Effects of thyroxine treatment on histology and behavior using the methimazole model of congenital hypothyroidism in the rat

The timing of thyroxine (T4) replacement treatment in congenital hypothyroidism (CH) has been suggested to be important for optimizing cognitive recovery in humans; however this has not been fully established using modern animal models of CH. Consequently, the current studies investigated the ameliorating effects of postnatal T4 treatment on neuropathology and behavior in CH rats. Rat dams were administered methimazole to produce CH offspring, then brain tissue from male CH pups was analyzed to determine the effects of postnatal (P3, P7, P14 and P21) T4 treatment on hippocampal dendritic branching and the expression of nerve growth factor (NGF). Two operant behavioral procedures were employed to confirm and extend previous findings obtained using this model, and to investigate timelines for instigating T4 treatment on improved behavioral outcomes. T4 treatment initiated at P14 was protective of a reduction in dendritic branching in the hippocampus, and initiated at P7 was protective of a reduction of NGF expression in the fimbria of the hippocampus. Induction of CH did not affect the acquisition of simple operant response rules but had a significant effect on the acquisition of complex operant rules subsequently imposed. Furthermore, T4 treatment initiated at P3 protected learning deficits seen following the imposition of complex operant response rules. These findings indicate T4 treatment initiated at P7 is sufficient for the protection of hippocampal NGF expression and dendritic branching but for the protection of complex behavioral abilities T4 treatment is necessary prior to or approximating P3.

Vasoactivity of Rucaparib, a PARP-1 Inhibitor, is a Complex Process that Involves Myosin Light Chain Kinase, P2 Receptors, and PARP Itself

Therapeutic inhibition of poly(ADP-ribose) polymerase (PARP), as monotherapy or to supplement the potencies of other agents, is a promising strategy in cancer treatment. We previously reported that the first PARP inhibitor to enter clinical trial, rucaparib (AG014699), induced vasodilation in vivo in xenografts, potentiating response to temozolomide. We now report that rucaparib inhibits the activity of the muscle contraction mediator myosin light chain kinase (MLCK) 10-fold more potently than its commercially available inhibitor ML-9. Moreover, rucaparib produces additive relaxation above the maximal degree achievable with ML-9, suggesting that MLCK inhibition is not solely responsible for dilation. Inhibition of nitric oxide synthesis using L-NMMA also failed to impact rucaparib's activity. Rucaparib contains the nicotinamide pharmacophore, suggesting it may inhibit other NAD+-dependent processes. NAD+ exerts P2 purinergic receptor-dependent inhibition of smooth muscle contraction. Indiscriminate blockade of the P2 purinergic receptors with suramin abrogated rucaparib-induced vasodilation in rat arterial tissue without affecting ML-9-evoked dilation, although the specific receptor subtypes responsible have not been unequivocally identified. Furthermore, dorsal window chamber and real time tumor vessel perfusion analyses in PARP-1-/- mice indicate a potential role for PARP in dilation of tumor-recruited vessels. Finally, rucaparib provoked relaxation in 70% of patient-derived tumor-associated vessels. These data provide tantalising evidence of the complexity of the mechanism underlying rucaparib-mediated vasodilation.

The Role of Brain-Derived Neurotrophic Factor (BDNF) in the Development of Neurogenic Detrusor Overactivity (NDO)

Neurogenic detrusor overactivity (NDO) is a well known consequence of spinal cord injury (SCI), recognizable after spinal shock, during which the bladder is areflexic. NDO emergence and maintenance depend on profound plastic changes of the spinal neuronal pathways regulating bladder function. It is well known that neurotrophins (NTs) are major regulators of such changes. NGF is the best-studied NT in the bladder and its role in NDO has already been established. Another very abundant neurotrophin is BDNF. Despite being shown that, acting at the spinal cord level, BDNF is a key mediator of bladder dysfunction and pain during cystitis, it is presently unclear if it is also important for NDO. This study aimed to clarify this issue. Results obtained pinpoint BDNF as an important regulator of NDO appearance and maintenance. Spinal BDNF expression increased in a time-dependent manner together with NDO emergence. In chronic SCI rats, BDNF sequestration improved bladder function, indicating that, at later stages, BDNF contributes NDO maintenance. During spinal shock, BDNF sequestration resulted in early development of bladder hyperactivity, accompanied by increased axonal growth of calcitonin gene-related peptide-labeled fibers in the dorsal horn. Chronic BDNF administration inhibited the emergence of NDO, together with reduction of axonal growth, suggesting that BDNF may have a crucial role in bladder function after SCI via inhibition of neuronal sprouting. These findings highlight the role of BDNF in NDO and may provide a significant contribution to create more efficient therapies to manage SCI patients.

