Carotenoids production from a newly isolated <Emphasis Type="Italic">Sporidiobolus pararoseus</Emphasis> strain by submerged fermentation

This work aimed at evaluating the total carotenoids production by a newly isolated Sporidiobolus pararoseus. Bioproduction was carried out in an orbital shaker, using 10% (w/v) of inoculum (25 °C, 180 rpm for 35 h), incubated for 120 h in a dark room. Liquid N₂ and dimethylsulphoxide (DMSO) were used for cell rupture, and carotenoids were extracted with a solution of acetone/methanol (7:3, v/v). Optimization of carotenoids bioproduction was achieved by experimental design technique. Initially, a Plackett–Burman design was used for the screening of the most important factors, after the statistical analysis, a complete second-order design was carried out to optimize the concentration of total carotenoids in a conventional medium. Maximum concentration of 856 μg/L of total carotenoids was obtained in a medium containing 60 g/L of glucose, 15 g/L of peptone, and 15 g/L of malt extract, 25 °C, initial pH 4.0 and 180 rpm. Fermentation kinetics showed that the maximum concentration of total carotenoids was reached after 102 h of fermentation and that carotenoids bioproduction was associated with cell growth.     

Prediction of fertility by centrifugal countercurrent distribution (CCCD) analysis: correlation between viability and heterogeneity of ram semen and field fertility

The prediction of the fertilizing ability of a sire or a given insemination dose is a primary aim in the field of artificial insemination. Centrifugal countercurrent distribution analysis (CCCD) was used to determine the relationship between some sperm parameters and the in vivo fertility rate obtained with the same sample after cervical artificial insemination. A total of 522 ewes from 26 different farms was inseminated with 53 ejaculates obtained from 25 mature Rasa aragonesa rams. Semen was diluted to 1.6 x 10(9) cells ml-1 and doses of 0.25 ml were prepared and kept at 15 degrees C until used for insemination. The same ejaculates were used for analysis of standard semen parameters and CCCD analysis. Sperm motility, concentration and viability were determined before and after CCCD. Post-CCCD parameters were derived from the analysis of the profile obtained after CCCD. The recovered viability showed the highest correlation with fertility, especially in the central chambers (V2), r = 0.415, P < 0.005). The ejaculate heterogeneity also showed a positive correlation with field fertility (r = 0.23), with a tendency towards significance (P < 0.1). The mean fertility value of all ejaculates used in this study was 46.75%, ranging from 12.5% to 75.0%. Ejaculates were classified into two categories according to their fertility: higher and lower than the mean value. Only the viability recovered in the central chambers (V2) was a parameter with a predictive capacity to discriminate between the two groups (P < 0.05). A predictive equation for field fertility with a correlation coefficient r = 0.488 and a very high level of significance (P < 0.005) was deduced by multiple analysis: PF = 6.02 + 0.069V2 + 0.315H (where PF is predictive fertility, V2 is the recovered viability in the CCCD profile central chambers and H is heterogeneity).     

Explicit formulas of normalized radiation modes in multilayerwaveguides

A new formulation for the normalization of radiation modes in one-dimensional lossless multilayer waveguide structures is derived using the transmission matrix method. In this formulation, an individual radiation mode is excited by two sources located at opposite ends of the two outermost regions of the waveguide. Proper choice of the absolute phase of one of the sources results in simple expressions for the normalized radiation modes. Calculation of radiation loss of grating-assisted directional couplers is used as an example to show the simplicity and usefulness of this method     

Error measures for scene segmentation

Scene segmentation is an important problem in pattern recognition. Current subjective methods for evaluation and comparison of scene segmentation techniques are inadequate and objective quantitative measures are desirable. Two error measures, the percentage area misclassified (p) and a new pixel distance error (ε) were defined and evaluated in terms of their correlation with human observation for comparison of multiple segmentations of the same scene and multiple scenes segmented by the same technique. The results indicate that both these measures can be helpful in the evaluation and comparison of scene segmentation procedures.     

