cssi/SciSciGPT-SciSciNet huggingface dataset:
Binary strings of finite VC dimension.

Any binary string can be associated with a unary predicate $P$ on $\mathbb{N}$. In this paper we investigate subsets named by a predicate $P$ such that the relation $P(x+y)$ has finite VC dimension. This provides a measure of complexity for binary strings with different properties than the standard string complexity function (based on diversity of substrings). We prove that strings of bounded VC dimension are meagre in the topology of the reals, provide simple rules for bounding the VC dimension of a string, and show that the bi-infinite strings of VC dimension $d$ are a non-sofic shift space. Additionally we characterize the irreducible strings of low VC dimension (0,1 and 2), and provide connections to mathematical logic.
Microstructural dependence on fuel matrix composition in irradiated U-Mo dispersion fuels

Abstract Microstructural characterization of U-Mo dispersion fuel plates irradiated in the RERTR-7 experiment in the Advanced Test Reactor was performed to study the dependence of fuel matrix composition in irradiated U-Mo fuels. The evolution of the fission gas pores and fuel matrix interaction in U-7Mo fuel plates with pure Al and Al-2wt%Si matrix compositions were characterized using optical and scanning electron microscopy in conjunction with image processing techniques. In addition, the combined contribution of Mo composition, fission power, and temperature was studied. Image analysis allowed determination of the fission gas pore (FGP) size, morphology and distribution, as well as the growth of the fuel matrix interaction (FMI) layer. The isolated effect of the Al matrix on the microstructural evolution of U-7Mo fuels revealed that the growth evolution of FGPs as well as the FMI layer is influenced by the matrix. The mean FGP area and FMI growth are 31% and 25% higher in U-7Mo/Al compared to U-7Mo/Al-2Si dispersion fuel, suggesting that U-Mo dispersion fuel with a thicker FMI layer (low thermal conductivity) has the potential to grow larger FGPs in the U-7Mo, possibly because of the higher temperature in the fuel meat. Previous studies have shown that there is an inverse relationship between Mo composition and the FMI, as a result, the microstructural response of U-10Mo and U-7Mo was also investigated and compared. Because the FMI layer thickness is 40% higher in the U-10Mo specimen than the U-7Mo specimen, the combined effect of increased fission power, and temperature for the U-10Mo sample may counteract the propensity of U-Mo fuels with increased Mo content to have a decreased amount of FMI.
miR-71 mediates age-dependent opposing contributions of the stress-activated kinase KGB-1 in Caenorhabditis elegans

Studying the evolutionary processes that shaped aging offers a path for understanding the causes of aging. The antagonistic pleiotropy theory for the evolution of aging proposes that the inverse correlation between age and natural selection strength allows positive selection of gene variants with early-life beneficial contributions to fitness despite detrimental late-life consequences. However, mechanistic understanding of how this principle manifests in aging is still lacking. We previously identified antagonistic pleiotropy in the function of the Caenorhabditis elegans JNK homolog KGB-1, which provided stress protection in developing larvae, but sensitized adults to stress and shortened their lifespan. To a large extent, KGB-1's contributions depended on age-dependent and opposing regulation of the stress-protective transcription factor DAF-16, but the underlying mechanisms remained unknown. Here, we describe a role for the microRNA miR-71 in mediating effects of KGB-1 on DAF-16 and downstream phenotypes. Fluorescent imaging along with genetic and survival analyses revealed age-dependent regulation of mir-71 expression by KGB-1-upregulation in larvae, but downregulation in adults-and showed that mir-71 was required both for late-life effects of KGB-1 (infection sensitivity and shortened lifespan), as well as for early life resistance to cadmium. While mir-71 disruption did not compromise development under protein-folding stress (known to depend on KGB-1), disruption of the argonaute gene alg-1, a central component of the microRNA machinery, did. These results suggest that microRNAs play a role in mediating age-dependent antagonistic contributions of KGB-1 to survival, with mir-71 playing a central role and additional microRNAs potentially contributing redundantly.
Print vs. digital : the future of coexistence

