Structure of the unusual explosive fruits of the early diverging angiosperm Illicium (Schisandraceae s.l., Austrobaileyales)

All Illicium spp. have explosive fruits, which is a unique character among the basal grade of angiosperms. Illicium fruits consist of several ventrally dehiscing follicles developing from conduplicate carpels, with a prominent, slightly postgenitally fused ventral slit. The closure of the ventral slit is also secured by two mirror‐symmetrical massive longitudinal sclerenchymatous bands in the mesocarp along the edges and by turgor pressure. The pericarp differentiates into a fleshy (or coriaceous) peripheral zone (exocarp and mesocarp) with numerous ethereal‐oil‐containing cells and a sclerenchymatous (single‐layered, palisade) inner zone (endocarp). Dehydration of the fleshy zone of the pericarp and partial compression of the epidermal sclereids with U‐shaped wall thickenings lining the ventral suture are instrumental in explosive fruitlet dehiscence. Generally, the fruit structure of Illicium differs dramatically from those in other early diverging angiosperms. Gynoecium and fruit structure (and a probable early Cretaceous divergence from the Schisandra‐Kadsura clade) provide evidence for treatment of Illicium as separate from Schisandraceae s.s. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013 , 171 , 640–654.     

Reproductive responses to photoperiod and temperature by diapausing and nondiapausing populations of Sesamia nonagrioides Lef. (Lepidoptera − Noctuidae)

Abstract.  The influence of long- and short-day cycles on ovipostion and egg hatch of the corn stalk borer, Sesamia nonagrioides were investigated at a range of temperatures. Oviposition was suppressed when insects are exposed to long days through their immature stages and then transferred to short days after mating. Moreover, mean oviposition and egg hatch increased from 15 to 27.5 °C, whereas oviposition declined significantly at 30 °C at both photoperiodic regimes. Females derived from a diapausing population exposed to long days after mating showed a significantly higher egg production compared to females derived from a nondiapausing population. However, when females from a diapausing population were left to oviposit under short days, fewer eggs were produced compared to those exposed to long days after mating. Thus, photoperiod appears to affect reproductive traits of this species in a quantitative manner. Larval diapause duration is positively correlated with fecundity of the adults. There is also a positive correlation between pupal weight of individuals derived from a diapausing population and the postdiapause fecundity of adults.     

Phylogeny of Psephenidae (Coleoptera: Byrrhoidea) based on larval, pupal and adult characters

Abstract.  We conducted the first comprehensive phylogenetic analysis of Psephenidae, based on 143 morphological characters of adults, larvae and pupae and coded for 34 taxa, representing three outgroups and 31 psephenid genera, including four undescribed ones. A strict consensus tree calculated (439 steps, consistency index = 0.45, retention index = 0.75) from the two most-parsimonious cladograms indicated that the monophyly of the family and subfamilies is supported, with the exception of Eubriinae, which is paraphyletic when including Afroeubria . Here a new subfamily, Afroeubriinae ( subfam.n. ), is formally established for Afroeubria . The analysis also indicated that the 'streamlined' larva is a derived adaptive radiation. Here, suprageneric taxonomy and the evolution of some significant characters are discussed. Keys are provided to the subfamilies and genera of Psephenidae considering larvae, adults and pupae.     

C-Jun N-terminal kinase controls TDP-43 accumulation in stress granules induced by oxidative stress

Background

TDP-43 proteinopathies are characterized by loss of nuclear TDP-43 expression and formation of C-terminal TDP-43 fragmentation and accumulation in the cytoplasm. Recent studies have shown that TDP-43 can accumulate in RNA stress granules (SGs) in response to cell stresses and this could be associated with subsequent formation of TDP-43 ubiquinated protein aggregates. However, the initial mechanisms controlling endogenous TDP-43 accumulation in SGs during chronic disease are not understood. In this study we investigated the mechanism of TDP-43 processing and accumulation in SGs in SH-SY5Y neuronal-like cells exposed to chronic oxidative stress. Cell cultures were treated overnight with the mitochondrial inhibitor paraquat and examined for TDP-43 and SG processing.

Results

We found that mild stress induced by paraquat led to formation of TDP-43 and HuR-positive SGs, a proportion of which were ubiquitinated. The co-localization of TDP-43 with SGs could be fully prevented by inhibition of c-Jun N-terminal kinase (JNK). JNK inhibition did not prevent formation of HuR-positive SGs and did not prevent diffuse TDP-43 accumulation in the cytosol. In contrast, ERK or p38 inhibition prevented formation of both TDP-43 and HuR-positive SGs. JNK inhibition also inhibited TDP-43 SG localization in cells acutely treated with sodium arsenite and reduced the number of aggregates per cell in cultures transfected with C-terminal TDP-43 162-414 and 219-414 constructs.

Conclusions

Our studies are the first to demonstrate a critical role for kinase control of TDP-43 accumulation in SGs and may have important implications for development of treatments for FTD and ALS, targeting cell signal pathway control of TDP-43 aggregation.     

