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Showing papers by "Oklahoma State University–Stillwater published in 1990"


Proceedings ArticleDOI
17 Jun 1990
TL;DR: A comparison of the predictive abilities of both the neural network and the discriminant analysis method for bankruptcy prediction shows that neural networks might be applicable to this problem.
Abstract: A neural network model is developed for prediction of bankruptcy, and it is tested using financial data from various companies. The same set of data is analyzed using a more traditional method of bankruptcy prediction, multivariate discriminant analysis. A comparison of the predictive abilities of both the neural network and the discriminant analysis method is presented. The results show that neural networks might be applicable to this problem

767 citations


Journal ArticleDOI
TL;DR: The theoretical bases behind the direct ECG data compression schemes are presented and classified into three categories: tolerance-comparison compression, DPCM, and entropy coding methods and a framework for evaluation and comparison of ECG compression schemes is presented.
Abstract: Electrocardiogram (ECG) compression techniques are compared, and a unified view of these techniques is established. ECG data compression schemes are presented in two major groups: direct data compression and transformation methods. The direct data compression techniques are ECG differential pulse code modulation (DPCM) and entropy coding, AZTEC, Turning-point, CORTES, Fan and SAPA algorithms, peak-picking, and cycle-to-cycle compression methods. The transformation methods include Fourier, Walsh, and Karhunen-Loeve transforms. The theoretical bases behind the direct ECG data compression schemes are presented and classified into three categories: tolerance-comparison compression, DPCM, and entropy coding methods. A framework for evaluation and comparison of ECG compression schemes is presented. >

690 citations


Journal ArticleDOI
01 Jun 1990-Ecology
TL;DR: In this article, the number of observed species, extrapolations of species-area curves, integration of the lognormal distribution, and nonparametric estimators have been proposed for estimating the species richness in a community.
Abstract: Numerous methods have been proposed for estimating the number of species, or species richness (SR) in a community. Most methods assume taxa are sampled as "individuals" (e.g., Fisher et al. 1943, Efron and Thisted 1976, Slocomb and Dickson 1978). This may be approporiate for animals, which occur as discrete individuals, but it is inappropriate for plants, which often exhibit clonal reproduction. Several methods for estimating SR are quadrat-based rather than individual-based, and are thus appropriate for plants. With these methods, abundance or presence of each species is recorded in randomly located quadrats. Estimators of SR fall into four categories: (1) number of observed species, (2) extrapolations of species-area curves, (3) integration of the lognormal distribution, and (4) nonparametric estimators. The performance of SR estimators has been assessed either by comparing the estimator to the measured SR at one or a few areas (Arrhenius 1923, Kilburn 1966, Miller and Wiegert 1989), or by simulation (Slocomb and Dickson 1978, Heltshe and Forrester 1983, Smith and van Belle 1984). The problem with the former approach is that the sample size is insufficient to establish the validity of a method. The problem with the latter approach is that computer-generated patterns may not mimic real patterns. These problems can be ameliorated by intensively sampling real communities at numerous sites. With a number of estimated SR values to contrast with actual SR values, we can determine whether the estimator is biased (i.e., it consistently overestimates or underestimates) or accurate (it overestimates and underestimates equally), whether the procedure yields estimators that are close to actual values (regardless of the bias), and whether estimators are highly correlated with actual values. The main problem with studying numerous sites is that the sampling involved is time consuming, and must be per-

572 citations


Journal ArticleDOI
TL;DR: With the possible exception of improving lactose utilization by persons who are lactose maldigestors, no specific health or nutritional claims can yet be made for the lactic acid bacteria.
Abstract: There are several potential health or nutritional benefits possible from some species of lactic acid bacteria. Among these are: improved nutritional value of food, control of intestinal infections, improved digestion of lactose, control of some types of cancer, and control of serum cholesterol levels. Some potential benefits may result from growth and action of the bacteria during the manufacture of cultured foods. Some may result from growth and action of certain species of the lactic acid bacteria in the intestinal tract following ingestion of foods containing them. In selecting a culture to produce a specific benefit it is necessary to consider not only the wide variation among species of the lactic acid bacteria but also that among strains within a given species. With the possible exception of improving lactose utilization by persons who are lactose maldigestors, no specific health or nutritional claims can yet be made for the lactic acid bacteria.

