Application of Memristors in Microwave Passive Circuits

The recent implementation of the fourth fundamental electric circuit element, the memristor, opened new vistas in many fields of engineering applications. In this paper, we explore several RF/microwave passive circuits that might benefit from the memristor salient characteristics. We consider a power divider, coupled resonator bandpass filters, and a low-reflection quasi-Gaussian lowpass filter with lossy elements. We utilize memristors as configurable linear resistors and we propose memristor-based bandpass filters that feature suppression of parasitic frequency pass bands and widening of the desired rejection band. The simulations are performed in the time domain, using LTspice, and the RF/microwave circuits under consideration are modeled by ideal elements available in LTspice

Other profitable activities on family agricultural holdings according to their economic size

In the paper will be emphasized the importance of the other profitable activities (OPA) on the family agricultural holdings, according to their economic size within the territory of Republic of Serbia, with special focus on the Vojvodina Region. Economic size of the agricultural holding is recognized by the value of its total standard output (SA). Other profitable activities related to the agricultural holdings include incomes from agricultural products sale, rural tourism, fishery, etc., whether they are performed on or outside the holding. Other profitable activities that are not related to agricultural holdings include activities that do not consume resources of the holding, but only the labor, as like in previous case they may be carried on, or outside the holding. According to gained results, average economic size of the holding in the Republic of Serbia is 5.939 EUR, while the realized economic value on the family agricultural holdings (FAH) is 4.990 EUR. Census of Agriculture in 2012 showed that the highest average economic size of the agricultural holdings has a Vojvodina Region (12.032 EUR), what is 3,5 times higher than the value achieved in other regions. From the total sum of 631.552 agricultural holdings in the Republic of Serbia (family agricultural holdings (FAH), as well as legal entities (LE) and entrepreneurs) only 78.301 holdings possess DPA that are in relation to the holding (where 21% of them are within the economic class in range of 4.000 - 7.000 EUR). At the level of the Vojvodina Region, in total there were registered 147.624 agricultural holdings (AH), where 8.405 of them have OPA in relation to the holding (13,6% are within the class of economic sizes 100.000 and more EUR)

Distinct subsets of unmyelinated primary sensory fibers mediate behavioral responses to noxious thermal and mechanical stimuli

Behavioral responses to painful stimuli require peripheral sensory neurons called nociceptors. Electrophysiological studies show that most C-fiber nociceptors are polymodal (i.e., respond to multiple noxious stimulus modalities, such as mechanical and thermal); nevertheless, these stimuli are perceived as distinct. Therefore, it is believed that discrimination among these modalities only occurs at spinal or supraspinal levels of processing. Here, we provide evidence to the contrary. Genetic ablation in adulthood of unmyelinated sensory neurons expressing the G protein-coupled receptor Mrgprd reduces behavioral sensitivity to noxious mechanical stimuli but not to heat or cold stimuli. Conversely, pharmacological ablation of the central branches of TRPV1+ nociceptors, which constitute a nonoverlapping population, selectively abolishes noxious heat pain sensitivity. Combined elimination of both populations yielded an additive phenotype with no additional behavioral deficits, ruling out a redundant contribution of these populations to heat and mechanical pain sensitivity. This double-dissociation suggests that the brain can distinguish different noxious stimulus modalities from the earliest stages of sensory processing

Descending serotonergic facilitation and the antinociceptive effects of pregabalin in a rat model of osteoarthritic pain

