cssi/SciSciGPT-SciSciNet huggingface dataset:
Supportless PdFe nanorods as highly active electrocatalyst for proton exchange membrane fuel cell

Abstract The PdFe nanorods (PdFe-NRs) with tunable length were synthesized by an organic phase reaction of [Pd(acac)2] and thermal decomposition of [Fe(CO)5] in a mixture of oleyamine and octadecene at 160 °C. They show a better proton exchange membrane fuel cell (PEMFC) performance than commercial Pt/C in working voltage region of 0.80–0.65 V, due to their high intrinsic activity to oxygen reduction reaction (ORR), reduced cell inner resistance, and improved mass transport.
The effect of aluminum additions on the structural and hydrogen absorption properties of AB5 alloys with particular reference to the LaNi5−xAlx ternary alloy system

Abstract The dissociation pressures of the hydrides LaNi4.6Al0.4H6, LaNi4.5Al0.5H6, CFMNi4.8Al0.2H6 (CFM = cerium-free mischmetal), CFMNi4.6Al0.4H6 and YNi4AlH4 were studied. In all cases, the aluminum additions were found greatly to reduce the plateau pressure of the ANi5−x Alx hydride compared with that of the corresponding ANi5 hydride (A = La, CFM, Y). LaNi4.6Al0.4 and LaNi4.5Al0.5 were specially prepared homogeneous alloys whose enthalpies and entropies of transition were calculated as − 8.7 kcal (mol H2)−1, − 9.2 kcal (mol H2)−1 − 26.1 cal (mol H2)−1 deg−1 and 26.6 cal (mol H2)−1 deg−1, respectively. A crystallographic model of LaNi4Al is shown and consideration of the nearest neighbor atom distribution leads to a rationalization of the observed linear relationship between the enthalpy change ΔH and the Al composition. A recently proposed model of hydrogen interstitial site occupation is examined in the light of the present data. Finally, correlations of hydride dissociation pressures with either alloy heats of formation or alloy cell volumes are discussed.
Ecosystem model of an estuarine submersed plant community: Calibration and simulation of eutrophication responses

As water quality in the Chesapeake Bay has declined over recent decades, formely healthy submersed plant communities have disappeared from littoral areas of the mesohaline estuary. A dynamic simulation model of shallow regions of bay tributaries (<1 m) was developed to investigate growth responses of submersed vascular plants to eutrophication and habitat degradation. Our objectives were to elucidate mechanisms responsible for the decline and to evaluate conditions required for plant restoration and survival. State varibles in the model are plant leaves, roots, phytoplankton, epiphytes, and detrital material. The model calculates biomass pools and biogeochemical rate processes over annual cycles with a time step of 6 h. Simulations were performed to investigate the influence of phytoplankton and epiphytes on the underwater light environment, how the balance of limiting resources (light and nutrients) controls growth and productivity of submersed plants, and conditions necessary, for the restoration of submersed vegetation. Model output for submersed plants was calibrated to baseline data from the mid 1970s (r2=0.86); simulations reproduced declines in plant biomass with increasing nutrient enrichment. Model experiments showed, that by increasing nutrient inputs 40% above levels observed in the 1960s, submersed plants disappeared within 1–2 yr due to enhanced growth of phytoplankton and epiphytes, which reduced light below required levels. Epiphytes were more important than were phytoplankton in attenuating light. The relationship between nutrient enrichment and plant loss rate was complex, as epiphyte density on leaf surfaces was not linearly related to nutrient levels. Relatively small nutrient increases could have a large effect on submersed plants because epiphyte density on leaves increased exponentially as leaf surface area decreased. Exchanges of organic carbon and nutrients between leaf and root compartments were seasonally variable and were critical for survival of submersed plants. The amount of root-rhizome material available for regrowth could control the outcome of nutrient reduction strategies. Consequently, model predictions of plant restoration success were highly dependent on initial conditions. The model is being used successfully as a research tool to interpret ecological relationships in the ongoing re-evaluation of management alternatives for submersed plant restoration.
Hippocampal interneuron transplants reverse aberrant dopamine system function and behavior in a rodent model of schizophrenia

Schizophrenia patients exhibit increased hippocampal activity that is correlated with positive symptoms. Although the cause of this hippocampal hyperactivity has not been demonstrated, it likely involves a decrease in GABAergic signaling. Thus, we posit that restoring GABAergic function may provide a novel therapeutic approach for the treatment of schizophrenia. It has been demonstrated that transplanted GABAergic precursor cells from the medial ganglionic eminence (MGE) can migrate and differentiate into mature interneurons. Here, we demonstrate that ventral hippocampal MGE transplants can restore hippocampal function and normalize downstream dopamine neuron activity in a rodent model of schizophrenia. Furthermore, MGE transplants also reverse the hyper-responsive locomotor response to amphetamine. Taken together, these data demonstrate that restoring interneuron function reverses neurophysiological and behavioral deficits in a rodent model of schizophrenia and moreover, demonstrate the feasibility of a neuronal transplant procedure as a potential novel therapeutic approach for the treatment of schizophrenia.
Kummerform Foraminifera as Clues to Oceanic Environments: ABSTRACT

