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1.
Polymers (Basel) ; 14(24)2022 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-36559740

RESUMEN

This study analysed the bonding mechanisms and strength between wood and non-wood implants in producing laminated oak-wood beams. The suitability of different types of adhesives, namely for load-bearing and general purpose, was also analysed. Three different types of non-wood implants-carbon fibres, glass fibres, and aluminium were glued with epoxy resin (ER), thermoplastic 1-k polyurethane adhesives (PUR), structural polyurethane adhesives (PUR 2 and PUR 3), and polyvinyl acetate (PVAc) adhesives and bonds were tested for shear strength (SS) according to ISO 6238:2018. Results of the bond quality expressed as the ultimate load to failure and displacement were recorded using the universal mechanical testing machine in combination with the digital image correlation (DIC) method. Before the shear test, all the samples were conditioned in dry and wet climatic conditions. Test results indicated that the application of PUR adhesives for bonding carbon and glass fibres with oak wood could sufficiently replace two-component ER, which is generally recommended for such purposes but is very challenging to utilise in industrial conditions. PVAc adhesives proved efficient only for combination with AL implants and in dry conditions. Aluminium sheets were shown to require surface pre-treatment, such as sanding and degreasing or a different type of adhesive to achieve sufficient adhesion.

2.
Arthropod Struct Dev ; 71: 101203, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36088838

RESUMEN

The presence of morphological integration and modularity of the forcipular apparatus, despite its evolutionary significance, has not been analyzed in centipedes. This morphological structure has a crucial role in feeding and defense, thanks to its poisonous part (forcipules), which is important for catching the prey. The aims of our study were: i) to test the hypothesis of modularity of the forcipular apparatus in centipede Lithobius melanops; and ii) to investigate the influence of allometry on overall morphological integration in the aforementioned species using a geometric morphometric approach. The presence of fluctuating asymmetry was obtained by Procrustes ANOVA. Allometry was significant only for the symmetric component of the forcipular apparatus. The modularity hypothesis was not accepted, because the covariance coefficients for symmetric and asymmetric components were lower than 89.5% and 72.1% (respectively) of other RV coefficients obtained by a random contiguous partition of the forcipular apparatus. Results of the present study indicate that allometry does increase the level of morphological integration in the forcipular apparatus. According to our results, the forcipular coxosternite and forcipules could not be considered as separate modules; namely, they probably share similar developmental pathways and function in different forms of behavior and survival in L. melanops.


Asunto(s)
Evolución Biológica , Quilópodos , Animales
3.
Arch Insect Biochem Physiol ; 109(3): e21866, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35020218

RESUMEN

In the world of complex smells in natural environment, feeding and mating represent two important olfactory-guided behaviors in Drosophila melanogaster (Diptera: Drosophilidae). Diet affects the chemoprofile composition of the individuals, which, indirectly, may significantly affect their mating success. In this study, chemoprofiles of recently mated flies belonging to four D. melanogaster strains, which were fed for many generations on different substrates (standard cornmeal-S strain; banana-B strain; carrot-C strain; tomato-T strain) were identified and quantified. In total, 67 chemical compounds were identified: 48 compounds were extracted from males maintained on banana and carrot, and 47 compounds from males maintained on cornmeal and tomato substrates, while total of 60 compounds were identified in females from all strains. The strains and the sexes significantly differed in qualitative nature of their chemoprofiles after mating. Significant differences in the relative amount of three major male pheromones (cis-vaccenyl acetate-cVA, (Z)-7-pentacosene, and (Z)-7-tricosene) and in female pheromone (Z,Z)-7,11-nonacosadiene among strains were also recorded. Furthermore, multivariate analysis of variance (MANOVA) pointed to significant differences between virgin and mated individuals of all strains and within both sexes. Differences in some of the well known sex pheromones were also identified when comparing their relative amount before and after mating. The presence of typical male pheromones in females, and vice versa may indicate their bidirectional transfer during copulation. Our results confirm significant effect of mating status on cuticular hydrocarbon (CHC) phenotypes in differently fed D. melanogaster flies.


