Comparative analysis of SHALSTAB and SINMAP for landslide susceptibility mapping in the Cunha River basin,southern Brazil

Purpose

The Shallow Landsliding Stability Model (SHALSTAB) and Stability Index Mapping (SINMAP) models have been applied to various landslide management and research studies. Both models combine a hydrological model with an infinite slope stability model for predicting landslide occurrence. The objectives of the present study were to apply these two models to the Cunha River basin, Santa Catarina State, southern Brazil, where many landslides occurred in November 2008, and perform a comparative analysis of their results.

Materials and methods

Soil samples were collected to determine the input parameters. The models were calibrated with a landslide scar inventory, and rainfall data were obtained from three rain gauges. A comparison of their results obtained from the models was undertaken with the success and error index.

Results and discussion

Based on the maps of stability and instability areas for the study basin, the models performed well. Since the initial equations of both models are not particularly different, their results are similar. Locations with steep slopes, as well as areas with concave relief that tend to have larger contribution areas and moisture, have lower stability indexes. SHALSTAB classified only ~13 % of the total area of the Cunha River basin as unstable, while SINMAP classified ~30 % as unstable.

Conclusions

The analysis of maps based on the results of the two models shows that if SHALSTAB is correctly calibrated, based on hydrological parameters, its results could be more accurate than SINMAP in the prediction of landslide areas. Although SINMAP showed better calibration of the landslide scars, its classification over the basin results in an overestimation of stability areas. The conclusion is that SHALSTAB is more suitable than SINMAP for the prediction of landslides in the Cunha River basin, Brazil.     

Quinone and Hydroquinone Metabolites from the Ascidians of the Genus Aplidium

Ascidians of the genus Aplidium are recognized as an important source of chemical diversity and bioactive natural products. Among the compounds produced by this genus are non-nitrogenous metabolites, mainly prenylated quinones and hydroquinones. This review discusses the isolation, structural elucidation, and biological activities of quinones, hydroquinones, rossinones, longithorones, longithorols, floresolides, scabellones, conicaquinones, aplidinones, thiaplidiaquinones, and conithiaquinones. A compilation of the ¹³C-NMR spectral data of these compounds is also presented.     

Time for sex: nycthemeral distribution of human sexual behavior

Background  

Nycthemeral (daily) oscillation has been documented in a variety of physiological and behavioral processes. The present study was carried out to evaluate the existence of a nycthemeral rhythm of human sexual behavior and to identify environmental factors responsible for the rhythmic pattern.     

Germination in Optimal Conditions as Effective Strategy to Improve Nutritional and Nutraceutical Value of Underutilized Mexican Blue Maize Seeds

Plant Foods for Human Nutrition - Germination of grains is a bioprocess of emerging interest to improve nutritional and nutraceutical profile of cereals in a natural way. The aim of this work was...     

Varying Nitrogen Concentrations to Optimize Basic Seed Potato Minitubers Production in a Three-Phase Hydroponic System

In hydroponics, nutrient management is the limiting factor to obtaining optimal production, and nitrogen (N) is the key component to consider when optimizing nutrient management in these types of systems. The objective of this study is to evaluate different combinations of N fertilizer concentrations in order to optimize the yield of basic seed potato minitubers in a three-phase hydroponic system. Treatments consisted of five combinations of N concentrations, applied before and after 21 days after plant transplant as follows, respectively: 1) 13 and 13, 2) 13 and 0, 3) 13 and 7.8, 4) 13 and 16, and 5) 13 and 26 mmol L^?1. Propagation was performed by transplanting 3–4 cm potato plantlets cv. Agata from sprouts. There were significant effects of N treatments on all measured variables (root, leaf, stem, and plant dry weight and minituber number and weight). To obtain the maximum minituber number yield, 9.51 minitubers/plant, corresponding to 67 minitubers/m², post 21-day adjusted N concentration was 18.4 mmol/L. Treatment 4 promoted higher basic seed potato minituber yield in a three-phase hydroponic system.     

