Structure in a Loitering Universe

We study the formation of structure for a universe that undergoes a recent loitering phase. We compare the nonlinear mass distribution to that in a standard, matter dominated cosmology. The statistical aspects of the clustered matter are found to be robust to changes in the expansion law, an exception being that the peculiar velocities are lower by a factor of $\sim 3$ in the loitering model. Further, in the loitering scenario, nonlinear growth of perturbation occurs more recently ($z\sim 3-5$) than in the matter dominated case. Differences in the high redshift appearances of the two models will result but observable consequences depend critically on the chosen form, onset and duration of the loitering phase.Comment: 8 pages, (uses revtex.sty), 5 figures not included, available on request, UM AC 92-

Effects of Feed Additives and Mixed Eimeria Species Infection on Intestinal Microbial Ecology of Broilers

Evaluation of digestive microbial ecology is necessary to understand effects of growth-promoting feed. In the current study, the dynamics of intestinal microbial communities (MC) were examined in broilers fed diets supplemented with a combination of antibiotic (bacitracin methylene disalicylate) and ionophore (Coban 60), and diets containing 1 of 2 essential oil (EO) blends, Crina Poultry (CP) and Crina Alternate (CA). Five treatments were analyzed: 1) unmedicated uninfected control; 2) unmedicated infected control; 3) feed additives monensin (bacitracin methylene disalicylate) + monensin (Coban 60; AI); 4) EO blend CP; and 5) EO blend CA. Additives were mixed into a basal feed mixture, and EO were adjusted to 100 ppm. Chicks were infected by oral gavage at 19 d of age with Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Duodenal, ileal, and cecal samples were taken from 12 birds per treatment just before and 7 d after challenge; 2 samples each were pooled to give a final number of 6 samples total; and all pooled samples were frozen until used for DNA extraction. Denaturing gradient gel electrophoresis was used to examine PCR-amplified fragments of the bacterial 16S ribosomal DNA variable region. Results are presented as percentages of similarity coefficients (SC). Dendrograms of PCR amplicon or band patterns indicated MC differences due to intestinal location, feed additives, and cocci challenge. Essential oil blends CP and CA affected MC in all gut sections. Each EO had different effects over MC, and they differed in most instances from the AI group. The cocci challenge caused drastic MC population shifts in duodenal, ileal, and cecal sections (36.7, 55.4, and 36.2% SC, respectively). Diets supplemented with CP supported higher SC between pre- and postchallenge MC (89.9, 83.3, and 76.4%) than AI (81.8., 57.4, and 60.0%). We concluded that mixed coccidia challenge caused drastic shifts in MC. These EO blends modulated MC better than AI, avoiding drastic shifts after a mixed challenge

Intestinal Microbial Ecology of Broilers Vaccinated and Challenged With Mixed Eimeria Species, and Supplemented with Essential Oil Blends

Intestinal microbiota is an important component in the development of defense mechanisms in the gut mucosa. This project determined the dynamics of intestinal microbial communities (MC) of broilers vaccinated at first day of age with live oocysts of Eimeria species and fed diets supplemented with 2 specific essential oil (EO) blends, Crina Poultry (CP) and Crina Alternate (CA). Five treatments were analyzed: 1) unmedicated-uninfected (UU) control; 2) unmedicated-infected (UI) control; 3) vaccinated with Advent cocci-vaccine and without feed additive (COV) supplements; 4) vaccinated with Advent and supplemented with CP; and 5) vaccinated with Advent and supplemented with CA. The EO blends were added at 100 ppm to the same basal diets. Chicks were gavage-infected at 19 d of age with Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Duodenal, ileal, and cecal samples were taken from 12 birds per treatment just before the infection and 7 d after the challenge, pooled in 6 samples, and frozen. Denaturing gradient gel electrophoresis was used to examine PCR-amplified fragments of the bacterial 16S ribosomal DNA variable region. Results are presented as percentages of similarity coefficients (SC). Dendrograms of amplicon patterns indicated MC differences due to intestinal location, feed additives, and cocci infection. The EO blends CP and CA did affect MC in all gut sections. The cocci-infection caused drastic MC population shifts in duodenal, ileal, and cecal sections (36.7, 55.4, and 36.2% SC, respectively). The CP-supplemented birds had higher SC between pre- and postchallenge MC in duodenal and ileal (73.3, 81.8%) than COV (66.4, 66.5%). However, COV broilers had the smallest changes in cecal MC after infection (79.5% SC). We concluded that cocci-vaccination causes small changes in intestinal MC, but challenge causes drastic shifts. The EO blend supplementation modulates MC in cocci-vaccinated broilers, avoiding drastic shifts after a mixed coccidia infection. Correlations between MC dynamics and host responses are discussed

