Neural ensemble coding of target identity in echolocating bats

The Volvo plant at Olofstr?m, Sweden is engaged in the pressing and assembling of sheet-metal components for automobiles. During the past 25 years, determined efforts have been made to introduce less noisy methods of production and to limit the levels of noise emission in three large workshops at the plant. Noise levels were mapped with the aid of stationary noise measurements. The results are expressed in terms of noise emission zones and presented as noise contour maps. The investigations were made on four occasions between 1967 and 1991. Following the comparative area calculations of the noise emission zones, it was deduced that the noise levels had been significantly reduced, despite an increased production. The results show that noise reduction measures applied to the presses. An increase in automation in sheet-metal handling, improved quality in the pressing of components and changes in the range of products have contributed to the reduction of noise levels at the plant.     

Proximity-effect bridges with external controllable electrical characteristics

We report the experimental characteristics of long superconducting proximity-effect bridges in which the proximity-effect induced weak overlay region is further weakened by creating a nonequilibrium excess quasiparticle population. Nonequilibrium quasiparticles are generated in the overlay region by pairbreaking, by thermal nonequilibrium phonons dc injected from the transverse normal metal strip. The results show that the critical current of these bridges can be electrically controlled at any temperature below the superconducting transition temperature.     

Effect of Mo on the High-Temperature Creep Resistance and Machinability of a Recycled Al-Alloy with High Iron Impurity

Journal of Materials Engineering and Performance - Reported work focuses on the effect of morphology of the Fe-rich intermetallic phases on the machinability of Al-alloy containing >2wt.%...     

Electron Beam Irradiation to Recrosslink Devulcanized Sulfur Cured Rubber Blended Polypropylene

This study aims to investigate the effect electron beam (EB) irradiation on the polypropylene/devulcanized sulfur cured rubber (PP‐DVC) compound. The PP‐DVC compounds were compounded using twin‐screw extruder and then compression molded into required shapes before irradiation begins. The gel content of all irradiated PP‐DVC compounds gradually increased with higher irradiation dose indicated that the presence of DVC plays an important role in crosslinking enhancement. The mechanical properties of PP‐DVC compounds were observed marginally higher at low irradiation dosages (≤50 kGy). However, higher irradiation dosages up to 200 kGy cause adverse effect to the PP‐DVC compounds. In addition, the application of low irradiation dosage could enhance the dispersion of DVC particles at 20 phr composition in PP matrix. This also found that the scanning electron microscopy (SEM) observation where the DVC particles dispersed better in PP matrix compared to that of nonirradiated samples. Further increment in irradiation dosages up to 200 kGy reduced the crystallinity caused by chain scissoring process could rupture the crystalline structure in PP matrix. It was also found that the wavenumber of the C? H and CH₂ groups for irradiated samples reduced at high irradiation dosages due to the formation of carbonyl group. POLYM. ENG. SCI., 59:1017–1027, 2019. © 2019 Society of Plastics Engineers     

Failures analysis of particle reinforced metal matrix composites by microstructure based models

This paper discusses the methodology of microstructure based elastic–plastic finite element analysis of particle reinforced metal matrix composites. This model is used to predict the failure of two dimensional microstructure models under tensile loading conditions. A literature survey indicates that the major failure mechanism of particle reinforced metal matrix composites such as particle fracture, interfaces decohesion and matrix yielding is mainly dominated by the distribution of particles in the matrix. Hence, analyses were carried out on the microstructure of random and clustered particles to determine its effect on strength and failure mechanisms. The finite element analysis models were generated in ANSYS, using scanning electron microscope images. The percentage of major failures and stress–strain responses were predicted numerically for each microstructure. It is evident from the analysis that the clustering nature of particles in the matrix dominates the failure modes of particle reinforced metal matrix composites.     

Influence of Processing Temperatures on Mechanical Properties and Microstructure of Squeeze Cast Aluminum Alloy Composites

The paper deals with the influence of melt and die temperatures on the squeeze cast silicon carbide particulate reinforced aluminum alloy composites. Samples were produced at the following constant melt and die temperatures: melt—750, 800, 850, and 900°C; die—250, 300, 350, and 400°C. During the specimen fabrication, pressure was maintained at 100 MPa. The results reveal significant influence of both melt and die temperatures on the mechanical properties. The optimum melt and die temperatures for the preparation of the composite are 850°C and 350 °C, respectively. Tensile and impact strengths, and hardness of composite samples prepared at this temperature combination are found to be better than those of samples prepared at other temperatures. Additionally, microstructures of samples prepared at this temperature combination display a relatively fine grain structure and the smallest degree of particle agglomeration which explain the dependence of mechanical properties on the melt and die temperatures.     

Intramuscular injection as a provoking factor for paralysis in acute poliomyelitis. A case control study

In order to identify the role of intramuscular injection (IM) as a provoking factor for poliomyelitis, a case control study as done at the Institute of Child Health, Madras from May 1988 to May 1989. The case was defined as acute poliomyelitis if he had acute asymmetric flaccid paralysis of lower motor neurone type without objective sensory disturbance following a short episode of fever. Controls were taken from children attending outpatient department for fever. Two controls matched for aged and sex were recruited for each case. Recruitment, data collection and clinical examination were done by a single pediatrician. IM injection received within 30 days prior to onset of paralysis or illness was considered to be the risk factor. The total number of cases and controls recruited were 257 and 515, respectively. Among cases, 172 (66.9%) out of 257 and among controls 252 (48.9%) out of 515, received IM injection within one month earlier to onset of paralysis or illness. The overall risk of paralysis, estimated for IM injection, was increased [odds ratio (OR) 2.1 (95% CI, 1.5-3.0)]. The maximum risk for paralysis was observed to be 2 weeks preceding the illness; the ORs for < 7 days was 2.2 (95% CI, 1.6-3.2) and for 7-13 days 3.2 (95% CI, 1.8 to 5.8). The risk of paralysis associated with IM injection was similar for unimmunized and immunized cases (OR 2.4 and 2.2). Multiple injections were not associated with a higher risk of developing paralysis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Decreased levels of amniotic fluid oxytocinase activity in preeclampsia

