Modulation of iron responsive gene expression and enzymatic activities in response to changes of the iron nutritional status in _Cucumis sativus_ L.

Regulation exerted by the iron status of the plant on the iron deficiency responses was investigated in cucumber roots (_Cucumis sativus_ L.) both at the biochemical and molecular level. Absence of iron induced the expression of the CsFRO1, CsIRT1, CsHA1 and the Cspepc1 transcripts that was followed by an increase in the corresponding enzymatic activities. Supply of iron repressed gene expression, in particular those of the Fe(III)-chelate reductase and for the high affinity iron transporter and reduce the enzymatic activities. Our results confirm and extend the hypothesis of a coordinate regulation of these responses. Besides these two activities strictly correlated with iron deficiency adaptation, we considered also the H+-ATPase and the phosphoenolpyruvate carboxylase, that have been shown to be involved in this response

Molecular mechanisms of neurogenic aging in the adult mouse subventricular zone

In the adult rodent brain, the continuous production of new neurons by neural stem/progenitor cells (NSPCs) residing in specialized neurogenic niches and their subsequent integration into pre-existing cerebral circuitries supports odour discrimination, spatial learning, and contextual memory capabilities. Aging is recognized as the most potent negative regulator of adult neurogenesis. The neurogenic process markedly declines in the aged brain, due to the reduction of the NSPC pool and the functional impairment of the remaining NSPCs. This decline has been linked to the progressive cognitive deficits of elderly individuals and it may also be involved in the onset/progression of neurological disorders. Since the human lifespan has been dramatically extended, the incidence of age-associated neuropsychiatric conditions in the human population has increased. This has prompted efforts to shed light on the mechanisms underpinning the age-related decline of adult neurogenesis, whose knowledge may foster therapeutic approaches to prevent or delay cognitive alterations in elderly patients. In this review, we summarize recent progress in elucidating the molecular causes of neurogenic aging in the most abundant NSPC niche of the adult mouse brain: the subventricular zone (SVZ). We discuss the age-associated changes occurring both in the intrinsic NSPC molecular networks and in the extrinsic signalling pathways acting in the complex environment of the SVZ niche, and how all these changes may steer young NSPCs towards an aged phenotype

KARAKTERISASI MORFOLOGI KOLEKSI TANAMAN KOLEKSI KOPI (COFFEA ARABICA L.) DI KEBUN PECOBAAN GAYO, PONDOK GAJAH, KABUPATEN BENER MERIAH

