Do not log-transform count data

1. Ecological count data (e.g., number of individuals or species) are often log-transformed to satisfy parametric test assumptions.
2. Apart from the fact that generalized linear models are better suited in dealing with count data, a log-transformation of counts has the additional quandary in how to deal with zero observations. With just one zero observation (if this observation represents a sampling unit), the whole dataset needs to be fudged by adding a value (usually 1) before transformation. 
3. Simulating data from a negative binomial distribution, we compared the outcome of fitting models that were transformed in various ways (log, square-root) with results from fitting models using Poisson and negative binomial models to untransformed count data. 
4. We found that the transformations performed poorly, except when the dispersion was small and the mean counts were large.  The Poisson and negative binomial models consistently performed well, with little bias

'Yellow Syndrome' in scleractinian corals throughout Bintain District, Kepulauan Riau Province, Indonesia

Coral disease surveys were conducted in Bintan, Kepulauan Riau Province. The purpose was to identify the abundance of corals showing signs of Yellow Syndrome (YS) disease and to describe similar pathological signs to that of AYBD throughout Bintan District. Three belt transects (2 m x 50 m in size) were set up to determine the abundance of coral reef attacked by YS disease. Line intercept transects were used to determine the percentage of live corals in the surveyed areas. The survey showed that the YS disease syndrome attacked 8 different genera i.e. Acropora, Montipora, Porites, Pavona, Turbinaria, Favia, Platygyra, and Favites. The highest attack happened at Mapur Island (0.06 kol/m2 ) on Porites lutea, Turbinaria peltata, T. mesenterina, Acropora bruggemanni, and Pavona frondifera. The survey also indicated that there may have been at least two types of YS i.e. the first type caused by a boring and/or over-growing sponge species and the second type caused by a kind of pathogenic microbe. Regardless the causal agent of YS, the severity of YS attack on coral urged immediate action to be undertaken and should include initial microscopic and histology examinations. Based on this initial microscopic and histology examinations it was found out that YS bears a close resemblance to the Arabian Yellow Band Disease. This study, however, argued that the word “disease” may have been incorrectly used without identifying a specific causal agent

Mathematical modelling and solutions to Flow Acoustical problems

ABSTRACT The goal of this thesis is to create a guide containing explanations and solutions to flow acoustic problems, which can be used by engineers who are not familiar to this specific area. Since the subject of “flow acoustics” is very wide, this thesis concentrates on solutions to a number of specific case studies, while also explaining the underlying theories. The thesis mainly focuses on internally generated sound, such as in ducts. The thesis also explains and gives walk through guides to some simulation tools that can be used for visualizing flow acoustic phenomena. The different theoretical models that are used to make the simulations are explained and compared so that the right model can be chosen for each specific application

Analisis Formulasi Strategi Bisnis Dalam Mengahadapi Persaingan Industri Doorsmeer (Kasus: Penerapan Analisis Swot Pada Ritonga Doorsmeer Duri-Riau)

This study was conducted in Ritonga Doorsmeer thorns. This business is engaged in vehicle wash services. The purpose of this study is to formulate business strategies in Ritonga Doorsmeer.This research is a descriptive qualitative approach which in this study did not use the sample population only uses key informants to obtain the required information. The data used are primary and secondary data.From the analysis it can be seen that there are some alternative strategies that can be used as a tool to win the competition in the industry doorsmeer Ritonga. And the results of this analysis to formulate long-term strategies

Thromboxane receptor stimulation inhibits adenylate cyclase and reduces cyclic AMP-mediated inhibition of ADP-evoked responses in fura-2-loaded human platelets

AbstractStimulation of human platelets with the thromboxane A2 analogue, U46619, after treatment with prostaglandin E1 or forskolin, reduced the inhibition of ADP-evoked Mn2+ influx and the release of Ca2+ from intracellular stores, U46619 decreased the elevated concentration of 3′, 5′-cyclic AMP in platelets that were pretreated with prostaglandin E1. These results suggest that occupation of prostaglandin H2/thromboxane A2 receptors. like those for other agonists, inhibits adenylate cyclase activity, which can contribute to the promotion of platelet activation

Generalized spin mapping for quantum-classical dynamics

We recently derived a spin-mapping approach for treating the nonadiabatic dynamics of a two-level system in a classical environment [J. Chem. Phys. 151, 044119 (2019)] based on the well-known quantum equivalence between a two-level system and a spin-1/2 particle. In the present paper, we generalize this method to describe the dynamics of $N$-level systems. This is done via a mapping to a classical phase space that preserves the $SU(N)$-symmetry of the original quantum problem. The theory reproduces the standard Meyer--Miller--Stock--Thoss Hamiltonian without invoking an extended phase space, and we thus avoid leakage from the physical subspace. In contrast with the standard derivation of this Hamiltonian, the generalized spin mapping leads to an $N$-dependent value of the zero-point energy parameter that is uniquely determined by the Casimir invariant of the $N$-level system. Based on this mapping, we derive a simple way to approximate correlation functions in complex nonadiabatic molecular systems via classical trajectories, and present benchmark calculations on the seven-state Fenna--Matthews--Olson complex. The results are significantly more accurate than conventional Ehrenfest dynamics, at a comparable computational cost, and can compete in accuracy with other state-of-the-art mapping approaches.Comment: 22 pages, 14 figure