中国兽类一新纪录———爪哇穿山甲

记述了来自中国云南的爪哇穿山甲Manis javanica , 即中国兽类新纪录, 标本收藏在中国科学院昆明动物

Aquatic ecology monitoring: water quality, fish, fish catch, sanitation and disease vectors: monitoring no. 10 and reservoir baseline, 23rd – 30th April 2012

The results reported on were from a monitoring survey No. 10 undertaken between 23 rd and 29th April 2012 during construction period of the Bujagali Hydropower Project (BHPP). Two pre-construction, baseline surveys in April 2000 and April 2006 were conducted and so far, during construction phase of the project, nine monitoring surveys have been undertaken i.e. in September 2007, April 2008, April 2009, October 2009, April 2010, September 2010, April 2011, September 2011and the present one, in April 2012. Since 2009 biannual monitoring surveys have been conducted at an upstream and a downstream transect of the BHPP with emphasis on the following aspects: water quality determinants biology and ecology of fishes and food webs fish stock and fish catch including economic aspects of catch and sanitation/vector studies (bilharzias and river blindness) During this survey, baseline assessment of the above mentioned studies was conducted in the reservoir behind the dam, including studies on algae, zooplankton and benthic macroinvertebrates which had been restrained since April 2008. The findings of baseline assessment of the reservoir are also contained in this report and are compared with those obtained from Transect 1(Upstream) and Transect 2 (Downstream).

Convex approaches to model wavelet sparsity patterns

Statistical dependencies among wavelet coefficients are commonly represented by graphical models such as hidden Markov trees (HMTs). However, in linear inverse problems such as deconvolution, tomography, and compressed sensing, the presence of a sensing or observation matrix produces a linear mixing of the simple Markovian dependency structure. This leads to reconstruction problems that are non-convex optimizations. Past work has dealt with this issue by resorting to greedy or suboptimal iterative reconstruction methods. In this paper, we propose new modeling approaches based on group-sparsity penalties that leads to convex optimizations that can be solved exactly and efficiently. We show that the methods we develop perform significantly better in de-convolution and compressed sensing applications, while being as computationally efficient as standard coefficient-wise approaches such as lasso. © 2011 IEEE.

Re-examination of the coefficient of determination (r2) using road materials engineering case studies

The analysis of scientific data is integral to materials engineering and science. The correlation between measured variables is often quantified by estimating the coefficient of determination or the r2 value. This is the recognised procedure for determining linear relationships. The authors review the derivation of the r2 value and derive an associated quantity, termed the relative deviation (RD), which is the ratio of the root mean square of the deviations about the fitted line to the root mean square of the deviations about the y bar line expressed as a percentage. The relative deviation has an advantage over the coefficient of determination in that it has greater numerical sensitivity to changes in the spread of data about the fitted line, especially when the scatter is small. In addition, the relative deviation is able to define, in percentage terms, the reduction in scatter when different independent variables are correlated with a common dependent variable. Four case studies in the materials field (aggregate crushing value, Atterberg limits, permeability and creep of asphalt) from work carried out at the Queensland Main Roads Department are presented to show the use of the new parameter RD.

Robust filtering and smoothing with gaussian processes

We propose a principled algorithm for robust Bayesian filtering and smoothing in nonlinear stochastic dynamic systems when both the transition function and the measurement function are described by non-parametric Gaussian process (GP) models. GPs are gaining increasing importance in signal processing, machine learning, robotics, and control for representing unknown system functions by posterior probability distributions. This modern way of system identification is more robust than finding point estimates of a parametric function representation. Our principled filtering/smoothing approach for GP dynamic systems is based on analytic moment matching in the context of the forward-backward algorithm. Our numerical evaluations demonstrate the robustness of the proposed approach in situations where other state-of-the-art Gaussian filters and smoothers can fail. © 2011 IEEE.

Real-time block flow tracking of atrial septal defect motion in 4D cardiac ultrasound

Real-time cardiac ultrasound allows monitoring the heart motion during intracardiac beating heart procedures. Our application assists atrial septal defect (ASD) closure techniques using real-time 3D ultrasound guidance. One major image processing challenge is the processing of information at high frame rate. We present an optimized block flow technique, which combines the probability-based velocity computation for an entire block with template matching. We propose adapted similarity constraints both from frame to frame, to conserve energy, and globally, to minimize errors. We show tracking results on eight in-vivo 4D datasets acquired from porcine beating-heart procedures. Computing velocity at the block level with an optimized scheme, our technique tracks ASD motion at 41 frames/s. We analyze the errors of motion estimation and retrieve the cardiac cycle in ungated images. © 2007 IEEE.

