Movement of Smallmouth Bass within the Beaver Island Archipelago, Northern Lake Michigan.

Fish movement may vary across a wide array of aquatic ecosystems and may be related to the overall size of the system inhabited. We investigated movement of smallmouth bass in Lake Michigan because this information is lacking for larger systems. A total of 16 smallmouth bass were surgically implanted with ultrasonic transmitters within the Beaver Archipelago, northern Lake Michigan. During 2007–2008, a maximum of one location per individual was recorded daily during three specific tracking periods – pre-spawn, spawning, and post-spawn – to determine diurnal movement patterns. Movement was evaluated as site fidelity, minimum displacement rate,maximumexcursion rate, and distance from shore. Smallmouth bass exhibited greatermaximum excursion rates during the spawn period compared to pre-spawn. Movement rates did not differ between tracking periods; however, movement rates were greater during the spawn period in 2007 than 2008. Both sexes moved further offshore to deeper water during post-spawn, but females were located further offshore than males during this period. Annual site fidelity was more evident during post-spawn than during spawning for both sexes. Two smallmouth bass emigrated outside of the Archipelago, suggesting this population may be more “open” in terms of individuals moving throughout northern Lake Michigan than previously thought. These results indicate smallmouth bass may move greater distances in larger aquatic systems and therefore larger management units (in terms of total area) should be established in Lake Michigan to account for these greater excursion distances

Movement of Smallmouth Bass within the Beaver Island Archipelago, Northern Lake Michigan.

Fish movement may vary across a wide array of aquatic ecosystems and may be related to the overall size of the system inhabited. We investigated movement of smallmouth bass in Lake Michigan because this information is lacking for larger systems. A total of 16 smallmouth bass were surgically implanted with ultrasonic transmitters within the Beaver Archipelago, northern Lake Michigan. During 2007–2008, a maximum of one location per individual was recorded daily during three specific tracking periods – pre-spawn, spawning, and post-spawn – to determine diurnal movement patterns. Movement was evaluated as site fidelity, minimum displacement rate,maximumexcursion rate, and distance from shore. Smallmouth bass exhibited greatermaximum excursion rates during the spawn period compared to pre-spawn. Movement rates did not differ between tracking periods; however, movement rates were greater during the spawn period in 2007 than 2008. Both sexes moved further offshore to deeper water during post-spawn, but females were located further offshore than males during this period. Annual site fidelity was more evident during post-spawn than during spawning for both sexes. Two smallmouth bass emigrated outside of the Archipelago, suggesting this population may be more “open” in terms of individuals moving throughout northern Lake Michigan than previously thought. These results indicate smallmouth bass may move greater distances in larger aquatic systems and therefore larger management units (in terms of total area) should be established in Lake Michigan to account for these greater excursion distances

Fish Assemblage Shifts and Population Dynamics of Smallmouth Bass (Micropterus dolomieu) in the Beaver Archipelago, Northern Lake Michigan: A Comparison Between Historical and Recent Time Periods Amidst Ecosystem Changes.

The ecological and economic importance of Great Lakes nearshore areas and the paucity of information on nearshore Lake Michigan fish assemblages prompted us to document changes that occurred from a historical time period (1969–1972, 1975, 1977, and 1984) to a recent period (2005–2008) in a nearshore northern Lake Michigan (Beaver Archipelago) fish assemblage, with an emphasis on smallmouth bass Micropterus dolomieu. From historical to recent periods, the Beaver Archipelago fish assemblage shifted from predominantly brown bullheads Ameiurus nebulosus to predominantly smallmouth bass. Relative abundance of brown bullheads and white suckers Catostomus commersonii declined from historical to recent time periods, as did overall species richness. The relative abundance, recruitment variability, and mortality rates of smallmouth bass have not significantly changed since the historical time period, whereas both condition (ages 5–7) and growth (ages 2–7) of this species have significantly increased. Our results suggest that the smallmouth bass population in the Beaver Archipelago area has not been negatively affected by recent ecological changes (i.e., declining primary productivity, increasing benthic invertebrate densities, increasing numbers of double-crested cormorants Phalacrocorax auritus, and increasing introductions of nonnative species). The smallmouth bass is currently the dominant nearshore species and remains a critical component of the nearshore fish assemblage in northern Lake Michigan

Induced Pluripotent Stem Cell-Derived Retinal Pigmented Epithelium: A Comparative Study Between Cell Lines and Differentiation Methods

PurposeThe application of induced pluripotent stem cell-derived retinal pigmented epithelium (iPSC-RPE) in patients with retinal degenerative disease is making headway toward the clinic, with clinical trials already underway. Multiple groups have developed methods for RPE differentiation from pluripotent cells, but previous studies have shown variability in iPSC propensity to differentiate into RPE.MethodsThis study provides a comparison between 2 different methods for RPE differentiation: (1) a commonly used spontaneous continuously adherent culture (SCAC) protocol and (2) a more rapid, directed differentiation using growth factors. Integration-free iPSC lines were differentiated to RPE, which were characterized with respect to global gene expression, expression of RPE markers, and cellular function.ResultsWe found that all 5 iPSC lines (iPSC-1, iPSC-2, iPSC-3, iPSC-4, and iPSC-12) generated RPE using the directed differentiation protocol; however, 2 of the 5 iPSC lines (iPSC-4 and iPSC-12) did not yield RPE using the SCAC method. Both methods can yield bona fide RPE that expresses signature RPE genes and carry out RPE functions, and are similar, but not identical to fetal RPE. No differences between methods were detected in transcript levels, protein localization, or functional analyses between iPSC-1-RPE, iPSC-2-RPE, and iPSC-3-RPE. Directed iPSC-3-RPE showed enhanced transcript levels of RPE65 compared to directed iPSC-2-RPE and increased BEST1 expression and pigment epithelium-derived factor (PEDF) secretion compared to directed iPSC-1-RPE. In addition, SCAC iPSC-3-RPE secreted more PEDF than SCAC iPSC-1-RPE.ConclusionsThe directed protocol is a more reliable method for differentiating RPE from various pluripotent sources and some iPSC lines are more amenable to RPE differentiation

