Search results for "Animal"
showing 10 items of 22159 documents
Enameloid microstructure in the oldest known chondrichthyan teeth
2009
Botella, H., Donoghue, P.C.J and Martinez-Perez, C. 2009. The enameloid microstructure of the oldest known chondrichthyan teeth. — Acta Zoologica (Stockholm) 90 (Suppl. 1): 103‐108 Previous studies on tooth enameloid microstructure in several chondrichthyan taxa spanning the phylogeny of the group provided support for the homology of chondrichthyan tooth enameloid. This hypothesis requires that a single crystallite enameloid (SCE) monolayer must be present in the teeth of the most primitive chondrichthyan. However, the dental microstructure of the earliest sharks has yet to be investigated. We have studied the tooth enameloid microstructure of the two oldest tooth-bearing shark species curr…
Ultrastructure of posterior sternal glands of Macrotermes annandalei (Silvestri): new members of the sexual glandular set found in termites (Insecta)
2004
0362-2525 (Print) Comparative Study Journal Article; In female alates of Macrotermes annandalei, two types of abdominal glands are involved in the secretion of sex pheromone. Tergal glands are found at the anterior margin of tergites 6-10 and posterior sternal glands (PSGs) are located at the anterior margin of sternites 6-7. The cytological features of both types of glands are quite similar. The fine structural organization of PSGs is studied more precisely and described for the first time. The glandular cuticle is pitted with narrow apertures corresponding to the openings of numerous subcuticular pouches. Several Class 3 glandular units open in each pouch. One canal cell and one secretory…
Pre-sleep arousal and sleep quality during the COVID-19 lockdown in Italy
2021
Abstract Objective The COVID-19 pandemic has strongly affected daily habits and psychological wellbeing, and many studies point to large modifications in several sleep and sleep-related domains. Nevertheless, pre-sleep arousal during the pandemic has been substantially overlooked. Since hyperarousal represents one of the main factors for the development and the perpetuation of chronic insomnia disorder, the assessment of variables associated with high levels of pre-sleep arousal during the pandemic is clinically relevant. The study aimed to assess the prevalence and predictors of perceived sleep quality and pre-sleep arousal in an Italian sample during the COVID-19 lockdown. Methods We used…
Des souris et des vaches capables de percevoir des émotions humaines grâce aux odeurs
2021
Structural Changes in Production of Animals For Slaughter in Poland in 2004–2014 Across the Voivodeships
2017
Celem artykułu jest określenie zmian struktury oraz tempa wzrostu produkcji żywca rzeźnego w województwach Polski w latach 2004–2014 według gatunków, z zastosowaniem klasycznej metody przesunięć udziałów. Ponadto zidentyfikowano i oszacowano udział czynników strukturalnych oraz regionalnych w wielkości efektu globalnego (produkcji żywca rzeźnego w Polsce ogółem) w przekroju województw. Na podstawie wyników badań wykazano, że zróżnicowanie tempa zmian produkcji żywca rzeźnego związane jest przede wszystkim z pozycją konkurencyjną regionu, a w mniejszym stopniu zależne od zmian struktury produkcji
Effect of two distinct implant macro-designs on the osseointegration of bicortically installed implants in two topographic sites. A histomorphometric…
2019
Antecedentes científicos y objetivos de estudio: El uso de implantes dentales como alternativa para la rehabilitación oral ha demostrado su eficacia y mostrando altas tasas de supervivencia. Un aspecto clave de la osteointegración del implante dental está relacionado con la obtención de una estabilidad primaria adecuada, asegurada por el enclavamiento mecánico entre el tejido óseo y la interfaz del implante, la cual depende en parte de la geometría del implante, la rugosidad de la superficie y la técnica quirúrgica para la preparación del lecho implantario. Varios factores están involucrados en la interacción entre la superficie del implante y el hueso nativo circundante durante la osteoint…
Editorial: Neurobehavioural Mechanisms of Resilience and Vulnerability in Addictive Disorders
2021
Actividad antifúngica y antitoxigénica in vitro y en alimentos de bacterias ácido lácticas
2020
El desarrollo de hongos en materias primas, alimentos y piensos puede ser responsable de pérdidas económicas considerables por disminuir la calidad y reducir la vida media de todos ellos. Además, algunos hongos pueden producir compuestos potencialmente tóxicos, lo que supone un problema de seguridad alimentaria para los consumidores. La bioconservación es un concepto que se refiere al empleo de microorganismos o sus productos metabólicos en los alimentos, para inhibir el crecimiento o destruir microorganismos no deseados, con el objetivo de mejorar la seguridad, conservar la calidad y extender la vida útil de los productos alimenticios. La presente Tesis Doctoral tiene por objeto el estudio…
Parasite avoidance behaviours in aquatic environments
2018
Parasites, including macroparasites, protists, fungi, bacteria and viruses, can impose a heavy burden upon host animals. However, hosts are not without defences. One aspect of host defence, behavioural avoidance, has been studied in the terrestrial realm for over 50 years, but was first reported from the aquatic environment approximately 20 years ago. Evidence has mounted on the importance of parasite avoidance behaviours and it is increasingly apparent that there are core similarities in the function and benefit of this defence mechanism between terrestrial and aquatic systems. However, there are also stark differences driven by the unique biotic and abiotic characteristics of terrestrial …
The giant panda is cryptic
2021
The giant panda (Ailuropoda melanoleuca) is an iconic mammal, but the function of its black-and-white coloration is mysterious. Using photographs of giant pandas taken in the wild and state-of-the-art image analysis, we confirm the counterintuitive hypothesis that their coloration provides camouflage in their natural environment. The black fur blends into dark shades and tree trunks, whereas white fur matches foliage and snow when present, and intermediate pelage tones match rocks and ground. At longer viewing distances giant pandas show high edge disruption that breaks up their outline, and up close they rely more on background matching. The results are consistent across acuity-corrected c…