Asunto(s)
Drosophila melanogaster , Atractivos Sexuales , Animales , Drosophila , Femenino , Masculino , Odorantes , Feromonas , Conducta Sexual Animal
4.
Zoology (Jena) ; 149: 125970, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34628210

RESUMEN

Covariation of multiple morphological traits and modularity have been widely studied in the field of evolutionary developmental biology. Subunits of a morphological structure can evolve separately from each other in a modular fashion. The aims of our study therefore were: i) to test the hypothesis of modularity in the dorsal part of the head capsule and the gnathochilarium separately during late postembryogenesis in the julidan millipede Megaphyllum unilineatum (C. L. Koch, 1838) using geometric morphometrics; and ii) to investigate the influence of allometry on overall morphological integration in the dorsal part of the head capsule and the gnathochilarium in the mentioned species. Individuals from different ontogenetic stadia (stadium VI - stadium XI) were included in the analyses. Significant influence of fluctuating asymmetry on the dorsal part of the head capsule shape was detected by Procrustes ANOVA. Regressions were significant for the symmetric component of both analysed morphological traits, while non-significant regression was detected for the asymmetric component of the head capsule's dorsal part. Hypotheses of modularity for the dorsal part of the head capsule and the gnathochilarium are rejected because our results indicate that a small proportion of alternate partitions has higher covariation between subsets of structure than between the hypothesized modules. Contrary to our expectations, results of the present study show that allometry does not increase the level of morphological integration in the dorsal part of the head capsule and the gnathochilarium in M. unilineatum. Based on the obtained results, we conclude that the dorsal part of the head capsule and the gnathochilarium are not composed of independent modules and that in the case of the capsule's dorsal part, developmental processes affect morphological integration in different ways at different levels of shape variation.


Asunto(s)
Artrópodos , Animales , Evolución Biológica , Cabeza , Morfogénesis , Fenotipo
5.
Zookeys ; 930: 75-88, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32390749

RESUMEN

Until now, morphological trait variation has been investigated in several millipede species using geometric morphometrics. The present study is the first attempt to explore sexual shape and size dimorphism (SShD and SSD) of morphological structures in Polydesmida. We here analyse antennal, head, and leg SShD and SSD in Brachydesmus troglobius Daday, 1889. Our results show that SSD exists in all of the analysed structures, while SShD is present only in the legs. In comparison with females, males possess longer and wider legs, as well as longer antennae and a shorter head. Contrary to previous findings in some Julida, in B. troglobiusSSD of the antennae and legs varies more than SShD in these morphological structures.

6.
Arthropod Struct Dev ; 57: 100948, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32416473

RESUMEN

Here we describe in detail the late post-embryonic development of the common European scolopendromorph centipede Cryptops parisi. Canonical variate analyses of two groups of external morphological characters, viz., cephalic capsule characters (head length, length of the anterior and posterior paramedian cephalic sutures) and coxopleuron surface characters (number of pores in the coxal pore-field, number of setae on the posterior coxopleuron edge, their number on the coxal pore-field, and their number posterior to the coxal pore-field) were conducted on a large sample of specimens collected from two localities in Serbia. Ten free-living stages are recognized: three pre-adult stages (adolescens I, II, and III) and seven adult stages (one maturus junior stage, four maturus, and two maturus senior stages). The fourth late post-embryonic stage is the first mature stage in both sexes. Sexual dimorphism in the aforementioned characters was not observed. Morphological variation of coxopleuron characters was more informative for the discrimination of developmental stages in Cryptops than the morphological variation of cephalic capsule characters.


Asunto(s)
Artrópodos/crecimiento & desarrollo , Animales , Artrópodos/anatomía & histología , Femenino , Masculino , Serbia
7.
PLoS One ; 14(1): e0209999, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30605481

RESUMEN

Members of the millipede order Julida rely on dominantly quinonic defensive secretions with several minor, non-quinonic components. The free radical-scavenging activities of ethanol, methanol, hexane, and dichloromethane extracts of defensive secretions emitted by Pachyiulus hungaricus (Karsch, 1881) and Megaphyllum unilineatum (C. L. Koch, 1838) were investigated using the ABTS, DPPH, and total reducing power (TRP) tests. The obtained extracts were also tested for inhibition of acetylcholinesterase and tyrosinase activity. Finally, the antifungal potential of both julid extracts was evaluated against seven Fusarium species. Secretions of both species showed activity against free radicals, acetylcholinesterase, tyrosinase, and all of the selected fungal species. The secretions of P. hungaricus exhibited a more potent antioxidative effect than did those of M. unilineatum, while there were no significant differences of antiacetylcholinesterase activity between the tested extracts. Only the hexane extract of M. unilineatum showed an effect on tyrosinase activity stronger than that of P. hungaricus. Fusarium sporotrichioides, F. graminearum, and F. verticillioides were the fungi most resistant to secretions of both julids. The Fusarium species most susceptible to the secretion of P. hungaricus was F. avenaceum, while the concentrations of M. unilienatum extracts needed to inhibit and completely suppress fungal growth were lowest in the case of their action on F. lateritium. Our data support previous findings that julid defensive secretions possess an antimicrobial potential and reveal their antioxidative and antineurodegenrative properties. Bearing in mind the chemical complexity of the tested defensive secretions, we presume that they can also exhibit other biological activities.