Neuromusculature of Gyrodactylus rysavyi, a monogenean gill and skin parasite of the catfish Clarias gariepinus

Phalloidin fluorescence technique, enzyme cytochemistry and immunocytochemistry in conjunction with confocal scanning laser microscopy were used for the first time to describe the nervous and muscle systems of the viviparous monogenean parasite, Gyrodactylus rysavyi inhabiting the gills and skin of the Nile catfish Clarias gariepinus. The body wall muscles are composed of an outer layer of circular fibres, an intermediate layer of paired longitudinal fibres and an inner layer of well-spaced bands of diagonal fibres arranged in two crossed directions. The musculature of the pharynx, intestine, reproductive tract and the most prominent muscles of the haptor were also described. Two characteristic muscular pads were found lying in the anterior region of the haptor in close contact with the hamuli. To each one of these pads, a group of ventral extrinsic muscles was connected. The role of this ventral extrinsic muscle in the body movement was discussed. The mechanism operating the marginal hooklets was also discussed. The central nervous system (CNS) consists of paired cerebral ganglia from which three pairs of longitudinal ventral, lateral and dorsal nerve cords arise. The nerve cords are connected at intervals by many transverse connectives. The CNS is better developed ventrally than dorsally or laterally and it has the highest reactivity for all neuroactive substances examined. Both the central and the peripheral nervous system (PNS) are bilaterally symmetrical. Structural and functional correlates of the neuromusculature of the pharynx, haptor and reproductive tracts were explained. The results implicated acetylcholine, FMRFamide-related peptides (FaRPs) and serotonin in sensory and motor function. The results were compared with those of the monogeneans Macrogyrodactylus clarii and M. congolensis inhabiting the gills and skin respectively of the same host fish C. gariepinus.

Neuromusculature of Macrogyrodactylus congolensis, a monogenean skin parasite of the Nile catfish Clarias gariepinus

Phalloidin fluorescence technique, enzyme cytochemistry and immunocytochemistry, in conjunction with confocal scanning laser microscopy, were used to describe the neuromusculature of the monogenean skin parasite Macrogyrodactylus congolensis from the Nile catfish Clarias gariepinus. The body wall muscles are composed of an outer layer of compactly arranged circular fibres, an intermediate layer of paired longitudinal fibres and an inner layer of well-spaced bands of diagonal fibres arranged in two crossed directions. The central nervous system consists of paired cerebral ganglia from which three pairs of longitudinal ventral, lateral and dorsal nerve cords arise. The nerve cords are connected at intervals by many transverse connectives. Both central and peripheral nervous systems are bilaterally symmetrical and better developed ventrally than laterally and dorsally. Structural and functional correlates of the neuromusculature of the pharynx, haptor and reproductive tracts were examined. Results implicate acetylcholine, FMRFamide-related peptides and serotonin in sensory and motor function. The results were compared with those of Macrogyrodactylus clarii, a gill parasite of the same host fish C. gariepinus.

Neuromusculature of Macrogyrodactylus clarii, a monogenean gill parasite of the Nile catfish Clarias gariepinus in Egypt

Phalloidin fluorescence technique, enzyme cytochemistry and immunocytochemistry in conjunction with confocal scanning laser microscopy have been used for the first time to describe the nervous and muscle systems of the viviparous monogenean gill parasite, Macrogyrodactylus clarii. The gross spatial arrangement of muscle and associated cholinergic, peptidergic and aminergic innervations has been examined. The central nervous system (CNS) consists of paired cerebral ganglia from which emanate three pairs of longitudinal ventral, lateral and dorsal nerve cords, connected at intervals by transverse connectives. The CNS is better developed ventrally than dorsally or laterally, and has the strongest reactivity for all neuroactive substances examined. Structural and functional correlates of the neuromusculature of the pharynx, haptor and reproductive tracts have been examined. Results implicate acetylcholine, FMRFamide-related peptides (FaRPs) and serotonin in sensory and motor function in this monogenean, although confirmatory physiological data are obviously required.