Neighbourhoods in Scottish New Towns

The hew Towns Act 1946, initiated an era of town construc- tion according to a national policy. In Scotland five New Towns are being built. Of these, East Kilbride is reaching the final stages, while Irvine's first immigrants settled in August 1969. The Towns, under the control of Development Corporations, have been planned so that the limitations of inter -war housing estates are avoided. In particular, emphasis has been laid on transport networks that facilitate communications, and on the establishment of self-contained communities. In the first New Towns construction of neighbourhood units was considered an appropriate method of overcoming anonymity in a town, and an aid to promoting the welfare of immigrants. Other kinds of residential units have been planned in the more recent towns. Problems of creating a self-contained, balanced neighbourhood are aggravated by an immature age structure and socio- economic imbalance.The study takes into account the physical and social structure of the residential units in East Kilbride, Glenrothes and Livingston; and reveals that in none of them have neighbourhoods come into existence through the continued interaction of residents throughout the area planned as a unit.The provision of facilities such as shops, schools, and clinics aids the self- containment of a unit, but not necessarily its cohesiveness which is related to the extent and frequency of the use, rather than the existence of facilities. Investigation of the patterns relatin;- to shopping, employment, churches and schools attended, recreation, and visiting habits, has shown that the effectiveness of neighbourhood boundaries is only partly a result of their physical character. Movement across a boundary is influenced primarily by the attraction of features on the other side. Furthermore, if facilities within the residential unit are not sufficiently attractive, the high level of mobility in the New Towns permitt residents to pursue activities beyond their own units.Cohesive qualities of residential units are related partly to the size of the unit, and to the proximity of the population's earlier homes which provide a strong attraction away from the unit. A sense of cohesion could be inculcated through participation in organisations whose membership is drawn from the residential unit, or whose activities are related directly to the unit, but these have proved of little consequence as few organisations cater specifically for people within one unit, and society membership within a unit is characteristic of only a small proportion of the New Town populations.Instead of residential units becoming cohesive entities most of them are comprised of a number of sub -regions related to the socio- economic structure, to the demographic characteristics, to the stage at which the area was built in the development of the unit, and to the influence exerted on a small area by a focal point either within or outwith the unit. Lack of a major focal point in a unit, a heterogeneous population and a good communications network for public and private transport permitting easy access to nearby centres, are not conducive to the establishment of a cohesive neighbourhood

Approaching finite-temperature phase diagrams of strongly correlated materials: a case study for V2O3

Examining phase stabilities and phase equilibria in strongly correlated materials asks for a next level in the many-body extensions to the local-density approximation (LDA) beyond mainly spectroscopic assessments. Here we put the charge-self-consistent LDA+dynamical mean-field theory (DMFT) methodology based on projected local orbitals for the LDA+DMFT interface and a tailored pseudopotential framework into action in order to address such thermodynamics of realistic strongly correlated systems. Namely a case study for the electronic phase diagram of the well-known prototype Mott-phenomena system V$_2$O$_3$ at higher temperatures is presented. We are able to describe the first-order metal-to-insulator transitions with negative pressure and temperature from the self-consistent computation of the correlated total energy in line with experimental findings.Comment: 12 pages, 15 figures, new data adde

Beyond Time Out and Table Time: Today's Applied Behavior Analysis for Students with Autism

