Biomarkers in pediatrics: children as biomarker orphans

Biomarkers have enormous potential to improve patient care by establishing tests of diagnosis, prognosis, and treatment effects. Successfully translating a biomarker from discovery to clinical application demands high-quality discovery research and high-quality clinical studies for biomarker validation; however, there are additional challenges that face biomarker research in pediatrics. There are also additional characteristics of pediatric medicine that make biomarker research especially needed. This review focuses on the fundamentals of biomarkers, the additional considerations needed for applying biomarker research to children, and recommendations for advancing pediatric biomarker research.     

Space-time tradeoffs for linear recursion

A linear recursive procedure is one each of whose executions activates at most one invocation of itself. When linear recursion cannot be replaced by iteration, it is usually implemented with a stack of size proportional to the depth of recursion. In this paper we analyze implementations of linear recursion which permit large reductions in storage space at the expense of a small increase in computation time. For example, if the depth of recursion isn, storage space can be reduced to \(\sqrt n \) at the cost of a constant factor increase in running time. The problem is treated by abstracting any implementation of linear recursion as the pebbling of a simple graph, and for this abstraction we exhibit the optimal space-time tradeoffs.     

Odometry-Based Viterbi Localization with Artificial Neural Networks and Laser Range Finders for Mobile Robots

This paper proposes an approach that solves the Robot Localization problem by using a conditional state-transition Hidden Markov Model (HMM). Through the use of Self Organized Maps (SOMs) a Tolerant Observation Model (TOM) is built, while odometer-dependent transition probabilities are used for building an Odometer-Dependent Motion Model (ODMM). By using the Viterbi Algorithm and establishing a trigger value when evaluating the state-transition updates, the presented approach can easily take care of Position Tracking (PT), Global Localization (GL) and Robot Kidnapping (RK) with an ease of implementation difficult to achieve in most of the state-of-the-art localization algorithms. Also, an optimization is presented to allow the algorithm to run in standard microprocessors in real time, without the need of huge probability gridmaps.     

Location of nucleolar organizing regions on the chromosomes of the Syrian hamster (Mesocricetus auratus) and the Djungarian hamster (Phodopus sungorus)

Terminal chromosome associations ("satellite associations") in ASG-banded preparations have been used to determine the number and location of staellites in the Syrian hamster (Mesocricetus auratus) and the Djungarian hamster (Phodopus sungorus). Five pairs of satellites are found in the former and four in the latter. Nucleolar organizing regions (NORs) were visualized with the Ag-AS silver precipitation technique, and their number and position corresponded exactly with the number and position of satellites in Phodopus, where positive chromosome identification can be made in the absence of banding. Numerical agreement is exact in Mesocricetus as well, and the morphology of the silver-tagged NOR-bearing chromosomes strongly suggests that corrrespondence also occurs in this species.     

Hydrothermal catalytic production of fuels and chemicals from aquatic biomass

One of the promising avenues for biomass processing is the use of water as a reaction medium for wet or aquatic biomass. This review focuses on the hydrothermal catalytic production of fuels and chemicals from aquatic biomass. Two different regimes for conversion of aquatic biomass in hydrothermal conditions are discussed in detail. The first is hydrothermal liquefaction, and the second is hydrothermal gasification. The goals of these processes are to produce liquid‐fuel‐range hydrocarbons and methane or hydrogen, respectively. The catalytic upgrading of biocrude resulting from noncatalytic liquefaction and the stability and degradation of catalysts in high temperature water are also discussed. The review concludes with a brief discussion of the outlook for and opportunities within the field of hydrothermal catalytic valorization of biomass. Copyright © 2012 Society of Chemical Industry     

A systems theoretic approach to second moment modelling of probabilistic engineering systems∗

A new approach to modelling probabilistic and stochastic engineering systems using graph theory is outlined. This approach emphasizes the introduction of probabilistic and stochastic concepts at the very beginning of the model building process. This is in marked contrast to past tendencies to add probabilistic concepts to the end of an otherwise deterministic model building process. The development of topological models founded on oriented probabilistic measurements is given. which leads to the identification of some useful statistical properties of the’ random interconnection equations’. The development of probabilistic component models is given, where a component can be characterized independently of other components. Methods for automatically building the second moment representation of the Mixed Nodal Tableau are discussed. The application of the above theory to the probabilistic analysis of a pipe network problem is briefly described.     

