hippocampus 10%, whereas ventricle size was unchanged. Factors affecting growth rate estimates included litter effects, MR image signal-to-noise ratio, and measurement error. Conclusion: Unlike longitudinal human reports of regional volume declines in aging brain tissue, several brain structures in adult rats continued growing, and some growth patterns were litter-dependent. Determining normal regional growth patterns of brain and of the substantial variance exerted by litter differences, even in selectively bred rats, is essential for establishing baselines against which normal and aberrant dynamic changes can be detected in animal models of aging and disease.
Matrix Riccati equations and systems structure

A new algorithm for solving discrete time linear-quadratic control problems is given. This algorithm is shown to be a special case of the "structure algorithm" used for characterizing properties of linear systems. It is also shown to be related to the Chandrasekhar-type equations recently introduced by Kailath.
The Multiwire Secondary Emission Monitor and the Emittance Measurement of the AGS Beam

For CBA injection the transverse emittances and the Twiss parameters of the AGS beam have to be well defined to minimize the phase space dilution in CBA. Although there exists a profile monitor device at U165, there are three reasons why construction of a multiwire profile monitor system at three locations from U500 to U168 is required. 1) The dispersion function is not zero at U165 which makes it harder to interpret the measurement. 2) The original single wire device takes five minutes to traverse the whole beam. 3) A three station multiwire system can provide the profile information at all locations in one pulse which makes on-line analysis possible. In summary, a set of three stations of Multiwire Secondary Emission Monitor (MSEM) has been built and installed in the fast external beam line for the measurement of beam profiles. Each unit consists of two planes each with 30 nickel wires having a diameter of 5 mils. The signal is linear within the range of 1010 to 1013 incident protons on the wire and the resolution of the signal is well within a few percent. A least-square fitting routine has been used to extract the emittance and phase space parameters of the beam. The emittances obtained at various intensities will help us to understand the AGS acceleration process and to choose the optimal injection scheme for CBA.
Effects of a series resistor on electron emission from a field emitter

Universal curves are constructed that provide an immediate determination of the effect of a series resistor on the electron emission from a field emitter. These curves are applicable to both the low current and high current regime. The effects of space charge and of the series resistor are apparent from these curves, which are applicable to a large class of materials. An example is given to illustrate their use.
The human side of radical innovation

Abstract Radical innovation requires organizations to move into unknown territory and experiment with new processes that largely elude systemization. In this paper we report on a 6-year longitudinal study of 12 radical innovation (RI) projects in 10 large established US based firms. In actuality, there are a number of organizational factors that leverage the human side of making radical innovation happen that, if viewed systematically, could be utilized more broadly for greater radical innovation success. We report on gaps and mismatches that emerged in the sample as well regarding the expectation for radical innovation to happen and the mechanisms by which people are incented to do so. We link our observations to the evolving dynamic capabilities literature as it is currently being extended into high velocity domains.
A comparison of ecosystem dynamics in freshwater wetlands

The effects of system closure on the dynamics of productivity and nutrient cycling are examined in four wetlands that differ in plant growth form and magnitudes and sources of water input and nutrient loading. Dynamics in relatively closed ombrotrophicCarex marsh andTaxodium swamp systems from Okefenokee Swamp are compared to those in open, rheotrophic riparian systems. The riparian systems examined includeZizaniopsis marshes along the tidal freshwater portion of the Altamaha River in Georgia and a matureTaxodium-Nyssa swamp along the Cache River in Illinois. Water budgets in the ombrotrophic systems are dominated by precipitation inputs while in the riparian wetlands they are dominated by overbank flooding. Nutrient loading to the open and closed systems differs by only two orders of magnitude, the former depending on atmospheric inputs and the latter depending on tidal and riverine inputs. Comparisons of nutrient import, export, and retention indicate that greater than 90% of inorganic nutrients are retained in the closed systems while less than 5% are retained in the open systems. Nutrient budgets for wetland vegetation, including aboveground uptake, root uptake, leaching, death, and translocation, are constructed. Strong differences in nutrient conservation within plant communities are found between marsh and forested closed systems and between open and closed systems as a whole. There is the indication that nutrients turn over more rapidly and nutrient cycles are less retentive and conservative as systems become more open and nutrient inputs increase. Nutrients turn over more rapidly in marshes with nonwoody vegetation than in swamp forests. This phenomena is partially attributable to the growth form of the vegetation as trees store vast amounts of high Canutrient ratio biomass in boles. Substituting space for time and marsh and swamp wetlands for young and mature ecosystems enables patterns of productivity and nutrient cycling for these wetlands to be compared with Odum’s (1969) predictions of ecosystem development. Patterns of ecosystem development in wetlands agree with those predicted for terrestrial systems in general, but there are many areas of contradiction. The degree of system closure appears to be a major factor controlling nutrient retention and cycling in wetland ecosystems. System closure is also likely to be important in determining the response of wetland systems to global increases in CO2 levels.
Structural characterization of the second major cross‐reactive idiotype group of human rheumatoid factors. Association with the VH4 Gene Family

