Centrosomes: Central no more?

It has recently been found that the zygotic development of a morphologically normal fly can occur without properly functioning mitotic centrosomes. Does this mean that centrosomes are not required for cell division in animals at all?     

Aliens or natives: who are the ‘thugs’ in British woods?

The invasion of native habitats by exotic, or alien, plant species has received considerable attention recently from policy, research, and practical conservation management perspectives. However, a new hypothesis for species dynamics in Britain suggests that a small number of aggressive native plant species (termed ‘thugs’) may have an equal, or greater, impact on native species and habitats than exotic species. Here, we examine this hypothesis using multivariate techniques with field-layer cover data collected during a country-wide survey of British woodlands. Multivariate analysis of these data identified a north-south gradient on the first axis, and that 20 of the 25 National Vegetation Classification woodland types were sampled within the study. The most abundant field-layer species included three of the proposed native ‘thugs’, i.e. Rubus fruticosus, Pteridium aquilinum and Hedera helix in addition to the native woodland indicator species Mercurialis perennis. Variation partitioning was used to compare the relative importance of native field-layer ‘thug’ species with invading alien shrub and tree species relative to other environmental drivers. The variation in the field-layer data-set explained by the three native ‘thug’ species was significant, but they explained a relatively small proportion of the variation relative to other environmental variables (climate, soil, management factors etc.). They did, however, explain almost four times as much variation as the three alien species that were significantly correlated with field-layer species composition (Acer pseudoplatanus, Impatiens glandulifera, Rhododendron ponticum). The results of this analysis suggest that the field-layer of British woodlands is impacted as much by native ‘thug’ species, as it is from ‘aliens’. Concern about the impact of these native ‘thug’ species has been reported previously, but their impact has not previously been compared to the impact of invading aliens. It is hoped that this analysis will do two things, first to act as a sound baseline for assessing any changing balance that should occur in the future, and second, to prompt both ecologists and conservationists to develop woodland management policies based on sound science.     

Fertility intentions and subsequent fertility behaviour in Matlab: do fertility intentions matter?

This study examines the extent of the interrelationship between future fertility intention and subsequent fertility behaviour in rural Bangladesh using longitudinal data. It confirms that fertility intention is an important predictor of subsequent fertility behaviour for rural Bangladeshi women. Women wanting no more children are over three times less likely to have a child during a 5-year follow-up than those wanting more children. A multivariate model using logistic regression shows that fertility intention is a useful indicator for fertility behaviour, when background and life-cycle variables are controlled. The different patterns of fertility intentions by socioeconomic and demographic subgroups suggest that different programme strategies should be designed for specific target groups.     

Elemental composition and degree of homeostasis of fungi: are aquatic hyphomycetes more like metazoans,bacteria or plants?

Ecological stoichiometry generally assumes that heterotrophs have a higher degree of elemental homeostasis than autotrophs. Differences between fixed consumer nutrient requirements and nutrients available in resources allow prediction of the intensity of nutrient recycling ensured by heterotrophs. Despite their fundamental role in detritus decomposition, extremely few data are currently available on fungal elemental composition. In this study, we quantified the degree of elemental homeostasis of aquatic hyphomycetes used as model organisms. Contrary to metazoans, but similar to plants, aquatic hyphomycetes exhibited highly plastic elemental compositions. Mycelium also reached far higher C/nutrient ratios than reported for bacteria. Our results suggest that non-homeostasis of fungi should be explicitly included in stoichiometric models dealing with nutrient recycling, and that the discrepancy in homeostasis between some bacterial strains and fungi should certainly be considered when investigating interactions between both groups of decomposers.     

Dissecting the PCP pathway: One or more pathways?

Planar cell polarity (PCP), the alignment of cells within 2D tissue planes, involves a set of core molecular regulators highly conserved between animals and cell types. These include the transmembrane proteins Frizzled (Fz) and VanGogh and the cytoplasmic regulators Dishevelled (Dsh) and Prickle. It is widely accepted that this core forms part of a 'PCP pathway' for signal transduction, which can affect cell morphology through activation of an evolutionary ancient regulatory module involving Rho family GTPases and Myosin II, and/or the JNK kinase cascade. We have re-examined the evidence for interactions between the proposed PCP pathway components, and question the placing of the cell morphology regulators in the same pathway as the PCP core. While Fz and Dsh are clearly involved in both PCP and Rho-based cell morphology regulation, available evidence cannot currently discriminate whether these processes are linked mechanistically by a shared Fz/Dsh population, or pass by two distinct pathways.     

Does the computer act like the braine, or like any biological cell?

