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1.
Exp Appl Acarol ; 92(2): 263-273, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38351234

ABSTRACT

The aim of this research was to investigate the larvicidal and repellent effects of essential oils (EOs) obtained from two Lamiaceae plant species, Origanum minutiflorum O. Schwarz & P.H. Davis and Dorystoechas hastata Boiss. & Heldr. ex Bentham, both endemic to Turkey, on Rhipicephalus sanguineus s.l. Latreille (Acari: Ixodidae). The study also introduces a new test method that can be used to assess the repellent effects against ticks. Both plant EOs exhibited the highest larvicidal activity against brown dog tick larvae after 24 h and LC50 and LC90 values were determined as 0.101% and 0.125% for O. minutiflorum essential oil and 0.937% and 2.1% for D. hastata essential oil, respectively. In this study, we have described a detailed protocol for a novel larval repellent activity test (LRAT) for essential oils and extracts, using simple equipment. The advantages and limitations of LRAT, when compared to other tests commonly used to determine repellent effect against ticks, are also included in this study. The LRAT was developed with modifications of the larval immersion test (LIT) and proves to be a highly efficient and easily observable method. It can be used to test any active substance that may be toxic to humans and animals. According to the LRAT, at the end of 3 h, O. minutiflorum essential oil showed a high repellent effect, varying between 84.14% and 100% at 1% concentration. This result was not statistically different from the DEET, the positive control. When comparing the larvicidal and repellent activities, O. minutiflorum essential oil was found to be more effective than D. hastata essential oil.


Subject(s)
Acaricides , Insect Repellents , Ixodidae , Oils, Volatile , Rhipicephalus sanguineus , Rhipicephalus , Dogs , Humans , Animals , Oils, Volatile/pharmacology , Larva , Insect Repellents/pharmacology , Acaricides/pharmacology
2.
Med Vet Entomol ; 38(2): 172-178, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38124363

ABSTRACT

Cockroaches, widespread pests found in metropolitan areas, are known as vectors of various disease agents, including viruses, fungi and antibiotic-resistant bacteria, as well as causing allergies in humans. Insect growth regulators have been used in pest management for several decades. These insecticides disrupt insect development and reproduction. Chitin synthesis inhibitors interfere with chitin biosynthesis in insects, causing abortive moulting and mortality, as well as inhibiting egg fertility, and larval hatching in insects. In this research, we evaluated the various effects of diflubenzuron, a chitin synthesis inhibitor, on synthetic pyrethroid-resistant German cockroach (Blattella germanica L. Blattodea: Ectobiidae), including ootheca production, oothecal viability, ootheca incubation time, the number of nymphs emerging from the ootheca and survivorship of nymphs. The cockroaches were fed diets that contained diflubenzuron, which was added to solid bait (impregnated fish food) and ingestible aqueous bait (impregnated cotton). Three concentrations (0.5%, 1% and 2%) were used in the experiments. As a result, diflubenzuron treatment led to ootheca production ranging from 60% to 100%; statistically, no difference was found between the treatment and the control groups. The number of nymphs emerging from the first and second ootheca was reduced by 40%-100% in the diflubenzuron-treated groups compared with the control. Nymphs exposed to diflubenzuron-impregnated solid bait and ingestible aqueous bait experienced mortality exceeding 92.1% and 66.27% within 15 days, respectively. In conclusion, diflubenzuron is a potential insecticide for use in cockroach baits to control B. germanica, as it caused high nymphal and embryonic mortality in the synthetic pyrethroid-resistant population and decreased the number of nymphs emerging from the ootheca.


