Dimensional Reduction for Directed Branched Polymers

Dimensional reduction occurs when the critical behavior of one system can be related to that of another system in a lower dimension. We show that this occurs for directed branched polymers (DBP) by giving an exact relationship between DBP models in D+1 dimensions and repulsive gases at negative activity in D dimensions. This implies relations between exponents of the two models: $\gamma(D+1)=\alpha(D)$ (the exponent describing the singularity of the pressure), and $\nu_{\perp}(D+1)=\nu(D)$ (the correlation length exponent of the repulsive gas). It also leads to the relation $\theta(D+1)=1+\sigma(D)$, where $\sigma(D)$ is the Yang-Lee edge exponent. We derive exact expressions for the number of DBP of size N in two dimensions.Comment: 7 pages, 1 eps figure, ref 24 correcte

Phylogenetic evidence for the invasion of a commercialized European Phasmarhabditis hermaphrodita lineage into North America and New Zealand

Biological control (biocontrol) as a component of pest management strategies reduces reliance on synthetic chemicals, and seemingly offers a natural approach that minimizes environmental impact. However, introducing a new organism to new environments as a classical biocontrol agent can have broad and unanticipated biodiversity effects and conservation consequences. Nematodes are currently used in a variety of commercial biocontrol applications, including the use of Phasmarhabditis hermaphrodita as an agent targeting pest slug and snail species. This species was originally discovered in Germany, and is generally thought to have European origins. P. hermaphrodita is sold under the trade name Nemaslug®, and is available only in European markets. However, this nematode species was discovered in New Zealand and the western United States, though its specific origins remained unclear. In this study, we analyzed 45 nematode strains representing eight different Phasmarhabditis species, collected from nine countries around the world. A segment of nematode mitochondrial DNA (mtDNA) was sequenced and subjected to phylogenetic analyses. Our mtDNA phylogenies were overall consistent with previous analyses based on nuclear ribosomal RNA (rRNA) loci. The recently discovered P. hermaphrodita strains in New Zealand and the United States had mtDNA haplotypes nearly identical to that of Nemaslug®, and these were placed together in an intraspecific monophyletic clade with high support in maximum likelihood and Bayesian analyses. We also examined bacteria that co-cultured with the nematode strains isolated in Oregon, USA, by analyzing 16S rRNA sequences. Eight different bacterial genera were found to associate with these nematodes, though Moraxella osloensis, the bacteria species used in the Nemaslug® formulation, was not detected. This study provided evidence that nematodes deriving from the Nemaslug® biocontrol product have invaded countries where its use is prohibited by regulatory agencies and not commercially available

Multiple-criteria decision support system in highway infrastructure management

Highway infrastructure represents a significant part of the public assets, and through its lifetime, is exposed to various deterioration processes leading to the depreciation of its value. It is therefore of vital importance to manage these assets aiming to reduce the loss of their value with time to a minimum. A typical task of road managers is making decisions related to maintenance, repair and rehabilitation based on data regarding the existing condition, risk of its use, life cycle costs and age. Road infrastructure is complex, and therefore the optimal choice of planned interventions is a delicate task often left to the road managers’ subjective judgment. The main goal of research work presented in the paper is the development of a multiple criteria decision support system to determine the priority ranking of asset rehabilitation projects. Results are presented for a selected case study that consists of 27 overpasses for a highway section. The data on the condition of crossovers obtained by regular inspection along their contribution to a structured database are essential. The selection of the set of asset rehabilitation projects is carried out by using the developed decision support system that includes the budget constraint option. The selected set of asset maintenance/rehabilitation projects meets best the pre-defined combination of several criteria and therefore yields the maximized overall benefit. The results showing the selection criteria employed in the decision process and relative importance are crucial in obtaining the targeted goals. The selected criteria should therefore reflect the needs of the users and the actual conditions related to the assets

IMMUNOHISTOMORPHOMETRIC FEATURES OF ACTH CELLS IN JUVENILE RATS AFTER TREATMENT WITH ESTRADIOL OR HUMAN CHORIONIC GONADOTROPIN IMUNOHISTOMORFOMETRIJSKE ODLIKE ACTH ]ELIJA U JUVENILNIH PACOVA NAKON TRETMANA ESTRADIOLOM ILI HUMANIM HORIONSKIM GONADOTROPINOM

Summary: Estradiol and human chorionic gonadotropin (hCG) are very important in controlling the secretory activity of hormone producing cells in the female rat pituitary glands. The aim of the present study was to examine the morphometric parameters of immunohistochemically la be led ACTH cells in juvenile (16th day) female rat pituitaries after treatment with five doses of estradiol dipropionate (EDP) and two doses of hCG during the neonatal period of life. The controls were treated on the same schedule with an equivalent volume of vehicle. All animals were sacrificed 24 h after the last treatment. ACTH-producing cells were stu died using the peroxidase-antiperoxidase immunohistochemical procedure. The absolute and relative pituitary weights were increased (p<0.05) only in the EDP treated group by 120.0% and by 121.1% respectively, in comparison with the controls. In this group, the volume of ACTH cells, volume of their nuclei and vo lume density were significantly decreased (p<0.05) by 6.4%, 33.3% and 46.2% respectively, compared to the corresponding controls. After treatment with hCG, there were no significant (p>0.05) changes neither in the volume of ACTH cells nor in the volume of their nuclei, in comparison with the controls. On the basis of the results obtained in our study, it can be concluded that EDP, injected into female rats during the neonatal period of life, has an inhibitory effect on the immunohistomorphometric parameters of ACTH cells, but such an effect is not clearly expressed after treatment with hCG. Keywords: ACTH cells, EDP, hCG, female rats Kratak sadr`aj: Estradiol i humani horionski gonadotropin (hCG) veoma su va`ni u kontroli sekretorne aktivnosti }elija hipofize koje proizvode hormone. Cilj ove studije je bio ispitati morfometrijske parametre imunohistohemijski obele`enih ACTH }elija hipofize `enki pacova, u juvenilnom periodu (16. dan), nakon tretmana sa pet doza estradiol-dipropionata (EDP) ili dve doze humanog horionskog gonadotropina (hCG). Kontrole su bile tretirane na istovetan na~in sa odgovaraju}om koli~inom rastvara~a. Svè ivotinje su bile `rtvovane 24 h nakon poslednjeg tretmana. ACTH }elije su bile imunohistohemijski obele`ene metodom peroksidaza-antiperoksidaza (PAP). Dobijeni rezultati ukazuju na zna~ajno pove}anje (p<0,05) apsolutne i relativne mase hipofize za 120% i 121,1% kod `enki tretiranih sa EDP u odnosu na kontrolu. U ovoj grupi `enki pacova volumen ACTH }elija i njihovih jedara, kao i njihova volumenska gustina su bili zna~ajno smanjeni (p<0,05) za 6,4%, 33,3% i 46,2% u pore|enju sa kontrolom. Nakon tretmana hCG-om, volumen ACTH }elija, kao i volumen njihovih jedara, nisu bili zna~ajno (p>0,05) promenjeni u odnosu na kontrolu. Na osnovu dobijenih rezultata moemo zaklju~iti da EDP, injeciran `enkama pacova tokom neonatalnog perioda `ivota, ima inhibitorni efekat na imuno histomorfometrijske parametre ACTH }e lija, {to nije tako jasno izra`eno nakon tretmana hCG-om. Klju~ne re~i: ACTH }elije, EDP, hCG, `enke pacova J Med Biochem 2012; 3