cssi/SciSciGPT-SciSciNet huggingface dataset:
Degree Complexity of Birational Maps Related to Matrix Inversion

For a q × q matrix x = (x i, j) we let $${J(x)=(x_{i,j}^{-1})}$$ be the Hadamard inverse, which takes the reciprocal of the elements of x. We let $${I(x)=(x_{i,j})^{-1}}$$ denote the matrix inverse, and we define $${K=I\circ J}$$ to be the birational map obtained from the composition of these two involutions. We consider the iterates $${K^n=K\circ\cdots\circ K}$$ and determine the degree complexity of K, which is the exponential rate of degree growth $${\delta(K)=\lim_{n\to\infty}\left( deg(K^n) \right)^{1/n}}$$ of the degrees of the iterates. Earlier studies of this map were restricted to cyclic matrices, in which case K may be represented by a simpler map. Here we show that for general matrices the value of δ(K) is equal to the value conjectured by Angles d’Auriac, Maillard and Viallet.
Extraction of information content from stochastic disaggregation and bias corrected downscaled precipitation variables for crop simulation

We applied a simple statistical downscaling procedure for transforming daily global climate model (GCM) rainfall to the scale of an agricultural experimental station in Katumani, Kenya. The transformation made was two-fold. First, we corrected the rainfall frequency bias of the climate model by truncating its daily rainfall cumulative distribution into the station’s distribution based on a prescribed observed wet-day threshold. Then, we corrected the climate model rainfall intensity bias by mapping its truncated rainfall distribution into the station’s truncated distribution. Further improvements were made to the bias corrected GCM rainfall by linking it with a stochastic disaggregation scheme to correct the time structure problem inherent with daily GCM rainfall. Results of the simple and hybridized GCM downscaled precipitation variables (total, probability of occurrence, intensity and dry spell length) were linked with a crop model for a more objective evaluation of their performance using a non-linear measure based on mutual information based on entropy. This study is useful for the identification of both suitable downscaling technique as well as the effective precipitation variables for forecasting crop yields using GCM’s outputs which can be useful for addressing food security problems beforehand in critical basins around the world.
Seeing what Alzheimer saw.

The ability to visualize brain pathology in living individuals with Alzheimer disease could change how the disease is diagnosed and drugs to treat it tested. A recently developed positron emission tomography tracer helps to image fibrillar amyloid-β and neurofibrillary tangles and brings us closer to this goal.
Choroid plexus papilloma and meningioma: coincidental posterior fossa tumors: Case report and review of the literature

Abstract Objective We report an unusual case of an extraventricular choroid plexus papilloma (CPP) occupying the right ventral foramen magnum and lower right cerebellopontine angle (CPA), occurring together with a petro-tentorial meningioma. The clinical presentation, preoperative imaging, differential diagnosis, surgical treatment and histologic features of the two tumors are discussed. Case description The patient presented with a 2-month history of headache, altered facial sensation, dysphagia, and gait unsteadiness. Neurologic examination confirmed a wide-based, unsteady gait, hoarse voice, anisocoria, and partial right vocal cord paralysis. Diagnostic imaging demonstrated right petro-tentorial and right ventral foramen magnum lesions, both hyperintense on contrasted images and suggestive of meningiomas. A right suboccipital craniotomy and far lateral approach was used to resect both tumors. The petro-tentorial tumor was a histologically confirmed meningioma, but the ventral foramen magnum tumor was an extraventricular CPP. Conclusion This is a rare occurrence of concomitant meningioma and CPP. There is no known link between these two tumors. An exophytic 4th ventricular CPP must be considered in the differential diagnosis of a CPA or foramen magnum tumor.
Reporting concentration- and concentration ratio-de-pendent selectivity coefficients for ion-selctive electrodes

Abstract Occurrence and sources of concentration (activity)-dependent selectivity coefficients of ion-selective electrode responses have been interpreted on the bases of equilibrium or nonequilibrium conditions, mixed valence counter ion transport and failure of co-ion exclusion. Equilibrium conditions for common valence counter ions lead to apparent selectivity coefficients which depend only on activity ratios rather than on individual activities. Plots of Kpotij(app) vs. aj/ai, give unique response characterization. The importance of mixture responses for the determination of Kpotij (app) is emphasized. Examples of the two predicted types of response, e.g. apparent selectivity dependent on activity ratios or on individual activities, are illustrated by data for glass membranes.
Is literacy shared within households? Theory and evidence for Bangladesh

Abstract A member of a collective-action households may or may not share the benefits of literacy with others in that household; the shared gains from doing so may well be offset by a shift in the balance of power within the family. Using household survey data for Bangladesh, we find strong external effects of education on individual earnings. Holding a range of personal attributes constant, an illiterate adult earns significantly more in the non-farm economy when living in a family with at least one literate member. These effects are strongest, and most robust, for women. Omitted-variable bias cannot be ruled out but would also be consistent with an intra-household externality of literacy.
Cardiovascular disease in diabetic patients

