A Trade-off Analysis of Energy Detectors and Partitioned Search for Primary Detection

Cognitive radios aim to coexist in the unused spectrum bands which are licensed to primary users without harming the primary transmission/reception. For a cognitive radio, it is important to detect the band in which the primary is operating as fast as possible and with high reliability in order to adapt its transmission. In this work, we propose P-partitioning method in combination with energy detectors for the search of the band that the primary user is operating. In the P-partitioning method, the spectrum bands are categorized into P groups and the group that the primary band belongs to is detected in a recursive fashion. The energy detector operates on each group and the test statistics is the total energy received in the bands belonging to the group. The proposed search technique has detection time PlogP(N), where N is the number of bands in the spectrum. When P = N, the proposed scheme is equivalent to linear search with detection time N. We study the performance of the proposed scheme for a single non-cooperative radio and also for multiple cooperating radios. For a single cognitive radio, we provide an upper bound on the probability of correct detection which presents two different regimes of operation. In the low SNR regime, although it is counter-intuitive the partitioning improves the probability of detection. This is due an averaging effect when the signal energy in different bands are accumulated to obtain the energy contribution from a group. In the high SNR regime, performance degrades with partitioning. In addition, we observe that user cooperation improves the performance in the high SNR regimes

Carbon, nitrogen and fertility in biogenic and physicogenic aggregates from a soil with 10-year history of swine manure application

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Agrárias. Curso de Agronomia.O objetivo geral do trabalho foi avaliar os efeitos de diferentes fontes e doses de nutrientes nas vias de formação de agregados e fertilidade nesses agregados. Para tal, quantificaramse os teores de carbono orgânico total (COT), nitrogênio (N) e fertilidade (pH, Al, Ca, Mg, P e K) do solo em agregados biogênicos e fisiogênicos em áreas com aplicação de dejetos líquido de suínos (DLS) e cama sobreposta de suínos (CSS) sob sistema plantio direto. Após 10 anos do uso de dejetos suínos (DS) na sucessão aveia/milho, coletaram-se amostras indeformadas de solo nas camadas de 0-5 e 5-10 cm, nos tratamentos sem DS (testemunha), com aplicação de DLS e CSS em dose equivalente a uma e duas vezes a recomendação de N para o milho e aveia (DLS1X, DLS2X, CSS1X e CSS2X, respectivamente). Os agregados foram separados conforme a via de formação em biogênicos e fisiogênicos, sendo posteriormente feitas as análises químicas. A adição de DS aumentou a formação de agregados biogênicos em comparação aos fisiogênicos. A aplicação de CSS alterou os teores de COT e N em relação à testemunha e as áreas com DLS, que não se diferenciaram entre si. O uso de DLS aumentou os teores Ca (0-10 cm), K (DLS1X para 0-10 cm) e P (5-10 cm), e não alterou os teores de Mg e N, em relação à testemunha; enquanto o uso de CSS aumentou o Mg (0-5 cm), Ca, N, P e K (0-10 cm) quando comparado aos DLS e à testemunha. Os agregados biogênicos favorecem o aumento de N, P, K, Mg e COT em relação aos fisiogênicos.The objective overall of the study was to evaluate the effects of different sources and doses of nutrient at the formation vias of aggregates and fertility of these aggregates. To this end, were quantified the total organic carbon (TOC), nitrogen (N) and fertility (pH, Al, Ca, Mg, P and K), in biogenic and physiogenics aggregates, in areas with application of liquid swine manure (LSM) and deep litter (DP), in no-tillage system. After 10 years of using pig manure (PM) in succession oat/corn, collected up undisturbed soil samples in layers of 05.0 and 5-10cm in treatments without PM (control), with application of LSM and DP in dose equivalent to one and two times the N recommended for corn and oats (LSM1X, LSM2X, DP1X and DP2X, respectively). Aggregates were separated according to formation vias in biogenic and physicogenic, and chemical analyzes made later. The addition of PM increased the formation of biogenic aggregates compared to physicogenic. The application of DP changed the TOC and N compared to the control and the areas with LSM, which did not differ from each other. The use of LMS increased Ca levels (0-10 cm), K (LSM1X 0-10 cm) and P (5-10 cm), and did not change the Mg and N, compared to the control; while the use of DP increased Mg (0-5 cm), Ca, N, P and K (010 cm) compared to LSM and control. The biogenic aggregates favors the increase of N, P, K, Mg and TOC in relation to physicogenic

