In the Mammalia, vestigial skeletal structures abound but have not previously been the focus of study, with a few exceptions (e.g., whale pelves). Here we use a phylogenetic bracketing approach to identify vestigial structures in mammalian postcranial skeletons and present a descriptive survey of such structures in the Mammalia. We also correct previous misidentifications, including the previous misidentification of vestigial caviid metatarsals as sesamoids. We also examine the phylogenetic distribution of vestigiality and loss. This distribution indicates multiple vestigialization and loss events in mammalian skeletal structures, especially in the hand and foot, and reveals no correlation in such events between mammalian fore and hind limbs.

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Limb reduction and loss, with reduction of limb and girdle skeletons to a vestigial state, has occurred several times independently within the skink family (Scincidae). The vestigial appendicular skeletons of most limbless skinks have not been described before now. Here we describe those of eight African skink species, all with a burrowing lifestyle: Acontias percivali, Acontias meleagris, Typhlosaurus cregoi, Typhlosaurus lineatus, Typhlacontias gracilis, Sepsina bayonii, Scelotes anguina and Scelotes arenicola. For all but two (A. meleagris and Sc. arenicola) the appendicular skeletons were previously undescribed. Limbs are absent in all specimens except for vestigial hindlimbs in Se. bayonii and vestigial femurs in one specimen of Sc. arenicola. In our sample, the pectoral girdle is reduced to a pair of tiny slivers in A. percivali, Ty. gracilis, Se. bayonii and Sc. anguina. It is absent in the other specimens. The pelvic girdle is absent in Ty. cregoi. In all the rest but Se. bayonii it is vestigial, retaining only the ilium in A. meleagris, Ty. lineatus and one specimen of Sc. arenicola. This study adds to the number of skink species with vestigial appendicular skeletons that have been described. It also adds to the range of documented intraspecific variation in the vestigial appendicular skeletons of A. meleagris, Sc. arenicola and the Australian skinks Lerista stylis and Lerista carpentariae. We observed asymmetry between the left and right sides in the vestigial appendicular skeletons of four of the African skink species: A. meleagris, Sc. anguina, Sc. arenicola and Se. bayonii.

Heat stress exerts a profound impact on the resistance of plants to parasites. In this research, we investigated the impact of an acute transient heat stress on the resistance of the wheat line ÔMolly,Õ which contains the R gene H13, to an avirulent Hessian ßy (Mayetiola destructor (Say)) population. We found that a signiÞcant portion of Molly seedlings stressed at 40ЊC for 6 h during or after the initial Hessian ßy larval attack became susceptible to otherwise avirulent insects, whereas unstressed control plants remained 100% resistant. SpeciÞcally, 77.8, 73.3, 83.3, and 46.7% of plants heat stressed at 0, 6, 12, and 24 h, respectively, after the initial larval attack became susceptible. Biochemical analysis revealed that heat stress caused a transient decrease in 12-oxo-phytodienoic acid, but an increase in salicylic acid accumulation in Molly plants. The change in phytohormones after heat stress and Hessian ßy infestation was not observed in ÔNewton,Õ a near-isogenic but Hessian ßy susceptible wheat line. Instead, heat stress caused a relatively prolonged reduction in palmitoleic acid. The role of phytohormones in heat-induced loss of wheat resistance was discussed.

Heat stress exerts significant impact on plant-parasite interactions. Phytohormones, such as salicylic acid (SA), play important roles in plant defense against parasite attacks. Here, we studied the impact of a combination of heat stress and exogenous SA on the resistance of wheat (Triticum aestivum L.) plants to the Hessian fly [Mayetiola destructor (Say)]. We found that the wheat cultivar 'Molly', which contains the resistance gene H13, lost resistance to Hessian fly under heat stress (40°C for 3 and 6 h), and that exogenous application of SA on Molly seedlings right before heat stress can partially prevent the loss of resistance of Molly plants under heat conditions. Our findings have significant implications for understanding the dynamics of plant-insect interactions in the context of heat stress.

Nanofibers have gained much interest due to their wide range of applications as gas sensors, filters, super-capacitors, solid-oxide fuel cells, and catalysts. Preparation of one dimensional (1D) nanofibers and nanocomposites via electrospinning is a simple technique, which does not require any chemical precursors in the reactions. It is known that ceria (cerium dioxide, CeO 2 ) possesses a fluorite-type facecentered cubic structure. Such an isotropic structure makes it hard to synthesize 1D material through conventional chemical reactions [1], and thus most of the research on ceria involved nanoparticles. Recently, ceria nanobelts were synthesized by electrodeposition [1], and nanorods by a hydrothermal reaction [2]. However, the nanobelts or nanorods showed limited aspect ratios. Using electrospinning, instead, long ceria nanofibers could be prepared [3]. In this work, we use an electron probe microanalyzer (EPMA) to analyze the ceria nanofibers with chemical dopants. 452