Asunto(s)
Antifúngicos/química , Antioxidantes/química , Artrópodos/química , Inhibidores de la Colinesterasa/química , Fusarium/efectos de los fármacos , Animales , Antifúngicos/farmacología , Antioxidantes/farmacología , Secreciones Corporales/química , Inhibidores de la Colinesterasa/farmacología , Fusariosis/tratamiento farmacológico , Fusariosis/microbiología , Humanos
8.
Zootaxa ; 4455(2): 258-294, 2018 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-30314210

RESUMEN

A review of the genus Typhloiulus Latzel, 1884 (Julida: Julidae) in the Dinaric region is given. Previously published and new faunistic records are provided for each species, together with notes for some of them. Four new species are described: T. clavatus sp. nov., T. gracilis sp. nov., T. opisthonodus sp. nov., and T. parvulus sp. nov., all from caves in Dalmatia and Herzegovina. In addition, we provide the first description of the male of T. insularis Strasser, 1938. Some taxonomic relationships among Typhloiulus species and biogeographical aspects (with distribution maps) of the genus are discussed.


Asunto(s)
Artrópodos , Cuevas , Distribución Animal , Animales , Bosnia y Herzegovina , Masculino
9.
J Chem Ecol ; 43(4): 317-326, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28303527

RESUMEN

Cave animals live under highly constant ecological conditions and in permanent darkness, and many evolutionary adaptations of cave-dwellers have been triggered by their specific environment. A similar "cave effect" leading to pronounced chemical interactions under such conditions may be assumed, but the chemoecology of troglobionts is mostly unknown. We investigated the defensive chemistry of a largely cave-dwelling julid group, the controversial tribe "Typhloiulini", and we included some cave-dwelling and some endogean representatives. While chemical defense in juliform diplopods is known to be highly uniform, and mainly based on methyl- and methoxy-substituted benzoquinones, the defensive secretions of typhloiulines contained ethyl-benzoquinones and related compounds. Interestingly, ethyl-benzoquinones were found in some, but not all cave-dwelling typhloiulines, and some non-cave dwellers also contained these compounds. On the other hand, ethyl-benzoquinones were not detected in troglobiont nor in endogean typhloiuline outgroups. In order to explain the taxonomic pattern of ethyl-benzoquinone occurrence, and to unravel whether a cave-effect triggered ethyl-benzoquinone evolution, we classed the "Typhloiulini" investigated here within a phylogenetic framework of julid taxa, and traced the evolutionary history of ethyl-benzoquinones in typhloiulines in relation to cave-dwelling. The results indicated a cave-independent evolution of ethyl-substituted benzoquinones, indicating the absence of a "cave effect" on the secretions of troglobiont Typhloiulini. Ethyl-benzoquinones probably evolved early in an epi- or endogean ancestor of a clade including several, but not all Typhloiulus (basically comprising a taxonomic entity known as "Typhloiulus sensu stricto") and Serboiulus. Ethyl-benzoquinones are proposed as novel and valuable chemical characters for julid systematics.


Asunto(s)
Artrópodos/química , Benzoquinonas/análisis , Cuevas , Ecosistema , Animales , Artrópodos/clasificación , Artrópodos/genética , Benzoquinonas/química , Benzoquinonas/metabolismo , Evolución Biológica , Cromatografía de Gases y Espectrometría de Masas , Filogenia , Extracción en Fase Sólida
10.
Zootaxa ; 4226(1): zootaxa.4226.1.8, 2017 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-28187635

RESUMEN

As the fourth hydrophilous species of the genus Typhloiulus Latzel, 1884, the new species T. balcanicus Antic sp. nov. is described from two caves in the Stara Planina Mountains of Serbia. A brief discussion of the relationships between the new species and congeners with modified and unmodified mouthparts is presented, as well as short notes on the habitat of the new species and comments on other semiaquatic millipedes with modified mouthparts.


