Maternal glucose and fatty acid kinetics and infant birth weight in obese women with type 2 diabetes

The objectives of this study were 1) to describe maternal glucose and lipid kinetics and 2) to examine the relationships with infant birth weight in obese women with pregestational type 2 diabetes during late pregnancy. Using stable isotope tracer methodology and mass spectrometry, maternal glucose and lipid kinetic rates during the basal condition were compared in three groups: lean women without diabetes (Lean, n = 25), obese women without diabetes (OB, n = 26), and obese women with pregestational type 2 diabetes (OB+DM, n = 28; total n = 79). Glucose and lipid kinetics during hyperinsulinemia were also measured in a subset of participants (n = 56). Relationships between maternal glucose and lipid kinetics during both conditions and infant birth weight were examined. Maternal endogenous glucose production (EGP) rate was higher in OB+DM than OB and Lean during hyperinsulinemia. Maternal insulin value at 50% palmitate R(a) suppression (IC50) for palmitate suppression with insulinemia was higher in OB+DM than OB and Lean. Maternal EGP per unit insulin and plasma free fatty acid concentration during hyperinsulinemia most strongly predicted infant birth weight. Our findings suggest maternal fatty acid and glucose kinetics are altered during late pregnancy and might suggest a mechanism for higher birth weight in obese women with pregestational diabetes

Effects of young-growth management on Sitka black-tailed deer in southeast Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2023Commercial logging was the dominant industry in southeast Alaska during the second half of the twentieth century. Logging practices have left a landscape legacy of regenerative forest types such as clearcuts and second growth. Second-growth forest occurs about 20-30 years after a clearcut and is relatively unproductive compared to other forest types. To enhance productivity, second-growth is often thinned to a lower density of standing timber, this process is referred to as pre-commercial thinning (hereafter, thinning). Sitka black-tailed deer (Odocoileus hemionus sitkensis) are an important cultural and subsistence resource across southeast Alaska. How thinned forests affect deer is not well known. To better understand how forest management is affecting local populations of deer in southeast Alaska we examined how thinning treatments impact deer browse intensity and snow accumulation on the forest floor. In this thesis, we presented two studies that examine the effects of thinning on deer habitat quality and deer access to forage. In the first study of this thesis, we quantified browse intensity in recently thinned (≤4 years post thinning) and adjacent old-growth forests. We also explored the immediate effects of thinning and slash (felled trees left on the forest floor) on forage availability. We performed a pairwise comparison of browse intensity between thinned and adjacent old-growth forests and modeled the effects of thinned forest characteristics on browse intensity. In the second study of this thesis, we quantified maximum snow depth in thinned, unthinned second-growth, old-growth and unforested (control) habitat types. Forest structure and composition affected how snow accumulates on the ground. Snow can impede the movement of ungulates species, such as deer, and reduce available forage. We evaluated how different forest types accumulated snow in southeast Alaska to better understand the implications on winter habitat quality for Sitka black-tailed deer. To quantify browse intensity in thinned and adjacent old-growth forests, we conducted browse surveys in recently thinned stands (2017 to 2021) and adjacent middle to high volume old-growth forests. We established 50m transects and surveyed plots every five meters to quantify browse of Vaccinium sp. (blueberry and huckleberry), a preferred deer forage species. In the second study, we measured snow depths throughout thinned, unthinned, old-growth and unforested sites to identify if these forest types accumulate snow differently. We also measured forest structure variables to use as predictors when modeling maximum snow depth. Transects were 70 meters long, and snow depth and forest structure data were collected every five meters. Snow depths were measured four to six times throughout the winter. The maximum depth of each transect point was recorded and paired with the forest structure variables. For both studies, we used nonparametric tests and generalized linear mixed models to understand the interactions between forest types and their maximum snow depths or percent of a Vaccinium sp. plant browsed. From the first study, we concluded that browse intensity was significantly different in thinned and oldgrowth forests (P<0.01). We learned that thinned stands with more slash reduce browse intensity. Slash (vertical obstruction) volume and time since thinning (metrics of slash decay) best explained percent of a plant browsed. From or second study, we found that thinned forests accumulated the same amount of snow on the forest floor as unforested sites. Moreover, old-growth and unthinned sites accumulated snow on the forest floor comparably during a relatively normal snow load year. Our findings regarding browse intensity showed that thinned forests have a delayed benefit to deer because of slash abundance. Our observations regarding snow accumulation showed that thinned forests have little value to deer in a winter with deep snow accumulation. Managers can use this information to better understand the extent of forage available to deer in recently thinned forest habitat. Our findings also demonstrated that the implementation of thinning treatments that minimize slash volume and accelerate decomposition will enhance benefits for deer.PNW Research Station, USDA Natural Resource Conservation Service, the Hoonah Forest PartnershipChapter 1: Introduction -- Chapter 2: Reduced deer browse intensity in pre-commercially thinned forests in Alaska -- Chapter 3: Snow accumulation in pre-commercially thinned forests, and its implications for Sitka black tailed deer (Odocoileus hemionus sitkensis) -- Chapter 4: Conclusion

