Wireless PCS systems modeling and optimization using DEDS approaches

Discrete event dynamical systems (DEDS) are a class of man-made systems, which are driven by a set of discrete events. Typical examples include queuing systems, manufacturing systems, telecommunication networks, and so on. In the past two decades, the modeling, simulation, and optimization of DEDS have received considerable attention. The objective of this thesis is to apply the DEDS approaches to study wireless personal communication systems. Two applications are studied: the call request buffering problem and the mobile terminal location tracking problem. In a personal communication service network, a set of channels is assigned to every cell. When a phone call arrives and is assigned a channel, it consumes the channel until the end of the conversation. If no channel is available, the call is dropped/blocked. In many cases, some channels may become available shortly after a call is dropped. Thus, if some buffering mechanism is used, a cell may accommodate more phone calls and thus the channel utilization is increased. This is referred to as call request buffering. The first part of this thesis develops an algorithm to estimate the sensitivity of a Markov process using a single sample path of its uniformization Markov chain, and uses a gradient algorithm to find a locally optimal parameter. After that, a random call request buffering scheme is introduced, which is optimized using the proposed algorithm. In a wireless personal communication service system, in order to deliver a phone call, the network has to track the mobile terminals' locations from time to time. The second part of the thesis proposes a mobile terminal location update model, whose states consist of two components--the time elapsed since last call arrived and the distance the mobile terminal has traveled since last registration

When do tripdoublet states fluoresce? A theoretical study of copper(II) porphyrin

Open-shell molecules rarely fluoresce, due to their typically faster non-radiative relaxation rates compared to closed-shell ones. Even rarer is the fluorescence from states that have two more unpaired electrons than the open-shell ground state, since they involve excitations from closed-shell orbitals to vacant-shell orbitals, which are typically higher in energy compared to excitations from or out of open-shell orbitals. States that are dominated by the former type of excitations are known as tripdoublet states when they can be described as a triplet excitation antiferromagnetically coupled to a doublet state, and their description by unrestricted single-reference methods (e.g., U-TDDFT) is notoriously inaccurate due to large spin contamination. In this work, we applied our spin-adapted TDDFT method, X-TDDFT, and the efficient and accurate static-dynamic-static second order perturbation theory (SDSPT2), to the study of the excited states as well as their relaxation pathways of copper(II) porphyrin; previous experimental works suggested that the photoluminescence of some substituted copper(II) porphyrins originate from a tripdoublet state, formed by a triplet ligand π → π* excitation antiferromagnetically coupled with the unpaired d electron. Our results demonstrated favorable agreement between the X-TDDFT, SDSPT2 and experimental excitation energies, and revealed noticeable improvements of X-TDDFT compared to U-TDDFT, not only for vertical excitation energies but also for adiabatic energy differences. These suggest that X-TDDFT is a reliable tool for the study of tripdoublet state fluorescence. Intriguingly, we showed that the aforementioned tripdoublet state is only slightly above the lowest doublet excited state and lies only slightly higher than the lowest quartet state, which suggests that the tripdoublet of copper(II) porphyrin is long-lived enough to fluoresce due to a lack of efficient non-radiative relaxation pathways; an explanation for this unusual state ordering is given. Indeed, thermal vibration correlation function (TVCF)-based calculations of internal conversion, intersystem crossing, and radiative transition rates confirm that copper(II) porphyrin emits thermally activated delayed fluorescence (TADF) and a small amount of phosphorescence at low temperature (83 K), in accordance with experiment. The present contribution is concluded by a few possible approaches of designing new molecules that fluoresce from tripdoublet states

Case report and literature review: Robot-assisted laparoscopic left renal mucinous cystadenocarcinoma radical nephrectomy

