cssi/SciSciGPT-SciSciNet huggingface dataset:
A Multi-Part Model Approach to Examining Medicaid Payment Methods and Nursing Home Quality

The incentive to provide nursing home quality depends, in part, on whether the state Medicaid reimbursement system is prospective or retrospective in nature. This paper examines the effect of state-level Medicaid reimbursement methods on the provision of quality in the context of bed constraint regulations that may influence market tightness. A three-part estimation strategy is constructed around the idea that a change in the Medicaid reimbursement method may affect both a facility's payer mix and the provision of quality. Across a range of quality measures, this multi-part model did not show nursing home quality to be significantly higher under a retrospective reimbursement system as compared with a prospective-based system of reimbursement. This finding holds regardless of whether the analysis was isolated to those markets with the tightest supply of beds or those homes that care for predominantly Medicaid residents.
Body Composition, Obesity, and Exercise

Obesity affects a large proportion of older adults, contributing to poor physical and mental health outcomes. Yet, weight loss (WL) interventions have been under-studied in this population due to concerns about exacerbating age-related reductions in muscle mass, bone density, and physical function. Thus, the potential influence of WL interventions on mental health and quality of life is mostly unknown. We assessed these attributes in a group of community-dwelling, obese (BMI ≥30 kg/m2) older adults (≥60 yr; n = 67) with mild to moderate physical impairment (SPPB score 4–10 out of 12) who were participating in a 6-month WL intervention (-500 kcal/day deficit; 2 diet groups [0.8 g versus 1.2 protein/kg body wt/day]). Significant weight loss and improved SPPB scores (ps < 0.05) were achieved by both groups. Mixed model analysis of the combined groups revealed short-term improvements in mental composite quality of life (SF-36), positive affect (CES-D), and total mood disturbance (POMS) at 3 months and sustained improvement of physical composite quality of life and its subdomains at both 3 and 6 months (ps < 0.05). Conversely, higher baseline depression (CES-D and POMS) and anger (POMS) and longer sleep latency (PSQI) were associated with less successful WL and blunted functional benefit. These findings demonstrate the potential benefits to mental health and quality of life of intentional WL in obese older adults and underscores the need for evaluation of mental health when considering a WL intervention for obese older adults.
Process modeling for slope and aspect with application to elevation data maps

Learning about the behavior of land surface gradients and, in particular, slope and aspect over a region from a dataset of levels obtained at a set of (possibly) irregularly spaced locations assumes importance in a variety of applications. A primary example considers digital terrain models for exploring roughness of land surfaces. In a geographic information system software package, gradient information is typically extracted from a digital elevation/terrain model (DEM/DTM), which usually presents the topography of the surface in terms of a set of pre-specified regular grid points, each with an assigned elevation value. That is, the DEM arises from preprocessing of an originally irregularly spaced set of elevation observations. Slope in one dimension is defined as “rise over run”. However, in two dimensions, at a given location, there is a rise over run in every direction. Then, the slope at the location is customarily taken as the maximum slope over all directions. It can be expressed as an angle whose tangent is the ratio of the rise to the run at the maximum. In practice, at each point of the grid, rise/run is obtained through comparison of the elevation at the point to that of a set of neighboring grid points, usually the eight compass neighbors, to find the maximum. Aspect is defined as the angular direction of maximum slope over the compass neighbors. We present a fully model-based approach for inference regarding slope and aspect. In particular, we define process versions of the slope and aspect over a continuous spatial domain. Modeling slopes takes us to directional derivative processes; modeling angles takes us to spatial processes for angular data. Using a stationary Gaussian process model for the elevation data, we obtain distribution theory for slope and associated aspect as well as covariance structure. Hierarchical models emerge; fitting in a Bayesian framework enables attachment of uncertainty. We illustrate with both a simulation example and a real data example using elevations from a collection of monitoring station locations in South Africa.
Chronic contact with realistic soil concentrations of imidacloprid affects the mass, immature development speed, and adult longevity of solitary bees

The non-target effects of pesticides are an area of growing concern, particularly for ecologically and economically important organisms such as bees. Much of the previous research on the effects of neonicotinoids, a class of insecticide that has gained attention for non-target effects, on bees focused on the consumption of contaminated food resources by a limited number of eusocial species. However, neonicotinoids are known to accumulate and persist in soils at concentrations 2 to 60 times greater than in food resources, and may represent an important route of exposure for diverse and ecologically important ground-nesting bees. This study aimed to assess the effect of chronic contact exposure to realistic soil concentrations of imidacloprid, the most widely used neonicotinoid pesticide, on bee longevity, development speed, and body mass. Cohorts of Osmia lignaria and Megachile rotundata were used as proxies for ground-nesting species. We observed species- and sex-specific changes to adult longevity, development speed, and mass in response to increasing concentrations of imidacloprid. These results suggest that chronic exposure to nesting substrates contaminated with neonicotinoids may represent an important route of exposure that could have considerable physiological and ecological consequences for bees and plant-pollinator interactions.
Predicted changes in abortion access and incidence in a post-Roe world.