Subject(s)
Blattellidae , Diflubenzuron , Insecticide Resistance , Insecticides , Nymph , Pyrethrins , Animals , Diflubenzuron/pharmacology , Blattellidae/drug effects , Nymph/growth & development , Nymph/drug effects , Pyrethrins/pharmacology , Insecticides/pharmacology , Diet/veterinary
3.
Molecules ; 28(23)2023 Nov 21.
Article in English | MEDLINE | ID: mdl-38067421

ABSTRACT

This study investigated the potential acaricidal and repellent effects of tar obtained from the Lebanon cedar (Cedrus libani A. Rich.) against the brown dog tick species Rhipicephalus sanguineus sensu lato Latreille (Acari: Ixodidae). The goal was to find an alternative, safe, and effective way to eliminate ticks. Tar is traditionally extracted from cedar trees in the Antalya region of Türkiye. The composition of the tar is primarily characterized by a diverse mixture of terpenes, with ß-himachalene (29.16%), α-atlantone (28.7%), ar-turmerone (8.82%), longifolene-(V4) (6.66%), α-himachalene (5.28%), and ß-turmerone (5.12%) emerging as the predominant constituents. The toxic effects of tar on tick larvae were studied through larval immersion tests (LIT), and its repellent activity was evaluated using a new larval repellent activity test (LRAT). The results revealed significant acaricidal effects, with mortality rates of 77.7% and 82.2% for the Konyaalti and Kepez strains of the brown dog tick, respectively, in response to a 1% concentration of tar. LC50 and LC90 values were determined as 0.47% and 1.52% for the Kepez strain and 0.58% and 1.63% for the Konyaalti strain, respectively. When comparing the repellent effect of tar to the widely used synthetic repellent DEET, repellency rates of up to 100% were observed. As a result, this study establishes, for the first time, the larvicidal and repellent effects of C. libani tar on ticks.


Subject(s)
Acaricides , Insect Repellents , Ixodidae , Rhipicephalus sanguineus , Rhipicephalus , Dogs , Animals , Rhipicephalus sanguineus/physiology , Cedrus , Insect Repellents/pharmacology , Acaricides/pharmacology
4.
Front Hum Neurosci ; 16: 861517, 2022.
Article in English | MEDLINE | ID: mdl-35634201

ABSTRACT

In the cognitive neuroscience of consciousness, participants have commonly been instructed to report their conscious content. This, it was claimed, risks confounding the neural correlates of consciousness (NCC) with their preconditions, i.e., allocation of attention, and consequences, i.e., metacognitive reflection. Recently, the field has therefore been shifting towards no-report paradigms. No-report paradigms draw their validity from a direct comparison with no-report conditions. We analyze several examples of such comparisons and identify alternative interpretations of their results and/or methodological issues in all cases. These go beyond the previous criticism that just removing the report is insufficient, because it does not prevent metacognitive reflection. The conscious mind is fickle. Without having much to do, it will turn inward and switch, or timeshare, between the stimuli on display and daydreaming or mind-wandering. Thus, rather than the NCC, no-report paradigms might be addressing the neural correlates of conscious disengagement. This observation reaffirms the conclusion that no-report paradigms are no less problematic than report paradigms.

5.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 6): o728-9, 2014 Jun 01.
Article in English | MEDLINE | ID: mdl-24940296

ABSTRACT

In the title compound, C18H19NO5S, the five-membered isoxazolidine ring is in a half-chair conformation, and the phenyl rings are oriented at a dihedral angle of 66.53 (3)°. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional supra-molecular structure. A weak C-H⋯π inter-action is also observed between adjacent mol-ecules.

6.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 4): o492-3, 2014 Apr 01.
Article in English | MEDLINE | ID: mdl-24826183

ABSTRACT

The asymmetric unit of the title compound, C26H28O6·2CH3OH, contains two independent methyl 6-O-trityl-α-d-gluco-pyran-oside mol-ecules and four methanol solvent mol-ecules. The rings of two methyl α-d-gluco-pyran-oside adopt chair conformations. In the crystal, extensive intra- and inter-molecular O-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional supra-molecular architecture.

7.
Article in English | MEDLINE | ID: mdl-24427076

ABSTRACT

In the title compound, C10H17IO5, the six-membered tetra-hydro-pyran ring and the five-membered 1,3-dioxolane ring adopt sofa and envelope conformations, respectively. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into layers nearly parallel to the bc plane.