BackgroundMucinous cystadenocarcinoma (MC) of the kidney is a rare renal epithelial tumor originating from the renal pelvic urothelium. There are only a few published reports on MC. Due to its rare and unknown tissue origin, its diagnosis is difficult which almost can be diagnosed through the pathological method.Case presentationIn this case report, we report a female patient whose chief complaint was low back pain lasting for one month. The three-dimensional computed tomography scan of the urinary system detected approximately 7 cm of a left renal cystic mass. The renal cystic mass was diagnosed as MC after robot-assisted laparoscopic radical nephrectomy. The MC originated from the kidney after completing colorectal adenocarcinoma and ovarian adenocarcinoma.ConclusionsWe reported a case of MC of the kidney which was a rare renal tumor. We not only aimed to present an unusual case of MC and review the previous literature on its pathology and differential diagnosis, but also used new method to treat this type of tumor

Modified hood technique for single-port robot-assisted radical prostatectomy contributes to early recovery of continence

Background and purposeUrinary incontinence is one of the common side effects of robot-assisted radical prostatectomy (RARP). Here, we described the modified Hood technique for single-port RARP (sp-RARP) and assessed the interest of this new technique for early continence recovery.MethodsWe retrospectively reviewed 24 patients who underwent sp-RARP modified hood technique from June 2021 to December 2021. The pre-and intraoperative variables, postoperative functional and oncological outcomes of patients were collected and analyzed. The continence rates were estimated at 0 day, 1 week, 4 weeks, 3 months and 12 months after catheter removal. Continence was defined as wearing no pad over a 24 h period.ResultsMean time of operation and estimated blood loss were 183 min and 170 ml, respectively. The postoperative continence rates at 0 day, 1 week, 4 weeks, 3 months and 12 months after catheter removal were 41.7%, 54.2%, 75.0%, 91.7% and 95.8%, respectively. There were two patients who detected positive surgical margins and no patients observed complications requiring further treatment.ConclusionThe modified hood technique is a safe and feasible method that provides better outcomes in terms of early return of continence, without increasing estimated blood loss and compromising oncologic outcomes

Relationships between SHANK3 and Autism Spectrum Disorder

Autism Spectrum Disorder is a term that is used to describe people who have difficulties communicating with others and limited actions repetitive actions. Autism could be caused by both genetic and environmental conditions, and the Shank3 gene in the Shank family is one of the high-risk genes that has been found as one of the factors. However, although a lot of researches have been done to find out the relationships between Shank3 and autism, it is known by only a few people. This article will briefly talk about autism and Shank3 and review how Shank3 mutation causes autism and the changes in the brain and behaviour

Likelihood ratio and a class of strong laws for the sequence of integer-valued random variables

In this paper, the notion of likelihood ratio, as a measure of the deviation between a sequence of integer-valued random variables and an independent random sequence with Poisson distribution is introduced, and a class of strong laws, expressed by inequalities, on certain sets determined by this notion, are obtained. A class of strong laws for a sequence of independent Poisson random variables are special cases of the results of this paper.Strong law Strong law of large numbers Likelihood ratio Poisson distribution

Efficient image recognition using local feature and fuzzy triangular number based similarity measures

Image local scale invariant features are of great importance for object recognition. Among various local scale invariant feature descriptors, Scale Invariant Feature Transform (SIFT) descriptor has been shown to be the most descriptive one and thus widely applied to image retrieval, object recognition and computer vision. By SIFT descriptor, an image may be described by hundreds of key points with each point depicted by a 128-element feature vector; this representation makes the subsequent feature matching very computationally demanding. In this paper, we propose to incorporate the fuzzy set concepts into SIFT features and define fuzzy similarity between images. The proposed approach is applied to image recognition. Experimental results with the coil-100 image database are provided to show the superiority of the proposed approach.Peer reviewed: YesNRC publication: Ye

Cancer and the healthy immigrant effect: a statistical analysis of cancer diagnosis using a linked Census-cancer registry administrative database