Exercise training and detraining process affects plasma adiponectin level in healthy and spontaneously hypertensive rats

BACKGROUND: Adiponectin levels with long-term swimming exercise have been never investigated in spontaneously hypertensive rats (SHR). OBJECTIVE: This study was aimed to investigate the effects of exercise and detraining process on the adiponectin plasma levels of spontaneously hypertensive rats (SHR) and healthy Wistar-Kyoto rats (WKY). MATERIAL AND METHODS: The rats in the exercise groups were swimming for 10 weeks, 5 days/week, one hour in a day. The detraining rats were left to be sedentary in their cages for 5 weeks after 10 weeks of exercise period. RESULTS: The plasma adiponectin levels decreased in E and SHRE groups compared to the SC and the SHR groups, respectively. In addition, blood pressure was decreased in the exercise groups vs their controls. The adiponectin level was not found to be significantly different in ED and SHRED groups compared to their controls. The blood pressure did not differ between SDC and ED groups, although in the SHRED group it was found to be lower than in SHRSD group rats. CONCLUSION: The results of this study showed that exercise reduced plasma levels of adiponectin in healthy and spontaneously hypertensive rats. However, this difference disappeared at the end of the training processes. Our results suggest, that changes in plasma adiponectin levels are not responsible for changes in blood pressure

Analysis of attitudes of Turkish citizens towards the effect of European Union membership on the economic, political, and cultural environment

Author's OriginalPrevious studies on Turkey’s possible accession to the European Union have mostly focused on the level of support for membership as expressed by Turkish citizens. The purpose of this paper is to shed some light on the specific expectations and perceptions of the Turks about the EU membership process, focusing on economic development, democratic progress, economic and political stability, and cultural influence. In both the focus group studies and the final survey, the authors targeted people who have some knowledge about the EU accession process and EU membership, namely, academics and business people.Aybar, C., Mergen, A., Perotti, V., & Reid, D. (2007). Analysis of Attitudes of Turkish Citizens towards the Effect of European Union Membership on the Economic, Political, and Cultural Environment. Turkish Studies, 8(3), 329-348. doi:10.1080/1468384070148908

Evolutionary aspects in evaluating mutations in the melanocortin 4 receptor

More than 70 missense mutations have been identified in the human melanocortin 4 receptor (MC4R), and many of them have been associated with obesity. In a number of cases, the causal link between mutations in MC4R and obesity is controversially discussed. Here, we mined evolution as an additional source of structural information that may help to evaluate the functional relevance of naturally occurring variations in MC4R. The sequence information of more than 60 MC4R orthologs enabled us to identify residues that are important for maintaining receptor function. More than 90% of all inactivating mutations found in obese patients were located at amino acid positions that are highly conserved during 450 million years of MC4R evolution in vertebrates. However, for a reasonable number of MC4R variants, we found no correlation between structural conservation of the mutated position and the reported functional consequence. By re-evaluating selected mutations in the MC4R, we demonstrate the usefulness of combining functional and evolutionary approaches

Ultra-Low Frequency Waves at Middle Latitudes During Substorms: Observations and Modeling

