On the stability of high-speed milling with spindle speed variation

Spindle speed variation is a well-known technique to suppress regenerative machine tool vibrations, but it is usually considered to be effective only for low spindle speeds. In this paper, the effect of spindle speed variation is analyzed in the high-speed domain for spindle speeds corresponding to the first flip (period doubling) and to the first Hopf lobes. The optimal amplitudes and frequencies of the speed modulations are computed using the semidiscre- tization method. It is shown that period doubling chatter can effectively be suppressed by spindle speed variation, although, the technique is not effective for the quasiperiodic chatter above the Hopf lobe. The results are verified by cutting tests. Some special cases are also discussed where the practical behavior of the system differs from the predicted one in some ways. For these cases, it is pointed out that the concept of stability is understood on the scale of the principal period of the system—that is, the speed modulation period for variable spindle speed machining and the tooth passing period for constant spindle speed machining

Effect of Ultrasonic-Assisted Blanching on Size Variation, Heat Transfer, and Quality Parameters of Mushrooms

The main aim of this work was to assess the influence of the application of power ultrasound during blanching of mushrooms (60 90 °C) on the shrinkage, heat transfer, and quality parameters. Kinetics of mushroom shrinkage was modeled and coupled to a heat transfer model for conventional (CB) and ultrasonic-assisted blanching (UB). Cooking value and the integrated residual enzymatic activity were obtained through predicted temperatures and related to the hardness and color variations of mushrooms, respectively. The application of ultrasound led to an increase of shrinkage and heat transfer rates, being this increase more intense at low process temperatures. Consequently, processing time was decreased (30.7 46.0 %) and a reduction in hardness (25.2 40.8 %) and lightness (13.8 16.8 %) losses were obtained. The best retention of hardness was obtained by the UB at 60 °C, while to maintain the lightness it was the CB and UB at 90 °C. For enhancing both quality parameters simultaneously, a combined treatment (CT), which consisted of a CB 0.5 min at 90 °C and then an UB 19.9min at 60 °C, was designed. In this manner, compared with the conventional treatment at 60 °C, reductions of 39.1, 27.2, and 65.5 % for the process time, hardness and lightness losses were achieved, respectively. These results suggest that the CT could be considered as an interesting alternative to CB in order to reduce the processing time and improve the overall quality of blanched mushrooms.The authors acknowledge the financial support of Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional de La Plata from Argentina, Erasmus Mundus Action 2-Strand 1 and EuroTango II Researcher Training Program and Ministerio de Economia y Competitividad (SPAIN) and the FEDER (project DPI2012-37466-CO3-03).Lespinard, A.; Bon Corbín, J.; Cárcel Carrión, JA.; Benedito Fort, JJ.; Mascheroni, RH. (2015). Effect of Ultrasonic-Assisted Blanching on Size Variation, Heat Transfer, and Quality Parameters of Mushrooms. Food and Bioprocess Technology. 8(1):41-53. https://doi.org/10.1007/s11947-014-1373-zS415381Aguirre, L., Frias, J. M., Barry-Ryan, C., & Grogan, H. (2009). Modelling browning and brown spotting of mushrooms (Agaricus bisporus) stored in controlled environmental conditions using image analysis. Journal of Food Engineering, 91, 280–286.Anantheswaran, R. C., Sastry, S. K., Beelman, R. B., Okereke, A., & Konanayakam, M. (1986). Effect of processing on yield, color, and texture of canned mushrooms. Journal of Food Science, 51(5), 1197–1200.Biekman, E. S. A., Kroese-Hoedeman, H. I., & Schijvens, E. P. H. M. (1996). Loss of solutes during blanching of mushrooms (Agaricus bisporus) as a result of shrinkage and extraction. Journal of Food Engineering, 28(2), 139–152.Biekman, E. S. A., van Remmen, H. H. J., Kroese-Hoedeman, H. I., Ogink, J. J. M., & Schijvens, E. P. H. M. (1997). Effect of shrinkage on the temperature increase in evacuated mushrooms (Agaricus bisporus) during blanching. Journal of Food Engineering, 33(1–2), 87–99.Brennan, M., Le Port, G., & Gormley, R. (2000). Post-harvest treatment with citric acid or hydrogen peroxide to extend the shelf life of fresh sliced mushrooms. Lebensmittel Wissenschaft und Technologie, 33, 285–289.Cárcel, J. A., Benedito, J., Rosselló, C., & Mulet, A. (2007). Influence of ultrasound intensity on mass transfer in apple immersed in a sucrose solution. Journal of Food Engineering, 78, 472–479.Cárcel, J. A., Benedito, J., Bon, J., & Mulet, A. (2007). High intensity ultrasound effects on meat brining. Meat Science, 76, 611–619.Cárcel, J. A., García-Pérez, J. V., Benedito, J., & Mulet, A. (2011). Food process innovation through new technologies: Use of ultrasound. Journal of Food Engineering, 110, 200–207.Cheng, X., Zhang, M., & Adhikari, B. (2013). The inactivation kinetics of polyphenol oxidase in mushroom (Agaricus bisporus) during