8.
Article in English | MEDLINE | ID: mdl-24427098

ABSTRACT

In the title compound, C14H14INO4, the di-hydro-pyridine ring adopts a twist conformation. In the crystal, pairs of N-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into inversion R 2 (2)(10) and R 2 (2)(18) dimers, forming infinite double chains running along the c axis.

9.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 3): o606, 2012 Mar 01.
Article in English | MEDLINE | ID: mdl-22412519

ABSTRACT

In the title compound, C(16)H(17)NO(5), the dihydro-pyridine ring adopts a sofa conformation. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains running along the b axis.

10.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 3): o710-1, 2012 Mar 01.
Article in English | MEDLINE | ID: mdl-22412596

ABSTRACT

In the title compound, C(14)H(14)BrNO(4), the dihydro-pyridine ring adopts a screw-boat conformation. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into inversion R(2) (2)(10) dimers.

11.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 3): o544-5, 2011 Feb 02.
Article in English | MEDLINE | ID: mdl-21522312

ABSTRACT

In the title compound, C(16)H(17)NO(5), the six-membered N-containing ring has a half-boat form; the spiro C atom deviates by 0.34 (2) Šfrom the plane (r.m.s. deviation = 0.051 Å) defined by the N and four aromatic C atoms. Intra-molecular N-H⋯O hydrogen bonding generates an S(6) ring motif and the dihedral angle between the mean plane though the S(6) ring and that through the five-atom half-boat plane is 3.39 (2)°. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link mol-ecules into zigzag chains along [001] due to c-glide symmetry, and C-H⋯π inter-actions extend along [010].

12.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 3): o576, 2011 Feb 05.
Article in English | MEDLINE | ID: mdl-21522338

ABSTRACT

In the title compound, C(17)H(21)NO(7), the dihydro-pyridine ring assumes a screw-boat conformation. In the crystal, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules, forming supra-molecular chains running along the b axis.

13.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 3): o672-3, 2011 Feb 19.
Article in English | MEDLINE | ID: mdl-21522421

ABSTRACT

In the crystal of the title compound, C(14)H(15)NO(4), pairs of inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric R(2) (2)(10) dimers. These dimers are further connected via inter-molecular C-H⋯O hydrogen bonds, forming a three-dimensional network. The heterocyclic ring adopts a twisted conformation.

14.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 9): o2332-3, 2010 Aug 18.
Article in English | MEDLINE | ID: mdl-21588678

ABSTRACT

The title compound, C(11)H(13)NO(4), contains a nitrone group, C=N-O-R, the geometry of which shows a Z configuration with near planarity (r.m.s. deviation = 0.0787 Å) around the C=N double bond. An intra-molecular C-H⋯O hydrogen bond generates an S(6) ring motif. In the crystal packing, mol-ecules are linked into R(2) (2)(12) dimers and R(2) (2)(14) rings via C-H⋯O inter-molecular hydrogen bonds.

15.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 9): o2363-4, 2010 Aug 21.
Article in English | MEDLINE | ID: mdl-21588705

ABSTRACT

In the title compound, C(15)H(17)NO(2)S, the dihedral angle between the aromatic rings is 14.47 (8)°. The mol-ecule is bent at the N atom, with a C-SO2-NH-C torsion angle of 79.06 (13)°. In the crystal structure, the sulfonamide groups are hydrogen bonded via N-H⋯O links, forming chains of mol-ecules along the crystallographic b axis. π-π inter-actions [centroid-centroid distance = 3.81 (3) Å] also occur.

16.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 11): o2891-2, 2010 Oct 23.
Article in English | MEDLINE | ID: mdl-21589070

ABSTRACT

The title compound, C(16)H(19)NO(4), the hydrogenated ring adopts a twisted conformation. In the crystal, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric R(2) (2)(10) dimers. These dimers are further connected via inter-molecular N-H⋯O hydrogen bonds, forming infinite double chains along [001].

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