Defunct brain stem cardiovascular regulation underlies cardiovascular collapse associated with methamphetamine intoxication

Background  

Intoxication from the psychostimulant methamphetamine (METH) because of cardiovascular collapse is a common cause of death within the abuse population. For obvious reasons, the heart has been taken as the primary target for this METH-induced toxicity. The demonstration that failure of brain stem cardiovascular regulation, rather than the heart, holds the key to cardiovascular collapse induced by the pesticide mevinphos implicates another potential underlying mechanism. The present study evaluated the hypothesis that METH effects acute cardiovascular depression by dampening the functional integrity of baroreflex via an action on brain stem nuclei that are associated with this homeostatic mechanism.     

A portable system for collecting anatomical joint angles during stair ascent: a comparison with an optical tracking device

Background

Assessments of stair climbing in real-life situations using an optical tracking system are lacking, as it is difficult to adapt the system for use in and around full flights of stairs. Alternatively, a portable system that consists of inertial measurement units (IMUs) can be used to collect anatomical joint angles during stair ascent. The purpose of this study was to compare the anatomical joint angles obtained by IMUs to those calculated from position data of an optical tracking device.

Methods

Anatomical joint angles of the thigh, knee and ankle, obtained using IMUs and an optical tracking device, were compared for fourteen healthy subjects. Joint kinematics obtained with the two measurement devices were evaluated by calculating the root mean square error (RMSE) and by calculating a two-tailed Pearson product-moment correlation coefficient (r) between the two signals.

Results

Strong mean correlations (range 0.93 to 0.99) were found for the angles between the two measurement devices, as well as an average root mean square error (RMSE) of 4 degrees over all the joint angles, showing that the IMUs are a satisfactory system for measuring anatomical joint angles.

Conclusion

These highly portable body-worn inertial sensors can be used by clinicians and researchers alike, to accurately collect data during stair climbing in complex real-life situations.

     

DIFFERENTIAL ANTHERIDIOGEN RESPONSE AND EVOLUTIONARY MECHANISMS IN CYSTOPTERIS

It has been demonstrated that antheridiogens determine gametangial initiation in cultures of some homosporous fern gametophytes. Studies of natural populations have implicated these compounds as breeding system controllers. In Cystopteris, response to antheridiogen varied significantly among species. While Cystopteris protrusa responded to exogenous antheridiogen, C. bulbifera did not. The allopolyploid derivative of these two species, C. tennesseensis, had an intermediate level of response. This marked physiological difference among morphologically similar taxa is valuable in delineating species and suggests a mechanism that may be associated with interspecific hybridization.     

Molecular phylogenetics and evolution of the endemic Hawaiian genus Adenophorus (Grammitidaceae)

Recent studies of the phylogeny of several groups of native Hawaiian vascular plants have led to significant insights into the origin and evolution of important elements of the Hawaiian flora. No groups of Hawaiian pteridophytes have been subjected previously to rigorous phylogenetic analysis. We conducted a molecular phylogenetic analysis of the endemic Hawaiian fern genus Adenophorus employing DNA sequence variation from three cpDNA fragments: rbcL, atpbeta, and the trnL-trnF intergenic spacer (IGS). In the phylogenetic analyses we employed maximum parsimony and Bayesian inference. Bayesian phylogenetic inference often provided stronger support for hypothetical relationships than did nonparametric bootstrap analyses. Although phylogenetic analyses of individual DNA fragments resulted in different patterns of relationships among species and varying levels of support for various clades, a combined analysis of all three sets of sequences produced one, strongly supported phylogenetic hypothesis. The primary features of that hypothesis are: (1) Adenophorus is monophyletic; (2) subgenus Oligadenus is paraphyletic; (3) the enigmatic endemic Hawaiian species Grammitis tenella is strongly supported as the sister taxon to Adenophorus; (4) highly divided leaf blades are evolutionarily derived in the group and simple leaves are ancestral; and, (5) the biogeographical origin of the common ancestor of the Adenophorus-G. tenella clade remains unresolved, although a neotropical origin seems most likely.     

CHROMOSOMAL ANALYSES AND THE ORIGIN OF ALLOPOLYPLOID POLYPODIUM VIRGINIANUM (POLYPODIACEAE)

Polypodium virginianum L. has been treated as a morphologically and chromosomally variable species. Recently, however, two species have been named from within the P. virginianum complex. Chromosome counts reported here confirmed that these segregate species, P. appalachianum Haufler and Windham and P. sibiricum Siplivinskij, are diploids with n = 37. It was further hypothesized that hybridization between these diploids initiated the allotetraploid P. virginianum. Naturally occurring, sterile triploid plants obtained from habitats in which the putative allotetraploid was sympatric with its presumed diploid progenitors have been verified isozymically as backcross hybrids. Meiotic chromosomal behavior showed that the triploids contained univalents and bivalents in nearly equal numbers, confirming that tetraploid P. virginianum contained one genome from each diploid. Observation of three to six trivalents in triploid preparations suggested that the diploids are still closely related genetically. This hypothesis was supported by isozymic studies which found a genetic identity of 0.610 between P. appalachianum and P. sibiricum, a value much higher than the average identity for congeneric fern species studied to date (0.33) and higher than any other species pair in the P. vulgare L. complex (average I = 0.307). These chromosomal and isozymic data help to resolve a biosystematic riddle that has interested pteridologists for over 40 years.