Abstract Objective To examine changes in travel distance and abortion incidence if Roe v. Wade were reversed or if abortion were further restricted. Study Design We used a national database of abortion facilities to calculate travel distances from the population centroids of United States counties to the nearest publicly-identifiable abortion facility. We then estimated these travel distances under two hypothetical post-Roe scenarios. In the first, abortion becomes illegal in 8 states with preemptive “trigger bans.” In the second, abortion becomes illegal in an additional 13 states classified as at high risk of outlawing abortions under most circumstances. Using previously-published estimates of the short-run causal effects of increases in travel distances on abortion rates in Texas, we estimate changes in abortion incidence under each scenario. Results If Roe were reversed and all high-risk states banned abortion, 39% of the national population of women aged 15-44 would experience increases in travel distances ranging from less than 1 mile to 791 miles. If these women respond similarly to travel distances as Texas women, county-level abortion rates would fall by amounts ranging from less than 1% to more than 40%. Aggregating across all affected regions, the average resident is expected to experience a 249 mile increase in travel distance, and the abortion rate is predicted to fall by 32.8% (95% confidence interval 25.9 to 39.6%) in the year following a Roe reversal. Conclusion In the year following a reversal, increases in travel distances are predicted to prevent 93,546 to 143,561 women from accessing abortion care. Implications A reversal or weakening of Roe is likely to increase spatial disparities in abortion access. This could translate to a reduction in abortion rates and an increase in unwanted births and self-managed abortions.
Inhibition of glycolysis: Novel therapy for ovarian cancer

3085 Objectives: Resveratrol (3,5,4’-trihydroxystilbene), a natural phytoalexin found in red wine, grapes, and other dietary sources, has anti-neoplastic activity. We have previously demonstrated that resveratrol induces autophagic cell death (type II programmed cell death) in ovarian cancer cells. Autophagy is induced in mammalian cells in response to amino acid or glucose deprivation. Cancer cells exhibit increased rates of glycolysis as compared to normal cells, and have increased susceptibility to cell death induced by glucose deprivation. The purpose of this study was to determine if resveratrol induced autophagy in ovarian cancer cells is due to inhibition of glucose uptake, and to determine the therapeutic effect of resveratrol in vivo. Methods: Eight ovarian cancer cell lines were incubated with media containing glucose, resveratrol, or 2-deoxyglucose (2-DOG). Growth inhibition was determined using the sulforhodamine assay. Glucose uptake was analyzed with the 3H-2-DOG assay. Activation of AKT and translocation of the Glut1 receptor was determined by immunoblotting. A bioluminescent ovarian cancer xenograft model was used to determine the effect of resveratrol in vivo. A2780 ovarian cancer cells stably expressing green fluorescent protein were injected into the peritoneal cavity of female nu/nu mice. After tumor establishment, mice were treated with vehicle control, cisplatin, or resveratrol. Tumor response was monitored on a light box. Results: Glucose deprivation and resveratrol induced cell death in all ovarian cell lines by 24 h. Resveratrol inhibited glucose uptake, AKT activation and translocation of the Glut1 receptor to the plasma membrane. Mice treated with cisplatin and resveratrol had a complete response to treatment, whereas control mice developed carcinomatosis. Conclusions: Resveratrol inhibits glucose uptake in ovarian cancer cells and induces autophagocytosis. The majority of conventional chemotherapeutic agents induce apoptotic cell death. Because resveratrol can circumvent chemoresistance due to alterations in apoptotic signaling, it has the potential to be effective against chemoresistant disease. Furthermore, because ovarian cancer cells are dependent upon glucose for survival, agents that inhibit glycolysis, such as resveratrol, may have significant therapeutic benefit for ovarian cancer patients.
Stereocilia Rootlets: Actin-Based Structures That Are Essential for Structural Stability of the Hair Bundle.

Sensory hair cells of the inner ear rely on the hair bundle, a cluster of actin-filled stereocilia, to transduce auditory and vestibular stimuli into electrical impulses. Because they are long and thin projections, stereocilia are most prone to damage at the point where they insert into the hair cell’s soma. Moreover, this is the site of stereocilia pivoting, the mechanical movement that induces transduction, which additionally weakens this area mechanically. To bolster this fragile area, hair cells construct a dense core called the rootlet at the base of each stereocilium, which extends down into the actin meshwork of the cuticular plate and firmly anchors the stereocilium. Rootlets are constructed with tightly packed actin filaments that extend from stereocilia actin filaments which are wrapped with TRIOBP; in addition, many other proteins contribute to the rootlet and its associated structures. Rootlets allow stereocilia to sustain innumerable deflections over their lifetimes and exemplify the unique manner in which sensory hair cells exploit actin and its associated proteins to carry out the function of mechanotransduction.
Stability of Floating Ice Blocks

