Responses of king penguin Aptenodytes patagonicus adults and chicks to two food-related odours

Increasing evidence suggests that penguins are sensitive to dimethyl sulphide (DMS), a scented airborne compound that a variety of marine animals use to find productive areas of the ocean where prey is likely to be found. Here we present data showing that king penguins Aptenodytes patagonicus are also sensitive to DMS. We deployed DMS on a lake near a king penguin colony at Ratmanoff beach in the Kerguelen archipelago. We also presented DMS to ‘sleeping’ adults on the beach. On the lake, penguins responded to the DMS deployments by swimming more, while on the beach, penguins twitched their heads and woke up more for the DMS than for the control presentations. Interestingly, penguins did not respond to cod liver oil deployments on the lake; mirroring at-sea studies of other penguins. Although at-sea studies are needed to confirm that king penguins use DMS as a surface cue that informs them of productivity under the water, this study is an important first step in understanding how these birds locate prey over significant distances

King Penguins Can Detect Two Odours Associated with Conspecifics

Recent studies on olfaction in penguins have focused on their use of odours while foraging. It has been proposed for some seabirds that an olfactory landscape shaped by odours coming from feeding areas exists. Islands and colonies, however, may also contribute to the olfactory landscape and may act as an orienting map. To test sensitivities to a colony scent we studied whether King penguins (Aptenodytes patagonicus) could detect the smell of sand, feathers or feces by holding presentations beneath their beaks while they naturally slept on the beach. Penguins had a significantly greater response to the feathers and feces presentations than to sand. Although only a first step in exploring a broader role of olfaction in this species, our results raise the possibility of olfaction being used by King penguins in three potential ways: (1) locating the colony from the water or the shore, (2) finding the rendezvous zone within the colony where a chick or partner may be found, or (3) recognizing individuals by scent, as in Humboldt penguins (Spheniscus demersus)

The N/Q boundary at 1.64 MA ?

El límite N/Q establecido en Vrica muestra muchos defectos que, en nuestra opinión, le restan utilidad como límite geocronológico. Hay evidencia, en el registro tanto marino como continental, de una primera glaciación en el Hemisferio Norte entre 3,1 y 2,4 MA. En ese tiempo, una agrupación florística de clima frío, el evento «estepa», se encuentra tanto en las series marinas como en las continentales. Desde el punto de vista de la fauna continental, hay un claro recambio de los vertebrados entre el Villafranquiense inferior (Mastodon, Hipparion) y el Villafranquiense superior (Elephas, Equus). La transición tiene lugar en el Villafranquiense medio (2,6-2,4 MA), donde aparecen Elephas y Equus primitivos. La edad del límite de Vrica, de 1,64 MA, fue obtenida asumiendo una velocidad de sedimentación uniforme (310 mm/1000 y) y teniendo en cuenta que este límite está un metro por encima de la transición de polaridad paleomagnética normal-inversa identificada de manera cuestionable como techo de la subzona Olduvai (1 ,67 MA). Esto implicaría una resolución temporal florística-faunística mejor de 30 ka. Finalmente, los resultados palinológicos e isotópicos muestran, en ese momento, pequeñas oscilaciones en lugar de un gran cambio climático. De esta manera los argumentos a favor del límite de 1,64 MA son poco convincentes desde un punto de vista paleontológico, cronológico, paleomagnético y paleoclimático. El límite N/Q, para que las series continentales de Europa noroccidental, es considerada por muchos autores entre 2,5 y 2,3 MA.The N/Q boundary as established in Vrica shows several defects which, in our opinion, detract from its utility as geochronological boundary. There is evidence, in the marine and continental climatic record, of a first glaciation in the Northern Hemisphere between 3.1 and 2.4 MA. At that time, a cold floral assemblage, the «steppe» event, is found in marine and continental series. A less important «steppe» event is reported from the Eburonian and during the Aulla erosional phase (1.8-1.6 MA). From the point of view of continental fauna, there is a clear turnover of vertebrates between the Lower Villafranchian (Mastodon, Hipparion) and the Upper Villafranchian (Elephas, Equus). The transition took place in the Middle Villafranchian (2.6-2.4 MA), with primitive Elephas and Equus. The Vrica boundary age of 1.64 MA was obtained by assuming an uniform sedimentation rate (310 mm/1000 y) and noting that the boundary is 1 metre higher than the normal to reversed polarity transition questionably identified as the top of Olduvai 1.67 MA old. This would imply an unlikely resolution of floral-faunal boundary better than 30 ka. Finally, palynological and isotopic results show small climatic oscillations rather than a strong climate transition. Thus the arguments for a 1.64 MA boundary are unconvincing from paleontological, chronological, paleomagnetic and paleoclimatic viewpoints; furthermore, the N/Q boundary in the continental series of northwestern Europe was considered by many authors to be at 2.5-2.4 MA

