鱼类个性测定方法研究进展

动物个性是指在不同时空条件下动物种内个体间行为的稳定差异。鱼类个性的研究历史已超过50年,但不同时期和不同研究的鱼类个性测定方法存在较大差异,缺乏一个规范的用于量化鱼类个性研究的方法论。本文作者认为,关注鱼类个性的常规测定方法,了解现有个性定义及其生态学意义,规范鱼类个性的常规实验方法是有必要的。本文所涉及的个性是指狭义上的个性,即对勇敢性、探索性、活跃性、好斗性和社会性等个性的研究方法进行综述,规范了鱼类个性的常规测定方法及注意事项,并对过往研究中鱼类个性测定方法的不足之处进行了讨论和展望。     

Design a system for measuring individual cow feed intake in commercial dairies

Monitoring individual cow feed intake is necessary for calculating the cow individual feed efficiency. The cost and maintenance time necessary for research systems make them impractical for most of the commercial producers. We developed a measurement system with producer convenience and low investment as key design criteria. The goal of this study was to design the system and validate its ability to rank cows by their feed conversion efficiency in commercial farms. The new system consisted of three principal parts: (a) a hanging weighing system, (b) a visual cow identification system and (c) an automatic cleaning system. The weighing system consisted of hanging a single load cell to provide feed mass measurements. The image-based cow identification system (replacing Radio-Frequency Identification) entailed cameras installed above the feeding area and an image processing algorithm that recognized cows by their collar numbers. The new system worked within normal farm routines: the feed supplying truck distributed the animal feed, and a tractor cleaned feed residual. To validate the accuracy and convenience of the system and to rank the cows by their efficiency, an experiment with six scales and 12 cows was conducted in a research barn, succeeded by eight-scale system in a commercial farm with 16 cows. The feed intake of each cow participating in the experiments was monitored for one month. The validation experiment showed that the system had the following specification: scales were accurate within 120 g; the visual cow identification rate was greater than 96%; feeding duration was accurate to 52 s; and routine farm practices (feed distribution, pushing, and residual removal) continued as usual. The cost for a feeding station (utilized consequently for a number of cows) was about 1 500 USD. An example of application of the system to rank cows by their efficiency under commercial conditions was shown. The system can potentially be used for ranking cows by their efficiency in commercial facilities.     

Automatic individual calibration in fall detection – an integrative ambulatory measurement framework

The objective of the current study was to demonstrate the utility of a new integrative ambulatory measurement (IAM) framework by developing and evaluating an individual calibration function in fall detection application. Ten healthy elderly persons were involved in a laboratory study and tested in a protocol comprising various types of activities of daily living and slip-induced backward falls. Inertial measurement units attached to the trunk and thigh segments were used to measure trunk angular kinematics and thigh accelerations. The effect of individual calibration was evaluated with previously developed fall detection algorithm. The results indicated that with individual calibration, the fall detection performance achieved approximately the same level of sensitivity (100% vs. 100%) and specificity (95.25% vs. 95.65%); however, response time was significantly lower than without (249 ms vs. 255 ms). It was concluded that the automatic individual calibration using the IAM framework improves the performance of fall detection, which has a greater implication in preventing/minimising injuries associated with fall accidents.     

The Contribution of TRPV4-Mediated Calcium Signaling to Calcium Homeostasis in Endothelial Cells

A large variety of cation transport systems are involved in the regulation of calcium homeostasis in endothelial cells. The focus of the present study is to determine the contribution of nonselective cation channels from the TRP (transient receptor potential) family to cellular calcium homeostasis of porcine aortic endothelial cells (PAEC). One member of the TRPV (vanniloid) subfamily, TRPV4, has previously been shown to be involved in cation transport induced by a large variety of stimulations including osmolarity, temperature, mechanical stress, and phosphorylation. Here, we demonstrate the existence of several TRP proteins, including TRPV4, in PAEC using RT-PCR. To test whether this channel is functional, we performed FURA-2 calcium measurements and whole-cell patch-clamp experiments. We observed the induction of large calcium signals following mechanical stress, altered extracellular temperature, and the selective TRPV4 activator 4-α -PDD. These effects were diminished in the presence of the TRPV4 inhibitor miconazole, suggesting the involvement of this channel in mediating endothelial calcium signals. The large amounts of transported calcium and the short signaling ways suggest a potentially important role of this channel in many physiological processes.     

Fabrication,Operation and Flow Visualization in Surface-acoustic-wave-driven Acoustic-counterflow Microfluidics

Surface acoustic waves (SAWs) can be used to drive liquids in portable microfluidic chips via the acoustic counterflow phenomenon. In this video we present the fabrication protocol for a multilayered SAW acoustic counterflow device. The device is fabricated starting from a lithium niobate (LN) substrate onto which two interdigital transducers (IDTs) and appropriate markers are patterned. A polydimethylsiloxane (PDMS) channel cast on an SU8 master mold is finally bonded on the patterned substrate. Following the fabrication procedure, we show the techniques that allow the characterization and operation of the acoustic counterflow device in order to pump fluids through the PDMS channel grid. We finally present the procedure to visualize liquid flow in the channels. The protocol is used to show on-chip fluid pumping under different flow regimes such as laminar flow and more complicated dynamics characterized by vortices and particle accumulation domains.     