Introduction. The Impact of Evolving Information-Seeking Behaviors Upon Research Libraries: A Case Study. Beyond Coexistence: Finding Synergies Between Print Content and Digital Information. Shaping Our Space: Envisioning the New Research Library. JSTOR: Past, Present, and Future. The Library and the Newsstand: Thoughts on the Economics of News Preservation. The Digital Difference in Reference Collections. The Cooperative Conundrum in the Digital Age.The End of Print Journals: (In)Frequently Asked Questions. Index. References.
Implications of discordant findings between hepatic angiography and cross‐sectional imaging in transplant candidates with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide.1 Treatment options depend on the tumor stage and liver function.2 Resection, thermal ablation, and liver transplantation are the only potentially curative options.3 Candidacy for transplantation is based on the Milan criteria [1 lesion ≤5 cm or 2 to 3 lesions ≤3 cm in diameter without macrovascular invasion as determined by multiphase contrast-enhanced (CE) computed tomography (CT) or magnetic resonance imaging (MRI)].4 Liver-directed therapy, such as transarterial chemoembolization (TACE) and thermal ablation, is offered to patients with unresectable HCC confined to the liver as a bridge to transplantation.5,6 Local and distal tumor recurrences as well as the presence of a residual disease after liver-directed therapy are common and are among the causes of dropout from the transplant list and high mortality.7,8 Therefore, identifying and treating recurrent lesions is imperative for maintaining patients’ eligibility while they are awaiting transplantation.5 The diagnosis of HCC is often based on a characteristic tumor appearance on CE CT or MRI. Tissue diagnosis is usually not required.3,9 Because CE CT and MRI scans reliably detect only HCC nodules larger than 1 cm and may underestimate the tumor stage,10,11 an alternative diagnostic imaging tool that can detect additional lesions may improve clinical outcomes.12 One diagnostic tool that is already employed for some patients with HCC is hepatic digital subtraction angiography (DSA), which is performed in conjunction with arterial therapies used to treat HCC. The sensitivity of DSA for HCC detection has been reported to be in the range of 55% to 77%13–15 and is better for larger HCC lesions.16 The sensitivity of CE CT and MRI for HCC detection has been described to be in the 65% to 84%10,11,14,15 and 62% to 76% ranges,10,11,14 respectively. In comparison, the sensitivity for the demonstration of ethiodized oil (lipiodol) uptake after TACE in HCC lesions on plain post-TACE radiographs has been reported at 94%,17 whereas the sensitivity of postlipiodol CT for the detection of hypervascular HCC lesions treated with TACE may approach 100%.18 Angiographic images sometimes demonstrate hypervascular foci in the liver that outnumber the lesions detected by CE CT or MRI.19 Conversely, sometimes there is no angiographic correlate to hypervascular lesions detected on cross-sectional imaging. The clinical significance of these “discordant” findings is unclear. The purpose of this study was to retrospectively review and correlate findings during hepatic DSA obtained at the time of TACE with preceding CE CT and/or MRI in patients with HCC listed for liver transplantation in order to identify patients with discordant lesions and to determine whether the presence of such lesions led to adverse clinical outcomes, such as removal from the transplant list and post-transplant tumor recurrence.
Adaptive/learning control of large space structures - System identification techniques

Techniques developed for the control of aircraft under changing operating conditions are used to develop a learning control system structure for a multi-configuration, flexible space vehicle. A configuration identification subsystem that is to be used with a learning algorithm and a memory and control process subsystem is developed. Adaptive gain adjustments can be achieved by this learning approach without prestoring of large blocks of parameter data and without dither signal inputs which will be suppressed during operations for which they are not compatible. The Space Shuttle Solar Electric Propulsion (SEP) experiment is used as a sample problem for the testing of adaptive/learning control system algorithms.
Biological uptake of phosphorus by activated sludge.

The ability of activated sludge to remove phosphates was studied by adding carrier-free 32P to raw sewage and measuring incorporation of the radioactivity into the cells over a period of time. Radioisotope determinations indicated that 48% of the 32P radioactivity was removed by 12 hr. However, chemical methods indicated that only 30% of the orthophosphate apparently disappeared from the sewage during this period. Experiments with sludge prelabeled with 32P indicated that considerable phosphate turnover occurred. The cells released large amounts of radioactivity as they were incorporating fresh phosphates. Starvation in isotonic saline for 18 hr caused the sludge to dump phosphate. When introduced into fresh sewage containing 32P, the starved sludge removed about 60% of the radioactivity in 6 hr with little phosphate turnover. The ability of sludge to remove 32P was inhibited approximately 83% by 10−3m 2,4-dinitrophenol. This inhibition was at the expense of the cell fraction that contained ribonucleic acid and deoxyribonucleic acid. The sludge cells released orthophosphate when exposed to the chemical agent. Experiments using 45Ca indicated that calcium phosphate precipitation plays a minor role in phosphate removal under our experimental conditions.
The BAPCPA's Chilling effect on Debtor's Councel

Introduction 1333 I. New Duties Under BAPCPA 1335 II. Attorney Liability Under BAPCPA 1336 III. Automatic Dismissal of Bankruptcy Cases 1339 A. Failure to Request Credit Counseling 1339 B. Failure to File Documents 1341 IV. Learning Other States’ Exemption Laws 1342 Conclusion 1344
Metallo-enzymes Released from Escherichia coli by Osmotic Shock II. EVIDENCE THAT 5'-NUCLEOTIDASE AND CYCLIC PHOSPHODIESTERASE ARE ZINC METALLOENZYMES

Abstract Escherichia coli cells were grown in the presence of radioactive 65Zn and subjected to osmotic shock. Two enzymes, 5'-nucleotidase and cyclic phosphodiesterase, were purified from the shock fluid. Other evidence indicates that 5'-nucleotidase was brought to a stage of purification corresponding to that of a homogeneous protein. The purifications were accompanied by a considerable enrichment with respect to 65Zn, which could not be removed by dialysis. Superimposable peaks of enzyme activity and 65Zn were observed for both enzymes. Cyclic phosphodiesterase and 5'-nucleotidase were inactivated after prolonged exposure to ethylenediaminetetraacetate and partial reactivation was achieved with Zn++. Treatment of 5'-nucleotidase with acid caused loss of activity associated with release of 65Zn. The preparation could be reactivated by low concentrations of each of several divalent metal ions. It is suggested that cyclic phosphodiesterase and 5'-nucleotidase are metalloproteins and possibly zinc metalloenzymes.
Finite element modeling of cellular responses of gap junction connected osteocytes under extremely low-frequency electromagnetic fields