thermal and thermosonic treatmemts. Ultrasonics Sonochemistry, 20, 674–679.Cliffe-Byrnes, V., & O’Beirne, D. (2007). Effects of gas atmosphere and temperature on the respiration rates of whole and sliced mushrooms (Agaricus bisporus): implications for film permeability in modified atmosphere packages. Journal of Food Science, 72, 197–204.Coskuner, Y., & Ozdemir, Y. (1997). Effects of canning processes on the elements content of cultivated mushrooms (Agaricus bisporus). Food Chemistry, 60(4), 559–562.Cruz, R. M. S., Vieira, M. C., Fonseca, S. C., & Silva, C. L. M. (2011). Impact of thermal blanching and thermosonication treatments on watercress (Nasturtium officinale) quality: thermosonication process optimisation and microstructure evaluation. Food and Bioprocess Technology, 4(7), 1197–1204.De Gennaro, L., Cavella, S., Romano, R., & Masi, P. (1999). The use of ultrasound in food technology I: inactivation of peroxidase by thermosonication. Journal of Food Engineering, 39, 401–407.De la Fuente, S., Riera, E., Acosta, V. M., Blanco, A., & Gallego-Juárez, J. A. (2006). Food drying process by power ultrasound. Ultrasonics, 44, 523–527.Delgado, A. E., Zheng, L., & Sun, D. W. (2009). Influence of ultrasound on freezing rate of immersion-frozen apples. Food and Bioprocess Technology, 2, 263–270.Devece, C., Rodríguez-López, J. N., Fenoll, J. T., Catalá, J. M., De los Reyes, E., & García-Cánovas, F. (1999). Enzyme inactivation analysis for industrial blanching applications: comparison of microwave, conventional, and combination heat treatments on mushroom polyphenoloxidase activity. Journal of Agricultural and Food Chemistry, 47(11), 4506–4511.Fernandes, F. A. N., & Rodrigues, S. (2007). Ultrasound as pre-treatment for drying of fruits: dehydration of banana. Journal of Food Engineering, 82, 261–267.Gabaldón-Leyva, C. A., Quintero-Ramos, A., Barnard, J., Balandrán-Quintana, R. R., Talamás-Abbud, R., & Jiménez-Castro, J. (2007). Effect of ultrasound on the mass transfer and physical changes in brine bell pepper at different temperatures. Journal of Food Engineering, 81, 374–379.Gallego-Juárez, J. A., Riera, E., De la Fuente, S., Rodríguez-Corral, G., Acosta-Aparicio, V. M., & Blanco, A. (2007). Application of high-power ultrasound for dehydration of vegetables: processes and devices. Drying Technology, 25, 1893–1901.Gamboa-Santos, J., Montilla, A., Soria, A. C., & Villamiel, M. (2012). Effects of conventional and ultrasound blanching on enzyme inactivation and carbohydrate content of carrots. European Food Research and Technology, 234, 1071–1079.García-Pérez, J. V., Cárcel, J. A., De la Fuente, S., & Riera, E. (2006). Ultrasonic drying of foodstuff in a fluidized bed. Parametric study. Ultrasonics, 44, 539–543.García-Pérez, J. V., Cárcel, J. A., Riera, E., Rosselló, C., & Mulet, A. (2012). Intensification of low-temperature drying by using ultrasound. Drying Technology, 30, 1199–1208.Gonzáles-Fandos, E., Giménez, M., Olarte, C., Sanz, S., & Simón, A. (2000). Effect of packaging conditions on the growth of microorganisms and the quality characteristics of fresh mushrooms (Agaricus bisporus) stored at inadequate temperatures. Journal of Applied Microbiology, 89, 624–632.Gormley, T. R. (1975). Chill storage of mushrooms. Journal of the Science of Food and Agriculture, 26, 401–411.Gouzi, H., Depagne, C., & Coradin, T. (2012). Kinetics and thermodynamics of thermal inactivation of polyfenol oxidase in an aqueous extract from Agaricus bisporus. Journal of Agricultural and Food Chemistry, 60, 500–506.Holdsworth, S. D. (1997). Thermal processing of packaged foods. London: Chapman Hall.Horžić, D., Jambrak, A. R., Belščak-Cvitanović, A., Komes, D., & Lelas, V. (2012). Comparison of conventional and ultrasound assisted extraction techniques of yellow tea and bioactive composition of obtained extracts. Food and Bioprocess Technology, 5, 2858–2870.Jambrak, A. R., Mason, T. J., Paniwnyk, L., & Lelas, V. (2007a). Ultrasonic effect on pH, electric conductivity, and tissue surface of button mushrooms, brussels sprouts and cauliflower. Czech Journal of Food Science, 25, 90–99.Jambrak, A. R., Mason, T. J., Paniwnyk, L., & Lelas, V. (2007b). Accelerated drying of button mushrooms, Brussels sprouts and cauliflower by applying power ultrasound and its rehydration properties. Journal of Food Engineering, 81, 88–97.Jasinski, E. M., Stemberger, B., Walsh, R., & Kilara, A. (1984). Ultra structural studies of raw and processed tissue of the major cultivated mushroom, Agaricus bisporus. Food Microstructure, 3, 191–196.Jolivet, S., Arpin, N., Wicher, H. J., & Pellon, G. (1998). Agaricus bisporus browning: a review. Mycological Research, 102, 1459–1483.Konanayakam, M., & Sastry, S. K. (1988). Kinetics of shrinkage of mushroom during blanching. Journal of Food Science, 53(5), 1406–1411.Kotwaliwale, N., Bakane, P., & Verma, A. (2007). Changes in textural and optical properties of oyster mushroom during hot air drying. Journal of Food Engineering, 78(4), 1207–1211.Leadley C. & Williams A. (2002). Power ultrasound—current and potential applications for food processing, Review No 32, Campden and Chorleywood Food Research