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Our ability to select relevant information from the environment is limited by the resolution of attention – i.e., the minimum size of the region that can be selected. Neural mechanisms that underlie this limit and its development are not yet understood. Functional magnetic resonance imaging (fMRI) was performed during an object tracking task in 7- and 11-year-old children, and in young adults. Object tracking activated canonical fronto-parietal attention systems and motion-sensitive area MT in children as young as 7 years. Object tracking performance improved with age, together with stronger recruitment of parietal attention areas and a shift from low-level to higher-level visual areas. Increasing the required resolution of spatial attention – which was implemented by varying the distance between target and distractors in the object tracking task – led to activation increases in fronto-insular cortex, medial frontal cortex including anterior cingulate cortex (ACC) and supplementary motor area, superior colliculi, and thalamus. This core circuitry for attentional precision was recruited by all age groups, but ACC showed an age-related activation reduction. Our results suggest that age-related improvements in selective visual attention and in the resolution of attention are characterized by an increased use of more functionally specialized brain regions during the course of development.
A cGMP signaling cascade composed of C-type natriuretic peptide, the guanylyl cyclase receptor Npr2 and cGMP-dependent protein kinase I (cGKI) controls the bifurcation of sensory axons upon entering the spinal cord during embryonic development. However, the impact of axon bifurcation on sensory processing in adulthood remains poorly understood. To investigate the functional consequences of impaired axon bifurcation during adult stages we generated conditional mouse mutants of Npr2 and cGKI (Npr2fl/fl;Wnt1Cre and cGKIKO/fl;Wnt1Cre) that lack sensory axon bifurcation in the absence of additional phenotypes observed in the global knockout mice. Cholera toxin labeling in digits of the hind paw demonstrated an altered shape of sensory neuron termination fields in the spinal cord of conditional Npr2 mouse mutants. Behavioral testing of both sexes indicated that noxious heat sensation and nociception induced by chemical irritants are impaired in the mutants, whereas responses to cold sensation, mechanical stimulation, and motor coordination are not affected. Recordings from C-fiber nociceptors in the hind limb skin showed that Npr2 function was not required to maintain normal heat sensitivity of peripheral nociceptors. Thus, the altered behavioral responses to noxious heat found in Npr2fl/fl;Wnt1Cre mice is not due to an impaired C-fiber function. Overall, these data point to a critical role of axonal bifurcation for the processing of pain induced by heat or chemical stimuli.
A sound and well-functioning legal system will encourage growth in investment and create opportunities for investors. Trademarks as part of intellectual property play an important role in the future development of a country. A mark or symbol is needed in order to give products and services identity and to distinguish them and their qualities from identical or similar products and services of a competitor.
This research studies, examines and analyses the degree, nature and function of trademark protection within the legal system of Afghanistan and compare them with the Paris, Madrid and TRIPs agreements. It has been divided into four chapters: Chapter one provides general information and an overview of the current legal system of Afghanistan. Chapter two studies and analyses international agreements pertaining to the legal protection of trademark. It also critically assesses the ATML compatibility with these agreements: and answers the research question of to what extent the ATML provisions are compatible with them. Chapter three provides information on the different purposes of trademarks from a development perspective and compares the purposes provided by the ATML. Finally, chapter four assesses and examines the acquisition, assignment and termination of trademarks. The conclusions and findings of the thesis are the final section of this research.
Afghanistan, as a transitioning economy, has not developed a solid legal and practical foundation for providing comprehensive protection mechanisms for trademarks as have been articulated in developed countries and international agreements. Accordingly, the Afghan government has not entirely integrated these needs into its legal system and there are some inconsistencies of the ATML with these agreements.
One more challenge is the lack of appropriate legal institutions for issuing, managing, administering and protecting of trademarks. The establishment of a well-functioning administrative institution will serve to fulfil the objectives of the laws. Therefore, the CBR office holds the administrative responsibility for processing the registration of trademarks.
However, the methods and facilities of the CBR office remain outdated, and the office does not have the capacity to provide applicants with up-to-date administrative and technical facilities.
Therefore, legal protection of trademark in Afghanistan is linked not only to the existence of a well functioning of laws, regulations, clear procedures, mechanism and guidelines but also to an efficient and well-functioning administrative office.
Development of T cells in the thymus is tightly controlled to continually produce functional, but not autoreactive, T cells. miRNAs provide a layer of post-transcriptional gene regulation to this process, but the role of many individual miRNAs in T-cell development remains unclear. miR-21 is prominently expressed in immature thymocytes followed by a steep decline in more mature cells. We hypothesized that such a dynamic expression was indicative of a regulatory function in intrathymic T-cell development. To test this hypothesis, we analyzed T-cell development in miR-21-deficient mice at steady state and under competitive conditions in mixed bone-marrow chimeras. We complemented analysis of knock-out animals by employing over-expression in vivo. Finally, we assessed miR-21 function in negative selection in vivo as well as differentiation in co-cultures. Together, these experiments revealed that miR-21 is largely dispensable for physiologic T-cell development. Given that miR-21 has been implicated in regulation of cellular stress responses, we assessed a potential role of miR-21 in endogenous regeneration of the thymus after sublethal irradiation. Again, miR-21 was completely dispensable in this process. We concluded that, despite prominent and highly dynamic expression in thymocytes, miR-21 expression was not required for physiologic T-cell development or endogenous regeneration.