ABSTRAKPenelitian karakterisasi morfologi varietas tanaman kopi arabika (Coffea arabica L.) telah dilakukan di Kebun Percobaan Gayo, Pondok Gajah, Kabupaten Bener Meriah. Penelitian ini dilakukan pada bulan Juni hingga November 2019. Tujuan penelitian ini untuk melihat karakterisasi morfologi varietas tanaman kopi arabika (Gayo 1, Gayo 2, Ateng Super, C 47 dan P 88). Metode yang digunakan adalah metode survei dengan pengambilan sampel secara sengaja (purposive sampling) yang berumur diatas 5 tahun. Hasil penelitian menunjukkan beberapa perbedaaan dan persamaan diantaranya : 1) pangkal akar yang lebih besar varietas P 88 yaitu 45,5 cm, sedangkan yang lebih kecil varietas Gayo 1 dan Ateng Super 32 cm. 2) batang varietas Gayo 1, Gayo 2, Ateng Super, C 47 memiliki tinggi yang sama yaitu 160 cm, sedangkan P 88 150 cm. 3) panjang dan lebar daun memiliki perbedaan, varietas Gayo 2 memiliki panjang dan lebar daun lebih besar dengan panjang 20,9 cm dan lebar yaitu 9,12 cm, varietas C 47 memiliki panjang dan lebar daun lebih kecil yaitu panjang 16,1 cm dan lebar 6,34 cm. 4) varietas P 88 memiliki diameter bunga lebih besar yaitu 3,56 cm, sedangkan yang lebih kecil yaitu varietas Gayo 1 dengan diameter 2,94 cm. 5) varietas Gayo 2 memiliki panjang buah lebih besar 1,88 cm dan yang lebih kecil varietas P 88 yaitu 1,68 cm. 6) varietas Gayo 1 memiliki biji lebih besar yaitu 1,38 cm, sedangkan yang lebih kecil varietas C 47 yaitu 1 cm. Hasil analisis dendogram menunjukkan varietas tanaman kopi arabika terbagi dua kelompok besar. Kelompok pertama yaitu varietas Gayo 1 dan Gayo 2 dengan nilai koefisien 0,724. Kelompok kedua terdapat tiga varietas dan terbagi 2 cabang, cabang pertama terdiri dari varietas Ateng Super dan C 47 dengan nilai koefisien 0,81 sedangkan cabang kedua yaitu varietas P 88 dengan nilai koefisien 0,758.Kata kunci : Karakteristik, varietas, kopi arabika, morfologiABSTRACTThe morphological characterization research of arabica coffee (Coffea arabica L.) varieties was carried out at the Gayo Experimental Garden, Pondok Gajah, Bener Meriah Regency. This research was conducted in June-November 2019. The purpose of this study was to define the morphological characterization of arabica coffee plant varieties (Gayo 1, Gayo 2, Ateng Super, C 47 and P 88). The method used was a survey method, with purposive sampling over 5 years. The results showed several differences and similarities: 1) the bigger root base of the P 88 variety was 45.5 cm, while the smaller ones were in Gayo 1 and Ateng Super 32 cm varieties. 2) the stems of the varieties Gayo 1, Gayo 2, Ateng Super, C 47 have the same height, namely 160 cm. While P 88 is 150 cm. 3) the leaves' length and width have differences, the Gayo 2 variety has a larger leaf length and width with a length of 20.9 cm and a width of 9.12 cm. Then, the C 47 variety has a smaller leaf length and width, namely 16.1 cm and width 6.34 cm. 4) the P 88 variety has a larger flower diameter of 3.56 cm. The smaller one is the Gayo 1 variety with a diameter of 2.94 cm. 5) the Gayo 2 variety has a larger fruit 1.88 cm and smaller P 88 variety1.68 cm. 6) the Gayo 1 variety had larger seeds, namely 1.38 cm. In comparison, the smaller C 47 variety was 1 cm. The results of the dendrogram analysis showed that Arabica coffee plant varieties were divided into two major groups. The first group is the varieties Gayo 1 and Gayo 2 with a coefficient value of 0.724. The second group consisted of three varieties and divided into 2 branches. The first branch consisted of Ateng Super and C 47 varieties with a coefficient value of 0.81. In contrast, the second branch was the P 88 variety with a coefficient value of 0.758.Keywords: characteristics, varieties, arabica coffee, morpholog

Design of a self-leveling cam mechanism for a stair climbing wheelchair

This paper presents a new version of Wheelchair.q, a wheelchair with stair climbing ability. The wheelchair is able to climb single obstacles or staircases thanks to a hybrid wheel-leg locomotion unit with a triple-wheels cluster architecture. The new concept presented in this work represents an improvement respect to previous versions. Through a different arrangement of functional elements, the wheelchair performances in terms of stability and regularity during movement on stair have been increased. In particular, attention has been paid to ensure a regular and comfortable motion for the user during stair climbing operation. For this reason, a cam mechanism has been introduced and designed with the aim to compensate the oscillation generated on the wheelchair frame by the locomotion unit rotation. A design methodology for the cam profile is presented. Moreover, a parametric analysis on the cam profile and on the mechanism dimensions has been conducted with the aim to find a cam profile with suitable dimensions and performances in terms of pressure angle and radius of curvature

Meter-scale spark X-ray spectrumstatistics

X-ray emission by sparks implies bremsstrahlung from a population of energetic electrons, but the details of this process remain a mystery. We present detailed statistical analysis of X-ray spectra detected by multiple detectors during sparks produced by 1 MV negative high-voltage pulses with 1 $\mu$s risetime. With over 900 shots, we statistically analyze the signals, assuming that the distribution of spark X-ray fluence behaves as a power law and that the energy spectrum of X-rays detectable after traversing $\sim$2 m of air and a thin aluminum shield is exponential. We then determine the parameters of those distributions by fitting cumulative distribution functions to the observations. The fit results match the observations very well if the mean of the exponential X-ray energy distribution is 86 $\pm$ 7 keV and the spark X-ray fluence power law distribution has index -1.29 $\pm$ 0.04 and spans at least 3 orders of magnitude in fluence

Stair-climbing wheelchair.q05: from the concept to the prototype

In this paper, an electric stair-climbing wheelchair, named wheelchair.q05, able to move on flat ground and to climb stairs, is presented. The proposed solution has been developed through a series of studies and designs, all based on a smart hybrid triple leg-wheel locomotion unit. The stability of the device is guaranteed by a rear support of a pair of pivoting wheels during motion on flat ground, and by the support of an idle track, when climbing on or going down stairs. By means of mechanisms and actuators, it is possible to change the configuration of the wheelchair, from the flat ground motion to the stair climbing configuration