3,796 research outputs found
Examining Permeability and Contractility of Skeletal Muscle in Castrated Male Mice
A common method of treating skeletal muscle injury is temperature therapy. Temperature affects one of the initial aspects of skeletal muscle healing, the increasing of vascular permeability. Previous data accumulated from the Ursinus College Skeletal Muscle Lab suggests that vascular permeability following temperature therapy is different between the anatomically intact male and female mice. However, there have not been any studies to date that are able determine the cause of these permeability differences following temperature treatment. In addition, it is currently unclear how increased vascular permeability affects skeletal muscle healing. A possible cause for these differences is the increased presence of testosterone in males compared to females. To investigate this, temperature therapy was conducted on 4 castrated male mice with four other castrated male mice as the control group. Moreover, the contractility differences in healed muscle in these mice was to be examined. However, due to unforeseen circumstances, the results for this experiment are limited. This paper will focus more on the methods and future plans of my experiment should it be conducted in full
Improving Biocompatibility By Controlling Protein Adsorption: Modification And Design Of Biomaterials Using Poly(Ethylene Glycol) Microgels And Microspheres
Guided by the clinical needs of patients and developments in biology and materials science, the primary focus of the biomaterials field remains at the solid/liquid interface between biomaterial surfaces and biological fluids. For blood-contacting devices, biological responses are initially elicited and directed by proteins that adsorb from this multicomponent solution to form thin films on their surfaces. The identity, conformation, and quantity of adsorbed proteins are related to the properties of a material\u27s surface. For example, hydrophobic surfaces tend to be thrombotic via interactions between platelets and adsorbed fibrinogen, while surface-activation of specific enzymes initiates the coagulation cascade on hydrophilic surfaces. The objective of this thesis is to improve the design of biomaterials through the analysis and control of adsorbing protein layers. This goal is approached through three separate strategies. First, a proteomics-based methodology is presented for the assessment of protein conformation at the residue level after adsorption to biomaterial surfaces. A quantitative mass spectrometric technique is additionally suggested for the identification and quantification of proteins within adsorbed protein layers. Second, a method is described for the covalent attachment of poly(ethylene glycol): PEG)-based hydrogel coatings onto biomaterials surfaces for the minimization of protein adsorption. The coatings are applied using partially crosslinked PEG solutions containing polymer and protein oligomers and microgels that can be designed to control cell adhesion. Finally, a modular strategy is proposed for the assembly of bioactive PEG-based hydrogel scaffolds. This was accomplished using novel PEG microspheres with diverse characteristics that individually contribute to the ability of the scaffold to direct cellular infiltration. The methodologies proposed by this thesis contribute to the recent shift in biomaterials and tissue engineering strategies towards directed cellular responses at the molecular level
Debris Flow Fans in Yosemite Valley National Park, California
Formation of debris flow fans poses a potential hazard to the infrastructure and inhabitants of Yosemite Valley. Research was conducted on debris flow fans at three field sites in Yosemite Valley: Indian Creek, Eagle Creek, and Sentinel Creek. The study utilized a Trimble Pro XR Differential Global Positioning System (DGPS), Cosmogenic Berellium-10 (10Be) dating, and debris flow volume measurements to better understand the spatial distribution, age, and magnitude of prehistoric debris flow deposits at each field site. It is hypothesized that all three fans were constructed quickly after the last glacial maximum (LGM), which is dated at 19.8 ka. It is also proposed that increased rainfall and sediment production during the LGM provided the necessary conditions for debris flow initiation in each catchment. Future debris flow initiation is contingent on channels being pre-loaded with sediment and above average rainfall. At the present time, the channels are loaded with debris, but future debris flow initiation seems unlikely to occur because the fans have been inactive for thousands of years. Debris flows only pose a significant hazard to Yosemite Valley, if and when, the optimum conditions are met
A Comparative Content Analysis Of African American And Caucasian Role Portrayals In Broadcast Television Entertainment Programming
This study examines the nature and number of character portrayals in broadcast entertainment programming. More specifically, the portrayals of African American characters are examined and compared to Caucasian portrayals. The goal of this study is to determine what, if any, stereotypes may still be prevalent on broadcast television and if there are any discrepancies between portrayals of African American and Caucasian characters.
A content analysis methodology was utilized to code 577 character occurrences from broadcast television entertainment programs popular with African Americans and Caucasian audiences. Each character occurrence was evaluated using thirty-two schematic differential items with regard to portrayal attributes, physical characteristics, behavioral characteristics, appearance characteristics, and the five factor model of personality elements. T-test and z-score analysis were used to determine significant differences between items.
Results determined that African American characters were not portrayed in a negative manner when compared to Caucasian characters. African American characters were underrepresented on television but were within 2% of their population rate. However, in programming watched by African Americans, they were overrepresented. The most common significantly different characteristics found between African American and Caucasian characters on broadcast entertainment programming were hair color, skin color, amount of makeup and amount of accessories
Imagining a Better Public Health (Law) Response to COVID-19
This Article is not a thorough-going history of the pandemic response. By way of critique and suggesting a way forward for public health, we are going to imagine how public health—both the official agencies and the interconnected nodes in academia and health systems—might have approached COVID-19 differently. This is a story that focuses on good judgment as the lynchpin of optimal pandemic response and allows us to think about where good judgment seems to have been lacking, and how public health culture and institutions might change to improve the chances of better judgment next time
Towards beating the curse of dimensionality for gravitational waves using Reduced Basis
Using the Reduced Basis approach, we efficiently compress and accurately
represent the space of waveforms for non-precessing binary black hole
inspirals, which constitutes a four dimensional parameter space (two masses,
two spin magnitudes). Compared to the non-spinning case, we find that only a
{\it marginal} increase in the (already relatively small) number of reduced
basis elements is required to represent any non-precessing waveform to nearly
numerical round-off precision. Most parameters selected by the algorithm are
near the boundary of the parameter space, leaving the bulk of its volume
sparse. Our results suggest that the full eight dimensional space (two masses,
two spin magnitudes, four spin orientation angles on the unit sphere) may be
highly compressible and represented with very high accuracy by a remarkably
small number of waveforms, thus providing some hope that the number of
numerical relativity simulations of binary black hole coalescences needed to
represent the entire space of configurations is not intractable. Finally, we
find that the {\it distribution} of selected parameters is robust to different
choices of seed values starting the algorithm, a property which should be
useful for indicating parameters for numerical relativity simulations of binary
black holes. In particular, we find that the mass ratios of
non-spinning binaries selected by the algorithm are mostly in the interval
and that the median of the distribution follows a power-law behavior
- …