Recent mandates related to the implementation of evidence-based practices for individuals with autism spectrum disorder (ASD) require that autism professionals both understand and are able to implement practices based on the science of applied behavior analysis (ABA). The use of the term “applied behavior analysis” and its related concepts continues to generate debate and confusion for practitioners and family members in the autism field. A general lack of understanding, or misunderstanding, of the science and practice of ABA is pervasive in the field and has contributed to an often contentious dialogue among stakeholders, as well as limited implementation in many public school settings. A review of the history of ABA and its application to individuals with ASD is provided, in addition to a discussion about practices that are/are not based on the science of ABA. Common myths related to ABA and ASD, as well as challenges practitioners face when implementing practices based on the science of ABA in public school settings are also described

Rapid Detection of Avian Eimeria Species Using Denaturing Gradient Gel Electrophoresis

A denaturing gradient gel electrophoresis (DGGE) assay was developed to rapidly discriminate species of avian Eimeria. Amplification by PCR of the small subunit ribosomal RNA gene (approximately 1,600 nucleotides) with Eimeria genus-specific primers followed by cloning and sequencing allowed us to carry out phylogenetic analyses and identify clone sequences to species level in most cases. Clones were subsequently used to amplify a smaller fragment (approximately 120 nucleotides) suitable for DGGE. The fragments were separated on denaturing gradient gel and bands with unique migration distances were mixed to obtain an identification ladder. The identification ladder and PCR products obtained from DNA extracted from fecal samples from several poultry farms were compared. Applying the DGGE method in this study allowed a rapid differentiation of Eimeria species present in fecal samples collected from poultry farms

Loss of the DNA methyltransferase MET1 Induces H3K9 hypermethylation at PcG target genes and redistribution of H3K27 trimethylation to transposons in Arabidopsis thaliana.

Dimethylation of histone H3 lysine 9 (H3K9m2) and trimethylation of histone H3 lysine 27 (H3K27m3) are two hallmarks of transcriptional repression in many organisms. In Arabidopsis thaliana, H3K27m3 is targeted by Polycomb Group (PcG) proteins and is associated with silent protein-coding genes, while H3K9m2 is correlated with DNA methylation and is associated with transposons and repetitive sequences. Recently, ectopic genic DNA methylation in the CHG context (where H is any base except G) has been observed in globally DNA hypomethylated mutants such as met1, but neither the nature of the hypermethylated loci nor the biological significance of this epigenetic phenomenon have been investigated. Here, we generated high-resolution, genome-wide maps of both H3K9m2 and H3K27m3 in wild-type and met1 plants, which we integrated with transcriptional data, to explore the relationships between these two marks. We found that ectopic H3K9m2 observed in met1 can be due to defects in IBM1-mediated H3K9m2 demethylation at some sites, but most importantly targets H3K27m3-marked genes, suggesting an interplay between these two silencing marks. Furthermore, H3K9m2/DNA-hypermethylation at these PcG targets in met1 is coupled with a decrease in H3K27m3 marks, whereas CG/H3K9m2 hypomethylated transposons become ectopically H3K27m3 hypermethylated. Our results bear interesting similarities with cancer cells, which show global losses of DNA methylation but ectopic hypermethylation of genes previously marked by H3K27m3

Endophytes for Improving Ryegrass Performance: Current Status and Future Possibilities

The endophyte N. lolii was introduced naturally into New Zealand and Australia when perennial ryegrass seed was brought into these countries. Although the presence of the endophyte was recognised early in the 19th Century, its effects were only discovered in the early 1980s when it was found that these Wild-type strains of endophyte caused ryegrass staggers, a neuromuscular condition of grazing animals (Fletcher and Harvey 1981), and that they also protected their hosts from the effects of Argentine stem weevil (Listronotus bonariensis) a serious pest of ryegrass in New Zealand (Prestidge et al. 1982). These endophytes form systemic infections in the above-ground parts of their host plants, have no external stage and are maternally transmit-ted in seed. They produce alkaloids which have effects on herbivores, including sheep, cattle and invertebrates. Although all the alkaloids known to be produced by the endophytes have bioactivity against insects, not all are toxic to livestock. Research in New Zealand has focused on exploiting these endophytes for their natural biological control properties while minimising any effects on livestock