Design of integrated data/voice stations for a CSMA/CD LAN

This paper describes the design and implementation of integrated data/voice stations for a LAN environment. The stations are based on the DB16000 Development Board using a 16-bit CPU. Continuously variable slope delta modulation is selected as the voice encoding technique. Protocols were designed and implemented to handle data and voice separately. Prototypes were built to test the station's performance. The stations communicate with one another at a rate of 1.5 Mbit/s. The voice digitization rate is 16 kbit/s and the terminal speed is 9.6 kbit/s.     

Ageing properties of polyurethane methacrylate and off‐stoichiometry thiol‐ene polymers after nitrogen and argon plasma treatment

Proprietary mixture of polyurethane methacrylate (PUMA) and off‐stoichiometry thiol‐ene (OSTE‐80) are evaluated as two possible polymeric substrates to prototype microfluidic biochips. Because of their lack of biocompatibility, PUMA and OSTE‐80 are modified by argon (Ar) or nitrogen (N₂) plasma treatment to introduce nitrogen moieties that are highly polar and conducive for cell attachment and growth. XPS and water contact angle measurement show that these nitrogen groups are relatively stable in the plasma‐treated PUMA and OSTE‐80 in spite of the hydrophobic recovery and volatilization of nitrogen moieties during air ageing for 15 days. This stability can be attributed to their high degree crosslinking that is reflected by the increase of elastic modulus of PUMA and OSTE‐80 during their air ageing. These results show that Ar and N₂ plasma‐treated PUMA and OSTE‐80 possess the necessary physical and chemical properties to be evaluated further to develop microfluidic biochips for biological applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44107.     

Tissue Mimicry in Morphology and Composition Promotes Hierarchical Matrix Remodeling of Invading Stem Cells in Osteochondral and Meniscus Scaffolds

An integral approach toward in situ tissue engineering through scaffolds that mimic tissue with regard to both tissue architecture and biochemical composition is presented. Monolithic osteochondral and meniscus scaffolds are prepared with tissue analog layered biochemical composition and perpendicularly oriented continuous micropores by a newly developed cryostructuring technology. These scaffolds enable rapid cell ingrowth and induce zonal‐specific matrix synthesis of human multipotent mesenchymal stromal cells solely through their design without the need for supplementation of soluble factors such as growth factors.     

A multivariate-logistic model for acceptance of indoor environmental quality (IEQ) in offices

The indoor environmental quality (IEQ) in offices is examined from the prospect of an occupant's acceptance in four aspects: thermal comfort, indoor air quality, noise level and illumination level. Based on the evaluations made by 293 occupants of the IEQ of offices in Hong Kong, empirical expressions have been proposed to approximate an overall IEQ acceptance of an office environment at certain operative temperature (T_o), carbon dioxide concentration (CO₂), equivalent noise level (L_eq) and illumination level (lux). The overall IEQ acceptance is calculated from a multivariate logistic regression model. A range of acceptance in typical office environmental conditions and its dependence on the four parameters stated above are determined for design conditions. The proposed overall IEQ acceptance can be used as a quantitative assessment criterion for an office environment and similar environment where an occupant's evaluation is expected.     

Risks of unsatisfactory airborne bacteria level in air-conditioned offices of subtropical climates

Adjustment of the indoor air temperature and relative humidity set points for energy conservation is adopted in many air-conditioned offices in the subtropics. This study examines the environmental risks in an air-conditioned office with a ‘readjusted’ thermal environment from the perspective of the probable airborne bacteria level exceeding certain limits. In particular, a cross-sectional study of bacteria concentrations in 422 air-conditioned offices in Hong Kong was conducted, and a mathematical expression was proposed to correlate the indoor bacteria level with the indoor air temperature and relative humidity in an air-conditioned office. With the proposed correlation, the probability of an air-conditioned office having an unsatisfactory airborne bacteria level could be determined. The model results were verified with the measurement results from some other studies. This model would be a useful tool for preliminary assessment of the environmental risks, regarding the airborne bacteria level while balancing some energy conservation measures, in an air-conditioned office in the subtropics. The study also provides a template for developing an environmental risk assessment model in air-conditioned spaces elsewhere.