Blood and tissue distribution of gamma glutamyl transferase in calves.

In five male and five female calves, we studied the tissue distribution of gamma-glutamyl transferase. The enzyme was mainly in kidney, pancreas, and liver; there was no sex-related difference. The relative hepatic and pancreatic specificity of the enzyme indicated that the measure of its activity in serum could be a test of hepatic or pancreatic damage in the calf. Serum activity measured within 159 samples of apparently healthy calves was 15.3 +/- 3.7 U/liter, not differing significantly from that of adult cow.     

Automated design of error-resilient and hardware-efficient deep neural networks

Applying deep neural networks (DNNs) in mobile and safety-critical systems, such as autonomous vehicles, demands a reliable and efficient execution on hardware. The design of the neural architecture has a large influence on the achievable efficiency and bit error resilience of the network on hardware. Since there are numerous design choices for the architecture of DNNs, with partially opposing effects on the preferred characteristics (such as small error rates at low latency), multi-objective optimization strategies are necessary. In this paper, we develop an evolutionary optimization technique for the automated design of hardware-optimized DNN architectures. For this purpose, we derive a set of inexpensively computable objective functions, which enable the fast evaluation of DNN architectures with respect to their hardware efficiency and error resilience. We observe a strong correlation between predicted error resilience and actual measurements obtained from fault injection simulations. Furthermore, we analyze two different quantization schemes for efficient DNN computation and find one providing a significantly higher error resilience compared to the other. Finally, a comparison of the architectures provided by our algorithm with the popular MobileNetV2 and NASNet-A models reveals an up to seven times improved bit error resilience of our models. We are the first to combine error resilience, efficiency, and performance optimization in a neural architecture search framework.

     

Smoothed Particle Hydrodynamics (SPH) simulation of a high-pressure homogenization process

High-pressure homogenization is a widely used process in the food, pharmaceutical, and cosmetic industry for producing emulsions. Because of small dimensions and high velocities, the experimental and numerical investigation of such a process is challenging. Hence, the development of products is mostly based on trial and error. In this paper, simulations of a generic high-pressure homogenization process using the Lagrangian, mesh-free smoothed particle hydrodynamics (SPH) method are presented and compared to experimental findings using Micro-Particle Image Velocimetry (μ-PIV). The SPH code has been developed and validated with the scope of simulating technical relevant multi-phase problems (Höfler et al. 2012). The present simulations cover the investigation of two different dynamic viscosities of the dispersed phase as well as different droplet trajectories. The comparison between the simulations and the experiments focusses on the velocity distribution of the continuous phase and the droplet deformation and breakup. In both cases a qualitatively good agreement is observed, demonstrating the ability of our SPH implementation for simulating technical relevant two-phase flows.     

Estimation of Detection Thresholds for Redirected Walking Techniques

In immersive virtual environments (IVEs), users can control their virtual viewpoint by moving their tracked head and walking through the real world. Usually, movements in the real world are mapped one-to-one to virtual camera motions. With redirection techniques, the virtual camera is manipulated by applying gains to user motion so that the virtual world moves differently than the real world. Thus, users can walk through large-scale IVEs while physically remaining in a reasonably small workspace. In psychophysical experiments with a two-alternative forced-choice task, we have quantified how much humans can unknowingly be redirected on physical paths that are different from the visually perceived paths. We tested 12 subjects in three different experiments: (E1) discrimination between virtual and physical rotations, (E2) discrimination between virtual and physical straightforward movements, and (E3) discrimination of path curvature. In experiment E1, subjects performed rotations with different gains, and then had to choose whether the visually perceived rotation was smaller or greater than the physical rotation. In experiment E2, subjects chose whether the physical walk was shorter or longer than the visually perceived scaled travel distance. In experiment E3, subjects estimate the path curvature when walking a curved path in the real world while the visual display shows a straight path in the virtual world. Our results show that users can be turned physically about 49 percent more or 20 percent less than the perceived virtual rotation, distances can be downscaled by 14 percent and upscaled by 26 percent, and users can be redirected on a circular arc with a radius greater than 22 m while they believe that they are walking straight.     

Organochlorine insecticides and PCB'S in sediments of Lake St. Claire (1970 and 1974) and Lake Erie (1971).

Sediments were collected on a grid from Lake St. Clair in 1970 and 1974 and from Lake Erie in 1971 and analysed for organochlorine insecticides and PCBs. Suspended solids were centrifuged from pumped water in the Detroit River in 1974. Residues of DDE, TDE and DDT were highest in sediment from the Western Basin (70.3 ppb) Lake Erie and lowest in sediment from Lake St. Clair (6.6 ppb in 1970 and 2.6 ppb in 1974). The Central and Eastern Basins of Lake Erie contained residues that fell about mid-way between these means. TDE was the predominant component of ΣDDT and was followed by DDE at approximately half this residue. While DDT represented the lowest component in lake sediments, it was the highest component in suspended solids from the Detroit River.HEOD was present in the entire lake system but at only a fraction of the level of ΣDDT. The mean residue in Lake St. Clair was only 0.1 ppb while Lake Erie sediments contained 1–2 ppb. The highest mean residue (3.6 ppb) was in suspended solids in the Detroit River. Other organochlorine insecticides were only occasionally identified.PCB residues in sediment were approximately 3 times higher than the total organochlorine insecticide residue, being highest in the Western Basin (252 ppb) and lowest in Lake St. Clair (19 ppb in 1970 and 10 ppb in 1974). The Detroit River and Central and Eastern Basins of Lake Erie had intermediate residues.Residues in Lake St. Clair indicated a decline in ΣDDT, HEOD, and PCB residues between 1970 and 1974, and this coincided with the restrictions on the materials. A core sample from the Western Basin of Lake Erie indicated that ΣDDT, HEOD and PCB began to accumulate in sediments in 1958, 1953, and 1956, respectively. This appeared to indicate a lag period of 2–5 years after wide-spread use occurred.     

