Influenza surveillance among children with pneumonia admitted to a district hospital in coastal Kenya, 2007-2010

Background: Influenza data gaps in sub-Saharan Africa include incidence, case fatality, seasonal patterns, and associations with prevalent disorders. Methods: Nasopharyngeal samples from children aged <12 years who were admitted to Kilifi District Hospital during 2007–2010 with severe or very severe pneumonia and resided in the local demographic surveillance system were screened for influenza A, B, and C viruses by molecular methods. Outpatient children provided comparative data. Results: Of 2002 admissions, influenza A virus infection was diagnosed in 3.5% (71), influenza B virus infection, in 0.9% (19); and influenza C virus infection, in 0.8% (11 of 1404 tested). Four patients with influenza died. Among outpatients, 13 of 331 (3.9%) with acute respiratory infection and 1 of 196 without acute respiratory infection were influenza positive. The annual incidence of severe or very severe pneumonia, of influenza (any type), and of influenza A, was 1321, 60, and 43 cases per 100 000 <5 years of age, respectively. Peak occurrence was in quarters 3–4 each year, and approximately 50% of cases involved infants: temporal association with bacteremia was absent. Hypoxia was more frequent among pneumonia cases involving influenza (odds ratio, 1.78; 95% confidence interval, 1.04–1.96). Influenza A virus subtypes were seasonal H3N2 (57%), seasonal H1N1 (12%), and 2009 pandemic H1N1 (7%). Conclusions: The burden of influenza was small during 2007–2010 in this pediatric hospital in Kenya. Influenza A virus subtype H3N2 predominated, and 2009 pandemic influenza A virus subtype H1N1 had little impact

The Influence of Environmental Temperature and Substrate Initial Moisture Content on \u3cem\u3eAspergillus niger\u3c/em\u3e Growth and Phytase Production in Solid−State Cultivation

Aspergillus niger is being used commercially for phytase production utilizing solid-state cultivation; however, no studies have been published that investigated the optimal environmental temperature and initial substrate water content to maximize fungal growth and/or phytase production. Solid-state cultivations of Aspergillus niger on wheat bran and soybean meal were conducted at three temperatures (25°C, 30°C, and 35°C) and three initial moisture contents (50%, 55%, and 60% wet basis) in a split-plot full-factorial experimental design. Fermentations were conducted for 0, 24, 48, 72, and 120 h. The containers were sampled destructively and assayed for phytase activity and glucosamine concentration as an estimate of fungal biomass. Temperature affected phytase activity production, but substrate initial moisture content did not. The highest phytase activity was found at 30°C, 50% to 60% initial moisture content, and 72 h of fermentation. Initial substrate moisture content affected glucosamine production after 72 and 120 h of fermentation. The maximum glucosamine was produced at 35°C, either 50% or 60% initial moisture content, and 120 h of fermentation. The results show that the optimal biomass growth conditions are not the same as the optimal phytase production conditions, suggesting that phytase production is not entirely correlated with fungal growth

Optimization of Solid-State Fermentation Parameters for the Production of Xylanase by \u3cem\u3eTrichoderma longibrachiatum\u3c/em\u3e on Wheat Bran

Solid-state fermentation has the potential to produce inexpensive enzymes for use in high-volume industrial applications. Process parameters such as substrate moisture content and length of fermentation can have a significant effect on the amount and timing of enzyme production. This study was conducted in two stages, a screening stage and an optimization stage, to determine the effects of moisture content of the substrate, surfactant addition upon inoculation, depth of the substrate, and duration of fermentation on xylanase activity produced by Trichoderma longibrachiatum. Screening fermentations were conducted at 25°C, 50 and 75% wet basis moisture content (w.b.), 0.0 and 0.2% v/v surfactant addition, 0.5 and 1.5 cm depth of wheat bran, and 5 and 10 days of fermentation. Optimization fermentations were conducted at 25°C, 45, 55, and 65% moisture content (w.b.), 1.0, 1.5, and 2.0 cm depth of wheat bran, and three and five days of fermentation. Experiments were conducted as full factorial experiments with three replications of each treatment. The optimal values of the process variables were selected based on the units of xylanase activity produced per gram of wheat bran (U/g). Moisture content, depth of substrate, and duration of fermentation had significant main effects on the production of enzyme activity. Surfactant addition upon inoculation had interaction effects with moisture content, and the duration of fermentation by moisture content interaction also was significant. The treatment of 55% moisture content, 1.5 cm depth of substrate, and five days of fermentation resulted in the highest average xylanase activity (716 U/g wheat bran)