Characterization of products from fast and isothermal hydrothermal liquefaction of microalgae

We investigated nonisothermal (fast) and nominally isothermal hydrothermal liquefaction (HTL) of Nannochloropsis sp. microalgae for the production of biocrude. Biocrude yields ranged from 36 to 45 wt % (dry weight), with fast HTL with low mass loading giving the highest yield. This condition also gave the biocrude with the lowest heating value, which indicates there are compromises to be made between biocrude quantity and quality. The aqueous phase and biocrude product fractions were characterized using elemental analysis and Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR MS). This detailed level of analysis identified more than 30,000 unique molecular products. The aqueous phase products included compounds with the same molecular formulae as known herbicides, which may inform efforts in genetic engineering of algae and/or bacteria for cultivation on the aqueous phase. This detailed molecular‐level characterization provides some clues regarding the types of reactions that may take place during HTL. © 2016 American Institute of Chemical Engineers AIChE J, 62: 815–828, 2016     

Terephthalic acid synthesis at higher concentrations in high‐temperature liquid water. 2. Eliminating undesired byproducts

We synthesized terephthalic acid (TPA) from p‐xylene at an initial concentration above its solubility limit in high‐temperature liquid water (HTW). The nominal p‐xylene loading at the reaction conditions was 0.4 mol L^?1, which is the highest reported to date for generation of high TPA yields (>70 mol %) in HTW. The presence of two liquid phases during the reaction did not appear to accelerate the rate, unlike behavior reported for some other organic reactions done “on water” at lower temperatures. Adding oxygen gas in a large increment during synthesis produced a black liquid and a black solid byproduct, which is a previously undocumented problem. Adding oxygen in smaller increments prevented formation of the liquid and solid byproducts and also provided high selectivities (90 mol %) and yields (>70 mol %) of TPA. These results demonstrate the feasibility of HTW as a medium for TPA synthesis at p‐xylene concentrations even higher than its solubility limit. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Parotid gland tissues investigated by picosecond time-gated andoptical spectroscopic imaging techniques

Near-infrared (NIR) time-resolved and spectroscopic transillumination imaging techniques are used to investigate normal tissues and Warthin's tumor of human parotid glands. The time-sliced imaging arrangement uses 120-fs, 1-kHz repetition-rate, 800-nm pulses from a Ti: sapphire laser and amplifier system for sample illumination and an ultrafast gated intensified camera system (UGICS) for recording two-dimensional (2-D) images using transmitted light. Images recorded with earlier temporal slices (approximately first 100 ps) of transmitted light highlight the tumor, while those recorded with later temporal slices (later than 200 ps) accentuate normal tissues. The spectroscopic imaging arrangement uses 1210-1300 nm tunable output of a Cr: forsterite laser for sample illumination, a Fourier space gate to discriminate against multiple-scattered light, and a NIR area camera to record 2-D images. The tumor region in the specimen appears brighter than the normal region in spectroscopic images recorded with light of different wavelengths. A wavelength-dependent variation in the ratio of light transmission through the tumor to that through the normal parotid gland is observed. Differences in scattering and wavelength-dependent absorption characteristics of normal parotid gland and Warthin's tumor provide a consistent explanation of these observed features. Histopathological analysis of the specimen sheds light on the probable origin of the differences in scattering and absorption characteristics     

SPIFI: a direct-detection imaging spectrometer for submillimeter wavelengths

The South Pole Imaging Fabry-Perot Interferometer (SPIFI) is the first instrument of its kind-a direct-detection imaging spectrometer for astronomy in the submillimeter band. SPIFI's focal plane is a square array of 25 silicon bolometers cooled to 60 mK; the spectrometer consists of two cryogenic scanning Fabry-Perot interferometers in series with a 60-mK bandpass filter. The instrument operates in the short submillimeter windows (350 and 450 microm) available from the ground, with spectral resolving power selectable between 500 and 10,000. At present, SPIFI's sensitivity is within a factor of 1.5-3 of the photon background limit, comparable with the best heterodyne spectrometers. The instrument's large bandwidth and mapping capability provide substantial advantages for specific astrophysical projects, including deep extragalactic observations. We present the motivation for and design of SPIFI and its operational characteristics on the telescope.