Measurement of the thermal expansion coefficient of an all-sapphireoptical cavity

We present measurements of the frequency-temperature dependence of an all-sapphire Fabry-Perot optical cavity to be used as an optical frequency reference. Measurements were made by tracking the frequency of the cavity relative to a second high-stability cryogenic sapphire-spaced cavity-a technique with impressive resolution for measurements of the coefficient of thermal expansion (CTE). Measurements presented here cover the temperature range of 11 K to 26 K. We find that the CTE of the all-sapphire cavity for these temperatures is given by α_cavity=(7.7±0.9)×10^$ -¹³ T/sup (3.23±0.05/)     

Potential for improvement in yeast nutrition in raw whole grain sorghum and maize lager brewing and bioethanol production through grain genetic modification and phytase treatment

Brewing and bioethanol production with raw grain and exogenous enzymes produces wort with satisfactory hot water extract (HWE). However, the free amino nitrogen (FAN) and mineral content can be too low, owing to low protein digestibility (PD) and phytate–mineral chelation, respectively. This study evaluated the potential for improvement in yeast nutrition in raw whole sorghum and maize brewing and bioethanol production by genetic modification (GM) of sorghum to improve PD and reduce phytate content, and by treatment with exogenous phytase. While phytase addition decreased sorghum spent grain phytate content (88%) and content of minerals (17 to 59%; i.e. increased wort mineral content), it did not affect maize phytate spent grain mineral content or HWE significantly. However, phytase addition did increase maize wort FAN (20%), sorghum HWE (2.8 percentage points) and wort FAN (23%). GM sorghum gave reduced spent grain mineral contents (11–38%), increased HWE (5.5 percentage points) and wort FAN (71%). Hence, genetic modification of sorghum to improve PD and reduce phytate content has considerable potential in raw grain brewing and bioethanol production to improve yeast nutrition. Copyright © 2012 The Institute of Brewing & Distilling     

Satisfying America's Fruit Gap: Summary of an Expert Roundtable on the Role of 100% Fruit Juice

The 2015 to 2020 Dietary Guidelines for Americans (DGAs) recognize the role of 100% fruit juice in health and in helping people meet daily fruit recommendations and state that 100% fruit juice is a nutrient‐dense beverage that should be a primary choice, along with water and low‐fat/fat‐free milk. The DGAs note that children are consuming 100% fruit juice within recommendations (that is, 120 to 180 mL/d for children aged 1 to 6 y and 236 to 355 mL/d for children aged 7 to 18 y). Evidence shows that compared to nonconsumers, those who consume 100% fruit juice come closer to meeting daily fruit needs and have better diet quality. In children, 100% fruit juice is associated with increased intakes of nutrients such as vitamin C, folate, and potassium. When consumed within the DGA recommendations, 100% fruit juice is not associated with overweight/obesity or childhood dental caries and does not compromise fiber intake. Preliminary data suggest that polyphenols in some 100% fruit juices may inhibit absorption of naturally occurring sugars. Given its role in promoting health and in helping people meet fruit needs, experts participating in a roundtable discussion agreed that there is no science‐based reason to restrict access to 100% fruit juice in public health nutrition policy and programs such as the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Reducing or eliminating 100% fruit juice could lead to unintended consequences such as reduced daily fruit intake and increased consumption of less nutritious beverages (for example, sugar‐sweetened beverages).     

Development of a method to measure rheological properties of carrot cell and cell-wall materials

A method for measuring the rheological properties of carrot cells and cell-wall material during typical cooking conditions has been evaluated. A Bohlin controlled-stress rheometer with a rapid heating attachment was used. Because of potential slippage and sensitivity problems with cells and cell-wall material, different geometries (parallel plate, cone and plate, and concentric cylinder) were assessed. Initial experiments were designed to determine the linear viscoelastic regions for the cell and cell-wall materials at 25°C. Samples were subjected to varying shear stresses and oscillatory frequencies. For carrot cells, linearity was observed with cone and plate geometry and with concentric cylinder geometry over a fairly wide range of stresses and frequencies. Parallel plate geometry did not give linear results. Carrot cell-wall material behaved in a linear fashion with all three geometries over similar stress and frequency ranges as carrot cells. Using the appropriate conditions of geometry, frequency and stress, the influence of heat treatments on cell and cell-wall rheology was compared. A comparison of cone and plate and concentric cylinder geometry was performed using cells and cell-wall material heated from 25 to 90°C. Cone and plate geometry showed greater changes in rheological properties during heating than concentric cylinder geometry and also allowed a greater range of heating rates. Cone and plate geometry was used in further studies. Studies on the rheological behaviour of cells during heating showed that the complex shear modulus (G^*) increased in the range 25–75°C then decreased. For cell-wall material, G^* showed a steady increase from 25 to 90°C. Further experiments demonstrated that the increase in G^* was not due to water loss during heating. The amount of cell damage during heating was measured using a conductivity meter to establish if there was a correlation between changes in G^* and cell damage.     