Most planktonic foraminiferal shells resemble strings of hollow spheres of increasing diameter. The strings are coiled in a plane or on the surface of a cone. Shells of this type are defined as "normalform." Of all the chambers making up such a string, generally the last one only may be smaller than or equal to the previous one. If a foraminifer builds such a chamber, it leaves the normalform stage and enters the "kummerform" stage (German kummerlich = measly). Attainment of the kummerform stage probably indicates environmental stress, notably lack of food. In many samples of calcareous deep-sea sediment, a large proportion of the planktonic Foraminifera are kummerforms. This contrasts with the living populations in the upper water column where kummerforms are rare. The enrichment of deep-sea sediment with kummerform Foraminifera may be caused by (1) a greater propensity for living kummerforms, than for normalforms, to deliver an empty shell and (2) selective destruction of normalforms on the ocean floor. There is evidence that both mechanisms may be important, depending on the oceanic environment in the upper water and on the ocean floor. Vigorous oceanic circulation may increase the proportion of kummerforms. Changes in the stability of oceanic environments thus may be recorded in the amount of kummerform Foraminifera in older deep-sea deposits. End_of_Article - Last_Page 706------------
Relative contributions of MCM1 and STE12 to transcriptional activation of a- and alpha-specific genes from Saccharomyces cerevisiae.

We have examined the relative contributions of MCM1 and STE12 to the transcription of the a-specific STE2 gene by using a 367 by fragment from the STE2 5′-noncoding region to drive expression of a reporter lacZ gene. Mutation of the MCM1 binding site destroyed MCM1 · α2-mediated repression in α cells and dramatically reduced expression in a cells. The residual expression was highly stimulated by exposure of cells to pheromone. Likewise, the loss of STE12 function reduced lacZ expression driven by the wild-type STE2 fragment. In the absence of both MCM1 and STE12 functions, no residual expression was observed. Thus, the STE2 fragment appears to contain two distinct upstream activation sequences (UASs), one that is responsible for the majority of expression in cells not stimulated by pheromone, and one that is responsible for increased expression upon pheromone stimulation. In further support of this idea, a chemically synthesized version of the STE2MCM1 binding site had UAS activity, but the activity was neither stimulated by pheromone nor reduced in ste12 mutants. Although transcription of aspecific genes also requires both MCM1 and STE12, these genes differ from a-specific genes in that they have a single, MCM1-dependent UAS system. The activity of the minimal 26 by UAS from the α-specific STE3 gene was both stimulated by pheromone and reduced in ste12 mutants. These data suggest that at α-specific genes STE12 and MCM1 exert their effects through a single UAS.
A Critical Review of Oil Spill Risk Analysis

The literature on oil spill risk analysis is reviewed. Various results on the locational distribution of oil spills, spill frequencies and spill volumes are provided. A comprehensive methodological framework is developed for analyzing oil spill risk to a given geographical region.
Understanding Mathematics Achievement: An Analysis of the Effects of Student and Family Factors.

Educators are increasingly recognising the importance of improving students’ mathematics achievement. Much of the current research focuses on the impact of instructional variables on mathematics achievement. The goal of this study was to examine the influence of less researched variables – family and student factors. Participants were 747 economically disadvantaged elementary students grades K-8 in Ohio. Predictor variables included: (a) 13 factors from a parent survey on both child and family circumstances and (b) reading achievement, measured by a norm-referenced achievement test. Outcome variables included three mathematics scales from the same achievement test. Regression analyses examined the impact of the predictors on the outcomes. Reading achievement significantly predicted mathematics achievement for all three outcomes. Parent pessimism and parent-perceived school/cognitive competence of children also emerged as significant predictors for two of the three mathematics outcomes. Implications for re...
Moral duties of parents and nontherapeutic clinical research procedures involving children.

Shared views regarding the moral respect which is owed to children in family life are used as a guide in determining the moral permissibility of nontherapeutic clinical research procedures involving children. The comparison suggests that it is not appropriate to seek assent from the preadolescent child. The analogy with interventions used in family life is similarly employed to specify the permissible limit of risk to which children may be exposed in nontherapeutic research procedures. The analysis indicates that recent writers misconceive how certain moral principles, such as respect for personal autonomy, require us to act toward children. The results are also used to assess proposed federal regulations on research with children.
Plankton assemblages in the ice edge zone of the Weddell Sea during the austral winter