Larval development of the pedunculate barnacles Octolasmis angulata Aurivillius 1894 and Octolasmis cor Aurivillius 1892 (Cirripedia: Thoracica: Poecilasmatidae) from the gills of the mud crab, Scylla tranquebarica Fabricius, 1798

Detailed studies of larval development of Octolasmis angulata and Octolasmis cor are pivotal in understanding the larval morphological evolution as well as enhancing the functional ecology. Six planktotrophic naupliar stages and one non-feeding cyprid stage are documented in details for the first time for the two species of Octolasmis. Morphologically, the larvae of O. angulata and O. cor are similar in body size, setation patterns on the naupliar appendages, labrum, dorsal setae-pores, frontal horns, cyprid carapace, fronto-lateral gland pores, and lattice organs. Numbers of peculiarities were observed on the gnathobases of the antennae and mandible throughout the naupliar life-cycle. The setation pattern on the naupliar appendages are classified based on the segmentation on the naupliar appendages. The nauplius VI of both species undergoes a conspicuous change before metamorphosis into cyprid stage. The cyprid structures begin to form and modify beneath the naupliar body towards the end of stage VI. This study emphasises the importance of the pedunculate barnacle larval developmental studies not only to comprehend the larval morphological evolution but also to fill in the gaps in understanding the modification of the naupliar structures to adapt into the cyprid life-style.

Time-dependent tegumental surface changes in juvenile Fasciola gigantica in response to triclabendazole treatment in goat

Triclabendazole (TCBZ), the anthelmintic drug active against both mature and immature liver flukes, was used to investigate the effect of in vivo treatment on the tegumental surface of juvenile Fasciola gigantica. Five goats were infected with 150 F. gigantica metacercariae each by oral gavage. Four of them were treated with single dose of TCBZ at 10mg/kg at four weeks post-infection. They were euthanized at 0 (untreated), 24, 48, 72 and 96h post treatment. Juvenile flukes were manually retrieved from the goat livers and processed for scanning electron microscopy. In control flukes, the anterior region was adorned with sharply pointed spines projecting away from the surface, while in the posterior region, spines become shorter and narrower, loosing serration and with the appearance of distinct furrows and papillae. The dorsal surface retained the same pattern of surface architecture similar to that of ventral surface. Flukes obtained from 24h post-treatment did not show any apparent change and were still very active. However, there were limited movements and some blebbing, swelling, deposition of tegumental secretions and some flattening displayed by the flukes of 48h post-treatment. All the worms were found dead 72h post-treatment and showed advanced level of tegumental disruptions, consisting of severe distortion of spines, sloughing off the tegument to expose the basal lamina, formation of pores and isolated patches of lesions. By 96h post-treatment, the disruption was extremely severe and the tegument was completely sheared off causing deeper lesions that exposed the underlying musculature. The disruption was more severe at posterior than anterior region and on ventral than dorsal surface. The present study further establishes the time-course of TCBZ action in vivo with 100% efficacy against the juvenile tropical liver fluke.

Abnormal alterations in the Ca2+/CaV1.2/calmodulin/caMKII signaling pathway in a tremor rat model and in cultured hippocampal neurons exposed to Mg2+-free solution

