Staged HIV transmission and treatment in a dynamic model with long-term partnerships.

The transmission dynamics of HIV are closely tied to the duration and overlap of sexual partnerships. We develop an autonomous population model that can account for the possibilities of an infection from either a casual sexual partner or a long-term partner who was either infected at the start of the partnership or has been newly infected since the onset of the partnership. The impact of the long-term partnerships on the rate of infection is captured by calculating the expected values of the rate of infection from these extended contacts.

The effect of PrEP uptake and adherence on the spread of HIV in the presence of casual and long-term partnerships.

A model with both casual and long-term partnerships is considered with respect to the impact of a pre-exposure prophylaxis (PrEP) on the spread of HIV. We consider the effect of the effectiveness of PrEP, the rate that susceptible individuals choose to take PrEP, and compliance with the daily dose of the pre-exposure prophylaxis. The rate of infection in long-term partnerships is computed using a linearized expected value as a means for including the nonlocal effects of long-term partnerships while maintaining computational feasibility.

Minimizing disease spread on a quarantined cruise ship: A model of COVID-19 with asymptomatic infections.

On February 5 the Japanese government ordered the passengers and crew on the Diamond Princess to start a two week quarantine after a former passenger tested positive for COVID-19. During the quarantine the virus spread rapidly throughout the ship. By February 20, there were 651 cases.

Technologies for supporting high-order geodesic mesh frameworks for computational astrophysics and space sciences.

Many important problems in astrophysics, space physics, and geophysics involve flows of (possibly ionized) gases in the vicinity of a spherical object, such as a star or planet. The geometry of such a system naturally favors numerical schemes based on a spherical mesh. Despite its orthogonality property, the polar (latitude-longitude) mesh is ill suited for computation because of the singularity on the polar axis, leading to a highly non-uniform distribution of zone sizes.

A sexually transmitted infection model with long-term partnerships in homogeneous and heterogenous populations.

Population models for sexually transmitted infections frequently use a transmission model that assumes an inherent partnership length of zero. However, in a population with long-term partnerships, the infection status of the partners, the length of the partnership, and the exclusivity of the partnership significantly affect the rate of infection. We develop an autonomous population model that can account for the possibilities of an infection from either a casual sexual partner or a longtime partner who was either infected at the start of the partnership or was newly infected.

Intermittent Preventive Treatment (IPT): Its Role in Averting Disease-Induced Mortality in Children and in Promoting the Spread of Antimalarial Drug Resistance.

We develop an age-structured ODE model to investigate the role of intermittent preventive treatment (IPT) in averting malaria-induced mortality in children, and its related cost in promoting the spread of antimalarial drug resistance. IPT, a malaria control strategy in which a full curative dose of an antimalarial medication is administered to vulnerable asymptomatic individuals at specified intervals, has been shown to reduce malaria transmission and deaths in children and pregnant women. However, it can also promote drug resistance spread.

Influence of concurrency, partner choice, and viral suppression on racial disparity in the prevalence of HIV infected women.

In 1992, Watts and May introduced a simple dynamical systems model of the spread of HIV based on disease transmission per partnership including the length of partnership duration. This model allowed for the treatment of concurrent partnerships, although it was hampered by the assumption of an important latent phase which generated a non-autonomous system. Subsequent models including concurrency have been based on networks, Monte Carlo, and stochastic simulations which lose a qualitative understanding of the effects of concurrency.

Analysis of SI models with multiple interacting populations using subpopulations.

Computing endemic equilibria and basic reproductive numbers for systems of differential equations describing epidemiological systems with multiple connections between subpopulations is often algebraically intractable. We present an alternative method which deconstructs the larger system into smaller subsystems and captures the interactions between the smaller systems as external forces using an approximate model. We bound the basic reproductive numbers of the full system in terms of the basic reproductive numbers of the smaller systems and use the alternate model to provide approximations for the endemic equilibrium.

Convective Instabilities in Two Liquid Layers.

