Analysis of eye and head coordination in a visual peripheral recognition task

Coordinated eye and head movements simultaneously occur to scan the visual world for relevant targets. However, measuring both eye and head movements in experiments allowing natural head movements may be challenging. This paper provides an approach to study eye-head coordination: First, we demonstra- te the capabilities and limits of the eye-head tracking system used, and compare it to other technologies. Second, a beha- vioral task is introduced to invoke eye-head coordination. Third, a method is introduced to reconstruct signal loss in video- based oculography caused by cornea reflection artifacts in order to extend the tracking range. Finally, parameters of eye- head coordination are identified using EHCA (eye-head co- ordination analyzer), a MATLAB software which was developed to analyze eye-head shifts. To demonstrate the capabilities of the approach, a study with 11 healthy subjects was performed to investigate motion behavior. The approach presented here is discussed as an instrument to explore eye-head coordination, which may lead to further insights into attentional and motor symptoms of certain neurological or psychiatric diseases, e.g., schizophrenia.

Coordination of Family Preservation Services in a Rural Community: A Case Study

Family preservation programs designed to prevent the out-of-home placement of children depend on the coordination of services from multiple agencies. Little is known regarding how coordination occurs. This case study examined this issue. Information was sought from all workers who provided services to each of five families and 'from families' case records. Thirty-one workers were interviewed with a semi-structured interview schedule containing rating scales and questions with open-ended response formats. Case records were reviewed with a case record review form. Analyses of data revealed the following. Services were coordinated to a moderate degree but that coordination deteriorated over time. Workers elaborated how aspects of communities, human service agencies, workers, and families affected coordination. Implications of findings for future research were drawn.

Long-term synaptic facilitation of tail sensorimotor connections in {\it Aplysia\/}

Long-term sensitization in Aplysia is a well studied model for the examination of the cellular and molecules mechanisms of long-term memory. Several lines of evidence suggest long-term sensitization is mediated at least partially by long-term synaptic facilitation between the sensory and motor neurons. The sensitization training and one of its analogues, serotonin (5-HT), can induce long-term facilitation. In this study, another analogue to long-term sensitization training has been developed. Stimulation of peripheral nerves of pleural-pedal ganglia preparation induced long-term facilitation at both 24 hr and 48 hr. This is the first report that long-term facilitation in Aplysia persists for more than 24 hr, which is consistent with the observation that long-term sensitization lasts for more than one day. Thus, the data support the hypothesis that long-term facilitation is an important mechanism for long-term sensitization.^ One of the major differences between short-term and long-term facilitation is that long-term facilitation requires protein synthesis. Therefore, the effects of anisomycin, a protein synthesis inhibitor, on long-term facilitation was examined. Long-term facilitation induced by nerve stimulation was inhibited by 2 $\mu$M anisomycin, which inhibits $\sim$90% of protein synthesis. Nevertheless, at higher concentration (20 $\mu$M), anisomycin induced long-term facilitation by itself, which raises an interesting question about the function of anisomycin other than protein synthesis inhibition.^ Since protein synthesis is critical for long-term facilitation, a major goal is to identify and functionally characterize the molecules whose mRNA levels are altered during the formation of long-term facilitation. Behavioral training or its analogues (nerve stimulation and 5-HT) increases the level of mRNA of calmodulin (CaM). Thus, the role of Ca$\sp{2+}$-CaM-dependent protein kinase II (CaMKII), a major substrate of CaM, in long-term facilitation induced by nerve stimulation was examined. KN-62, a specific CaMKII inhibitor, did not block either the induction or the maintenance of long-term facilitation induced by nerve stimulation. These data indicate that CaMKII may not be involved in long-term facilitation. Another protein whose mRNA level of a molecule was increased by the behavioral training and the treatment of 5-HT is Aplysia tolloid/BMP-1-like protein 1 (apTBL-1). Tolloid in Drosophila and BMP-1 in human tissues are believed to be secreted as a metalloprotease to activate TGF-$\beta.$ Thus, the long-term effects of recombinant human TGF-$\beta1$ on synaptic strength were examined. Treatment of ganglia with TGF-$\beta1$ produced long-term facilitation, but not short-term or intermediate-term facilitation ($\le$4 hr). In addition, TGF-$\beta1$ and 5-HT were not additive in producing long-term facilitation, which indicates an interaction between two cascades. Moreover, 5-HT-induced facilitation (at both 24 hr and 48 hr) and nerve stimulation-induced facilitation (at 24 hr) were inhibited by TGF-$\beta$ sRII, a TGF-$\beta$ inhibitor. These results suggest that TGF-$\beta$ is part of the cascade of events underlying long-term sensitization, and also indicate that a signaling molecule used in development may also have functions in adult neuronal plasticity. ^

