In this report, we introduce cooperative spectrum sensing using orthogonal space time block coding (OSTBC) in order to achieve cooperative diversity in the cognitive radios (CRs) network. Transmit diversity or gain is achieved by introducing more than one antenna on the transmitter and receiver side, but in small electronic mobile devices it looks impractical. The signals received from the primary users (PUs) are amplified by the cognitive relays and further forwarded to the cognitive controller where decisions are made on the basis of the information collected from each cognitive relay. The cooperative relaying protocol used here in cognitive relays is based on an amplifying-forward (AF) scheme. Alamouti scheme in OSTBC has been proposed to achieve better detection performance in CR network. The energy detector performance is analyzed over an independent Rayleigh fading channel. In CR network the secondary user (SU) shares PU's frequency band if it fi nds PU is not in its vicinity. The SU starts using the licensed band and leaves the band as soon as it finds the PU is present or going to use the same band. The detection of the spectrum holes by CRs has to be more agile and intelligent. The main objective of the CRs network is to use the free holes without causing any interference to the PUs. The energy detection technique is simple and outperforms other sensing techniques in cooperative cognitive radio networks. The energy detector collects information from different users, compares it with a certain prede fined threshold () value and then makes a fi nal decision. Detection and false alarm probabilities are derived and manipulated using OSTBC on PU and SU through AF protocol in cooperative communication. The performance of the system is analyzed with single and multiple relays and with and without direct path between the PUs and SUs. Maximum ratio (MRC) and selection combining (SC) schemes are used in energy detector and the results are compared with and without direct link between PU and SU. The analysis is performed by placing the relay close to the PUs. Our results are processed and validated by computer simulation.

People who endure horrific, life-threatening experiences are at risk for developing post-traumatic stress disorder (PTSD). However, only about 25% of all individuals who experience trauma develop PTSD. Recent research indicates that the presence of certain physiological conditions, such as reduced cortisol and parasympathetic inhibition, during trauma may increase one's susceptibility to developing PTSD. Thus, I attempted to develop a novel animal model of PTSD and test the hypothesis that reduced adrenal and parasympathetic activity during stress would exacerbate its long-term effects on behavior.In Experiment One, adult male rats were exposed to two stress sessions, each involving one hour of immobilization plus cat exposure. Before each session, rats were injected with vehicle, metyrapone, AF-DX 116, or both drugs. The second session occurred 10 days after the first and served to model a traumatic flashback. Stressed rats endured unstable housing conditions throughout t he experiment to add an element of daily anxiety. Three weeks after the second session, all rats underwent a battery of tests to examine the lasting effects of stress on physiology and behavior. The results indicated that stressed rats exhibited heightened anxiety on the elevated plus maze, an exaggerated startle response, and greater blood pressure, relative to controls. Moreover, metyrapone, when combined with stress, led to significant short- and long-term spatial memory impairments. Experiment Two assessed the effects of the same stress paradigm on rats' sensitivity to yohimbine, an alpha-2 adrenergic receptor antagonist. Yohimbine induces flashbacks and panic attacks in patients with PTSD; thus, I hypothesized that stressed rats would react abnormally to this agent. Stressed and unstressed rats were administered vehicle or yohimbine (1 mg/kg) 30 min prior to behavioral testing. The results indicated that stressed rats were hyperresponsive to yohimbine, as evidenced by a greater su ppression of rearing, greater avoidance of the center of the open field, and a greater suppression of activity on the elevated plus maze, relative to controls. Collectively, the findings of these studies indicate that uncontrollable and unpredictable psychological stress produces lasting changes in the physiology and behavior of rats that resemble symptoms commonly observed in people with PTSD.