Cardiovascular disease is the most frequent cause of morbidity and mortality in patients with diabetes. This article evaluates the results of clinical interventions that have been tested for their ability to ameliorate cardiovascular disease through identification and management of cardiovascular risk factors. These include hyperglycemia, insulin resistance, dyslipidemia, hypertension, cigarette smoking, and a procoagulant state. Attention to all cardiovascular risk factors is necessary if physicians are to reduce the burden of these complications in diabetic patients.
Chronic Hypoxia Impairs Cytochrome Oxidase Activity Via Oxidative Stress in Selected Fetal Guinea Pig Organs

We hypothesized that chronic hypoxia disrupts mitochondrial function via oxidative stress in fetal organs. Pregnant guinea pig sows were exposed to either normoxia or hypoxia (10.5% O2, 14 days) in the presence or absence of the antioxidant, N-acetylcysteine (NAC). Near-term anesthetized fetuses were delivered via hysterotomy, and fetal livers, hearts, lungs, and forebrains harvested. We quantified the effects of chronic hypoxia on cytochrome oxidase (CCO) activity and 2 factors known to regulate CCO activity: malondialdehyde (MDA) and CCO subunit 4 (COX4). Hypoxia increased the MDA levels in fetal liver, heart, and lung with a corresponding reduction in CCO activity, prevented by prenatal NAC. The COX4 expression paralleled CCO activity in fetal liver and lung, but was unaltered in fetal hearts due to hypoxia. Hypoxia reduced the brain COX4 expression despite having no effect on CCO activity. This study identifies the mitochondrion as an important target site in tissue-specific oxidative stress for the induction of fetal hypoxic injury.
Analysis of the T-cell receptor beta-chain variable-region (V beta) repertoire in monozygotic twins discordant for human immunodeficiency virus: evidence for perturbations of specific V beta segments in CD4+ T cells of the virus-positive twins.

Abstract We analyzed the T-cell receptor (TCR) V beta repertoire in human immunodeficiency virus type 1 (HIV-1)-infected individuals at different stages of disease. To circumvent the effect of HLA and other loci on the expressed TCR repertoire, we compared the TCR repertoire in nine pairs of monozygotic twins who were discordant for HIV infection. A semiquantitative polymerase chain reaction (PCR) assay and flow cytometry enabled us to show distinct differences in the V beta repertoire in the HIV-positive twin compared with the HIV-negative twin. By combining PCR and cytofluorometry, these differences were restricted to a specific set of TCR V beta segments, with members of the V beta 13 family perturbed in six out of seven cases and those of the V beta 21 family perturbed in four out of seven cases studied. Most of the other V beta families remained unchanged. Our results provide direct evidence for a skewed TCR repertoire in HIV infection.
Expression, purification, and characterization of thymidylate synthase from Lactococcus lactis

The thymidylate synthase (TS) gene from Lactococcus lactis has been highly expressed in Escherichia coli. The TS protein was purified by sequential chromatography on Q-Sepharose and phenyl-Sepharose. Six grams of cell pellet yielded 140 mg of homogeneous TS. TS is a highly conserved enzyme, and several of the conserved amino acid residues that have been implicated in catalytic function are altered in L. lactis TS. By use of a 3-dimensional homology model, we have predicted covariant changes that might compensate for these differences. With the large amounts of L. lactis TS now available, studies can be pursued to understand the structure-function relationships of this enzyme compared to other TSs and to confirm the presumed roles of the compensatory changes predicted in the homology model.
Polychromatic x-ray beam produced by a wiggler: A new dimension in x-ray diffraction at megabar pressures

The wiggler provides a substantially higher flux of photons through a given collimator at high energies than is available from the bending magnet at the Cornell High Energy Synchrotron Source. This opens a new dimension in ultrapressure x-ray diffraction studies. Examples are shown in which a good diffraction pattern of gold at 112 GPa (1.12 Mbar) was obtained in 13 s and in which the diffraction pattern for primitive hexagonal silicon at 35 GPa using the beam from the wiggler contains twice as many peaks as is the case for the beam from the bending magnet.
Consuming our way to greater well‐being: Theory and history

Keynes is widely accepted to have proved the existence of a consumption gap as a cause of economic depressions. Such a gap meant that, ironically, depressions could get worse as a result of the greater wealth produced by the modern economy, since, as Keynes argued, the wealthy consumed proportionately less than the lower‐income groups. Textual analysis, however, shows that Keynes's arguments amounted to assumptions, not demonstrations. And a survey of the empirical research of the subsequent half‐century reveals a lack of convincing evidence of the consumption gap.
Frameworks for amending reservoir water management

Abstract Managing water storage and withdrawals in many reservoirs requires establishing seasonal targets for water levels (i.e., rule curves) that are influenced by regional precipitation and diverse water demands. Rule curves are established as an attempt to balance various water needs such as flood control, irrigation, and environmental benefits such as fish and wildlife management. The processes and challenges associated with amending rule curves to balance multiuse needs are complicated and mostly unfamiliar to non-US Army Corps of Engineers (USACE) natural resource managers and to the public. To inform natural resource managers and the public we describe the policies and process involved in amending rule curves in USACE reservoirs, including 3 frameworks: a general investigation, a continuing authority program, and the water control plan. Our review suggests that water management in reservoirs can be amended, but generally a multitude of constraints and competing demands must be addressed before suc...
The Forest Investment Decision in a Time of Change