This doctoral dissertation presents the results of investigation of the Ultra-Low Frequency (ULF) waves at middle latitudes during substorms. The dissertation consists of two major parts, observations and simulations. The research in this dissertation proposes that the main role in the generation of ULF waves at middle latitudes during substorm belongs to the plasmapause. The first part of the dissertation presents results of the data analysis of 84 intense substorm events as well as an overview of space observation programs such as CRRES, Van Allen Probes and DMSP. Data used in this study are from the ACE satellite taken measurements in the solar wind and ground magnetometers at high (L = 5.76), middle (L = 2.46), and low ( L = 1.87) latitudes. We estimated correlations between fluctuations of the magnetic field measured at all sources and correlations between fluctuations of the solar wind ion density and the magnetic field at high, middle, and low latitudes. The main conclusion is that the dominant frequencies of oscillations of the magnetic field are in the range of 0.45-0.80 mHz across all the sources, and 0.45-0.55 mHz are the most common ones across all sources. Among 84 events, 33 events have a good match of dominant frequencies in power spectral density; 43 events have a cross-correlation of r \u3e 0.2 of the detected waves across all sources; and 22 events feature both. Also, seven out of the nine GEM events have a strong correlation between the variation of the solar wind speed and the Dst index. Therefore, the results suggest that the variations of the magnetic field in the solar wind are one of the main drivers of the ULF magnetic field pulsations with frequencies less than 1 mHz detected in three different latitudes during substorms. The novelty of this research is that it is among the first studies that investigate the ULF waves in the solar wind and at high, middle and low latitudes on the ground. The research also shows that in the amplitude of the ULF waves observed at low latitudes is higher compare with the amplitude of ULF waves detected at middle latitudes. This feature suggests that these waves are generated by the disturbances in the ring current, which are driven by the disturbances of the magnetic field in the solar wind. The coupling between the solar wind and the inner magnetosphere of the Earth can occur at the night side and on the day side of the Earth. The exact mechanism of coupling between the oscillations in the solar wind and the magnetic pulsations detected in these parts of the magnetosphere is discussed. In the second part of the dissertation, we also provide the theoretical background of the Field-Line Resonance and Ionospheric Feedback Instability as well as the methodology for the 2D RMHD two-fluid simulations at mid latitudes. The results from the numerical study presented in the dissertation demonstrate that the plasmapause plays a very important role in the generation of ultra-low frequency waves detected with ground magnetometers at middle latitudes. The strong gradient in the plasma density associated with the plasmapause converts the electromagnetic energy of the fast magnetosonic waves propagating across the magnetic field to the energy of the field-aligned surface Alfvén waves. The efficiency of this mode conversion depends on the parameters of the plasmapause. In particular, the time-dependent simulations of the two-fluid MHD model show that the amplitude of the surface waves is linearly proportional to the gradient of the plasma density and the magnitude of the variation of the density across the plasmapause. The research uses the observations from the ground magnetometers at Palmer station in Antarctica to identify the frequency of the driver and frequencies of the waves generated by the ionospheric feedback instability. It also uses the observations of the plasma density conducted by the the NASA Van Allen Probes satellite in the equatorial magnetosphere on the same date. The satellite observations confirm that during substorms the plasmasphere can be strongly eroded away and the plasmapause moves to middle latitudes. The model uses the observed frequency of 1.1 mHz to drive the surface waves on the plasmasphere. The simulations show that the large scale electric field modulated with this frequency drives the ionospheric feedback instability generating waves with frequencies \u3c 25 mHz. The waves with the same frequencies are also observed in the measurements of the Palmer magnetometer. The numerical results and the ground observations also reveal waves with the frequencies in the range 0.5-1.0 Hz, which correspond to the frequencies of the ionospheric Alfvén resonator. This is a very expectable outcome because the main driver of the waves inside the IAR is the same ionospheric feedback instability as the one used in this study to drive the waves in the global magnetospheric resonator. The simulations also demonstrate that the instability develops quite efficiently from the small-scale ionospheric irregularities associated with the numerical noise in the simulations which can be considered as a proxy for the random thermal fluctuation of the plasma density in the real ionosphere