Voltage-dependent calcium channels (VDCCs) are key elements in epileptogenesis. There are several binding-sites linked to calmodulin (CaM) and several potential CaM-dependent protein kinase II (CaMKII)-mediated phosphorylation sites in CaV1.2. The tremor rat model (TRM) exhibits absence‑like seizures from 8 weeks of age. The present study was performed to detect changes in the Ca2+/CaV1.2/CaM/CaMKII pathway in TRMs and in cultured hippocampal neurons exposed to Mg2+‑free solution. The expression levels of CaV1.2, CaM and phosphorylated CaMKII (p‑CaMKII; Thr‑286) in these two models were examined using immunofluorescence and western blotting. Compared with Wistar rats, the expression levels of CaV1.2 and CaM were increased, and the expression of p‑CaMKII was decreased in the TRM hippocampus. However, the expression of the targeted proteins was reversed in the TRM temporal cortex. A significant increase in the expression of CaM and decrease in the expression of CaV1.2 were observed in the TRM cerebellum. In the cultured neuron model, p‑CaMKII and CaV1.2 were markedly decreased. In addition, neurons exhibiting co‑localized expression of CaV1.2 and CaM immunoreactivities were detected. Furthermore, intracellular calcium concentrations were increased in these two models. For the first time, o the best of our knowledge, the data of the present study suggested that abnormal alterations in the Ca2+/CaV1.2/CaM/CaMKII pathway may be involved in epileptogenesis and in the phenotypes of TRMs and cultured hippocampal neurons exposed to Mg2+‑free solution.

Differential efficiency of the endocytic machinery in tonic and phasic synapses

Efficient synaptic vesicle membrane recycling is one of the key factors required to sustain neurotransmission. We investigated potential differences in the compensatory endocytic machineries in two glutamatergic synapses with phasic and tonic patterns of activity in the lamprey spinal cord. Post-embedding immunocytochemistry demonstrated that proteins involved in synaptic vesicle recycling, including dynamin, intersectin, and synapsin, occur at higher levels (labeling per vesicle) in tonic dorsal column synapses than in phasic reticulospinal synapses. Synaptic vesicle protein 2 occurred at similar levels in the two types of synapse. After challenging the synapses with high potassium stimulation for 30 min the vesicle pool in the tonic synapse was maintained at a normal level, while that in the phasic synapse was partly depleted along with expansion of the plasma membrane and accumulation of clathrin-coated intermediates at the periactive zone. Thus, our results indicate that an increased efficiency of the endocytic machinery in a synapse may be one of the factors underlying the ability to sustain neurotransmission at high rates.

Characteristics of Corticospinal Projections to the Intrinsic Hand Muscles in Skilled Harpists.

The process of learning to play a musical instrument necessarily alters the functional organisation of the cortical motor areas that are involved in generating the required movements. In the case of the harp, the demands placed on the motor system are quite specific. During performance, all digits with the sole exception of the little finger are used to pluck the strings. With a view to elucidating the impact of having acquired this highly specialized musical skill on the characteristics of corticospinal projections to the intrinsic hand muscles, focal transcranial magnetic stimulation (TMS) was used to elicit motor evoked potentials (MEPs) in three muscles (of the left hand): abductor pollicis brevis (APB); first dorsal interosseous (FDI); and abductor digiti minimi (ADM) in seven harpists. Seven non-musicians served as controls. With respect to the FDI muscle–which moves the index finger, the harpists exhibited reliably larger MEP amplitudes than those in the control group. In contrast, MEPs evoked in the ADM muscle–which activates the little finger, were smaller in the harpists than in the non-musicians. The locations on the scalp over which magnetic stimulation elicited discriminable responses in ADM also differed between the harpists and the non-musicians. This specific pattern of variation in the excitability of corticospinal projections to these intrinsic hand muscles exhibited by harpists is in accordance with the idiosyncratic functional demands that are imposed in playing this instrument.

Fetal umbilical artery Doppler pulsatility index and childhood neurocognitive outcome at 12 years

OBJECTIVE: To determine whether an elevated fetal umbilical artery Doppler (UAD) pulsatility index (PI) at 28 weeks' gestation, in the absence of fetal growth restriction (FGR) and prematurity, is associated with adverse neurocognitive outcome in children aged 12 years.

METHODS: Prospective cohort study, comparing children with a normal fetal UAD PI (<90th centile) (n=110) and those with an elevated PI (≥90th centile) (n=40). UAD was performed at 28, 32 and 34 weeks gestation. At 12 years of age, all children were assessed under standardised conditions at Queen's University, Belfast, UK to determine cognitive and behavioural outcomes using the British Ability Score-II and Achenbach Child Behavioural Checklist Parent Rated Version under standardised conditions. Regression analysis was performed, controlling for confounders such as gender, socioeconomic status and age at assessment.

