Efecto de los cotiledones y el uso de semilla híbrida en brócoli (Brassica oleracea var. italica L.)

p.177-187Los objetivos de este ensayo fueron (a) cuantificar la acumulación de biomasa en función de la eliminación parcial o total de los cotiledones tempranamente durante la fase de propagación en una bandeja multicelda y (b) evaluar el efecto sobre dos materiales genéticos (variedad de polinización abierta o híbridos F1) durante el ciclo primaveral - estival en el cinturón hortícola de la ciudad de Mar del Plata. Los resultados indican que la falta total o parcial de cotiledones funcionales durante la expansión de las primeras hojas verdaderas de la planta puede afectar la generación de biomasa fotosintética luego del trasplante. Las diferencias a favor del uso de híbridos F1 se amplificaron bajo condiciones de temperatura supraópticas

Notes on the anatomy and phylogenetic position of Eremias ercolinii Lanza & Poggesi 1975 (Reptilia Lacertidae)

Detailed examination of the only known specimen of Eremias ercolinii Lanza & Poggesi 1975 shows that it has affinities within the Ophisops-Mesalina clade and, on present evidence, is best regarded as a member of Mesalina Gray 1838. However, its exact phylogenetic position will only be confirmed when more material becomes available. Limb proportions and scale form suggest that Mesalina ercolinii probably spends time in low, dense vegetation

Thermoresponsive Ionic Liquid/Water Mixtures: From Nanostructuring to Phase Separation

The thermodynamics, structures, and applications of thermoresponsive systems, consisting primarily of water solutions of organic salts, are reviewed. The focus is on organic salts of low melting temperatures, belonging to the ionic liquid (IL) family. The thermo-responsiveness is represented by a temperature driven transition between a homogeneous liquid state and a biphasic state, comprising an IL-rich phase and a solvent-rich phase, divided by a relatively sharp interface. Demixing occurs either with decreasing temperatures, developing from an upper critical solution temperature (UCST), or, less often, with increasing temperatures, arising from a lower critical solution temperature (LCST). In the former case, the enthalpy and entropy of mixing are both positive, and enthalpy prevails at low T. In the latter case, the enthalpy and entropy of mixing are both negative, and entropy drives the demixing with increasing T. Experiments and computer simulations highlight the contiguity of these phase separations with the nanoscale inhomogeneity (nanostructuring), displayed by several ILs and IL solutions. Current applications in extraction, separation, and catalysis are briefly reviewed. Moreover, future applications in forward osmosis desalination, low-enthalpy thermal storage, and water harvesting from the atmosphere are discussed in more detail

Blocking CD248 molecules in perivascular stromal cells of patients with systemic sclerosis strongly inhibits their differentiation toward myofibroblasts and proliferation: A new potential target for antifibrotic therapy

Background: Fibrosis may be considered the hallmark of systemic sclerosis (SSc), the end stage triggered by different pathological events. Transforming growth factor-β (TGF-β) and platelet-derived growth factor BB (PDGF-BB) are profibrotic molecules modulating myofibroblast differentiation and proliferation, respectively. There is evidence linking CD248 with these two molecules, both highly expressed in patients with SSc, and suggesting that CD248 may be a therapeutic target for several diseases. The aim of this work was to evaluate the expression of CD248 in SSc skin and its ability to modulate SSc fibrotic process. Methods: After ethical approval was obtained, skin biopsies were collected from 20 patients with SSc and 10 healthy control subjects (HC). CD248 expression was investigated in the skin, as well as in bone marrow mesenchymal stem cells (MSCs) treated with TGF-β or PDGF-BB, by immunofluorescence, qRT-PCR, and Western blotting. Finally, in SSc-MSCs, the CD248 gene was silenced by siRNA. Results: Increased expression of CD248 was found in endothelial cells and perivascular stromal cells of SSc skin. In SSc-MSCs, the levels of CD248 and α-smooth muscle actin expression were significantly higher than in HC-MSCs. In both SSc- and HC-MSCs, PDGF-BB induced increased expression of Ki-67 when compared with untreated cells but was unable to modulate CD248 levels. After CD248 silencing, both TGF-β and PDGF-BB signaling were inhibited in SSc-MSCs. Conclusions: CD248 overexpression may play an important role in the fibrotic process by modulating the molecular target, leading to perivascular cells differentiation toward myofibroblasts and interfering with its expression, and thus might open a new therapeutic strategy to inhibit myofibroblast generation during SSc