This dissertation evaluated nutritional approaches such as the addition of betaine, prebiotics, probiotics, transitional metabolic substrates, and β-mercaptoacetate (MAA; a compound which inhibits β-oxidation) to the diet of lactating dairy cows to determine their impact on physiological, metabolic, hormonal and production responses during thermal stress. The first objective was to evaluate the use of an organic osmolyte, betaine to reduce the impact of heat stress (HS). Cows were fed either 0 (control; CON), 57 mg/kg BW (mid) or 114 mg/kg (high; HI) body weight (BW) betaine and subjected to thermoneutral (TN) and HS conditions. There was an increase in milk yield during TN with HI betaine over controls (P< 0.01), but the advantage was lost during HS. Plasma glucose increased during HS in HI dose cows compared to control (P < 0.01) as did plasma insulin (P = 0.01). Betaine increased milk production during TN and plasma glucose in HS, but did not improve the HS response. Objective two evaluated the use of a probiotic or direct fed microbial (DFM), Calsporin (Bacillus subtilus C-3102) to decrease the effects of HS in dairy cows. We hypothesized that feeding Calsporin prior to and during HS would reduce pathogenic strains of bacteria, maintain commensal microbes, and improve ruminal anaerobic fermentation resulting in improved milk yield (MY). Milk yield was numerically increased (1.26 kg, P = 0.11) in cows fed Calsporin during TN but was reduced under HS (-2.67 kg, P < 0.01) and milk protein content was decreased (P = 0.05). The DFM tended to decrease somatic cell count (SCC) across periods (P = 0.07). Calsporin addition to the diet did not affect respiration rates and was associated with higher rectal temperature at 1800 in HS (P = 0.02). The expression of heat shock protein 27 (HSP27) was decreased with Calsporin treatment (P = 0.03) and in both HS and TN. The fecal microbial count did not change with the exception of the Calsporin strain in treated animals (P < 0.01). The third objective was to feed OmniGen-AF (OG) to dairy cows before and during thermal stress. We hypothesized that feeding OG to HS dairy cows will improve the immune response, and decrease production losses associated with HS. Cows fed OG maintained lower SCC compared to control (P < 0.01) during the recovery period. We did not detect differences between groups in serum calcium while serum non-esterified fatty acid (NEFA) concentrations (P = 0.10) tended to be greater in OG fed cows across the Agricultural Research Center (ARC) portion including HS. Serum Adrenocorticotropic hormone (ACTH) levels were greater in OG cows (P<0.0001) across all sample days. Feeding OG reduced the HS response including serum Cortisol. The final study measured the effects of the metabolic substrate β-hydroxybutyrate (BHB) during HS on feed intake and metabolites. Under TN conditions the cows received a bolus dose of BHB and dry matter intake (DMI) and metabolites were measured. The second part of this study used a bolus of MAA to limit the up-stream production of acetyl-CoA available for ketogenesis by inhibiting ß-oxidation. We proposed that dosing lactating dairy cows with BHB would decrease DMI, increase plasma insulin, decrease NEFAs and increase skin temperature by vasodilatation. The same cows were then subjected to HS and dosed with saline and MAA on different test days. The infusion of BHB increased skin temperature (time 0.5, 1, 2, 3 and 4°C r² =0.98 with serum BHB) and decreased serum NEFA levels (P < 0.01). There was no change in mean DMI, glucose or insulin. The bolus of MAA decreased feed intake, vaginal temperature, and insulin. There was an increase in serum BHB with the initial dose of MAA and an initial decrease in serum glucose (P < 0.0001) with MAA. Serum glucose increased as insulin decreased with MAA. The infusion of BHB did not alter feed intake in this study despite high plasma levels of BHB.

Polymer waveguides present a potentially low cost alternative to electronics in communication systems. Polymers offer relatively straightforward and economical fabrication when compared to conventional materials. In this study, a fabrication process for Bragg gratings in polymer waveguides was developed. Waveguides were designed using finite-element analysis, patterned via e-beam lithography, and a detailed fabrication method was developed. Surface-Plasmon Resonance (SPR) is a widely accepted method for biological and chemical sensing. Measurement of bulk refractive index changes and specific surface binding is a crucial part in any biosensing. Design and fabrication of a novel self-referencing SPR sensor is described and its functionality is tested.

Thin films of Teflon AF have been directly patterned by electron-beam lithography without the need for post exposure chemical development. The relationship between pattern depth and exposure dose was found to be linear over a wide range of doses. Pattern depth was also observed to be dependent on initial film thickness. Teflon AF can be directly patterned at doses similar to typical e-beam resists. High resolution features as small as ~200 nm have been resolved. FTIR measurements revealed that CF3 and fluorinated dioxole groups play a significant role in the patterning mechanism. Teflon AF films also exhibited an increase in refractive index upon exposure to the electron-beam. This property has been exploited in waveguiding applications. Waveguides in Teflon AF were patterned using direct electron beam lithography technique. Waveguides were clearly visible to the naked eye. Characterization in the visible region showed evidences of light guiding through the waveguides. However light could not cross the entire chip. Characterization in the infrared region revealed the slab mode even though individual waveguides were not detected.