Abstract Plankton studies in Antarctic waters have emphasized the importance of diatoms. The species composition, abundances and contribution to biomass of the other planktonic groups are stil poorly documented. This is particularly true for the heterotrophic members of the nano- and microplankton assemblage. As part of the Antarctic Marine Ecosystem Research in the Ice age Zone (AMERIEZ) program, we sampled nano- and microplankton across the ice edge zone during the austral winter. A variety of microscopial techniques allowed us to the composition, trophic mode and biomass of the spectrum of organisms that make up the winter plankton assemblage. Total nano- and microplankton biomass in the upper 100 meters of the water column ranged from 0.3 to 0.6 gC m −2 . The biomass composition of plankton assemblages among the stations was relatively uniform throughout the ice edge zone; however, the autotrophic flagellates and dinoflagellates showed significantly higher biomass at the ice edge or in open water relative to ice covered stations. The heterotrophic biomass (protozooplankton) exceeded the biomass of phytoplankton at most stations. Among the autotrophic forms, dinoflagellates made up 38% of the biomass, followed by other autotrophic flagellates (35%) and diatoms (27%). The phytoplankton biomass was dominated by nanoplankton ( μ m). Dinoflagellates also dominated among the heterotrophs, making up as much as 73% of the total heterotrophic biomass. Most of the heterotrophic dinoflagellates were μ m. The ciliates present were mostly non-sheathed oligotrichs. Tintinnids were present but in densities of usually −1 . Many of the larger oligotrichous ciliates examined contained sequestered chloroplasts, which have been reported to retain photosynthetic activity. Larger protozoans (e.g., Radiolaria, Acantharia and Foraminifera) were a minor constituent of the plankton biomass in surface waters. This study suggests that winter plankton assemblages were dominated by nanoplankton for both algae and protozoans. The abundance of athecate dinoflagellates, both autotrophic and heterotrophic forms, was unusual and warrants further investigation of the role of these organisms in the Antarctic plankton community. Generally low production and the high abundance of heterotrophic organisms relative to the phytoplankton, suggests the protozooplankton will be important in utilizing winter primary and bacterial production and transferring this production to higher levels of the food web.
Experience with flexibility in an academic residency program

greater flexibility also might be beneficial if individuals are to be prepared for productive, academic research careers. Many of the current obstetric-gynecologic leaders in reproductive research pursued training programs that would be proscribed by current guidelines of the subspecialty boards. Thus, while many spent 1 or 2 years in a laboratory either abroad or in a basic science department in the United States, these are not components of “approved” programs of the current subspecialty disciplines. Furthermore, extensive clinical requirements, for example, the need for reproductive endocrinologists to train in tubal microsurgery and in vitro fertilization, and the large amounts of time in clinical pursuits mandated in fetal and maternal medicine and oncology mitigate against obtaining the requisite training to pursue an independent, productive, and competitive research-oriented career-and the discipline sorely needs this facet of the specialty better represented. Although I was not personally involved, the activity of this Society of which I have been most supportive and proud has been the creation of the Kennedy-Dannreuther fellowships. They furnish tangible evidence of the Society’s commitment to training investigators in the reproductive sciences. To maximize these opportunities, the greatest possible program flexibility needs to be encouraged and facilitated.
Large-Scale Testing of a Replaceable “Fuse” Steel Coupling Beam

When coupled core wall (CCW) systems are built in regions of high seismicity, the ductility demands on the coupling beams can be of critical concern. Steel coupling beams, whether encased in concrete or not, offer a very high degree of ductility relative to common concrete coupling beams. Hybrid core wall systems, that is CCW systems with steel or steel/concrete composite coupling beams, provide excellent lateral stiffness from the walls and coupling action, while providing excellent energy dissipation and ductility characteristics of steel coupling beams. Previous research pertaining to steel coupling beams has made great strides in furthering the understanding of the behavior of steel coupling beams, and recommendations regarding design methodologies have been established. However, as steel coupling beam ends are embedded in the wall piers, postdamage repair can be costly. This paper presents the results of large-scale cyclic tests of a steel coupling beam designed and detailed based on the writers’ pre...
Enzyme-linked immunosorbent assay for the activator protein specific for the enzymic hydrolysis of GM1 in urine

We have established a sensitive and specific enzyme-linked immunosorbent assay (ELISA) for the detection of the activator protein which stimulates the enzymic hydrolysis of GM1 (GM1-activator) in human urine. The level of GM1-activator in 19 normal, adult urine samples was estimated to be 370.7±33.2 ng/ml. The amounts of GM1-activator excreted in 24 h were estimated to be between 0.28 and 1.1 mg. The coefficient of variation for this method is 4.3% for the intra-assay and 14.4% for the inter-assay. Urine samples, without purification, can be used directly for the ELISA.
Trust in Planning: Theoretical and Practical Considerations for Participatory and Deliberative Planning

Trust is a central element of planning practice because the profession is positioned at the nexus of public and private interests, has a crucial role in the contested management of space, and seeks to promote democratic governance and public participation in local decision making. While trust (social and interpersonal) is often cited as a central factor contributing to the success or failure of participatory planning processes and of plan implementation, its role in planning has not been fully conceptualized. Building on the literature on trust in governance, this paper highlights key characteristics and paradoxes of trust, discusses the importance of trust for cooperation and planning, and presents the factors that hinder and promote trust. This discussion provides the bases for planning practice and research aimed at effective trust building.
Performance evaluation of a particle-enhanced turbidimetric cystatin C assay on the Hitachi 917 analyzer.

