A generating function perspective on the transmission forest

In a previous paper, we showed that a compartmental stochastic process model of SARS-CoV-2 transmission could be fit to time series data and then reinterpreted as a collection of interacting branching processes drawn from a dynamic degree distribution. We called this reinterpretation a transmission forest. This paper builds on that idea. Specifically, leveraging generating function methods from analytic combinatorics, we develop a theory describing the transmission forest's properties, allowing us to show for example that transmission tree interactions fade with increasing disease prevalence. We then validate the theory by computing forest statistics, like the tree survival function, which we compare to estimates based on the sampling method developed previously. The accuracy and flexibility of the analytic approach is clear, and it allows us to comment on multi-scale features of more general transmission processes

Fertility preservation in non-seminomatous germ cell tumor: a case report

Testicular germ cell tumors (TGCTs) are the most common malignancy in young men in their peak fertility years. It can intrinsically and permanently affect fertility potential of an individual. Clinicians are advised to offer Fertility Preservation before initiating the treatment. We present one such case of presence of Neoplasm in testis, where semen was cryopreserved before operating it for fertility preservation and biological pregnancy was achieved. On further investigations, presence of neoplasm on left testis was diagnosed. However, neoplasms of the testes are unique in that way they affect men at a young age and also have a high survival rates. Cryopreservation of ejaculated or surgically retrieved sperm is currently the only established method of fertility preservation for post-pubertal man. The incidence as well as rates for testicular cancers have remained relatively low and if presented early on, can be cured and has good survival rates. Fertility awareness must be raised amongst the oncologist, gynecologist and patients

Impact of COVID-19-related disruptions to measles, meningococcal A, and yellow fever vaccination in 10 countries.

BACKGROUND: Childhood immunisation services have been disrupted by the COVID-19 pandemic. WHO recommends considering outbreak risk using epidemiological criteria when deciding whether to conduct preventive vaccination campaigns during the pandemic. METHODS: We used two to three models per infection to estimate the health impact of 50% reduced routine vaccination coverage in 2020 and delay of campaign vaccination from 2020 to 2021 for measles vaccination in Bangladesh, Chad, Ethiopia, Kenya, Nigeria, and South Sudan, for meningococcal A vaccination in Burkina Faso, Chad, Niger, and Nigeria, and for yellow fever vaccination in the Democratic Republic of Congo, Ghana, and Nigeria. Our counterfactual comparative scenario was sustaining immunisation services at coverage projections made prior to COVID-19 (i.e. without any disruption). RESULTS: Reduced routine vaccination coverage in 2020 without catch-up vaccination may lead to an increase in measles and yellow fever disease burden in the modelled countries. Delaying planned campaigns in Ethiopia and Nigeria by a year may significantly increase the risk of measles outbreaks (both countries did complete their supplementary immunisation activities (SIAs) planned for 2020). For yellow fever vaccination, delay in campaigns leads to a potential disease burden rise of >1 death per 100,000 people per year until the campaigns are implemented. For meningococcal A vaccination, short-term disruptions in 2020 are unlikely to have a significant impact due to the persistence of direct and indirect benefits from past introductory campaigns of the 1- to 29-year-old population, bolstered by inclusion of the vaccine into the routine immunisation schedule accompanied by further catch-up campaigns. CONCLUSIONS: The impact of COVID-19-related disruption to vaccination programs varies between infections and countries. Planning and implementation of campaigns should consider country and infection-specific epidemiological factors and local immunity gaps worsened by the COVID-19 pandemic when prioritising vaccines and strategies for catch-up vaccination. FUNDING: Bill and Melinda Gates Foundation and Gavi, the Vaccine Alliance

Impact of COVID-19-related disruptions to measles, meningococcal A, and yellow fever vaccination in 10 countries

Background:: Childhood immunisation services have been disrupted by the COVID-19 pandemic. WHO recommends considering outbreak risk using epidemiological criteria when deciding whether to conduct preventive vaccination campaigns during the pandemic. Methods:: We used two to three models per infection to estimate the health impact of 50% reduced routine vaccination coverage in 2020 and delay of campaign vaccination from 2020 to 2021 for measles vaccination in Bangladesh, Chad, Ethiopia, Kenya, Nigeria, and South Sudan, for meningococcal A vaccination in Burkina Faso, Chad, Niger, and Nigeria, and for yellow fever vaccination in the Democratic Republic of Congo, Ghana, and Nigeria. Our counterfactual comparative scenario was sustaining immunisation services at coverage projections made prior to COVID-19 (i.e. without any disruption). Results:: Reduced routine vaccination coverage in 2020 without catch-up vaccination may lead to an increase in measles and yellow fever disease burden in the modelled countries. Delaying planned campaigns in Ethiopia and Nigeria by a year may significantly increase the risk of measles outbreaks (both countries did complete their supplementary immunisation activities (SIAs) planned for 2020). For yellow fever vaccination, delay in campaigns leads to a potential disease burden rise of >1 death per 100,000 people per year until the campaigns are implemented. For meningococcal A vaccination, short-term disruptions in 2020 are unlikely to have a significant impact due to the persistence of direct and indirect benefits from past introductory campaigns of the 1- to 29-year-old population, bolstered by inclusion of the vaccine into the routine immunisation schedule accompanied by further catch-up campaigns. Conclusions:: The impact of COVID-19-related disruption to vaccination programs varies between infections and countries. Planning and implementation of campaigns should consider country and infection-specific epidemiological factors and local immunity gaps worsened by the COVID-19 pandemic when prioritising vaccines and strategies for catch-up vaccination. Funding:: Bill and Melinda Gates Foundation and Gavi, the Vaccine Alliance

