Learning From Early Attempts to Generalize Darwinian Principles to Social Evolution

Copyright University of Hertfordshire & author.Evolutionary psychology places the human psyche in the context of evolution, and addresses the Darwinian processes involved, particularly at the level of genetic evolution. A logically separate and potentially complementary argument is to consider the application of Darwinian principles not only to genes but also to social entities and processes. This idea of extending Darwinian principles was suggested by Darwin himself. Attempts to do this appeared as early as the 1870s and proliferated until the early twentieth century. But such ideas remained dormant in the social sciences from the 1920s until after the Second World War. Some lessons can be learned from this earlier period, particularly concerning the problem of specifying the social units of selection or replication

Mainstreaming prevention: Prescribing fruit and vegetables as a brief intervention in primary care

This is the author's PDF version of an article published in Public health© 2005.This articles discusses a project at the Castlefields Health Centre in Halton whereby primary care professionals issue a prescription for discounts on fruit and vegetables. The prescription is explicitly linked to the five-a-day message

Numerical investigation of high and low pressure tube hydroforming

Hydroforming is one option to reduce vehicle weight while increasing component stiffness and rigidity. This typically involves using a fluid to form a component with high internal pressure. Tube hydroforming has gained increasing interest in the automotive and aerospace industries because of its many advantages such as part consolidation, good quality of the formed part etc. The main advantage is that the uniform pressure can be transferred to whole part at the same time. In low pressure hydroforming, the internal pressure is significantly and the hydroformed section length of line stays almost the same as the circumference of the blank tube. This paper details the comparison between high and low pressure hydroforming. It is shown that the internal pressure and holding force required for low pressure hydroforming process is much less than that of high pressure. Also stress and thickness distribution are more uniform and the process is highly suitable for the forming of advanced high strength steels.<br /

An investigation of complex shapes during low pressure tube hydroforming

Hollow structures made of Advanced High Strength Steel (AHSS) are increasingly used in the automobile industry for crash and structural components. Generally high pressure hydroforming is used to form these tabular parts, which is a costly manufacturing process due to the high pressure equipment and large tonnage presses required. A new process termed low pressure hydroforming, where a pressurized tube is crushed between two dies, represents a more cost effective alternative due to the lower pressures and die closing forces required.In this study the low pressure tube hydroforming of one simple and two different complex hollow shapes is investigated. The complexities of the pat1S compared to simple shapes are critically studied and the die filling conditions are investigated and discussed. FUl1hennore the thickness distributions over the circumference of the part during forming are analyzed.<br /

Abnormal negative feedback processing in first episode schizophrenia: evidence from an oculomotor rule switching task

Background. Previous studies have shown that patients with schizophrenia are impaired on executive tasks, where positive and negative feedbacks are used to update task rules or switch attention. However, research to date using saccadic tasks has not revealed clear deficits in task switching in these patients. The present study used an oculomotor ‘ rule switching ’ task to investigate the use of negative feedback when switching between task rules in people with schizophrenia. Method. A total of 50 patients with first episode schizophrenia and 25 healthy controls performed a task in which the association between a centrally presented visual cue and the direction of a saccade could change from trial to trial. Rule changes were heralded by an unexpected negative feedback, indicating that the cue-response mapping had reversed. Results. Schizophrenia patients were found to make increased errors following a rule switch, but these were almost entirely the result of executing saccades away from the location at which the negative feedback had been presented on the preceding trial. This impairment in negative feedback processing was independent of IQ. Conclusions. The results not only confirm the existence of a basic deficit in stimulus–response rule switching in schizophrenia, but also suggest that this arises from aberrant processing of response outcomes, resulting in a failure to appropriately update rules. The findings are discussed in the context of neurological and pharmacological abnormalities in the conditions that may disrupt prediction error signalling in schizophrenia

The role of the dominant versus the non-dominant hemisphere: an fMRI study of Aphasia recovery following stroke

Background: Speech production is one of the most frequently affected cognitive functions following stroke; however, the neural mechanisms underlying the recovery of speech function are still incompletely understood. Aims: The current study aims to address the differential contributions of the dominant and non-dominant hemispheres in recovery from aphasia following stroke by comparing data from four stroke patients and 12 control participants to assess the patterns of activation during speech production tasks during functional magnetic resonance imaging (fMRI) scanning. Methods & Procedures: Four chronic stroke patients (three left-hemisphere lesion and one right-hemisphere lesion) diagnosed with Broca’s aphasia at the acute phase, but now recovered to near normal speech ability, were tested on speech production tasks (phonemic fluency, categorical fluency and picture naming) whilst undergoing fMRI. These patients were compared with 12 healthy controls undergoing the same procedure. Outcomes & Results: Individual subject analysis showed activation peaks in perilesional areas in three out of four patients. This included one patient with right-hemisphere lesion, who also showed predominant perilesional activation. Group analysis of control participants showed predominately left-hemisphere activation, but not exclusively so. Laterality indexes were calculated and showed predominant left-hemisphere lateralisation in the control group (LI = 0.4). Three out of the four patients showed speech lateralised to the same hemisphere as their lesion and the fourth patient showed speech lateralised to the opposite hemisphere to their lesion. Different speech production tasks resulted in varying lateralisation indices (LIs) within participants. Conclusions: The data suggest that perilesional areas support recovery of speech in the chronic phase post-stroke regardless of the site of the lesion. The study has implications for the understanding of functional recovery as well as for the paradigms used in fMRI to localise speech production areas. Specifically, a variety of speech tasks are required to elicit activation that is representative of the range of cortical involvement in speech in healthy adults and that also allows for accurate reporting of the extent of recovery experienced in patients

A trait-based approach for predicting species responses to environmental change from sparse data : how well might terrestrial mammals track climate change?

Acknowledgements LS was supported by two STSMs by the COST Action ES1101 ”Harmonising Global Biodiversity Modelling“ (Harmbio), supported by COST (European Cooperation in Science and Technology). JMB and SMW were funded by CEH projects NEC05264 and NEC05100. JMJT and SCFP are grateful for the support of the Natural Environment Research Council UK (NE/J008001/1). LS, JAH and JMJT conceived the original idea. LS, JAH, JMB, TC & JMJT designed the study; LS collected the data; LS and TC performed the statistical analyses; LS conducted the integrodifference modelling assisted by JMB and SMW. LS conducted the individual-based modelling assisted by SCFP. LS led the writing supported by JMJT, JMB, SCFP, SMW, TC, JAH and GB.Peer reviewedPublisher PD