<Emphasis Type="Italic">Brief Communication</Emphasis>: Does Integration to the Market Threaten Agricultural Diversity? Panel and Cross-Sectional Data From a Horticultural-Foraging Society in the Bolivian Amazon

Trade theory predicts that the expansion of markets induces households to specialize and intensify production. We use plot-level data (n = 64) from a panel study of 2 village and cross-sectional data from 511 households in 59 villages of Tsimane Amerindians (Bolivia) to test the predictions. Results of bivariate analyses using both data sets suggest that as households integrate into the market economy they: (1) deforest more, (2) expand the area under rice cultivation, the principal cash crop, (3) sell more rice, and (4) intensify production by replanting more and by replanting newly cleared plots with maize, another cash crop. Results mesh with predictions about production specialization and intensification of trade theory. The analysis also produced results running counter to predictions from trade theory. For example, households and villages more integrated into the market planted more cassava and rice varieties, intercropped more, and put more crops in new fields than more autarkic households. Although the expansion of markets induces specialization and intensification in selected cash crops, it does not erase completely agricultural diversity. We hypothesize that despite the expansion of markets, households retain agricultural diversity because the market does not yet provide modern forms of self-insurance or well-functioning labor, credit, and product markets that would allow households to protect food consumption when faced with shocks. Without better insurance mechanisms, some agricultural diversity might still allow households to smooth consumption.     

Why do mothers favor girls and fathers, boys?

Growing evidence suggests mothers invest more in girls than boys and fathers more in boys than girls. We develop a hypothesis that predicts preference for girls by the parent facing more resource constraints and preference for boys by the parent facing less constraint. We test the hypothesis with panel data from the Tsimane’, a foraging-farming society in the Bolivian Amazon. Tsimane’ mothers face more resource constraints than fathers. As predicted, mother’s wealth protected girl’s BMI, but father’s wealth had weak effects on boy’s BMI. Numerous tests yielded robust results, including those that controlled for fixed effects of child and household.     

Medium-term outcomes of 78,808 patients after heart valve surgery in a middle-income country: a nationwide population-based study

Background

Heart valve surgery outcomes are unknown in middle-income countries and thus cannot be used in health system decision making processes. This study estimated in-hospital mortality and medium and long-term survival.

Methods

This was a retrospective study of 78,806 patients who underwent heart valve surgery between 2001 and 2007 in Brazil. Two national databases were used, the Hospital Information System and the Mortality Information System. Kaplan-Meier survival analysis and log-rank tests were performed. Maximum and median follow-up was 7.7 and 2.8 years, respectively (0.002–7.707).

Results

Valve replacement accounted for 69.1% of procedures performed. Mitral stenosis, the most common valve injury, represented 38.9% of the total. In 94.7% of mitral stenosis patients, aetiology was rheumatic heart disease. In-hospital mortality was 7.6% and was higher for women, for patients who had undergone concomitant coronary artery bypass grafting (CABG) and for the elderly. Overall survival was 69.9% at the end of follow-up. Survival was worst among elderly, male and concomitant CABG patients (P<0.001).

Conclusions

Rheumatic heart disease is still a major public health problem in Brazil. In-hospital mortality and global survival rates of patients who have undergone heart valve surgery were less satisfactory than those reported in high-income countries. The findings of this study can contribute to guiding decision making processes in middle-income countries similar to Brazil and others concerned with improving the quality of care.

     

Silencing of the tomato Sugar Partitioning Affecting protein (SPA) modifies sink strength through a shift in leaf sugar metabolism

Limitations in our understanding about the mechanisms that underlie source‐sink assimilate partitioning are increasingly becoming a major hurdle for crop yield enhancement via metabolic engineering. By means of a comprehensive approach, this work reports the functional characterization of a DnaJ chaperone related‐protein (named as SPA; sugar partition‐affecting) that is involved in assimilate partitioning in tomato plants. SPA protein was found to be targeted to the chloroplast thylakoid membranes. SPA‐RNAi tomato plants produced more and heavier fruits compared with controls, thus resulting in a considerable increment in harvest index. The transgenic plants also displayed increased pigment levels and reduced sucrose, glucose and fructose contents in leaves. Detailed metabolic and enzymatic activities analyses showed that sugar phosphate intermediates were increased while the activity of phosphoglucomutase, sugar kinases and invertases was reduced in the photosynthetic organs of the silenced plants. These changes would be anticipated to promote carbon export from foliar tissues. The combined results suggested that the tomato SPA protein plays an important role in plastid metabolism and mediates the source‐sink relationships by affecting the rate of carbon translocation to fruits.     