Rheumatoid factors (RF) are the most common type of functional antibodies among naturally occurring human monoclonal IgM proteins. A large subset of these autoantibodies use structurally homologous light chains of the kappa III subgroup, which bear the 6B6.6 cross-reactive idiotype (CRI). Although antibody binding activity requires both heavy and light chains, information about the heavy chains used by these autoantibodies is limited. To investigate these proteins, the murine monoclonal antibodies, 5-14 and 6-10, were generated by immunization with the heavy chains of the 6B6.6 CRI-positive RF, COR and LEW. These antiidiotypic antibodies reacted with 8 of 11 autoantibodies that coexpressed the 6B6.6 CRI. All 8 RF had heavy chains from the VH4 gene family, as assessed by reactivity with a VH4-specific primary sequence-dependent antibody. The same RF were also identified by the previously described murine monoclonal antiidiotype, LC1. Further experiments revealed that the LC1 antibody delineates a subfamily of VH4 heavy chains that is preferentially used in kappa III-6B6.6 CRI-positive IgM-RF. The cumulative data suggest that 13-22% of RF express both the kappa III-6B6.6 and VH4-LC1 CRI. These findings document that RF autoantibody activity requires specific VL-VH pairing, and that a subset of idiotypically related VH4 heavy chains is commonly expressed in disease-associated monoclonal IgM-RF.
Enhanced reactivity of η1-allyl ligands in trialkylphosphite substituted CpFe(Co)2(η1-allyl) complexes

Abstract CpFe(CO) 2 (η 1 -ally) Ia and CpFe(CO) 2 (η 1 -methally) Ib undergo photochemically initiated carbonyl substitution by bicyclic phosphite III to give IIa and IIb respectively. These latter complexes are more readily protonated than CpFe(CO) 2 (η 1 -allyl) complexes and the resulting cationic olefin complexes V and VI are more stable to olefin ligand displacement than similar complexes of the parent system. Both IIa and IIb exhibit high thermal stability, in contrast to Ia or Ib. CpFe(CO) 2 (η 1 -2-butenyl) and CpFe(CO) 2 (η 1 -cyclopentyl) fail to undergo photochemically initiated CO substitution in the presence of phosphite III, but give instead the dinuclear complex Cp 2 Fe 2 (CO) 3 (L) (L = III). The complex CpFe(CO) 2 (η 1 -cyclopentenyl) (VIII) can, however, be prepared indirectly from IIb → VI → VII → VIII. Complex IIa is 900 times more reactive than Ia cycloaddition reaction with β,??-dicyanostyrene.
Continuous Measurement of Cerebral Cortical Blood Flow by Laser—Doppler Flowmetry in a Rat Stroke Model:

Laser-Doppler flowmetry (LDF), a new method allowing instantaneous, continuous, and noninvasive measurements of microcirculatory blood flow in a small tissue sample, was evaluated for its accuracy in monitoring regional cerebral blood flow (rCBF) in the cortical microcirculation after focal cerebral ischemia. Wistar and spontaneously hypertensive rats (SHR, n = 19) were subjected to permanent occlusion of the middle cerebral and common carotid arteries. Absolute rCBF in a tissue sample of the ischemic hemisphere was measured autoradiographically with [14C]iodoantipyrine as a tracer and compared to rCBF measured by LDF. Additionally, the percent change in rCBF between baseline and ischemic values was compared for both methods. Absolute rCBF values recorded with LDF correlated poorly (r = 0.54) with [14C]iodoantipyrine measurements. In contrast LDF readings expressed as a percentage of ischemic vs. preocclusion readings (relative LDF readings) correlated very well (r = 0.91) with the percent change in [14C]iodoantipyrine measurements. We conclude that LDF does not provide accurate measurements of absolute rCBF values but this method allows accurate measurements of changes in rCBF due to induction of focal cerebral ischemia.
SPINAL CORD ISCHEMIA REDUCES CALCIUM/CALMODULIN-DEPENDENT PROTEIN KINASE ACTIVITY