489 citations


Journal ArticleDOI
TL;DR: Significant variations in bile tolerance and ability to assimilate cholesterol were observed among 12 cultures of Lactobacillus acidophilus of human origin and the most active cholesterol-assimilating cultures also varied in the ability to produce bacteriocins.

327 citations


Journal ArticleDOI
TL;DR: It is concluded that reduced luteal activity that accompanies negative energy balance may be associated with reduced concentrations of insulin-like growth factor-I in serum, energy balance, body condition, and ovarian activity during early lactation.

289 citations


Journal Article
TL;DR: In the pig, establishment of pregnancy begins about 11-12 days after the start of oestrus and oestrogen derived from the conceptus or from administration to cyclic gilts stimulates uterine secretion of calcium and specific polypeptides as discussed by the authors.
Abstract: In the pig, establishment of pregnancy begins about 11-12 days after the start of oestrus. The ability of pig conceptuses to synthesize and release oestrogens during this period, as well as the ability of exogenous oestrogens to induce pseudo-pregnancy when administered from Day 11-15 of the oestrous cycle, provide evidence for an involvement of oestrogen in the maternal recognition of pregnancy in the sow. Oestrogen derived from the conceptus or from administration to cyclic gilts stimulates uterine secretion of calcium and specific polypeptides on Day 11-12. The specific roles for the uterine secretory response to oestrogen in the maintenance of pregnancy are unknown. However, it has been proposed that oestrogen prevents luteolysis in the sow through reorientation of endometrial prostaglandin release, i.e. into the uterine lumen rather than into the uterine vasculature. Oestrogen may interact with prolactin and/or conceptus secretory proteins to shift the direction of prostaglandin movement. Although conceptus oestrogen synthesis triggers a number of uterine secretory events on Day 11, a second sustained phase of oestrogen stimulation from Day 14 to 18 appears to be necessary for luteal maintenance beyond Day 25. Pig conceptuses synthesize and release large amounts of oestrogens between Days 14 and 18 of pregnancy. Conceptus oestrogens are clearly involved with the establishment of pregnancy. However, the conceptus also secretes a number of biologically active substances such as catechol oestrogens, prostaglandins and polypeptides which could interact with oestrogen to prevent luteolysis. The roles of these factors in control of vascular permeability, blood flow, placental attachment and immunological protection certainly indicate that, in addition to oestrogens, other factors are involved in the establishment of pregnancy in pigs.

196 citations


Journal ArticleDOI
TL;DR: The high specificities of some venom phospholipases A2 for skeletal muscle cells suggest a specific binding to certain membrane receptors; however, an enzymatic action on membranes may also be involved.

190 citations


Journal ArticleDOI
TL;DR: In this paper, it has been shown that the solvable n-state chiral Potts model is related to a vertex model with N-state spins on vertical edges, two-state spin on horizontal edges.
Abstract: It has recently been shown that the solvable N-state chiral Potts model is related to a vertex model with N-state spins on vertical edges, two-state spins on horizontal edges. Here we generalize this to a “j-state by N-state” model and establish three sets of functional relations between the various transfer matrices. The significance of the “super-integrable” case of the chiral Potts model is discussed, and results reported for its finite-size corrections at criticality.

180 citations


Journal ArticleDOI
TL;DR: This article found that the link between multi-member plurality systems and women's representation is small and occurs only in some systems, and suggested that women may prefer to be candidates in multiracial systems, that their election is facilitated by greater turnover in multi-membership systems and that multimember systems give voters and party leaders an opportunity to exercise a sort of electoral affirmative action.
Abstract: Recent research has suggested a link between multi-member district plurality elections and greater representation of women. Those proposing such a link argue that women may prefer to be candidates in multi-member systems, that their election is facilitated by greater turnover in multi-member systems, and that multi-member systems give voters and party leaders an opportunity to exercise a sort of electoral affirmative action. These possibilities are tested using data on more than 13,000 candidates for office in British and U.S. subnational elections. In general, the link between multi-member plurality systems and women's representation is small and occurs only in some systems. The paper concludes with suggestions for future avenues of exploration of the link between political structure and women's electability.

151 citations




Journal ArticleDOI
TL;DR: Females, but not males, appear to use the tail as a status-signalling badge, or indicator of resource-holding potential, and females may assume an alternate social role once the tail is lost.