Lipidomic profile as a noninvasive tool to predict endometrial receptivity

For the present study we asked whether the endometrial fluid lipidomic may be a useful approach to predict endometrial receptivity in freeze‐all cycles. For this case‐control study, endometrial fluid samples were collected from 41 patients undergoing freeze‐all cycles. Samples were split depending on the pregnancy outcome: positive group (n = 24) and negative group (n = 17). Data were acquired by the matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS‐DA) were applied. A list of potential biomarker ion ratios was obtained and the values were used to build a receiver operating characteristic (ROC) curve to predict pregnancy success. The lipid categories were attributed by LIPID MAPS database. Ion ratios were established according to their correlations and used for the analysis. The PCA showed a tendency of separation between the studied groups, whereas the PLS‐DA was able to clearly distinguish them. Fifteen ratios (13 hyper‐represented in the negative and two hyper‐represented in the positive group) were selected according to their importance for model prediction. These ratios were used to build the ROC curve, which presented an area under curve of 84.0% (95%CI: 69.2–97.4%; p = 0.009). These findings suggest that lipidomic profiling of endometrial fluid may be a valuable tool for identifying the time interval comprising the window of implantation.     

Infectious salmon anaemia virus (ISAV) isolated from the ISA disease outbreaks in Chile diverged from ISAV isolates from Norway around 1996 and was disseminated around 2005, based on surface glycoprotein gene sequences

Background

All viruses in the family Bunyaviridae possess a tripartite genome, consisting of a small, a medium, and a large RNA segment. Bunyaviruses therefore possess considerable evolutionary potential, attributable to both intramolecular changes and to genome segment reassortment. Hantaviruses (family Bunyaviridae, genus Hantavirus) are known to cause human hemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. The primary reservoir host of Sin Nombre virus is the deer mouse (Peromyscus maniculatus), which is widely distributed in North America. We investigated the prevalence of intramolecular changes and of genomic reassortment among Sin Nombre viruses detected in deer mice in three western states.

Methods

Portions of the Sin Nombre virus small (S) and medium (M) RNA segments were amplified by RT-PCR from kidney, lung, liver and spleen of seropositive peromyscine rodents, principally deer mice, collected in Colorado, New Mexico and Montana from 1995 to 2007. Both a 142 nucleotide (nt) amplicon of the M segment, encoding a portion of the G2 transmembrane glycoprotein, and a 751 nt amplicon of the S segment, encoding part of the nucleocapsid protein, were cloned and sequenced from 19 deer mice and from one brush mouse (P. boylii), S RNA but not M RNA from one deer mouse, and M RNA but not S RNA from another deer mouse.

Results

Two of 20 viruses were found to be reassortants. Within virus sequences from different rodents, the average rate of synonymous substitutions among all pair-wise comparisons (π_s) was 0.378 in the M segment and 0.312 in the S segment sequences. The replacement substitution rate (π_a) was 7.0 × 10^-4 in the M segment and 17.3 × 10^-4 in the S segment sequences. The low π_a relative to π_s suggests strong purifying selection and this was confirmed by a Fu and Li analysis. The absolute rate of molecular evolution of the M segment was 6.76 × 10^-3 substitutions/site/year. The absolute age of the M segment tree was estimated to be 37 years. In the S segment the rate of molecular evolution was 1.93 × 10^-3 substitutions/site/year and the absolute age of the tree was 106 years. Assuming that mice were infected with a single Sin Nombre virus genotype, phylogenetic analyses revealed that 10% (2/20) of viruses were reassortants, similar to the 14% (6/43) found in a previous report.

Conclusion

Age estimates from both segments suggest that Sin Nombre virus has evolved within the past 37–106 years. The rates of evolutionary changes reported here suggest that Sin Nombre virus M and S segment reassortment occurs frequently in nature.     

A requirement for an unconjugated pteridine for the growth of Paramecium aurelia

The ciliated protozoan Paramecium aurelia requires exceptionally high levels (microgram amounts) of folic acid for optimal growth when cultured in a compex synthetic medium. This requirement may be replaced by nanogram quantities of the vitamin provided the unconjugated pteridine biopterin is present in the medium. Both folic acid and biopterin are essential for optimal growth. Evidence has been obtained that the growth-promoting effect of abnormally high concentrations of folic acid may be due to the ability of the protozoan to convert small quantities of the vitamin into biopterin or other nutritionally active pteridines.     

Impact of Extraction Parameters on the Recovery of Lipolytic Activity from Fermented Babassu Cake

Enzyme extraction from solid matrix is as important step in solid-state fermentation to obtain soluble enzymes for further immobilization and application in biocatalysis. A method for the recovery of a pool of lipases from Penicillium simplicissimum produced by solid-state fermentation was developed. For lipase recovery different extraction solution was used and phosphate buffer containing Tween 80 and NaCl showed the best results, yielding lipase activity of 85.7 U/g and 65.7 U/g, respectively. The parameters with great impacts on enzyme extraction detected by the Plackett-Burman analysis were studied by Central Composite Rotatable experimental designs where a quadratic model was built showing maximum predicted lipase activity (160 U/g) at 25°C, Tween 80 0.5% (w/v), pH 8.0 and extraction solution 7 mL/g, maintaining constant buffer molarity of 0.1 M and 200 rpm. After the optimization process a 2.5 fold increase in lipase activity in the crude extract was obtained, comparing the intial value (64 U/g) with the experimental design (160 U/g), thus improving the overall productivity of the process.