Calcium/calmodulin (Ca2+/CaM)-dependent protein phosphorylation was evaluated in a rabbit spinal cord ischemia model. One hour of ischemia reduced particulate (5% of control) and cytosolic (35% of control) Ca2+/CaM-dependent protein kinase activity significantly (p < 0.01). In vitro phosphorylation of endogenous proteins by endogenous Ca2+/CaM-dependent protein kinase showed that phosphorylation of 14 particulate and 7 cytosolic proteins was stimulated in the presence of Ca2+/CaM in control tissue. However, after 1 hour of ischemia, Ca2+/CaM-dependent protein phosphorylation was virtually absent in the particulate fraction and significantly reduced in the cytosol. When equal amounts of control and ischemic tissue samples were combined and assayed, Ca2+/CaM-dependent protein kinase activity was 43% of control in particulate and 70% of control in cytosolic fractions. This suggests that reduced Ca2+/CaM-dependent protein phosphorylation is probably not due to the presence of an inhibitory activity in ischemic tissue. These results show that the Ca2+/CaM-dependent protein phosphorylation system is impaired after ischemia durations which cause irreversible damage. These altered phosphorylation reactions may play critical roles in mediating irreversible neurologic injury.
Supersaturated dissolved oxygen measured by the phosphorescence decay rate

Abstract Unsaturated dissolved oxygen (DO) can be measured easily using oxygen probes based on electrochemistry. However, large concentrations of supersaturated dissolved oxygen are difficult to measure by traditional methods. We will introduce a new technique to measure supersaturated dissolved oxygen concentrations using the phosphorescence decay rate of a caged lumophore. The results are in good agreement with the Stern–Volmer equation, where the inverse of the lifetime is proportional to the dissolved oxygen concentration. We have demonstrated this technique by measuring dissolved oxygen concentrations from 0 to 10.9 mM (870% saturation).
Refining the Conceptual Framework of Enhancement

Several drugs, like Ritalin, Adderall, and Modafinil, can be used to enhance motivation in individuals with or without disease. Since these drugs increase attention, memory, and a host of other exe...
On medical management

Abstract To be successful, academic medical centers must exhibit leadership, a strong foundation in science and education, wide-ranging clinical experience, continuous innovation, exemplary service, and an earned reputation for consistently good results. (J Thorac Cardiovasc Surg 2001;121:S25-8)
Self‐leadership and performance outcomes: the mediating influence of self‐efficacy

A key foundation of empowering organizations is employee self-leadership. This study examines the effects of self-leadership skills and self-efficacy perceptions on performance. Structural equations modeling determined whether the influence of self-leadership on performance is mediated by self-efficacy perceptions. Results for the sample of 151 respondents indicated self-leadership strategies had a significant effect on self-efficacy evaluations, and self-efficacy directly affected performance. Further, self-efficacy perceptions were found to fully mediate the self-leadership/performance relationship. Theoretical and practical implications are discussed. © 1998 John Wiley & Sons, Ltd.
A market-driven approach to product family design

In an effort to meet the diverse needs of today's highly competitive global marketplace better, many companies are utilizing product families and platform-based product development to increase variety, shorten lead-times, and reduce costs. Current research in the area of product family design mostly focuses on the cost-savings benefits of the platform-based approach and does not sufficiently examine broader enterprise considerations such as profit and market share. Furthermore, very few existing design methods integrate market considerations (e.g., customer preferences, competition) with product development efforts in their formulation. In this work, in addition to integrating market considerations with traditional product family concerns (e.g., modular design, decisions regarding shared parts and processes), the scope of the product family design problem is expanded to include the product line positioning problem, i.e., the problem of determining the appropriate market niche for each product variant in t...
Discriminable textures with identical buffon needle statistics

A method is presented for generating pairs of textures for which the statistics of intersection with any collinear set of points placed at random on either texture are the same. The constraint that such "Buffon needle statistics" be identical is stronger than identity of second-order statistics. Nonetheless, many such texture pairs are effortlessly distinguishable. An example is given of such a texture pair, whose components are composed of either congruent ellipses or circles of various radii. The discriminability of such texture pairs implies that adequate models for human texture preception must contain local nonlinearities which receive input from non-collinear points.
Radial diffusion effects in a finite extravascular space surrounding a single capillary

Abstract An analysis is presented for transcapillary exchange as applied to the indicator-dilution technique. A single capillary is considered surrounded by a finite extravascular space in which the diffusion rate is finite in the radial direction. The outer boundary of the extravascular space is a semipermeable membrane representing a cell wall. The problem is solved for an arbitrary time, varying capillary input function by means of an eigenfunction expansion in the outer annulus, and a Laplace transformation in the capillary. The results indicate that the finite size of the extravascular space coupled with the finite diffusion rate have an appreciable effect on extraction. Comparisons with related theoretical work are indicated.
Hospital self-discharge among adults with sickle-cell disease (SCD): associations with trust and interpersonal experiences with care.