Journal ArticleDOI
TL;DR: To the knowledge, this is the first myotoxic phospholipase to be sequenced that lacks presynaptic neurotoxicity and appears to exist as a monomer, contains 122 amino acids, and fits with subgroup IIA of other sequenced phospholIPase A2 molecules.

Journal ArticleDOI
TL;DR: The specificity and sensitivity of PCR combined with its simplicity and speed suggests the potential of this technique for routine diagnosis of brucellosis.
Abstract: A highly sensitive and specific diagnostic test for Brucella based on polymerase chain reaction is under development in our laboratory. A commercially available PCR kit was used to create primers that allowed the amplification of a 635 bp fragment of a 43 kDa outer membrane protein gene from Brucella abortus strain 19. We successfully amplified the cloned gene present in the pMS64 plasmid and genomic Brucella S19 DNA. The amplified DNA was easily detected by agarose gel electrophoresis. Using both the pMS64 plasmid and Br. abortus S19 purified DNA as template each component of the PCR reaction was adjusted for the optimum amplification of the DNA sequence. Optimum specific amplification resulted when the primer annealing temperature was 60 degrees C. The gene fragment was amplifiable in 25 different Brucella species and strains. To test the specificity of the reaction, DNA extracted from 17 micro-organisms possibly associated with cattle were tested. No amplification was observed. The sensitivity of the reaction was determined with different concentrations of genomic Brucella strain 19 DNA. As little as 0.1 pg DNA (less than 100 brucella cells) could be detected. The specificity and sensitivity of PCR combined with its simplicity and speed suggests the potential of this technique for routine diagnosis of brucellosis.

Journal ArticleDOI
TL;DR: In this article, a reliability-based optimization model for water-distribution systems is developed, which is aimed at the following goals: (1) design of the pipe network including the number, location, and size of pumps and tanks; (2) designing of the pumping system using a reliabilitybased procedure considering both hydraulic failures of the entire network and mechanical failure of the pump system; and (3) determination of the optimal operation of the pumps.
Abstract: A reliability-based optimization model for water-distribution systems has been developed. The model is aimed at the following goals: (1) Design of the pipe network including the number, location, and size of pumps and tanks; (2) design of the pumping system using a reliability-based procedure considering both hydraulic failures of the entire network and mechanical failure of the pumping system; and (3) determination of the optimal operation of the pumps. The optimization problem is a large mixed-integer, nonlinear programming problem that is solved using a heuristic algorithm consisting of a master problem and a subproblem. The master problem is a pure 0–1 integer programming model, and the subproblem is a large nonlinear programming model solved in an optimal control framework. The conservation of flow and energy constraints are solved implicitly for each iteration of the nonlinear optimization procedure using a hydraulic simulation model, and the reliability constraints are also solved implicitly using a reliability model. The nonlinear programming problem is solved using a generalized reduced gradient code.

Journal Article
TL;DR: Transstadial transmission of granulocytic Ehrlichieae in dogs was attempted using ticks, Amblyomma americanum and Dermacentor variabilis, and evidence of transmission was not observed in control dogs or in those exposed to D Variabilis.
Abstract: Transstadial transmission of granulocytic Ehrlichieae in dogs was attempted using ticks, Amblyomma americanum and Dermacentor variabilis. Ticks were exposed by feeding as nymphs on acutely infected pups; adult ticks then fed to repletion on susceptible adult dogs that were monitored daily for signs of infection. Evidence of transmission was not observed in control dogs or in those exposed to D variabilis. In contrast, dogs exposed to A americanum developed serologic or clinical evidence of infection, but organisms were not seen in blood smears until corticosteroids were administered, causing recrudescence and accompanying parasitemia. At 12 days after subinoculation of blood obtained from donor adult dogs, before corticosteroids were administered, a febrile response, thrombocytopenia, and appearance of morulae in neutrophilic granulocytes were observed in 2 susceptible recipient dogs.

Journal ArticleDOI
TL;DR: The lack of similar significant pet presence (“ownership”) correlations supports the hypothesis that the children's relationships with their pets are more important than just the presence of one or more pets in their homes.
Abstract: Pets have been shown to influence human development, but whether the effect is due to the presence of a pet or to the person's relationship with a pet is uncertain. Mothers rated their young children's companion animal bond (relationship) and social competence on a parental questionnaire, and a researcher assessed the children's empathy, cooperation, and intelligence during home visits. Significant correlations were noted between the children's bonds with their companion animals and their scores on the social competency scales as well as their empathy scores. The lack of similar significant pet presence (“ownership”) correlations supports the hypothesis that the children's relationships with their pets are more important than just the presence of one or more pets in their homes.