INCREASED capital expenditure by investors to intensify forest management is abetted by advances in harvesting techniques and utilization technology, but threatened by a growing concern for the natural environment. The take-off stage for forest investments is near. Domestically, industrial wood consumption appears to be on the verge of a sharp increase. The United States may soon become a net exporter of wood products. Concurrently the forest land base for timber production is shrinking. Increased investment is also favored by reductions in the risk of loss and greater accuracy in predicting the outcome of investments. Because of the extensive area of below par stands, investments will be common in timber stand improvement and type conversion. Timber stand improvement is attractive to investors because the cash outlay is minimal, the payoff period is short, and the rate of return is high. Type conversion, by contrast, requires a high cash outlay and has a long waiting period. Because of the high cost, high degree of technical sophistication, or both, these practices are sensitive to changing external factors. Some changes make investments more attractive. The advent of tree-length logging and largescale substitution of capital for labor in harvesting increase the unit value of stumpage and give managed stands a marketing advantage. Product value was increased by the breakthroughs in peeling southern pine for plywood and in pulping sawdust. Also, the adoption of high-speed, in-line sawing systems enhance labor productivity. Furthermore, the product possibilities of small logs has been expanded by the development of end and edge gluing for fabricating boards and overlays to upgrade them. Environmental concerns, on the contrary, could make forest practices more costly and difficult to execute and less effective. Prohibitions against chemical methods of cull tree and brush control could force the use of less efficient me-
A Linearised inverse problem for the wave equation

(1988). A Linearised inverse problem for the wave equation. Communications in Partial Differential Equations: Vol. 13, No. 5, pp. 573-601.
Calcium Isotopic Variations Produced by Biological, Kinetic, Radiogenic and Nucleosynthetic Processes

Study of the isotopic variations of calcium is of interest because Ca is important in geochemical and biochemical processes, and is one of few major cations in rocks and minerals with demonstrated isotopic variability. Calcium is critical to life and a major component of the global geochemical cycles that control climate. Studies to date show that biological processing of calcium produces significant isotopic fractionation (4 to 5‰ variation of the 44Ca/40Ca ratio has been observed). Calcium isotopic fractionation due to inorganic processing at high (e.g., magmatic) temperatures is small. There are few studies of calcium isotope fractionation behavior for low-temperature inorganic processes. The Ca isotopic variations observed in nature, both biological and inorganic, are mostly attributed to kinetic effects, but this inference cannot be confirmed until equilibrium Ca isotope fractionation is more thoroughly investigated. Evaporation of silicate liquids into vacuum at high temperature is expected to produce kinetic Ca isotopic fractionation, as is diffusion of calcium in silicate liquids and aqueous solutions. The evaporation effects have been observed in meteorite samples. Diffusion effects have been observed in the laboratory but not yet in natural samples. The potential value of Ca isotopic studies has barely been tapped. Improvements in measurement precision would increase the attractiveness of Ca isotopes as a geochemical tool, but such improvements have been slow in coming. Calcium is composed mainly of the isotope 40Ca, which is a highly stable, doubly magic nuclide (both the number of neutrons and the number of protons represent closed nuclear shells). There are a total of six stable isotopes covering a mass range from 40 to 48. Ca has been studied for isotopic variations in three ways. The major isotope, 40Ca is the primary radioactive decay product of radioactive 40K. About 89.5% of the 40K …
Effect of suspension on mouse bone microhardness

Antiorthostatic (hindlimb) suspension of mice results in a considerable reduction of bone formation at the femur mid-diaphysis. Comparisons with appropriate control groups indicate that this reduction is attributable to the unloading aspect of the model, and not to physiological stress or changes in feeding. Microhardness measurements of bone are used to provide information on site-specific mineralization and structural properties. The microhardness of femora formed during suspension is significantly less than that formed in the bone of control mice. These differences are observed both along the endocortical (11%) and periosteal (8%) perimeters. The microhardness of bone formed prior to the experimental period (“extant bone”) is not different in comparing suspended and control mice, and increased microhardness values for these areas are observed in comparison to baseline controls. Mice used to control for the physiological stress and feeding portions of the suspension model do not demonstrate reduced microhardness. Thus, the limb unloading effects of suspension, not the induced stress or feeding changes, cause a reduction in microhardness. As microhardness is positively related to mineralization in these bones, it appears that the reduced mineralization accompanying suspension unloading may contribute to compromised structural properties of the bone formed.
Controlling Inbreeding in Modern Breeding Programs

