Down-converter for GPS applications

An RF down/up converter system is presented for indoor GPS applications. Transmission of GPS signals directly into indoor environments are limited and in some cases prohibited for regular operation of GPS system. However, ISM frequency bands, especially 433MHz can be used to retransmit the GPS signals to indoors. In this paper, RF down-converter building blocks are designed and implemented for sending GPS signals in ISM band. The down-converter system has heterodyne architecture which has LNAs, mixer, oscillator and filters. Received signals from the satellites are amplified, downconverted, filtered and again amplified. The overall performance of the designed system is 54.3dB gain and 2 dB noise figure while it is drawing 78mA current with 3V supply

A Comprehensive Look at Intergroup Relations and Contact Between International Students and the Host Community

Previous research has demonstrated that intergroup relations and contact between international students and host communities may be challenging. While international students sometimes experience discrimination on- or off-campus, international students themselves may also form negative attitudes toward host community members based on imagined or real experiences with them. Therefore, to address this issue, this dissertation set out to investigate variables that may lead to potentially prejudicial attitudes between international students and host community members and to examine the link between such attitudes and the quantity and quality of intergroup contact. Study 1 explored potential factors that inform francophone residents’ attitudes toward international students in English-medium universities in Montréal and examined the link between their quality and quantity of contact and their attitudes and perceived threat. First, between-group comparisons revealed similarly positive attitudes toward and relatively low levels of perceived threat from international students, except for linguistic threat, which was significantly higher for non-student francophones. Non-student francophones also reported considerably less frequent and lower quality of contact with international students. Second, while symbolic threat was the common predictor of attitudes for both student and non-student francophones, intergroup anxiety also emerged as a significant predictor of student francophones’ attitudes toward international students. Third, contact quality yielded significant associations with both attitudes (positive) and all types of perceived threat (negative except for stereotypes), whereas contact quantity was linked with intergroup anxiety only for student francophones. Study 2 essentially replicated Study 1 to provide the international student perspective regarding intergroup attitudes and contact. International students reported similarly low perceived threat from (except for linguistic threat) as well as comparably high quality of contact with student and non-student francophones. However, they indicated significantly more favourable attitudes and more frequent contact with non-student francophones. While intergroup anxiety was the predictor of attitudes toward student francophones, stereotypes predicted their attitudes toward non-student francophones. Contact quality yielded positive links with attitudes and negative associations with all perceived threats, except for stereotypes. Contact quantity, on the other hand, was associated with intergroup anxiety, linguistic threat, and stereotypes only for non-student francophones

Spatio-temporal Weather Forecasting and Attention Mechanism on Convolutional LSTMs

Numerical weather forecasting on high-resolution physical models consume hours of computations on supercomputers. Application of deep learning and machine learning methods in forecasting revealed new solutions in this area. In this paper, we forecast high-resolution numeric weather data using both input weather data and observations by providing a novel deep learning architecture. We formulate the problem as spatio-temporal prediction. Our model is composed of Convolutional Long-short Term Memory, and Convolutional Neural Network units with encoder-decoder structure. We enhance the short-long term performance and interpretability with an attention and a context matcher mechanism. We perform experiments on high-scale, real-life, benchmark numerical weather dataset, ERA5 hourly data on pressure levels, and forecast the temperature. The results show significant improvements in capturing both spatial and temporal correlations with attention matrices focusing on different parts of the input series. Our model obtains the best validation and the best test score among the baseline models, including ConvLSTM forecasting network and U-Net. We provide qualitative and quantitative results and show that our model forecasts 10 time steps with 3 hour frequency with an average of 2 degrees error. Our code and the data are publicly available

Controlled reperfusion for different durations in the treatment of ischemia-reperfusion injury of the rat ovary: evaluation of biochemical features, molecular gene expression, and histopathology

High numbers of proinflammatory cells (PMNLs), which are carried by the blood to ischemic tissue during reperfusion, are considered responsible for inducing the inflammatory response that occurs in ischemia-reperfusion (I/R) injury. Our objective was to determine the controlled reperfusion (CR) interval duration (CRID) that would minimize the injury caused by the PMNLs that infiltrate ischemic tissue. Animal groups were divided into the following groups: Sham group, ovarian I/R group (OIR), and ovarian ischemia controlled-reperfusion groups OICR-1, OICR-2, OICR-3, OICR-4, OICR-5, OICR-6, which had their ovarian artery opened and then closed for 10, 8, 6, 4, 2, or 1 s, respectively. The results show that the COX-2 activity and the gene expression decreased while the COX-1 activity and the gene expression were found to be increased in parallel to the shortening of the period in CRID. From the histopathological examinations, the findings of hemorrhage, edema, congested vascular structures, degenerated cells, and migration and adhesion of PMNLs were scaled as follows: Sham group < OICR-6 < OICR-5 < OICR-4 < OICR-3 < OICR-2 < OICR-1. The results from the histopathological assessments were consistent with the molecular and biochemical findings. In conclusion, our findings suggest that increased COX-2 activity plays a role in I/R injury of the rat ovary, and that controlled reperfusion for 3, 2, or 1 s following 2 h of ischemia may attenuate the effects of I/R injury

