Seasonal 'fall out' of sessile macro-fauna from submarine cliffs: quantification, causes and implications

Submarine cliffs are typically crowded with sessile organisms, most of which are ultimately exported downwards. Here we report a 24 month study of benthic fauna dropping from such cliffs at sites of differing cliff angle and flow rates at Lough Hyne Marine Nature Reserve, Co. Cork, Ireland. The magnitude of 'fall out' material collected in capture nets was highly seasonal and composed of sessile and mobile elements. Sponges, ascidians, cnidarians, polychaetes, bryozoans and barnacles dominated the sessile forms. The remainder (mobile fauna) were scavengers and predators such as asteroid echinoderms, gastropod molluscs and malacostracan crustaceans. These were probably migrants targeting fallen sessile organisms. 'Fall out' material (including mobile forms) increased between May and August in both years. This increase in 'fall out' material was correlated with wrasse abundance at the cliffs (with a one month lag period). The activities of the wrasse on the cliffs (feeding, nest building and territory defence) were considered responsible for the majority of 'fall out' material, with natural mortality and the activity of other large mobile organisms (e.g. crustaceans) also being triplicated. Current flow rate and cliff profile were important in amount of 'fall out' material collected. In low current situations export of fallen material was vertical, while both horizontal and vertical export was associated with moderate to high current environments. Higher 'fall out' was associated with overhanging than vertical cliff surfaces. The 'fall out' of marine organisms in low current situations is likely to provide ail important source of nutrition in close proximity to the cliff, in an otherwise impoverished soft sediment habitat. However, in high current areas material will be exported some distance from the source, with final settlement again occurring in soft sediment habitats (as current speed decreases).

Optokinetic stimulation induces illusory movement of both out-of-the-body and on-the-body hand-held visual objects

The coding of body part location may depend upon both visual and proprioceptive information, and allows targets to be localized with respect to the body. The present study investigates the interaction between visual and proprioceptive localization systems under conditions of multisensory conflict induced by optokinetic stimulation (OKS). Healthy subjects were asked to estimate the apparent motion speed of a visual target (LED) that could be located either in the extrapersonal space (visual encoding only, V), or at the same distance, but stuck on the subject's right index finger-tip (visual and proprioceptive encoding, V-P). Additionally, the multisensory condition was performed with the index finger kept in position both passively (V-P passive) and actively (V-P active). Results showed that the visual stimulus was always perceived to move, irrespective of its out- or on-the-body location. Moreover, this apparent motion speed varied consistently with the speed of the moving OKS background in all conditions. Surprisingly, no differences were found between V-P active and V-P passive conditions in the speed of apparent motion. The persistence of the visual illusion during the active posture maintenance reveals a novel condition in which vision totally dominates over proprioceptive information, suggesting that the hand-held visual stimulus was perceived as a purely visual, external object despite its contact with the hand.

The effect of farming system and fertilisers on pests and natural enemies: A synthesis of current research

Organic agriculture is becoming widespread due to increased consumer demand and regulatory and political support. Organic agriculture can increase arthropod diversity but the response of pests and their natural enemies is variable. Fertiliser is an important component of agricultural systems and its effects on pests and natural enemies will influence agroecosystems. In this study, meta-analysis and vote-counting techniques were used to compare farming system (organic and conventional) and fertiliser effects on arthropod pests and their natural enemies. The meta-analyses indicated that pests generally benefitted from organic techniques, this is particularly evident when experiments were carried out on a smaller scale. Pest responses to organic and conventional fertiliser types were divergent, plant composts benefitted pest arthropods while the opposite was true for manures, this has implications for pest management. Most natural enemy groups responded positively to organic farming although this was not true for Coleopterans. Experimental scale had a prominent impact on natural enemy responses with farm scale studies showing particularly positive effects of organic agriculture on natural enemies. This suggests that it is large scale features of organic agriculture such as landscape heterogeneity that are beneficial to natural enemies. Natural enemy responses to organic fertilisers were positive indicating that field scale management practices including fertiliser can also be important in pest management.

What determines the out-of-home placement of children in the USA?

Using NCANDS data of US child maltreatment reports for 2009, logistic regression, probit analysis, discriminant analysis and an artificial neural network are used to determine the factors which explain the decision to place a child in out-of-home care. As well as developing a new model for 2009, a previous study using 2005 data is replicated. While there are many small differences, the four estimation techniques give broadly the same results, demonstrating the robustness of the results. Similarly, apart from age and sexual abuse, the 2005 and 2009 results are roughly similar. For 2009, child characteristics (particularly child emotional problems) are more important than the nature of the abuse and the situation of the household; while caregiver characteristics are the least important. All these models have low explanatory power.