The critical conditions at which buoyant blocks on a flowing stream are swept under a downstream floating cover are investigated analytically and experimentally. The mathematical model of block stability is based on a one-dimensional hydrodynamic analysis of the flow passing beneath the upstream end of a floating cover, and the force and moment equilibrium of the block. It is argued that the condition of incipient submergence is reached when the block sinks and rotates until the stagnation water surface elevation equals that of the top upstream edge of the block. Experiments to verify the analysis were conducted in a 1-ft wide laboratory flume using right parallelpiped blocks with three different specific gravities and a range of length-thickness ratios. The moment coefficient which arises in the analysis was evaluated by means of the experimental data, which were found to be in good agreement with the analytical results.
Chapter 25 – Neural Basis of Speech Perception

The functional neuroanatomy of speech processing has been difficult to characterize. One major impediment to progress has been the failure to consider task effects when mapping speech-related processing systems. We summarize a dual stream model of speech processing that addresses this situation. In this model, a ventral stream processes speech signals for comprehension, and a dorsal stream maps acoustic speech signals to parietal and frontal lobe articulatory networks. The model assumes that the ventral stream is largely bilaterally organized, although there are important computational differences between the left and right hemisphere systems, whereas the dorsal stream is strongly left hemisphere–dominant.
TIPS-pentacene triplet exciton generation on PbS quantum dots results from indirect sensitization

Many fundamental questions remain in the elucidation of energy migration mechanisms across the interface between semiconductor nanomaterials and molecular chromophores. The present transient absorption study focuses on PbS quantum dots (QDs) of variable size and band-edge exciton energy (ranging from 1.15 to 1.54 eV) post-synthetically modified with a carboxylic acid-functionalized TIPS-pentacene derivative (TPn) serving as the molecular triplet acceptor. In all instances, selective excitation of the PbS NCs at 743 nm leads to QD size-dependent formation of an intermediate with time constants ranging from 2–13 ps, uncorrelated to the PbS QD valence band potential. However, the rate constant for the delayed formation of the TPn triplet excited state markedly increases with increasing PbS conduction band energy, featuring a parabolic Marcus free energy dependence in the normal region. These observations provide evidence of an indirect triplet sensitization process being inconsistent with a concerted Dexter-like energy transfer process. The collective data are consistent with the generation of an intermediate resulting from hole trapping of the initial PbS excited state by midgap states, followed by formation of the TPn triplet excited state whose rate constant and yield increases with decreasing quantum dot size.
Cyathitepala papillosa gen. et sp. nov., a mid-Cretaceous fossil flower from Myanmar amber with valvate anthers

Although partially damaged prior to its preservation in coniferous resin, the flower of Cyathitepala papillosa retains enough morphological features to justify its description as a new genus and species of fossil angiosperms. The perianth is incomplete, but there are at least 6 large outer tepals and numerous smaller, spirally arranged inner ones. The limbs of some of the larger tepals are cup-shaped and face abaxially, while the smaller inner tepals are flat or have adaxially folded margins. There is an inner series of erect, apically truncate tepals surrounding the stamens. The surfaces and margins of the tepals are densely papillate. There is a whorl of ca. 12 stamens with anthers that dehisce by two dorsally hinged valves. Nothing remains of the receptacle or pedicel of the flower, but the superior portion of the pistil is conic and bears two columnar, erect styles. The fossil is compared with three previously described fossil genera, Setitheca, Zygadelphus, and Strombothelya, which were suggested as having a possible relationship with certain families of order Laurales.
CIRCUMBINARY MAGNETOHYDRODYNAMIC ACCRETION INTO INSPIRALING BINARY BLACK HOLES

We have simulated the magnetohydrodynamic evolution of a circumbinary disk surrounding an equal-mass binary comprising two non-spinning black holes during the period in which the disk inflow time is comparable to the binary evolution time due to gravitational radiation. Both the changing spacetime and the binary orbital evolution are described by an innovative technique utilizing high-order post-Newtonian approximations. Prior to the beginning of the inspiral, the structure of the circumbinary disk is predicted well by extrapolation from Newtonian results: a gap of roughly two binary separation radii is cleared, and matter piles up at the outer edge of this gap as inflow is retarded by torques exerted by the binary; the accretion rate is roughly half its value at large radius. During inspiral, the inner edge of the disk initially moves inward in coordination with the shrinking binary, but—as the orbital evolution accelerates—the inward motion of the disk edge falls behind the rate of binary compression. In this stage, the binary torque falls substantially, but the accretion rate decreases by only 10%-20%. When the binary separation is tens of gravitational radii, the rest-mass efficiency of disk radiation is a few percent, suggesting that supermassive binary black holes could be very luminous at this stage of their evolution. Inner disk heating is modulated at a beat frequency comparable to the binary orbital frequency. However, a disk with sufficient surface density to be luminous may be optically thick, suppressing periodic modulation of the luminosity.
Calculating Reachable Workspace Volume for Use in Quantitative Medicine

