This paper explores the effects of lake evaporation and precipitation, reliability levels, and streamflow probability distribution on reservoir capacity and average release. A series of reservoir-analysis deterministic and stochastic models of increasing complexity are employed to examine these effects, which are illustrated using a mid-sized reservoir in Santa Barbara County, California. The deterministic reservoir models show evaporation dominating reservoir water balance, and, for the most part determining optimal reservoir capacity and annual releases, whereby comparatively larger reservoirs are required to compensate for the water lost to evaporation. The more complex stochastic models use chance constraints and bootstrapped reservoir inflow probability distributions, and suggest that optimal capacity and annual releases are dominated by reliability levels, with very large optimal reservoir capacities and annual releases required when the reliability levels approach one. Copyright ASCE 2006.

There is a limit beyond which increasing either the concentration of a prostaglandin analog (PGA) or its dosing frequency fails to produce increases in ocular hypotensive efficacy with topical dosing. Intracameral PGA dosing with a bimatoprost implant, however, does not exhibit the same intraocular pressure (IOP)-lowering plateau at studied concentrations, and the maximum-achievable ocular hypotensive effects are not yet known. This suggests that the bimatoprost intracameral implant may activate another mechanism of action in addition to the mechanism(s) activated by topical application. Episcleral venous pressure (EVP) is a key determinant of IOP, and experimental manipulation of the episcleral vasculature can change both EVP and IOP. The recent observation that topical and intracameral PGA drug delivery routes produce different patterns of conjunctival hyperemia suggested that the differences in the IOP-lowering profiles may be caused by differing effects on the episcleral vasculature. Recent experiments in animals have shown that topical PGAs increase EVP, while the bimatoprost intracameral implant causes a smaller, transient increase in EVP, followed by a sustained decrease. The increase in EVP could be limiting the IOP-lowering efficacy of topical PGAs. In contrast, the decrease in EVP associated with the bimatoprost implant could explain its enhanced IOP-lowering effects. Further research on EVP as a target for IOP lowering is indicated to improve our understanding of this potentially important pathway for treating patients with glaucoma.

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that degrade extracellular matrix (ECM) components such as collagen and have important roles in multiple biological processes, including development and tissue remodeling, both in health and disease. The activity of MMPs is influenced by the expression of MMPs and tissue inhibitors of metalloproteinase (TIMPs). In the eye, MMP-mediated ECM turnover in the juxtacanalicular region of the trabecular meshwork (TM) reduces outflow resistance in the conventional outflow pathway and helps maintain intraocular pressure (IOP) homeostasis. An imbalance in the MMP/TIMP ratio may be involved in the elevated IOP often associated with glaucoma. The prostaglandin analog/prostamide (PGA) class of topical ocular hypotensive medications used in glaucoma treatment reduces IOP by increasing outflow through both conventional and unconventional (uveoscleral) outflow pathways. Evidence from in vivo and in vitro studies using animal models and anterior segment explant and cell cultures indicates that the mechanism of IOP lowering by PGAs involves increased MMP expression in the TM and ciliary body, leading to tissue remodeling that enhances conventional and unconventional outflow. PGA effects on MMP expression are dependent on the identity and concentration of the PGA. An intracameral sustained-release PGA implant (Bimatoprost SR) in development for glaucoma treatment can reduce IOP for many months after expected intraocular drug bioavailability. We hypothesize that the higher concentrations of bimatoprost achieved in ocular outflow tissues with the implant produce greater MMP upregulation and more extensive, sustained MMP-mediated target tissue remodeling, providing an extended duration of effect.

