Performance of the Production Band 3 receivers (84-116 GHz) for the Atacama Large Millimeter Array (ALMA)

This paper presents the performance of production Band 3 receivers (84-116 GHz) for the Atacama Large Millimeter Array (ALMA) that operate in Chile at 5000 m altitude. The fabrication, and testing of a total of 73 receivers necessitated stringent quality control during assembly and custom designed automated test set for accurate and reproducible measurement results. Interfaces to the ALMA receiver system are described in details. The average single side band noise temperature of band 3 production receivers is 33.2 K, with a minimum of 24.4 K and a maximum of 45.5 K. As for image rejection, the average is 18 dB, with a minimum at 12 dB and a maximum of 21 dB. Other performances with test methodology are described such as gain variation within the IF band, the gain and phase stability, gain compression, and beam patterns. This paper also describes the interfaces to the ALMA front end system, the testing methodology used, and the test results.     

Physicochemical Characteristics of Date Sap “Lagmi” from Deglet Nour Palm (Phoenix Dactylifera L.)

Physicochemical properties of sap from Deglet Nour date palm (Phoenix dactylifera L.) were studied. Composition analysis revealed (on a dry-weight basis) a high content of carbohydrates (94.98 g/100 g of dry matter basis) mainly sucrose, 2.72 g/100g (dry matter basis) of proteins and 2.29 g/100 g (dry matter basis) of ash. Date palm sap also contains 7.64 mg gallic acid equivalent/100 ml of total polyphenol. Thus, date palm sap showed antioxidant activity with a percentage inhibition of the DPPH radical value of 47.64%. Surface and foaming properties were also performed by drop volume and bubbling method, respectively. Equilibrium surface tension of fresh sap was 63.51 mN/m. Freeze-drying method preserved surface activity. Native sap showed better foam power (1.03) and foam stability (1150 s) than solutions prepared from lyophilised sap (5–30 g /100g of solution). Results demonstrated that this natural juice could be regarded as functional food due to its high nutritional value, antioxidant activity, surface activity, and foam power.     

Depuration and Relaying: A Review on Potential Removal of Norovirus from Oysters

Pollution of coastal waters can result in contamination of bivalve shellfish with human enteric viruses, including norovirus (NoV), and oysters are commonly implicated in outbreaks. Depuration is a postharvest treatment involving placement of shellfish in tanks of clean seawater to reduce contaminant levels; this review focuses on the efficacy of depuration in reducing NoV in oysters. There have been many NoV outbreaks from depurated oysters containing around 10³ genome copies/g oyster tissue, far exceeding the median infectious dose (ID50). Half of the published NoV reduction experiments showed no decrease in NoV during depuration, and in the remaining studies it took between 9 and 45.5 d for a 1‐log reduction—significantly longer than commercial depuration time frames. Surrogate viruses are more rapidly depurated than NoV; the mean number of days to reduce NoV by 1 log is 19, and 7.5 d for surrogates. Thus, surrogates do not appear to be suitable for assessing virological safety of depurated oysters; data on reduction of NoV infectivity during depuration would assist evaluations on surrogate viruses and the impact of methods used. The longer persistence of NoV highlights its special relationship with oysters, which involves the binding of NoV to histo‐blood group‐like ligands in various tissues. Given the persistence of NoV and on‐going outbreaks, depuration as currently performed appears ineffective in guaranteeing virologically safe oysters. Conversely, relaying oysters for 4 wk is more successful, with low NoV concentrations and no illnesses associated with products. The ineffectiveness of depuration emphasizes the need for coastal water quality to be improved to ensure oysters are safe to eat.     

Challenges in the addition of probiotic cultures to foods

Probiotic cultures are increasingly being added to foods in order to develop products with health-promoting properties. Although the literature is abundant on the beneficial effects of bifidobacteria and Lactobacillus acidophilus on health, little information is available on the challenges industry faces in adding these probiotic cultures to food products. The aim of this article is to examine seven issues that should be addressed when developing functional foods: 1) type or form of probiotic that should be used; 2) addition level required to have a beneficial effect; 3) toxicity; 4) effect of the processing steps on viability; 5) determination, in the product, of the cell populations added; 6) stability during storage; 7) changes in sensory properties of the foods.     

