Finding perfect polynomials mod 2

A number is said to be “perfect” if it equals the sum of its proper divisors. For example 6 is “perfect” because 6 = 1 + 2 + 3. On the other hand, a polynomial with integer coefficients modulo 2 is said to be “perfect” if the sum of its divisors equals the polynomial itself. In this presentation, we will highlight work that has been done to identify and classify all “perfect” polynomials

The Effect of Ventilation on the Accuracy of Pulmonary Artery and Wedge Pressure Measurements

journal articleBiomedical Informatic

A Note on Using Eigenvalues in Dimensionality Assessment

The dimensionality of a set of items is important for scale development. In practice, tools that make use of eigenvalues are often used to assess dimensionality. Parallel analysis is featured here as it is becoming an increasingly popular method for assessing the number of dimensions, and computational tools have recently been made available which will likely increase its use by practitioners. The current paper argues that methods that use eigenvalues to ascertain the number of factors may perform poorly under certain conditions, particularly for increasing levels of variable complexity and/or inter-factor correlations in the latent structure. A simulation study and an example are offered to substantiate this assertion. Accessed 2,400 times on https://pareonline.net from September 06, 2017 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Molekularna serotipizacija sojeva bakterije Salmonella izoliranih iz pilećeg mesa za prodaju, na temelju in silico višestrukog PCR-a, određivanja ESBL-a i gena kolistin rezistencije mcr-1 do -5

Salmonella spp. are zoonotic pathogenic agents that cause important infections in humans and animals. They are the most common foodborne pathogens after Campylobacter spp. worldwide. The aim of this study was to determine the phenotypic and genotypic extended-spectrum β-lactamase (ESBL) and colistin resistance of 67 Salmonella spp. isolated from retail chicken meats between May and December 2016, and stored in the culture collection of Ataturk University, Faculty of Veterinary Medicine, Department of Microbiology. The isolates were serotyped using multiplex polymerase chain reaction (mPCR). The serovar distribution of strains was 74.6% S. Infantis, 16.4% S. Enteritidis, 3.0% S. Arizonae, 3.0% S. Dublin, 1.5% S. Gallinarum and 1.5% S. Indica. Of the 67 strains, 20 (29.9%) were ESBL- positive. The main types of β-lactamase identified were blaCTX-M-1, blaCTX-M-8-25, blaSHV and blaTEM. Four isolates were found to be phenotypically colistin-resistant. These isolates did not carry mobilised colistin resistance (mcr) genes 1 to 5. In this study, both genotypically ESBL-producing and phenotypically colistin-resistant Salmonella strains were found. We revealed that ESBL-producing Salmonella strains have dramatically increased over the years, especially when compared with previously reported chicken meat Salmonella strains in Turkey. The increase in Salmonella strains, particularly ESBL producers and the colistin resistant, is of great concern for selected antimicrobial therapy in human infections. Hence, epidemiological information and monitoring systems are extremely important in controlling Salmonella infections in public health services.Salmonella spp. zoonotski su patogeni koji uzrokuju infekcije u ljudi i životinja. Na globalnoj su razini najčešći patogeni koji se prenose hranom poslije bakterija Campylobacter spp. Cilj ovog istraživanja bio je fenotipski i genotipski odrediti β-laktamaze proširenog spektra (ESBL) i otpornost na kolistin 67 sojeva bakterija Salmonella spp. izoliranih iz pilećeg mesa za prodaju od svibnja do prosinca 2016. i pohranjenih u kulturama na Odsjeku za mikrobiologiju Fakulteta veterinarske medicine na Sveučilištu Ataturk. Izolati su serotipizirani primjenom višestruke lančane reakcije polimerazom (mPCR). Distribucija serovara bila je: 74,6 % za S. Infantis, 16,4 % za S. Enteritidis, 3,0 % za S. Arizonae, 3,0 % za S. Dublin, 1,5 % za S. Gallinarum i 1,5 % za S. Indica. Od 67 sojeva njih je 20 (29,9 %) bilo pozitivno na ESBL. Glavni identificirani tipovi β-laktamaza bili su: blaCTX-M-1, blaCTX-M-8-25, blaSHV i blaTEM. Četiri izolata bila su fenotipski otporna na kolistin. Ovi izolati nisu sadržavali aktivne gene rezistencije na kolistin (mcr) 1 do 5. U ovom su istraživanju nađeni i sojevi salmonele koji su genotipski proizvodili ESBL i sojevi fenotipski otporni na kolistin. Sojevi salmonele koji proizvode ESBL s godinama su se znatno povećali, posebno u usporedbi s prethodnim izvješćima o sojevima salmonele u mesu pilića u Turskoj. Porast sojeva salmonele, osobito onih koji proizvode ESBL i onih koji su otporni na kolistin, zabrinjava zbog antimikrobnog liječenja infekcija u ljudi. Zbog toga su u kontroli infekcija salmonelama u javnome zdravstvu iznimno važni epidemiološki podaci i sustavi praćenja

