5,676 research outputs found
Flood Survival Strategies of Overwintering Snakes
This thesis investigates snake flood survival during hibernation and how anthropogenic habitat alteration and climate variability may affect habitat quality and overwintering survival.
Chapter one reviews the current understanding of ecophysiology of hibernation in snakes. In chapter two, I introduce a winter habitat model of a subterranean space that remains flood and frost-free, referred to as the “life zone,” where snakes survive winter. I analyzed 11- winters of hibernation habitat data and 18-yrs of population mark-recapture data to assess the effects of the first flood event on an endangered Massasauga population. Following the flood event, snake observations declined despite hundreds of hours of search-effort. At the population level this was evidence of poor winter survival and recruitment post flood. The direct cause of mortality was not determined but poor winter survival in areas with a depleted life zone was statistically supported.
In the third chapter, I measured the metabolic rate (M ̇_(O_2 )) at 5°C for three snake species that inhabit my study area. I varied water level conditions and measured activity and dive behaviours continuously during experiments. I found differences between species in their resting metabolic rate, which I attributed to body size differences. I confirmed, cutaneous respiration occurs at a low rate and was significantly upregulated during a forced dive (flood event). Therefore, there is an intrinsic physiological response to a flood event in neonatal snakes. However, post-flood recovery indicated a greater oxygen demand after the short-forced dive. An oxygen debt was incurred during a short-forced dive under normoxic conditions. My conclusions are, 1) hibernation habitat (i.e., life zone) must include a non-freezing, non-flooding aerobic space throughout winter to maintain snake survival. 2) cutaneous respiration is a short-term flood survival strategy. I found no support for a complete aquatic hibernation strategy 3) the energy costs of a full-dive is additive to the recovery energetic costs of a flood event. A neonatal snake wintering energy budget is proposed, and winter mortality conservation issues are discussed in chapter 4
A relationship between slide quality and image quality in whole slide imaging (WSI)
This study examined the effect of tissue section thickness and consistency – parameters outside the direct control of the imaging devices themselves – on WSI capture speed and image quality. Preliminary data indicates that thinner, more consistent tissue sectioning (such as those produced by automated tissue sectioning robots) result in significantly faster WSI capture times and better image quality
The importance of optical optimization in whole slide imaging (WSI) and digital pathology imaging
In the last 10 years, whole slide imaging (WSI) has seen impressive progress not only in image quality and scanning speed but also in the variety of systems available to pathologists. However, we have noticed that most systems have relatively simple optics axes and rely on software to optimize image quality and colour balance. While much can be done in software, this study examines the importance of optics, in particular optical filters, in WSI
Forage Quality, Yield and Palatability of Quackgrass (\u3ci\u3eElytrigia repens\u3c/i\u3e (L.) Nevski)
Quackgrass (Elytrigia repens (L.) Nevski) is a competitive perennial invader of pastures and hay meadows which is frequently harvested as forage in mixtures with desired forage species. Field experiments were conducted to compare quackgrass with cool-season perennial grasses grown under the same soil and climatic conditions, in terms of forage quality, productivity, and palatability. The forage quality of the hays was influenced by the grass species. Quackgrass showed forage crude protein (CP) concentration that was equal to those of perennial ryegrass (Lolium perenne), reed canarygrass (Phalaris arundinacea) and Kentucky bluegrass (Poa pratensis), and greater than orchardgrass (Dactylis glomerata). The neutral detergent fiber (NDF) acid detergent fiber (ADF) concentration of the quackgrass was intermediate between those of perennial ryegrass and Kentucky bluegrass. Yields of quackgrass was equal to reed canarygrass, and greater than those of Kentucky bluegrass, orchardgrass and perennial ryegrass. The different hays did not affect the response of animals by feed intake. Quackgrass hay had higher phosphorus (P) and potassium (K) concentration, and lower calcium (Ca), magnesium (Mg) concentrations. Quackgrass was not to be inferior to other cool-season perennial grasses under frequent utilization
No Immune Responses by the Expression of the Yeast Ndi1 Protein in Rats