Asunto(s)
Artrópodos , Animales , Cuevas , Ecosistema , Serbia
11.
Chem Biodivers ; 13(2): 224-32, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26880435

RESUMEN

Cuticular hydrocarbons (CHCs) in Drosophila melanogaster represent the basis of chemical communication being involved in many important biological functions. The aim of this study was to characterize chemical composition and variation of cuticular profiles in five D. melanogaster strains. These strains were reared for approximately 300 generations on five diets: standard cornmeal medium and substrates prepared with apple, banana, tomato, and carrot. Differences in quantity and/or quality in CHCs were assumed as a result of activation of different metabolic pathways involved in food digestion and adaptations to the particular diet type. In total, independently of sex and strain, 66 chemical compounds were identified. In females of all strains, 60 compounds were identified, while, in males, 47 compounds were extracted. Certain new chemical compounds for D. melanogaster were found. MANOVA confirmed that CHC amounts significantly depend on sex and substrates, as well as on their interactions. Discriminant analysis revealed that flies belonging to 'apple' and 'carrot' strains exhibited the most noticeable differences in CHC repertoires. A non-hydrocarbon pheromone, cis-vaccenyl acetate (cVA) also contributed to the variation in the pheromone bouquet among the strains. Variability detected in CHCs and cVA may be used in the explanation of differences in mating behaviour previously determined in analyzed fly strains.


Asunto(s)
Drosophila melanogaster/fisiología , Hidrocarburos/análisis , Feromonas/análisis , Acetatos/análisis , Acetatos/metabolismo , Animales , Dieta , Drosophila melanogaster/química , Femenino , Hidrocarburos/metabolismo , Masculino , Ácidos Oléicos/análisis , Ácidos Oléicos/metabolismo , Feromonas/metabolismo
12.
Zootaxa ; 4027(1): 117-29, 2015 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-26624169

RESUMEN

We describe and phylogenetically characterize a new species Niphargus mirocensis from Mt. Miroc, eastern Serbia. This species shows distinct morphology typical for a lake ecomorph of niphargid amphipod, i.e. large and stout body, elongated appendages and raptorial gnathopods and presents the first record of this ecomorph in Carpathian Mountains. Phylogenetic analyses based on Cytochrome Oxidase Subunit 1 gene (COI), Histone (H3) and 28S rRNA (28S) suggests that species is nested within a clade of lake ecomorphs spread in Italy and Central Dinaric Region. The new finding is geographic extension of clade's range, the species of which are generally narrow endemics.


Asunto(s)
Anfípodos/clasificación , Anfípodos/anatomía & histología , Anfípodos/genética , Anfípodos/crecimiento & desarrollo , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Ecosistema , Complejo IV de Transporte de Electrones/genética , Femenino , Tamaño de los Órganos , Filogenia
13.
Zootaxa ; 3904(1): 147-50, 2015 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-25660778

RESUMEN

A new species of Heterolatzelia Verhoeff, 1897, H. karlstrasseri sp. n., is described from the Datlo Cave in east Herzegovina. A brief discussion about the relationship between H. karlstrasseri sp. n. and H. durmitorensis Gulicka, 1968 and a distribution map of the family Heterolatzeliidae are presented. 


Asunto(s)
Artrópodos/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Artrópodos/anatomía & histología , Artrópodos/crecimiento & desarrollo , Peninsula Balcánica , Tamaño Corporal , Ecosistema , Masculino , Tamaño de los Órganos
14.
Schizophr Res ; 150(1): 185-96, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23911252

RESUMEN

BACKGROUND: Debate persists with regard to how best to categorize the syndromal dimension of negative symptoms in schizophrenia. The aim was to first review published Principle Components Analysis (PCA) of the PANSS, and extract items most frequently included in the negative domain, and secondly, to examine the quality of items using Item Response Theory (IRT) to select items that best represent a measurable dimension (or dimensions) of negative symptoms. METHODS: First, 22 factor analyses and PCA met were included. Second, using a large dataset (n=7187) of participants in clinical trials with chronic schizophrenia, we extracted items loading on one or more PCA. Third, items not loading with a value of ≥ 0.5, or loading on more than one component with values of ≥ 0.5 were discarded. Fourth, resulting items were included in a non-parametric IRT and retained based on Option Characteristic Curves (OCCs) and Item Characteristic Curves (ICCs). RESULTS: 15 items loaded on a negative domain in at least one study, with Emotional Withdrawal loading on all studies. Non-parametric IRT retained nine items as an Integrated Negative Factor: Emotional Withdrawal, Blunted Affect, Passive/Apathetic Social Withdrawal, Poor Rapport, Lack of Spontaneity/Conversation Flow, Active Social Avoidance, Disturbance of Volition, Stereotyped Thinking and Difficulty in Abstract Thinking. CONCLUSIONS: This is the first study to use a psychometric IRT process to arrive at a set of negative symptom items. Future steps will include further examination of these nine items in terms of their stability, sensitivity to change, and correlations with functional and cognitive outcomes.