Chitosan and Kappa-Carrageenan Vaginal Acyclovir Formulations for Prevention of Genital Herpes. In Vitro and Ex Vivo Evaluation

Vaginal formulations for the prevention of sexually transmitted infections are currently gaining importance in drug development. Polysaccharides, such as chitosan and carrageenan, which have good binding capacity with mucosal tissues, are now included in vaginal delivery systems. Marine polymer-based vaginal mucoadhesive solid formulations have been developed for the controlled release of acyclovir, which may prevent the sexual transmission of the herpes simplex virus. Drug release studies were carried out in two media: simulated vaginal fluid and simulated vaginal fluid/simulated seminal fluid mixture. The bioadhesive capacity and permanence time of the bioadhesion, the prepared compacts, and compacted granules were determined ex vivo using bovine vaginal mucosa as substrate. Swelling processes were quantified to confirm the release data. Biocompatibility was evaluated through in vitro cellular toxicity assays, and the results showed that acyclovir and the rest of the materials had no cytotoxicity at the maximum concentration tested. The mixture of hydroxyl-propyl-methyl-cellulose with chitosan- or kappa-carrageenan-originated mucoadhesive systems that presented a complete and sustained release of acyclovir for a period of 8–9 days in both media. Swelling data revealed the formation of optimal mixed chitosan/hydroxyl-propyl-methyl-cellulose gels which could be appropriated for the prevention of sexual transmission of HSV.     

Influence of genotype and environment on the content of 5-n alkylresorcinols,total phenols and on the antiradical activity of whole durum wheat grains

The 5-n-alkylresorcinol (AR) contents of thirty different cultivars of durum wheat grown in two years (2009 and 2010) in two Italian locations were determined and related to the total soluble phenolic content (TPC) and antiradical activity (AA). On average, AR and TPC ranged from 161.3 to 405.8 μg/g (dry matter, DM) and from 19.0 to 192.4 μg/g (DM), respectively. AA (EC₅₀ values) ranged from 70.9 to 289.2 mg of dry whole milled wheat grain (DM). The results showed that the environment (E) and the genotype (G), as well as their interactions (G × E), significantly influenced the phytochemical profiles of the samples. The contribution of G × E to the total variance was much lower than that due to the separate effects (G and E). Principal component analysis identified genotypes that were richer in ARs and more stable across environments. There were significant negative correlations between ARs and TPC (p < 0.05) and between TPC and AA (p < 0.01), but not between ARs and AA. Graphical representation was efficient in summarizing the overall antiradical profiles of the durum wheat grain in each environment.     

Inhibition of Hepatocellular Carcinoma Growth by Ethyl Acetate Extracts of Apulian Brassica oleracea L. and Crithmum maritimum L.

Plant Foods for Human Nutrition - Nowadays, a growing body of evidence supports the view that plants offer an extraordinary opportunity to discover and develop new promising therapeutic strategies...     

Exploring Chemical Diversity of Phorbas Sponges as a Source of Novel Lead Compounds in Drug Discovery

Porifera, commonly referred to as marine sponges, are acknowledged as major producers of marine natural products (MNPs). Sponges of the genus Phorbas have attracted much attention over the years. They are widespread in all continents, and several structurally unique compounds have been identified from this species. Terpenes, mainly sesterterpenoids, are the major secondary metabolites isolated from Phorbas species, even though several alkaloids and steroids have also been reported. Many of these compounds have presented interesting biological activities. Particularly, Phorbas sponges have been demonstrated to be a source of cytotoxic metabolites. In addition, MNPs exhibiting cytostatic, antimicrobial, and anti-inflammatory activities have been isolated and structurally characterized. This review provides an overview of almost 130 secondary metabolites from Phorbas sponges and their biological activities, and it covers the literature since the first study published in 1993 until November 2021, including approximately 60 records. The synthetic routes to the most interesting compounds are briefly outlined.     

Characterization of wastewater generated by Litopenaeus vannamei after being fed experimental diets based on animal protein,vegetable protein and a commercial diet

Phosphorous (P) and nitrogen (N) residuals from Litopenaeus vannamei and N and P retention by L. vannamei were studied at three protein levels and with two protein sources: fish meal with plant protein (AVD) and plant protein with squid meal as an attractant (VD). A protein retention bioassay began with shrimp that were 1.5–2.5 g, and nutrient release bioassays were conducted with shrimp of two sizes (4.5 and 8.5 g). Both bioassays were conducted at: 30 ± 0.5°C, [O₂] > 4 mg L^?1, and 38 UPS. Total P residuals were significantly higher for AVDs than for VDs (P < 0.05), particularly those with a high dietary protein level. The particulate P fraction was the predominant form of P. Total N and inorganic dissolved N, mainly in ammonia form, significantly increased (P < 0.05) with dietary protein level and shrimp size, regardless of the protein source. VDs resulted in significantly greater P retention (P < 0.05) than AVDs, without significantly affecting growth rates or survival. P retention as well as N retention decreased with increasing protein supplementation level, independently of the protein source used (P > 0.05). This study shows that the substitution of fish meal with plant protein (soybean meal and wheat flour) improves P retention in L. vannamei.