Structure-activity relationships of 1,2,3-benzothiadiazoles as synergists for carbaryl against the house fly (Musca domestica)

Fifty six 1,2,3-benzothiadiazoles and related compounds were evaluated as carbaryl synergists against the house fly (Musca domestica). Many of these were excellent synergists, the most active being those containing various combinations of halogen, alkyl, or alkoxy substituents in the 5- and/or 6-positions of the ring.Regression analysis on the data from 14 compounds for which substituents constants were available established that synergistic activity can be satisfactorily described by equations in terms of the hydrophobic bonding constant (π) and the homolytic free radical constant (σ ·).The results with compounds related to the 1,2,3-benzothiadiazoles suggest that synergistic activity is associated primarily with the diazosulfide moiety.     

Canine fetal echocardiography: correlations for the analysis of cardiac dimensions

The aim of this study was to develop regression models for correlation of canine fetal heart development with body size to characterize normal development or suggest cardiac anomalies. Twenty clinically healthy pregnant bitches, either brachycephalic and non-brachycephalic, were examined ultrasonographically. Transabdominal fetal echocardiography was conducted every 4 days from the beginning of cardiac chambers differentiation until parturition. Ten cardiac parameters were measured: length, width and diameter of the heart; heart area; left and right ventricular dimensions; left and right atrial dimensions; and aortic and pulmonary artery diameter. Femoral length, biparietal diameter and abdominal cross-sectional area were also recorded. Regression equations were developed for each parameter of fetal body size, and linear and logarithmic models were compared. The model with the highest correlation coefficient was chosen to produce equations to calculate relative dimensions based on the correlations. Only the left-ventricular chamber differed between the two racial groups. Biparietal diameter was the independent parameter that produced the highest correlation coefficient for the most fetal cardiac dimensions, although good correlations were also observed using femoral length and abdominal cross-sectional area. Heart width and heart diameter were used as surrogates of cardiac development, as these measurements showed the best statistical correlation. Quantitative evaluation of fetal cardiac structures can be used to monitor normal and abnormal cardiac development.     

Characterization of humus-protease complexes extracted from soil

Pyrophosphate (140 mM, pH 7.1) extracts of two arable soils and one pasture soil were ultrafiltrated separating the extracted material into three fractions: A_I with nominal molecular weight (nmw) > 100 kD, A_II with nmw between 10 kD and 100 kD and R with nmw < 10 kD. Protease activity was determined in the fractions by using three different substrates: N-benzoyl-l-argininamide (BAA), specific for trypsin; N-benzyloxy-carbonyl-l-phenylalanyl l-leucine (ZPL), specific for carboxypeptidases; and casein, essentially a non-specific substrate. The derivative fractions were also analysed for their amino acid N and humic (HA) and fulvic (FA) acid contents. The organic matter of extracts and derivative fractions obtained from the pasture soil was analysed by isoelectric focusing (IEF) and that of fractions analysed by pyrolysis gas chromatography (Py-GC). Activities of the extract were monitored for their thermal stability and those of the extract and derivative fractions for their optimal pH.Due to the mechanical disintegrating action of sodium pyrophosphate over the humic substances during the fractionation process the amount of total organic C and FA in the fractions was ranked as R > A_II > A_I. The lowest amino acid N/organic C was found in the R fraction, whereas A_II fraction was rich in humic acids, carbohydrates and amino acid N and A_I fraction showed the lowest carbohydrate content. At least 70% of the total BAA- and ZPL-hydrolysing activity was associated to particles with nmw higher than 10 kD and at least 30% of these activities were present in particles with nmw higher 100 kD. Casein-hydrolysing activity was quite evenly distributed among the three fractions (A_I, A_II and R). The extracted protease-organic complexes were resistant to thermal denaturation and some of them showed optimal activity at pH values higher than 10 as a result of the polyanionic characteristics of the humic material surrounding enzyme molecules and of the presence of alkaline protease. Comparison of data obtained in Py-GC analyses and in protease activity suggests that BAA-hydrolysing activity was associated to a highly condensed humic matter and ZPL-hydrolysing activity to less resistant humic substances, while at least some of the extracted casein-hydrolysing activity was present as glyco-proteins not associated to humus. BAA-hydrolysing activity was probably inhibited by fresh organic matter of carbohydrate origin whereas lignin derived organic matter probably inhibited ZPL- and casein-hydrolysing activity.     

Induced expression of selected plant defence related genes in pot azalea, <Emphasis Type="Italic">Rhododendron simsii</Emphasis> hybrid

A set of putative marker genes to study plant defense responses against Polyphagotarsonemus latus, a key pest in the production of Rhododendron simsii hybrids, was selected and validated. Genes belonged to the biosynthetic pathway of phytohormones jasmonic acid (JA) (RsLOX, RsAOS, RsAOC, RsOPR3 and RsJMT) and salicylic acid (SA) (RsPAL and RsICS). Furthermore, RsPPO, a putative marker gene for oxidative stress response was successfully cloned from R. simsii. A CTAB-based extraction protocol was optimized to assure excellent RNA quality for subsequent RT-qPCR analysis. The RT-qPCR protocol was extensively tested and RsRG7 and RsRG14 were selected as reference genes from a geNorm pilot study. Validation of the marker genes was done after application with elicitors [methyl jasmonate (MeJA), coronatine, β-aminobutyric acid and acibenzolar-Smethyl] or wounding. Both 100 μM MeJA and 0.1 μM coronatine had a significant effect on the expression of all marker genes. Foliar application of MeJA on the shoots resulted in a significantly earlier response when compared to root application and subsequent sampling of the shoots. Expression patterns after MeJA treatment were generally the same in six R. simsii genotypes: ‘Nordlicht’, ‘Elien’, ‘Aiko Pink’, ‘Michelle Marie’, ‘Mevrouw Gerard Kint’ and ‘Sachsenstern’. Wounding resulted in the same expression patterns as MeJA treatment except for RsJMT. None of the genotypes showed a significant induction of the latter gene 6 h upon wounding. Findings of these experiments indicated that the tolerant genotype ‘Elien’ has low basal expression levels of RsPPO. This might be the first step towards the breeding of mite-tolerant genotypes.     

Potential Anti-Aging Substances Derived from Seaweeds

Aging is a major risk factor for many chronic diseases, such as cancer, cardiovascular disease, and diabetes. The exact mechanisms underlying the aging process are not fully elucidated. However, a growing body of evidence suggests that several pathways, such as sirtuin, AMP-activated protein kinase, insulin-like growth factor, autophagy, and nuclear factor erythroid 2-related factor 2 play critical roles in regulating aging. Furthermore, genetic or dietary interventions of these pathways can extend lifespan by delaying the aging process. Seaweeds are a food source rich in many nutrients, including fibers, polyunsaturated fatty acids, vitamins, minerals, and other bioactive compounds. The health benefits of seaweeds include, but are not limited to, antioxidant, anti-inflammatory, and anti-obese activities. Interestingly, a body of studies shows that some seaweed-derived extracts or isolated compounds, can modulate these aging-regulating pathways or even extend lifespans of various animal models. However, few such studies have been conducted on higher animals or even humans. In this review, we focused on potential anti-aging bioactive substances in seaweeds that have been studied in cells and animals mainly based on their anti-aging cellular and molecular mechanisms.     

Using graph theory to analyse and assess changes in Mediterranean woodland connectivity

Landscape Ecology - The Portuguese montado is an agro-silvopastoral system, similar to the Spanish dehesa, known for its cultural, economic and ecological value. Despite its importance, contrasting...     

First attempts towards the restoration of gorgonian populations on the Mediterranean continental shelf

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