Background: Descending facilitation, from the brainstem, promotes spinal neuronal hyperexcitability and behavioural hypersensitivity in many chronic pain states. We have previously demonstrated enhanced descending facilitation onto dorsal horn neurones in a neuropathic pain model, and shown this to enable the analgesic effectiveness of gabapentin. Here we have tested if this hypothesis applies to other pain states by using a combination of approaches in a rat model of osteoarthritis (OA) to ascertain if 1) a role for descending 5HT mediated facilitation exists, and 2) if pregabalin (a newer analogue of gabapentin) is an effective antinociceptive agent in this model. Further, quantitative-PCR experiments were undertaken to analyse the alpha(2)delta-1 and 5-HT3A subunit mRNA levels in L3-6 DRG in order to assess whether changes in these molecular substrates have a bearing on the pharmacological effects of ondansetron and pregabalin in OA.Results: Osteoarthritis was induced via intra-articular injection of monosodium iodoacetate (MIA) into the knee joint. Control animals were injected with 0.9% saline. Two weeks later in vivo electrophysiology was performed, comparing the effects of spinal ondansetron (10-100 mu g/50 mu l) or systemic pregabalin (0.3-10 mg/kg) on evoked responses of dorsal horn neurones to electrical, mechanical and thermal stimuli in MIA or control rats. In MIA rats, ondansetron significantly inhibited the evoked responses to both innocuous and noxious natural evoked neuronal responses, whereas only inhibition of noxious evoked responses was seen in controls. Pregabalin significantly inhibited neuronal responses in the MIA rats only; this effect was blocked by a pre-administration of spinal ondansetron. Analysis of alpha(2)delta-1 and 5-HT3A subunit mRNA levels in L3-6 DRG revealed a significant increase in alpha(2)delta-1 levels in ipsilateral L3&4 DRG in MIA rats. 5-HT3A subunit mRNA levels were unchanged.Conclusion: These data suggest descending serotonergic facilitation plays a role in mediating the brush and innocuous mechanical punctate evoked neuronal responses in MIA rats, suggesting an adaptive change in the excitatory serotonergic drive modulating low threshold evoked neuronal responses in MIA-induced OA pain. This alteration in excitatory serotonergic drive, alongside an increase in alpha(2)delta-1 mRNA levels, may underlie pregabalin's state dependent effects in this model of chronic pain

Novel waveguide filters using T-shaped resonators

An enhanced waveguide E-plane bandpass filter using T-shaped resonators is presented. Characteristics of the proposed filter structure are analysed and investigated. The proposed filter with 4.5 % bandwidth is designed at 9.45 GHz, fabricated and tested. Its performance is evaluated through measurements, the experimental results obtained show that the proposed bandpass filter structures improve selectivity and size compared with those obtained using a conventional E-plane filter structure. A size reduction of more than 12 % was achieved and selectivity performance improved by more than 60 dB

Design of open-loop dual-mode microstrip filters

This paper presents the design of compact second-order bandpass ¯lters based on dual-mode open-loop resonator. A ¯lter design procedure is provided to facilitate the design process. The paper also describes the nature of the inherent transmission zero associated with the structure and presents a method of generating two additional zeros for improving stop-band performance. Finally, a ¯lter design example is presented to validate the argument

EVALUATION OF REALIZED INVESTMENTS IN AGRICULTURE IN AREA OF UPPER DANUBE REGION

Special natural reserve „Upper Danube“ is protected natural area I category, which extends on the left bank of Danube river in Republic Serbia. The reserve is part of large marshland complex and represents one of the last large floodplains on the ground of the European continent. Getting into consideration the natural conditions, production resources, the structure of agricultural production and related activities, and environmental, infrastructural and social conditions in which these economic activities take place, formed the basis for research on the Upper Danube. For research purposes, this field is viewed in the broader context of the administrative area includes the city of Sombor and Municipalities: Apatin, Bač and Bačka Palanka. On the other hand, from the perspective of the enlargement process of the European Union (EU), derived for our country and the importance of capital investment for sustainable development imposed by the need to analyze the economic efficiency of investment in agriculture. Accordingly, the research activity is conducted within the boundaries of the analysis of investments in agriculture in the Upper Danube

PREFERENCES OF WINE CONSUMERS ON SERBIAN MARKET

Wine, as worldwide known beverage left deep traces in tradition of many nations, and way it is consumed, very often reflects culture, customs and lifestyles of local communities. Beside health benefits, wine is very often symbol and sign of prestige, especially within wealthy consumers, and its’ consumption is influenced mostly by tradition, confession, habits and level of life standard. General recognition of wine initiated poll research survey during 2011 with basic goal to perceive factors that determine demand and consumption of wine in Republic of Serbia. In other words, survey tried to establish what are the preferences, motives, and consumer attitudes when buying a wine in domestic market. Gained results could represent useful database to wineries and wine importers who can based on that estimate current market potential and their products niche in domestic market