Methyl paraben as a sex pheromone in canine urine – is the question still open?

The literature concerning the issue of canine sex pheromones includes reports presenting completely conflicting opinions about the chemical composition of the canine urine in the context of semiochemical communication. At present, the predominant report cited by many different authors is the article published in Science in 1979 by Goodwin at al., presenting methyl p-hydroxybenzoate (methyl paraben) as the main canine sex pheromone. While it has been proved that pure methyl paraben lacks semiochemical activity as do commercially available products containing this substance (Eau D’Estrus, Synbiotics, USA), in view of the conflicting published reports the aim of this study was to revaluate using modern techniques the presence of methyl p-hydroxybenzoate in canine urine during different phases of the ovarian cycle. Ten female dogs of different breeds were used. Urine samples from bitches collected during various stages of the ovarian cycle were examined with using the SPME and GC/MS methods. Methyl paraben was not detected in any of the samples. In conclusion, because of the lack of methyl-p-hydroxybenzoate in the samples examined, the present study confirmed negative opinions on the possibility of this substance playing a crucial role in semiochemical communication during reproduction in dogs (Canis familiaris)

Impact of spatial position of detonator in bulk emulsion explosive charge on detonation efficiency

Materiały wybuchowe emulsyjne należą do grupy materiałów stosunkowo bezpiecznych, co związane jest z ich niewielką wrażliwością na działanie czynników zewnętrznych. Aby zapewnić optymalne warunki inicjacji ładunków MW, konieczne jest doprowadzenie odpowiednio silnego impulsu energetycznego. W celu zwiększenia energii początkowej wybuchu, ładunki inicjuje się przy pomocy zapalnika i pobudzacza. Jednak w przypadku urabiania skał miękkich, takich jak piaskowce, materiał wybuchowy inicjowany jest najczęściej przy użyciu zapalników. Biorąc pod uwagę wymiary zapalników, prawdopodobnym jest, że w trakcie łączenia obwodu strzałowego może dochodzić do zmiany ich lokalizacji w otworze strzałowym. Taka sytuacja może negatywnie wpływać na efekt końcowy robót strzałowych. W ramach niniejszego opracowania przeanalizowano wpływ przestrzennego położenia zapalnika w ładunku MWE luzem na skuteczność detonacji.Emulsion explosives belong to a group of relatively safe materials. It is related to their low sensitivity to external impulses. To ensure optimum conditions for initiating process, a sufficiently strong energy impulse must be applied. In order to increase the initial energy of the explosion, charges are initiated by means of a detonator and booster. However, in case of detonation in soft rocks such as sandstones, the explosive is most often initiated using detonators only. In the light of the dimensions of the detonators, it is likely that detonators may change their location in the blast hole during the loading process. It may adversely affect the final effect of blasting works. The aim of this paper is to analyse the effect of the position of the igniter within the bulk emulsion explosive charge on the detonation efficiency

W poszukiwaniu biopestycydów: wpływ olejku eterycznego z kminku Carum carvi i jego głównych składników na zachowanie mszycy brzoskwiniowej Myzus persicae podczas penetracji roślin

The application of caraway essential oil and its main components, carvone and limonene, to plant surface caused significant changes in aphid probing at the level of non-vascular tissues as well as sieve elements. On treated plants, probes were short and non-probing intervals were long, phloem phase was short and sustained sap ingestion periods occurred sporadically. The deterrent activity of caraway oil is determined mainly by the content of carvone that has the most significant impact on aphid probing behavior. The impediment of aphid probing at the pre-ingestive (pre-phloem) and/or ingestive (phloem) phases revealed the passage of compounds through the plant surface and distribution within tissues in a systemic way

The Influence of Drying Method on Volatile Composition and Sensory Profile of Boletus edulis

The objective of this study was to evaluate the influence of different drying methods on aroma and sensory profile of Boletus edulis (cepe). The drying methods tested were convective drying (CD), freeze-drying (FD), vacuum microwave drying (VMD), and a combination of convective predrying and vacuum microwave finish-drying (CPD-VMFD). Fresh and dried cepe volatiles, analyzed by SPME and GC-MS, showed the presence of 53 volatile compounds, most of them present in all dried samples but with quantitative variation. The major volatile compounds in fresh and dried cepe were 1-octen-3-ol (3405 µg 100 g−1·db), 3-octanone (429 µg 100 g−1·db), and hexanal (355 µg 100 g−1·db). The results showed that drying of cepe mushrooms caused major losses of aroma compounds; however, the highest content of volatile compounds and the highest intensity of most of the key positive sensory attributes were found in samples after (i) CD at 80°C (3763 µg 100 g−1·db), (ii) CD at 70°C (3478 µg 100 g−1·db), and (iii) CPD at 60°C and VMFD at 480/240 W (2897 µg 100 g−1·db)

Chromenes, chromanones and alkyl substituted phenols as antifeedants to storage pests and aphids

The aim of the work was to study the feeding deterrent activity of precocenes, their synthetic analogues, and some related compunds to storage pests: Sitophilus granarius L., Tribolium confusum Duv., Trogoderma granarium Ev., and aphids: Myzus persicae (Sulz.). Among all tested compounds precocenes I and II exhibited the best feeding deterrent activity against all tested insects. 4-Chromanols (16, 17 and 18), alcohols 19, 20 and 3-chromanone ( 15) showed high deterrence towards the larvae of T. confusum. The best antifeedant activity towards the adults of both T. confusum and S. granarius was observed for substituted phenols with methoxy group at benzene ring. The biological tests carried out on aphids showed that the presence of methoxy group in the molecule was a crucial structural factor for the appearance of antifeedant activity against these insects.Prekoceny i ich analogi oraz niektóre związki fenolowe poddano testom biologicznym na aktywność deterentną. Badania przeprowadzono na trzech szkodnikach magazynów zbożowych: larwach skórka zbożowego (Trogoderma granarium Ev.), larwach i chrząszczach trojszyka ulca (Tribolium confusum Duv.), chrząszczach wołka zbożowego (Sitophilus granarius L.) oraz na mszycy brzoskwiniowo-ziemniaczanej (Myzus persicae Sulz.). Testy wykazały, że najbardziej aktywnymi antyfidantami w stosunku do larw trojszyka ulca są 4-chromanole (16, 17 i 18), alkohole 19 i 20 oraz 3-chromanon (15). Fenole z grupami metoksylowymi wykazały wysoką aktywność zarówno w stosunku do larw, jak i chrząszczy trojszyka ulca. Połączenia te okazały się również, jako jedyne z testowanych, aktywne w stosunku do mszyc. Wskazuje to na grupy metoksylowe jako elementy strukturalne decydujące o aktywności deterentnej badanych połączeń fenolowych

The Effect of Trichoderma spp. on the Composition of Volatile Secondary Metabolites and Biometric Parameters of Coriander (Coriandrum sativum L.)

The aim of this work was to investigate the influence of Trichoderma spp. on volatile secondary metabolites and biometric parameters obtained from coriander (Coriandrum sativum L.). The fruits of coriander treated with liquid suspension spores of T. harzianum strain T22 and of T. asperellum strain B35 increased the yield of essential oil (by ∼36%); however, it was unaffected in its composition. Moreover, Trichoderma spp. influenced the yield and increased the number of seeds of coriander by ∼60%. Inoculation seeds with T. asperelleum strain B35 caused about 2-fold increase in the biomass of the aerial parts of coriander. There was also an increased root colonization by the fungus Trichoderma spp., limiting the number of phytopathogenic fungi from genus Fusarium observed