Association.Lespinard, A. R., Goñi, S. M., Salgado, P. R., & Mascheroni, R. H. (2009). Experimental determination and modeling of size variation, heat transfer and quality indexes during mushroom blanching. Journal of Food Engineering, 92, 8–17.Lima, M., & Sastry, S. K. (1990). Influence of fluid rheological properties and particle location on ultrasound-assisted heat transfer between liquid and particles. Journal of Food Science, 55(4), 1112–1115.López, P., & Burgos, J. (1995). Peroxidase stability and reactivation after heat treatment and manothermosonication. Journal of Food Science, 60(3), 551–553.López, P., Sala, F. J., Fuente, J. L., Cardon, S., Raso, J., & Burgos, J. (1994). Inactivation of peroxidase lipoxigenase and phenol oxidase by manothermosonication. Journal of Agricultural and Food Chemistry, 42(2), 253–256.Mansfield, T. (1962). High temperature-short time sterilization. Proceedings First International Congress on Food Science and Technology, 4, 311–316.Mason T. J. (1998). Power ultrasound in food processing—the way forward. In M. J. W. Povey & T. J. Mason (Eds.), Ultrasound in Food Processing (pp 103–126). Blackie Academic & Professional, London.McArdle F. J. & Curwen D. (1962). Some factors influencing shrinkage of canned mushrooms. Mushroom Science, 5, 547–557.McArdle, F. J., Kuhn, G. D., & Beelman, R. B. (1974). Influence of vacuum soaking on yield and quality of canned mushrooms. Journal of Food Science, 39, 1026–1028.Mohapatra, D., Bira, Z. M., Kerry, J. P., Frías, J. M., & Rodrigues, F. A. (2010). Postharvest hardness and color evolution of White button mushrooms (Agaricus bisporus). Journal of Food Science, 75(3), 146–152.Ohlsson, T. (1980). Temperature dependence of sensory quality changes during thermal processing. Journal of Food Science, 45(4), 836–847.Ortuño, C., Martínez-Pastor, M., Mulet, A., & Benedito, J. (2013). Application of high power ultrasound in the supercritical carbon dioxide inactivation of Saccharomyces cerevisiae. Food Research International, 51, 474–481.Peralta-Jimenez, L., & Cañizares-Macías, M. P. (2012). Ultrasound-assisted method for extraction of theobromine and caffeine from cacao seeds and chocolate products. Food and Bioprocess Technology, 6, 3522–3529.Rodríguez-López, J. N., Fenoll, N. G., Tudela, J., Devece, C., Sánchez-Hernández, D., De los Reyes, D., et al. (1999). Thermal inactivation of mushroom polyphenoloxidase employing 2450 MHz microwave radiation. Journal of Agricultural Food Chemistry, 47, 3028–3035.Sala, F., Burgos, J., Condon, S., Lopez, P., & Raso, J. (1995). Effect of heat and ultrasound on microorganisms and enzymes. In G. W. Gould (Ed.), New methods of food preservation (1st ed., pp. 176–204). Glasgow: Blackie Academic and professional.Sanjuán, N., Hernando, I., Lluch, M. A., & Mullet, A. (2005). Effects of low temperature blanching on texture, microstructure and rehydration capacity of carrots. Journal of the Science of Food and Agriculture, 85, 2071–2076.Santos, M. V., & Lespinard, A. R. (2011). Numerical simulation of mushrooms during freezing using the FEM and an enthalpy—Kirchhoff formulation. Heat and Mass Transfer, 47, 1671–1683.Sastry, S. K., Beelman, R. B., & Speroni, J. J. (1985). A three-dimensional finite element model for thermally induced changes in foods: application to degradation of agaritine in canned mushrooms. Journal of Food Science, 50(5), 1293–1299.Sastry, S. K., Shen, G. Q., & Blaisdel, J. L. (1989). Effect of ultrasonic vibration on fluid-to-particule convective heat transfer coefficients. Journal of Food Science, 54(1), 229–230.Sensoy, I., & Sastry, S. K. (2004). Ohmic blanching of mushrooms. Journal of Food Process Engineering, 27(1), 1–15.Sheen, S., & Hayakawa, K. (1991). Finite difference simulation for heat conduction with phase change in an irregular food domain with volumetric change. International Journal of Heat and Mass Transfer, 34(6), 1337–1346.Simal, S., Benedito, J., Sanchez, E. S., & Rossello, C. (1998). Use of ultrasound to increase mass transport rates during osmotic dehydration. Journal of Food Engineering, 36, 323–336.Siró, I., Vén, C., Balla, C., Jónás, G., Zeke, I., & Friedrich, L. (2009). Application of an ultrasonic assisted curing technique for improving the diffusion of sodium chloride in porcine meat. Journal of Food Engineering, 91, 353–362.Soria, A. C., & Villamiel, M. (2010). Effect of ultrasound on the technological properties and bioactivity in foods: a review. Trends in Food Science and Technology, 21, 323–331.Verlinden, B. E., Yuksel, D., Baheri, M., De Baerdemaeker, J., & Van Dijk, C. (2000). Low temperature blanching effect on the changes in mechanical properties during subsequent cooking of three potato cultivars. International Journal of Food Science and Technology, 35, 331–340.Wu, C. M., Wu, J. L.-P., Chen, C.-C., & Chou, C.-C. (1981). Flavor recovery from mushroom blanching water. In G. Charalambous & G. Inglett (Eds.), The quality of foods and beverages: chemistry and technology, vol. 1. New York: Academic Press.Zivanovic, S., & Buescher, R. (2004). Changes in mushroom texture and cell wall composition affected by thermal processing. Journal of Food Science, 69, 44–48