Energy and Charge Transfer in Open Plasmonic Systems

Thesis (Ph.D.)--University of Washington, 2017-03Coherent and collective charge oscillations in metal nanoparticles (MNPs), known as localized surface plasmons, offer unprecedented control and enhancement of optical processes on the nanoscale. Since their discovery in the 1950's, plasmons have played an important role in understanding fundamental properties of solid state matter and have been used for a variety of applications, from single molecule spectroscopy to directed radiation therapy for cancer treatment. More recently, experiments have demonstrated quantum interference between optically excited plasmonic materials, opening the door for plasmonic applications in quantum information and making the study of the basic quantum mechanical properties of plasmonic structures an important research topic. This text describes a quantitatively accurate, versatile model of MNP optics that incorporates MNP geometry, local environment, and effects due to the quantum properties of conduction electrons and radiation. We build the theory from first principles, starting with a silver sphere in isolation and working our way up to complex, interacting plasmonic systems with multiple MNPs and other optical resonators. We use mathematical methods from statistical physics and quantum optics in collaboration with experimentalists to reconcile long-standing discrepancies amongst experiments probing plasmons in the quantum size regime, to develop and model a novel single-particle absorption spectroscopy, to predict radiative interference effects in entangled plasmonic aggregates, and to demonstrate the existence of plasmons in photo-doped semiconductor nanocrystals. These examples show more broadly that the theory presented is easily integrated with numerical simulations of electromagnetic scattering and that plasmonics is an interesting test-bed for approximate methods associated with multiscale systems

Promising Future of PRP Treatment for Ovarian Rejuvenation: An In-House Experience of an IVF Institute

Objectives: Over the past few years platelet-rich plasma (PRP) has been shown to have beneficial effects on various organs and sites in the human body. Its effect on restoration of tissue engineering has gained tremendous popularity. Its effect in the field of reproductive medicine only got implemented in last decade. Methods: In this retrospective observational study, we observed 84 cases of ovarian rejuvenation at a fertility clinic from the year 2016 to 2019, out of which 45 were done for the indication of primary ovarian insufficiency for females that fall in the category 3 and 4 of Poseidon criterion. We did an autologous PRP ovarian treatment for each participant. The primary outcome was achieving a biological pregnancy after the procedure. Results: Out of 45 patients in the present study, 27 had achieved biological pregnancy, of which Eight were natural pregnancies, and the remaining 19 had received IVF or IUI as a fertility treatment. Out of these 27 biological pregnancies, 20 patients had a live birth, one had an ectopic pregnancy, and six had miscarriages. Conclusions: The process of autologous intraovarian treatment with PRP definitely helped patients with diminished ovarian reserve to conceive their own genetic offsprings, whose otherwise best option would have been to go through a donor egg program. Hence, PRP definitely deserves a place in the field of reproductive medicine to combat the condition of premature ovarian failure

Charge-Tunable Quantum Plasmons in Colloidal Semiconductor Nanocrystals

Nanomaterials exhibiting plasmonic optical responses are impacting sensing, information processing, catalysis, solar, and photonics technologies. Recent advances have expanded the portfolio of plasmonic nanostructures into doped semiconductor nanocrystals, which allow dynamic manipulation of carrier densities. Once interpreted as intraband single-electron transitions, the infrared absorption of doped semiconductor nanocrystals is now commonly attributed to localized surface plasmon resonances and analyzed using the classical Drude model to determine carrier densities. Here, we show that the experimental plasmon resonance energies of photodoped ZnO nanocrystals with controlled sizes and carrier densities diverge from classical Drude model predictions at small sizes, revealing quantum plasmons in these nanocrystals. A Lorentz oscillator model more adequately describes the data and illustrates a closer link between plasmon resonances and single-electron transitions in semiconductors than in metals, highlighting a fundamental contrast between these two classes of plasmonic materials