Gaussian distributions on Riemannian symmetric spaces, random matrices, and planar Feynman diagrams

Gaussian distributions can be generalized from Euclidean space to a wide class of Riemannian manifolds. Gaussian distributions on manifolds are harder to make use of in applications since the normalisation factors, which we will refer to as partition functions, are complicated, intractable integrals in general that depend in a highly non-linear way on the mean of the given distribution. Nonetheless, on Riemannian symmetric spaces, the partition functions are independent of the mean and reduce to integrals over finite dimensional vector spaces. These are generally still hard to compute numerically when the dimension (more precisely the rank $N$) of the underlying symmetric space gets large. On the space of positive definite Hermitian matrices, it is possible to compute these integrals exactly using methods from random matrix theory and the so-called Stieltjes-Wigert polynomials. In other cases of interest to applications, such as the space of symmetric positive definite (SPD) matrices or the Siegel domain (related to block-Toeplitz covariance matrices), these methods seem not to work quite as well. Nonetheless, it remains possible to compute leading order terms in a large $N$ limit, which provide increasingly accurate approximations as $N$ grows. This limit is inspired by realizing a given partition function as the partition function of a zero-dimensional quantum field theory or even Chern-Simons theory. From this point of view the large $N$ limit arises naturally and saddle-point methods, Feynman diagrams, and certain universalities that relate different spaces emerge

KELAS KATA DALAM BAHASA DAYAK KETUNGAU SESAT

AbstractThis research is focused on word class in Dayak’s language of Ketungau Sesat. Theword’s class includes nouns, verbs, adjectives, and also adverbs. Each class of words isanalyzed based on its form, meaning and function. The researcher focuses this research onthe morphological aspects with the problem of the research in the form, meaning andfunction of nouns, verbs, adjectives, and adverbs in the Dayak’s language of KetungauSesat. In this research, the researcher uses qualitative research methods and descriptiveforms. The source of the data in this study is Dayak Ketungau Sesat’s language speech inthe form of a class of words spoken by several informants. The data in this study are wordclasses which include form, meaning, and function. The techniques used by the researcherin data collection are elicitation, proficient, pursuing, face-to-face, and note-takingtechniques. Data collection tools used in this research are interview and writinginstruments, and also voice recorder. Based on the research conducted, the researchersucceeded in describing the form, meaning and function of nouns, verbs, adjectives, andadverbs in the Dayak Ketungau Sesat language.Keywords: Word Class, Dayak’s language of Ketungau Sesat

Spectrum and diffusion for a class of tight-binding models on hypercubes

We propose a class of exactly solvable anisotropic tight-binding models on an infinite-dimensional hypercube. The energy spectrum is analytically computed and is shown to be fractal and/or absolutely continuous according to the value hopping parameters. In both cases, the spectral and diffusion exponents are derived. The main result is that, even if the spectrum is absolutely continuous, the diffusion exponent for the wave packet may be anything between 0 and 1 depending upon the class of models.Comment: 5 pages Late

Direct-fed microbes: A tool for improving the utilization of low quality roughages in ruminants

Due to probable toxicity problems to the host animals, these feed additives are not routinely used (Salem et al. 2014a, b). Recently, a great awareness from public health aspects such as residues of these chemicals in milk and meat, and bacterial resistance to antibiotics as a result of increased use in the food chains prohibits their use as feed additives (Barton 2000). These supplements have been criticized by the consumers’ organizations on the ground of product safety and quality. The consumers’ demands have stimulated to search for natural alternatives to chemical feed additives. Supplementation with probiotics that can survive in the rumen has become a suitable alternative (Fon and Nsahlai 2013).For many years, ruminant nutritionists and microbiologists have been interested in manipulating the microbial ecosystem of the rumen to improve production efficiency of different ruminant species. Removal and restriction of antibiotics subtherapeutic uses from ruminant diets has amplified interest in improving nutrient utilization and animal performance and search for more safe alternatives. Some bacterial and fungal microorganisms as a direct-fed microbial (DFM) can be the most suitable solutions. Microorganisms that are commonly used in DFM for ruminants may be classified mainly as lactic acid producing bacteria (LAB), lactic acid utilizing bacteria (LUB), or other microorganism’s species like Lactobacillus, Bifidobacterium, Enterococcus, Streptococcus, Bacillus, Propionibacterium, Megasphaera elsdenii and Prevotellabryantii, in addition to some fungal species of yeast such as Saccharomyces and Aspergillus. A definitive mode of action for bacterial or fungal DFM has not been established; although a variety of mechanisms have been suggested. Bacterial DFM potentially moderate rumen conditions, and improve weight gain and feed efficiency. Fungal DFM may reduce harmful oxygen from the rumen, prevent excess lactate production, increase feed digestibility, and alter rumen fermentation patterns. DFM may also compete with and inhibit the growth of pathogens, immune system modulation, and modulate microbial balance in the gastrointestinal tract. Improved dry matter intake, milk yield, fat corrected milk yield and milk fat content were obtained with DFM administration. However, the response to DFM is not constant; depending on dosages, feeding times and frequencies, and strains of DFM. Nonetheless, recent studies have supported the positive effects of DFM on ruminant performance