Risk factors and a predictive model for under-five mortality in Nigeria: evidence from Nigeria demographic and health survey

<p>Abstract</p> <p>Background</p> <p>Under-5 mortality is a major public health challenge in developing countries. It is essential to identify determinants of under-five mortality (U5M) childhood mortality because these will assist in formulating appropriate health programmes and policies in order to meet the United Nations MDG goal. The objective of this study was to develop a predictive model and identify maternal, child, family and other risk factors associated U5M in Nigeria.</p> <p>Methods</p> <p>Population-based cross-sectional study which explored 2008 demographic and health survey of Nigeria (NDHS) with multivariable logistic regression. Likelihood Ratio Test, Hosmer-Lemeshow Goodness-of-Fit and Variance Inflation Factor were used to check the fit of the model and the predictive power of the model was assessed with Receiver Operating Curve (ROC curve).</p> <p>Results</p> <p>This study yielded an excellent predictive model which revealed that the likelihood of U5M among the children of mothers that had their first marriage at age 20-24 years and ≥ 25 years declined by 20% and 30% respectively compared to children of those that married before the age of 15 years. Also, the following factors reduced odds of U5M: health seeking behaviour, breastfeeding children for > 18 months, use of contraception, small family size, having one wife, low birth order, normal birth weight, child spacing, living in urban areas, and good sanitation.</p> <p>Conclusions</p> <p>This study has revealed that maternal, child, family and other factors were important risk factors of U5M in Nigeria. This study has identified important risk factors that will assist in formulating policies that will improve child survival.</p

