2,678 research outputs found
Tracing of Neuronal Connections in the Human Brain by Magnetic Resonance Imaging in vivo
Axon degeneration after disruption of fibre tracts in the mammalian nervous system is accompanied by myelin breakdown which leads to changes in its magnetic resonance properties. In two patients with pure motor strokes due to small ischaemic lesions restricted to the internal capsule, magnetic resonance imaging disclosed a narrow band of pathological signal increase descending band-like into the brain stem and ascending to the precentral gyrus, which corresponded to the well-known path of the pyramidal tract. The findings suggest that in man anterograde and possibly retrograde fibre degeneration can be traced in vivo by conventional magnetic resonance imaging techniques. Critical conditions are the presence of small, strategically located lesions, appropriate choice of imaging plane, and the interval between time of lesion and of imaging. This demonstration may open a new era for functional neuroanatomy of man
Scots pine (pinus sylvestris L.) growth suppression and adverse effects on human health due to air pollution in the upper Silesian Industrial District (USID), southern Poland
Air pollution emissions were not continually
monitored in the Upper Silesian Industrial District
(USID), southern Poland, and data is only available
for the last 20 years. Long-lasting and severe tree ring
reductions in pines growing 5–20 km north of the
USID area recorded particularly high levels of air
pollution emissions in the period 1950–1990. Especially
high amounts of reductions and many missing
rings were found in the period 1964–1981. At
the same time, pines growing 60 km west of the
USID do not record deep ring reductions; this
proves that the phenomenon is of a regional nature.
Increases in infant mortality and lung, bronchial,
and tracheal cancer morbidity rates among males
were also recorded in the USID during periods of
high air pollution. Infant mortality rates increased
several years after the tree ring reductions. Therefore,
it may be possible to use tree ring reductions
as an early indicator of the occurrence of adverse
effects on human health
Simplified Frame and Symbol Synchronization for 4–CPFSK with h=0.25
This paper examines the problem of rapid frame and symbol synchronization techniques intended particularly for constant envelope modulation formats M–CPFSK with modulation index h=1/M which are used in strictly bandwidth limited narrowband industrial applications. The data aided and non data aided versions of the algorithm based on digital frequency discrimination are discussed and compared against the synchronization techniques found in literature. Sample wise pattern correlation technique for joint frame and symbol synchronization is also studied. With the focus on a practical digital implementation the advantages and disadvantages of the described approaches are discussed
Deafness Mental Health Needs Assessment: A Model
The success of any new program often depends on an accurate needs assessment of the population to be served. Program planning is particularly difficult for low incidence disabilities, such as deafness. This paper presents a model to assist practitioners in community mental health program planning for deaf adults. The model is applied to a large metropolitan community in the southwestern part of the United States. Several issues emerge as a result of applying this model and we make recommendations for more effective mental health service provision based on these issues
Implementation of Industrial Narrow Band Communication System into SDR Concept
The rapid expansion of the digital signal processing has penetrated recently into a sphere of high performance industrial narrow band communication systems which had been for long years dominated by the traditional analog circuit design. Although it brings new potential to even increase the efficiency of the radio channel usage it also forces new challenges and compromises radio designers have to face. In this article we describe the design of the IF sampling industrial narrowband radio receiver, optimize a digital receiver structure implemented in a single FPGA circuit and study the performance of such radio receiver architecture. As an evaluation criterion the communication efficiency in form of maximum usable receiver sensitivity, co-channel rejection, adjacent channel selectivity and radio blocking measurement have been selected
Deaf Employment Assistance Network: A Model for Employment Service Delivery
The successful rehabilitation of deaf clients depends on attention to both individual and environmental factors which hinder vocational attainment and satisfaction. Service providers should be aware of and utilize employment and employability interventions which address these factors. This paper presents a comprehensive model for employment service delivery. An ecological framework is outlined, the model is described, and discussion is offered
Validation of the German Revised Addenbrooke's Cognitive Examination for Detecting Mild Cognitive Impairment, Mild Dementia in Alzheimer's Disease and Frontotemporal Lobar Degeneration
Background/Aims: The diagnostic accuracy of the German version of the revised Addenbrooke's Cognitive Examination (ACE-R) in identifying mild cognitive impairment (MCI), mild dementia in Alzheimer's disease (AD) and mild dementia in frontotemporal lobar degeneration (FTLD) in comparison with the conventional Mini Mental State Examination (MMSE) was assessed. Methods: The study encompasses 76 cognitively healthy elderly individuals, 75 patients with MCI, 56 with AD and 22 with FTLD. ACE-R and MMSE were validated against an expert diagnosis based on a comprehensive diagnostic procedure. Statistical analysis was performed using the receiver operating characteristic method and regression analyses. Results: The optimal cut-off score for the ACE-R for detecting MCI, AD, and FTLD was 86/87, 82/83 and 83/84, respectively. ACE-R was superior to MMSE only in the detection of patients with FTLD {[}area under the curve (AUC): 0.97 vs. 0.92], whilst the accuracy of the two instruments did not differ in identifying MCI and AD. The ratio of the scores of the memory ACE-R subtest to verbal fluency subtest contributed significantly to the discrimination between AD and FTLD (optimal cut-off score: 2.30/2.31, AUC: 0.77), whereas the MMSE and ACE-R total scores did not. Conclusion: The German ACE-R is superior to the most commonly employed MMSE in detecting mild dementia in FTLD and in the differential diagnosis between AD and FTLD. Thus it might serve as a valuable instrument as part of a comprehensive diagnostic workup in specialist centres/clinics contributing to the diagnosis and differential diagnosis of the cause of dementia. Copyright (C) 2010 S. Karger AG, Base
The anatomy of fronto-occipital connections from early blunt dissections to contemporary tractography
The evaluation of a modified technique of Total Body Irradiation in respect of treatment results and toxicity
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