Occurrence of perfluorooctane sulfonate and other perfluorinated alkylated substances in harbor porpoises from the Black Sea

Perfluorooctane sulfonate (PFOS) and other perfluorinated alkylated substances (PFAS) were determined in liver, kidney, muscle, brain, and blubber samples of 31 harbor porpoises (Phocoena phocoena relicta) of different age and sex stranded along the Ukrainian coast of the Black Sea. In all individuals and in all tissues, PFOS was the predominant PFAS, accounting for on average 90% of the measured PFAS load. PFOS concentrations were the highest in liver (327+/-351 ng/g wet wt) and kidney (147 +/-262 ng/g wet wt) tissue, and lower in blubber (18+/-8 ng/g wet wt), muscle (41+/-50 ng/g wet wt), and brain (24 +/-23 ng/g wetwt). No significant differences could be determined between males and females, nor between juvenile and adult animals (p > 0.05). Perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, and perfluorododecanoic acid could be detected in liver tissue of approximately 25% of the individuals. Perfluorobutane sulfonate, perfluorobutanoic acid, and perfluorooctanoic acid were not detected in any of the porpoise livers. Although we investigated a potential intraspecies segregation according to the source of prey, using stable isotopes, no statistically significant correlation between PFOS concentrations and stable isotopes could be determined. It is, however, noteworthy that the contamination by PFOS in the Black Sea harbor porpoises is comparable to levels found in porpoises from the German Baltic Sea and from coastal areas near Denmark and, therefore, might pose a threat to this population.     

Arginine and nitric oxide synthase: Regulatory mechanisms and cardiovascular aspects

l ‐Arginine (l ‐Arg) is a conditionally essential amino acid in the human diet. The most common dietary sources of l ‐Arg are meat, poultry and fish. l ‐Arg is the precursor for the synthesis of nitric oxide (NO); a key signaling molecule via NO synthase (NOS). Endogenous NOS inhibitors such as asymmetric‐dimethyl‐l ‐Arg inhibit NO synthesis in vivo by competing with l ‐Arg at the active site of NOS. In addition, NOS possesses the ability to be “uncoupled” to produce superoxide anion instead of NO. Reduced NO bioavailability may play an essential role in cardiovascular pathologies and metabolic diseases. l ‐Arg deficiency syndromes in humans involve endothelial inflammation and immune dysfunctions. Exogenous administration of l ‐Arg restores NO bioavailability, but it has not been possible to demonstrate, that l ‐Arg supplementation improved endothelial function in cardiovascular disease such as heart failure or hypertension. l ‐Arg supplementation may be a novel therapy for obesity and metabolic syndrome. The utility of l ‐Arg supplementation in the treatment of l ‐Arg deficiency syndromes remains to be established. Clinical trials need to continue to determine the optimal concentrations and combinations of l ‐Arg, with other protective compounds such as tetrahydrobiopterin (BH₄), and antioxidants to combat oxidative stress that drives down NO production in humans.     

Assay of a potential post‐harvest handling procedure for cantaloupe Charentais melon fruit with inhibited ethylene production

Antisense ACC‐oxidase Cantaloupe Charentais melons, unsuitable for autocatalytic ethylene production, were harvested at different ages and exposed to a standard post‐harvest manipulation to reproduce the handling chain that occurs from harvesting to retail sale. The stages were as follows: storage in a chamber at 2 °C during 2 or 3 weeks, second storage at 8 °C for 4 days, treatment with 50 ppm ethylene for 2 days and, finally, maintenance at 20 °C for four more days. The date of harvest and the different periods of storage at 2 °C assayed did not affect the final de‐greening of the rind, while the change in pulp colour depended on the harvest date. Storage conditions also influenced the texture of the pulp and acidity. Weight loss was dependent mainly on date of harvest, like soluble solids content, although the period of storage at 2 °C influenced too. The impact of cold on the appearance of the fruits is discussed. Copyright © 2007 Society of Chemical Industry     

Suitability of the Weibull four‐parameters model to predict the induction phase of α‐amylase production during red sorghum malting when a steep in dilute NaOH is used prior to a re‐steep in a Bacillus subtilis‐S499 based treatment

In previous studies, Bacillus subtilis has been used to control mould growth during red sorghum malting. The use of this biocontrol in steeping liquor has been optimized with some success and the combined use of a 0.2% NaOH steep, followed by a re‐steep in a B. subtilis‐based biocontrol, has been proposed. The sharpness and variability of the β‐amylase peak and the higher levels of β‐glucanase, obtained in the presence of B. subtilis cells, were highlighted. In this work, the suitability of the Weibull four‐parameters model to predict sorghum malt α‐amylase activity during the enzyme induction stage of red sorghum germination has been compared with that of a second order polynomial model and a general linear model. Results obtained showed that the Weibull four‐parameters model could be used to predict α‐amylase activity, with significant goodness of fit when compared with the second order polynomial model and the general linear model. The effects of steeping treatment (combined use of 0.2% NaOH and B. subtilis‐S499 starters) and the germination temperature are presented. When the B. subtilis culture used as a starter was diluted, the treatment efficacy to develop α‐amylase activity was lost. This study also showed that the germination temperature affected the α‐amylase activity rate increase during the induction phase. Copyright © 2013 The Institute of Brewing & Distilling