Anomalous brain dominance and the immune system: Do left-handers have specific immunological patterns?

Geschwind and Behan (1982) and Geschwind and Galaburda (1985a, 1985b, 1985c) suggested a correlation between brain laterality and immune disorders. To test whether this hypothesis holds true not only for the frequency of immune diseases and circulating autoantibodies, but extends also to cellular immunity, we examined the association between handedness and markers of cellular immunity. Twenty-seven left-handed and 37 right-handed subjects were serologically screened for cellular parameters and 22 left-handed subjects were typed for human leukocyte antigen (HLA). When compared to the right-handers, the left-handed group showed a significant decrease in the inflammatory cell types CD3(+) T cells (total T cells), CD4(+) T cells (T-helper cells), and HLA-Dr (MHC-II, antigen-presenting cells) as well as in the CD19(+) cells (B cells) and CD16/CD57(+) cells (natural killer cells). We assume a relationship exists between cerebral hemispheric specialisation and the immune system not only for humoral but also for cellular immunity, and we discuss the role of the major histocompatibility complex in neurological and immunological development.     

A model of episodic memory: Mental time travel along encoded trajectories using grid cells

The definition of episodic memory includes the concept of mental time travel: the ability to re-experience a previously experienced trajectory through continuous dimensions of space and time, and to recall specific events or stimuli along this trajectory. Lesions of the hippocampus and entorhinal cortex impair human episodic memory function and impair rat performance in tasks that could be solved by retrieval of trajectories. Recent physiological data suggests a novel model for encoding and retrieval of trajectories, and for associating specific stimuli with specific positions along the trajectory. During encoding in the model, external input drives the activity of head direction cells. Entorhinal grid cells integrate the head direction input to update an internal representation of location, and drive hippocampal place cells. Trajectories are encoded by Hebbian modification of excitatory synaptic connections between hippocampal place cells and head direction cells driven by external action. Associations are also formed between hippocampal cells and sensory stimuli. During retrieval, a sensory input cue activates hippocampal cells that drive head direction activity via previously modified synapses. Persistent spiking of head direction cells maintains the direction and speed of the action, updating the activity of entorhinal grid cells that thereby further update place cell activity. Additional cells, termed arc length cells, provide coding of trajectory segments based on the one-dimensional arc length from the context of prior actions or states, overcoming ambiguity where the overlap of trajectory segments causes multiple head directions to be associated with one place. These mechanisms allow retrieval of complex, self-crossing trajectories as continuous curves through space and time.     

Human embryonic stem cell research and the discarded embryo argument

Many who believe that human embryos have moral status are convinced that their use in human embryonic stem cell (hESC) research can be morally justified as long as they are discarded embryos left over from fertility treatments. This is one reason why this view about discarded embryos has played such a prominent role in the debate over publicly funding hESC research in the United States and other countries. Many believe that this view offers the best chance of a compromise between the different sides in this debate. This paper focuses on what seems to be the most plausible argument for this view about discarded embryos. It shows that this argument is unsound regardless of how one understands the claim that embryos have moral status. It also discusses the implications of this conclusion for attempts to use this argument as a basis for public policy.

Bayesian journey-to-crime modelling of juvenile and adult offenders by gender in Manchester

This study tested the Bayesian journey-to-crime (JTC) model by gender and age for serial offenders from Manchester, England. The data were 4056 crimes committed by 171 serial offenders between 2003 and 2006. The data were subdivided by gender and age group to examine whether accuracy and precision varied by these subgroups. In general, the centre of minimum distance was found to be the most accurate measure, but the Bayesian risk and product measures were found to be the most precise measurements. The traditional ‘distance decay’ type of JTC function did not produce estimates that are as accurate nor as precise as the Bayesian approach. Tests were conducted on whether specific gender and age group JTC functions and origin–destination matrices improved predictability. With the exception of juvenile male offenders, the general functions were more accurate and precise. In terms of building an accurate and precise geographical profiling methodology, the results point to the need to include information on the likely predisposition of neighbourhoods to produce offenders as well as information on the crime opportunities available to offenders. Copyright © 2009 John Wiley & Sons, Ltd.     

Young adults with severe congenital hypothyroidism: cognitive event related potentials (ERPs) and the significance of an early start of thyroxine treatment

Congenital hypothyroidism (CH) has devastating effects upon brain development if left untreated. Despite early start of thyroxine treatment, patients still show subtle cognitive deficits compared to controls. We aimed to study auditory event related potentials (ERPs) in young CH adults (N = 12) to verify previous reports of normal attention functions measured by P3 in CH children. We also include ERP components (P1, N1, P2) allowing assessment of a wider range of auditory processing functions. No significant change in P3 latency or amplitude was found in the CH group, but a more subtle change in amplitude topography. A later start of thyroxine treatment was related to increased P3 latency and reduced amplitude. Group differences were found in early ERP components tapping sensory processing, sensory gating and selective attention. The results suggest persisting abnormalities in auditory processing and selective attention that may have influenced cognitive development.     

Freirean Philosophy and Pedagogy in the Adult Education Context: The Case of Older Adults’ Learning

Central tenets of Freirean philosophy and pedagogy are explored and applied to the emerging field of older adults’ learning (educational gerontology), a sub-field of adult education. I argue that many of Freire’s concepts and principles have direct applicability to the tasks of adult educators working alongside marginalized older adults. In particular, Freire’s ideas fit comfortably within a critical educational gerontology approach as they challenge prevailing orthodoxies and provide a robust analytical framework from which radical adult educators can work effectively in promoting social transformation.

Choices in Life: A Clinical Tool for Facilitating Midlife Review

A critical developmental task of midlife involves reviewing one's past as well as preparing for one's future. The ability to identify past choices, task responsibility for them, and utilize developing patterns in future decision making is seen as a critical component of continued adult development. The Choicemap offers a structured clinical tool to guide such a midlife review. Engaging in this process assists adults in developing choicemaking skills, and provides a powerful clinical intervention.     

人类胚胎的道德地位

胚胎干细胞技术的发展带来了干细胞来源的伦理争论,提出了如何看待"胚胎道德地位"的问题。围绕这一问题,有三种观点,它们分别从生物性、理性功能以及人的潜能性来界定胚胎的道德地位。通过对三种观点的分析,本文强调坚持人的尊严原则,是推动新兴生物技术发展的核心和归宿。     

成体干细胞可塑性研究中的若干哲学思考

随着干细胞生物学研究的不断深入,成体干细胞被发现可以分化成组织来源与其无关的其他系统的细胞,即成体干细胞的可塑性.但是最近不断有学者对其提出质疑,认为可塑性可能是与"细胞融合"或成年组织中的"多潜能成年祖细胞"有关.面对可塑性上两种截然相反的观点,我们在热切关注其研究进展的同时,也引发了一连串的哲学思考.     

Self-control in adult humans: variation in positive reinforcer amount and delay.

In five experiments, choice responding of female human adults was examined, as a function of variations in reinforcer amount and reinforcer delay. Experiment 1 used a discrete-trials procedure, and Experiments 2, 3, 4, and 5 used a concurrent variable-interval variable-interval schedule. Reinforcer amount and reinforcer delay were varied both separately and together. In contrast to results previously reported with pigeons, the subjects in the present experiments usually chose the larger reinforcers even when those reinforcers were delayed. Together, the results from all the experiments suggest that the subjects followed a maximization strategy in choosing reinforcers. Such behavior makes it easy to observe self-control and difficult to observe impulsiveness in traditional laboratory experiments that use adult human subjects.