Low student enrollment and high attrition rates in Science, Technology, Engineering, and Mathematics (STEM) education are major challenges in higher education. Many STEM entrants end-up switching their majors to non-STEM fields, perform poorly relative to their peers in other programs, and/or drop out of college without earning any academic qualification. Therefore, it is important to examine strategies for reducing attrition in STEM programs. This paper reviews the major factors impeding student interest, success, and persistence in STEM programs, and current institutional practices aimed at addressing these issues. Suggested institutional strategies to improve persistence in STEM programs and their implications that are discussed in this paper include: provision of orientation programs, adoption of early warning systems, Mathematics review sessions, creation of student learning communities, professional development of faculty, as well as collaborative and outreach programs. It is hoped that this review will encourage debate toward solving the major challenges facing STEM education.

Older adults aged 65 and over will make up more than 20% of U.S. residents by 2030, and in 2050, this population will reach 83.7 million. Depression among older adults is a major public health concern projected to be the second leading cause of disease burden. Despite having Medicare, and other employer supplements, the burden of out of pocket healthcare expenses may be an important predictor of depression. The current study aims to investigate whether delay in seeing a doctor when needed but could not because of medical cost is significantly associated with symptoms of current depression in older adults. Cross-sectional data from the 2011 Behavioral Risk Factor Surveillance System (BFRSS) from 12 states and Puerto Rico were used for this study (n = 24,018). The prevalence of symptoms of current depression among older adults who reported medical cost as a barrier to seeking health care was significantly higher (17.8%) when compared to older adults who reported medical cost not being a barrier to seeking health care (5.5%). Older adults who reported medical cost as a barrier to seeking health care were more likely to report current depressive symptoms compared to their counterparts [Adjusted Odds Ratio (AOR): 2.2 [95% CI: 1.5–3.3]). Older adults (≥ 65 years of age) who experience the burden of medical cost for health care are significantly more likely to report symptoms of depression. Health care professionals and policymakers should consider effective interventions to improve access to health care among older adults.

Worldwide, breast cancer has become the second most common cancer in women. The disease has currently been named the most deadly cancer in women but little is known on what causes the disease. We present the effects of estrogen as a risk factor on the dynamics of breast cancer. We develop a deterministic mathematical model showing general dynamics of breast cancer with immune response. This is a four-population model that includes tumor cells, host cells, immune cells, and estrogen. The effects of estrogen are then incorporated in the model. The results show that the presence of extra estrogen increases the risk of developing breast cancer.

Schistosomiasis infection is characterized by the presence of adult worms in the portal and mesenteric veins of humans as part of a complex migratory cycle initiated by cutaneous penetration of the cercariae shed by infected freshwater snails. The drug praziquantel is not always effective in the treatment against schistosomiasis at larvae stage. However, our simulations show that it is effective against mature worms and eggs. As a result, the study and understanding of immunological responses is key in understanding parasite dynamics. We therefore introduce quantitative interpretations of human immunological responses of the disease to formulate mathematical models for the within‐host dynamics of schistosomiasis. We also use numerical simulations to demonstrate that it is the level of T cells that differentiates between either an effective immune response or some degree of infection. These cells are responsible for the differentiation and recruitment of eosinophils that are instrumental in clearing the parasite. From the model analysis, we conclude that control of infection is much attributed to the value of a function f, a measure of the average number of larvae penetrating a susceptible individual having hatched from an egg released by an infected individual. This agrees with evidence that there is a close association between the ecology, the distribution of infection and the disease.