Modern livestock breeding programs feature accurate breeding value estimation and advanced reproductive technology. Such programs lead to rapid genetic progress, but they also lead to the accumulation of inbreeding via heavy impact of a few selected individuals or families. Inbreeding rates are accelerating in most species, and economic losses due to inbreeding depression in production, growth, health, and fertility are a serious concern. Most research has focused on preservation of rare breeds or maintenance of genetic diversity within closed nucleus breeding schemes. However, the apparently large population size of many livestock breeds is misleading, because inbreeding is primarily a function of selection intensity. Strategies for maintaining variation by restricting relationships between selected animals or by artificially increasing the emphasis on within-family information when estimating breeding values have been suggested, and some approaches seem to provide greater long-term responses than BLUP selection. Corrective mating programs are widely used in some species, and these can be modified to consider selection for economic merit adjusted for inbreeding depression. Selection of parents of AI bulls based on optimal genetic contributions to future generations, which are a function of estimated breeding values and genetic relationships between selected individuals, appears most promising. Rapid implementation of such procedures is necessary to avoid further reductions in effective population size. Missing pedigree information is a problem in practice, and the low net present value of future genetic gains makes it difficult for breeding companies to sacrifice short-term economic gains in favor of long-term diversity issues.
Ionically self-assembled second-order nonlinear optical thin film materials and devices

1Department ofElectrical Engineering, Virginia Tech, Blacksburg, VA 24061-03562Department of Physics, Virginia Tech, Blacksburg, VA 2406 1-0435AB STRACTWe report that a new ionically sell-assembled monolayer (ISAM) method for thin-filmdeposition can be employed to fabricate materials possessing the noncentrosymmetry that isrequired for a second order, x(2, nonlinear optical response. Using several differentcommercially-available polyelectrolytes and additional precursors designed and fabricated inour laboratories, we have produced ISAM nonlinear optical thin films with x(2 values greaterthan that of quartz. As a result of the ionic attraction between successive layers, the ISAM x(2films self-assemble into a noncentrosymmetric structure that has exhibited no measureabledecay of x(2 at room temperature over a period of more than four months. The x(2 of ISAMthin-films has been examined by second harmonic generation using a fundamental wavelengthof 1200 nm. The second harmonic intensity of the films exhibits the expected quadraticdependences of fundamental intensity and film thickness while the polarization dependence isconsistent with orientation of the chromophore dipole moment perpendicular to the substrate.We describe the potential application of such NLO thin-film materials in field sensing elementsand support instrumentation systems.Key words: ionicaily self-assembled monolayers, second harmonic generation, polar self-assembly, second order nonlinear optical susceptibifity, sensor devices
A development environment for the SSC control system

Abstract The SSC is developing a design environment for control system development within the context of EPICS. The environment is aimed at developers of applications using the EPICS Input/Output Controller (IOC). The unique aspect of this effort is our emphasis on providing a simple and intuitive development environment compared with tools currently available. Our most important goal in this effort has been to hide the complexity of EPICS IOC development from the developers. This paper describes two tools which are under development; The Function Block Editor (FBE) and the State Machine Editor (SME). The FBE provides a visual editing environment for graphically describing control processes as a set of related functional blocks. The configuration of functional blocks is then translated into IOC records and executed. SME allows the user to visually construct a sequence using a notation we are modeling after Grafcet [1]. State machines are translated into EPICS State Notation Language programs and executed. Future extensions will be described.
Determining functional/health status and its relation to disability in stroke survivors.

Determining the functional/health status of stroke survivors poses special difficulties because of cognitive impairments that frequently result from stroke. A possible means of assessing the status of stroke survivors who are cognitively impaired is getting proxy responses from a family member or other caregiver. Proxy agreement was evaluated for two measures of functional/health status, the Frenchay Activities Index (FAI) and the Health Status Questionnaire (HSQ), and a measure of disability, the Functional Independence Measure (FIM).Thirty-eight stroke survivors were administered the measures at follow-up (median time since the stroke, 6 months). Caregivers were instructed to answer as proxies for the stroke survivors in their care. Demographics on age, sex, race, marital status, educational level, side of lesion, and relation of stroke survivor to caregiver were collected.Proxy agreement was excellent for the FAI (intraclass correlation, .85) and the FIM (.87), but poor for the HSQ scales (average prox...
AUTHOR REPLY—An Unusual Case of Cardiac Amyloidosis

To the Editors:—We agree with Dr. Bucciarelli-Ducci that cardiovascular magnetic resonance (CMR) is a promising diagnostic test in patients with suspected cardiac involvement from systemic amyloidosis. Maceira et al.1 in their study of 29 patients with presumed cardiac amyloidosis found a characteristic pattern of global subendocardial enhancement of the left ventricle that was distinct from control patients with hypertensive cardiomyopathy. The study did not compare CMR to echocardiography to establish the diagnosis of cardiac amyloidosis but did suggest that CMR might provide a viable alternative noninvasive strategy for identifying cardiac amyloid patients. Perugini et al.2 performed a prospective analysis of 21 patients with biopsy proven AL amyloidosis or familial amyloidosis and found that 16 of their patients (76%) had abnormal gadolinium enhancement, although the distribution was more heterogeneous. It is interesting to note that the five patients without gadolinium enhancement all had both echocardiographic and histologic evidence of cardiac amyloidosis, suggesting that some patients will be missed if CMR is the only diagnostic test performed. Dr. Bucciarelli-Ducci et al.3 have elegantly demonstrated how CMR findings coupled with echocardiography and other clinical features of amyloidosis may obviate the need for endomyocardial biopsy in select patients. CMR may be able to detect patients with early myocardial involvement before they develop echocardiographic findings or clinical symptoms, although this has yet to be formally studied.4 It has also been suggested that CMR may be a useful noninvasive means to follow cardiac involvement in amyloid patients after treatment because echocardiography is limited in this regard.1 Dr. Bucciarelli-Ducci’s suggestion of using CMR to target areas for endomyocardial biopsy is also an intriguing application of this technique. As Dr. Bucciarelli-Ducci points out, CMR is not available at all centers as it requires experienced personnel to both administer and interpret the test. While its role has yet to be clearly defined, CMR is likely to become an important part of the armamentarium in the diagnosis and management of cardiac amyloidosis and should be considered as an adjunctive noninvasive test in patients with suspected amyloid myocardial deposition.
Flicker noise in triodes with positive grid