Picoliter-volume inkjet printing into planar microdevice reservoirs for low-waste, high-capacity drug loading.

Oral delivery of therapeutics is the preferred route for systemic drug administration due to ease of access and improved patient compliance. However, many therapeutics suffer from low oral bioavailability due to low pH and enzymatic conditions, poor cellular permeability, and low residence time. Microfabrication techniques have been used to create planar, asymmetric microdevices for oral drug delivery to address these limitations. The geometry of these microdevices facilitates prolonged drug exposure with unidirectional release of drug toward gastrointestinal epithelium. While these devices have significantly enhanced drug permeability in vitro and in vivo, loading drug into the micron-scale reservoirs of the devices in a low-waste, high-capacity manner remains challenging. Here, we use picoliter-volume inkjet printing to load topotecan and insulin into planar microdevices efficiently. Following a simple surface functionalization step, drug solution can be spotted into the microdevice reservoir. We show that relatively high capacities of both topotecan and insulin can be loaded into microdevices in a rapid, automated process with little to no drug waste

Simulation of alternative male reproductive behavior: calling and satellite behavior in field crickets.

Male field crickets and other acoustically communicating insects call and attract females and silently intercept females attracted by the calling of other males, so-called satellite behavior. A simulation of field cricket, Gryllus integer, mating behavior suggests that population density and sex ratio changes during the breeding season are important factors determining mating success of calling and satellite males. Satellite mating success increased with the proportion of satellite males, but mating success of callers was independent of the proportion of calling males. Satellite male mating success was greatest in high density populations with extremely female-biased sex ratios. Calling males also mated more often under most population densities, various populations differing in the proportion of callers and in sex ratios. Calling male mating advantage decayed exponentially, however, with increasing population density. Variation in male G. integer reproductive behavior has previously been associated with fluctuating population densities in empirical studies on laboratory and field populations. The simulation suggests that variation in male mating success with the operational sex ratio also contributes to the continuing existence of alternative male reproductive behavior. Predictions derived from the simulation can be tested in actual populations of G. integer and other species

Indoor free-space optical communication enhanced by dynamic optical beam control

This work expands the field of indoor free-space optical communication by introducing novel techniques in short range optical communication. The increasing need for high bandwidth communication necessitates the transition to optical frequencies with hundreds of terahertz worth of unregulated bandwidth. Optical communication offers an inherent security advantage over traditional communications methods by utilizing line-of-sight data transmission. First, we experimentally demonstrate a 1Gb/s, dynamically adjustable, all-optical communication system capable of securely locating and transmitting data to a static user in the field of view (FOV). Second, we propose and lay the foundation for a 10Gb/s, optical communication system capable of tracking and sending data to a user in the field of view

Multi-Grand, Multi-Canonical, Flat Histogram, Monte Carlo Simulations for the Square Well Fluid

Currently multi-canonical, and grand canonical Monte Carlo simulations exist, but do not always give all of the necessary information of the system. When using a 1-D (only changing in one variable) broad histogram Monte Carlo method a user would need to run a range of simulations in order to get the data necessary for generating the equation of state. In our multi-grand, multi-canonical approach we demonstrate the effectiveness of a ``2-D" broad histogram simulation. The M-G, M-C Monte Carlo allows for both a change in the energy and the number of atoms in a square well fluid. The multiple degrees of change allow for the calculation of the entire equation of state from only one simulation