A new conception of computer functioning is proposed, which suggests that a computer is a reactor in which a unique enzymic reaction at a single operation mode occurs. The analogy between informatics and enzymology is considered. In the context of the parallelism proposed, the work of the brain is analogous to the work of a global computer network. Not the brain as a network of neuron processors but a network of computers as the brain!     

The politics of fear: what does it mean to those who are otherized and feared?

Islamophobia has, of late, created a tendency to conflate all Muslims as belonging to a single nation of Islam that does not recognize and respect boundaries imposed by western geopolitics. This has been done by some to create and by others to generate a sense of exclusive unity that would separate all Muslims and make them into ‘others’ within western societies. It is the contention of this paper that such calls both embody and ignore the diversities of Islam as understood and practised by its adherents. Furthermore by ‘otherizing’ the entire community of Muslims in the West, the singular label of ‘Islamism’ marginalizes and may even silence the vibrant contestations among Muslims about their faith and its teachings; these include questions posed by women who may be described as feminists. The attributes of Islamism, ascribed to the faith by public, the media and politicians in the West and adopted by some Muslims primarily as a politically unifying force, are very different from the fluidity and flexibility that has been a historic part of lived Islam. Many Muslims may well aspire to belong to the umma: people of Islam conceptualized as crossing ethnic, racial, geographical and political boundaries. But Muslims in general and Muslim women in particular do not wish to do so at the expense of being otherized and conforming to the negative stereotypes ascribed to them that mask their fluid identities and, in the case of ‘white’ women, their close ties with their kinship networks. The multiplicity of Muslim's identities sits more easily within the permeable unbounded umma applicable to the global as well as the local without necessarily always privileging one or other identity.     

A practical question based on cross-platform microarray data normalization: are BOEC more like large vessel or microvascular endothelial cells or neither of them?

Since the available microarray data of BOEC (human blood outgrowth endothelial cells), large vessel, and microvascular endothelial cells were from two different platforms, a working cross-platform normalization method was needed to make these data comparable. With six HUVEC (human umbilical vein endothelial cells) samples hybridized on two-channel cDNA arrays and six HUVEC samples on Affymetrix arrays, 64 possible combinations of a three-step normalization procedure were investigated to search for the best normalization method, which was selected, based on two criteria measuring the extent to which expression profiles of biological samples of the same cell type arrayed on two platforms were indistinguishable. Next, three discriminative gene lists between the large vessel and the microvascular endothelial cells were achieved by SAM (significant analysis of microarrays), PAM (prediction analysis for microarrays), and a combination of SAM and PAM lists. The final discriminative gene list was selected by SVM (support vector machine). Based on this discriminative gene list, SVM classification analysis with best tuning parameters and 10,000 times of validations showed that BOEC were far from large vessel cells, they either formed their own class, or fell into the microvascular class. Based on all the common genes between the two platforms, SVM analysis further confirmed this conclusion.     

Does it matter who pulls the switch? Perceptions of intentions in the trolley dilemma

This research examines the automatic moral and intentional inferences that third parties generate as a function of outcomes for the actor. Participants were asked about the moral acceptability of redirecting a train to save five lives by sacrificing one, as well as the intentions of the person directing the train, and the consequences of doing so. Actor position was varied with respect to whether the person redirecting the train stood to benefit by doing so. Across four studies in international and US samples, participants rated the redirection as less morally acceptable or more punishable when the actor redirecting the train was saving their own life in the process. The implications of these findings for moral claims are discussed.     

Inhibitors of c-Jun N-terminal kinases: JuNK no more?

The c-Jun N-terminal kinases (JNKs) have been the subject of intense interest since their discovery in the early 1990s. Major research programs have been directed to the screening and/or design of JNK-selective inhibitors and testing their potential as drugs. We begin this review by considering the first commercially-available JNK ATP-competitive inhibitor, SP600125. We focus on recent studies that have evaluated the actions of SP600125 in lung, brain, kidney and liver following exposure to a range of stress insults including ischemia/reperfusion. In many but not all cases, SP600125 administration has proved beneficial. JNK activation can also follow infection, and we next consider recent examples that demonstrate the benefits of SP600125 administration in viral infection. Additional ATP-competitive JNK inhibitors have now been described following high throughput screening of small molecule libraries, but information on their use in biological systems remains limited and thus these inhibitors will require further evaluation. Peptide substrate-competitive ATP-non-competitive inhibitors of JNK have also now been described, and we discuss the recent advances in the use of JNK inhibitory peptides in the treatment of neuronal death, diabetes and viral infection. We conclude by raising a number of questions that should be considered in the quest for JNK-specific inhibitors.