Abstract The noise in positive grid triodes is represented by two noise current generators i a and i g connected between cathode and grid and between cathode and anode, re-respectively. An accurate method for determining i a 2 , i g 2 and the correlation coefficient c = i a i g / i a 2 i g 2 ] 1 2 is proposed and carried out for several 6SN7 triodes. It is found that the noise generated at the cathode is distributed over the positive electrodes neither as the dc currents nor as the ac currents. The correlation coefficient c at low frequencies where flicker noise predominates is positive. Its magnitude can be accounted for by assuming that the electron beam, coming from a noisy spot on the cathode, has at the grid spread over a width comparable with or larger than the grid wire diameter; modulation of these electron beams can account for some details of the observations. The results are compatible with what is presently known about the flicker noise mechanisms operating in oxide-coated cathodes. The part of i a and i g that is uncorrelated with the noise generated at the cathode can be interpreted as a “partition flicker noise”.
Photometric lightcurves of 21 asteroids

Forty-three light curves of 21 asteroids obtained during 1968-1978 are presented and briefly discussed. The light curves were obtained to increase the data base for studies in shapes, spin periods, and the orientation of the rotation axes.
Electron spin resonance studies of the effects of sterilization on poly(ethylene glycol) hydrogels.

The effects of several sterilization procedures on a poly(ethylene glycol) (PEG) hydrogel have been examined by electron spin resonance (ESR) spectroscopy. The crosslinked polyurethanes were synthesized by reacting PEG with a tri-functional isocyanate. The free radical concentration of unsterilized, ethylene oxide (EtO), hydrogen peroxide (H2O2), and gamma sterilized hydrogels were monitored over time. Free radical presence was observed for all the treatments, unsterilized and sterilized PEG hydrogels. The unsterilized and the EtO sterilized samples elicited similar levels of free radical intensity whereas, the H2O2 and gamma sterilized samples had a significantly higher free radical concentration. The spectra reveal overlapping resonances of a peroxy and a triphenylmethyl radical. The concentration of the free radicals increase for all the treatments over time except for the gamma sterilized sample. The increase is significantly higher in the H2O2 sterilized sample. A tentative model is proposed to explain the reaction pathway leading to the production of the free radicals. The observed increases in the free radical concentrations of the EtO and hydrogen peroxide sterilized hydrogels over a five-month-period make it difficult to predict properties that are affected by free radical concentrations. In that light, gamma sterilization, that does not induce a change in free radical concentrations over a five month period, could be the sterilization method of choice for PEG hydrogels that could potentially be stored for undetermined periods of time prior to application. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Association Between Sex Partner Meeting Venues and Sexual Risk Taking Among Urban Adolescents

Abstract Purpose To increase understanding of the association between sexual partner meeting venue types (school, through friends or family, organized groups, public places, or on the street) and sexual risk taking among urban youths. Methods Data were from 17- to 18-year-old youths who reported having had sex (n = 1,656) by the time they participated in the 2008–2009 follow-up of a multicomponent alcohol preventive intervention, Project Northland Chicago. We used logistic regression to assess the association between partner meeting venue and sexual risk taking. Results Approximately 20% of Chicago adolescents met their most recent sex partner on the street or in public places. Adolescents who met their partner in a public place, rather than in school, were more likely to report having ≥3 years age-discordant partner (women: odds ratio [OR] = 7.7, 95% confidence interval [CI] = 3.3–17.7; men: OR=2.7, 95% CI=1.1–6.6], alcohol use before sex (women: OR=3.4, 95% CI=1.8–6.5; men: OR=2.4, 95% CI=1.3–4.4), casual partner (women: OR=not significant; men: OR=2.4, 95% CI=1.3–4.5), anal sex (women: OR=not significant; men: OR=2.4, 95% CI=1.2–4.9), and unprotected sex (women: OR=1.7, 95% CI=1.0–2.7; men: OR=1.9, 95% CI=1.1–3.4). Meeting partners on the street was associated with increased probability of alcohol use before sex (women: OR=2.2, 95% CI=1.1–4.3; men: OR=2.1, 95% CI=1.0–4.6), age-discordant partnerships among women (OR = 14.2, 95% CI=6.4–31.4), and casual sex partners among men (OR = 2.5, 95% CI=1.4–4.8). Conclusions Targeting sexual risk taking with partners selected from public places or the street may improve adolescent HIV preventive interventions.
Experimental determination of molar absorptivities and quantum yields for individual complexes of a labile metal in dilute solution

Although it is increasingly recognized that photochemical reactions of metal complexes can significantly affect the speciation and geochemical cycling of some metals in natural waters, progress has...
Effects of bacterial lipopolysaccharide on central monoamines and fever in the rat: involvement of the vagus.