Predicting the Cutting Time of Cottage Cheese Using Backscatter Measurements

An automated system for monitoring culture growth and determining coagulum cutting time is needed for cottage cheese manufacturing. A light backscatter measurement system was designed and installed in a local cottage cheese manufacturing plant. A cutting time prediction algorithm was developed using parameters generated from the backscatter profile. The cutting time prediction algorithm, Tcut = Tmax + β2 S, used two time-based parameters generated from the backscatter profile (Tmax and S) and one operator selected parameter, β2, to predict the coagulum cutting time, Tcut. The standard error of prediction for the algorithm was 6.4 min and was an improvement over the standard error of 8.7 min previously reported (Payne et al., 1998). The algorithm is more robust than that used by Payne et al. (1998) because it predicts cutting time based on a measure of coagulation kinetics, S, and eliminates the uncertainty of the culture starting time from the algorithm. In addition, a method was proposed for continuous monitoring of culture growth during the first 210 min of the process

Optimization of Solid-State Fermentation Parameters for the Production of Xylanase by \u3cem\u3eTrichoderma longibrachiatum\u3c/em\u3e on Wheat Bran in a Forced Aeration System

The effect of aeration on the production of xylanase by Trichoderma longibrachiatum on wheat bran in a solid-state fermentation (SSF) system has not been investigated. This study was conducted to investigate the interactive effects of aeration, initial moisture content of the substrate, and depth of the substrate on xylanase activity produced in a tray fermenter. The experiment was conducted as a split plot experiment with factorial treatments and three replications of each treatment combination. The whole plot treatment was aeration rate (0, 2.9, 5.7 L/min/kg bran). Initial moisture content (45, 55, 65% w.b.) and depth of substrate (1.0 and 2.5 cm) were investigated factorially. Trays of wheat bran were assayed after fermentation by Trichoderma longibrachiatum to determine the production of xylanase activity. Aeration rate had a significant nonlinear effect on enzyme activity with highest yields obtained at an aeration rate of 2.9 L/min/kg bran (738 U/g, averaged over all initial moisture contents and depth of substrates). Initial moisture content of the substrate also had a significant nonlinear effect on enzyme activity with the highest yields at 55% (556 U/g, averaged over all airflow rates and depths of substrate). Depth of substrate had no significant statistical effect on enzyme activity. The treatment combination of 2.9 L/min/kg airflow rate and 55% moisture content resulted in the highest yields (948 U/g, averaged over depth of substrate)

LOWER LIMB LANDING BIOMECHANICS ON NATURAL AND FOOTBALL TURF

The aim of the study was to investigate variation in lower limb kinematics during jump landings on natural (NT) and artificial Football Turf (FT). One footballer performed 30 single leg jump landings, following a ball heading movement on NT and FT and immediately continued into a two-step forward run. Landing limb kinematics were recorded (200Hz) using CODA™ and cluster markers. There were similar knee and ankle touchdown kinematics and differing joint angle profiles throughout. FT landings showed greater knee flexion, adduction and internal rotation and reduced ankle eversion. During early impact, the ankle showed a tendency for greater plantar-flexion and inversion using FT compared to NT. These observations highlight a potential for altered lower limb kinematics on NT and FT which may be exaggerated during more demanding tasks and warrant further investigation

Effects of Growth Media pH and Reaction Water Activity on the Conversion of Acetophenone to (S)-1-Phenylethanol by \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e Immobilized on Celite 635 and in Calcium Alginate