Pollutants in harp seals (Phoca groenlandica). I. Organochlorines

Between 1976 and 1978, 248 harp seals were sampled from 5 locations in the Northwest Atlantic and Arctic for organochlorine (OC) residue analysis in tissue. Blood, kidney, brain, muscle and blubber samples were analysed for PCB, DDT, dieldrin, hexachlorobenzene (HCB), and heptachlor epoxide. Levels were generally greatest in blubber tissue. Overall, mean levels of DDT and PCB were greater than those of other OC. A barrier prevented OC compounds from accumulating in the brain to the level one might expect in lipid tissues. Positive correlations were found between 1: DDT and PCB, 2: DDT and dieldrin, and 3: PCB and deildrin.Male harp seals bioaccumulated DDT, PCB, heptachlor epoxide and dieldrin with age. As a group, adult males sampled in the Gulf of St. Lawrence carried the highest concentrations of all OC, except that chlordane did not appear to bioaccumulate and levels of hexachlorobenzene were minimal. Females generally ceased exhibiting significant bioaccumulation once breeding age was reached, due to transplacental and transmammary residue transfer of OC from mother to pup. There were some significant differences in OC levels between locations with DDT: Gulf > Front; PCB: Gulf > Front; dieldrin: Gulf > Front; heptachlor epoxide: Front > Gulf. No significant differences were found, however, when northern locations (Grise Fiord, Northwest Greenland, Pangnirtung) were compared to southern (Gulf, Front) on a group basis. The latter is not surprising in view of the harp seals extensive cyclical annual migration between the southern breeding grounds and the High Arctic.     

Image segmentation by a deformable contour model incorporating region analysis

Deformable contour models are useful tools for image segmentation. However, many fields depend mainly on local edge-based image features to guide the convergence of the contour. This makes the models sensitive to noise and the initial estimate. Our model incorporates region-based image features to improve its convergence and to reduce its dependence on initial estimation. Computational efficiency is achieved by an optimization strategy, modified from the greedy algorithm of Williams and Shah. The model allows a simultaneous optimization of multiple contours, making it useful for a large variety of segmentation problems.     

Cerebral processing of words and the development of chronic pain

Decreased glutamine availability is proposed as a mechanism for changes in immune function with intense exhaustive exercise. Less is known about the immunomodulatory effects of regular nonexhaustive exercise. To determine the effects of low intensity regular exercise and dietary glutamine supplementation on plasma glutamine concentrations, lymphocyte metabolism, and immune function, male (278 +/- 5 g) and female (182 +/- 1 g) Sprague-Dawley Buffalo rats were fed nutritionally complete casein-based semi-purified diets +/- 2% w/w glutamine. Rats were trained (21 d), as confirmed by higher (P < 0.05) succinate dehydrogenase activity in soleus muscle, to swim 2 or 4 h.d-1 or remained sedentary. Exercise lowered plasma concentrations of tryptophan, glutamate, methionine, alanine, threonine, aspartate, asparagine, and ornithine and increased the lysine concentration (P < 0.05). Neither diet nor exercise altered plasma glutamine concentrations, lymphocyte phenotypes in spleen, or the in vitro rates of splenocyte energy metabolism (production of glucose and glutamine metabolites or ATP concentrations in the incubation media). Compared with nonsupplemented rats, splenic cytolytic activity (lysis of 51Cr labeled YAC-1 cells) was reduced (P < 0.05) in the glutamine-supplemented exercising group. Under these conditions, glutamine supplementation does not appear to provide any added benefit to the exercise-trained animal.     

CNP overexpression induces aberrant oligodendrocyte membranes and inhibits MBP accumulation and myelin compaction

2',3'-Cyclic nucleotide 3'-phosphodiesterase (CNP) is highly enriched in myelin-forming cells where it is concentrated at the cytoplasmic side of all surface membranes except those of compact myelin. Previous studies have provided evidence that CNP is functionally involved in migration or expansion of membranes during myelination. This hypothesis is supported, in part, by the production of aberrant myelin membranes in transgenic mice that have a 6-fold increase in CNP expression. In addition, many myelin lamellae in these CNP-overexpressing mice lacked major dense lines (MDLs). The purpose of the present study was to determine if CNP overexpression altered: (1) oligodendrocyte and myelin membrane production during early stages of myelination, and (2) the ultrastructural distribution of CNP and myelin basic protein (MBP) in myelin membranes. We identified aberrant membrane expanses that extended from premyelinating oligodendrocyte processes, the periaxonal membrane, and the contact point between oligodendrocyte processes and myelin internodes. Myelin membranes without MDLs were deficient in MBP and enriched in CNP. These data support a functional role for CNP during oligodendrocyte membrane expansion and indicate, for the first time, that CNP may help target MBP to compact myelin.