Abstract Background Human cystatin C is a low molecular weight protein that has been proposed as a new endogenous marker of glomerular filtration rate. We investigated the performance of the Genzyme cystatin C assay on the Hitachi 917 analyzer. Methods Imprecision, linearity, recovery, and interference studies were performed on the Hitachi 917 analyzer. For method comparison, split sample aliquots were assayed using the described method and 2 other commercially available cystatin C assays. Results The assay was linear from 0.24 to 6.36 mg/l. Within-run coefficient of variation (CV) was 4.2 and 0.8% at cystatin C concentrations of 0.50 and 2.00 mg/l, respectively. Between-run CV was 4.3 and 2.7% at the same concentrations. The average analytical recovery was 99%. Bilirubin (≤ 30 mg/dl), triglycerides (≤ 1000 mg/dl), intralipid (L index ≤ 1000), and rheumatoid factor (≤ 1000 IU/ml) did not interfere with the assay. A > 10% change in cystatin C level was observed when hemoglobin concentration was > 800 mg/dl. The assay compared well with the Dade Behring immunonephelometric assay and the Dako immunoturbidimetric assay. Conclusion The Genzyme cystatin C immunoassay is an acceptable method for the determination of cystatin C on the Hitachi 917 analyzer.
Complications of percutaneous transfemoral coronary arteriography.

Complications statistics in 1625 patients undergoing selective coronary angiography by Judkin's technique have been analysed for four major areas — death, myocardial infarction, cerebral vascular accidents, and femoral thrombosis. Over a six-year period, considerable decrease in the number of complications has occurred. Myocardial infarctions have decreased from 2·4% (1967–71) to 0·44% (1973), an improvement related to careful catheter flushing, guidewire insertion technique and careful pressure monitoring within the coronary arteries. Cerebral accidents have decreased from a maximum of 1·3% (1972) to none (1973). This is also related to catheter guidewire techniques, and to avoidance of entering the cerebral vessels inadvertently when crossing the aortic arch with the coronary catheter. Femoral artery thromboses have decreased from 2·7% (1967–71) to none (1973). This is due to monitoring the dorsalis pedis pulse when compressing the femoral artery and avoiding complete femoral arterial obstruction with the associated lack of flow ultimately leading to thrombosis. Death rate has remained essentially unchanged (0·3–0·6%).
Microanalysis of catechols as lead salts by infrared spectroscopy.

Abstract A method is described for qualitative determination of various catechols in the microgram range based on the infrared spectra of their lead salts. Neutral Pb(OAc) 2 precipitated catechols as their lead salts from aqueous and from ether solutions. From 5 ml aqueous solution, 25 μg catechol was easily recovered and identified by IR as lead catecholate. The salts could be reconverted to free catechols by treatment with (NH 4 ) 2 S, H 2 S, or H 2 SO 4 and this solution analyzed directly by gas chromatography. Two muconic acids were also precipitated by Pb(OAc) 2 and characterized by their IR spectra.
Adaptive motion vector resolution with implicit signaling

In all video coding standards, motion vectors are restricted to have the same resolution for the whole sequence. In this paper, we propose an adaptive motion vector resolution scheme to improve the coding efficiency. The scheme is based on an analytical model of motion compensated residue which studies the relationship between motion vector errors and the variance of the residue. With this model, the proposed scheme can adaptively select motion vector resolution with implicit signaling. Experimental results show that the proposed scheme can improve coding efficiency at slightly increased encoding complexity.
miR-8 controls synapse structure by repression of the actin regulator enabled.

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression that play important roles in nervous system development and physiology. However, our understanding of the strategies by which miRNAs control synapse development is limited. We find that the highly conserved miRNA miR-8 regulates the morphology of presynaptic arbors at the Drosophila neuromuscular junction (NMJ) through a postsynaptic mechanism. Developmental analysis shows that miR-8 is required for presynaptic expansion that occurs in response to larval growth of the postsynaptic muscle targets. With an in vivo sensor, we confirm our hypothesis that the founding member of the conserved Ena/VASP (Enabled/Vasodilator Activated Protein) family is regulated by miR-8 through a conserved site in the Ena 3′ untranslated region (UTR). Synaptic marker analysis and localization studies suggest that Ena functions within the subsynaptic reticulum (SSR) surrounding presynaptic terminals. Transgenic lines that express forms of a conserved mammalian Ena ortholog further suggest that this localization and function of postsynaptic Ena/VASP family protein is dependent on conserved C-terminal domains known to mediate actin binding and assembly while antagonizing actin-capping proteins. Ultrastructural analysis demonstrates that miR-8 is required for SSR morphogenesis. As predicted by our model, we find that Ena is both sufficient and necessary to account for miR-8-mediated regulation of SSR architecture, consistent with its localization in this compartment. Finally, electrophysiological analysis shows that miR-8 is important for spontaneous neurotransmitter release frequency and quantal content. However, unlike the structural phenotypes, increased expression of Ena fails to mimic the functional defects observed in miR-8-null animals. Together, these findings suggest that miR-8 limits the expansion of presynaptic terminals during larval synapse development through regulation of postsynaptic actin assembly that is independent of changes in synapse physiology.
Intravenous immunoglobulin in the treatment of Stevens–Johnson syndrome and toxic epidermal necrolysis: a meta-analysis with meta-regression of observational studies

