Olive crop-yield forecasting based on airborne pollen in a region where the olive groves acreage and crop system changed drastically

Olive trees are one of the most economically important perennial crops in Portugal. During the last decade, the Alentejo olive-growing region has suffered a significantly change in the crop production system, with the regional pollen index (RPI) and olive fruit production registering a significant growth. The aim of this study was to ascertain the utility of this highly variable production and pollen data in crop forecasting modeling. Airborne pollen was sampled using a Cour-type trap from 1999 to 2015. A linear regression model fitted with the regional pollen index as the independent variable showed an accuracy of 87% in estimating olives fruit production in Alentejo. However, the average deviation between observed and modeled production was 32% with half of the tested years presenting deviations between 36 and 66%. The low accuracy of this model is a consequence of the great overall variation and significant upward trend observed in both the production and the RPI dataset that conceal the true association between these variables. In order to overcome this problem, a detrend procedure was applied to both time series to remove the trend observed. The regression model fitted with the fruit production and the RPI detrended data showed a lowest forecasting accuracy of 63% but the average deviation between observed and modeled production decrease to 14% with a maximum deviation value of 33%. This procedure allows focusing the analysis on the production fluctuations related to the biological response of the trees rather than with the changes in the production system.     

Storage conditions do not have detrimental effect on allograft collagen or scaffold performance

Musculoskeletal allografts are a valuable alternative to autograft tissue in orthopaedic surgeries. However, the effects of the allografts’ storage history on the collagen and subsequent allograft scaffold properties are unknown. In this study, we hypothesized that freezing and refrigeration of allografts for 1 week would alter the biologic performance and mechanical properties of the allograft collagen. Allograft collagen was characterized by SDS–PAGE migration pattern, amino acid profile and measured denaturation. Scaffolds made from allograft collagen were evaluated for fibroblast proliferation, platelet activation and scaffold retraction. Collagen gelation kinetics (elastic and inelastic moduli and the viscous-elastic transition point) were also evaluated. Fibroblast proliferation, platelet activation and scaffold retraction results showed only minor, though statistically significant, differences between the storage groups. In addition, there were no significant differences in rheological properties or collagen biochemistry. In conclusion, this study suggests that freezing or refrigeration for 1 week does not appear to have any detrimental effect on the mechanical properties and biologic performance of the collagen within allografts.     

Antimicrobial, antitumor and antileishmania screening of medicinal plants from Guinea-Bissau.

Following an ethnobotanical search carried out in Guinea-Bissau, eighteen extracts derived from sixteen medicinal species were screened for antimicrobial, antitumor and antileishmania activity. Significant antitumor activity was found for Holarrhena floribunda against KB (squamous carcinoma), SK-Mel 28 (melanoma), A 549 (lung carcinoma) and MDA-MB 231 (mamma carcinoma) cell lines, with corresponding IC50 values of 7.9, 9.0, 3.4 and 9.9 micrograms/ml. Khaya senegalensis and Anthostema senegalense exhibited a significant activity against Leishmania donovani with IC50 values of 9.8 and 9.1 micrograms/ml, respectively. Most of the extracts showed week or moderate antibacterial and antifungal activity, with MIC values in the range 0.25-1.0 mg/ml. Active extracts were submitted to bioassay-guided fractionation, and the IC50 and MIC of the active fractions were determined.