Small zeros of quadratic forms mod P²

This paper considers downlink multiantenna communication with base stations that perform cooperative precoding in a distributed fashion. Most previous work in the area has assumed that transmitters have common knowledge of both data symbols of all users and full or partial channel state information (CSI). Herein, we assume that each base station only has local CSI, either instantaneous or statistical. For the case of instantaneous CSI, a parametrization of the beamforming vectors used to achieve the outer boundary of the achievable rate region is obtained for two multi-antenna transmitters and two single-antenna receivers. Distributed generalizations of classical beamforming approaches that satisfy this parametrization are provided, and it is shown how the distributed precoding design can be improved using the so-called virtual SINR framework. Conceptually analog results for both the parametrization and the beamforming design are derived in the case of local statistical CSI. Heuristics on the distributed power allocation are provided in both cases, and the performance is illustrated numerically

Robust leakage-based distributed precoder for cooperative multicell systems

Coordinated multipoint (CoMP) from long term evolution (LTE)-advanced is a promising technique to enhance the system spectral efficiency. Among the CoMP techniques, joint transmission has high communication requirements, because of the data sharing phase through the backhaul network, and coordinated scheduling and beamforming reduces the backhaul requirements, since no data sharing is necessary. Most of the available CoMP techniques consider perfect channel knowledge at the transmitters. Nevertheless for practical systems this is unrealistic. Therefore in this study the authors address this limitation by proposing a robust precoder for a multicell-based systems, where each base station (BS) has only access to an imperfect local channel estimate. They consider both the case with and without data sharing. The proposed precoder is designed in a distributed manner at each BS by maximising the signal-to-leakage-and-noise ratio of all jointly processed users. By considering the channel estimation error in the design of the precoder, they are able to reduce considerably the impact of these errors in the system's performance. The results show that the proposed scheme has improved performance especially for the high signal-to-noise ratio regime, where the impact of the channel estimation error may be more pronounced

Molecular and all solid DFT studies of the magnetic and chemical bonding properties within KM[Cr(CN)6_6] (M = V, Ni) complexes

A study at both the molecular and extended solid level in the framework DFT is carried out for KM[Cr(CN)$_6$] (M = V, Ni). From molecular calculations, the exchange parameters J are obtained, pointing to the expected magnetic ground states, i.e., antiferromagnetic for M = V with J = -296.5 cm$^{-1}$ and ferromagnetic for M = Ni with J = +40.5 cm$^{-1}$. From solid state computations the same ground states and J magnitudes are confirmed from energy differences. Furthermore an analysis of the site projected density of states and of the chemical bonding is developed in which the cyanide ion linkage is analyzed addressing some isomerism aspects.Comment: new results, 5 tables, 7 fig

Plummer-Vinson Syndrome

A 37-year-old African American woman with no past medical history presented to the Emergency Department with a chief complaint of abdominal pain. She also reported associated fatigue and dysphagia. Over the past two months, she reported 40 Lbs. unintentional weight loss and decrease appetite. Her dysphagia primarily to solids, which also had been worsening over the past few weeks. She had no history of similar symptoms in the past. She was not on any medications. On admission, vital signs were stable. In the Emergency Department,. Hemoglobin on admission was 3.3 g/dL [11.9–15.1 g/dL] with a mean corpuscular volume of 61.1. Her serum iron on admission was 10 ug/dL [60–140 ug/dL], iron saturation was 2% [15–50%], and ferritin was 1.0 ng/mL [11.0–307 ng/mL]. Upon further questioning, the patient stated that she did not describe menorrhagia. She denied hematemesis, hematochezia, or melena. She was transfused with 3 units of packed red blood cells and was started on 1000 mg of IV iron dextran complex infusions. Gastroenterology was consulted, and the patient underwent esophagogastroduodenoscopy (EGD) and colonoscopy. Colonoscopy showed erythematous and edematous mucosa in the terminal ileum which was Biopsied. The EGD revealed a few intrinsic stenoses in the upper esophagus which were successfully dilated with savary. A pathology exam of the terminal ileum showed well differentiated neuroendocrine tumor. Given the clinical, laboratory, and endoscopic (as shown below) Esophageal web located in the upper esophagus. a diagnosis of Plummer-Vinson syndrome was made. Her dysphagia improved over the three days in the hospital after iron infusions and blood transfusions, and she was able to tolerate a regular diet. Approximately 2 months after her discharge, a follow-up phone call was made to the patient. She stated that she had been compliant with all her medications and her dysphagia had resolved. At the time of the phone call, she was tolerating a regular diet without any dietary restrictions.https://scholarlycommons.henryford.com/merf2020caserpt/1132/thumbnail.jp

Bodies on the Border: Between Ableist Cures, Nationalist Hostilities & Deadly Futures

This series of images emerges from a collaboration between academics and artists focused on organ transplantation and chronic illness. The images are part of the ongoing work of Capturing Chronic Illness, a project founded by UK-based medical humanities academics Donna McCormack (University of Strathclyde, UK) and Ingrid Young (University of Edinburgh, UK) to explore how arts may engage with health, illness, and non-normative embodiments that exceed dominant narratives. The exchange that produced the images is based directly on McCormack’s project, Transplant Imaginaries, which analyses fictional texts (novels and films) to explore biotechnological and anticolonial embodiments and relationalities in representations of transplantation. The three images, produced with Lynne Zakhour and Richard Kahwagi, explore transplant medicine beyond a curative imaginary. They point to key issues that are rarely discussed or even acknowledged in the clinic, but may be discussed in memoirs, by recipients and in fiction. These images, then, push us to reconsider how organ transplantation necessarily demands we pay attention to those embodied stories of living with the dead, crossing borders and how care, even that deemed "lifesaving," may be violent.Capturing Chronic Illness explores how the arts can listen to silenced or denied experiences of (particularly) queer health and illne