Background Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe disorders with significant morbidity and mortality. The therapeutic use of intravenous immunoglobulin (IVIG) is based on limited data. Objectives This systematic review evaluates the existing literature to determine if IVIG impacts the standardized mortality rate (SMR) in patients with SJS or TEN. Methods The MEDLINE database was searched for the period 1966–2011 for pertinent studies. The bibliographies of selected references were also reviewed for additional studies. Inclusion criteria required the studies to refer to patients who received IVIG for SJS or TEN, the severity of which was determined using the SCORTEN system. Thirteen studies were used in the final analysis. Demographic data, IVIG dosing, SCORTEN score, and mortality rates were extracted. Results Of the 13 studies, eight included a control group. Meta-analysis revealed that differences in SMRs were not significant (−0.322, 95% confidence interval [CI] −0.766 to 0.122; P = 0.155). The overall SMR point estimate for all 13 studies was 0.814 (95% CI 0.617–1.076). Meta-regression demonstrated a strong inverse correlation between IVIG dosage and SMRs (slope: −0.59, 95% CI −0.14 to −1.03; P = 0.009). Conclusions Intravenous IG at dosages of ≥2 g/kg appears to significantly decrease mortality in patients with SJS or TEN.
Vibrational analysis and ionization potentials of XCH3 (X=Be,Mg,Ca) calculated by hybrid density functional theory and high order ab initio methods

Abstract The amount of attention dedicated to the theoretical and experimental investigation of small cationic organometallic systems in the literature is very limited. In this Letter we use the B3LYP method with a variety of basis sets as well as the very advanced CBS-Q, CBS-QB3, G1, G2MP2, G2, G3, and G3B3 ab initio methods in order to analyze the vibrational spectra as well as ionization potentials of BeCH3,MgCH3 and CaCH3. The need for further addition of experimental data to the archives for these systems is discussed, as well as recommendations for which theoretical methods are optimum for a particular result.
Site-specific mutagenesis using a gapped duplex vector: A study of translesion synthesis past 8-oxodeoxyguanosine in E. coli

We have constructed a gapped plasmid vector in which a single defined lesion is introduced, site-specifically, within a single-strand region. Efficiency of translesional synthesis is determined by the number of colonies recovered following transformation of E. coli. The nucleotide sequence of progeny plasmids in the gapped region of the vector reflects incorporation of bases opposite and near the lesion. The analysis detects non-mutagenic as well as mutagenic events. This system was used to establish the mutagenic potential of 2'-deoxy-7,8-dihydro-8-oxoguanosine (8-oxodG), a lesion produced by the action of active oxygen species on DNA. The presence of 8-oxodG did not affect the number of transformants recovered. Most transformants (greater than 99%) contained G:C pairs at the site of the lesion; however, a limited number of targeted G----T transversions were observed in the presence and absence of SOS induction. Base substitutions neighboring the lesion, reported for an in vitro system, were not observed. We conclude that the 8-oxodG lesion in DNA is weakly mutagenic in E. coli.
Improving coverage for children under health reform will require maintaining current eligibility standards for Medicaid and CHIP.

When the Affordable Care Act of 2010 is fully implemented, it will extend health insurance coverage to many adult Americans who currently lack it. It is not known, however, how the health reform legislation will affect children and parents who would otherwise be uninsured. Based on our analysis, the Affordable Care Act has the potential to cut the number of uninsured children by about 40 percent, from 7.4 million to 4.2 million, and the number of uninsured parents by almost 50 percent, from 12.7 million to 6.6 million. However, the actual impact will depend on increasing the share of children and parents who are enrolled in public coverage and on other implementation outcomes. Most strikingly, if the requirement that states continue their Medicaid and Children’s Health Insurance Program (CHIP) coverage is rescinded and if Congress does not continue funding CHIP, the uninsurance rate of children could more than double, increasing from 4.2 million to 7.9–9.1 million children. In that case, the uninsurance r...
Reinventing Family Therapy: Teaching Family Intervention as a New Treatment Modality

Objective This article discusses the pedagogy of teaching family therapy in the new millennium. It draws on the strengths of “family systems therapy” but goes beyond it—suggesting a new paradigm, new terminology, and a new teaching perspective. It discusses the historical background of family therapy training, a scientific foundation for what residents should be taught, and an integrative clinical model for how it could be taught.
Phytoplankton patchiness and frontal regions

In the Chesapeake Bay estuary there are persistent seasonal frontal and interfrontal regions that serve to deliver and retain different phytoplankton populations. The “patchiness” of phytoplankton, both in total chlorophyll a concentrations and in species compositions and abundances, is shown to be causally related to density flow forcing which results in these frontal and interfrontal regions. The delineation of these regions by on-line, two-dimensional profiling of density isopleths serves to identify stations within these regions for biological and chemical sampling as opposed to sampling on an arbitrary geographical grid. It is possible, by superposition of nutrient and organism concentration isopleths upon salinity isopleths, to infer conservative and non-conservative features of the system.
Boolean rings and reciprocal eigenvalue properties