Background: The rotenone-insensitive internal NADH-quinone oxidoreductase from yeast, Ndi1, has been shown to work as a replacement molecule for complex I in the respiratory chain of mammalian mitochondria. In the so-called transkingdom gene therapy, one major concern is the fact that the yeast protein is foreign in mammals. Long term expression of Ndi1 observed in rodents with no apparent damage to the target tissue was indicative of no action by the host’s immune system. Methodology/Principal Findings: In the present study, we examined rat skeletal muscles expressing Ndi1 for possible signs of inflammatory or immune response. In parallel, we carried out delivery of the GFP gene using the same viral vector that was used for the NDI1 gene. The tissues were subjected to H&E staining and immunohistochemical analyses using antibodies specific for markers, CD11b, CD3, CD4, and CD8. The data showed no detectable signs of an immune response with the tissues expressing Ndi1. In contrast, mild but distinctive positive reactions were observed in the tissues expressing GFP. This clear difference most likely comes from the difference in the location of the expressed protein. Ndi1 was localized to the mitochondria whereas GFP was in the cytosol. Conclusions/Significance: We demonstrated that Ndi1 expression did not trigger any inflammatory or immune response in rats. These results push forward the Ndi1-based molecular therapy and also expand the possibility of using foreign protein
Influence of Charge and Energy Imbalances on the Tunneling Current through a Superconductor-Normal Metal Junction
We consider quasiparticle charge and energy imbalances in a thin
superconductor weakly coupled with two normal-metal electrodes via tunnel
junctions at low temperatures. Charge and energy imbalances, which can be
created by injecting quasiparticles at one junction, induce excess tunneling
current at the other junction. We numerically obtain
as a function of the bias voltage across the detection junction.
We show that at the zero bias voltage is purely determined by the
charge imbalance, while the energy imbalance causes a nontrivial -dependence of . The obtained voltage-current characteristics
qualitatively agree with the experimental result by R. Yagi [Phys. Rev. B {\bf
73} (2006) 134507].Comment: 10 pages, 5 figure
Determination of Formation Rate Constant of Carrier-Free 111In(III) with EDTA
開始ページ、終了ページ: 冊子体のページ付
Space-time evolution of bulk QCD matter
We introduce a combined fully three-dimensional macroscopic/microscopic
transport approach employing relativistic 3D-hydrodynamics for the early,
dense, deconfined stage of the reaction and a microscopic non-equilibrium model
for the later hadronic stage where the equilibrium assumptions are not valid
anymore. Within this approach we study the dynamics of hot, bulk QCD matter,
which is being created in ultra-relativistic heavy ion collisions at RHIC. Our
approach is capable of self-consistently calculating the freezeout of the
hadronic system, while accounting for the collective flow on the hadronization
hypersurface generated by the QGP expansion. In particular, we perform a
detailed analysis of the reaction dynamics, hadronic freezeout, and transverse
flow.Comment: 24 pages, 27 figure
Action recognition using Kinematics Posture Feature on 3D skeleton joint locations
Action recognition is a very widely explored research area in computer vision and related fields. We propose Kinematics Posture Feature (KPF) extraction from 3D joint positions based on skeleton data for improving the performance of action recognition. In this approach, we consider the skeleton 3D joints as kinematics sensors. We propose Linear Joint Position Feature (LJPF) and Angular Joint Position Feature (AJPF) based on 3D linear joint positions and angles between bone segments. We then combine these two kinematics features for each video frame for each action to create the KPF feature sets. These feature sets encode the variation of motion in the temporal domain as if each body joint represents kinematics position and orientation sensors. In the next stage, we process the extracted KPF feature descriptor by using a low pass filter, and segment them by using sliding windows with optimized length. This concept resembles the approach of processing kinematics sensor data. From the segmented windows, we compute the Position-based Statistical Feature (PSF). These features consist of temporal domain statistical features (e.g., mean, standard deviation, variance, etc.). These statistical features encode the variation of postures (i.e., joint positions and angles) across the video frames. For performing classification, we explore Support Vector Machine (Linear), RNN, CNNRNN, and ConvRNN model. The proposed PSF feature sets demonstrate prominent performance in both statistical machine learning- and deep learning-based models. For evaluation, we explore five benchmark datasets namely UTKinect-Action3D, Kinect Activity Recognition Dataset (KARD), MSR 3D Action Pairs, Florence 3D, and Office Activity Dataset (OAD). To prevent overfitting, we consider the leave-one-subject-out framework as the experimental setup and perform 10-fold cross-validation. Our approach outperforms several existing methods in these benchmark datasets and achieves very promising classification performance
- …