RESULTS: The mean age of follow-up was 12.4 years (±0.5 SD) with 44% of children male (n=63). When UAD was assessed at 28 weeks, the elevated fetal UAD group had lower scores in cognitive assessments of information processing and memory. Parameters included (1) recall of objects immediate verbal (p=0.002), (2) delayed verbal (p=0.008) and (3) recall of objects immediate spatial (p=0.0016). There were no significant differences between the Doppler groups at 32 or 34 weeks' gestation.

CONCLUSIONS: An elevated UAD PI at 28 weeks' gestation in the absence of FGR or prematurity is associated with lower scores of declarative memory in children aged 12 years. A potential explanation for this is an element of placental insufficiency in the presence of the appropriately grown fetus, which affects the development of the fetal hippocampus and information processing and memory long-term. These findings, however, had no impact on overall academic ability, mental processing and reasoning or overall behavioural function.

Identification of protein complexes in Alzheimer's disease

A Doença de Alzheimer (AD) é a maior doença neurodegenerativa a nível mundial, e a principal causa de demência na população idosa. O processamento da proteína precursora de amilóide (APP) pelas β- e g- secretases origina o peptídeo Aβ, que agrega em oligómeros neurotóxicos e em placas senis. Estes são eventos-chave na patogénese da DA que levam à rutura da neurotransmissão sináptica, morte neuronal e inflamação neuronal do hipocampo e córtex cerebral, causando perda de memória disfunção cognitiva geral. Apesar dos grandes avanços no conhecimento do papel do processamento da APP na DA, a sua função fisiológica ainda não foi totalmente elucidada. Os mapas de interações proteína-proteína (PPI) humanos têm desempenhado um papel importante na investigação biomédica, em particular no estudo de vias de sinalização e de doenças humanas. O método dois-híbrido em levedura (YTH) consiste numa plataforma para a produção rápida de redes de PPI em larga-escala. Neste trabalho foram realizados vários rastreios YTH com o objetivo de identificar proteínas específicas de cérebro humano que interagissem com a APP, ou com o seu domínio intracelular (AICD), tanto o tipo selvagem como com os mutantes Y687F, que mimetizam o estado desfosforilado do resíduo Tyr-687. De facto, a endocitose da APP e a produção de Aβ estão dependentes do estado de fosforilação da Tyr-687. Os rastreios YTH permitiram assim obter de redes proteínas que interagem com a APP, utilizando como “isco” a APP, APPY687F e AICDY687F. Os clones positivos foram isolados e identificados através de sequenciação do cDNA. A maior parte dos clones identificados, 118, correspondia a sequências que codificam para proteínas conhecidas, resultando em 31 proteínas distintas. A análise de proteómica funcional das proteínas identificadas neste estudo e em dois projetos anteriores (AICDY687E, que mimetiza a fosforilação, e AICD tipo selvagem), permitiram avaliar a relevância da fosforilação da Tyr-687. Três clones provenientes do rastreio YTH com a APPY687F foram identificados como um novo transcrito da proteína Fe65, resultante de splicing alternativo, a Fe65E3a (GenBank Accession: EF103274), que codifica para a isoforma p60Fe65. A p60Fe65 está enriquecida no cérebro e os seus níveis aumentam durante a diferenciação neuronal de células PC12, evidenciando o potencial papel que poderá desempenhar na patologia da DA. A RanBP9 é uma proteína nuclear e citoplasmática envolvida em diversas vias de sinalização celulares. Neste trabalho caracterizou-se a nova interação entre a RanBP9 e o AICD, que pode ser regulada pela fosforilação da Tyr-687. Adicionalmente, foi identificada uma nova interação entre a RanBP9 e a acetiltransferase de histonas Tip60. Demonstrou-se ainda que a RanBP9 tem um efeito de regulação inibitório na transcrição mediada por AICD, através da interação com a Tip60, afastando o AICD dos locais de transcrição ativos. O estudo do interactoma da APP/AICD, modelado pela fosforilação da Tyr-687, revela que a APP poderá estar envolvida em novas vias celulares, contribuindo não só para o conhecimento do papel fisiológico da APP, como também auxilia a revelar as vias que levam à agregação de Aβ e neurodegeneração. A potencial relevância deste trabalho relaciona-se com a descoberta de algumas interações proteicas/vias de sinalização que podem que podem ser relevantes para o desenvolvimento de novas estratégias terapêuticas na DA.