Characteristics of rennet–casein-based model processed cheese containing maize starch: Rheological properties,meltabilities and microstructures

The rheological properties, meltabilities and microstructural properties of rennet–casein-based model processed cheese slices containing normal maize starch, waxy maize starch and high amylose (70%) maize starch (HAMS) were investigated as a function of the ratio of starch to protein. The storage modulus (G′) increased with increasing ratio of normal maize starch to protein in the processed cheeses, whereas G′ decreased with the addition of waxy maize starch. The tan δ values at high temperature (90 °C) decreased with the addition of both normal maize starch and waxy maize starch, but normal maize starch caused a greater reduction in the tan δ values. These properties were influenced to a lesser extent in processed cheeses containing HAMS. Processed cheeses containing normal maize starch lost meltability at ratios of starch to protein > 0.16; waxy maize starch and HAMS had less influence on the meltability. The effect of starch on the properties of the processed cheeses was attributed to phase behaviours between the protein and the starch, which was shown in confocal laser scanning micrographs.     

Chylothorax: report of a case complicating ductus ligation through a median sternotomy, and review

An unusual case of chylothorax is described in a 4-year-old child after repair of a ventricular septal defect and ligation of a patent ductus arteriosus through a median sternotomy. Left chylothorax developed after a latent period of six days and was treated initially with continuous drainage and parenteral supplementation of proteins and lipids. Operative intervention with oversewing of the site of the leak in the anterior mediastinum proved necessary after three weeks. The anatomical variations of the thoracic duct are outlined to explain the occurrence of chylothorax after diverse intrathoracic operations. The physiological effects of a thoracic duct fistula and various aspects of management are reviewed.     

Autoflora in the upper respiratory tract of Apollo astronauts

The typical microbial inhabitants of the oral and nasal cavities of Apollo astronauts were identified before space flight and generally found to be similar to those previously reported for healthy male adults. Additional analyses of samples collected immediately after return of the Apollo 13, 14, 15, and 16 crew members to earth were performed to evaluate the effects of space travel on the microbial bioburden of the upper respiratory tract. In-flight cross-contamination and buildup of pathogens such as Staphylococcus aureus were noted, although significant increases in nonpathogenic species were absent. Other proposed alterations, such as dysbacteriosis (flooding of the mouth with a single species) and simplification of the autoflora, did not occur. Generally, the incidence and quantitation of each species after flight was within the preflight range, although the number of viable Haemophilus cells recovered from the mouth decreased significantly after space flight. Except for those minor alterations listed above, the aerobic and anaerobic bacterial components of the upper respiratory autoflora of Apollo astronauts was found to be stable after space flight of up to 295 h.     

Recurrent hypernatremia; a proposed mechanism in a patient with absence of thirst and abnormal excretion of water

A 7-year-old girl twice developed severe hypernatremia (serum sodium values up to 194 mEq/l) without obvious cause. The ability of her kidneys to conserve water was normal, and increasing her plasma osmolality stimulated an appropriate ADH response. Unable to excrete a water load, her kidneys continued to conserve water even with a serum sodium concentration of 133 mEq/l. She was never thirsty and did not ingest sufficient fluid by choice. Although there was no demonstrable anatomic lesion, we postulate a localized defect of her thirst center. This may have modified release of ADH and resulted in an inability to dilute the urine by interrupting a pathway that could exist from the thirst center to the supraoptic nuclei. A therapeutic regimen based on these studies has prevented further hypernatremia.