Parallel Deterministic and Stochastic Global Minimization of Functions with Very Many Minima

The optimization of three problems with high dimensionality and many local minima are investigated under five different optimization algorithms: DIRECT, simulated annealing, Spall’s SPSA algorithm, the KNITRO package, and QNSTOP, a new algorithm developed at Indiana University

Emerging applications of integrated optical microcombs for analogue RF and microwave photonic signal processing

We review new applications of integrated microcombs in RF and microwave photonic systems. We demonstrate a wide range of powerful functions including a photonic intensity high order and fractional differentiators, optical true time delays, advanced filters, RF channelizer and other functions, based on a Kerr optical comb generated by a compact integrated microring resonator, or microcomb. The microcomb is CMOS compatible and contains a large number of comb lines, which can serve as a high performance multiwavelength source for the transversal filter, thus greatly reduce the cost, size, and complexity of the system. The operation principle of these functions is theoretically analyzed, and experimental demonstrations are presented.Comment: 16 pages, 8 figures, 136 References. Photonics West 2018 invited paper, expanded version. arXiv admin note: substantial text overlap with arXiv:1710.00678, arXiv:1710.0861

Strain-dependent variation in the early transcriptional response to CNS injury using a cortical explant system

<p>Abstract</p> <p>Background</p> <p>While it is clear that inbred strains of mice have variations in immunological responsiveness, the influence of genetic background following tissue damage in the central nervous system is not fully understood. A cortical explant system was employed as a model for injury to determine whether the immediate transcriptional response to tissue resection revealed differences among three mouse strains.</p> <p>Methods</p> <p>Immunological mRNAs were measured in cerebral cortex from SJL/J, C57BL/6J, and BALB/cJ mice using real time RT-PCR. Freshly isolated cortical tissue and cortical sections incubated in explant medium were examined. Levels of mRNA, normalized to β-actin, were compared using one way analysis of variance with pooled samples from each mouse strain.</p> <p>Results</p> <p>In freshly isolated cerebral cortex, transcript levels of many pro-inflammatory mediators were not significantly different among the strains or too low for comparison. Constitutive, baseline amounts of CD74 and antisecretory factor (ASF) mRNAs, however, were higher in SJL/J and C57BL/6J, respectively. When sections of cortical tissue were incubated in explant medium, increased message for a number of pro-inflammatory cytokines and chemokines occurred within five hours. Message for chemokines, IL-1α, and COX-2 transcripts were higher in C57BL/6J cortical explants relative to SJL/J and BALB/cJ. IL-1β, IL-12/23 p40, and TNF-α were lower in BALB/cJ explants relative to SJL/J and C57BL/6J. Similar to observations in freshly isolated cortex, CD74 mRNA remained higher in SJL/J explants. The ASF mRNA in SJL/J explants, however, was now lower than levels in both C57BL/6J and BALB/cJ explants.</p> <p>Conclusions</p> <p>The short-term cortical explant model employed in this study provides a basic approach to evaluate an early transcriptional response to neurological damage, and can identify expression differences in genes that are influenced by genetic background.</p

Progressive changes in microglia and macrophages in spinal cord and peripheral nerve in the transgenic rat model of amyotrophic lateral sclerosis