Abstract Let A be the adjacency matrix of the zero-divisor graph Γ ( R ) of a finite commutative ring R containing nonzero zero-divisors. In this paper, it is shown that Γ ( R ) is the zero-divisor graph of a Boolean ring if and only if det ( A ) = - 1 . Also, A is similar to plus or minus its inverse whenever R is a Boolean ring. As a consequence, it is proved that Γ ( R ) is the zero-divisor graph of a Boolean ring if and only if the set of eigenvalues (including multiplicities) of Γ ( R ) can be partitioned into 2-element subsets of the form { λ , ± 1 / λ } . Furthermore, any finite Boolean ring R is characterized by the degree and coefficients of the characteristic polynomial of A.
Acoustic cavitation nuclei survive the apparent ultrasonic destruction of albunex® microspheres

Abstract The hypothesis tested was that gas bodies capable of nucleating violent cavitation activity in vitro would survive the rapid disruption of Albunex ® microspheres by 1-MHz ultrasound. Human erythrocyte hemolysis was used as a proxy measure of cavitation. Fluid (5% human serum albumin [HSA]) with or without Albunex ® (ALX) was exposed or sham-exposed to 1-MHz ultrasound (P + = 1.25 ± 0.01 MPa, P − = 0.81 ± 0.01 MPa; I SPTP ∼ 35 W/cm 2 ) for 60 s using 10-μs pulses and a duty factor of 0.5. An equal volume of whole human blood was then added to the fluid, followed by a second 60-s treatment. Insonation of cell suspensions prepared in previously sham-exposed HSA + ALX fluid produced about 4% hemolysis, a level significantly greater than in the controls. Insonation of cell suspensions prepared in previously insonated HSA + ALX fluid produced about 0.4% hemolysis; this also differed significantly from the controls. The data thus support the hypothesis.
Corticosteroid actions from neuronal membrane to behavior: Neurophysiological mechanisms underlying rapid behavioral effects of corticosterone

Investigation of the rapid suppression of male courtship clasping behavior by corticosterone in roughskin newts (Taricha granulosa) has led to the identification of a specific neuronal membrane receptor for this stress steroid. This paper describes studies of the neurophysiological effects of the rapid, membrane receptor mediated action of corticosterone on neurons that are involved in the control of clasping. In freely behaving newts, medullary neurons, including reticulospinal neurons, process clasp-triggering sensory signals and participate in control of clasping movements. Corticosterone injection causes these brainstem neurons to show selective depression of clasping-related sensorimotor function. These corticosterone effects appear in 3-10 min and are closely associated with the simultaneous depression of clasping. In addition to these functionally specific effects, corticosterone simultaneously causes widespread, primarily depressive effects on neuronal activity and excitability in the medulla and elsewhere in the brain. Thus, the membrane actions of corticosterone lead to diverse neural effects, including changes in membrane excitability as well as specific, network-level actions that are apparent only during behavior. These rapid corticosterone effects strongly interact with actions of the neuropeptides vasotocin and corticotropin-releasing factor, such that the form and magnitude of the steroid's effects depend on the prevailing neuroendocrine state of the brain.
Modeling Sustainability in Product Development and Commercialization

In this article, the authors present the framework of a model that integrates strategic product development decisions with the product's impact on future conditions of resources and the environment. The impact of a product on stocks of nonrenewable sources and sinks is linked in a feedback loop to the cost of manufacturing and using the product and to the end-users' preference for a sustainable product. Two product development scenarios are analyzed to illustrate the model's capabilities. These cases represent widely different market conditions and strategies in product development vis-a-vis sustainable product design and manufacturing. Future work must focus on application of the present framework to cases of realistic products and markets to further develop the model as a useful decision-making tool. The model might also serve as a means of analyzing normative resource-cost scenarios in regulatory policy mechanisms for sustainability.
Can there be a convergent perturbation theory of intermolecular energies

We investigate the relationship between the convergence of Rayleigh-Schrodinger perturbation theory and the degree of correspondence between the eigenvalues and eigenfunctions of a Hamiltonian Ȟ and those of a zero-order Hamiltonian Ȟ0. We show that the radius of convergence of the perturbation expansion that transforms Ψ01, the lowest energy eigenfunction of Ȟ0, into Ψj, the jth lowest eigenfunction of Ȟ, is less than the magnitude of the reciprocal of the largest magnitude eigenvalue of a particular Hermitian operator. The operator depends on Ȟ and Ȟ0. This result is used to derive a sufficient condition for the perturbation expansion to have a radius of convergence less than one when Ψ01 is a good approximation to Ψj. When we apply the condition to our exchange perturbation theory calculations on HeH+, we find that the expansion must have a radius of convergence less than one. For this system, Ψ01 is a very good approximation to Ψ2. A radius of convergence less than one for the HeH+ calculations implies that the expansions diverge or that they are converging to a state other than Ψ2. We briefly consider the implications of our studies for the existence of a convergent perturbation theory of intermolecular energies.
Verification of form tolerances part I: Basic issues, flatness, and straightness