Oxytocinase (EC 3.4.11.3) activity was determined in 80 amniotic fluid samples obtained from 40 normotensive primigravidas (median age 27 years) and 40 primigravidas (median age 29 years) with pregnancies complicated by preeclampsia between 32 and 39 weeks of gestation. The enzyme activity was significantly lower in preeclampsia than in normal pregnancy with matched gestations (p < 0.01). Considering the possible involvement of vasopressin and angiotensin II in preeclampsia, it is suggested that the enzyme which degrades these pressor hormones may play a role in the pathogenesis of hypertensive pregnancy.     

A flexible optical switch architecture for efficient transmission of optical bursts

In this paper, we propose a new optical switch architecture for optical WDM networks. Flexibility and efficiency in terms of controlling and utilizing optical power are key features of the architecture. The architecture uses switching components which have increased flexibility of how optical power received on an input port is managed when switching optical signals. Like the traditional optical switches, optical power can be directed towards one output port only. Further, unlike the traditional switches, on need basis, the power can be split on a desired sub-set of output ports, thus reducing power wastage on unwanted ports. Such split power can be directed fully towards a single output port as and when it is needed. This flexible and efficient power management makes the architecture a potential candidate for optical networks with its usage in several dimensions. The dimensions include (1) switching methods such as circuit level switching and bursty level switching, (2) network types such as core, metro, and access networks, (3) support for technologies such as Light-trails and Light-trees, and (4) support for functionalities such as survivability and multicasting with new features. Importantly, there is potential that the architecture enhances adaptability based on the needs, and it supports co-existence and seamless integration of different environments.In this paper, our focus is on investigating bursty level switching using the proposed switch architecture. We use the flexibility of the switch and adopt a new switching method for data bursts. This switching method is efficient for switching bursts while introducing new challenges. Unlike the traditional switching method, it switches bursts arriving on an input link with zero (or very small) time gaps to different output links in certain scenarios. Further, it also switches bursts from different input links to the same output link when they arrive with zero (or very small) time interval. Adopting such switching approaches has potential benefits in terms of delay-load performance and blocking performance. While the bursts are switched from the same input link to different output links in this approach, it creates some unwanted signals. We investigate scenarios in which the unwanted signals create any problems and this poses some challenges. To address such challenges, we develop a transmission protocol. We investigate the performance of our solutions using simulation studies and verify the two significant gains: (1) networks’ capability to sustain traffic loads up to the maximum level in terms of the delay-load performance, which is similar to the performance seen for hypothetical ideal switches with zero switching time, and (2) improved blocking performance.     

Proteolysis of the carboxyl-terminal GPI signal independent of GPI modification as a mechanism for selective protein secretion

Variable amounts of soluble forms of a variety of glycosyl-phosphatidylinositol (GPI)-anchored proteins occur extracellularly, but the molecular mechanisms governing their release are not entirely clear. When the GPI-anchored folate receptor (FR) type beta was expressed transiently in human 293 fibroblasts, there was a roughly equal distribution of [3H]folic acid binding protein between the cell surface and the medium after 24 h over a wide range of expression levels of FR-beta. The difference in apparent molecular masses between the soluble FR-beta and the PI-PLC-treated membrane protein indicated that the former was not released from the membrane by the action of phospholipase. Brefeldin A inhibited the release of soluble FR-beta from both the transfected 293 cells and stable recombinant CHO (CHO-FR-beta) cells while pre-existing levels of cell surface FR were unaltered suggesting the absence of a precursor-product relationship between the membrane-associated FR-beta and the soluble protein in the medium. [35S]Cysteine pulse-chase analysis was consistent with this finding. Interchanging of carboxyl-terminal peptides between FR-beta and FR-alpha revealed that the nature of the processed signal for GPI modification was responsible for the quantitative membrane anchoring of FR-alpha and the production of soluble FR-beta. When total cell lysates were analyzed by Western blot, a diffuse band of apparent 41 kDa and three additional sharp bands of apparent 35, 33, and 29.3 kDa were seen. The 41 kDa band was identified as the PI-PLC sensitive cell surface receptor. Several mutant constructs of FR-beta, in which the carboxyl-terminal signal for GPI modification was either disrupted or deleted only gave the three lower bands. The three sharp bands from the wild-type and the mutant forms of FR-beta were identified as nonglycosylated (29.3 kDa) or glycosylated polypeptides in which the carboxyl-terminal peptide was at least partially proteolyzed without GPI modification. All of the mutations in the GPI signal resulted in the recovery of [3H]folic acid binding protein in the media which, similar to the wild-type FR recovered from the media, were converted to the 29.3 kDa band by N-glycanase. The results from this study indicate that a carboxyl-terminal peptide in FR-beta is efficiently proteolyzed intracellularly by a pathway that is independent of GPI signal recognition resulting in proper protein folding and secretion. Such carboxyl-terminal sequences could represent a simple adaptation for proteins whose physiologic functions reside both at the cell surface and in extracellular fluids, allowing their selective and tissue-specific release.