The determinants of buyer-seller negotiations in four cultures are investigated in a laboratory simulation. One hundred thirty-eight American, 54 Chinese, 42 Japanese, and 38 Korean business people participated in a two-person, buyer-seller, intracultural negotiation simulation. In negotiations between Americans, the use of more problem-solving bargaining strategies positively influenced negotiation outcomes. In negotiations between Chinese, more competitive strategies led to better results. In Japanese and Korean negotiations, buyers achieved higher economic rewards than sellers. In all four cultures, bargainers were more satisfied with negotiation outcomes when partners were rated more attractive. The primary purpose of the study is to determine if face-to-face, buyer-seller negotiation processes vary across three Asian cultures. Specifically, the validity of generalizations about Oriental behavior are called to question by comparing simulated negotiations of Japanese, Korean, and Chinese (Taiwanese) business people. American buyer-seller negotiation processes are also examined and discussed in relation to the three Asian cultures.

Purpose: To evaluate the time course of biodegradation of an intracameral, biodegradable, sustained-release bimatoprost implant that lowers intraocular pressure without the need for daily eye drops. Methods: In 2 identically designed, randomized, phase 3 clinical trials, adults with open-angle glaucoma or ocular hypertension and open iridocorneal angles inferiorly in the study eye were administered 10- or 15-μg bimatoprost implant (day 1 and weeks 16 and 32) or twice-daily topical timolol 0.5%. Implants were assessed on gonioscopy throughout the studies. Investigators reported whether implants were visible, estimated the size of visible implants relative to their initial size at implantation, and reported the implant location. Data for 10-μg implant placed on day 1 were pooled from both studies for analysis. Results: A total of 372 patients received the 10-μg bimatoprost implant. The degree of implant biodegradation at each follow-up time point was variable among patients. The implant frequently swelled during the initial phase of biodegradation from 6 to 28 weeks. Accelerated biodegradation occurred between 31 and 52 weeks, resulting in 82% of implants absent or ≤25% of initial size by 52 weeks. By month 20, 95% of implants had biodegraded to absent or ≤25% of initial size. The implant was predominantly located inferiorly in the iridocorneal angle. Conclusions: Bimatoprost implant biodegradation in phase 3 studies showed some degree of variability among patients. Clinically significant implant biodegradation was observed in the majority of patients by 12 months. Clinical studies are in progress to further understand implant biodegradation and the ideal timing for implant re-administration. ClinicalTrials.gov NCT02247804; ClinicalTrials.gov NCT02250651.

Purpose

To assess the intraocular pressure (IOP)-lowering effects of bimatoprost sustained-release implant (BimSR) in normotensive monkeys receiving topical bimatoprost.

Methods

Six eyes from six female, normotensive, cynomolgus monkeys were treated with once-daily topical latanoprost 0.005% plus twice-daily fixed-combination dorzolamide 2%/timolol 0.5%. At week 5, topical latanoprost was switched to once-daily topical bimatoprost 0.03% and twice-daily dorzolamide 2%/timolol 0.5% was continued. At week 8, BimSR 20 μg was administered intracamerally to three eyes and topical therapy was continued in all eyes. At week 12, all topical therapy was discontinued and animals were monitored for another 4 weeks. IOP was measured with a TonoVet rebound tonometer in nonsedated animals weekly for 16 weeks.

Results

Average mean (standard deviation) IOP was 19.8 (1.6) mm Hg at baseline, 15.7 (0.9) mm Hg during treatment with topical latanoprost/dorzolamide/timolol from weeks 1 to 5, and 14.2 (0.5) mm Hg during weeks 6 to 8 after topical latanoprost was switched to topical bimatoprost. After BimSR was added, average mean IOP during weeks 9 to 12 was 10.8 (1.3) mm Hg, a decrease of 3.9 mm Hg compared with the topical-only arm. When topical therapy was discontinued, IOP in BimSR-treated eyes remained below that in unmedicated eyes (15.8 [0.9] vs. 20.2 [0.2] mm Hg at weeks 14-16).

Conclusions

Intracameral BimSR has IOP-lowering effects additive to those of topical bimatoprost, suggesting an additional mechanism of action with intracameral drug delivery.