Abstract Background A large volume of research has been published on both the socio economic and demographic determinants of cancer and on the health of immigrants and minority groups. Yet because of data limitations, little research examines differences in the occurrence of cancer incidence between immigrants and non-immigrants and among immigrants defined by region of birth and time in the host country. In particular it is not known whether a healthy immigrant effect is present for cancer and if so, whether this advantage is lost with additional years of residence in the host country. Methods This paper uses a large data file from Statistics Canada that links Census information on immigrant status, socioeconomic status including educational attainment, and other person-level information with administrative data on cancer and mortality over a continuous 13 year period of observation. It estimates discrete and continuous time duration models to identify differences in cancer diagnosis by immigrant subgroup after controlling for a variety of potential confounders. Differences in historical smoking behavior are not observable at the individual level in the dataset but are accounted for indirectly using various methods. Results Results in general confirm the existence of a healthy immigrant effect for cancer in that, overall, recent immigrants to Canada are significantly less likely than otherwise comparable non-immigrant Canadians to be diagnosed with any cancer and the most common forms of cancer by site. As well, this gap appears to decline with additional years in Canada for immigrant men and women, eventually converging to Canadian-born levels. Differentiating among immigrant subgroups by period of arrival and country of birth reveals significant variation across immigrant subgroups, with immigrant men and women from developing countries typically having a lower likelihood of being diagnosed with cancer than immigrants from the US, UK and continental Europe. As well, controlling for immigrant heterogeneity this way weakens the conclusion that the gap narrows with years in Canada. Immigrant men overall continue to exhibit convergence to Canadian-born levels for diagnosis of any cancer and for prostate cancer, while immigrant women exhibit narrowing over time only for breast cancer. Although smoking behavior is not directly observed, controlling for subgroup-specific lifetime smoking behavior using survey data has only a relatively minor effect on the estimated differences. Conclusions The specificity of the results by cancer type, gender, immigrant status and ethnicity provides useful guidance for future research by helping to narrow the possible channels through which social and economic characteristics may be affecting cancer incidence

Surface Phosphatidylserine Is Responsible for the Internalization on Microvesicles Derived from Hypoxia-Induced Human Bone Marrow Mesenchymal Stem Cells into Human Endothelial Cells.

Previous data have proven that microvesicles derived from hypoxia-induced mesenchymal stem cells (MSC-MVs) can be internalized into endothelial cells, enhancing their proliferation and vessel structure formation and promoting in vivo angiogenesis. However, there is a paucity of information about how the MSC-MVs are up-taken by endothelial cells.MVs were prepared from the supernatants of human bone marrow MSCs that had been exposed to a hypoxic and/or serum-deprivation condition. The incorporation of hypoxia-induced MSC-MVs into human umbilical cord endothelial cells (HUVECs) was observed by flow cytometry and confocal microscopy in the presence or absence of recombinant human Annexin-V (Anx-V) and antibodies against human CD29 and CD44. Further, small interfering RNA (siRNA) targeted at Anx-V and PSR was delivered into HUVECs, or HUVECs were treated with a monoclonal antibody against phosphatidylserine receptor (PSR) and the cellular internalization of MVs was re-assessed.The addition of exogenous Anx-V could inhibit the uptake of MVs isolated from hypoxia-induced stem cells by HUVECs in a dose- and time-dependent manner, while the anti-CD29 and CD44 antibodies had no effect on the internalization process. The suppression was neither observed in Anx-V siRNA-transfected HUVECs, however, addition of anti-PSR antibody and PSR siRNA-transfected HUVECs greatly blocked the incorporation of MVs isolated from hypoxia-induced stem cells into HUVECs.PS on the MVs isolated from hypoxia-induced stem cells is the critical molecule in the uptake by HUVECs

Azobisisobutyronitrile Initiated Aerobic Oxidative Transformation of Amines: Coupling of Primary Amines and Cyanation of Tertiary Amines

In the presence of a catalytic amount of radical initiator AIBN, primary amines are oxidatively coupled to imines and tertiary amines are cyanated to α-aminonitriles. These “metal-free” aerobic oxidative coupling reactions may find applications in a wide range of “green” oxidation chemistry