Bidirectional Hybrid DC Circuit Breaker with Zero Voltage and Current Switching for Radar Power System

This paper proposes a novel zero-voltage switching (ZVS) and zero-current switching (ZCS) based hybrid DC circuit breaker for a radar power system. Long-range radars demand huge power, in the order of hundreds of kW. Radar's phased array antenna houses a large number of electronic devices and works primarily on a DC power supply. Typically, military systems are required to have the highest operational reliability, as a result, electrical system protection plays a crucial role. A high power 310 V DC electrical power grid in radar carries hundreds of amperes of current under nominal operating conditions, results in significant fault current due to very low impedance, and demands a very fast fault interruption device. This paper proposes and demonstrates the complete operation of a hybrid DC circuit breaker topology for radar applications. The proposed DC circuit breaker employs a mechanical switch that carries the entire current during the nominal operating conditions, and a Power Electronic Module (PEM) connected in parallel helps in diverting the fault current from the main path. Fault current transfers to the PEM branch in a fraction of a second (5μs), which ensures faster load-side isolation. During the fault interruption process, mechanical switch contact opening experiences both ZVS and ZCS features, resulting in arcless operation, and also helps in faster contact separation. The ZVS and ZCS feature greatly improve the reliability of the mechanical switch. The proposed concept does not involve any capacitors and corresponding pre-charging circuits for the ZVS/ZCS features. The proposed DC circuit breaker is analyzed theoretically, and also by simulations in LTspice. Additionally, an experimental prototype with a DC system rating of 310 V - 10 A is developed to experimentally validate the performance of the proposed breaker topology. The paper also presents a detailed design and comparative analysis, along with a discussion on the limitations of the proposed DC circuit breaker, and the scope for improvements

An inverse validation for detecting pipe leaks with a TDR-based method

Recently, an innovative system based on time domain reflectometry (TDR) for the individuation of leaks in underground pipes has been proposed and validated. Starting from the results obtained so far, the present works aims at further investigating the practical applicability of the aforementioned system. In particular, the goal of this work is to assess the system in the detection of two close leaks (i.e. leakages that may occur on the same length of pipe). To this purpose, an experimental setup was arranged: two "leakage conditions" were imposed, and the position of the leaks were considered as unknown and calculated through the dedicated developed algorithm. Results show that, differently from traditional leak detection methods (in which the presence of a leak may "mask" the presence of other leaks), the TDR-based system successfully individuates and correctly localizes the presence of two leaks

Latest Advancements in SSVEPs Classification for Single-Channel, Extended Reality-based Brain-Computer Interfaces

This work details the latest advancements on a single-channel, reactive Brain-Computer Interfaces developed at the Interdepartmental Research Center in Health Management and Innovation in Healthcare (CIRMIS) of the University of Naples Federico II. The proposed instrumentation is based on Extended Reality (XR) and exploits the acquisition and classification of the Steady-State Visually Evoked Potentials (SSVEPs). In particular, an XR headset is employed for generating the flickering stimuli necessary to the SSVEP elicitation. The users brain signals are captured by means of a highly wearable and portable electroencephalografic acquisition unit, which is connected to a portable processing unit in charge of processing in real time the incoming data. In this way, a deeper interaction between users and external devices with respect to traditional architectures is guaranteed. The classification capability of the proposed instrument has been significantly improved over the years. Currently, in fact, a classification accuracy up to 90 % is obtained with at least 2 s of acquisition time