Bone cells have been known to sense extremely weak magnetic fields with very small potential gradients. Several interaction mechanisms have been proposed, in order to explain this phenomenon, but, none of them have yet been able to explain this satisfactorily. A simple arrangement of osteocytes, connected by gap junctions via their processes have been modeled, under the influence of a weak electromagnetic field. The effect of varying the gap junctional conductance has been considered in this model (which corresponds to the degree to which the gap junctions are open, or closed). A finite element solver (FEMLAB) that considers the conductivity and permittivity of the membranes, intra and extracellular fluid, and the gap junctions has been used. A significant difference in the current density distribution and magnitude is observed for a large change in gap junctional conductance.
Approximation Algorithms for the Traveling Purchaser Problem and its Variants in Network Design

The traveling purchaser problem is a generalization of the traveling salesman problem with applications in a wide range of areas including network design and scheduling. The input consists of a set of markets and a set of products. Each market offers a price for each product and there is a cost associated with traveling from one market to another. The problem is to purchase all products by visiting a subset of the markets in a tour such that the total travel and purchase costs are minimized. This problem includes many well-known NP-hard problems such as uncapacitated facility location, set cover and group Steiner tree problems as its special cases.We give an approximation algorithm with a poly-logarithmic worst-case ratio for the traveling purchaser problem with metric travel costs. For a special case of the problem that models the ring-star network design problem, we give a constantfactor approximation algorithm. Our algorithms are based on rounding LP relaxation solutions.
On device-based identity management in enterprises

This paper focuses on the management of device-based identities within enterprises. This is a key requirement in enterprises where the identities of devices have become as important as the identities of humans (users) to grant access to enterprise resources. In this context, access control systems need to understand which devices are being used to access resources, by whom and in which contexts. Trust in managed devices' identities is an important first step to enable this. Most related commercial solutions are deployed at the network level. Instead, we focus at the application/service level to leverage current enterprise identity management solutions, used to manage users' identities. We investigate requirements and related issues. We introduce an initial approach and describe our related solution. A working prototype (proof-of concept) has been fully implemented by extending HP OpenView Identity Management solutions and using trusted computing-enabled devices. This is work in progress: we aim at setting the context and discussing our current status and next steps.
Tight Co‐Degree Condition for Packing of Loose Cycles in 3‐Graphs

We show that for every even integer there is n0 such that, if H is a 3-uniform hypergraph on , vertices such that the minimum co-degree of H is at least , then H can be tiled with copies of a loose cycle on s vertices. The co-degree condition is tight.
A conceptual framework for the study of dance teaching.

In order to understand and improve the dance teaching-learning process it is first necessary to design a conceptual framework which will contain and sequence the relevant elements. The framework presented here meets certain key criteria and provides the infrastructure for an instructional theory for dance. It is patterned on the Presage-Process-Product model, yet is sufficiently comprehensive to be applied to a variety of dance teaching settings. So long as the dance teaching role is critical to the evolution and preservation of dance in society, research based on this framework is needed to generate practical and theoretical pedagogical guidelines.
The use of acute ethanol administration as a tool to investigate multiple memory systems

The discovery of multiple memory systems supported by discrete brain regions has been one of the most important advances in behavioral neuroscience. A wealth of studies have investigated the role of the hippocampus and related structures in supporting various types of memory classifications. While the exact classification that best describes hippocampal function is often debated, a specific subset of cognitive function that is focused on the use of spatial information to form hippocampal cognitive maps has received extensive investigation. These studies frequently employ a variety of experimental manipulations including brain lesions, temporary neural blockade due to cooling or discrete injections of specific drugs. While these studies have provided important insights into the function of the hippocampus, they are limited due to the invasive nature of the manipulation. Ethanol is a drug that is easily administered in a non-invasive fashion, is rapidly absorbed and produces effects only in specific brain regions. The hippocampus is one brain region affected by acute ethanol administration. The following review summarizes research from the last 20 years investigating the effects of acute ethanol administration on one specific type of hippocampal cognitive function, namely spatial memory. It is proposed that among its many effects, one specific action of acute ethanol administration is to produce similar cognitive and neurophysiological effects as lesions of the hippocampus. Based on these similarities and the ease of its use, it is concluded that acute ethanol administration is a valuable tool in studying hippocampal function and multiple memory systems.
Retroviral analysis of cardiac morphogenesis: discontinuous formation of coronary vessels.