Epoxide ring opening in a zinc(II) complex in water without any Lewis acid catalyst: formation of only one diastereomer out of 2

The epoxide ring in 5,6-dihydro-5,6-epoxy-1,10-phenanthroline (L) opens up in its reaction with 4-methylaniline and 4-methoxyaniline in water in equimolar proportion at room temperature without any Lewis acid catalyst to give a monohydrate of 6-(4-methyl-phenylamino)-5,6-dihydro-1,10-phenanthrolin-5-ol (L′·H2O) and 6-(4-methoxyphenyl-amino)-5,6-dihydro-1,10-phenanthrolin-5-ol (L″) respectively. Reaction time decreases from 72 to 14 h in boiling water. But the yields become less. Reaction of L with Zn(ClO4)2·6H2O in methanol in 3:1 molar ratio at room temperature affords white [ZnL3](ClO4)2·H2O. The X-ray crystal structure of the acetonitrile solvate [ZnL3](ClO4)2·MeCN has been determined which shows that the metal has a distorted octahedral N6 coordination sphere. [ZnL3](ClO4)2·2H2O reacts with 4-methylaniline and 4-methoxyaniline in boiling water in 1:3 molar proportion in the absence of any Lewis acid catalyst to produce [ZnL′3](ClO4)2·4H2O and [ZnL″3](ClO4)2·H2O, respectively in 1–4 h time in somewhat low yield. In the 1H NMR spectra of [ZnL′3](ClO4)2·4H2O and [ZnL″3](ClO4)2·H2O, only one sharp methyl signal is observed implicating that only one diastereomer out of the 23 possibilities is formed. The same diastereomers are obtained when L′·H2O and L″ are reacted directly with Zn(ClO4)2·6H2O in tetrahydrofuran at room temperature in very good yields. Reactions of L′·H2O and L″ with Ru(phen)2Cl2·2H2O (phen = 1,10-phenanthroline) in equimolar proportion in methanol–water mixture under refluxing condition lead to the isolation of two diastereomers of [Ru(phen)2L′](ClO4)2·2H2O and [Ru(phen)2L″](ClO4)2·2H2O.

Historical and idealized climate model experiments: an intercomparison of Earth system models of intermediate complexity

Both historical and idealized climate model experiments are performed with a variety of Earth system models of intermediate complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE and continue through to 2005. The standard simulations include changes in forcing from solar luminosity, Earth's orbital configuration, CO2, additional greenhouse gases, land use, and sulphate and volcanic aerosols. In spite of very different modelled pre-industrial global surface air temperatures, overall 20th century trends in surface air temperature and carbon uptake are reasonably well simulated when compared to observed trends. Land carbon fluxes show much more variation between models than ocean carbon fluxes, and recent land fluxes appear to be slightly underestimated. It is possible that recent modelled climate trends or climate–carbon feedbacks are overestimated resulting in too much land carbon loss or that carbon uptake due to CO2 and/or nitrogen fertilization is underestimated. Several one thousand year long, idealized, 2 × and 4 × CO2 experiments are used to quantify standard model characteristics, including transient and equilibrium climate sensitivities, and climate–carbon feedbacks. The values from EMICs generally fall within the range given by general circulation models. Seven additional historical simulations, each including a single specified forcing, are used to assess the contributions of different climate forcings to the overall climate and carbon cycle response. The response of surface air temperature is the linear sum of the individual forcings, while the carbon cycle response shows a non-linear interaction between land-use change and CO2 forcings for some models. Finally, the preindustrial portions of the last millennium simulations are used to assess historical model carbon-climate feedbacks. Given the specified forcing, there is a tendency for the EMICs to underestimate the drop in surface air temperature and CO2 between the Medieval Climate Anomaly and the Little Ice Age estimated from palaeoclimate reconstructions. This in turn could be a result of unforced variability within the climate system, uncertainty in the reconstructions of temperature and CO2, errors in the reconstructions of forcing used to drive the models, or the incomplete representation of certain processes within the models. Given the forcing datasets used in this study, the models calculate significant land-use emissions over the pre-industrial period. This implies that land-use emissions might need to be taken into account, when making estimates of climate–carbon feedbacks from palaeoclimate reconstructions.

Dynamical downscaling: Assessment of model system dependent retained and added variability for two different regional climate models

Did they talk their way out of Africa?

Corballis suggests that fully vocal communication was invented by modern humans between 170,000 and 50,000 years ago. Because this new form of communication did not require hand gestures, he wondered whether this may have facilitated the development of lithic manufacture. I cast doubt on this interesting notion but offer an enhanced version that may have more potential.