A Level‐of‐Service Concept for Planning Future Water Supply Projects under Probabilistic Demand and Supply Framework

One of the most challenging tasks of water supply utilities is planning the timing and quantity of new water supply sources as demand for water consumption grows. Many water supply utilities target on meeting 100% of their customers' needs based on scenario‐based deterministic demand projections numbers even though there are uncertainties in both supply and demand values. This may result in under or overly conservative approach in assessing future needs. In this article, a level‐of‐service concept is introduced to capture a utility's willingness to accept a given level of risk, plan for it, and invoke a management strategy during extreme events than build a facility to accommodate those in planning for new water supply sources. Accounting for uncertainties in both supply and demand help quantify reliability by achieving a prescribed level of service. The major benefit of such an approach for planning future water supply is that it allows policy makers to evaluate the use of adaptive water management strategies and develop supply in an incremental fashion as demand warrants it. For example, if a given level of service cannot be reliably met with the existing system at a future time t, an incremental water supply project would come online to bring the required reliability level up but no more.     

International perspectives on the implementation of reproductive carrier screening

Reproductive carrier screening started in some countries in the 1970s for hemoglobinopathies and Tay-Sachs disease. Cystic fibrosis carrier screening became possible in the late 1980s and with technical advances, screening of an ever increasing number of genes has become possible. The goal of carrier screening is to inform people about their risk of having children with autosomal recessive and X-linked recessive disorders, to allow for informed decision making about reproductive options. The consequence may be a decrease in the birth prevalence of these conditions, which has occurred in several countries for some conditions. Different programs target different groups (high school, premarital, couples before conception, couples attending fertility clinics, and pregnant women) as does the governance structure (public health initiative and user pays). Ancestry-based offers of screening are being replaced by expanded carrier screening panels with multiple genes that is independent of ancestry. This review describes screening in Australia, Cyprus, Israel, Italy, Malaysia, the Netherlands, Saudi Arabia, the United Kingdom, and the United States. It provides an insight into the enormous variability in how reproductive carrier screening is offered across the globe. This largely relates to geographical variation in carrier frequencies of genetic conditions and local health care, financial, cultural, and religious factors.     

Behavioral changes in fish exposed to phytoestrogens

We investigated the behavioral effects of exposure to waterborne phytoestrogens in male fighting fish, Betta splendens. Adult fish were exposed to a range of concentrations of genistein, equol, beta-sitosterol, and the positive control 17beta-estradiol. The following behaviors were measured: spontaneous swimming activity, latency to respond to a perceived intruder (mirror reflection), intensity of aggressive response toward a perceived intruder, probability of constructing a nest in the presence of a female, and the size of the nest constructed. We found few changes in spontaneous swimming activity, the latency to respond to the mirror, and nest size, and modest changes in the probability of constructing a nest. There were significant decreases, however, in the intensity of aggressive behavior toward the mirror following exposure to several concentrations, including environmentally relevant ones, of 17beta-estradiol, genistein, and equol. This suggests that phytoestrogen contamination has the potential to significantly affect the behavior of free-living fishes.