Cellular progenitors of the coronary vasculature are believed to enter the chicken heart during epicardial morphogenesis between stages 17 and 27 (days 3-5) of egg incubation. To trace cells which give rise to the coronary arteries in vivo, we applied retroviral cell tagging procedures and analyzed clonal populations of vascular smooth muscle, endothelium, and connective tissue in the hearts of post-hatch chickens. Our data provide direct proof that (i) vascular smooth muscle progenitors begin to enter the heart at stage 17, substantially after the heart begins propulsive contractions; (ii) cardiac myocytes, vascular smooth muscle, perivascular fibroblasts, and coronary endothelial cells all derive from independent precursors when these cells migrate into the heart; (iii) endothelial cells of the coronary vessels have a different clonal origin than endothelial cells of the endocardium; (iv) coronary arteries form by the coalescence of discontinuous colonies (i.e., in situ vasculogenesis), each derived from a founder cell tagged at the time of retroviral injection (stages 17-18); and (v) coronary arteries contain discrete segments composed of "polyclones." These studies indicate the feasibility of gene targeting to coronary progenitors through the use of recombinant retroviruses.
N-nitrosamine formation from atrazine.

Previous studies have focused on N-nitroso derivatives of relatively non-persistent pesticides or pesticides that form unstable N-nitroso derivatives. We feel that more persistent pesticides or their degradative products capable of forming N-nitroso derivatives should be investigated. Also pathways of degradation, both chemical and biological, should be elucidated.
Effect of Hydroacoustic Cavitation Treatment on the Spiral Processing of Bituminous Coal

Testing was conducted to evaluate the effects of hydroacoustic cavitation (HAC) treatment on spiral separation when processing nominal −1500 µm Illinois-basin bituminous coal. Cavitation was produced either by flow through an ultrasonic resonator chamber or enhanced cavitation by initial flow through a cavitation box followed by flow through the ultrasonic chamber. After treatment, the slurry was passed through a hydrocyclone for desliming, and the underflow stream was used as spiral feed. Spiral tests were carried out using a two-stage spiral at three volumetric flow rates for different HAC treatment conditions. HAC treatment reduced the overall size distribution of the spiral feed material. Likewise, desliming of the treated material led to a reduction in the ash values for each size interval. For example, after HAC treatment, the ash value of the deslimed material was reduced to 25% compared to 41% for the untreated deslimed material. Subsequent spiral separation of the treated material produced clean ...
The synthesis of prostaglandins by bovine cerebral microvessels

Abstract Bovine cerebral microvessels (arterioles and capillaries) synthesize prostacyclin (PGI 2 , measured as 6-keto PGF 1α ), PGF 2α , PGE 2 and thromboxane A 2 (measured as TXB 2 ) when incubated in glucose-bicarbonate buffer for 30 minutes. Rapid freezing and thawing decreased the subsequent synthesis of 6-keto PGF 1α by cerebral microvessels and raised the basal levels of this metabolite within the incubation medium. At low concentrations, the addition of arachidonic acid (0.16 μM) did not stimulate prostacyclin or prostaglandin production; at higher concentrations (16 μM), the synthesis of PGI 2 and PGF 2α was inhibited. Activation of lipase by the peptide melittin stimulated the synthesis of all arachidonic acid metabolites to the same extent. Thus cerebral microvessels deacylate cellular lipids and metabolize endogenous arachidonic acid to form prostaglandins, prostacyclin and related compounds as previously demonstrated in larger blood vessels. The synthesis and release of these molecules may be important for modulating the tone and reactivity of small blood vessels within the brain.
Scientific Assessment Of The Clinical Utility Of Phosphor Plate Computed Radiography

Medical innovations require rigorous testing on a number of levels to determine their applicability to clinical practice. This presentation describes our experiments with phosphor-plate digital radiography to determine whether this technology can replace conventional radiography for selected applications of urologic and chest radiology. While our work predominantly focuses on technical efficacy, there are implications for possible improvements in patient outcomes and cost-effectiveness.
Optical absorption spectra of surface or interface states in hydrogenated amorphous silicon

The optical absorption of doped and undoped hydrogenated amorphous silicon (a‐Si:H) films ranging from 5 nm to 10 μm was measured using photothermal deflection spectroscopy. The absorption spectra show that there is a high defect layer associated with the surface or interface of the film. From comparison of defect absorption and dangling bond spin densities, it is found that a‐Si:H films which have ∼1015 bulk defects/cm3 exhibit surface or interface layers with ∼1012 dangling bonds/cm2.
Design limitations for superconducting A/D converters

This paper reviews the principle of A/D conversion using superconducting quantum interference and describes the results obtained with this technique At an accuracy of four or six bits the design of such converters is straightforward. Higher accuracy requires careful consideration of numerous design constraints including critical current uncertainty, power supply regulation, turn-on-delay, signal line crosstalk, and the threshold curve critical points. The implications of these constraints are analyzed with respect to an example design for an 8-bit converter.
Regeneration in the adult mammalian CNS: guided by development