<p>Abstract</p> <p>Background</p> <p>The role of neuroinflammation in motor neuron death of amyotrophic lateral sclerosis (ALS) is unclear. The human mutant superoxide dismutase-1 (hmSOD1)-expressing murine transgenic model of ALS has provided some insight into changes in microglia activity during disease progression. The purpose of this study was to gain further knowledge by characterizing the immunological changes during disease progression in the spinal cord and peripheral nerve using the more recently developed hmSOD1 rat transgenic model of ALS.</p> <p>Methods</p> <p>Using immunohistochemistry, the extent and intensity of tissue CD11b expression in spinal cord, lumbar nerve roots, and sciatic nerve were evaluated in hmSOD1 rats that were pre-clinical, at clinical onset, and near disease end-stage. Changes in CD11b expression were compared to the detection of MHC class II and CD68 microglial activation markers in the ventral horn of the spinal cord, as well as to the changes in astrocytic GFAP expression.</p> <p>Results</p> <p>Our study reveals an accumulation of microglia/macrophages both in the spinal cord and peripheral nerve prior to clinical onset based on CD11b tissue expression. The microglia formed focal aggregates in the ventral horn and became more widespread as the disease progressed. Hypertrophic astrocytes were not prominent in the ventral horn until after clinical onset, and the enhancement of GFAP did not have a strong correlation to increased CD11b expression. Detection of MHC class II and CD68 expression was found in the ventral horn only after clinical onset. The macrophages in the ventral nerve root and sciatic nerve of hmSOD1 rats were observed encircling axons.</p> <p>Conclusions</p> <p>These findings describe for the first time in the hmSOD1 rat transgenic model of ALS that enhancement of microglia/macrophage activity occurs pre-clinically both in the peripheral nerve and in the spinal cord. CD11b expression is shown to be a superior indicator for early immunological changes compared to other microglia activation markers and astrogliosis. Furthermore, we suggest that the early activity of microglia/macrophages is involved in the early phase of motor neuron degeneration and propose that studies involving immunomodulation in hmSOD1transgenic models need to consider effects on macrophages in peripheral nerves as well as to microglia in the spinal cord.</p

Australia’s first trap-and-haul fishway: Nerang River, Queensland

Australia’s first trap-and-haul fishway was built on the Nerang River in southeast Queensland during enlargement of the Hinze Dam. In gaining government approval for the project, the constructing alliance (HDA) concluded that providing upstream fish passage would have significant environmental benefits by conserving upstream native fish communities and encouraging recruitment into the reservoir’s recreational fishery. But downstream passage, other than modifications to protect fish emigrating during spill events, could not be justified. Severely constrained outflows from the dam and the impacts of downstream urban development contrast starkly with upstream habitat conditions. North American design approaches were adapted to suit the river’s fishes and streamflows. Challenges for fish passage at the site included the marked restriction of downstream river flows and the location of the flow-release point 300m from the spillway. A barrier weir was built to prevent upstream migrants bypassing the fishway entrance during spillway flows. HDA developed a trap-and-haul system to collect migrating fish at the weir and transport them by tanker to multiple upstream release areas. This system provides flexibility to accommodate varying fish biomass; ability to operate over a range of flows up to 20-year ARI events; facilities for sorting, data collection and removal of pest species; and capacity to limit predation mortalities. Fishway performance studies led to redesign of the entrance vee-trap and other modifications. To 2017, 55,590 fish from 27 large and small-bodied species used the fishway, together with 8 turtles. Fish of three pest species were identified in the sorting facility and removed to prevent their entry to the reservoir. This paper covers the project life cycle for Australia’s first trap-and-haul fishway including the basis for selecting the fishway type, design and construction. Fishway performance studies and results from ongoing operation, including the lessons learned and the improvements made, are also discussed

Photonic RF and microwave reconfigurable filters and true time delays based on an integrated optical Kerr frequency comb source

We demonstrate advanced transversal radio frequency (RF) and microwave functions based on a Kerr optical comb source generated by an integrated micro-ring resonator. We achieve extremely high performance for an optical true time delay aimed at tunable phased array antenna applications, as well as reconfigurable microwave photonic filters. Our results agree well with theory. We show that our true time delay would yield a phased array antenna with features that include high angular resolution and a wide range of beam steering angles, while the microwave photonic filters feature high Q factors, wideband tunability, and highly reconfigurable filtering shapes. These results show that our approach is a competitive solution to implementing reconfigurable, high performance and potentially low cost RF and microwaveComment: 15 pages, 11 Figures, 60 Reference