Group versus individual academic detailing to improve the use of antihypertensive medications in primary care: a cluster-randomized controlled trial

Purpose To compare group versus individual academic detailing to increase diuretic or β-blocker use in hypertension. Methods We conducted a cluster-randomized controlled trial in a large health maintenance organization. Subjects (N=9820) were patients with newly treated hypertension in the year preceding the intervention (N=3692), the 9 months following the intervention (N=3556), and the second year following intervention (N=2572). We randomly allocated 3 practice sites to group detailing (N=227 prescribers), 3 to individual detailing (N=235 prescribers), and 3 to usual care (N=319 prescribers). Individual detailing entailed a physician-educator meeting individually with clinicians to address barriers to prescribing guideline-recommended medications. The group detailing intervention incorporated the same social marketing principles in small groups of clinicians. Results In the first year following the intervention, the rates of diuretic or β-blocker use increased by 13.2% in the group detailing practices, 12.5% in the individual detailing practices, and 6.2% in the usual care practices. As compared with usual care practices, diuretic or β-blocker use was more likely in group detailing practices (adjusted odds ratio (OR), 1.40; 95% confidence interval (CI), 1.11 – 1.76) and individual detailing practices (adjusted OR, 1.30; 95% CI, 0.95 – 1.79). Neither intervention affected blood pressure control. Two years following this single-visit intervention, there was still a trend suggesting a persistent effect of individual (OR, 1.22; 95% CI, 0.92 – 1.62), but not group, detailing (OR, 1.06; 95% CI, 0.80 – 1.39), as compared with usual care. Conclusion Both group and individual academic detailing improved antihypertensive prescribing over and above usual care but may require reinforcement to sustain improvements

Student Abstract Competition

Articlehttp://deepblue.lib.umich.edu/bitstream/2027.42/97000/1/UMURJ-Issue07_2010-StudentAbstractCompetition.pd

Effects of Saccharomyces cerevisiae at direct addition or pre-incubation on in vitro gas production kinetics and degradability of four fibrous feeds

The aim of this study was to determine effects of increasing doses of the yeast (Saccharomyces cerevisiae) in two methods of applications (direct or 72 h of pre-incubation) on in vitro GP, degradability and some ruminal fermentation parameters of the fibrous feedstuffs of corn stover, oat straw, sugarcane bagasse, and sorghum straw.The objective of this study was to evaluate the effects of Saccharomyces cerevisiae on in vitro gas production (GP) kinetics and degradability of corn stover, oat straw, sugarcane bagasse and sorghum straw. Feedstuffs were incubated with different doses of yeast [0, 4, 8 and 12 mg/g dry matter (DM)] at direct addition or 72 h pre-incubation. Rumen GP was recorded at 2, 4, 6, 8, 10, 12, 14, 24, 30, 48, 54 and 72 h of incubation. After 72 h, rumen pH and methane were determined and contents were filtrated for DM, neutral (NDF) and acid detergent fibre (ADF) degradability. Fibrous species×method of application×yeast interactions occurred (P<0.001) for all measured ruminal GP parameters and degradability. The direct addition or 72 h pre-incubation of S. cerevisiae with corn stover improved (P<0.05) GP and methane and decreased (P<0.05) the lag time (L) and NDF degradability (NDFD). The direct addition of S. cerevisiae to oat straw increased (P<0.05) rate of GP (c) and decreased (P<0.05) asymptotic GP (b). However, 72 h pre-incubation increased (P<0.05) c with linearly decreased b, DM degradability (DMD) and NDFD. Applying S