In the past year, the roles and mechanisms of molecules involved in cell survival (glial-derived neurotrophic growth factor), growth cone guidance (netrins and semaphorins), axonal outgrowth and sorting (neural cadherin, polysialylated neural cell adhesion molecules, and L1), and neuronal connectivity (cell adhesion molecules, dystroglycan, and agrin) have been described during development and, to a limited extent, in the mature CNS. Evidence is now emerging that some developmental events, such as the expression of polysialylated neural cell adhesion molecule and L1, are recapitulated during adult CNS regeneration. These results suggest new avenues to address more accurately the challenges of axonal regrowth in the adult mammalian CNS.
Fast Speech and the Origin of the Standard English Verbal Suffix -s

It is suggested in this paper that the problematic third person singular present indicative verbal ending -(e)s of Standard English originated as a fast speech variant of the earlier suffix -eth. This hypothesis is supported by the findings of some recent studies of the largely unexplored phenomena of fast speech and by direct and indirect evidence concerning the linguistic, stylistic, and social significance of the desinence during the Early Modern English Period.
On vulnerability and transformative leadership: an imperative for leaders of supervision

Supervision as a field, in the main, remains susceptible and thus vulnerable to various forces, ideological and otherwise, that constrain its ability to play a significant role in instructional improvement and thus in educational leadership. Adherence to inspectional and faultfinding supervision under the guise of standards‐based and other practices has serious consequences for the improvement of teaching and student achievement. Unless those of us who are committed to the study of supervision in higher education, as well as school administrators and other practitioners who supervise teachers, are ready, willing and able to assert responsibilities for best practice in supervision through transformational leadership the educational landscape will remain in its transitory and vulnerable state, inconsequential at best, destructive at worst. Relying on the social and educational critiques of Robert Goldhammer and Jules Henry, this article seeks to raise the consciousness of those committed to instructional ex...
Gain indexing schemes for low-thrust perturbation guidance

Two perturbation guidance schemes, time-to-go guidance and minimum-distance guidance, are re-examined in the context of a low-thrust orbit transfer problem. The two schemes, which use different techniques for indexing feedback gains, are shown to be comparable in performance. Both schemes are found to produce terminal state errors that are orders of magnitude smaller than those obtained in several previous studies. Various small modifications or enhancements of the algorithms are thought to account for a portion of the dramatic improvement in results. The problem investigated is a hypothetical Earth to Mars orbit transfer with six state variables, two control variables, and six terminal state constraints.
Adrenal Hemorrhagic Effect of Thorotrast

SummaryThorotrast administered intravenously has been shown to produce bilateral adrenal hemorrhage in rabbits. This effect is directly related to the dosage of Thorotrast employed, and is more frequently observed in larger rabbits than in small rabbits. Adrenal hemorrhage was dependent upon the particulate material in Thorotrast (thorium dioxide) and was not produced by the dextrin medium alone. The possible role of at least 3 demonstrated activities of Thorotrast—adrenal stimulation, production of multiple coagulation defects, and vascular wall injury is discussed.
Energetics of meal patterns in rats.

Abstract Meal patterns in rats were examined as functions of the caloric density and availability of the diet. Three diets were used, a standard laboratory diet (3.6 kcal/g), a calorically diluted diet (2.7 kcal/g), and a calorically concentrated diet (4.5 kcal/g). After obtaining ad lib measures of meal patterns on each diet availability of food was constrained by requiring the rats to complete fixed ratio requirements of barpresses to obtain access to a meal. On all 3 diets, meal frequency decreased, while meal size and duration increased as functions of the ratio requirement. Under ad lib conditions and low ratio requirements, in comparison to the standard diet, meal frequency was greater on the diluted diet and less on the concentrated diet. Meal size did not vary as a function of diet on low ratio schedules. At high ratio requirements, rats continued to maintain caloric intake on the diluted diet by increasing meal frequency. On the concentrated diet, however, rats maintained intake at high ratio values by decreasing meal size rather than meal frequency. The results indicate that the rat can adopt a variety of strategies to solve the problem of controlling energy intake constant across the daily feeding cycle.
Untersuchungen zur RÜckbildung von Minderungen des Mikrophonpotentials (MP) nach Schallbelastungen

Zweck der geschilderten Untersuchungen war es, Aufschlus Uber Besonderheiten der RUckbildung und RUckbildungsfahigkeit einer MP-Minderung nach Schallbelastung mit Intensitaten zu erhalten, die oberhalb der von uns frUher angegebenen kritischen Belastungsschwelle fUr das Haarzellorgan des Meerschweinchens lagen.
Axial solid distribution in gas‐solid fluidized beds

Γ-ray attenuation method was applied to determine the axial fluidizing bulk density profile for an air-solid aggregative fluidized bed. Except for beds fluidized at very high air velocities two distinct density zones were noted. The density of the bed in the lower portion of the column was relatively constant for a particular set of operating conditions and did not vary with bed height. The density in the top portion of the bed fell rapidly with bed height. The average density of the lower zone was correlated as a function of the operating variables. The density in the top zone was represented by a one-tail normal distribution curve. A somewhat better correlation was obtained by a two-parameter equation at high air velocities. The effects of operational variables, such as air velocity, static bed height, particle size, and particle-size distribution on these correlations were investigated. Friction-factor correlations based on two different definitions of bed height were also obtained.
economic freedom for africa