Engineering biomimetic scaffolds to encapsulate adipose-derived stem cells: A cell biology approach to regenerative treatments

The last decade has seen tremendous advances in the use of stem cell-based therapies to treat injury and disease, yet there are many hurdles still to overcome. Tissue or organ-specific strategies have begun to emerge as our knowledge of stem cell biology and transplant biology increases. This thesis presents results aimed at understanding and improving cell based therapies for soft tissue repair. Defects in soft-tissue can occur by many means, including traumatic injury, tumor resection, and congenital causes. Current approaches to the treatment of these deficiencies include autologous fat transplantation, which falls short of optimal. There are numerous negative outcomes associated with this procedure, the most common of which is loss of transplanted volume; which occurs in 92% of cases. This thesis describes efforts to improve autologous treatments by utilizing the stem cell population present in transplanted tissue, adipose-derived stem cells (ASCs), and encapsulating them in an environment that supports survival, improving treatment options. The following chapters provide an in-depth overview of the development of a synthetic scaffolding system that supports the survival and differentiation of ASCs in vitro. By utilizing poly(ethylene) glycol (PEG) we were able to model a biomimetic environment and demonstrate that functionalization of inert PEG with different Arg-Gly-Asp (RGD)-containing peptides resulted in different levels of adhesion. After the development of the scaffolding system we sought to further engineer capabilities of the system to provide the possibility for numerous applications using the same basic chemistry. Capitalizing on what is known about the remodeling of natural extracellular matrix (ECM) we were able to incorporate peptides that permit the degradation of the scaffolding after the stem cells differentiate. Selecting a cleavage sequence that is sensitive to proteinases that are secreted by mature adipocyte and not by undifferentiated ASCs we succeeded in creating a hydrogel that mimics a natural environment and is degradable upon the differentiation of ASCs to the desired cell types. We have further demonstrated that ASCs encapsulated in this system are viable for 12 weeks, both in vitro and in vivo. Although we examined just adipogenic differentiation in this work, due to the simple nature of the system it should be possible to systematically alter the incorporated components for applications of other cell types. This affords extensive possible targets for tissue regeneration utilizing a basic scaffolding system. Collectively, the work described here advances the understanding and application of stem cell based therapies for soft tissue repair and regeneration

Fish Assemblage Shifts and Population Dynamics of Smallmouth Bass (Micropterus dolomieu) in the Beaver Archipelago, Northern Lake Michigan: A Comparison Between Historical and Recent Time Periods Amidst Ecosystem Changes.

The ecological and economic importance of Great Lakes nearshore areas and the paucity of information on nearshore Lake Michigan fish assemblages prompted us to document changes that occurred from a historical time period (1969–1972, 1975, 1977, and 1984) to a recent period (2005–2008) in a nearshore northern Lake Michigan (Beaver Archipelago) fish assemblage, with an emphasis on smallmouth bass Micropterus dolomieu. From historical to recent periods, the Beaver Archipelago fish assemblage shifted from predominantly brown bullheads Ameiurus nebulosus to predominantly smallmouth bass. Relative abundance of brown bullheads and white suckers Catostomus commersonii declined from historical to recent time periods, as did overall species richness. The relative abundance, recruitment variability, and mortality rates of smallmouth bass have not significantly changed since the historical time period, whereas both condition (ages 5–7) and growth (ages 2–7) of this species have significantly increased. Our results suggest that the smallmouth bass population in the Beaver Archipelago area has not been negatively affected by recent ecological changes (i.e., declining primary productivity, increasing benthic invertebrate densities, increasing numbers of double-crested cormorants Phalacrocorax auritus, and increasing introductions of nonnative species). The smallmouth bass is currently the dominant nearshore species and remains a critical component of the nearshore fish assemblage in northern Lake Michigan

Strategies for bioengineered scaffolds that support adipose stem cells in regenerative therapies.

Regenerative medicine possesses the potential to ameliorate damage to tissue that results from a vast range of conditions, including traumatic injury, tumor resection and inherited tissue defects. Adult stem cells, while more limited in their potential than pluripotent stem cells, are still capable of differentiating into numerous lineages and provide feasible allogeneic and autologous treatment options for many conditions. Adipose stem cells are one of the most abundant types of stem cell in the adult human. Here, we review recent advances in the development of synthetic scaffolding systems used in concert with adipose stem cells and assess their potential use for clinical applications

Strategies for bioengineered scaffolds that support adipose stem cells in regenerative therapies.

Regenerative medicine possesses the potential to ameliorate damage to tissue that results from a vast range of conditions, including traumatic injury, tumor resection and inherited tissue defects. Adult stem cells, while more limited in their potential than pluripotent stem cells, are still capable of differentiating into numerous lineages and provide feasible allogeneic and autologous treatment options for many conditions. Adipose stem cells are one of the most abundant types of stem cell in the adult human. Here, we review recent advances in the development of synthetic scaffolding systems used in concert with adipose stem cells and assess their potential use for clinical applications