Role of Human Parietal and Premotor Cortical Areas in Complex Hand Movements

The need to understand our ability to plan and successfully execute movement is a core aspect of clinical neurophysiology. Studies in humans are particularly valuable and can have direct application to neurological disorders. While most studies have focused on the physiological characteristics of relatively simple movements (e.g., finger flexion, extension), the aim of the current studies is to determine the mechanisms involved in producing meaningful, complex movements that better represent natural movements. Electroencephalography (EEG) measures such as movement-related cortical potentials, coherence, and event-related synchronization and desynchronization allow investigators to determine the functions of specific areas and coherent networks before and during movement. Patients with ideomotor apraxia, who produce abnormal movements with spatial and/or temporal errors during pantomime of praxis movements (e.g., using a hammer, waving good-bye), were compared to normal subjects. It is our hypothesis that performance of complex movements involves early preparatory activity seen localized in the left parietal and premotor cortical areas. Additionally, we hypothesize that the activity seen in the parietal and premotor cortices is coherent and part of a functional network for such movements. Stroke patients with parietal and premotor lesions with apraxia will show a decrease in function of these areas, as well as reduced communication of the network as a result of their anatomical damage. Our studies revealed widespread and early activity of the parietal cortex for praxis movements in normal subjects. This early activity was also seen in the inferior temporal cortex. The distribution and timing of this activity was different when comparing it to simple movements, which generally had activity confined to the premotor cortex. Moreover, an active functional network was seen between the parietal and premotor cortices of the left hemisphere for praxis movements. This network differed from that seen in patients with ideomotor apraxia, where activity in the right hemisphere parietal and premotor areas became predominant. These studies provide evidence of distinct and early parietal activity before praxis and a functional network that is involved in planning and execution, which can be modified in the event of brain injury

Neural activation differences in amputees during imitation of intact versus amputee movements

The mirror neuron system (MNS) has been attributed with increased activation in motor-related cortical areas upon viewing of another's actions. Recent work suggests that limb movements that are similar and dissimilar in appearance to that of the viewer equivalently activate the MNS. It is unclear if this result can be observed in the action encoding areas in amputees who use prosthetic devices. Intact subjects and upper extremity amputee prosthesis users were recruited to view video demonstrations of tools being used by an intact actor and a prosthetic device user. All subjects pantomimed the movements seen in the video while recording electroencephalography (EEG). Intact subjects showed equivalent left parietofrontal activity during imitation planning after watching the intact or prosthetic arm. Likewise, when prosthesis users imitated prosthesis demonstrations, typical left parietofrontal activation was observed. When prosthesis users imitated intact actors, an additional pattern was revealed which showed greater activity in right parietal and occipital regions that are associated with the mentalizing system. This change may be required for prosthesis users to plan imitation movements in which the limb states between the observed and the observer do not match. The finding that prosthesis users imitating other prosthesis users showed typical left parietofrontal activation suggests that these subjects engage normal planning related activity when they are able to imitate a limb matching their own. This result has significant implications on rehabilitation, as standard therapy involves training with an intact occupational therapist, which could necessitate atypical planning mechanisms in amputees when learning to use their prosthesis

Contesting authentic practice and ethical authority in adventure tourism

This paper examines the discourses of authenticity and ethics used among adventure tourists regarding the use of the natural environment. In one case, full-time traveling rock climbers use their dedication to the sport and annual visits to the Red River Gorge as evidence for their authoritative voice on ethical climbing practice. While they identify the growing numbers of leisure climbers as a problem for sustainability, many also take up temporary employment as guides and are directly involved in the introduction of new climbers to the area. In another case, two groups of wilderness enthusiasts – “ADK 46ers” and “Summit Stewards” – lament the environmental and social impacts of other recreational users in the Adirondack Park. Despite being visitors themselves, Summit Stewards and 46ers use their sense of place and knowledge of Adirondack history and ecology to substantiate their authority as purveyors of ethical practice. In both cases, senses of responsibility are inspired by senses of place, but are articulated through notions of authenticity and used as justification for ethical authority. While validating their presence in these outdoor spaces, the use of such rhetoric also minimizes their own impacts yielding further tensions among user groups

