Concordant phylogeography and cryptic speciation in two Western Palaearctic oak gall parasitoid species complexes

Little is known about the evolutionary history of most complex multi‐trophic insect communities. Widespread species from different trophic levels might evolve in parallel, showing similar spatial patterns and either congruent temporal patterns (Contemporary Host‐tracking) or later divergence in higher trophic levels (Delayed Host‐tracking). Alternatively, host shifts by natural enemies among communities centred on different host resources could disrupt any common community phylogeographic pattern. We examined these alternative models using two Megastigmus parasitoid morphospecies associated with oak cynipid galls sampled throughout their Western Palaearctic distributions. Based on existing host cynipid data, a parallel evolution model predicts that eastern regions of the Western Palaearctic should contain ancestral populations with range expansions across Europe about 1.6 million years ago and deeper species‐level divergence at both 8–9 and 4–5 million years ago. Sequence data from mitochondrial cytochrome b and multiple nuclear genes showed similar phylogenetic patterns and revealed cryptic genetic species within both morphospecies, indicating greater diversity in these communities than previously thought. Phylogeographic divergence was apparent in most cryptic species between relatively stable, diverse, putatively ancestral populations in Asia Minor and the Middle East, and genetically depauperate, rapidly expanding populations in Europe, paralleling patterns in host gallwasp species. Mitochondrial and nuclear data also suggested that Europe may have been colonized multiple times from eastern source populations since the late Miocene. Temporal patterns of lineage divergence were congruent within and across trophic levels, supporting the Contemporary Host‐tracking Hypothesis for community evolution.     

Violent behaviour among people with schizophrenia: a framework for investigations of causes, and effective treatment, and prevention

Robust evidence has accumulated showing that individuals who develop schizophrenia are at elevated risk when compared to the general population to engage in violence towards others. This violence impacts negatively on victims as well as perpetrators and poses a significant financial burden to society. It is posited that among violent offenders with schizophrenia there are three distinct types defined by the age of onset of antisocial and violent behaviour. The early starters display a pattern of antisocial behaviour that emerges in childhood or early adolescence, well before illness onset, and that remains stable across the lifespan. The largest group of violent offenders with schizophrenia show no antisocial behaviour prior to the onset of the illness and then repeatedly engage in aggressive behaviour towards others. A small group of individuals who display a chronic course of schizophrenia show no aggressive behaviour for one or two decades after illness onset and then engage in serious violence, often killing, those who care for them. We hypothesize that both the developmental processes and the proximal factors, such as symptoms of psychosis and drug misuse, associated with violent behaviour differ for the three types of offenders with schizophrenia, as do their needs for treatment.     

Effects of citronella oil (Cymbopogon winterianus Jowitt ex Bor) on Spodoptera frugiperda (J. E. Smith) midgut and fat body

The armyworm, Spodoptera frugiperda, is the principal pest of corn in Brazil. Control is achieved primarily by synthetic insecticides, which cause problems for the agro-ecosystem. Alternative methods of control are under investigation and citronella (Cymbopogon winterianus) essential oil appears to be a promising agent. We investigated the effects of citronella oil using histological, histochemical and immunohistochemical methods. The midgut of larvae treated with citronella exhibited altered epithelium including cytoplasmic protrusions, columnar cell extrusion, pyknotic nuclei, and increased periodic acid-Schiff positive granules. Regenerative cells in the epithelium of the midgut increased in number, which facilitated subsequent regeneration of this tissue. After exposure to citronella, trophocytes, the principal cell type of the fat body, possessed enlarged vacuoles and mitotic bodies, and contained reduced amounts of glycogen, lipid, and protein. Citronella oil caused morphological changes of the midgut and reduction of stored resources in the fat body, which may adversely affect insect reproduction and survival.     

Phylogeography of the marine macroalga Sargassum hemiphyllum (Phaeophyceae,Heterokontophyta) in northwestern Pacific

Sargassum hemiphyllum is commonly found in Japan and Korea, with a variety, var. chinense, that is found distributed in the southern Chinese coast. We previously reported distinct genetic differentiation between the two taxa based on the PCR‐RFLP data of plastid RubiscoL‐S spacer. The present study aims at elucidating the phylogeographic pattern of S. hemiphyllum based on more markers in the nuclear and extranuclear genomes, with a view to reveal the occurrence of hybridization. The two allopatrically distributed taxa were found to be genetically distinct in nuclear ITS2, plastidial Rubisco (Rbc) and mitochondrial TrnW_I (Trn) spacers. Their divergence was postulated to be attributable to the vicariant event which resulted from the isolation of the Sea of Japan during the late Miocene (6.58–11.25 Mya). Divergence within both S. hemiphyllum and the chinense variety was observed based on Trn spacer, while the divergence in S. hemiphyllum was further confirmed in Rbc spacer. This divergence appears to correspond to the separation of the Japanese populations between the Sea of Japan and the Pacific that occurred around 0.92–2.88 Mya (the early Pleistocene). The presence of an ITS2 clone resembling var. chinense sequences in a Japanese population of S. hemiphyllum (JpNS) raises the possibility of the introgression of var. chinense individuals into S. hemiphyllum population. Compared to that between S. hemiphyllum and the chinense variety, hybridization among the Japanese and Korean populations of S. hemiphyllum is highly probable as all these individuals share a pool of nuclear ITS2 sequences, possibly attributable to incomplete concerted evolution of ITS2.     

Isolation of human urinary protease inhibitor by single-step affinity chromatography.

Human urinary protease inhibitor was isolated from freshly collected male urine by a single chromatographic step utilizing bovine α-chymotrypsin (EC 3.4.21.1) covalently bound to cross-linked agarose. The adsorbent was prepared by a new series of chemical reactions using trichloro-s-triazine as coupler. Study of chromatographic parameters, including pH, temperature, and ionic strength, led to a simplified elution system for removing contaminants. The antitryptic-antichymotryptic activity of the inhibitor appeared to be unaltered by chromatography.