Effects of elevation on litter-size variation among lizard populations in the Sceloporus grammicus complex (Phrynosomatidae) in Mexico

We examined the effect of elevation on litter-size variation in viviparous lizards of the Sceloporus grammicus complex in 10 states of Mexico. Female snout–vent length (SVL) decreased with increasing elevation, and absolute litter size based on embryos also tended to de crease with increasing elevation. However, after controlling for variation in female body size, we found that litter sizes tended to be relatively larger at higher elevation. Elevation therefore appears to influence litter size in these lizards; however, relatively little of the variation is explained by elevation; thus, other factors are likely making substantial contributions to the observed litter-size variation. The S. grammicus complex appears to be a good model system for examining the underlying causes of geographic and elevational variation in lizard life histories. Examinamos el efecto del altitud en la variación del tamaño de camada de las lagartijas vivíparas del complejo Sceloporus grammicus en 10 estados de México. La LHC de las hembras disminuyó con la altitud, y el tamaño absoluto de camada, calculado con base en el número de embriones, también tendió a disminuir. No obstante, después de controlar la variación en el tamaño corporal de las hembras, encontramos que los tamaños de camada tendieron a ser relativamente más grandes en altitudes mayores. La altitud, por tanto, parece influir en el tamaño de camada de estas lagartijas; sin embargo, la altitud explica relativamente poco de la variación, por lo que, es probable que otros factores contribuyan substancialmente a la variación observada en el tamaño de camada. El complejo S. grammicus parece ser un buen sistema para estudiar las causas fundamentales de la variación geográfica y altitudinal en la historia de vida de las lagartijas.     

一个Bocs的表示范畴（Ⅳ）──M（x）＝J_1⊕J_2⊕J_3的情形

证明了对于一般的Ｍ∈Ｒ，Ｍ（ｘ）＝Ｊ１Ｊ２Ｊ３，在Ｒ中存在始于（终于）Ｍ的左（右）几乎可裂映射。     

一个Bocs的表示范畴（Ⅲ）——若干类齐次几乎可裂序列

定义了Ａ－性质，并给出了Ｒ中的若干类齐次几乎可裂序列。     

The menthol receptor TRPM8 is the principal detector of environmental cold

Sensory nerve fibres can detect changes in temperature over a remarkably wide range, a process that has been proposed to involve direct activation of thermosensitive excitatory transient receptor potential (TRP) ion channels. One such channel--TRP melastatin 8 (TRPM8) or cold and menthol receptor 1 (CMR1)--is activated by chemical cooling agents (such as menthol) or when ambient temperatures drop below approximately 26 degrees C, suggesting that it mediates the detection of cold thermal stimuli by primary afferent sensory neurons. However, some studies have questioned the contribution of TRPM8 to cold detection or proposed that other excitatory or inhibitory channels are more critical to this sensory modality in vivo. Here we show that cultured sensory neurons and intact sensory nerve fibres from TRPM8-deficient mice exhibit profoundly diminished responses to cold. These animals also show clear behavioural deficits in their ability to discriminate between cold and warm surfaces, or to respond to evaporative cooling. At the same time, TRPM8 mutant mice are not completely insensitive to cold as they avoid contact with surfaces below 10 degrees C, albeit with reduced efficiency. Thus, our findings demonstrate an essential and predominant role for TRPM8 in thermosensation over a wide range of cold temperatures, validating the hypothesis that TRP channels are the principal sensors of thermal stimuli in the peripheral nervous system.     