Vowel normalisation: Time-domain processing of the internal dynamics of speech

Human listeners can identify vowels regardless of speaker size, although the sound waves for an adult and a child speaking the ’same’ vowel would differ enormously. The differences are mainly due to the differences in vocal tract length (VTL) and glottal pulse rate (GPR) which are both related to body size. Automatic speech recognition machines are notoriously bad at understanding children if they have been trained on the speech of an adult. In this paper, we propose that the auditory system adapts its analysis of speech sounds, dynamically and automatically to the GPR and VTL of the speaker on a syllable-to-syllable basis. We illustrate how this rapid adaptation might be performed with the aid of a computational version of the auditory image model, and we propose that an auditory preprocessor of this form would improve the robustness of speech recognisers.

Effect of water temperature on the growth performance and digestive enzyme activities of Chinese longsnout catfish (Leiocassis longirostris Gunther)

The present study was carried out to investigate the influence of water temperature on the growth performance and digestive enzyme (pepsin, trypsin and lipase) activities of Chinese longsnout catfish. Triplicate groups of Chinese longsnout catfish (35.6 +/- 0.48 g, mean +/- SE) were reared at different water temperatures (20, 24, 28 and 32 degrees C). The feeding rate (FR), specific growth rate (SGR) and feed efficiency ratio (FER) were significantly affected by water temperatures and regression relationships between water temperature and FI, SGR as well as FER were expressed as FR=-0.016T2+0.91T-10.88 (n=12, R2=0.8752), SGR=-0.026T2+1.39T-17.29 (n=12, R2=0.7599) and FER=-0.013T2+0.70T-8.43 (n=12, R2=0.7272). Based on these, the optimum temperatures for FR, SGR and FER were 27.66, 26.69 and 26.44 degrees C respectively. The specific activities of digestive enzymes at 24 or 28 degrees C were significantly higher than that at 20 or 32 degrees C. In addition, there was a significant linear regression between FR or SGR and specific activities of pepsin and lipase, which indicated that pepsin and lipase played important roles in regulating growth through nutrient digestion in Chinese longsnout catfish.

Effects of dietary cyanobacteria of two different sources on growth and recovery of hybrid tilapia (Oreochromis niloticus x O. aureus)

A 115 days feeding trial was conducted to evaluate the effect of dietary cyanobacteria on growth, microcystins (MCs) accumulation in hybrid tilapia (Oreochromis niloticus x O. aureus) and the recovery when the fish were free of cyanobacteria. Three experimental diets were formulated: the control (cyanobacteria free diet); one test diet with cyanobacteria from Lake Taihu (AMt 80.0 mu g MCs g(-1) diet) and one with cyanobacteria from Lake Dianchi (AMd, 410.0 rho g MCs g(-1) diet). Each diet was fed to fish for 60 days and then all fish were free of cyanobacteria for another 55 days. A significant increase in feeding rate (FR) was observed in fish fed AMd diet after a first 30-day exposure (1(st) EP), and in fish fed both AMt diet and AMd diet after a second 30-day exposure (2(nd) EP). Specific growth rates (SGR) of fish fed AMt diet and AMd diet were both obviously affected after the first 30-day exposure, but SGR was only significantly affected in fish fed AMt diet after the second 30-day exposure. After a 55-day recovery, there were no significant differences among diets in the indices mentioned above. Much higher concentrations of MCs were accumulated in tissues of all fish exposed to cyanobacteria. After the 55-day recovery, MC concentrations in fish tissues were significantly lower than those on day 60. (C) 2009 Elsevier Ltd. All rights reserved.

Changes in benthic algal communities following construction of a run-of-river dam

Ecological responses to dam construction are poorly understood, especially for downstream benthic algal communities. We examined the responses of benthic algal communities in downstream reaches of a tributary of the Xiangxi River, China, to the construction of a small run-of-river dam. From February 2003 to August 2006, benthic algae, chemical factors, and habitat characteristics were monitored upstream and downstream of the dam site. This period spanned 6 mo before dam construction and 37 mo after dam construction. Benthic algal sampling yielded 199 taxa in 59 genera that belonged to Bacillariophyta, Chlorophyta, and Cyanophyta. Some physical factors (flow velocity, water depth, and channel width) and 3 algal metrics (diatom species richness, Margalef diversity, and % erect individuals) were significantly affected by the dam construction, whereas chemical factors (e.g., NH4-N, total N, SiO2) were not. Nonmetric multidimensional scaling (NMS) ordinations showed that overall algal assemblage structure downstream of the dam sites was similar to that of upstream control sites before dam construction and for 1 year after dam construction (p > 0.05). However, sites belonging to upstream and downstream reaches were well separated on NMS axis 1 during the 2(nd) and 3(rd) years after dam construction. Our results suggest that impacts of dam construction on benthic algal communities took 2 to 3 y to emerge. Further development of a complete set of indicators is needed to address the impact of small-dam construction. Our observations underscore the need for additional studies that quantify ecological responses to dam construction over longer time spans.