Motor Protein KIF1A Is Essential for Hippocampal Synaptogenesis and Learning Enhancement in an Enriched Environment

SummaryEnvironmental enrichment causes a variety of effects on brain structure and function. Brain-derived neurotrophic factor (BDNF) plays an important role in enrichment-induced neuronal changes; however, the precise mechanism underlying these effects remains uncertain. In this study, a specific upregulation of kinesin superfamily motor protein 1A (KIF1A) was observed in the hippocampi of mice kept in an enriched environment and, in hippocampal neurons in vitro, BDNF increased the levels of KIF1A and of KIF1A-mediated cargo transport. Analysis of Bdnf+/− and Kif1a+/− mice revealed that a lack of KIF1A upregulation resulted in a loss of enrichment-induced hippocampal synaptogenesis and learning enhancement. Meanwhile, KIF1A overexpression promoted synaptogenesis via the formation of presynaptic boutons. These findings demonstrate that KIF1A is indispensable for BDNF-mediated hippocampal synaptogenesis and learning enhancement induced by enrichment. This is a new molecular motor-mediated presynaptic mechanism underlying experience-dependent neuroplasticity

Diagnosis and treatment of macrocytic anemias in adults

Anemia is one of the most common health problems in the primary care setting. Macrocytosis in adults is defined as a red blood cell (RBC) mean corpuscular volume (MCV) >100 femtoliter (fL). Macrocytic anemias are generally classified into megaloblastic or nonmegaloblastic anemia. Megaloblastic anemia is caused by deficiency or impaired utilization of vitamin B12 and/or folate, whereas nonmegaloblastic macrocytic anemia is caused by various diseases such as myelodysplastic syndrome (MDS), liver dysfunction, alcoholism, hypothyroidism, certain drugs, and by less commonly inherited disorders of DNA synthesis. Macrocytic anemias are treated with cause-specific therapies, and it is crucial to differentiate nonmegaloblastic from megaloblastic anemia. Because MDS and myeloid neoplasms commonly affect the elderly, primary care physicians may encounter more cases of macrocytic anemias in the near future, as the older population increases. When MDS is suspected along with leukocytopenia and/or thrombocytopenia with anemia, a hematology consultation may be appropriate

Study of the II Network as the Compound Slot Equivalent Circuit Model

A combination of Method of Moments (MoM) and compound slot Equivalent Circuit Model for linear array design is presented in this document. From the S Matrix of the single element, the more suitable network for its characterization is analyzed and selected. Then according to the radiation requirements of the desired array, the elements are designed and then properly connected by means of Forward Matching Procedure (FMP), which takes into account impedance matters in order to keep the input matched at the designing frequency. Comparison between HFSS simulations and MoM-FMP results are also presented. First part of this work was introduced in (1)(2) but a summary is included here to make the understanding easier

Fabrication of Alternating-Phase Fed Single-Layer Slotted Waveguide Arrays using Plastic Materials with Metal-Plating

Abstract Lightweight single-layer slotted waveguide array antennas are fabricated using plastic materials with metal-plating. A plastic material that has good heat-radiation properties is investigated. Three types of antennas are fabricated in milling process, using ABS resin, heatradiating plastic, and aluminium alloy. In measurements, all three types of antennas are confirmed to have almost the same VSWR and gain around 25GHz frequency band

Diseño de Arrays de Ranuras Compuestas Mediante Circuito Equivalente

Results of the methodology presented in [1] is shown in this document. By means of the equivalent circuit model [2][3] of the slot, a combination of Method of Moments (MoM) and Forward Matching Procedure (FMP) is used to design a sub-array of compound slots. According to this, the system can be seen as a matched electric circuit and/or as a Nelements radiating device. Comparison between commercial solvers and proposed method are shown in this document, revealing that the mutual coupling between elements is a tiltingangle-dependant parameter

Moment method analysis of parallel plate slot antennas

The authors propose a moment method analysis for the analysis of a parallel plate slot array, excited by a feed waveguide, based on the Flocket's theorem. The beam tilt of the incident wave, due to the frequency dependence of the excitation wavelength, is considered by using a complex Hertzian potential and periodic boundary conditions. A phase shift, that depends on the frequency, is included in the periodic conditions. This analysis can also be used for beam scanning arrays

Source reconstruction technique for slot array antennas using the Gerchberg-Papoulis algorithm

A source reconstruction technique for slot array antennas is presented. By exploiting the information about the positions and the polarizations of slots to the Gerchberg-Papoulis iterative algorithm, the field on the slots is accurately reconstructed. The proposed technique is applied to the source reconstruction of a K-band radial line slot antenna (RLSA), and the simulated and measured results are presente

Full model análisis of a radial line slot antena and efficiency assesment as functions of slot pair design

A full-model structure of CA-RLSA with feeder has been analyzed by using the MoM. The results of the calculated aperture-field show reasonable agreement with the experimental ones on the outermost round of slot pairs by the full-model analysis. We estimate effect of distance between slot pairs in φ-direction. As a result of design, enhance of the aperture efficiency is 2%. We propose a design method by using this full-model analysis. The ρ-positions of the slot pairs are adjusted respectively to suppress the deviation of the phase in the φ−direction. As a result of calculation in the 22 GHzband, dielectric constant εr=2.2, height h=3.2 mm, the three kind of parameters are determined as the aperture efficiency is high