Quantitative measures of the space an individual can reach is essential for tracking the progression of a disease and the effects of therapeutic intervention. The reachable workspace can be used to track an individuals’ ability to perform activities of daily living, such as feeding and grooming. There are few methods for quantifying upper limb performance, none of which are able to generate a reachable workspace volume from motion capture data. We introduce a method to estimate the reachable workspace volume for an individual by capturing their observed joint limits using a low cost depth camera. This method is then tested on seven individuals with varying upper limb performance. Based on these initial trials, we found that the reachable workspace volume decreased as muscular impairment increased. This shows the potential for this method to be used as a quantitative clinical assessment tool.
Evolutionary dissociations between homologous genes and homologous structures

Phenotype is encoded in the genome in an indirect manner: each morphological structure is the product of many interacting genes, and most regulatory genes have several distinct developmental roles and phenotypic consequences. The lack of a simple and consistent relationship between homologous genes and structures has important implications for understanding correlations between evolutionary changes at different levels of biological organization. Data from a variety of organisms are beginning to provide intriguing glimpses of the complex evolutionary relationship between genotype and phenotype. Much attention has been devoted to remarkably conserved relationships between homologous genes and structures. However, there is increasing evidence that several kinds of evolutionary dissociations can evolve between genotype and phenotype, some of which are quite unexpected. The existence of these dissocations limits the degree to which it is possible make inferences about the homology of structures based solely on the expression of homologous genes.
The University of Ottawa model for obtaining the needed spectrum of psychiatric services: its relevance in the world today.

This text is an abbreviated version of a presentation given at a symposium on Health Care Systems of Management, Chair, G.J. Sarwer-Foner, at the 16th meeting of the World Association of Social Psychiatry, Aug. 18, 1998, Vancouver, BC. The complete unedited version of the presentation may be found at www.cma.ca/jpn Competing interests: None declared. Correspondence to: Dr. Gerald J. Sarwer-Foner, Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, 3220 Bloomfield Shores Dr., West Bloomfield MI 48323; fax 248 855-8321.
Seismogenic Deformation Structures in Microbialites and Mudstones, Silurian Lockport Dolomite, Northwestern Ohio, U.S.A.

Syndepositional deformation structures are present at two different stratigraphic levels in the Silurian Lockport Dolomite at a quarry in Maumee, Ohio. Such structures are absent in this unit at twelve other quarries in northwestern Ohio. The structures at Maumee, present within stromatolites, thrombolites, and variably bedded mudstones, include convolute layers, homogenization of bedding and breccia clasts, clasts of stromatolites, boudinage structures, normal, reverse, and thrust faults, and discordant and concordant breccias. The distribution of deformation structures within beds suggests substantial control from substrate rheology, possibly resulting from differences in degrees of lithification and from variations in water content. The extensive variety of syndepositional deformation structures, juxtaposed evidence for nearly synchronous compression and dilation, proximity (4.5 km) of the structures to the largest fault in northwestern Ohio (the Bowling Green fault), and the restricted geographic distribution of the deformation structures suggest seismic shaking as a probable mode of genesis. Similarities between features produced by seismogenic deformation of siliciclastic sediments and deformation features in the Lockport Dolomite provide additional evidence that the latter features are seismogenic. It is postulated that two earthquakes, one with a magnitude 5, caused the formation of the syndepositional deformation structures present in the youngest facies in the Lockport Dolomite at Maumee quarry. The Bowling Green fault, 4.5 km west of Maumee, was a growth fault during formation of the Lockport Dolomite, and is considered to have been the source of earthquakes that created the syndepositonal deformation structures in this unit at Maumee quarry. Evidence from the Lockport Dolomite in northwestern Ohio suggests that seismogenic deformation structures created by two earthquakes along the Bowling Green fault with magnitudes of 5 did not form in this unit over large areas (i.e., all of northwestern Ohio). This evidence challenges the suggestion that syndepositional seismogenic deformation structures are always formed over a large area.
Estimating the speed and motion direction of targets using a model of the turtle retina

In this paper we show how the velocity of a moving target across the visual field can be estimated using model of a turtle retina. The model of the retinal cells is the same as obtained earlier by the authors. Using the model, we show that the motion direction and the speed, of a target moving along a straight line, with constant speed, can be estimated in two steps. The speed can be estimated independently of the angle of the optical flow induced by the target motion. Using the speed, the retinal (model) response can be rescaled and the angle of optical flow (hence of the motion direction of the target) can be estimated independently of the speed.
The decline and rise of political economy