Journal ArticleDOI
TL;DR: Sedimentation velocities are reported for suspensions of nearly hard PMMA (polymethylmethacrylate) spheres as a function of volume fraction as a result of changes in volume fraction at the freezing and melting points.
Abstract: Reduced sedimentation velocities are reported for suspensions of nearly hard PMMA (polymethylmethacrylate) spheres as a function of volume fraction. The absolute sedimentation velocities are sufficiently slow compared to crystal-growth rates so that phase separation is achieved during the sedimentation process. As a result the analytic behavior of the measured sedimentation velocity changes as a function of volume fraction at the freezing and melting points. This transition serves as a definitive marker for comparison with theoretical predictions of sedimentation velocities for hard-sphere liquids and crystals.

Journal ArticleDOI
TL;DR: The bacterium Alcaligenes eutrophus JMP134(pJP4) degrades trichloroethylene (TCE) by a chromosomal phenol-dependent pathway and by the plasmid-encoded 2,4-dichlorophenoxyacetic acid pathway, which exhibited different rates of removal and capacities for quantity of TCE removed.
Abstract: The bacterium Alcaligenes eutrophus JMP134(pJP4) degrades trichloroethylene (TCE) by a chromosomal phenol-dependent pathway and by the plasmid-encoded 2,4-dichlorophenoxyacetic acid pathway. The two pathways were independent and exhibited different rates of removal and capacities for quantity of TCE removed. The phenol-dependent pathway was more rapid (0.2 versus 0.06 nmol of TCE removed per min per mg of protein) and consumed all detectable TCE. The 2,4-dichlorophenoxyacetic acid-dependent pathway removed 40 to 60% of detectable TCE.

Journal ArticleDOI
TL;DR: In this paper, the authors present a simple but effective procedure for determining whether a reasonably large sample comes from a stable population against the alternative of a population with finite higher moments, using the fact that the stable population sample has moments of the fourth and sixth order whose magnitudes increase very rapidly as the sample size increases.
Abstract: We present a simple but effective procedure for determining whether a reasonably large sample comes from a stable population against the alternative that it comes from a population with finite higher moments. The procedure uses the fact that a stable population sample has moments of the fourth and sixth order whose magnitudes increase very rapidly as the sample size increases. This procedure shows convincingly that stock returns, when taken as a group, do not come from stable populations. Even for individual stocks, our results show that the stable-population-model null hypothesis can be rejected for more than 95% of the stocks.

Journal ArticleDOI
TL;DR: In this article, the complex structural relationship between the East Anatolian and Dead Sea fault zones is examined, mostly based on field observations in southeastern Turkey where the two fault zones are close together.

Journal ArticleDOI
TL;DR: Improvement in gnc may require an improvement in both post-anthesis N uptake and increased partitioning of that N to the grain, since nitrogen harvest index and other N-redistribution variables were not correlated with gnc.

Journal ArticleDOI
TL;DR: Chez la genisse et le bouvillon, on etudie l'efficacite de l'alimentation en comparant les effets de regimes alimentaires restrictifs ou non, de ble ou de mais, sous differentes methodes de stationnement.
Abstract: Chez la genisse et le bouvillon, on etudie l'efficacite de l'alimentation en comparant les effets de regimes alimentaires restrictifs ou non, de ble ou de mais, sous differentes methodes de stationnement; en mesurant le poids corporel, celui de la carcasse. On etudie les causes de l'augmentation de l'efficacite alimentaire lors d'une consommation alimentaire limitee; digestibilite du repas et diminution des dechets alimentaires, activite de l'animal, taille des organes (besoins energetiques de maintenance)

Journal ArticleDOI
TL;DR: This paper examined the relationship between chronic work stressors, coping techniques, distress symptoms, and work performance for 91 organizational newcomers and found that, contrary to expectations, choice of coping techniques was not correlated with performance.
Abstract: This study examined the relationship between chronic work stressors, coping techniques, distress symptoms, and work performance for 91 organizational newcomers. Contrary to expectations, choice of ...