Rapid apoplastic pH measurement in Arabidopsis leaves using a fluorescent dye

In plants, the extracellular space (apoplast) is one of the main places where exchange of molecules occurs between cells. Not only is this compartment involved in the storage of multiple metabolites and ions, including calcium and protons, but it also plays a role in the transmission of signaling molecules for cell-to-cell communication. It has recently been shown multiple times that these two aspects are linked and can influence each other. In particular, apoplast pH was shown as a primary regulator of auxin (IAA) transport in Arabidopsis thaliana. To prove the role of apoplastic pH, we have developed a protocol for apoplastic fluid extraction from Arabidopsis leaves, followed by pH determination using the 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) fluorescent dye. This technique successfully allows one to monitor apoplastic pH variations among different plant lines and to link changes in apoplastic pH to cellular responses in the plant.     

SIMEX for correction of dietary exposure effects with Box-Cox transformed data

Modelling dietary data, and especially 24-hr dietary recall (24HDR) data, is a challenge. Ignoring the inherent measurement error (ME) leads to biased effect estimates when the association between an exposure and an outcome is investigated. We propose an adapted simulation extrapolation (SIMEX) algorithm for modelling dietary exposures. For this purpose, we exploit the ME model of the NCI method where we assume the assumption of normally distributed errors of the reported intake on the Box-Cox transformed scale and of unbiased recalls on the original scale. According to the SIMEX algorithm, remeasurements of the observed data with additional ME are generated in order to estimate the association between the level of ME and the resulting effect estimate. Subsequently, this association is extrapolated to the case of zero ME to obtain the corrected estimate. We show that the proposed method fulfils the key property of the SIMEX approach, that is, that the MSE of the generated data will converge to zero if the ME variance converges to zero. Furthermore, the method is applied to real 24HDR data of the I.Family study to correct the effects of salt and alcohol intake on blood pressure. In a simulation study, the method is compared with the NCI method resulting in effect estimates with either smaller MSE or smaller bias in certain situations. In addition, we found our method to be more informative and easier to implement. Therefore, we conclude that the proposed method is useful to promote the dissemination of ME correction methods in nutritional epidemiology.     

Inertial sensor based method for identifying spherical joint center of rotation

The miniaturized wireless inertial measurement unit (IMU) technology and algorithms presented herein promote rapid and accurate predictions of the center-of-rotation (CoR) for ball/spherical joints. The algorithm improves upon existing IMU-based methods by directly utilizing the measured acceleration and angular velocity provided by the IMU to deduce the CoR in lieu of relying on error-prone velocity and position estimates. Results demonstrate that this new method resolves the position of the CoR to within a 3 mm sphere of the true CoR determined by a precision coordinate measuring machine. Such accuracy may render this method attractive for broad use in field, laboratory and clinical settings requiring non-invasive and rapid estimates of joint CoR.     

农地保护的外部效益测算——选择实验法在武汉市的应用

农地保护的外部效益是农地保护补偿政策制定的依据.对外部效益进行了理论界定和实证测算,认为农地保护的外部效益是农村集体和农地使用者以外个体从农地保护中得到的收益,通常是非市场收益,对其测算应区分外部效益的内部(外部效益发出者)和外部(外部效益接受者),并确定外部区域的范围.实证利用选择实验模型对武汉市5个区域进行了支付意愿测算,在内外部划分的基础上估算了武汉市农地保护的外部效益并比较了不同方法下外部效益测算结果的差别.结果表明,武汉市耕地、园地、林地和农村水面的外部效益分别为30773.2,653860.0,119267.0和82472.7元/hm2;用行政区域直接代替外部性影响区域的做法会使耕地外部效益的测算结果偏高,也会造成园地、林地和农村水面测算的误差,为避免这类误差,外部性测算及相关补偿、税费政策应考虑内外部区域的划分.     

Primary Structure of a Cysteine Proteinase Inhibitor from the Fruit of Avocado (Persea americana Mill)

The complete amino acid sequence of a proteinaceous cysteine proteinase inhibitor from the fruit of avocado (avocado cystatin) is presented. The protein consists of 100 amino acid residues and has a molecular mass of 11,300 Da. Comparison of this sequence with sequences of plant cysteine proteinase inhibitors (phytocystatins), including oryzacystatins I and II from rice seeds, cowpea cystatin, and corn cystatin, showed that the avocado cystatin molecule has 60% and 54% residues identical with the two forms of the rice seed proteins, oryzacystatins I and II, respectively, and 64% and 63% with the cowpea and corn proteins, respectively. The totally conserved sequence, Gln-Val-Val-Ala-Gly, among several of the animal cystatins as well as phytocystatins, is at positions 47-51 in the avocado cystatin molecule.