Abstract Political economy and Public Choice emerged in the mid-1960s as sub-disciplines involving economists, political scientists, and legal scholars. Interestingly, political economy was present at the birth of these fields of inquiry but was displaced by new specialized disciplines. This essay offers an economic explanation of the decline and rise of political economy. The theory presented suggests that political economy experiences a rebound following periods of increased government intervention. But instead of inducing further specialization, the impulse leads to unification within and among disciplines.
Providing structure: The critical element

This chapter describes the various ways that the level and type of structure can be varied in an active learning course and discusses how to use the manipulation of course structure to meet the challenges presented by a diverse student body.
Synthesis and Reactions of Tungsten Alkylidene Complexes That Contain the 2,6-Dichlorophenylimido Ligand

Tungsten alkylidene complexes that contain the 2,6-dichlorophenylimido ligand (NArCl), W(NArCl)(CHCMe3)(ORF6)2 and W(NArCl)(CHCMe3)(Biphen)(THP) (ORF6 = OCMe(CF3)2; Biphen2- = 3,3‘-di-t-Bu-5,5‘,6,6‘-tetramethyl-1,1‘-biphenyl-2,2‘-diolate; THP = tetrahydropyran), have been prepared from W(NArCl)(CHCMe3)(OSO2CF3)2(dme). Reaction of W(NArCl)(CHCMe3)(ORF6)2 with excess ethylene gave the tungstacyclobutane complex W(NArCl)(ORF6)2(C3H6), while reaction of W(NArCl)(CHCMe3)(ORF6)2 with internal olefins gave the dimer, [W(μ-NArCl)(ORF6)2]2. W(NArCl)(CHCMe3)(Biphen)(THP) reacted with excess ethylene to give W(NArCl)(Biphen)(C3H6), which yielded W(NArCl)(Biphen)(C2H4)(THF) upon addition of THF. The tungstacyclopentane complex, W(NArCl)(Biphen)(C4H8), was formed upon treatment of W(NArCl)(Biphen)(C2H4)(THF) with ethylene. W(NArCl)(Biphen)(C3H6) decomposed to yield (inter alia) the dimeric, heterochiral methylidene complex, [W(NArCl)(Biphen)(μ-CH2)]2, which decomposed further to yield homochiral [W(NArCl)(Biphen)]2(μ-...
A novel SONOS nonvolatile flash memory device using substrate hot-hole injection for write and gate tunneling for erase

In this work, we describe a novel SONOS device suitable for future nonvolatile flash memories. Substrate hot-hole injection (HHI) through a bottom oxide is used for write and gate tunneling through a thin top oxide is employed for erase. We present device DC and dynamic characteristics at low voltages (<10 V) for SONOS devices with a gate dielectric stack consisting of a 3.8 nm bottom oxide, 1.5 nm nitride and 3.0 nm top oxide. We obtain a reduction in power consumption by 4 orders of magnitude, an improvement in retention by 90%, and an improvement in subthreshold swing by 40% with a novel write/erase technique compared with Substrate HHI for erase and channel hot electron (CHE) injection for write.
Interpreting the color effect of melanin on cocaine and benzoylecgonine assays for hair analysis: brown and black samples compared.

Abstract This paper examines the hypothesis that cocaine and BE assays of hair demonstrate a putative bias effect for darker color hair samples. Although such an effect has been reported in the literature, no one has examined this claim outside the bounds of simple significance of mean difference. In this paper a large number of black and brown hair samples are compared for cocaine and BE concentration values, and this comparison is evaluated for both significance and effect size. Two innovative measures are used to assess this relationship – a calculation of effect size using Cohen’s d, and the use of an ROC curve to evaluate the potential for a dark color bias. The paper reports mixed results for significance, but consistent results for effect size. There does not appear to be any significant effect for cocaine. While BE demonstrates a significant mean difference, both the effect size and the ROC analysis show the effect to be trivial.
Hexagonal and orthorhombic crystal structures of californium trichloride

Abstract Californium trichloride has been prepared in two crystalline modifications and single-crystal specimens of each have been studied by X-ray diffraction. The hexagonal UCl3-type crystal has unit-cell dimensions of a = 7·379(1) A and c = 4·0900(5) A and the orthorhombic PuBr3-type, a = 3·869(2) A , b = 11·748(7) A and c = 8·561(4) A . Structural parameters including anisotropic thermal motion have been refined by the method of least squares. In the hexagonal form the Cf atom is 9-coordinated by six Cl atoms at 2·815(3) A and three at 2·924(4) A, while in the orthorhombic form the coordination is 8-fold with two Cf-Cl distances of 2·690(7) A; four of 2·806(4) A and two of 2·940(6) A. An ionic radius of 0·932(3) A was derived for the 6-coordinated Cf3+ ion.
Single-Step Synthesis of Secondary Phosphine Oxides