Translational relevance

Compared with topical bimatoprost, intracameral BimSR may have an additional mechanism of action of IOP lowering.

Background

Despite a number of different transgenes that can mediate DNA deletion in the developing lens, each has unique features that can make a given transgenic line more or less appropriate for particular studies. The purpose of this work encompasses both a review of transgenes that lead to the expression of Cre recombinase in the lens and a comparative analysis of currently available transgenic lines with a particular emphasis on the Le-Cre and P0-3.9GFPCre lines that can mediate DNA deletion in the lens placode. Although both of these transgenes are driven by elements of the Pax6 P0 promoter, the Le-Cre transgene consistently leads to ocular abnormalities in homozygous state and can lead to ocular defects on some genetic backgrounds when hemizygous.

Result

Although both P0-3.9GFPCre and Le-Cre hemizygous transgenic mice undergo normal eye development on an FVB/N genetic background, Le-Cre homozygotes uniquely exhibit microphthalmia. Examination of the expression patterns of these two transgenes revealed similar expression in the developing eye and pancreas. However, lineage tracing revealed widespread non-ocular CRE reporter gene expression in the P0-3.9GFPCre transgenic mice that results from stochastic CRE expression in the P0-3.9GFPCre embryos prior to lens placode formation. Postnatal hemizygous Le-Cre transgenic lenses express higher levels of CRE transcript and protein than the hemizygous lenses of P0-3.9GFPCre mice. Transcriptome analysis revealed that Le-Cre hemizygous lenses deregulated the expression of 15 murine genes, several of which are associated with apoptosis. In contrast, P0-3.9GFPCre hemizygous lenses only deregulated two murine genes. No known PAX6-responsive genes or genes directly associated with lens differentiation were deregulated in the hemizygous Le-Cre lenses.

Conclusions

Although P0-3.9GFPCre transgenic mice appear free from ocular abnormalities, extensive non-ocular CRE expression represents a potential problem for conditional gene deletion studies using this transgene. The higher level of CRE expression in Le-Cre lenses versus P0-3.9GFPCre lenses may explain abnormal lens development in homozygous Le-Cre mice. Given the lack of deregulation of PAX6-responsive transcripts, we suggest that abnormal eye development in Le-Cre transgenic mice stems from CRE toxicity. Our studies reinforce the requirement for appropriate CRE-only expressing controls when using CRE as a driver of conditional gene targeting strategies.

In the established model of mammalian cell cycle control, the retinoblastoma protein (Rb) functions to restrict cells from entering S phase by binding and sequestering E2f activators (E2f1, E2f2 and E2f3), which are invariably portrayed as the ultimate effectors of a transcriptional program that commit cells to enter and progress through S phase. Using a panel of tissue-specific cre-transgenic mice and conditional E2f alleles we examined the effects of E2f1, E2f2 and E2f3 triple deficiency in murine embryonic stem cells, embryos and small intestines. We show that in normal dividing progenitor cells E2f1-3 function as transcriptional activators, but contrary to the current view, are dispensable for cell division and instead are necessary for cell survival. In differentiating cells E2f1-3 function in a complex with Rb as repressors to silence E2f targets and facilitate exit from the cell cycle. The inactivation of Rb in differentiating cells resulted in a switch of E2f1-3 from repressors to activators, leading to the superactivation of E2f responsive targets and ectopic cell divisions. Loss of E2f1-3 completely suppressed these phenotypes caused by Rb deficiency. This work contextualizes the activator versus repressor functions of E2f1-3 in vivo, revealing distinct roles in dividing versus differentiating cells and in normal versus cancer-like cell cycles.

Progress in addressing the origins of intellectual and developmental disabilities accelerated with the establishment 50 years ago of the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health and associated Intellectual and Developmental Disabilities Research Centers. Investigators at these Centers have made seminal contributions to understanding human brain and behavioral development and defining mechanisms and treatments of disorders of the developing brain. ANN NEUROL 2019;86:332-343.