Intersymbol and Intercarrier Interference in OFDM Transmissions through Highly Dispersive Channels

This work quantifies, for the first time, intersymbol and intercarrier interferences induced by very dispersive channels in OFDM systems. The resulting achievable data rate for \wam{suboptimal} OFDM transmissions is derived based on the computation of signal-to-interference-plus-noise ratio for arbitrary length finite duration channel impulse responses. Simulation results point to significant differences between data rates obtained via conventional formulations, for which interferences are supposed to be limited to two or three blocks, versus the data rates considering the actual channel dispersion

Early changes in rat diaphragm biology with mechanical ventilation

To better characterize the effects of 24-hour mechanical ventilation on diaphragm, the expression of myogenic transcription factors, myosin heavy chains, and sarcoplasmic/endoplasmic reticulum calcium-ATPase pumps was examined in rats. In the diaphragm of mechanically ventilated animals, the mRNA of MyoD, myosin heavy chain-2a and -2b, and sarcoplasmic/endoplasmic reticulum calcium-ATPase-1a decreased, whereas myogenin mRNA increased. In the diaphragm of anesthetized and spontaneously breathing rats, only the mRNA of MyoD and myosin heavy chain-2a decreased. MyoD and myogenin protein expression followed the changes at the mRNA, whereas the myosin heavy chain isoforms did not change. Parallel experiments involving the gastrocnemius were performed to assess the relative contribution of muscle shortening versus immobilization-induced deconditioning on muscle regulatory factor expression. Passive shortening produced no additional effects compared with immobilization-induced deconditioning. The overall changes followed a remarkably similar pattern except for MyoD protein expression, which increased in the gastrocnemius and decreased in the diaphragm while its mRNA diminished in both muscles. The early alterations in the expression of muscle protein and regulatory factors may serve as underlying molecular basis for the impaired diaphragm function seen after 24 hours of mechanical ventilation. Whether immobilization-induced deconditioning and/or passive shortening play a role in these alterations could not be fully unraveled

Drones for Desert Locust

The main goal of this project is to develop a new methodology against one of the most dangerous pests on the world, the Desert Locust. Being present in almost the 20% of the earth surface, the desert Locust can destroy all the agriculture resources and can move up to 150 km per day crossing large water areas as the Atlantic Ocean. This movement capacity makes faster the spread of this insect plague. The proposed methodology is based on the use of UAV technology. This technology has proven to have many applications and, nowadays, is only limited by the slow adaptation of the law. To better reach the goal planned, we've stablished contact with the FAO (Food and Agriculture Organization of the United Nations). Studying their methodology to fight against desert In this project, the HEMAV knowhow was basic. The daily collaboration with the UAV experts has made possible the right development of the technical and operational sides. The company collaboration was also essential to validate the technical aspects. After the technical and operational validation and the results analysis, is possible to say that the proposed methodology improves significantly the state of art of the solution. With the proper implementation of the defined tools and the right people training, it could be a revolutionary improvement capable to control this serious problem

Pressure support ventilation attenuates ventilator-induced protein modifications in the diaphragm

Common medical conditions that require mechanical ventilation include chronic obstructive lung disease, acute lung injury, sepsis, heart failure, drug overdose, neuromuscular disorders, and surgery. Although mechanical ventilation can be a life saving measure, prolonged mechanical ventilation can also present clinical problems. Indeed, numerous well-controlled animal studies have demonstrated that prolonged mechanical ventilation results in diaphragmatic weakness due to both atrophy and contractile dysfunction. Importantly, a recent clinical investigation has confirmed that prolonged mechanical ventilation results in atrophy of the human diaphragm. This mechanical ventilation-induced diaphragmatic weakness is important because the most frequent cause of weaning difficulty is respiratory muscle failure due to inspiratory muscle weakness and/or a decline in inspiratory muscle endurance. Therefore, developing methods to protect against mechanical ventilation-induced diaphragmatic weakness is important

Higher Education and Reentry: The Gifts They Bring

This study explores the lived experiences of people with criminal justice histories as they attend and contemplate enrolling in college. The report highlights the journeys of these students and considers a number of important questions: What does it take for people with criminal justice histories to successfully transform the trajectory of their lives? What are the obstacles they face? What affirmative steps can we take to make our public and private colleges and universities more welcoming to this growing population of students

Increased duration of mechanical ventilation is associated with decreased diaphragmatic force: a prospective observational study