Abstract Lipopolysaccharide (LPS) is known to produce a number of central and neuroendocrine effects but the mechanisms involved are still unclear. This study was done to investigate the possibility that LPS-induced fever and activation of central monoamines are mediated through the vagus. Adult male rats were subjected to sub-diaphragmatic vagotomy (SDV), or sham operation and treated with saline or LPS in saline (10 μg/kg bw) 2 h later. Rectal temperature was monitored at half-hourly intervals for 5 h after which the animals were sacrificed and monoamine concentrations in hypothalamic nuclei were measured using HPLC-EC. SDV delayed the rise in rectal temperature induced by LPS by 1 h when compared to Sham animals. It also increased the concentrations of monoamines in the paraventricular nucleus of both Sham and SDV rats. This indicates that routes other than the vagus probably mediate LPS’ actions on the central nervous system.
Caveolin-1 regulates chemokine receptor 5-mediated contribution of bone marrow-derived cells to dermal fibrosis.

In fibrotic diseases caveolin-1 underexpression in fibroblasts results in collagen overexpression and in monocytes leads to hypermigration. These profibrotic behaviors are blocked by the caveolin-1 scaffolding domain peptide (CSD) which compensates for caveolin-1 deficiency. Monocytes and fibroblasts are related in that monocytes are the progenitors of fibrocytes (CD45+/Collagen I+ cells) that, in turn, are the progenitors of many fibroblasts in fibrotic tissues. In an additional anti-fibrotic activity, CSD blocks monocyte differentiation into fibrocytes. We studied a mouse fibrosis model (Pump Model) involving systemic bleomycin delivery that closely models scleroderma (SSc) in several ways, the most important of which for this study is that fibrosis is observed in the lungs, skin, and internal organs. We show here that dermal thickness is increased 2-fold in the Pump Model and that this effect is almost completely blocked by CSD (p 80 % thinner. This effect is also blocked by CSD (p < 0.001). Even in mice receiving vehicle instead of bleomycin, CSD increases the thickness of the fat layer. To study the mechanisms of action of bleomycin and CSD, we examined the accumulation of the chemokine receptor CCR5 and its ligands MIP1α and MIP1β in fibrotic tissue and their roles in monocyte migration. Fibrocytes and other leukocytes expressing CCR5 and its ligands were present at high levels in the fibrotic dermis of SSc patients and Pump Model mice while CSD blocked their accumulation in mouse dermis. Migration toward CCR5 ligands of SSc monocytes and Pump Model bone marrow cells was 3-fold greater than cells from control subjects. This enhanced migration was almost completely blocked by CSD. These results suggest that low monocyte caveolin-1 promotes fibrosis by enhancing the recruitment of fibrocytes and their progenitors into affected tissue.
The imposition of, but not the propensity for, social subordination impairs exploratory behaviors and general cognitive abilities.

Imposed social subordination, such as that which accompanies physical defeat or alienation, has been associated with impaired cognitive function in both human and non-human animals. Here we examined whether domain-specific and/or domain-general learning abilities (c.f. general intelligence) are differentially influenced by the imposition of social subordination. Furthermore, we assessed whether the impact of subordination on cognitive abilities was the result of imposed subordination per se, or if it reflected deficits intrinsically expressed in subjects that are predisposed to subordination. Subordinate and dominant behaviors were assessed in two groups of CD-1 male mice. In one group (Imposed Stratification), social stratification was imposed (through persistent physical defeat in a colonized setting) prior to the determination of cognitive abilities, while in the second group (Innate Stratification), an assessment of social stratification was made after cognitive abilities had been quantified. Domain-specific learning abilities were measured as performance on individual learning tasks (odor discrimination, fear conditioning, spatial maze learning, passive avoidance, and egocentric navigation) while domain-general learning abilities were determined by subjects’ aggregate performance across the battery of learning tasks. We observed that the imposition of subordination prior to cognitive testing decreased exploratory tendencies, moderately impaired performance on individual learning tasks, and severely impaired general cognitive performance. However, similar impairments were not observed in subjects with a predisposition toward a subordinate phenotype (but which had not experienced physical defeat at the time of cognitive testing). Mere colonization, regardless of outcome (i.e., stratification), was associated with an increase in stress-induced serum corticosterone (CORT) levels, and thus CORT elevations were not themselves adequate to explain the effects of imposed stratification on cognitive abilities. These findings indicate that absent the imposition of subordination, individuals with subordinate tendencies do not express learning impairments. This observation could have important ramifications for individuals in environments where social stratification is prevalent (e.g., schools or workplace settings).
Determination of RNase A/2'-cytidine monophosphate binding affinity and enthalpy by a global fit of thermal unfolding curves.