BAGGRUND: Antibiotikaresistens udgørentrussel mod folkesundheden. Antibiotikabruger hoveddrivekraften bag resistensudviklingen.Restriktiv antibiotikabrugi overens-stemmelse med de gældende retningslinjerer derfornødvendig. Tarmfloraenpåvirkes af antibiotika oghar betydning for helbredet.Den salutogene teori er et veletableretkonceptindenfor Public Health. Oplevelse af sammenhæng (OAS)udgør et centralt koncept indenfor den salutogene teori, afspejler en persons syn på livet og kapacitet til at respondere på stressfyldte situationerog indeholder komponenterne begribelighed, håndterbarhed og meningsfuldhed.OASudgøret værdifuldt værktøj ved problemstillinger, hvor målet er ”compliant”adfærd.Det kunne tænkes,at hvis befolkningen og lægerne manglede OAS vedrestriktiv antibiotikabrug, kunne dette bidrage til at derescompliance til retningslinjerne, der anbefaler forsigtig antibiotikabrug ikke var optimal. FORMÅL: At formulere forslag til, hvordan forsigtig antibiotikabrug kunne fremmes ved at optimere OAS. Baggrundener litteratur, der belyser (i) befolkningens og lægernesholdninger overfor antibiotika og antibiotikaresistens i Norden og (ii) antibiotikas påvirkning af tarmfloraen og mulige helbredsmæssige konsekvenser.Det undersøges om der er grund til at ændre holdning overfor antibiotika,hvilke faktorerderfremmer og hæmmer forsigtig antibiotikabrug og hvordan OASkunne optimeres. METODE: Litteraturstudie efter struktureret litteratursøgning i PubMed og PsychINFO. RESULTATER: Antibiotika betragtes som noget beskyttende. Det kan ikke udelukkes, at antibiotika ved at påvirke tarmfloraen, kan have negative konsekvenser for helbredet.Viden, vaner og kommunikation har betydning for hvordan antibiotika bruges og hvorvidt forsigtig antibiotikabrug opleves begribelig og håndterbar.Læger kan ved ordination af antibiotika opleve en konflikt mellem patienten,der skal behandles bedst muligtog samfundet, hvor tiltagende antibiotikaresistens skal begrænses. Dette kan være én grund til at forsigtig antibiotikabrug ikke opleves meningsfuld. KONKLUSION: Forsigtig antibiotikabrug kunne fremmes ved atfremme velfungerende kommunikationog ved atbruge antibiotikas påvirkning af tarmfloraenog mulige helbredsmæssige konsekvenser som motivation. Hensigtsmæssige vaneri sammen-hæng med antibiotikabrug skal støttes og uhensigtsmæssige vaner om lægges. Her kunnelæger følges af en mikrobiolog for en dag / BACKGROUND:Drug resistance resulting from the overuse of antibiotics poses a threat to public health. Consequently, antibiotics must be used more cautiously.Intestinal flora is important to health and antibiotics can disrupt intestinal flora. Salutogenic theory is a well-established concept in public health. Sense of coherence (SOC), which is a key concept insalutogenic theory, reflects a person ́s lifeviewand capacity to respond to stressful situations, includes three components: comprehensibility, manageability and meaningfulness. SOC is a valuable tool for problems that target “compliant” behavior. Lack of SOC in both physicians and the general public may contribute to poor compliance to current guidelines that recommend restricting the use of antibiotics. AIM: The study aimed to formulate proposals for promoting the prudent use of antibiotics by optimizing SOCbased on literature that illustrates(i) the attitudes of the general public and doctors regarding antibiotics and antibiotic resistance in Scandinavia and (ii) the influence and possible health consequences of antibiotics on intestinal flora. It is discussed whether there are reasons for looking at antibiotics in a different way, which factors that facilitate or hinder prudent antibiotic use and how SOC could be optimized. METHODS: A literature study aftera structured search of the PubMed and Psych INFOdatabases. RESULTS: Although antibiotics are generally considered protective, their effect on intestinal flora may have adverse health consequences. Knowledge, habits and communication affect how antibiotics are used and whether prudent antibiotic use is experienced comprehensible and manageable. Doctors may experience conflict when prescribing antibiotics between treating the patient in the best possible manner and the need to limit such treatment to protect the community from increased resistance to antibiotics. Doctors ́wish to guarantee that their patients receive the best possible treatment might be one reason why they do not adhere to guidelines that recommend more restrictive use of antibiotics. Doctors do not consider the cautious use of antibiotics as meaningful. CONCLUSION: Careful antibiotic use could be promoted by using the influence of antibiotics on intestinal flora as motivational strategy;promoting effective communication and supporting appropriate and unlearn undesirable habits related to antibiotic use. A possible approach would be teaming physicians with a microbiologist for a day / <p>ISBN 978-91-982282-8-1</p>

Akademisk avhandling--Tekniska fakulteten--Lund, 1988. / Résumé en anglais.

Thesis (Ph. D.)--Universität Zürich. / Includes bibliographical references (p. i-iii).

Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The phenomenon of cavitation on the metal surface causes erosion decaying components in operation, in particular the blades of turbines for power generation, accounting for maintenance costs and losses in electricity generation resulting from periodic stops. The blades of these turbines, particularly those manufactured by C-Mn steel (carbon - manganese) are coated by arc welding for stainless steel protective order to present more uptime or longer intervals between maintenance periods. Among the materials used to coat these blades are austenitic stainless steels, and stainless steels featured in the Co and Cobased alloys (commercially Stellites). However, the latter have a high cost. Among the welding processes applied to the coating, the technique of adding cold wire (GMAW and GMAW-CW-AF) is presented as an advantageous tender in relation to other techniques currently existing special and conventional welding. Given the context, this work seeks to study, apply and evaluate the effect of alloy and austenitic stainless steel alloys Co (CoCrMo and CoCrW) deposited by GMAW-CW for the purpose of characterization, comparison, formulation and deposition of new alloys from commercial wire correlating with resistance to mass loss. The adjustments of welding technique have focused on obtaining the manufacture of coatings suitable welding parameters. The cavitation wear resistance was evaluated according to ASTM G 32, correlating microstructure and phases by optical microscopy, SEM-EDS, chemical composition and optical emission spectrometry analyzes of the phases present by XRD. The qualities of the welded surfaces have been analyzed by visual examination and Penetrant Liguid according to standard NT (Nondestructive Testing). It was found that the coatings showed good weldability without discontinuities or defects with good surface finish. In the analysis of the coatings of cobalt, the alloy H (Stellite electrode 21 and 309LSi as cold wire) and M (Stellite 6 and 309LSi electrode as cold wire) showed good performance in resistance to cavitation in similar levels of surface roughness and hardness when compared to coatings Stellites 21 and 06, made by conventional GMAW process. / O fenômeno da cavitação sobre a superfície metálica provoca à erosão que deteriora componentes em operação, em particular as pás de turbinas hidráulicas de geração de energia, sendo responsável por custos da manutenção e perdas em geração de energia elétrica decorrente das paradas periódicas. As pás dessas turbinas, em especial as fabricadas pelo aço C-Mn (carbono manganês) são revestidas por soldagem a arco por aços inoxidáveis a fim de proteção para que apresentem maior tempo de operação ou maior intervalo entre os períodos de manutenção. Entre os materiais aplicados para revestir essas pás estão os aços inoxidáveis austeníticos, e em destaque os aços inoxidáveis ao Co e as ligas à base de Co (comercialmente Stellites). No entanto, estes últimos apresentam alto custo. Entre os processos de soldagem aplicados para o revestimento, a técnica de adição de arame frio (GMAW-CW ou GMAW-AF) se apresenta como uma proposta vantajosa em relação às outras técnicas especiais de soldagem existentes atualmente e convencionais. Diante do contexto, este trabalho buscou estudar, aplicar e avaliar o efeito das ligas de aço inoxidáveis austeniticos e ligas de Co (CoCrMo e CoCrW) depositadas pelo processo GMAW-CW com a finalidade de caracterização, comparação, formulação e deposição de novas ligas a partir de arame comerciais, relacionando com a resistência à perda de massa. As adequações da técnica de soldagem têm como foco a obtenção dos parâmetros de soldagem adequados à confecção dos revestimentos. A resistência ao desgaste por cavitação foi avaliada segundo a Norma ASTM G 32, correlacionando com a microestrutura e fases por microscopia óptica, MEV-EDS, composição química por espectrometria de emissão óptica e análises das fases presentes por DRX. As qualidades das superfícies soldadas foram analisadas por análise visual e Líquido Penetrante de acordo com a norma de END (Ensaio Não Destrutivo). Verificou-se que os revestimentos apresentaram boa soldabilidade, sem descontinuidades ou defeitos, com bom acabamento superficial. Na análise dos revestimentos de cobalto, as ligas H (eletrodo Stellite 21 e 309LSi como arame frio) e M (eletrodo Stellite 6 e 309LSi como arame frio) apresentaram bom desempenho de resistência a cavitação em semelhantes níveis de rugosidade e dureza quando comparados aos revestimentos de Stellites 21 e 6, feitos pelo processo GMAW convencional. / Doutor em Engenharia Mecânica

Clean water is hard to obtain in certain areas, such as remote locations and during emergency response. Our study developed a membraneless water purification system using diffusiophoresis and tested the influence of various factors (gas pressure, liquid flow rate, etc.) on the turbidity of filtered water. The main component in the separation system is a tube-in-tube-in-tube separator. The inner tube and the middle tube are made of a semipermeable material (Teflon AF-2400), which allows gas (CO2) to permeate through it, but retains liquid (water). In this strategy, the CO2 permeates through the inner tube (the end is sealed) then dissolves into the dirty water/particle suspension passing through the middle tube. It then diffuses radially to the outer tube, where a vacuum collects the CO2, forming a concentration gradient of ions through the water, which induces the migration of charged particles to concentrate at the inner wall of the middle tube. The vacuum phase in the outer tube can increase the concentration gradient of ions in the water and recycle the CO2. Finally, purified water can be collected from the center of the middle tube by a needle in the effluent. The purification system is able to take initial turbid water (243 NTU) to below the WHO drinking water standard (