Asunto(s)
Esquizofrenia/fisiopatología , Psicología del Esquizofrénico , Apatía , Bases de Datos Bibliográficas/estadística & datos numéricos , Femenino , Humanos , Masculino , Análisis de Componente Principal , Escalas de Valoración Psiquiátrica , Psicometría , Esquizofrenia/diagnóstico , Estadísticas no Paramétricas
15.
Naturwissenschaften ; 100(9): 861-70, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23907296

RESUMEN

The geophilomorph centipede, Himantarium gabrielis, when disturbed, discharges a viscous and proteinaceous secretion from the sternal glands. This exudate was found by gas chromatography-mass spectrometry, liquid chromatography-high resolution mass spectrometry, liquid chromatography-mass spectrometry-mass spectrometry and NMR analyses to be composed of hydrogen cyanide, benzaldehyde, benzoyl nitrile, benzyl nitrile, mandelonitrile, mandelonitrile benzoate, 3,7,6O-trimethylguanine (himantarine), farnesyl 2,3-dihydrofarnesoate and farnesyl farnesoate. This is the first report on the presence of benzyl nitrile and mandelonitrile benzoate in secreted substances from centipedes. Farnesyl 2,3-dihydrofarnesoate is a new compound, while himantarine and farnesyl farnesoate were not known as natural products. A post-secretion release of hydrogen cyanide by reaction of mandelonitrile and benzoyl nitrile was observed by NMR, and hydrogen cyanide signals were completely assigned. In addition, a protein component of the secretion was analysed by electrophoresis which revealed the presence of a major 55 kDa protein. Analyses of the defensive exudates of other geophilomorph families should produce further chemical surprises.


Asunto(s)
Artrópodos/química , Secreciones Corporales/química , Animales , Cromatografía Liquida , Cromatografía de Gases y Espectrometría de Masas , Espectroscopía de Resonancia Magnética , Nitrilos/química , Proteínas/química , Proteínas/metabolismo
16.
BMC Psychol ; 1(1): 5, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-25566357

RESUMEN

BACKGROUND: The objective of this study was to examine the cross-cultural differences of the PANSS across six geo-cultural regions. The specific aims are (1) to examine measurement properties of the PANSS; and (2) to examine how each of the 30 items function across geo-cultural regions. METHODS: Data was obtained for 1,169 raters from 6 different regions: Eastern Asia (n = 202), India (n = 185), Northern Europe (n = 126), Russia & Ukraine (n = 197), Southern Europe (n = 162), United States (n = 297). A principle components analysis assessed unidimensionality of the subscales. Rasch rating scale analysis examined cross-cultural differences among each item of the PANSS. RESULTS: Lower item values reflects items in which raters often showed less variation in the scores; higher item values reflects items with more variation in the scores. Positive Subscale: Most regions found item P5 (Excitement) to be the most difficult item to score. Items varied in severity from -0.93 [item P6. Suspiciousness/persecution (USA) to 0.69 item P4. Excitement (Eastern Asia)]. Item P3 (Hallucinatory Behavior) was the easiest item to score for all geographical regions. Negative Subscale: The most difficult item to score for all regions is N7 (Stereotyped Thinking) with India showing the most difficulty Δ = 0.69, and Northern Europe and the United States showing the least difficulty Δ = 0.21, each. The second most difficult item for raters to score was N1 (Blunted Affect) for most countries including Southern Europe (Δ = 0.30), Eastern Asia (Δ = 0.28), Russia & Ukraine (Δ = 0.22) and India (Δ = 0.10). General Psychopathology: The most difficult item for raters to score for all regions is G4 (Tension) with difficulty levels ranging from Δ = 1.38 (India) to Δ = 0.72. CONCLUSIONS: There were significant differences in response to a number of items on the PANSS, possibly caused by a lack of equivalence between the original and translated versions, cultural differences among interpretation of items or scoring parameters. Knowing which items are problematic for various cultures can help guide PANSS training and make training specialized for specific geographical regions.

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