We report that in the presence of trifluoroacetic acid primary phosphines undergo efficient addition to aldehydes to form the corresponding secondary phosphine oxides in 47−97% yield. This transformation is compatible with aryl and alkyl phosphines, as well as a broad range of aldehydes, including formaldehyde. By using 1,5-dialdehydes as reaction partners, the addition provides a straightforward route to bis(phosphine oxides), which are difficult to prepare by alternative methods. In the presence of boron trifluoride diethyl etherate as reagent, benzophenone was shown to couple to phenylphosphine and cyclohexylphosphine in 92% and 72% yield, respectively. Twenty-three examples are presented.
The market for special interest campaign funds: An exploratory approach

The results of our study support the rational behavior theory of political participation. An economic market exists for special interest campaign contributions. Campaign funds will be exchanged if money is important to election outcomes and there is a rate of return for political contributions at least equal to that from alternative forms of investment. Demand factors are important in the campaign funds market. Political candidates are found to substitute private funds for special interest campaign contributions. In general, this study appears to have provided sufficiently useful results based on theoretical expectations, to merit additional research. We consider our analysis to be exploratory. Future research should concentrate on the apparent simultaneity among the ‘productivity’ of campaign funds, the determinants of campaign funds and legislative decision-making. Econometric estimation, however, should not proceed withoui a more formal development of a theory of the collective decision making process. A final note on the implications of our study for campaign finance reform. The Campaign Finance Reform Act of 1975 sought to limit special interest contributions. The imposition of limits on campaign contributions can be considered analogous to artificial controls in other economic markets, Given the imposition of limits, it seems likely that a ‘black market’ in special interest funds will develop. This black market may take many forms: the proliferation of Political Action Committees, the ‘laundering’ of campaign funds, and extra-political payments. Because of the fluid nature of the special interest market, enforcement costs of contribution limits will be extensive. From an enforcement standpoint, additionally, the existence of a special interest black market represents a ‘crime without a victim’. Contribution limits will not reduce the influence of special interest contributors.
Environmental, genetic, and seed mass effects on winged seed production in the heteromorphic Spergularia marina (Caryophyllaceae)

Summary 1Spergularia marina (L.) Grieseb. is a cosmopolitan, autogamous herb that produces winged and unwinged seeds. In Europe, large-seeded populations tend to produce a higher proportion of winged seeds than small-seeded populations. 2This pattern has prompted speculation that winged seeds evolved because they increase the dispersability of large-seeded genotypes. Alternatively, winged seed production may be an adaptive plastic response to stress, resulting in increased dispersal. A third hypothesis is that wing production is favoured among maternal plants with high fecundity because it reduces postdispersal sibling competition. 3We present the results of a greenhouse experiment conducted to test these hypotheses using California genotypes of S. marina. Twenty-four maternal families (N = 230 plants) were replicated across three nutrient treatments. Within treatments, large-seeded fruits, individuals and families tended to produce a higher proportion of winged seeds than small-seeded ones. We found no evidence that winged seeds are induced by stress or high fecundity. 4These results are consistent with evidence that winged seed production in S. marina is positively associated with the evolution of mean seed mass, representing an adaptation that enhances the dispersability of large seeds. The low frequency of winged seeds in the population sampled here suggests that the heteromorphism may not be an important current adaptation in small-seeded populations of S. marina.
Extraction Behavior of Americium and Plutonium with Mixed Solvent Extractants

Abstract The mixed solvent extractants, dibutyl N,N-diethylcarba-moylmethylenephosphanate (DBDECMT)-tributyl phosphate (TBP), using carbon tetrachloride diluent, were studied for extracting americium (III) and plutonium (IV) from 0.35 and 7M HNO3 at 25°C. Synergistic effects were observed in this system as was the case with preliminary results (described herein) using the dihexyl analogue DHDECMP and TBP.
Reserving supraclavicular first rib resection for vascular complications of thoracic outlet syndrome

Background The traditional approach to decompression of the thoracic outlet has been by transaxillary resection of the first rib. Recently, the trend has been toward a more selective and tailored surgical approach via the supraclavicular route. Methods During a 51-month period, 14 consecutive patients underwent decompressive surgery of the thoracic outlet via the supraclavicular approach. There were ten women and four men; mean age was 44 years. Indications for operation were arterial (n=3), venous (n=2) and neurogenic (n=9). Mean follow-up was 31 months. Operation consisted of resection of the anterior scalene and medial aspect of the middle scalene muscles and brachial plexus neurolysis for neurogenic indication, with first rib resection reserved for vascular complications. Results Operations performed for vascular complication were successful and uncomplicated, with good clinical outcome. Seven of nine operations (78%) performed for neurogenic indication produced marked relief of symptoms, while two (22%) resulted in no clinical change. Complications consisted of transient scapular winging (n=1) and transient diaphragmatic paralysis (n=2). Conclusions A selective approach to thoracic outlet decompression, consisting of anterior scalenectomy and brachial plexus neurolysis for neurogenic symptoms, and reserving first rib resection for arterial and venous indications, is a safe procedure and yields satisfactory results in appropriately selected patients.
Two-dimensional optical grating produced on a poly-p-phenylene vinylene/V 2 O 5 -gel film by ultrashort pulsed laser radiation