Genomic rearrangements of the PRPF31 gene account for

PURPOSE. To determine whether genomic rearrangements in the PRPF31 (RP11) gene are a frequent cause of autosomal dominant retinitis pigmentosa (adRP) in a cohort of patients with adRP. METHODS. In a cohort of 200 families with adRP, disease-causing mutations have previously been identified in 107 families. To determine the cause of disease in the remaining families, linkage testing was performed with markers for 13 known adRP loci. In a large American family, evidence was found of linkage to the PRPF31 gene, although DNA sequencing revealed no mutations. SNP testing throughout the genomic region was used to determine whether any part of the gene was deleted. Aberrant segregation of a SNP near exon 1 was observed, leading to the testing of additional SNPs in the region. After identifying an insertion-deletion mutation, the remaining 92 families were screened for genomic rearrangements in PRPF31 with multiplex ligation-dependent probe amplification (MLPA). RESULTS. Five unique rearrangements were identified in the 93 families tested. In the large family used for linkage exclusion testing, an insertion-deletion was found that disrupts exon 1. The other four mutations identified in the cohort were deletions, ranging from 5 kb to greater than 45 kb. Two of the large deletions encompass all PRPF31 as well as several adjacent genes. The two smaller deletions involve either 5 or 10 completely deleted exons. CONCLUSIONS. In an earlier long-term study of 200 families with adRP, disease-causing mutations were identified in 53% of the families. Mutation-testing by sequencing missed large-scale genomic rearrangements such as insertions or deletions. MLPA was used to identify genomic rearrangements in PRPF31 in five families, suggesting a frequency of approximately 2.5%. Mutations in PRPF31 now account for 8% of this adRP cohort

State Mandates, Housing Elements, and Low-income Housing Production

In order to create low-income housing opportunities and mitigate exclusionary zoning, in 1968 Congress mandated that municipalities receiving comprehensive planning funds must create a housing element. In tandem, many states mandated that municipal housing elements must accommodate low-income housing needs. After examining empirical research for California, Florida, Illinois, and Minnesota, this review found aspirational success because those states rewarded the municipal planning process. In order to increase low-income housing, this review argues for state housing policy reform. Under US Department of Housing and Urban Development’s revised fair housing rule, which requires an assessment of local data, states can no longer ignore the exclusionary behavior of municipalities

Genetics Mutations in RPGR and RP2 Account for 15% of Males with Simplex Retinal Degenerative Disease

PURPOSE. To determine the proportion of male patients presenting simplex retinal degenerative disease (RD: retinitis pigmentosa [RP] or cone/cone-rod dystrophy [COD/CORD]) with mutations in the X-linked retinal degeneration genes RPGR and RP2. METHODS. Simplex males were defined as patients with no known affected family members. Patients were excluded if they had a family history of parental consanguinity. Blood samples from a total of 214 simplex males with a diagnosis of retinal degeneration were collected for genetic analysis. The patients were screened for mutations in RPGR and RP2 by direct sequencing of PCR-amplified genomic DNA. RESULTS. We identified pathogenic mutations in 32 of the 214 patients screened (15%). Of the 29 patients with a diagnosis of COD/CORD, four mutations were identified in the ORF15 mutational hotspot of the RPGR gene. Of the 185 RP patients, three patients had mutations in RP2 and 25 had RPGR mutations (including 12 in the ORF15 region). CONCLUSIONS. This study represents mutation screening of RPGR and RP2 in the largest cohort, to date, of simplex males affected with RP or COD/CORD. Our results demonstrate a substantial contribution of RPGR mutations to retinal degenerations, and in particular, to simplex RP. Based on our findings, we suggest that RPGR should be considered as a first tier gene for screening isolated males with retinal degeneration. (Invest Ophthalmol Vis Sci. 2012;53:8232-8237

An inclusive Research and Education Community (iREC) model to facilitate undergraduate science education reform

Funding: This work was supported by Howard Hughes Medical Institute grants to DIH is GT12052 and MJG is GT15338.Over the last two decades, there have been numerous initiatives to improve undergraduate student outcomes in STEM. One model for scalable reform is the inclusive Research Education Community (iREC). In an iREC, STEM faculty from colleges and universities across the nation are supported to adopt and sustainably implement course-based research – a form of science pedagogy that enhances student learning and persistence in science. In this study, we used pathway modeling to develop a qualitative description that explicates the HHMI Science Education Alliance (SEA) iREC as a model for facilitating the successful adoption and continued advancement of new curricular content and pedagogy. In particular, outcomes that faculty realize through their participation in the SEA iREC were identified, organized by time, and functionally linked. The resulting pathway model was then revised and refined based on several rounds of feedback from over 100 faculty members in the SEA iREC who participated in the study. Our results show that in an iREC, STEM faculty organized as a long-standing community of practice leverage one another, outside expertise, and data to adopt, implement, and iteratively advance their pedagogy. The opportunity to collaborate in this manner and, additionally, to be recognized for pedagogical contributions sustainably engages STEM faculty in the advancement of their pedagogy. Here, we present a detailed pathway model of SEA that, together with underpinning features of an iREC identified in this study, offers a framework to facilitate transformations in undergraduate science education.Peer reviewe

Part I: nature sports: a unifying concept

info:eu-repo/semantics/publishedVersio