Abstract The ANSI Y14.5 National Standard on Dimensioning and Tolerancing definition for form tolerances requires the form error of a surface to be less than some set limit. However, most inspectors are interested in the minimum form error, known as the minimum zone solution. To compute the minimum zone flatness, an algorithm must determine the minimum distance between two parallel planes so that all datapoints are between the two planes. Therefore, the minimum zone solution minimizes the maximum error between the datapoints and a reference plane. Current coordinate measuring machine verification algorithms are based on the least-squares solution, which minimizes the sum of the squared errors, resulting in a possible overestimation of the form tolerance. Therefore, while coordinate measuring machine algorithms successfully reject bad parts, they may also reject some good parts. The verification algorithms developed in this set of papers compute the minimum zone solution of a set of datapoints sampled from a part. Computing the minimum zone solution is inherently a nonlinear optimization problem. The proposed algorithms solve a sequence of linear programs that converge to the solution of the nonlinear problem. The linear programs result from a novel combination of coordinate and scaling transformations and do not change the original optimization problem. Therefore, given adequate initial conditions, the sequence of linear programs will converge to the minimum zone solution. Implementation and test results demonstrate the correctness of these formulations. The implementation of these verification algorithms in a production environment can reduce the possibility of rejecting good parts, thereby reducing costs.
Stochastic optimal phase retrieval algorithm for high-contrast imaging

The Princeton University Terrestrial Planet Finder (TPF) has been working on a novel method for direct imaging of extra solar planets using a shaped-pupil coronagraph. The entrance pupil of the coronagraph is optimized to have a point spread function (PSF) that provides the suppression level needed at the angular separation required for detection of extra solar planets. When integration time is to be minimized, the photon count at the planet location in the image plane is a Poisson distributed random process. The ultimate limitation of these high-dynamic-range imaging systems comes from scattering due to imperfections in the optical surfaces of the collecting system. The first step in correcting the wavefront errors is the estimation of the phase aberrations. The phase aberration caused by these imperfections is assumed to be a sum of two-dimensional sinusoidal functions. Its parameters are estimated using a global search with a genetic algorithm and a local optimization with the BFGS quasi-Newton method with a mixed quadratic and cubic line search procedure.
Gastrointestinal phosphate handling in CKD and its association with cardiovascular disease

Increases in serum concentrations of parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) and ultimately phosphate and decreases in 1,25-dihydroxyvitamin D level are thought to play a central role in the progressive nature of kidney disease and the development of cardiovascular disease in patients with chronic kidney disease. The initial changes in PTH and FGF-23 levels are adaptive to maintain serum phosphate concentration and phosphate load within defined levels by increasing urinary excretion of phosphate. Less well appreciated is the unanticipated finding that absorption of phosphate from the gastrointestinal tract is not downregulated in chronic kidney disease. This maladaptive response maintains higher levels of phosphate absorption, thereby contributing to the phosphate burden. Moreover, in response to a low-phosphate diet, as often is prescribed to such patients, gut phosphate absorption may be enhanced, undermining the potential beneficial effects of this intervention. Given the poor response to limiting phosphate intake and the use of phosphate binders, we suggest that research efforts be oriented toward better understanding of the factors that affect phosphate absorption in the gastrointestinal tract and the development of agents that directly inhibit phosphate transporters in the small intestine and/or their associated binding proteins.
Preaching What We Practice: A Study of Revision

In this article, a three-tiered nationwide study of the pedagogical implications of teachers' revision practices in digital writing environments is discussed. The study investigates the use of revision in the personal and professional writing of teachers and the teaching of revision in their own classrooms. During a three year period, data were collected from a sampling frame of 150 National Writing Project Summer Institute sites, resulting in 181 study participants, and included a longitudinal pre- and post-survey (including Likert survey items and open-ended questions), focus group and follow-up questions, and analysis of writing/revision samples. Results indicated that the strategies that teacher-participants historically used when revising their own writing were not the strategies they used with students. After attending the National Writing Project (NWP) Invitational Summer Institute (ISI) and participating in the associated Electronic Anthology (EA), however, the practices that the study's teacher-participants embraced while teaching writing revision to students in their own classrooms aligned more closely with the practices that they employed in editing their own writing.
Interindividual variability in hepatic drug glucuronidation: studies into the role of age, sex, enzyme inducers, and genetic polymorphism using the human liver bank as a model system

