Eggs mimicry of Common Cuckoo (Cuculus canorus) utilizing Ashy-throated Parrotbill (Paradoxornis alphonsianus) host

Polymorphism in egg coloration is prominent in the Common Cuckoo (Cuculus canorus) and a common host, the Ashy-throated Parrotbill (Paradoxornis alphonsianus). Egg polymorphism has probably evolved as a consequence of frequency-dependent selection in both host and parasite, and has, according to human vision, resulted in discrete immaculate white, pale blue and blue egg phenotypes within a single population. However, egg mimicry assessment is not always straightforward, and previous studies have shown that human based comparisons applied to the coloration of bird eggs may be inadequate. Here, we objectively quantify egg color of both parasite and host by spectrophotometry and assess egg mimicry of the Common Cuckoo to the eggs of its Ashy-throated Parrotbill host. Our results revealed that egg reflectance spectra agree well with the assessment based on human vision that cuckoo eggs mimic those of the parrotbill host, in both visible (VIS) and ultraviolet (UV) ranges. However, the white cuckoo egg shows slightly poorer mimicry than the blue cuckoo egg in corresponding host clutches. We suggest that the white parrotbill egg morph (and subsequently the whitish cuckoo egg color) may have evolved after the evolution of the blue egg morph due to strong selection from parasites in the cuckoo-parrotbill system.

用真诚的爱促使后进生转化

后进生的转化作为教育创新的难点,是一项复杂艰苦的工作,方法虽有多种多样,但关键在于教师的态度和情感投入。多年的教育教学实践,使我深刻地意识到,当我们面对后进生,特别是那些由于非智力因素而暂时学习上有障碍的学生,如果对他们过多地进行责备、批评、训斥,找家长告状,非但无济于事,而且还可能导致其产生逆反心理,结果是适得其反,愈来愈差,形成一种恶性循环。相反,如果我们老师教育艺术得当。

Transition‐metal‐free three‐component acetalation‐pyridylation of alkenes via photoredox catalysis

A general transition‐metal‐free photoinduced acetalation‐pyridylation of alkenes using diethoxyacetic acid and cyanopyridine was developed under mild conditions.By employing 4CzIPN as the photocatalyst and Cs_(2)CO_(3) as the base,a diverse range of styrene derivatives and cyanopyridines worked well to give the desired products.The versatility of this method is highlighted by its application in the construction of various functional groups and the late‐stage modification of drugs.Importantly,some of the synthesized compounds showed good in vitro antitumor activity,indicating that this protocol is of significance and potential for antitumor drug development.

Pathogenetic Consequences of Cytomegalovirus-Host Co-evolution

Co-evolution has been shown to result in an adaptive reciprocal modification in the respective behaviors of interacting populations over time. In the case of host-parasite co-evolution,the adaptive behavior is most evident from the reciprocal change in fitness of host and parasite-manifested in terms of pathogen survival versus host resistance. Cytomegaloviruses and their hosts represent a pairing of populations that has co-evolved over hundreds of years. This review explores the pathogenetic consequences emerging from the behavioral changes caused by co-evolutionary forces on the virus and its host.

Route and Rethink of China＇s Directly Applicable Law

Directly Applicable Law is an important achievement theory of private international law in the late nineteen fifties, widely used by states. The people＇ s Republic of China foreign civil legal relationship applicable law established the frame of our country＇ s Directly Applicable Law in the legislative level. In practice, there exists some shortcomings in the use of the rules and theory of Directly Applicable Law. In this paper, the author defines the rules from the micro level to order picture from macro level as the starting point, discussed the perfect approach of Directly Applicable Law from the dimension of the interpretation, system, evolution route ,and rethought our current legislative situation.

Improved Sinusoid Analysis and Post-Processing in Parametric Audio Coding

This paper proposed improvements to the low bit rate parametric audio coder with sinusoid model as its kernel. Firstly, we propose a new method to effectively order and select the perceptually most important sinusoids. The sinusoid which contributes most to the reduction of overall NMR is chosen. Combined with our improved parametric psychoacoustic model and advanced peak riddling techniques, the number of sinusoids required can be greatly reduced and the coding efficiency can be greatly enhanced. A lightweight version is also given to reduce the amount of computation with only little sacrifice of performance. Secondly, we propose two enhancement techniques for sinusoid synthesis: bandwidth enhancement and line enhancement. With little overhead, the effective bandwidth can be extended one more octave; the timbre tends to sound much brighter, thicker and more beautiful.

Coevolution of brachiopod paleobiogeography and tectonopaleogeography during the late Paleozoic in Central Asia

Patterns of brachiopod paleobiogeographic regionalization in Central Asia reveal a coevolution between brachiopod paleobiogeography and tectonopaleogeography during the Early Devonian,Early Carboniferous,Late Carboniferous,Early Permian,and Middle Permian.The coevolutionary relationship reasonably accounts for the formation mechanisms of brachiopod paleobiogeography in this region,and also provides a basis for studies on the location and configuration of oceans and plates(blocks)during the late Paleozoic in Central Asia.

An adaptive time stepping method with efcient error control for second-order evolution problems

This work is concerned with time stepping finite element methods for abstract second order evolution problems. We derive optimal order a posteriori error estimates and a posteriori nodal superconvergence error estimates using the energy approach and the duality argument. With the help of the a posteriori error estimator developed in this work, we will further propose an adaptive time stepping strategy. A number of numerical experiments are performed to illustrate the reliability and efficiency of the a posteriori error estimates and to assess the effectiveness of the proposed adaptive time stepping method.