BACKGROUND—Patient self-discharge from hospitals has been associated with a number of negative clinical outcomes. Research suggests that low patient trust and poor quality interpersonal experiences with care may be associated with hospital self-discharge. Although adults with sickle cell disease (SCD) often report poorer quality healthcare experiences, research examining hospital self-discharge and its associations with both patient trust and quality of healthcare experiences is lacking for this patient population. OBJECTIVE—To examine the association of interpersonal experiences with care and trust in the medical profession with hospital self-discharge history among patients with SCD. DESIGN—Cross-sectional study. SETTING—A large, urban academic medical center. PATIENTS—Adults (age 18+) with SCD seeking outpatient or inpatient care. MEASUREMENTS—We compared patient characteristics, patient perceptions of the quality of interpersonal experiences with care, and levels of trust between patients with and without a history of hospital self-discharge. RESULTS—Adjusted analyses indicated that having a history of hospital self-discharge was associated with more negative interpersonal experiences and lower levels of trust. CONCLUSIONS—Hospital self-discharge may be an important indicator of the quality of care received by adults with SCD. Further research is needed to better understand this phenomenon so that effective interventions can be designed to prevent its occurrence.
A colony of rare Free-tailed Bats

A small crevice in a sheer cliff at 6200 feet elevation in the Chisos Mountains of Brewster County, Texas, houses the only colony of Tadarida macrotis (Gray) thus far discovered in the United States. The Chisos Mountains form a biological island separated from any other mountains by desert flats. The surrounding flats vary from 2000 to 3000 feet in elevation. The highest point of the Chisos Mountains is Emory Peak with an elevation of 7835 feet (U. S. Geological Survey Topographic Map, 1905). Above 5000 feet the characteristic species are mainly those of the Arid Transition life zone. The common trees are pinyon, juniper (at least three species), oak (several species), some yellow pine, Douglas fir, aspen, Arizona cypress, little-leaf maple, and madrone. Photographs illustrating the character of the flats surrounding the Chisos Mountains and the higher parts of these mountains are shown by Bailey (1905), plates 5 and 11 respectively. On May 7, 1937, my attention was drawn to the wall of a narrow canyon by the squeaking of bats. Climbing to the top of a steep talus slope I came to the base of a cliff composed of volcanic rock, in which the bat colony was located. About 40 feet above the top of the talus was a horizontal crack in the rock which appeared to be about 6 inches wide and 20 feet long. There was no possibility of reaching the crevice, so I resorted to a load of fine shot which brought down three specimens of Tadarida macrotis. Collections taken from various parts of the crevice indicated the colony was composed entirely of females, most of which were pregnant, and that no other species was present. At the base of the cliff lay a deposit of guano which extended the full length of the fracture. It was three to four feet wide, and in some places six inches deep. This indicated that the crevice had been occupied for at least several seasons. The droppings, samples of which were saved, are coarse in texture, light in color, and irregular in contour and shape. The larger ones are five to six millimeters long by two to three millimeters in diameter. The evening of the day on which the bats were discovered I stationed myself in the canyon a mile below the colony and stayed there until after dark. During this vigil I saw no bats which appeared to be the large free-tails. In order to determine the approximate number of bats in the colony and the time of leaving the roost I returned to the site the next evening before sunset. A pair of white-throated swifts flew repeatedly in and out of one end of the crevice, where apparently they were nesting. At intervals the bats did a great deal of squeaking, especially when the swifts flew past the main entrance of the fracture. At 7:40 P.M. Pipistrellus began to forage and as it became darker other small bats appeared, but it was not until 8:20 that 65
Map locations of barley Dhn genes determined by gene-specific PCR

We previously identified 11 unique barley Dhn genes and found, using wheat-barley addition lines, that these genes are dispersed on four chromosomes 3H, 4H, 5H, 6H. In the present work, more precise positions of barley Dhn genes were determined using gene-specific PCR and 100 doubled haploid lines developed from a cross of Dicktoo and Morex barley. Dhn10 is located on 3H between saflp106 and ABG4. Dhn6 is at the previously determined position on 4H between SOLPRO and BCD265a. Dhn1 and Dhn2 are at the previously determined position on 5H between mR and saflp172. The Dhn locus previously called Dhn4a on barley 5H or Dhn2.2 on T. monococcum 5A is in fact Dhn9 and maps to a revised position between BCD265b and saflp218. Dhn3, Dhn4, Dhn7 and Dhn5 each map to the same position on chromosome 6H, suggesting that the previously reported separation of Dhn3, Dhn4 and Dhn5 may reflect limitations in the accuracy of Southern blot data. In addition to clarifying the map positions of these important stress-related genes, these results illustrate the advantage of gene-specific probes for the mapping of individual genes in a multi-gene family.