A robust quadrilateral membrane finite element with drilling degrees of freedom

A quadrilateral membrane finite element with drilling degrees of freedom is derived from variational principles employing an independent rotation field. Both displacement based and mixed approaches are investigated. The element exhibits excellent accuracy characteristics. When combined with a plate bending element, the element provides an efficient tool for linear analysis of shells.     

Staphylococcus aureus leucocidin, a virulence factor in bovine mastitis

The involvement of Staphylococcus aureus exosecretions in bovine udder infection (Younis et al. 2003) suggests that four different monomer protein bands appearing between 36 and 31 kDa, are associated with the severity of the cow's infection response. Three out of these four bands have been identified by means of protein sequencing. Band B, with a MW of 35 kDa was identified as Panton-Valentaine leucocidin LukF'-PV chain- Staph. aureus; band C, with a MW of 32 kDa was identified as leucocidin chain LukM precursor- Staph. aureus; and band D was found to be similar, but not identical, to phosphatidylinositol-specific phospholipase-C-X. Bands B and C were purified by gel filtration using FPLC. The ability of these proteins to induce udder inflammation in vivo, and proliferation response in vitro and cytokine secretion were tested for both the crude exosecretions and purified bands. Three cows were inoculated intracisternally, with three quarters receiving either 0.007-0.008 mg (as total proteins) of Staph. aureus FR2449/1 bacterial exosecretion, pooled fraction 39-41 (bands B and C), or culture broth medium. The fourth quarter was left free as a control. Quarters that received fraction 39-41 of Staph. aureus FR2449/1, exhibited induced inflammation, which was indicated by increased somatic cell count and enhanced NAGase activity that was significantly higher than that of the original Staph. aureus FR2449/1 bacterial exosecretion. Proliferation tests of bovine blood lymphocytes in vitro showed that the pooled fraction 39-41 stimulated bovine proliferation of mononuclear cells much more than the original Staph. aureus FR2449/1 bacterial exosecretion. Secretion of TNF-alpha, IL-1beta, IL-6 and IL-8 was in accordance with the contents of LukF'-PV and LukM precursor in the exosecretions. The results suggest that LukM/ LukF' induce inflammation into the udder by a mechanism similar to that of LPS or by a unique mechanism(s) which requires further investigation.     

Fingerprint classification: a review

Biometrics is the automatic identification of an individual that is based on physiological or behavioural characteristics. Due to its security-related applications and the current world political climate, biometrics is currently the subject of intense research by both private and academic institutions. Fingerprints are emerging as the most common and trusted biometric for personal identification. The main objective of this paper is to review the extensive research that has been done on fingerprint classification over the last four decades. In particular, it discusses the fingerprint features that are useful for distinguishing fingerprint classes and reviews the methods of classification that have been applied to the problem. Finally, it presents empirical results from the state of the art fingerprint classification systems that have been tested using the NIST Special Database 4.     

Dynamic analysis of a multibody open-chain system

The free plane motion of a compound pendulum is studied using the Lagrange equations of motion. The specific compound pendulum consists of a main plane disk from which are suspended two chains, each of which is composed of m and n rigid plane disks, respectively. A nonlinear system of m + n + 1 ordinary differential equations (ODEs) with respect to the properly selected generalized coordinates, is obtained. For small-amplitude swing the above system becomes a linear differential system. The eigenvalues and eigenvectors constitute the eigenfrequencies and the modeshapes, respectively, of the free swing of the considered compound pendulum. Also, relations are extracted which ensure a unique swing with no relative rotation between any two disks. Finally, several numerical results are given.     

Deduction in non-Horn databases

The class of non-Horn, function-free databases is investigated and several aspects of the problem of using theorem proving techniques for such databases are considered. This includes exploring the treatment of negative information and extending the existing method, suggested by Minker, to accept non-unit negative clauses. It is shown that the algorithms based on the existing methods for the treatment of negative information can be highly inefficient. An alternative approach is suggested and a simpler algorithm based on it is given. The problems associated with query answering in non-Horn databases are addressed and compared with those for the Horn case. It is shown that the query evaluation process can be computationaly difficult in the general case. Conditions under which the process is simplified are discussed. The topic of non-Horn general laws is considered and some guidelines are suggested to divide such laws into derivation rules and integrity constraints. The effect of such a division on the query evaluation process is discussed.     