Grey matter volumetric changes related to recovery from hand paresis after cortical sensorimotor stroke

Preclinical studies using animal models have shown that grey matter plasticity in both perilesional and distant neural networks contributes to behavioural recovery of sensorimotor functions after ischaemic cortical stroke. Whether such morphological changes can be detected after human cortical stroke is not yet known, but this would be essential to better understand post-stroke brain architecture and its impact on recovery. Using serial behavioural and high-resolution magnetic resonance imaging (MRI) measurements, we tracked recovery of dexterous hand function in 28 patients with ischaemic stroke involving the primary sensorimotor cortices. We were able to classify three recovery subgroups (fast, slow, and poor) using response feature analysis of individual recovery curves. To detect areas with significant longitudinal grey matter volume (GMV) change, we performed tensor-based morphometry of MRI data acquired in the subacute phase, i.e. after the stage compromised by acute oedema and inflammation. We found significant GMV expansion in the perilesional premotor cortex, ipsilesional mediodorsal thalamus, and caudate nucleus, and GMV contraction in the contralesional cerebellum. According to an interaction model, patients with fast recovery had more perilesional than subcortical expansion, whereas the contrary was true for patients with impaired recovery. Also, there were significant voxel-wise correlations between motor performance and ipsilesional GMV contraction in the posterior parietal lobes and expansion in dorsolateral prefrontal cortex. In sum, perilesional GMV expansion is associated with successful recovery after cortical stroke, possibly reflecting the restructuring of local cortical networks. Distant changes within the prefrontal-striato-thalamic network are related to impaired recovery, probably indicating higher demands on cognitive control of motor behaviour.

Innovation, Coordination, and Positioning: Locational Policies of Secondary Capital City Regions

Capital cities that are not the economic centers of their nations - so-called secondary capital cities - tend to be overlooked in the field of political science. Consequentially, there is a lack of research and resulting theory describing their political economy and their formulated policies. This paper analyzes how secondary capital cities try to develop and position themselves through the formulation of locational policies. By linking three different theoretical strands - the Regional Innovation System approach, the concept of locational policies, and the regime perspective - this paper proposes a framework to study the the economic and political dynamics in secondary capital cites.

A Drosophila XPD model links cell cycle coordination with neuro-development and suggests links to cancer

XPD functions in transcription, DNA repair and in cell cycle control. Mutations in human XPD (also known as ERCC2) mainly cause three clinical phenotypes: xeroderma pigmentosum (XP), Cockayne syndrome (XP/CS) and trichothiodystrophy (TTD), and only XP patients have a high predisposition to developing cancer. Hence, we developed a fly model to obtain novel insights into the defects caused by individual hypomorphic alleles identified in human XP-D patients. This model revealed that the mutations that displayed the greatest in vivo UV sensitivity in Drosophila did not correlate with those that led to tumor formation in humans. Immunoprecipitations followed by targeted quantitative MS/MS analysis showed how different xpd mutations affected the formation or stability of different transcription factor IIH (TFIIH) subcomplexes. The XP mutants most clearly linked to high cancer risk, Xpd R683W and R601L, showed a reduced interaction with the core TFIIH and also an abnormal interaction with the Cdk-activating kinase (CAK) complex. Interestingly, these two XP alleles additionally displayed high levels of chromatin loss and free centrosomes during the rapid nuclear division phase of the Drosophila embryo. Finally, the xpd mutations showing defects in the coordination of cell cycle timing during the Drosophila embryonic divisions correlated with those human mutations that cause the neurodevelopmental abnormalities and developmental growth defects observed in XP/CS and TTD patients.