Why have freedom and the liberal economy declined in Africa since independence? Charles Mensah of the independent Institute of Economic Affairs in Ghana offers an economic explanation.
Finite-element analysis of a constant-force solenoid for fluid flow control

A model for constant-force solenoids based on the finite-element method is presented. The total force exerted by the solenoid is calculated and compared with test results. The force calculation algorithm is also used to determine the force distribution pattern around the plunger surface, and to provide a detailed analysis of the solenoid structure. The model was successfully implemented to improve a solenoid design. The finite-element package is shown to be a powerful design tool, capable of accurate performance prediction. The analysis process shows the importance of the truncated-cone shape of the plunger, of balancing the forces produced by the tapered and flat portions of the plunger surface, and of matching the respective positions of the plunger and of the facing pole. >
Plankton respiration and biomass as functional indicators of recovery in restored prairie wetlands

Abstract Reliable ecological indicators of wetland integrity are necessary for assessing recovery of restored wetlands; yet, little consensus currently exists on which indicators are most appropriate. We employed indicators derived from simple, standard measures of ecosystem function selected on the basis of ecological succession theory developed by [Science 164 (1969) 262; Bioscience 35 (1985) 419], which suggests that respiration:biomass ratios should increase in disturbed systems due to the diversion of energy from growth to maintenance. This hypothesis holds potential for the development of a simple ecological indicator and therefore was tested among prairie wetlands restored after drainage disturbance. No difference was observed in respiration:biomass ratios in restored wetlands and reference wetlands designated as controls. Plankton respiration or biomass may be poor indicators of disturbance because plankton responds quickly to re-establishment of a wetland hydrology regime and/or because different plankton species may have redundant function. We suggest employing more revealing assessment techniques that employ simultaneous examination of ecosystem structure and function to better characterize subtle or lingering effects of wetland disturbance after restoration.
Satisfaction with Past Financial Performance, Risk Taking, and Future Performance Expectations in the Family Business

Prior research has shown that past financial performance and risk-taking proclivity influence firms' goal setting and future performance expectations. In this study, we analyze how such factors manifest themselves in the context of the family business. Drawing from the behavioral theory of the firm, we argue that owners–managers of family firms satisfied with their past financial performance will correspondingly upgrade their future performance expectations. Based on strategic reference points theory, we also propose that satisfaction with past performance in family firms will be negatively associated with risk taking. Finally, we conjecture that family firms may exhibit heterogeneity in their risk orientation so that greater risk taking will be positively associated with family firms' future performance expectations. The results of structural equation modeling analysis of two combined surveys of family firms supported the hypotheses.
New molecular techniques for chromosome analysis

The advent of molecular genetic technology has significantly advanced knowledge about the structure of chromosomes and their behaviour during meiosis and mitosis, as well as delineating cytogenetic aberrations that cannot be identified by conventional chromosome analysis. Molecular cytogenetics, the visualization of genetic loci using the dynamic recombinant technology of fluorescence in situ hybridization (FISH), now provides the obstetrician and gynaecologist with increasingly important diagnostic and prognostic information heretofore unavailable. The technical principles underlying FISH are briefly discussed. Emphasis is placed on the clinical applications of FISH and technologies derived from FISH, in particular comparative genome hybridization, microdissection FISH and multiplex FISH. These technologies play increasingly significant roles in preimplantation and prenatal genetic diagnosis, in the identification of microdeletion syndromes, cryptic translocations and marker chromosomes, and in defining chromosome mosaicism. FISH and related technologies also constitute essential diagnostic modalities in follow-up of organ transplantation, in a variety of haematological disorders and in determining the amplification of oncogenes associated with specific forms of cancer and neoplasia.
Conversion of Fuel-Nitrogen in the Primary Zones of Pulverized Coal Flames

Complete distributions of all major products and nitrogen species are reported for the oxidative pyrolysis and combustion of premixed suspensions of subbituminous, Pittsburgh No. 8 hvA bituminous, and a low-volatile bituminous coal after 150 ms. As inlet O 2 levels were progressively increased from 0 to 15% in successive tests, the process chemistry moved through oxidative volatiles pyrolysis, volatiles combustion, soot combustion, and char oxidation. However, the different fuel components were consumed sequentially only with the low-volatility coal. Char, soot, and noncondensible fuels burned simultaneously with the subbituminous coal and, to a lesser degree, with the Pittsburgh No. 8. Consequently, hydrocarbon gases from these coals, particularly CH 4 and C 2 H 2 , were present while most of the char and its residual fuel-N was converted into gases. With all coals, the persistence of gaseous hydrocarbons profoundly affects the conversion of all fuel-N species in the gas phase. As long as detectable amounts of CH 4 and C 2 H 2 are present, NO is absent with all coal types and total fixed nitrogen (TFN = HCN + NH 3 + NO) is composed of only HCN with both bituminous coals, plus appreciable amounts of NH 3 during intermediate stages with the low-rank coal. But after the hydrocarbons are consumed, HCN and NH 3 vanish and most of the remaining char-N and soot-N are converted into NO, so TFN is composed of only NO. The extent of carbon conversion up to the NO inception point is the primary coal rank index for early NO production in coal flames, falling from 38% with the subbituminous to 12% with the low-volatility coal.
Rule‐Based Expert Systems and Linear Models: An Empirical Comparison of Learning‐By‐Examples Methods*