Biologically catalyzed reactions often produce enantiomers of the product; however, only one configuration is desired. Reaction conditions are known to affect enantiomer ratios and reaction kinetics, but little is known regarding the effect of processing conditions on whole-cell biocatalysis. Saccharomyces cerevisiae cells were grown in batch on glucose at pH = 4, 5, and 7, and then immobilized on Celite beads or in calcium alginate beads and used as the biocatalyst for the conversion of acetophenone in hexane to (S)-1-phenylethanol at water activities of 0.37, 0.61, and 0.80. S. cerevisiae was used as a model microorganism for the whole-cell catalyzed reaction. The initial reaction rate (IRR) and the final (S)-1-phenylethanol concentration were quantified for each treatment. The highest IRR value (94.9 µmol/h) and the highest final concentration of (S)-1-phenylethanol (17.8 mM) were observed on Celite-immobilized cells grown at pH 5 or 7, with the main effect of growth medium pH highly statistically significant. The main effect of water activity and the interactions of the two were not statistically significant (a = 0.05). The cells immobilized in calcium alginate beads favored a water activity of 0.61, resulting in an IRR of 916.2 µmol/h/g dcw, averaged over pH. The highest final concentration of (S)-1-phenylethanol (4.8 mM) was achieved with cells grown at pH 5 or 7. Calcium alginate beads gave the highest initial reaction rate with a growth pH of 7 and a water activity of 0.61. However, pH of 5 and water activity of 0.61 resulted in the highest final concentration of (S)-1-phenylethanol

Light Backscatter of Milk Products for Transition Sensing Using Optical Fibers

Transition sensors are needed, particularly in the dairy industry, for detecting transitions in pipe flow systems from product-to-water or product-to-product (such as from chocolate to vanilla ice cream mix). Transition information is used to automatically sequence valves to minimize product waste. Optical fibers were used to measure light backscatter between 400 and 950 nm as a function of milk concentration in water and milkfat concentration in milk. The normalized response (100% for product and 0% for water) as a function of product concentration in water was approximately logarithmic for skim milk between 400 and 900 nm and approximately linear for milk containing 1, 2, and 3.2% milkfat. The backscatter ratio (response relative to that for skim milk) as a function of milkfat in milk was wavelength dependent with longer wavelengths being more sensitive. The backscatter ratio at 900 nm for milk containing 3.2% homogenized fat was nearly four times that for skim milk. Backscatter ratio saturated (minimal response with increased milkfat) at 8% milkfat for homogenized cream and 16% milkfat for unhomogenized cream. Light backscatter for near infrared wavelengths around 900 nm was found ideally suited for transition sensing of dairy products and was found particularly sensitive to milkfat content. Light backscatter was found less suitable for discriminating between high milkfat products

Toward Biochemical Conversion of Lignocellulose On-Farm: Pretreatment and Hydrolysis of Corn Stover \u3cem\u3eIn Situ\u3c/em\u3e

High-solids lignocellulosic pretreatment using NaOH followed by high-solids enzymatic hydrolysis was evaluated for an on-farm biochemical conversion process. Increasing the solids loadings for these processes has the potential for increasing glucose concentrations and downstream ethanol production; however, sequential processing at high-solids loading similar to an on-farm cellulose conversion system has not been studied. This research quantified the effects of high-solids pretreatment with NaOH and subsequent high-solids enzymatic hydrolysis on cellulose conversion. As expected, conversion efficiency was reduced; however, the highest glucose concentration (40.2 g L-1), and therefore the highest potential ethanol concentration, resulted from the high-solids combined pretreatment and hydrolysis. Increasing the enzyme dosage improved cellulose conversion from 9.6% to 36.8% when high-solids loadings were used in both unit operations; however, increasing NaOH loading and pretreatment time did not increase the conversion efficiency. The enzyme-to-substrate ratio had a larger impact on cellulose conversion than the NaOH pretreatment conditions studied, resulting in recommendations for an on-farm bioconversion system

Fiber Optic Sensor Response to High Levels of Fat in Cream

A light backscatter technique using optical fibers to deliver and receive light was investigated for measuring the milkfat content of unhomogenized cream. Light backscatter through cream at wavelengths of 450 to 900 nm was measured for fiber separation distances from 2 to 6.5 mm and for cream containing 10 to ~40 weight percent (wt%) milkfat. Unhomogenized cream (~40 wt% milkfat) was mixed with skim milk (~0.05 wt% milkfat) to yield samples with five different milkfat levels. Three optical response models were tested for correlation with milkfat content: one using the light intensity measurement at a single separation distance, the second using the ratio of the light intensity at two distances, and a third using the light intensity as a function of separation distance based on the backscatter of light in a particulate solution. The calibration equations from all three methods were used to predict milkfat content in the evaluation samples with root mean square errors (RMSEs) of 1.5 to 2.0 wt%. Statistical analysis did not find a significant difference between the three methods. For simplicity, using the ratio of the intensities measured and two different separation distances is attractive for further sensor design