We perform linear stability calculations for horizontal fluid bilayers, taking into account both buoyancy effects and thermocapillary effects in the presence of a vertical temperature gradient. To help understand the mechanisms driving the instability, we have performed both long-wavelength and short-wavelength analyses. The mechanism for the large wavelength instability is complicated, and the detailed form of the expansion is found to depend on the Crispation and Bond numbers.

Host age, but not host location within a stream, is correlated with the prevalence of gut parasites in water striders.

We tested for correlations between the geographic, demographic, and temporal distribution of an aquatic insect host and the prevalence of its gut parasites in southwestern Ohio. Trypanosomatids were present in Aquarius remigis collected from all 4 streams surveyed in the watershed. Prevalence declined dramatically from May to July and remained low through the fall.

Decay rates of internal waves in a fluid near the liquid-vapor critical point.

We study the damping of internal waves in a viscous fluid near the liquid-vapor critical point. Such a fluid becomes strongly stratified by gravity due to its large compressibility. Using the variable-density incompressible Navier-Stokes equations, we model an infinite fluid layer with rigid horizontal boundaries and periodic side boundary conditions.

Human papillomavirus vaccines for cervical cancer.

Cervical cancer is one of the most common causes of cancer-related death in women. As a result of several recent advances in molecular biology, the association between human papillomavirus (HPV) infection and cervical cancer has been firmly established, and the oncogenic potential of certain HPV types has been clearly demonstrated. Several lines of evidence suggest the importance of the host's immune response, especially cellular immune response, in the pathogenesis of HPV-associated cervical lesions.

Induction of specific CD8+ T-lymphocyte responses using a human papillomavirus-16 E6/E7 fusion protein and autologous dendritic cells.

When intracellular viral proteins are degraded, only a limited number of peptide epitopes are capable of eliciting specific CD8+ cellular immune responses for a given human leukocyte antigen (HLA) haplotype. We sought to induce CD8+ T-lymphocyte (CTL) responses to human papillomavirus-16 (HPV-16) E6 and E7 proteins using a recombinant E6/E7 fusion protein and autologous human dendritic cells (DCs). CTLs were generated by in vitro stimulation using a recombinant HPV-16 E6/E7 fusion protein and autologous DCs from a healthy HLA-A*0201 donor.

Cell-mediated immunological responses in cervical and vaginal cancer patients immunized with a lipidated epitope of human papillomavirus type 16 E7.

Human papillomavirus (HPV) infection has been causally associated with cervical cancer. We tested the effectiveness of an HLA-A*0201-restricted, HPV-16 E7 lipopeptide vaccine in eliciting cellular immune responses in vivo in women with refractory cervical cancer. In a nonrandomized Phase I clinical trial, 12 women expressing the HLA-A2 allele with refractory cervical or vaginal cancer were vaccinated with four E786-93 lipopeptide inoculations at 3-week intervals.

Progress and prospects in vaccine therapy for gynecologic cancers.

Therapeutic and prophylactic vaccines that harness the potential of the immune system against a number of gynecologic cancers are now being developed. The therapeutic vaccines coerce the cellular components of the immune system to attack malignant tissue. The prophylactic vaccines induce the production of antibodies capable of neutralizing viral antigens before they infect host cells.

Adrenal function following high-dose steroids in ovarian cancer patients.

Purpose: Steroid doses similar to those used to prevent paclitaxel-associated hypersensitivity reactions and cisplatin-induced nausea have been associated with hypothalamic-pituitary-adrenal (HPA) axis suppression. We assessed HPA function in patients receiving high-dose steroids as part of their chemotherapy regimen for epithelial ovarian cancer.

Patients And Methods: From January to July 1994, a cross-sectional study of HPA function was performed on patients receiving dexamethasone (DEX) as part of their paclitaxel and cisplatin chemotherapy regimen (n = 9).

Detection and patterns of treatment failure in 300 consecutive cases of "early" endometrial cancer after primary surgery.

From November 1977 to July 1987, 300 consecutive patients with endometrial carcinoma clinically confined to the uterine corpus underwent primary surgery consisting of at least abdominal hysterectomy and adnexectomy. Patients with aggressive disease characteristics received postoperative radiotherapy. Forty-seven patients (16%) demonstrated recurrent disease from 2 to 125 (median of 12.