Correlation study between standard plate count and flow cytometry for determination of raw milk total bacterial count

Milk samples were collected in the dry season ( n =  155) and in the rainy season ( n =  68) to establish a correlation between electronic flow cytometry and standard plate count for the determination of total bacterial count of raw milk. Results were expressed in individual bacterial count (ibc) and colony forming unit (cfu) for electronic flow cytometry (Bactocount) and standard plate count, respectively. The accuracy of Bactocount, denoted by the residual standard deviation ( s ( y,x )), was 0.309 log cfu/mL. The predictive interval of estimated values was broad and it is suggested that total bacterial count should be expressed in ibc without transformation to cfu.     

Polyphosphates as inhibitors of surface mould growth on hard cheese during ripening

A novel treatment using polyphosphates to protect cheeses against superficial mould growth was assayed. The treatments were: control commercial paint with natamycin (I), commercial paint based on polyvinyl–water (II), immersion in a saturated solution of polyphosphate (III), immersion and commercial paint (IV), commercial paint of polyphosphate solutions (V) and immersion and commercial paint of a saturated solution of polyphosphates (VI). The cheeses were ripened for 6 months. Superficial mould growth was inhibited in groups IV and VI when compared to cheeses from the control group (I). Statistical sensory analysis made between cheeses from groups IV and I (control) showed no significant differences.     

On the stability of a class of non-linear continuous systems†

A procedure to find the existence and domain of asymptotic stability for a class of systems described by a set of non-linear partial differential equations is presented in the context of semigroup theory.

No a priori bound is imposed on the non-linearity which is assumed to be a quad ratic (bilinear) or multilinear form.

The linearized system can be non-self-adjoint and need not be asymptotically stable equation by equation.

The solution of the stability problem is carried out. in two steps :

(a) the development of an L₂-like norm that bounds above the sup norm, a requirement to obtain a useful estimate of the non-linear term, and

(a)the computation of an estimate of the L₂-likc norm of the semigroup generated by the linearized system in terms of its usual L₂ norm.     

MULTIVARIATE STATISTICAL ANALYSIS OF VOLATILE COMPOUNDS AS A CRITERION FOR SELECTING TECHNOLOGICAL PARAMETERS IN THE OSMOTIC DEHYDRATION OF PINEAPPLE

Principal component analysis and cluster analysis of volatile compounds were used for selecting technological parameters in the osmotic dehydration of pineapple. Assessment of volatile losses permitted differentiation between samples obtained by different osmotic treatments. Treatments at 30C for 1 h at atmospheric pressure or under vacuum and at 30C or 40C for 1 to 3 h with pulsed vacuum (1 cycle) produce the lowest losses of volatile compounds. Apparently, pulsed vacuum allows higher aromatic volatiles retention than two other pressure modes. It also allows increases in both process temperature and time without an important increase in losses.     

2,3-DIHYDROXYBENZOIC ACID AS A SUBSTRATE FOR MUSHROOM TYROSINASE1,2

When 2, 3-dihydroxybenzoic acid (2, 3-DBA) is acted upon by mushroom tyrosinase, a yellow intermediate, 2, 3-DBA-o-quinone, characterized by a peak at 415 nm, is the first product detected. 2, 3-DBA-o-quinone gives rise to a “final blue product” (λmax = 230, 410, 620 nm), and to “soluble oxidation product(s)” (λmax = 275–280, 350–360 nm). Kinetic data (assayed spectrophotometrically and polarographically) obtained when different concentrations of 2, 3-DBA were oxidized by a fixed amount of mushroom tyrosinase, deviated from classic Michaelis-Menten kinetics. Reduction of the “final blue product” with ascorbate resulted in the loss of the blue chromophore at 620 nm and the concomitant appearance of a “yellowish reduced final product.” The “yellowish reduced final product” could be reoxidized with either mushroom tyrosinase or with NaIO4 to the “final blue product,” indicating that the latter has carbonylic quinonoid groups in ortho position to each other.     

Modernism Made Vernacular: The Brazilian Case

From its early acceptance in the 1940s and 1950s, modern architecture in Brazil has become the vernacular, adapted and adopted by the middle class with the help of contractors and unskilled laborers. Even the poorest favelas are constructed using modernist principles on a scale unmatched in developed nations. The Brazilian case highlights a number of issues regarding the relationship between modernism and vernacular architecture, a topic insufficiently explored in architectural scholarship outside Europe and North America.