Journal ArticleDOI
TL;DR: A progressive alignment strategy, aligning first those sequences known to be similar, and then aligning the resulting groups of sequences, was used to examine further the relatedness of the amino acid sequences of putative transport proteins of caulimoviruses, and the analysis of the number of insertions/deletions between present sequences and a hypothetical common ancestor suggest that the sequences of the caulimoviral proteins are less diverged from the ancestor.
Abstract: Department of Biochemistry, Oklahoma State University, Stillwater, Oklahoma 74078-0454, U.S.A. The nucleic acids of many plant viruses encode proteins with one or more of the following properties: an Mr of approximately 30000, localization in the cell wall of the infected plant and a demonstrated role in cell-to- cell transport of infection. A progressive alignment strategy, aligning first those sequences known to be similar, and then aligning the resulting groups of sequences, was used to examine further the relatedness of the amino acid sequences of putative transport proteins of caulimoviruses, of proteins similar to the putative transport protein of alfalfa mosaic virus (AIMV) and of those similar to the tobacco mosaic virus (TMV) 30K protein. The strategy first identified regions in which multiple dipeptides of one group were similar to those of another group. The regions of similarity were brought into alignment by the conser- vative introduction of gaps. The positions of the intro- duction of gaps were adjusted to optimize similarity. Statistical significances of the resulting alignments, determined both by comparison with shuffled amino acid sequences and with the sequence alignment off-set by 1 to 15 residues in each direction, suggest that the amino acid sequences of the three groups of viruses are distantly related. Nevertheless, significant relation- ships between members of the caulimoviral group of sequences and members of each of the AIMV-like and TMV-like groups were found. These relationships and the analysis of the number of insertions/deletions between present sequences and a hypothetical common ancestor suggest that the sequences of the caulimoviral proteins are less diverged from the ancestor than either the AIMV-like or TMV-like proteins. The alignment identified common regions of predicted secondary structure and regions of similar hydropathy, regions possibly crucial for proper functioning of the proteins.

Journal ArticleDOI
TL;DR: It is suggested that under high Ca, most Al in root tissue remains in a compartment such as the apoplast where it can be rapidly desorbed, and with low Ca, however, Al may permeate the plasmalemma more readily and be chelated only after prolonged exposure to citrate.

Journal Article
TL;DR: Pasteurella haemolytica LPS can alter bovine leukocyte functions, by dose-dependent inhibition or augmentation; it is directly toxic to bovines endothelium; it modifies cardiopulmonary hemodynamics; and it elevates circulatory prostanoids, serotonin, cAMP, and cGMP.
Abstract: Pasteurella haemolytica is represented by two biotypes (A and T), 15 serotypes, and numerous untypable strains. Specific biotypes and serotypes are associated with fibrinous pleuropneumonia (pneumonic pasteurellosis) in cattle, sheep, and goats, septicemic pasteurellosis in lambs, and mastitis in ewes. Four virulence factors have been associated with P. haemolytica: fimbriae, a polysaccharide capsule, endotoxin [lipopolysaccharide (LPS)], and leukotoxin (LKT). The interactions of these virulence factors with components of the pulmonary alveolus are discussed as a model for the pathogenesis of pasteurellosis. Fimbriae on P. haemolytica may enhance colonization of the upper respiratory tract. The capsule of P. haemolytica varies in composition among serotypes. It inhibits complement-mediated serum killing as well as phagocytosis and intracellular killing of P. haemolytica. The capsule enhances neutrophil directed migration and adhesion of P. haemolytica to alveolar epithelium. Pasteurella haemolytica LPS can alter bovine leukocyte functions, by dose-dependent inhibition or augmentation; it is directly toxic to bovine endothelium; it modifies cardiopulmonary hemodynamics; and it elevates circulatory prostanoids, serotonin, cAMP, and cGMP. Leukotoxin is produced by all known serotypes and many untypable strains. Leukotoxin is a poreforming cytolysin that affects ruminant leukocytes and platelets by altering function at low levels but causing lysis at high levels.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed that real exchange rate variability and the choice of exchange rate regime are jointly determined by estimating a simultaneous limited-dependent variable model, with data from a cross section of developing countries during the recent floating period.

Journal ArticleDOI
TL;DR: In this article, pyridylamino derivatives of maltooligosaccharides were separated by capillary zone electrophoresis in the pH range 3.0-4.5 using 0.1 M phosphate solutions as the running electrolyte.