Ferroelectric : CNTs structures fabrication for advanced functional nano devices

This work is about the combination of functional ferroelectric oxides with Multiwall Carbon Nanotubes for microelectronic applications, as for example potential 3 Dimensional (3D) Non Volatile Ferroelectric Random Access Memories (NVFeRAM). Miniaturized electronics are ubiquitous now. The drive to downsize electronics has been spurred by needs of more performance into smaller packages at lower costs. But the trend of electronics miniaturization challenges board assembly materials, processes, and reliability. Semiconductor device and integrated circuit technology, coupled with its associated electronic packaging, forms the backbone of high-performance miniaturized electronic systems. However, as size decreases and functionalization increases in the modern electronics further size reduction is getting difficult; below a size limit the signal reliability and device performance deteriorate. Hence miniaturization of siliconbased electronics has limitations. On this background the Road Map for Semiconductor Industry (ITRS) suggests since 2011 alternative technologies, designated as More than Moore; being one of them based on carbon (carbon nanotubes (CNTs) and graphene) [1]. CNTs with their unique performance and three dimensionality at the nano-scale have been regarded as promising elements for miniaturized electronics [2]. CNTs are tubular in geometry and possess a unique set of properties, including ballistic electron transportation and a huge current caring capacity, which make them of great interest for future microelectronics [2]. Indeed CNTs might have a key role in the miniaturization of Non Volatile Ferroelectric Random Access Memories (NVFeRAM). Moving from a traditional two dimensional (2D) design (as is the case of thin films) to a 3D structure (based on a tridimensional arrangement of unidimensional structures) will result in the high reliability and sensing of the signals due to the large contribution from the bottom electrode. One way to achieve this 3D design is by using CNTs. Ferroelectrics (FE) are spontaneously polarized and can have high dielectric constants and interesting pyroelectric, piezoelectric, and electrooptic properties, being a key application of FE electronic memories. However, combining CNTs with FE functional oxides is challenging. It starts with materials compatibility, since crystallization temperature of FE and oxidation temperature of CNTs may overlap. In this case low temperature processing of FE is fundamental. Within this context in this work a systematic study on the fabrication of CNTs - FE structures using low cost low temperature methods was carried out. The FE under study are comprised of lead zirconate titanate (Pb1-xZrxTiO3, PZT), barium titanate (BaTiO3, BT) and bismuth ferrite (BiFeO3, BFO). The various aspects related to the fabrication, such as effect on thermal stability of MWCNTs, FE phase formation in presence of MWCNTs and interfaces between the CNTs/FE are addressed in this work. The ferroelectric response locally measured by Piezoresponse Force Microscopy (PFM) clearly evidenced that even at low processing temperatures FE on CNTs retain its ferroelectric nature. The work started by verifying the thermal decomposition behavior under different conditions of the multiwall CNTs (MWCNTs) used in this work. It was verified that purified MWCNTs are stable up to 420 ºC in air, as no weight loss occurs under non isothermal conditions, but morphology changes were observed for isothermal conditions at 400 ºC by Raman spectroscopy and Transmission Electron Microscopy (TEM). In oxygen-rich atmosphere MWCNTs started to oxidized at 200 ºC. However in argon-rich one and under a high heating rate MWCNTs remain stable up to 1300 ºC with a minimum sublimation. The activation energy for the decomposition of MWCNTs in air was calculated to lie between 80 and 108 kJ/mol. These results are relevant for the fabrication of MWCNTs – FE structures. Indeed we demonstrate that PZT can be deposited by sol gel at low temperatures on MWCNTs. And particularly interesting we prove that MWCNTs decrease the temperature and time for formation of PZT by ~100 ºC commensurate with a decrease in activation energy from 68±15 kJ/mol to 27±2 kJ/mol. As a consequence, monophasic PZT was obtained at 575 ºC for MWCNTs - PZT whereas for pure PZT