一个bocs的表示范畴（Ⅰ）──象元和射元

在Ａｒｔｉｎ代数的表示理论中，Ｃｒａｗｌｅｙ－Ｂｏｅｖｅｙ证明了一个著名的定理：“令Ａ是一个代数闭域上的有限维代数，如果Ａ是表示Ｔａｍｅ型的，则对任意固定的维数ｄ，几乎所有的维数小于等于ｄ的模具有性质ＤＴｒＭ≈Ｍ．”在证明这一定理的逆定理的过程中，出现了一个有趣的ｂｏｃｓ（Ａ，Ｖ），定义在一个代数闭域ｋ上，带有ｌａｙｅｒＬ＝（Ａ＇；ω；α，ｖ），Ａ＇的不可分解象元集仅由单个元｛Ｘ｝组成，也就是说，Ａ是局部的，其中Ａ＇（Ｘ，Ｘ）＝ｋ，微分是δ（ｘ）＝０，δ（ａ）＝ｘｖ－ｖｘ，δ（ｖ）＝０．一般来说，一个ｂｏｃｓ的表示范畴是很难把握的，它是加性的，但不是Ａｂｅｌ范畴。因而没有正合性，更谈不到几乎可裂序列．但是在这个特殊的ｂｏｃｓ的表示范畴中，我们能构造出若干类象元Ｍ，及其始于且终于Ｍ的几乎可裂序列，也就是说，这类象元具有性质：ＤＴｒ（Ｗ）≈Ｍ，这篇文章刻划ｂｏｃｓ的表示范畴的象元和射元．     

Mustard oils and cannabinoids excite sensory nerve fibres through the TRP channel ANKTM1

Wasabi, horseradish and mustard owe their pungency to isothiocyanate compounds. Topical application of mustard oil (allyl isothiocyanate) to the skin activates underlying sensory nerve endings, thereby producing pain, inflammation and robust hypersensitivity to thermal and mechanical stimuli. Despite their widespread use in both the kitchen and the laboratory, the molecular mechanism through which isothiocyanates mediate their effects remains unknown. Here we show that mustard oil depolarizes a subpopulation of primary sensory neurons that are also activated by capsaicin, the pungent ingredient in chilli peppers, and by Delta(9)-tetrahydrocannabinol (THC), the psychoactive component of marijuana. Both allyl isothiocyanate and THC mediate their excitatory effects by activating ANKTM1, a member of the TRP ion channel family recently implicated in the detection of noxious cold. These findings identify a cellular and molecular target for the pungent action of mustard oils and support an emerging role for TRP channels as ionotropic cannabinoid receptors.     

Flow signaling and atherosclerosis

Atherosclerosis rarely develops in the region of arteries exposed to undisturbed flow (u-flow, unidirectional flow). Instead, atherogenesis occurs in the area exposed to disturbed flow (d-flow, multidirectional flow). Based on these general pathohistological observations, u-flow is considered to be athero-protective, while d-flow is atherogenic. The fact that u-flow and d-flow induce such clearly different biological responses in the wall of large arteries indicates that these two types of flow activate each distinct intracellular signaling cascade in vascular endothelial cells (ECs), which are directly exposed to blood flow. The ability of ECs to differentially respond to the two types of flow provides an opportunity to identify molecular events that lead to endothelial dysfunction and atherosclerosis. In this review, we will focus on various molecular events, which are differentially regulated by these two flow types. We will discuss how various kinases, ER stress, inflammasome, SUMOylation, and DNA methylation play roles in the differential flow response, endothelial dysfunction, and atherosclerosis. We will also discuss the interplay among the molecular events and how they coordinately regulate flow-dependent signaling and cellular responses. It is hoped that clear understanding of the way how the two flow types beget each unique phenotype in ECs will lead us to possible points of intervention against endothelial dysfunction and cardiovascular diseases.     

Calcium-sensitive potassium channelopathy in human epilepsy and paroxysmal movement disorder

The large conductance calcium-sensitive potassium (BK) channel is widely expressed in many organs and tissues, but its in vivo physiological functions have not been fully defined. Here we report a genetic locus associated with a human syndrome of coexistent generalized epilepsy and paroxysmal dyskinesia on chromosome 10q22 and show that a mutation of the alpha subunit of the BK channel causes this syndrome. The mutant BK channel had a markedly greater macroscopic current. Single-channel recordings showed an increase in open-channel probability due to a three- to fivefold increase in Ca(2+) sensitivity. We propose that enhancement of BK channels in vivo leads to increased excitability by inducing rapid repolarization of action potentials, resulting in generalized epilepsy and paroxysmal dyskinesia by allowing neurons to fire at a faster rate. These results identify a gene that is mutated in generalized epilepsy and paroxysmal dyskinesia and have implications for the pathogenesis of human epilepsy, the neurophysiology of paroxysmal movement disorders and the role of BK channels in neurological disease.