Building models of expert decision-making behavior from examples of experts’ decisions continues to receive considerable research attention. In the 1960's and 70's, linear models derived by statistical methods were studied extensively. More recently, rule-based expert systems derived by induction algorithms have been the focus of attention. Few studies compare the two approaches. This paper reports on a study that compared linear models derived by logistic regression with rule-based systems produced by two induction algorithms—ID3 and the genetic algorithm. The techniques performed comparably in modeling the experts at one task, graduate admissions, but differed significantly at a second task, bidder selection.
Organic fouling inhibition on electrically conducting carbon nanotube–polyvinyl alcohol composite ultrafiltration membranes

Abstract Robust and electrically conductive thin films (2500 S/m) made of cross-linked poly(vinyl alcohol) and carboxylated multi-walled carbon nanotubes (PVA–CNT–COOH) were synthesized via a sequential deposition and cross-linking method. The PVA–CNT–COOH modified membranes were then used in an electrofiltration cell in which the effects of applied potentials on fouling of high concentrations (3–5 g/L) of alginic acid (AA) were studied. It was demonstrated that after 100 min of operation while applying −3 V and −5 V, the change in operating pressure was reduced by 33% and 51%, respectively, compared to application of no voltage. Increase in ionic strength resulted in overall higher fouling rates, where the application of −5 V resulted in a pressure change reduction of 43% compared to no application of potential. A modified Poisson–Boltzmann equation used in a DLVO-type theory demonstrated that at the applied potentials, electrostatic interactions produced significant repulsive forces between the membrane surface and the charged organic foulant. Calculations at experimental conditions demonstrated the pure AA aggregates would be strongly repulsed away from membrane surface. In synthetic wastewater the repulsion force is greatly reduced, resulting in overall reduced fouling inhibition.
Analysis of convective flow effects on the performance of an intercalated-spiral alternate-dead-ended hollow fiber bioreactor

The model analysis of a convective-flow dominant intercalated-spiral alternate-dead-ended hollow fiber bioreactor is presented. Previous work with a segregated radial flow model is compared to a more rigorous two-dimensional analysis of the bioreactor fluid mechanics, substrate consumption and transient cell growth. Analytical solutions for the radial and axial velocities and pressure distributions are derived by solving the coupled continuity and momentum equations in the extracapillary space and the arterial and venous fiber lumina and membranes. The validity of the radial one-dimensional model for small pressure moduli (≤ 1) are substantiated by the present work. Limitations of the previously developed one-dimensional model are revealed for larger pressure moduli when the axial velocity through the cell growth region dominates. Results are generated using the pressure modulus, the wall Peclet number and the Thiele modulus as parameters. This more rigorous analysis substantiates previous findings that the alternate-dead-ended design improves bioreactor performance via an enhanced radial convective flux into the cell growth region.
Epicatechin carbonyl-trapping reactions in aqueous maillard systems: Identification and structural elucidation.

Recently, our group reported via labeling experiments that epicatechin in Maillard reaction aqueous glucose−glycine model systems formed adduct reaction products with C2, C3, and C4 sugar fragments. In the current study, we investigated the identity of the sugar fragment precursors responsible for adduct generation by directly comparing the liquid chromatography−mass spectrometry properties of these reported epicatechin (EC)−sugar fragments adducts with those generated from reactions consisting of only EC and well-known Maillard-generated glucose fragments (i.e., glyoxal, glycolaldehyde, methylglyoxal, glyceraldehyde, etc.). The structural properties of an EC−methylglyoxal adduct reaction product were also analyzed by NMR. The most likely precursors for the C2, C3, and C4 sugar moiety of the EC−sugar fragment adducts were identified as glyoxal, hydroxyacetone, and erythrose, respectively. 1H NMR analysis of the EC−methylglyoxal indicated that the analyte underwent rapid conformational/constitutional excha...
SHEAROGOVEA, A NEW GENUS OF CYPHOPHTHALMI (ARACHNIDA, OPILIONES) OF UNCERTAIN POSITION FROM OAXACAN CAVES, MEXICO

Abstract Shearogovea gen. nov. is erected for Neogovea mexasca Shear, 1977, a troglobitic cyphophthalmid species from a cave system in Oaxaca, Mexico. The new genus does not show affinity to Neogovea Hinton, 1938, as it lacks the characteristic toothed claw of leg II or the fusion of the coxae of legs II to those of legs III (which are in turn fused to coxae of legs IV). Shearogovea gen. nov. is probably not related to other Neotropical neogoveid genera, but its exact phylogenetic position remains unresolved.
LETHAL EFFECTS OF RESERPINE PLUS PHYSOSTIGMINE AND NEOSTIGMINE IN MICE