ABSTRACT: INTRODUCTION: Respiratory muscle weakness is an important risk factor for delayed weaning. Animal data show that mechanical ventilation itself can cause atrophy and weakness of the diaphragm, called ventilator-induced diaphragmatic dysfunction (VIDD). Transdiaphragmatic pressure after magnetic stimulation (TwPdi BAMPS) allows evaluation of diaphragm strength. We aimed to evaluate the repeatability of TwPdi BAMPS in critically ill, mechanically ventilated patients and to describe the relation between TwPdi and the duration of mechanical ventilation. METHODS: This was a prospective observational study in critically ill and mechanically ventilated patients, admitted to the medical intensive care unit of a university hospital. Nineteen measurements were made in a total of 10 patients at various intervals after starting mechanical ventilation. In seven patients, measurements were made on two or more occasions, with a minimum interval of 24 hours. RESULTS: The TwPdi was 11.5 +/- 3.9 cm H2O (mean +/- SD), indicating severe respiratory muscle weakness. The between-occasion coefficient of variation of TwPdi was 9.7%, comparable with data from healthy volunteers. Increasing duration of mechanical ventilation was associated with a logarithmic decline in TwPdi (R = 0.69; P = 0.038). This association was also found for cumulative time on pressure control (R = 0.71; P = 0.03) and pressure-support ventilation (P = 0.05; R = 0.66) separately, as well as for cumulative dose of propofol (R = 0.66; P = 0.05) and piritramide (R = 0.79; P = 0.01). CONCLUSIONS: Duration of mechanical ventilation is associated with a logarithmic decline in diaphragmatic force, which is compatible with the concept of VIDD. The observed decline may also be due to other potentially contributing factors such as sedatives/analgesics, sepsis, or others.status: publishe

Symbol-asynchronous transmission in multibeam satellite user down-link : rate regions for novel superposition coding schemes

We consider the forward link of a multibeam satellite system with high spectral reuse and the novel low-complexity transmission and detection strategies from [1]. More specifically, we study the impact of a time offset between the antenna beams that cooperate to simultaneously serve a given user. Assuming Gaussian signaling, we provide closed-form expressions for the achievable rate region. It is demonstrated that, in the absence of timing information at the gateway, this region is not affected by a time offset. Our numerical results further show that, in case timing is known at the gateway, an offset of half a symbol period at both user terminals is optimal in terms of spectral efficiency.Grant numbers : Satellite Network of Experts IV. © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

Non-coherent rate-splitting for multibeam satellite forward link : practical coding and decoding algorithms

Non-Coherent Rate-Splitting (NCRS) was recently proposed as a practical multiuser coding and decoding scheme to increase the spectral efficiency of multibeam satellite communication systems. In this paper, we further study the practical realization of NCRS. We propose a modified coding scheme (NCRS*) that is robust to a nonzero time offset among beams. In NCRS*, as opposed to NCRS, the beams send independently channel encoded and modulated waveforms. We assess the performance of NCRS* in terms of the achievable rate region. It is shown that NCRS* performs worse than NCRS, but better than or comparable to other competing schemes, which, as opposed to NCRS*, require flexible bandwidth allocation or perfect synchronization at the transmitter. We also propose a new N-MAP algorithm for the practical implementation of NCRS* receivers. Similar to the existing UMAP algorithm, N-MAP takes into account the modulation used by, and the time offset between, the signals received from the different beams. In most cases, however, N-MAP has a significantly lower complexity than U-MAP

The development of a measure of enculturation for Native American youth

Enculturation is the process by which individuals learn about and identify with their ethnic minority culture. It is distinguished from acculturation which refers to the process by which an ethnic minority individual is assimilated into the majority culture. Three studies with Native American youths are reported that describe the development of a measure of enculturation for Native American youths. Development of a measure of enculturation provides a foundation upon which to build a body of literature that focuses on strengths in a youth's life rather than on deficits. Results of the first study (n=120), a confirmatory factor analysis, indicated that cultural affinity, Native American identity, and family involvement in traditional activities adequately represent the construct of enculturation. The study also provides some convergent validity for this interpretation. The second study examines factor invariance for enculturation among youths with data from over 2 years (n=69). The factor structure was similar across time. The third study replicates the factor structure and validity analyses with a new sample (n=42). Usefulness of the measure for assessing protective factors and stressing ethnicity over simple assessment of race categories is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117215/1/ajcpbf02510403.pd