Optogenetic Manipulation of Cerebellar Purkinje Cell Activity In Vivo

Purkinje cells (PCs) are the sole output neurons of the cerebellar cortex. Although their anatomical connections and physiological response properties have been extensively studied, the causal role of their activity in behavioral, cognitive and autonomic functions is still unclear because PC activity cannot be selectively controlled. Here we developed a novel technique using optogenetics for selective and rapidly reversible manipulation of PC activity in vivo. We injected into rat cerebellar cortex lentiviruses expressing either the light-activated cationic channel channelrhodopsin-2 (ChR2) or light-driven chloride pump halorhodopsin (eNpHR) under the control of the PC-specific L7 promoter. Transgene expression was observed in most PCs (ChR2, 92.6%; eNpHR, 95.3%), as determined by immunohistochemical analysis. In vivo electrophysiological recordings showed that all light-responsive PCs in ChR2-transduced rats increased frequency of simple spike in response to blue laser illumination. Similarly, most light-responsive PCs (93.8%) in eNpHR-transduced rats decreased frequency of simple spike in response to orange laser illumination. We then applied these techniques to characterize the roles of rat cerebellar uvula, one of the cardiovascular regulatory regions in the cerebellum, in resting blood pressure (BP) regulation in anesthetized rats. ChR2-mediated photostimulation and eNpHR-mediated photoinhibition of the uvula had opposite effects on resting BP, inducing depressor and pressor responses, respectively. In contrast, manipulation of PC activity within the neighboring lobule VIII had no effect on BP. Blue and orange laser illumination onto PBS-injected lobule IX didn't affect BP, indicating the observed effects on BP were actually due to PC activation and inhibition. These results clearly demonstrate that the optogenetic method we developed here will provide a powerful way to elucidate a causal relationship between local PC activity and functions of the cerebellum

Transforming Growth Factor β Signaling Pathway Associated Gene Polymorphisms May Explain Lower Breast Cancer Risk in Western Indian Women

Transforming growth factor β1 (TGFB1) T29C and TGF β receptor type 1 (TGFBR1) 6A/9A polymorphisms have been implicated in the modulation of risk for breast cancer in Caucasian women. We analyzed these polymorphisms and combinations of their genotypes, in pre menopausal breast cancer patients (N = 182) and healthy women (N = 236) from western India as well as in breast cancer patients and healthy women from the Parsi community (N = 48 & 171, respectively). Western Indian women were characterized by a higher frequency of TGFB1*C allele of the TGF β T29C polymorphism (0.48 vs 0.44) and a significantly lower frequency of TGFBR1*6A allele of the TGFBR1 6A/9A polymorphism (0.02 vs 0.068, p<0.01) as compared to healthy Parsi women. A strong protective effect of TGFB1*29C allele was seen in younger western Indian women (<40 yrs; OR = 0.45, 95% CI 0.25–0.81). Compared to healthy women, the strikingly higher frequencies of low or intermediate TGF β signalers in patients suggested a strong influence of the combination of these genotypes on the risk for breast cancer in Parsi women (for intermediate signalers, OR = 4.47 95%CI 1.01–19.69). The frequency of low signalers in Parsi healthy women, while comparable to that reported in Europeans and Americans, was three times higher than that in healthy women from western India (10.6% vs 3.3%, p<0.01). These observations, in conjunction with the low incidence rate of breast cancer in Indian women compared to White women, raise a possibility that the higher frequency of TGFB1*29C allele and lower frequency of TGFBR1*6A allele may represent important genetic determinants that together contribute to a lower risk of breast cancer in western Indian women