Serum erythrocyte and leukocyte adenosine deaminase activities in patients with vivax malaria in Turkey

Adenosine deaminase (ADA) activities in serum samples, erythrocytes, leukocytes and plasma hemoglobin concentrations were investigated in 50 patients with vivax malaria and compared with control group. ADA activity was determined by Bertholet reaction. Student's t-test and correlation analyses methods were used for statistical analyses. Serum ADA activity in patients with vivax malaria 49.20 +/- 29.02 IU/I, in control 21.15 +/- 8.04 IU/I (p = 0.005), erythrocyte ADA activity in patients 2.91 +/- 1.23 U/gr Hb, in control 1.65 +/- 0.59 U/gr (p = 0.001), leukocyte specific ADA activity in patients 26.23 +/- 20.21 U/mg protein, in control 25.84 +/- 9.19 U/gr Hb were determined (P > 0.05). Plasma hemoglobin concentration in patients 29.25 +/- 28.10 ml/dl, in control 9.80 +/- 13.14 mg/dl were also determined. There is no significant correlation among mentioned parameters. Erythrocyte purine salvage pathway is accelerated by Plasmodium to provide preformed purine source which can not be synthesized by Plasmodium to provide preformed purine source which can correlation between plasma hemoglobin concentration and serum ADA activity suggests that increased serum ADA activity may develop secondarily to the disease independently from the hemolyses. No higher ADA activity level than expected value of leukocytes may reflect immunosuppression of leukocytes.     

Effects of Vegetation Cover on the Radar Sensitivity to Soil Moisture

Measurements of the backscattering coefficient ?°, made for bare and vegetation-covered fields, are used in conjunction with a simple backscattering model to evaluate the effects of vegetation cover on the estimation accuracy of soil moisture when derived from radar observations. The results indicate that for soil moisture values below 50 percent of field capacity, the backscatter contribution of the vegetation cover limits the radar's ability to predict soil moisture with an acceptable degree of accuracy. However, for moisture values in the range between 50 and 150 percent of field capacity, the measured ?° is dominated by the soil contribution and the effects of vegetation cover become secondary in importance. It is estimated that in this upper soil moisture range, which is the primary range of interest in hydrology and agriculture, a radar soil moisture prediction algorithm would predict soil moisture with an error of less than ±15 percent of field capacity in 90 percent of the cases.     

COMPUTING PERFECT AND STABLE MODELS USING ORDERED MODEL TREES

Ordered model trees were introduced as a normal form for disjunctive deductive databases. They were also used to facilitate the computation of minimal models for disjunctive theories by exploiting the order imposed on the Herbrand base of the theory. In this work we show how the order on the Herbrand base can be used to compute perfect models of a disjunctive stratified finite theory. We are able to compute the stable models of a general finite theory by combining the order on the elements of the Herbrand base with previous results that had shown that the stable models of a theory T can be computed as the perfect models of a corresponding disjunctive theory ɛ T resulting from applying the so called evidential transformation to T. While other methods consider many models that are rejected at the end, the use of atom ordering allows us to guarantee that every model generated belongs to the class of models being computed. As for negation-free databases, the ordered tree serves as the canonical representation of the database.     

Linear estimator stabilization of nonlinear sampled-data systems

It has been shown that the state of a linear system can be constructed from observations of its inputs and outputs. The observer which performs the construction is itself a linear system with time constants which may be chosen by the designer. This linear asymptotic estimator has been used previously to stabilize certain types of contimuous nonlinear systems. In this paper, a linear sampled-data estimator is developed. This estimator is used first to stabilize a linear sampled-data system and then it is used to stabilize a class of nonlinear sampled-data systems by the choice of the estimator's time constants and the feedback gain. Typical example applications are analyzed to illustrate the theoretical investigations.