A Patient With AIRE Mutation Who Presented With Severe Diarrhea and Lung Abscess

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) (polyglandular endocrinopathy type 1) is a rare autosomal recessive disorder caused by mutations in the autoimmune regulator gene (AIRE). The major clinical features of APECED are hypoparathyroidism, adrenal insufficiency (Addison disease), and chronic mucocutaneous candidiasis. This disease is also associated with multiple other and uncommon autoimmune (autoimmune hepatitis, autoimmune enteropathy, atrophic gastritis with or without pernicious anemia, gonadal failure, diabetes mellitus, hypothyroidism, functional hyposplenism), ectodermal (alopecia and vitiligo), and inflammatory (intestinal lung disease, nephritis) features. Here, we report a case of a 13-year-old Turkish boy who presented wih enteropathy and lung abscess. Molecular genetic analysis demonstrated a homozygous frameshift mutation (p.Asp70fs, c.208_209insCAGG) in exon 2, in AIRE gene. APECED may present with severe, life-threatening infections due to functional hyposplenism. Multidisciplinary approach, careful follow-up, and molecular genetic studies are needed

Process development for an effective COVID-19 vaccine candidate harboring recombinant SARS-CoV-2 delta plus receptor binding domain produced by Pichia pastoris

Abstract Recombinant protein-based SARS-CoV-2 vaccines are needed to fill the vaccine equity gap. Because protein-subunit based vaccines are easier and cheaper to produce and do not require special storage/transportation conditions, they are suitable for low-/middle-income countries. Here, we report our vaccine development studies with the receptor binding domain of the SARS-CoV-2 Delta Plus strain (RBD-DP) which caused increased hospitalizations compared to other variants. First, we expressed RBD-DP in the Pichia pastoris yeast system and upscaled it to a 5-L fermenter for production. After three-step purification, we obtained RBD-DP with > 95% purity from a protein yield of > 1 g/L of supernatant. Several biophysical and biochemical characterizations were performed to confirm its identity, stability, and functionality. Then, it was formulated in different contents with Alum and CpG for mice immunization. After three doses of immunization, IgG titers from sera reached to > 106 and most importantly it showed high T-cell responses which are required for an effective vaccine to prevent severe COVID-19 disease. A live neutralization test was performed with both the Wuhan strain (B.1.1.7) and Delta strain (B.1.617.2) and it showed high neutralization antibody content for both strains. A challenge study with SARS-CoV-2 infected K18-hACE2 transgenic mice showed good immunoprotective activity with no viruses in the lungs and no lung inflammation for all immunized mice

Can we predict patients that will not benefit from invasive mechanical ventilation? A novel scoring system in intensive care: the IMV mortality prediction score (IMPRES)

KUCUK, Ahmet Oguzhan/0000-0002-6993-0519; Kirakli, Cenk/0000-0001-6013-7330; KUCUK, Mehtap PEHLIVANLAR/0000-0003-2247-4074; Aksoy, Iskender/0000-0002-4426-3342WOS: 000504051300010PubMed: 31655511Background/aim: The present study aimed to define the clinical and laboratory criteria for predicting patients that will not benefit from invasive mechanical ventilation (IMV) treatment and determine the prediction of mortality and prognosis of these critical ill patients. Materials and methods: The study was designed as an observational, multicenter, prospective, and cross-sectional clinical study. It was conducted by 75 researchers at 41 centers in intensive care units (ICUs) located in various geographical areas of Turkey. It included a total of 1463 ICU patients who were receiving invasive mechanical ventilation (IMV) treatment. A total of 158 parameters were examined via logistic regression analysis to identify independent risk factors for mortality; using these data, the IMV Mortality Prediction Score (IMPRES) scoring system was developed. Results: The following cut-off scores were used to indicate mortality risk: 8, very high risk. There was a 26.8% mortality rate among the 254 patients who had a total IMPRES score of lower than 2. The mortality rate was 93.3% for patients with total 1M PRES scores of greater than 8 (P < 0.001). Conclusion: The present study included a large number of patients from various geographical areas of the country who were admitted to various types of ICUs, had diverse diagnoses and comorbidities, were intubated with various indications in either urgent or elective settings, and were followed by physicians from various specialties. Therefore, our data are more general and can be applied to a broader population. This study devised a new scoring system for decision-making for critically ill patients as to whether they need to be intubated or not and presents a rapid and accurate prediction of mortality and prognosis prior to ICU admission using simple clinical data