The human liver bank has provided an invaluable model system for the study of interindividual variability in expression and activity of the major hepatic UGTs, including UGT1A1, 1A4, 1A6, 1A9, 2B7, and 2B15. Based on studies using UGT-isoform-selective probes, the rank order of activity variability is UGT 1A1>1A6>2B15>1A4 = 1A9>2B7, with coefficient of variation values ranging from 92 to 45%. Liver donor age, sex, enzyme inducers, and genetic polymorphism are factors that have been implicated as sources of this variability in UGT activity. The expression of UGTs prior to, and immediately following, birth is quite limited, explaining the susceptibility of neonates to certain drug toxicities. Old age appears to have minimal effect on UGT function. Sex differences in UGT activity are relatively small and are confined to several UGTs, including UGT2B15, which shows higher activity in males, compared with females. Enzyme inducers, including coadministered drugs, smoking, and alcohol, may increase hepatic UGT levels. Human liver bank phenotype-genotype studies, using UGT-isoform-selective probes have identified common genetic polymorphisms that are predictive of glucuronidation activity in vitro and that were subsequently verified as predictors of probe-drug clearance by glucuronidation in vivo.
A simple activity assay for thrombin and hirudin

Cloning of the thrombin cDNA has made it possible to study thrombin function by site-directed mutagenesis. Quantitative results from studies of thrombin mutants are often hindered by difficulties in assaying the enzyme activity. The high enzyme concentrations required for activity determination by standard methods limit their usefulness to thrombin mutants that cannot be readily produced in large quantities. We have developed a novel method using the synthetic substrate S-2238 and hirudin, a tight-binding inhibitor of thrombin, that allows for the active-site titration of thrombin at concentrations as low as 20 pM, with an error of ≤5%. In addition, hirudin activity can be determined by this method to concentrations as low as 40 pM, with an error of ≤5%.
Dual-Gauge System for Measuring Precipitation: Historical Development and Use

Undercatch of precipitation due primarily to wind is especially pronounced when measuring snowfall by gauges that are not naturally protected, such as in brush or forest clearings. The dual-gauge system can be used to measure all types of precipitation, but was designed specifically to improve the measurement of snowfall under windy conditions. The dual-gauge system uses sets of unshielded and shielded gauge data and an appropriate value of a calibration coefficient in an equation to calculate wind-adjusted precipitation. After three winter seasons of field studies in Idaho, it was determined that 1.8 was the most appropriate value for the calibration coefficient. Analyses of data from other sites in the United States, Canada, and Russia also show that 1.8 is the most reasonable value to use for the calibration coefficient when calculating wind-adjusted snowfall amounts, and that the dual-gauge system also significantly improves the measurement of other forms of precipitation. These studies led to the dev...
Control System Modification of an Electromechanical Pulsatile Total Artifical Heart

A reliable control system is one of the most important characteristics of the electromechanical pulsatile total artificial heart (TAH). Obtaining an error-free procedure is essential for a successful in vivo implantation. To avoid any malfunction of the electrical control system, a modification of the previously designed controller was made to ensure stable pumping without the Hall effect sensor missensing. The installation position of the Hall effect sensor was changed from the top of the housing to the central piece with small magnets being installed in the stabilizer rods. The usage of the Hall effect sensor was chosen as an electrical switch. An in vitro one month running test of the TAH demonstrated adequate hydrodynamic performance with a completely error-free pumping characteristic. The total efficiency of the TAH was 12.6 +/- 1.4% at an 8 L/min outflow and 10.7 +/- 1.0% at a 6 L/min outflow condition.
Structure of transcriptionally active chromatin: radiological evidence for requirement of torsionally constrained DNA

Synthesis of alpha- and beta-globin RNA in DMSO-induced Friend's erythroleukemia cells and synthesis of immunoglobulin gamma- and kappa-chain RNA, total RNA, 5S RNA, and tRNA in mouse myeloma cells (MPC-11) was inhibited by gamma-irradiation. For all RNA species, synthesis decreased nearly exponentially as a function of radiation dose, whereas RNA size distributions, turnover rates, and specific activities of radioactively labeled RNA were affected only insignificantly. D37 values for the loss of synthesis of various RNA species correspond to target sizes ranging from 21,000 to 53,000 kd, or 30-80 kbp of DNA. These target sizes are several-fold larger than the structural genes in question; however, they correspond well with the size of DNA loops, or "domains" constrained by the nuclear matrix. The data suggest that the eukaryotic transcription unit is the torsionally constrained chromatin loop, transcription of which may be inactivated, or significantly reduced by a DNA single-strand break.
Precision Measurements and Fundamental Constants

Recent developments in the techniques for making precision measurements and their use in the determination of the fundamental constants are reviewed. Particularly noteworthy developments are clocks with high stability, the proposed redefinition of the meter in terms of the standard for time, and the increased precision with which electrical standards can be maintained. The relevance of precision measurements to tests of general relativity is briefly discussed.
Achievement Correlates of the Woodcock-Johnson Reading and Mathematics Subtests, KeyMath, and Woodcock Reading in an Elementary Aged Learning Disabled Population

Thirty-two elementary aged learning-disabled students were administered the math and reading subtests from the Woodcock-Johnson Psycho-Educational Battery, KeyMath, and Woodcock Reading Mastery Tests. Grade equivalent scores and standard scores were compared and yielded significant correlations that range from .79 to .93. Mean grade equivalent scores did however significantly differ for the two reading measures but not when standard scores were used. The two math indices yielded nonsignificant grade equivalent scores. Similarities and differences between the instruments are discussed in relation to enhancing the identification of learning disabilities.