Persuasive technology for overcoming food cravings and improving snack choices

This research is partially supported by EPSRC Grant EP/G004560

Morphometrische Analyse der retinalen Ganglienzellen in der menschlichen Netzhaut

Ziel dieser Studie war es, mit neuroanatomischen Verfahren der Fluoreszenzfärbung retinale Ganglienzellen retrograd anzufärben, um sie zu beschreiben und zu klassifizieren. Dies ist wichtig, weil GZ bei verschiedenen Erkrankungen mit einer Degeneration reagieren. Es wurden 1-2 Tage post mortem entnommene Retinae nach Anfärbung mit DiI für mehrere Monate bei Raumtemperatur aufbewahrt. Einzelne „komplett“ angefärbte GZ wurden fluoreszenzmikroskopisch aufgenommen. Eine Klassifizierung der GZ erfolgte aufgrund ihrer: Morphologie, Größe, Dendritenposition und -anzahl sowie Lokalisation. Die RGZ zeigten eine aufschlussreiche morphologische Vielfältigkeit. Die Midgetzellen und die Parasolzellen konnten u.a. identifiziert, unterklassifiziert und morphometrisch ausgewertet werden. Hiernach wurde festgestellt, dass diese Technik der Fluoreszenzfärbung allein nicht geeignet ist, aussagekräftige Rückschlüsse über degenerierte GZ infolge bestimmter Erkrankungen zu machen

Growth, feedlot performance and carcass characteristics of Karakas and crossbred lambs (F1) (Ile de France x Akkaraman (G1) x Karakas) under rural farm conditions in Turkey

In this study the possibilities of using the Ile de France x Akkaraman (G1) genotype (IDFAG1) in improving the growth performance and carcass characteristics of fat-tailed Karakas sheep raised in rural farm conditions in the Van Region of Eastern Anatolia, Turkey, were investigated. The aim was to obtain some preliminary results for future studies which will be designed to develop a genotype which has the ability to adapt to the region's conditions, has a high yield and quality meat, grows fast, has a high feed conversion ability and a thin fat tail. Growth and feedlot performances and carcass characteristics of Karakas (KAR) and crossbred (IDFAK) lambs obtained from the mating of IDFAG1 rams with Karakas ewes were evaluated. A total of 97 KAR and IDFAK lambs reared under farm conditions was evaluated for growth characteristics. For the evaluation of feedlot performance and carcass characteristics, 10 KAR and seven IDFAK single-born male lambs weaned at two months of age were subjected to a finishing diet for 70 days and slaughtered. Least squares means of the weights of KAR and IDFAK lambs at birth and at six months were 3.2 ± 0.08 and 3.5 ± 0.08 kg and 29.6 ± 1.24 and 30.2 ± 1.41 kg, respectively. The means of untailed cold carcass weight and untailed dressing percentage of KAR and IDFAK lambs were 13.2 ± 0.39 and 14.3 ± 1.10 kg and 39.7 ± 0.42 and 44.3 ± 1.10%, respectively. Although feed efficiency and many carcass characteristics did not differ between groups, the carcasses of the IDFAK lambs contained a higher percentage of intramuscular fat that is desirable for consumers in Eastern Anatolia. Encouraging results have been obtained to suggest that IDFAG1 rams could be used to improve the productivity of Karakas sheep. Nevertheless, more detailed and larger scale experiments are needed to confirm the results on growth and carcass characteristics of crossbred lambs under different farm conditions. South African Journal of Animal Science Vol. 34(4) 2004: 223- 23