A two-dimensional permanent transmission grating was formed on a novel polymer–gel composite film by ultrashort (∼0.5-ps) and visible (∼602-nm) pulsed laser radiation. With an arrangement of three noncoplanar coherent laser beams, we used two approaches to produce direct formation of a two-dimensional grating on the film. One approach is to expose the sample twice to different combinations of two beams, and the other is to expose the sample to three laser beams simultaneously. The diffraction patterns and the relative intensity distributions for different order diffraction of the two-dimensional gratings formed on the poly-p-phenylene vinylene/V2O5-gel films are analyzed for the different two-beam combinations and relative orientations among the three laser beams. The total diffraction efficiency for the incident probe laser beam into all the non-zero-order diffraction beams reaches 48%.
Comparative nephrotoxicity of hydroxygentamicin and other aminoglycosides in rats.

Abstract The nephrotoxicity of hydroxygentamicin and amikacin was examined in young adult Fischer 344 rats. Serum creatinine (SCr) and urea nitrogen (BUN) levels were not significantly affected following sc injection of 80 or 160 mg/kg/day of hydroxygentamicin for 15 days. However, 250 mg/kg of amikacin produced significant increases in both parameters and in kidney/body weight ratios. The ratios were also significantly increased after 80 or 160 mg/kg of hydroxygentamicin, but kidneys of rats receiving amikacin were considerably heavier than those of rats treated with hydroxygentamicin. The antibacterial potency of 250 mg/kg of amikacin is comparable to that of 100mg/kg of hydroxygentamicin. Additional studies, directly comparing hydroxygentamicin, a mutational biosynthetic, with gentamicin or netilmicin, all at 40, 80, and 160 mg base/kg, and incorporating renal function parameters as well as SCr, BUN, organ weight, tissue concentration, and kidney histopathology, revealed a characteristic pattern typical of aminoglycoside nephrotoxicity in mature adult male rats. In most parameters, values in rats given hydroxygentamicin or netilmicin were normal and comparable to those in controls, but kidney/body weight ratios were significantly increased at high doses. However, kidneys of rats medicated with gentamicin at comparable doses were considerably heavier than those of hydroxygentamicin-treated rats. Significant nephrotoxicity also was seen in rats given low doses of gentamicin or netilmicin. Eosinophilic granulation and vacuolization of renal proximal tubular epithelium, interstitial inflammation, and tubular dilation were observed microscopically with all three drugs in the following descending order of severity: gentamicin > netilmicin > hydroxygentamicin. The effects on proximal tubular epithelial cells following treatment with amikacin, netilmicin, or hydroxygentamicin correlated reasonably well with renal drug concentrations, but drug concentrations of gentamicin, which produced the most extensive kidney injury, were lower than those of the other three aminoglycosides. Elevated SCr or BUN were indicative of the presence of nephrosis, but early stages of tubular epithelial degeneration were not predicted by increases in BUN or SCr. Although minimal or mild nephrosis was seldom predicted by polyuria, proteinuria, or changes in osmolality, effects observed in renal function parameters usually correlated well with renal histopathology. However, a decrease in osmolality correlated best with enlarged kidneys and changes in renal morphology.
Relative Rates of Reaction of Bromine Atoms with Isotopic Hydrogen Molecules

Kinetic isotope effects in the reaction of bromine atoms with isotopic hydrogen molecules were measured in this investigation. Rate constant ratios were determined by isotopic analysis of H2–HD, H2–HT, or H2—D2 mixtures before and after reaction with bromine atoms. Over the temperature range of 438° to 623°K, the ratios of the second‐order rate constants were kH2/ΣkHD = (1.14±0.01) exp(591±4/RT), kH2/ΣkHT = (1.22±0.02) exp(658±16/RT), kH2/kD2 = (1.32±0.04) exp(1253±37/RT).A comparison of these results with the corresponding isotope effects obtained in the chlorine‐ and iodine‐atom experiments reveals surprisingly little difference in kinetic isotope effects.The theoretical calculation of the kinetic isotope effects was carried out using Bigeleisen's theory of isotope effects on reaction rates. The calculations were made using various methods of constructing the potential energy surface and it was found that none of the semiempirical methods used gave agreement to better than 40% to 80%.
Equivalence and Order Relations as Interrelated by Four- and Five-Year-Old Children.

