7,275 research outputs found
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
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
Black Cutworm Scouting Advisory
With the unseasonably warm temperatures occurring earlier this year, we asked black cutworm monitoring participants to place moth traps during the end of March. The first moth was recorded in Muscatine County on March 20. Peak flights have been reported by cooperators in many parts of Iowa this year. Our predictions of cutting dates (the date when black cutworm larvae are likely to be damaging corn) are based on recorded peak flights which took place near the end of March and approximately two weeks later in Iowa. The map (Fig. 1) shows the predicted cutting dates for Iowa climate divisions. Where there are two dates, the top date is an estimate based on moth captures that occurred near the end of March; all other dates are based on mid-April captures
Incidence of multiple primary cancers in a cohort of women diagnosed with breast cancer in southeast England
Among women in the Thames Cancer Registry database with a first breast cancer diagnosed between 1961–1995 observed numbers of subsequent cancers were compared with expected numbers and standardized incidence ratios were calculated. The occurrence of breast cancers subsequent to cancers at other sites was also examined. Women diagnosed with breast cancer before age 50 had significantly elevated risks for 9 cancer sites namely, oesophagus, stomach, lung, bone, connective tissue, breast, corpus uteri, ovary and myeloid leukaemia compared with 2 sites (corpus uteri and myeloid leukaemia) in women diagnosed at age 50 and above. Some of these associations are consistent with the effects of known inherited cancer susceptibility genes, shared environmental factors, or therapy. © 2001 Cancer Research Campaign http://www.bjcancer.co
Genotype reconstruction of paternity in European lobsters (Homarus gammarus)
This is the author accepted manuscript. The final version is available on open access from Public Library of Science via the DOI in this recordData Availability: Microsatellite genotypes of 312 individuals (13 spatial samples of 24 individuals), used in the calculation of regional allele frequencies, microsatellite characterisation, and tests of HWE, linkage and null alleles, are available on the Dryad Digital Repository at http://dx.doi.org/10.5061/dryad.v176mDecapod crustaceans exhibit considerable variation in fertilisation strategies, ranging from pervasive single paternity to the near-ubiquitous presence of multiple paternity, and such knowledge of mating systems and behaviour are required for the informed management of commercially-exploited marine fisheries. We used genetic markers to assess the paternity of individual broods in the European lobster, Homarus gammarus, a species for which paternity structure is unknown. Using 13 multiplexed microsatellite loci, three of which are newly described in this study, we genotyped 10 eggs from each of 34 females collected from an Atlantic peninsula in the south-western United Kingdom. Single reconstructed paternal genotypes explained all observed progeny genotypes in each of the 34 egg clutches, and each clutch was fertilised by a different male. Simulations indicated that the probability of detecting multiple paternity was in excess of 95% if secondary sires account for at least a quarter of the brood, and in excess of 99% where additional sire success was approximately equal. Our results show that multiple paternal fertilisations are either absent, unusual, or highly skewed in favour of a single male among H. gammarus in this area. Potential mechanisms upholding single paternal fertilisation are discussed, along with the prospective utility of parentage assignments in evaluations of hatchery stocking and other fishery conservation approaches in light of this finding.European Social FundFisheries Charitable Trust of the Fishmongers' Company, U
Reconstructing the global topology of the universe from the cosmic microwave background
If the universe is multiply-connected and sufficiently small, then the last
scattering surface wraps around the universe and intersects itself. Each circle
of intersection appears as two distinct circles on the microwave sky. The
present article shows how to use the matched circles to explicitly reconstruct
the global topology of space.Comment: 6 pages, 2 figures, IOP format. To be published in the proceedings of
the Cleveland Cosmology and Topology Workshop 17-19 Oct 1997. Submitted to
Class. Quant. Gra
Spherical structures on torus knots and links
The present paper considers two infinite families of cone-manifolds endowed
with spherical metric. The singular strata is either the torus knot or the torus link . Domains of existence for a
spherical metric are found in terms of cone angles and volume formul{\ae} are
presented.Comment: 17 pages, 5 figures; typo
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