Rapid Microwave Polymerization of Porous Nanocomposites with Piezoresistive Sensing Function

In this paper, polydimethylsiloxane (PDMS) and multi-walled carbon nanotube (MWCNT) nanocomposites with piezoresistive sensing function were fabricated using microwave irradiation. The effects of precuring time on the mechanical and electrical properties of nanocomposites were investigated. The increased viscosity and possible nanofiller re-agglomeration during the precuring process caused decreased microwave absorption, resulting in extended curing times, and decreased porosity and electrical conductivity in the cured nanocomposites. The porosity generated during the microwave-curing process was investigated with a scanning electron microscope (SEM) and density measurements. Increased loadings of MWCNTs resulted in shortened curing times and an increased number of small well-dispersed closed-cell pores. The mechanical properties of the synthesized nanocomposites including stress–strain behaviors and Young’s Modulus were examined. Experimental results demonstrated that the synthesized nanocomposites with 2.5 wt. % MWCNTs achieved the highest piezoresistive sensitivity with an average gauge factor of 7.9 at 10% applied strain. The piezoresistive responses of these nanocomposites were characterized under compressive loads at various maximum strains, loading rates, and under viscoelastic stress relaxation conditions. The 2.5 wt. % nanocomposite was successfully used in an application as a skin-attachable compression sensor for human motion detection including squeezing a golf ball.This research received no external funding and The APC was funded by University Libraries Open Access fund. Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye

Modeling and stress analysis of wire ropes with parametric equations

Tel halat geometrisi imalat tarzından dolayı karmaşık bir yapıdadır. Halatın temel öğelerinden birisi halatın özünü oluşturan Bağımsız Tel Halat Çekirdeği (BTHÇ)’dir. BTHÇ ise ortasında yedi telden oluşan basit düz bir demet ve onu çevreleyen altı adet helisel sarılmış demetten oluşmaktadır. BTHÇ’nin merkez demeti ile dış demetinde yer alan helisel tellerin geometrileri arasında önemli bir fark vardır. Merkez demetin dış telleri tek helisel yapıya sahip iken, dış demeti oluşturan dış teller çift helisel yapıdadır. Bu sebepten ötürü dış demete ait dış çift helisel tellerin modellenmesi özel yöntemlerin kullanılmasını zorunlu kılmaktadır. Bu makalenin amacı, BTHÇ ile tel halatların modellenmesi için yeni bir tekniğin tanıtılması ve bu teknik ile elde edilecek sonuçların literatürde mevcut bulunan sonuçlarla karşılaştırılmasıdır. Öncelikle BTHÇ’nin merkezinde bulunan basit düz tel demetinin modeli oluşturularak modelin doğruluğu kanıtlanmıştır. Ardından BTHÇ’nin dış demetindeki dış tellerin çift helisel geometrisi incelenerek modellenme tekniği üzerinde durulmuştur. Farklı sarım teknikleri ile modellenmesi yapılan BTHÇ’lerin modelleri anlatılmıştır. BTHÇ’nin sonlu elemanlar kullanılarak analizleri sonucunda tel bazında elde edilen sonuçların analitik sonuçlarla mukayesesi yapılmıştır. En son olarak BTHÇ’nin öz olarak kullanıldığı Seale tipi tel halatların modellenmesi ve analizi yapılmıştır. Elde edilen sonuçlar literatürde bulunan analitik ve test sonuçlarıyla karşılaştırılmış ve iyi uyum sağladıkları görülmüştür. Sonuç olarak tanıtılan yeni modelleme tekniği kullanılarak kolay ve daha efektif bir biçimde sayısal analiz yapma olanağı sağlanmıştır. Aynı zamanda uygulanan yöntem daha basit ve daha pratiktir.  Anahtar Kelimeler: Tel demet, bağımsız tel halat çekirdeği, çift helisel geometri, Seale tipi halat modelleme.Loads and moments over an helical wire geometry is the fundamental starting point of the wire rope theory. The equilibrium equations are derived from the equilibrium of this wire and it has been presented by Love (1944) in his well-known treatise. Solution of the equilibrium equations under axial loading and pure bending is presented by Love (1944). Frictional and contact effects are not included in the theorethical investigations of the problem due to the complicated geometry. Without taking into account the frictional effects, nonlinear problem of wire rope theory is solved using linearization of the equilibrium equations. A simple wire strand is composed by a straight wire which is wrapped by six outer single helical wires. An independent wire rope core (IWRC) is composed by a simple straight strand as a core strand which is wrapped around by six outer helical strands. The outer wires of the core strand is helical shaped wires while the outer wire of the outer strands is double or nested helical wires. Double or nested helical wire geometry is not included in the analytical solution procedures during the development of the theory of wire ropes. Superposition theory is used for the solutions of the IWRC which takes into account core strand as a straight wire while the outer strands as a single helical wire. IWRCs are widely used as a core for more complicated wire ropes at present. Most of the well known structures are Seale and Warrington IWRC. IWRCs are preferred when the wire rope is run under large lateral compressive loads and additional axial loading capacity is required (Velinsky, 1989). During the literature survey, the first analytical analysis are done by Hruska (1951, 1952, 1953). Hruska did not take into account the frictional effects due to contacts while solving the equilibrium equations given by Love (1944). Only geometrical aspects, axial loading and pure bending are discussed during the early studies. Since then Costello (1990), and later, Utting and Jones (1987) have followed a more fundamental approach. They treat each wire of wire rope as a helically curved rod but make differing assumptions relative to the rope geometry or the interwire contacts. The different theories produce results, which remain close to the experimental values presented by Utting and Jones (1987), but the question of the actual relative displacements and forces within a rope is nevertheless still open. Early studies of the wire ropes under axial loading condition obtained by using finite element analysis are given by Jiang and Henshall (1999). Then this study is extended to three layered strand by Jiang et.al. (1999,2000). These analysis are based on a simple sector of 1/12 or 1/6 of the wire rope cross-section, an arc length or a percentage of the pitch length is taken into account generally. Meanwhile during the literature survey, analytical models conducted for IWRC have not mentioned double helical wire geometry until 2004. Most of the analitical analysis rely on homogenization process except theoretical studies of Elata et.al. (2004), Usabiaga and Pagalday (2008). In this article, wire rope geometry is modelled in a more realistic manner taking into account the double or nested helical geometry of the outer wires of the outer strands for IWRC. To accomplish this, a code is generated named Wire Rope Skeleton (WRS) which creates the centerline of the specified wire in a strand, IWRC or Seale IWRC. Proposed modeling scheme considers each wire with its real solid behaviour. Thus analysis over the wire rope with proposed structure gives more realistic results. To model long wire rope models in 3-D is a cumbersome issue due to the irregularities encountered on the surface of the wires while meshing. The proposed modeling scheme solves the meshing problems of long wire ropes. Also the interactions between wires are defined by contact definitions and friction is taken into account. Realistic material properties are defined and analytical results, test results available in the literature and the finite element analysis results are compared simultaneously. It has been concluded that the proposed modeling procedure works for a wire strand and its development to IWRC and Seale IWRC also gives reasonable results. This analysis technique gives more information about the interwire contacts. As this face this modeling scheme and analysis methodology gives oppurtunity for the future analysis. Keywords: Wire strand, independent wire rope core, double helical geometry, Seale type rope modeling.