Abstract A spectropolarimeter was used to measure the thermal response curves of RNase A in the presence and absence of the ligand cytidine 2′-monophosphate. A coupled equilibrium model was used to describe the dissociation of the protein–ligand complex (NL ⇄ N + L) and the thermal unfolding of the free protein (N ⇄ U). The unfolding curves of the protein in the presence of several different concentrations of ligand were fit to this coupled equilibrium model using global linkage analysis. The best-fitted values for the thermal unfolding of the apo-protein were 60.9 ± 0.2°C (Tm) and 105.5 ± 1.4 kcal/mol (ΔH), while the fitted values for the dissociation of the protein–ligand complex were 1.6 ± 0.4 μM (KD) and 18.7 ± 1.0 kcal mol−1 (ΔHL). These values were in excellent agreement with values obtained by other methods. The sensitivity of the data fitting was compared using linear or quadratic temperature dependence for the response curves of the free ligand (L), native apo-protein (N), native ligand–bound protein (NL), and unfolded apo-protein (U). There was no significant improvement in the precision of the fitted data when the temperature-dependent response for each species (N, L, NL, and U) was expressed as quadratic functions of temperature.
The disease-supporting capability of soils of different fungistatic capacity

(1986). The disease-supporting capability of soils of different fungistatic capacity. Canadian Journal of Plant Pathology: Vol. 8, No. 3, pp. 289-296.
In vitro rearing of Edovum puttleri, an egg parasitoid of the Colorado potato beetle, on artificial diets: Effects of insect cell line‐conditioned medium

Effects of conditioned media prepared from cell lines derived from 11 insect species (six families, three orders) on the in vitro growth and development of the egg parasitoid Edovum puttleri were investigated. The parasitoid exhibited significantly different responses to the various insect cell line-conditioned media that were incorporated into the artificial diets. When cell lines were derived from embryos, higher percentages of 3rd instars and prepupae were observed than when cell lines were derived from fat body or ovaries. Medium conditioned with cell line IPLB-CPB2 derived from the embryos of the Colorado potato beetle produced the best result. Preconditioning time was important. In general, 5 days of preconditioning appeared to be optimal. The growthand development-promoting effect may have resulted from growth factors or growth-supporting factors produced/ released by the insect cell lines into the culture medium. Upon storage at 04°C for 714 days, the ability of cell line-conditioned medium to promote development beyond the second instar was greatly reduced (approximately 1055%). Our studies demonstrated that to support the in vitro growth and development of E. puttleri, insect hemolymph could be successfully replaced with insect cell lineconditioned medium. These findings should facilitate the development of a cost-effective mass-rearing system for E. puttleri and/or other parasitoids. Arch. Insect Biochem. Physiol. 40:173182, 1999. Published 1999 Wiley-Liss, Inc.
Finding Mixed Cells in the Mixed Volume Computation

In practice, finding mixed cells in certain polyhedral subdivisions plays a dominating role when a polyhedral homotopy is employed to approximate all isolated zeros of polynomial systems. This paper gives a new algorithm for the mixed cell computation via a new formulation of the underlying linear programming problems. Numerical results show that the algorithm provides a major advance in the speed of computation with much less memory requirements.
Cycles in cannibalistic egg-larval interactions

A model of a cannibalistic larval-egg interaction such as occurs in Tribolium is developed which leads to a system of nonlinear Volterra integral equations. I determine the local stability properties of the unique equilibrium point of the model. A Hopf bifurcation analysis shows that the model always undergoes a subcritical bifurcation when stability is lost. Numerical solutions confirm the presence of multiple attractors over a range of parameter values. The form of the cycles observed in the numerical solutions is analogous to that observed in laboratory populations of Tribolium.
Timing of reproduction in a prairie legume: seasonal impacts of insects consuming flowers and seeds

Seasonal patterns of insect damage to reproductive tissue of the legume Baptisia australis were studied for three years in native tallgrass priairie. Contrasting seasonal patterns of damage were associated with the major species of insect consumers. The moth Grapholitha tristegana (Olethreutidae) and the weevil Tychius sordidus (Curculionidae), which together infested 80-100% of developing fruits (pods), consistently damaged more seeds on average in early than in late maturing pods. But while late opening flowers were less subject to attack from moths and weevils, they were more subject to attack from chewing insects, particularly blister beetles (Epicauta fabricii, Meloidae), which destroyed >80% of all flowers and developing young pods (including moth and weevil larval inhabitants). The blister beetles arrived late in the flowering season and fed particularly on young reproductive tissue, allowing larger, older pods that had developed from early opening flowers to escape destruction. The relative abundances and impacts of blister beetles, moths, and weevils varied from year to year. Adding to the uncertainty of reproductive success of the host plant were the large and variable amounts of damage to immature buds inflicted by insects (including the blister beetles and weevil adults) and late killing frosts. Thus, timing of flowering is critical to success in seed production for B. australis. The heavy impacts of insects and weather can result in a very narrow window in time (which shifts from year to year) during which B. australis can flower with any success. The opposing pressures exerted by insects and weather on floral reproductive success may act in concert with other features of the plant's biology to foster the maintenance of considerable diversity in flowering times among individuals in local populations of B. australis.
Collaborative Everyday Problem Solving: Interpersonal Relationships and Problem Dimensions