traces of pyrochlore were still present at 650 ºC, where PZT phase formed due to homogeneous nucleation. The piezoelectric nature of MWCNTs - PZT synthesised at 500 ºC for 1 h was proved by PFM. In the continuation of this work we developed a low cost methodology of coating MWCNTs using a hybrid sol-gel / hydrothermal method. In this case the FE used as a proof of concept was BT. BT is a well-known lead free perovskite used in many microelectronic applications. However, synthesis by solid state reaction is typically performed around 1100 to 1300 ºC what jeopardizes the combination with MWCNTs. We also illustrate the ineffectiveness of conventional hydrothermal synthesis in this process due the formation of carbonates, namely BaCO3. The grown MWCNTs - BT structures are ferroelectric and exhibit an electromechanical response (15 pm/V). These results have broad implications since this strategy can also be extended to other compounds of materials with high crystallization temperatures. In addition the coverage of MWCNTs with FE can be optimized, in this case with non covalent functionalization of the tubes, namely with sodium dodecyl sulfate (SDS). MWCNTs were used as templates to grow, in this case single phase multiferroic BFO nanorods. This work shows that the use of nitric solvent results in severe damages of the MWCNTs layers that results in the early oxidation of the tubes during the annealing treatment. It was also observed that the use of nitric solvent results in the partial filling of MWCNTs with BFO due to the low surface tension (<119 mN/m) of the nitric solution. The opening of the caps and filling of the tubes occurs simultaneously during the refluxing step. Furthermore we verified that MWCNTs have a critical role in the fabrication of monophasic BFO; i.e. the oxidation of CNTs during the annealing process causes an oxygen deficient atmosphere that restrains the formation of Bi2O3 and monophasic BFO can be obtained. The morphology of the obtained BFO nano structures indicates that MWCNTs act as template to grow 1D structure of BFO. Magnetic measurements on these BFO nanostructures revealed a week ferromagnetic hysteresis loop with a coercive field of 956 Oe at 5 K. We also exploited the possible use of vertically-aligned multiwall carbon nanotubes (VA-MWCNTs) as bottom electrodes for microelectronics, for example for memory applications. As a proof of concept BiFeO3 (BFO) films were in-situ deposited on the surface of VA-MWCNTs by RF (Radio Frequency) magnetron sputtering. For in situ deposition temperature of 400 ºC and deposition time up to 2 h, BFO films cover the VA-MWCNTs and no damage occurs either in the film or MWCNTs. In spite of the macroscopic lossy polarization behaviour, the ferroelectric nature, domain structure and switching of these conformal BFO films was verified by PFM. A week ferromagnetic ordering loop was proved for BFO films on VA-MWCNTs having a coercive field of 700 Oe. Our systematic work is a significant step forward in the development of 3D memory cells; it clearly demonstrates that CNTs can be combined with FE oxides and can be used, for example, as the next 3D generation of FERAMs, not excluding however other different applications in microelectronics.

Multi-scale keypoints in V1 and face detection

End-stopped cells in cortical area V1, which combine out- puts of complex cells tuned to different orientations, serve to detect line and edge crossings (junctions) and points with a large curvature. In this paper we study the importance of the multi-scale keypoint representa- tion, i.e. retinotopic keypoint maps which are tuned to different spatial frequencies (scale or Level-of-Detail). We show that this representation provides important information for Focus-of-Attention (FoA) and object detection. In particular, we show that hierarchically-structured saliency maps for FoA can be obtained, and that combinations over scales in conjunction with spatial symmetries can lead to face detection through grouping operators that deal with keypoints at the eyes, nose and mouth, especially when non-classical receptive field inhibition is employed. Al- though a face detector can be based on feedforward and feedback loops within area V1, such an operator must be embedded into dorsal and ventral data streams to and from higher areas for obtaining translation-, rotation- and scale-invariant face (object) detection.