Cochlear supporting cells require GAS2 for cytoskeletal architecture and hearing

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Stable heterometallic fluorinated β-diketonato/alkoxo complexes as precursors for Er-doped luminescence materials

New series of novel heterometallic fluorinated β-diketonato/alkoxo complexes have been synthesized in quantitative yields and characterized by analytical data, FT-IR, NMR and mass spectroscopy. Their thermal behavior was investigated by TGA. The plausible structure of β-diketonato/alkoxo complexes was suggested from the physico-chemical analysis. These complexes have been studied as potential precursors for planar optical amplifiers through the investigation of optical properties and a homogenous thin film spin coating. The volatility of these complexes was reduced by intramolecular hydrogen bonding. The assembling of fluorinated β-diketonato/alkoxo ligands ensures high coordination numbers for coordinated metals and improves their stability in ambient atmosphere.     

Enhancer variants on chromosome 2p14 regulating SPRED2 and ACTR2 act as a signal amplifier to protect against rheumatoid arthritis

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Heterodyne detected nonlinear optical imaging in a lock‐in free manner

We report a compact, cost‐effective tuned amplifier for frequency‐selective amplification of the modulated signal in heterodyne detected nonlinear optical microscopy. Our method improved the signal to noise ratio by an order of magnitude compared to conventional lock‐in detection, as demonstrated through stimulated Raman scattering imaging of live cells and tissues at the speed of 2 μsec/pixel. Application of the tuned amplifier to transient absorption microscopy is also demonstrated. The increased signal to noise ratio allowed epi‐detected in vivo imaging of myelin and blood in rat spinal cord with high spatial resolution. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

An inexpensive and reliable electroantennometer with automatic base line offset and drift canceller

ABSTRACT. An inexpensive and reliable electronic device is described which allows measurement, viewing and recording of electroantennogram (EAG) responses. Potential advantages of the device include low cost, simple operation, suitability for bench or field use, built-in digital readout, separate head amplifier, (+) and (-) peak value memories, and an exclusive automatic offset and drift cancelling circuit which does not introduce distortion. The device is intended for use in EAG recording, where signals with either rapid or slow depolarizations are being measured, bringing important information in the return-to-baseline region, as well as the (+) and (-) peak values of the EAG.     

Body patterns as potential amplifiers of size and condition in a territorial spider

Signal costs, and associated trade-offs, are widely thought of as fundamental to the evolution and maintenance of reliable signals. Contrasting this view, the amplifier mechanism postulates that signals may be deemed reliable by design rather than by costs. Although the idea is not new, investigation of amplifier signals in nature remains scant. Here we show that displays and body markings on the Mediterranean tarantula, Lycosa tarantula (L.) (Lycosidae), are consistent with interpretation as amplifiers of size and body condition. The size of tibia and abdomen ventral markings (which alternate between dark and pale patterns) presented to rivals during contests are highly correlated with body size and condition, respectively. Abdomen markings have the additional feature of placement on a region especially influenced by abdomen distension and therefore has greater proportional variation than the underlying amplified trait. In spite of the differences in size and in body patterns between spiders of two isolated and ecologically different populations, correlation between body marking and dimensions, and relatively high proportional variation of the abdomen markings, was maintained, probably reflecting the adaptive value of these traits. We conducted a feeding experiment which showed that the abdominal markings enlarged (stretched with abdomen distension) at a higher rate if spiders were provided with more food, further supporting the idea that this marking amplifies body condition.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 78 , 355–364.     

Otoacoustic emissions from insect ears having just one auditory neuron

Sensitive hearing organs often employ nonlinear mechanical sound processing which produces distortion-product otoacoustic emissions. Such emissions are also recorded from insect tympanal organs. Here we report high frequency distortion-product emissions, evoked by stimulus frequencies up to 95 kHz, from the tympanal organ of a notodontid moth, Ptilodon cucullina, which contains only a single auditory receptor neuron. The 2f1–f2 distortion-product emission reaches sound levels above 40 dB SPL. Most emission growth functions show a prominent notch of 20 dB depth (n = 20 trials), accompanied by an average phase shift of 119°, at stimulus levels between 60 and 70 dB SPL, which separates a low- and a high-level component. The emissions are vulnerable to topical application of ethyl ether which shifts growth functions by about 20 dB towards higher stimulus levels. For the mammalian cochlea, Lukashkin and colleagues have proposed that distinct level-dependent components of nonlinear amplification do not necessarily require interaction of several cellular sources but could be due to a single nonlinear source. In notodontids, such a physiologically vulnerable source could be the single receptor cell. Potential contributions from accessory cells to the nonlinear properties of the scolopidial hearing organ are still unclear.     

调频蝙蝠对特定频率的抑制在耳蜗微音器电位信号上的反映

目的 蝙蝠耳蜗外听毛细胞产生的耳蜗微音器电位（cochlear microphonic，CM）信号包含有耳蜗基底膜运动的相关信息。本研究旨在通过分析调频（frequency modulation，FM）蝙蝠CM信号与其接收声波频率之间的关系，以探究蝙蝠耳蜗神经对回声定位的影响机制。方法 通过在腹侧耳蜗核放置一组金属电极，记录并分析FM蝙蝠（Eptesicus和Pipistrellus）CM信号对猝发声（tone burst）的刺激响应。结果 两种不同种类的FM蝙蝠（Eptesicus和Pipistrellus）在高声压刺激时，CM信号均值频率响应曲线均表现出在较窄的特定频率段发声明显凹陷。对于Eptesicus，其CM信号均值频率响应曲线在一次谐波和二次谐波的截止频率（terminal frequency，TF）两侧均有明显波谷，这些波谷凹陷从15 kHz起以 15 kHz的频率间隔重复出现；对于Pipistrellus，CM信号均值频率响应曲线仅在一次谐波两侧有明显波谷。结论 CM信号表现出的抑制作用与FM蝙蝠一次谐波和二次谐波TF之间的关系，反映出耳蜗神经对特定频率会产生抑制作用，这种抑制作用有助于蝙蝠提取调制到TF附近的目标定位信息。     

Putting information back into biological communication

At the heart of many debates on communication is the concept of information. There is an intuitive sense in which communication implies the transfer of some kind of information, probably the reason why information is an essential ingredient in most definitions of communication. However, information has also been an endless source of misunderstandings, and recent accounts have proposed that information should be dropped from a formal definition of communication. In this article, we re‐evaluate the merits and the internal logic of information‐based vs. information‐free approaches and conclude that information‐free approaches are conceptually incomplete and operationally hindered. Instead, we propose a functional notion of information that follows logically from previous adaptationist accounts. The ensuing definition of communication provides a wider, more inclusive theoretical scope that reflects more accurately the evolutionary scenario shaping animal signals. Additionally, it is a definition better equipped to deal with the extraordinary diversity of animal signals, facilitates the distinction of honest and deceptive signals at a proximate level and accommodates a number of conceptual and practical issues (e.g. redundancy, alerting components) that are lost when we fail to acknowledge the informative content of animal signals.