The daily variations of airborne fungal spores in Mexico City

The daily and seasonal distribution of airborne fungal particles was recorded in a high altitude tropical zone. Sampling was carried out in the southern part of Mexico City. An Andersen air sampler was used over a period of six months. Ten minutes sampling for each set of plates was done at fixed schedule: 07:30, 14:00 and 19:00 hours. The sampler was placed 10 m above the ground. Daily variation was found to be associated with the season, weather and atmospheric stability. The highest value of mold counts (3195 CFU m⁻³) was recorded in the evening on October, a transitional month between the rainy and the dry seasons, the lowest (45 CFU m⁻³) at noon during the rainy season. Mold counts were significantly correlated with temperature, having negative signs both in the morning and at noon, and being positive in the evening. The abundance of only three genera was recorded.Cladosporium, was isolated more frequently, and its abundance at 14:00 h was of 38%;Alternaria represented 4.0%, at 14:00 h, andAspergillus 3.0% at 7:30 h. Fifteen species belonging to the latter genera were identified and most of them are considered as opportunistic molds of clinical significance.     

Overproduction of threonine by Saccharomyces cerevisiae mutants resistant to hydroxynorvaline.

In this work, we isolated and characterized mutants that overproduce threonine from Saccharomyces cerevisiae. The mutants were selected for resistance to the threonine analog alpha-amino-beta-hydroxynorvalerate (hydroxynorvaline), and, of these, the ones able to excrete threonine to the medium were chosen. The mutant strains produce between 15 and 30 times more threonine than the wild type does, and, to a lesser degree, they also accumulate isoleucine. Genetic and biochemical studies have revealed that the threonine overproduction is, in all cases studied, associated with the presence in the strain of a HOM3 allele coding for a mutant aspartate kinase that is totally or partially insensitive to feedback inhibition by threonine. This enzyme seems, therefore, to be crucial in the regulation of threonine biosynthesis in S. cerevisiae. The results obtained suggest that this strategy could be efficiently applied to the isolation of threonine-overproducing strains of yeasts other than S. cerevisiae, even those used industrially.     

Analysis of Immunoprecipitated Surface Glycoproteins in Measles Virions and in Membranes of Infected Cells

Measles viral envelope proteins were immune precipitated from membranes of infected cells and from purified virus and analyzed by polyacrylamide gel electrophoresis. Under reducing conditions, specific precipitates contained two major polypeptide bands, designated virus glycopeptides 1 and 2 (VGP-1 and VGP-2). Both polypeptides appeared to be glycosylated, as indicated by their incorporation of [¹⁴C]glucosamine in infected cells. VGP-2 appeared as a single band in specific precipitates of infected cells and as a double band in precipitates of purified virus. Trypsin treatment of infected cells showed that reduced VGP-2 may be composed of two unrelated polypeptides. One may be F₁, which is unglycosylated, and the other may correspond to the proteolytic cleavage product of VGP-1, which is glycosylated. The relation of VGP-1 and VGP-2 to smaller surface antigens (X and Y) obtained by tryptic treatment of infected cells remains to be elucidated. In cells taken at various times postinfection and analyzed for viral membrane proteins, VGP-1 was detected at all times, indicating that the input virus VGP-1 was inserted into the cell and could not be differentiated from newly synthesized VGP-1. VGP-2 was not detectable before 24 h postinfection. In precipitates of cells 4 h postinfection and of infected cells incubated at pH 5.8, an additional polypeptide band migrated immediately ahead of VGP-1. We conclude that VGP-2 (molecular weight, 42,000) possibly consists of two components, one of which is the tryptic cleavage product of VGP-1 and the other of which is the unglycosylated polypeptide, F₁.     

Enhancing the power of two choices load balancing algorithm using round robin policy

Cluster Computing - This paper proposes a new version of the power of two choices, SQ(d), load balancing algorithm. This new algorithm improves the performance of the classical model based on the...     

Low Child Survival Index in a Multi-Dimensionally Poor Amerindian Population in Venezuela

Background

Warao Amerindians, who inhabit the Orinoco Delta, are the second largest indigenous group in Venezuela.  High Warao general mortality rates were mentioned in a limited study 21 years ago. However, there have been no comprehensive studies addressing child survival across the entire population.

Objectives

To determine the Child Survival-Index (CSI) (ratio: still-living children/total-live births) in the Warao population, the principal causes of childhood death and the socio-demographic factors associated with childhood deaths.

Methods

We conducted a cross-sectional epidemiological survey of 688 women from 97 communities in 7 different subregions of the Orinoco Delta. Data collected included socio-demographic characteristics and the reproductive history of each woman surveyed. The multidimensional poverty index (MPI) was used to classify the households as deprived across the three dimensions of the Human Development Index. Multivariable linear regression and Generalized Linear Model Procedures were used to identify socioeconomic and environmental characteristics statistically associated with the CSI.

Findings

The average CSI was 73.8% ±26. The two most common causes of death were gastroenteritis/diarrhea (63%) and acute respiratory tract Infection/pneumonia (18%).  Deaths in children under five years accounted for 97.3% of childhood deaths, with 54% occurring in the neonatal period or first year of life.  Most of the women (95.5%) were classified as multidimensionally poor.  The general MPI in the sample was 0.56.   CSI was negatively correlated with MPI, maternal age, residence in a traditional dwelling and profession of the head of household other than nurse or teacher.

Conclusions

The Warao have a low CSI which is correlated with MPI and maternal age.  Infectious diseases are responsible for 85% of childhood deaths.  The low socioeconomic development, lack of infrastructure and geographic and cultural isolation suggest that an integrated approach is urgently needed to improve the child survival and overall health of the Warao Amerindians.      

Effect of Bauhinia forficata extract in diabetic pregnant rats: maternal repercussions.

Bauhinia forficata, commonly known as "paw-of-cow", is widely used in Brazil folk medicine for the treatment of Diabetes mellitus. The purposes of present study were to determine the repercussions of diabetes on the defense system against oxidative stress in pregnant female rats and to characterize the influence of the treatment with Bauhinia forficata extract on the antioxidant system, glycemic control, hepatic glycogen, cholesterol, triglycerides, total proteins and lipids. Virgin female Wistar rats were injected with 40 mg/kg streptozotocin (STZ) before mating. Oral administration of an aqueous extract of Bauhinia forficata leaves was given to non-diabetic and diabetic pregnant rats in 3 doses: 500 mg/kg from 0 to 4th day of pregnancy, 600 mg/kg from 5th to 14th day and 1000 mg/kg from 15th to 20th day. All the females were killed on the day 21 of pregnancy. A maternal blood sample was collected by venous puncture and the maternal liver was removed for biochemical measurement. The diabetic pregnant rats presented hyperglycemia, hyperlipemia, hypertriglyceridemia, hypercholesterolemia, hyperuricemia, decreased determinations of reduced glutathione (GSH) and superoxide dismutase (SOD). Treatment with B. forficata extract did not interfere in the albumin, total protein and lipid, triglyceride, cholesterol and SOD determinations. Increased hepatic glycogen, decreased uric acid concentration and increased GSH activity was observed. This last fact suggests that the plant may have some action on antioxidant defense system. However, the demonstration of the active component present in B. forficata responsible for its antioxidant effect and the increase in hepatic glycogen deserve further investigation.