SUMMARY 1. The interaction between the reversible cholinesterase inhibitors, physostigmine and neostigmine and reserpine was studied. 2. A combination of reserpine plus a cholinesterase inhibitor significantly increased lethality in adult male Swiss-Webster mice above that caused by either neostigmine, physostigmine, or reserpine alone. 3. Methscopolamine completely reversed this effect. 4. It would appear that the presence of the antiadrenergic agent, reserpine, increases the toxicity of cholinomimetic agents. 5. The above results may have clinical significance, since reserpine and cholinesterase inhibitors are used in the practice of medicine.
TPD studies of vanadium oxide films deposited on gold

Temperature-programmed desorption (TPD) can be used to study reactions on vanadium oxide films deposited onto gold foil by evaporation. Scanning electron microscopy, X-ray diffraction, laser Raman spectroscopy, and Auger electron spectroscopy reveal that these films consist of micron-sized crystallites of fully oxidized V2O5. In vacuum, molecular O2 desorbs from the films above 775 K, a temperature at which surface oxygen lost through desorption can be replaced through surface segregation of bulk oxygen. However, after activated hydrogen is adsorbed, surface oxygen can be removed at much lower temperatures as H2O. Water desorbs at 425 K without leaving surface oxygen vacancies. After the adsorption of ethanol and ethylene, CO and CO2 are the primary desorption products (peak desorption temperatures at 670–720 K) although small amounts of acetaldehyde are also observed. This behaviour is related to that found in the catalytic oxidation of ethanol.
Transmission electron microscopy observations of misfit dislocations in GaAsP epitaxial films

Transmission electron microscopy observations have been made of misfit dislocation structures in GaAsP epitaxial films in foils both parallel to (1) the interface between the epitaxial film and the substrate and (2) the {1 1 1} glide planes. These observations support a near surface source mechanism of dislocation multiplication for relief of the epilayer misfit. It is also suggested that the recently observed surface reconstruction in the III-V compounds might allow for an easier nucleation of dislocations at the surface than hitherto thought. Furthermore, an efficient Lomer dislocation has been observed forming from two 60° glide dislocations thus supporting the hypothesis that all dislocations found in these foils, including the sessile Lomer type, originate from a glide process.
Synthesis of lanthanide carbonates

Abstract The normal carbonates of La3+, Nd3+, Sm3+, Eu3+, Gd3+, Dy3+ and Ho3+ have been synthesized by the reaction of an aqueous suspension of the lanthanide oxide, M2O3, with CO2 under supercritical conditions. The effect of temperature, between 25 and 50 °C, and pressure, from 68 to 240 atm, on the extent of conversion of the oxide to the carbonate has been investigated. Yields of 95% or better of the normal carbonates were obtained at a pressure of 100 atm after the reaction was carried out for 1 h. The higher the concentration of CO2 dissolved in the aqueous phase, the higher the yield. The oxides of Pr3+, Tb3+, Er3+ and Yb3+, as well as ZrO2 and CeO2, either did not react at all or gave very low yields of carbonates under the experimental conditions that were employed.
An Empirical Method of Estimating Raingage and Radar Rainfall Measurement Bias and Resolution

Abstract This paper presents new methods of estimating the bias and the resolution of radar and raingage area average rainfall measurements over a defined area when both devices are employed simultaneously. The bias of raingage measurements for various rainfall amount ranges is estimated from published data, and the bias for radar measurement is then determined through comparison with the raingage recordings. The resolution estimations are carried out using error variance analysis on corresponding sets of gage and radar observations. The assumptions underlying this technique demand a uniform terrain for rainfall measurements, a large sample of cases, and, for one of the analysis options, a high correlation between radar and gage rainfall measurements. The procedure is illustrated using the gage and radar rainfall data from the second phase of the Florida Area Cumulus Experiment (FACE-2). The gage sampling error variance estimations for various rainfall amount categories using an empirical radar-derived me...
Noradrenergic reinnervation of the rat spleen following chemical sympathectomy with 6-hydroxydopamine: pattern and time course of reinnervation.

Abstract The time course and pattern of reinnervation of noradrenergic (NA) sympathetic nerve fibers into the spleen following acute chemical sympathectomy with the catecholamine neurotoxin 6-hydroxydopamine (6-OHDA) was examined in young adult male Fischer 344 rats using glyoxylic acid fluorescence histochemistry and neurochemical measurement of NE. Reinnervation proceeds initially along the splenic artery as it enters the hilus (1–5 days), extends into the hilar region (5–10 days), and later proceeds into the regions distal to the hilus (21–56 days), suggestive of orderly growth from the hilar region to distal regions. In all 6-OHDA-treated spleens, the compartmentation of NA innervation was similar to that observed in saline-injected controls, but the density of NA nerve fibers in these compartments differed according to the distance from the hilus. By 56 days postlesion, regions distal to the hilar blood vessels contained fewer NA profiles than their age-matched controls, suggesting that the anatomical process of reinnervation does not restore the density of fibers in a fashion identical to that of nondenervated controls. In contrast, splenic NE concentration at 56 days postdenervation did not differ from the concentration seen in nondenervated control spleens. We suggest that functional restoration of splenic innervation may involve metabolic and receptor compensation for the lack of complete fiber regrowth into regions of white pulp distal from the hilus.