Olfactory Sex Recognition Investigated in Antarctic Prions

Chemical signals can yield information about an animal such as its identity, social status or sex. Such signals have rarely been considered in birds, but recent results have shown that chemical signals are actually used by different bird species to find food and to recognize their home and nest. This is particularly true in petrels whose olfactory anatomy is among the most developed in birds. Recently, we have demonstrated that Antarctic prions, Pachyptila desolata, are also able to recognize and follow the odour of their partner in a Y-maze

Regulation of the mTOR signaling pathway: from laboratory bench to bedside and back again

Recent publications have moved us significantly closer to a complete understanding of the mammalian target of rapamycin (mTOR) signaling pathway, which plays a central role in the control of growth and metabolism and is dysregulated in a broad spectrum of human diseases, including cancer, tuberous sclerosis, diabetes, and cardiovascular and neurodegenerative diseases. Rapamycin-related mTOR inhibitors have shown clinical efficacy in several of these diseases, and novel inhibitors currently in development will be valuable tools for further dissections of the mTOR signaling network in human health and disease

Comment on “Marine plastic debris emits a keystone infochemical for olfactory foraging seabirds” by Savocaet al.

In their recent paper, Savoca and collaborators (2016) showed that plastic debris in the ocean may acquire a dimethyl sulfide (DMS) signature from biofouling developing on their surface. According to them, DMS emission may represent an olfactory trap for foraging seabirds, which explains patterns of plastic ingestion among procellariiform seabirds. This hypothesis is appealing, but some of the data that Savoca et al. used to support their claim are questionable, resulting in a misclassification of species, as well as other decisions regarding the variables to include in their models. Furthermore, with their focus on a single lifestyle trait (nesting habit) of dubious relevance for explaining plastic ingestion, Savoca et al. neglect the opportunity to explore other factors that might provide better ecological insight. Finally, we are deeply concerned by the conservation policy recommendation proposed by Savoca et al.—to increase antifouling properties of consumer plastics—which constitutes a substantial environmental risk and delivers the wrong message to decision-makers. The reduction of plastic consumption, waste prevention, and proactive reuse through a circular economy should be at the heart of policy recommendations for future mitigation efforts.info:eu-repo/semantics/publishedVersio

Responses to novelty in wild insular birds: comparing breeding populations in ecologically contrasting habitats

Islands have always provided ideal natural laboratories for assessing ecological parameters influencing behaviour. One hypothesis that lends itself well to testing in island habitats suggests that animals frequenting highly variable environments should be motivated to approach and interact with (i.e. explore) novelty. Intra-species comparisons of populations living in ecologically different island habitats may, thus, help reveal the factors that modulate animals’ responses to novelty. In this study, we presented novel objects to two geographically isolated breeding populations of the black-faced sheathbill (Chionis minor), a sedentary land-based bird that frequents remote sub-Antarctic islands. In the first population (Chionis minor ssp. crozettensis), the “Crozet group” (Baie du Marin, Ile de la Possession, Crozet Islands), breeding pairs inhabit a variable habitat close to penguin (Aptenodytes patagonicus) colonies. In the second population (Chionis minor ssp. minor), the “Kerguelen group” (île Verte, Morbihan gulf, Kerguelen Islands) breeding pairs live in penguin-free territories. In this latter population, the environment is less variable due to the presence of a broad intertidal zone which ensures year-round food availability. At both Kerguelen and Crozet, at least one breeding partner in all pairs approached at least one of the novel objects, and we found no significant differences in the latency of approach between the two populations. However, sheathbills at Crozet touched objects significantly more than birds at Kerguelen, and were also faster to touch them. We discuss how environmental variability, along with other potential influencing factors, may favour exploration of novelty in this wild insular bird

Management of Osteoporosis in Men: A Narrative Review

Male osteoporosis is a still largely underdiagnosed pathological condition. As a consequence, bone fragility in men remains undertreated mainly due to the low screening frequency and to controversies in the bone mineral density (BMD) testing standards. Up to the 40% of overall osteoporotic fractures affect men, in spite of the fact that women have a significant higher prevalence of osteoporosis. In addition, in males, hip fractures are associated with increased morbidity and mortality as compared to women. Importantly, male fractures occur about 10 years later in life than women, and, therefore, due to the advanced age, men may have more comorbidities and, consequently, their mortality is about twice the rate in women. Gender differences, which begin during puberty, lead to wider bones in males as compared with females. In men, follicle-stimulating hormones, testosterone, estrogens, and sex hormone-binding levels, together with genetic factors, interact in determining the peak of bone mass, BMD maintenance, and lifetime decrease. As compared with women, men are more frequently affected by secondary osteoporosis. Therefore, in all osteoporotic men, a complete clinical history should be collected and a careful physical examination should be done, in order to find clues of a possible underlying diseases and, ultimately, to guide laboratory testing. Currently, the pharmacological therapy of male osteoporosis includes aminobisphosphonates, denosumab, and teriparatide. Hypogonadal patients may be treated with testosterone replacement therapy. Given that the fractures related to mortality are higher in men than in women, treating male subjects with osteoporosis is of the utmost importance in clinical practice, as it may impact on mortality even more than in women