Older adults' preferred partners for collaborative everyday problem solving and the types of everyday problems solved alone and with others were examined in a sample of community dwelling older adults (N = 112, M age = 71.86 yrs., SD = 5.92 yrs.). Family members (i.e., spouses, adult children) were the most frequently nominated partners for collaborative everyday problem solving, but friends, neighbors, and church members also were nominated. Older adults reported that they solved numerous types of problems, including finance, house repair, and health, in collaboration with others. These problems were also prominent when older adults reported the problems that they consulted others for advice on how to solve and the problems they solved alone. Together the results suggest new directions for research on collaborative everyday problem solving in terms of the types of interpersonal relationships and problems to be investigated. Implications of the findings for researchers and practitioners are discussed in t...
Seagrass bed patchiness: effects on epifaunal communities in San Diego Bay, USA

Abstract Seagrass habitat structure influences epifaunal density, diversity, community composition and survival, but covariation of structural elements at multiple scales (e.g., shoot density or biomass per unit area, patch size, and patch configuration) can confound studies attempting to correlate habitat structure with ecological patterns and processes. In this study, we standardized simulated seagrass shoot density and bed area among artificial seagrass beds in San Diego Bay, California, USA to evaluate the singular effect of seagrass bed configuration (“patchiness”) on the density and diversity of seagrass epifauna. Artificial seagrass beds all were 1 m2, but were composed of a single large patch (“continuous” treatment), four smaller patches (“patchy” treatment), or 16 very small patches (“very patchy” treatment). We allowed epifauna to colonize beds for 1 month, and then sampled beds monthly over the next 3 months. Effects of seagrass bed patchiness on total epifaunal density and species-specific densities were highly variable among sampling dates, and there was no general trend for the effects of fragmentation on epifaunal densities to be positive or negative. Epifaunal diversity (measured as Simpson's index of diversity) was highest in very patchy or patchy beds on two out of the three sampling dates. Very patchy beds exhibited the highest dissimilarity in community composition in the first two sampling periods (August and September), but patchy beds exhibited the highest dissimilarity in the third sampling period (October). Our results indicate that seagrass patch configuration affects patterns of epifaunal density, diversity, and community composition in the absence of covarying bed area or structural complexity, and that patchy seagrass beds may be no less valuable as a habitat than are continuous seagrass beds. The spatial pattern employed when harvesting or planting seagrass may influence epifaunal habitat use and should be a key consideration in restoration plans.
Pyroelectric Materials: Scaling of Output Power With Dimensions and Substrate Clamping

An understanding of the power that can be harvested from pyroelectric materials and its dependence on material properties, geometry and boundary condition is crucial to the design of energy harvesting devices using these materials. In this paper, simple analytical expressions are developed for ideal voltage, power and power densities as a function of pyroelectric constant, permittivity, surface area, thickness, temperature variation and rate of change for unclamped samples. Experiments are performed to specifically study the effect of geometry and are compared with theoretical predictions.Copyright © 2009 by ASME
Tissue deposition and metabolism of 125I-labeled synthetic amino-terminal parathyroid hormone bPTH(1-34).

The tissue deposition and metabolism of125I-labeled synthetic amino-terminal parathyroid hormone, bPTH(1–34), were studied in rats. In comparison with the intact hormone molecule bPTH(1–84), the synthetic fragment was (a) cleared more rapidly from serum; (b) degraded more rapidly in peripheral tissues; (c) deposited to a greater extent in kidney; (d) deposited to a much smaller extent in liver. In bone, the accumulation of total radioactivity was approximately the same with both labeled hormones. The possible physiological significance of these patterns of distribution and metabolism is discussed.
Compensatory increase in lipogenic gene expression in adipose tissue of transgenic mice expressing constitutively active AMP-activated protein kinase-alpha1 in liver

Abstract We previously described a line of transgenic mice selectively expressing constitutively active AMPK-α1 under the control of liver-specific human apoE promoter with the hepatic control region sequence. In the short-term activation, the CA-AMPK-α1 transgenic mice at age 10–12 weeks exhibited normal hepatic triglyceride content as compared to wild-type mice due to compensatory increase in mRNA expression of genes in the cholesterol and fatty acid synthesis pathways. But it was not known whether the lipogenic gene expression in white adipose tissue also changed. Here we characterized mRNA expression profile of main lipogenic genes in the cholesterol and fatty acid biosynthesis pathway in white adipose tissue. The data show that short-term chronic activation of AMPK in liver caused marked compensatory increase in lipogenic gene expression both in liver due to induction of Srebp-2 and in white adipose tissue due to upregulation of Srebp-1c. These results support the notion that in addition to its well-recognized function for fat storage adipose tissue can play an adaptive role in fatty acid synthesis when fatty acid synthesis is severely reduced in liver, the main lipogenic organ in mammals.