When writing about Piaget's conservation problems, Elkind (1967) has stated that "every conservation problem assesses two different forms of conservation [p. 15]." The two forms he refers to are conservation of identity and conservation of equivalence. As a characterization of the conservation problems, Elkind (1967) stated: they routinely involve presenting the subject with a variable (V) and a standard (S) stimulus that are initially equivalent in both the perceptual and the quantitative sense. The subject is then asked to make a judgement regarding their quantitative equivalence. Once the judgement is made, the variable stimulus is subjected to a transformation, V -> V', which alters the perceptual but not the quantitative equivalence between variable and standard. After completion of the transformation, the subject is asked to judge the quantitative equivalence between the standard and the transformed variable [p. 16].
Retrosternal displacement after physeal fracture of the medial clavicle in children: Treatment by open reduction and internal fixation

Retrosternal displacement of the medial aspect of the clavicle after physeal fracture is rare. We treated six patients with this injury between 1995 and 1998, all as an emergency in order to avoid complications associated with compression of adjacent mediastinal structures. Attempted closed reduction was undertaken, but all required open reduction and internal fixation using a wire suture. There were no associated complications. Five were reviewed clinically and radiologically at a minimum of one year after operation. All had regained full use of the affected arm without pain and had resumed their preinjury level of activity including sports. Follow-up radiographs showed union in the anatomical position in all patients. We recommend attempted closed reduction in the operating room, followed, if necessary, by open reduction. Internal fixation after open reduction gives stable fixation with minimal morbidity.
2D multiple beam steering with acoustically steered and rotated (ASTRO) true-time delay generator

ABSTRACT2D multiple beam steering in the Acoustically STeered and ROtated (ASTRO) true time delay generationarchitecture is described. The architecture is capable of generating 2D multiple beams without causing any extraneous beams. The system can be used as both transmitter and receiver modes simultaneously.Keywords: Optical interconnection, phased array antennas, true time delays, beam steering, Fiber Bragg gratings,acousto-optic beam deflectors, optical information processing, optoelectronics, wavelength division multiplexing 1. INTRODUCTION Multiple beam steering is one of the most important features of a phased array antenna [1-10]. There have beenseveral architectures to implement 1D multiple beam generation in true-time delay systems [5]. However, asshown in Figure 1, the 2D multiple beam steering in a cascaded architecture [4-7] (whether Cartesian or polar axes) Phased y Array y Y2 ) i . (r1,01) E xl x2 (b) Figure 1 . 2D multiple beam generation in a cascaded true time delay generation architecture. The circle 0 representsthe desired beam directions and the X mark represents undesired ones.
An abundance exchange model of fish assemblage response to changing habitat along embayment–stream gradients of Lake Ontario, New York

Abstract A spatially explicit abundance exchange model (AEM) was developed to predict distribution patterns of five fish species in relation to their population characteristics and habitat preferences along two embayment–stream gradients associated with Lake Ontario, New York. The five fish species were yellow perch ( Perca flavescens ), bluegill ( Lepomis macrochirus ), logperch ( Percina caprodes ), bluntnose minnow ( Pimephales notatus ), and fantail darter ( Etheostoma flabellare ). Preference indexes of each target fish species for water depth, water temperature, current velocity, cover types (aquatic plants, algae, and woody debris), and bottom substrates (mud, sand, gravel-cobble, and rock-bedrock) were estimated from the field observations, and these were used to compute habitat preference (HP) of the associated fish species. Fish HP was a key variable in the AEM to quantify abundance exchange of an associated fish species among habitats on each study gradient. According to the results, the AEM efficiently determined local distribution ranges of the fish species on one study gradient. Results from the model validation showed that the AEM with its estimated parameters was able to quantify most of the fish species distributions on the second gradient. Overall, the AEM is rigorous for quantifying the distribution patterns of the target species along the changing habitat gradients. With its flexible structure that is applicable for array functions and differential equations from both static and dynamic components, the AEM can be modified to determine patterns of organism distribution in complex systems with different environments and geography.
The tip link's role in asymmetric stereocilia motion of chick cochlear hair cells

The symmetry of chick cochlear hair bundle motion was examined in this study. Isolated segments from the basilar papilla were incubated in vitro in either normal or low calcium medium, which is known to disrupt tip links. Stereociliary bundles, stimulated with an oscillating water microjet, were oriented in profile and viewed in slow motion at high magnification with stroboscopic illumination. The displacement of the tallest hair in the bundle was fixed to 20 degrees peak-to-peak (P-P) motion. The angular deflections of the shortest and tallest hairs were then measured in both the positive (towards the tallest hair) and negative (towards the shortest) directions with respect to the non-stimulated position of the hair. The tallest hairs exhibited nearly symmetric motion in medium containing normal and low calcium. The shortest hairs, in normal calcium, displayed considerable asymmetry with angular deflections in the positive direction significantly larger than in the negative direction. This asymmetric motion disappeared after incubation in low calcium. The shortest hair angular displacement in the negative direction, however, was the same in both normal and low calcium conditions. These results indicated that the tallest and shortest hairs moved with equal angular deflection in the negative direction, while in the positive direction the shortest hair moved through a significantly greater angular deflection than the tallest hair. The implication of this finding is that the tip links contributed significantly to hair bundle motion in the positive direction only.