Intraspecific variability modulates interspecific variability in animal organismal stoichiometry.

Interspecific differences in organismal stoichiometry (OS) have been documented in a wide range of animal taxa and are of significant interest for understanding evolutionary patterns in OS. In contrast, intraspecific variation in animal OS has generally been treated as analytical noise or random variation, even though available data suggest intraspecific variability in OS is widespread. Here, we assess how intraspecific variation in OS affects inferences about interspecific OS differences using two co-occurring Neotropical fishes: Poecilia reticulata and Rivulus hartii. A wide range of OS has been observed within both species and has been attributed to environmental differences among stream systems. We assess the contributions of species identity, stream system, and the interactions between stream and species to variability in N:P, C:P, and C:N. Because predation pressure can impact the foraging ecology and life-history traits of fishes, we compare predictors of OS between communities that include predators, and communities where predators are absent. We find that species identity is the strongest predictor of N:P, while stream or the interaction of stream and species contribute more to the overall variation in C:P and C:N. Interspecific differences in N:P, C:P, and C:N are therefore not consistent among streams. The relative contribution of stream or species to OS qualitatively changes between the two predation communities, but these differences do not have appreciable effects in interspecific patterns. We conclude that although species identity is a significant predictor of OS, intraspecific OS is sometimes sufficient to overwhelm or obfuscate interspecific differences in OS

La satira: uno specchio dell’antipolitica nell’Italia giolittiana

In Italia la stampa satirica ha sempre potuto contare su un nutrito pubblico di lettori. In sede storica, al contrario, non ha goduto della giusta considerazione, pur essendo una fonte fondamentale per fare una storia della mentalità. Più di ogni altro mezzo espressivo, la satira cerca ed esige la complicità del destinatario. L’autore satirico sia che voglia blandire o turbare i propri lettori, non può fare a meno di confrontarsi con la loro mentalità e partire da essa per elaborare le modalità espressive e il contenuto del suo messaggio.Nel corso dell’età giolittiana la difficoltà di costruire un felice rapporto tra governo e governati creò le condizioni per la diffusione di un generalizzato malcontento nei confronti della classe dirigente e della politica tout court. In questo contesto, la satira ha giocato un ruolo significativo nel rappresentare l’opinione pubblica offrendo ai sentimenti antipolitici un ambito entro il quale esprimersi.Prendendo in esame la produzione satirica di un periodico celebre come il «Travaso delle idee» è possibile risalire alla mentalità del ceto piccolo-borghese, al quale il settimanale si rivolgeva, e desumere un paradigma della retorica antipolitica declinata dalla satira.In Italy, the satirical press has always had a wide readership. The historians, on the contrary, rarely have used the satirical press as a source in their studies, although it is a key source to history of mentality. More than any other means of expression, satire requires the complicity of his audience. The satirist, whether he want coax or whether disturb his readers, must confront with their mentality and he must start from it to develop the ways of expression and the content of the message.During the giolittian age the difficulty of building a successful relationship between the government and the citizens created the conditions for the diffusion of a general dissatisfaction with the ruling class and politics in general. In this context, the satire has played a significant role to represent the public opinion and it has offered a framework to the anti-politics feeling to express themselves.Looking to the pages of the «Travaso delle idee», a famous satirical magazine, we can be study and understand the mentality of middle class, and we can derive a paradigm of anti-politic rhetoric declined from satire

The trophic ecology of guppies (poecilia reticulata) from the streams of Trinidad

Several factors may influence intraspecific niche differentiation, such as the different levels of resources or degrees of competition and predation organisms experience. Resource use polymorphism can lead to morphological differentiation and to the evolution of different life history traits. Trinidadian Guppies (Poecilia reticulata) inhabit streams where they experience high or low predation pressure. Guppies living in high (HP) and low predation (LP) sites have evolved different life history traits: HP guppies mature earlier, produce more and smaller offspring, and have higher overall fecundity and reproductive allotment than their LP counterparts.The objective of this dissertation was to investigate the trophic ecology of guppies and its correlation with their life histories patterns. Three methodologies were employed: gut content analysis, gut length measurement, and stable isotope analysis. In the dry season, guppies in HP sites had a higher quality diet, which consisted of a greater proportion of invertebrates. Guppies in HP sites were more selective than guppies in LP sites, avoiding invertebrates of poor quality, as measured by a high carbon:nitrogen ratio. Gut morphology data confirmed these results, as guppies with lower quality diets (from LP sites) had longer guts. Comparisons between dry and wet seasons revealed that the diet of guppies shifted during the wet season, thereby eliminating dietary differences between HP and LP guppies found during the dry season.A survey of HP and LP population pairs from six different rivers conducted in the wet season showed some similarity within stream types in their environmental and biological characteristics but with some differences between rivers. 15N and 13C stable isotope analysis across the surveyed sites showed that LP guppies generally occupied a higher trophic position than HP guppies, but that this relationship was highly influenced by the river of origin. Stable isotopes also indicated that guppies assimilated invertebrates into their tissues more than other dietary items and that the variation in diet composition between sites was high.The results of this dissertation help distinguish the mechanisms by which guppy phenotypes (HP vs. LP) affect their environment, improving the understanding of the feedback between evolutionary and ecological processes in nature.Ph.D., Environmental Science/Ecology -- Drexel University, 201

Scaffold e bioreattori per la costruzione di vasi sanguigni ingegnerizzati

Nell'accezione più generale, l'oggetto di approfondimento di questa tesina è l'approccio dell'ingegneria tessutale allo sviluppo di impianti vascolari. Nello specifico, ci si sofferma su alcuni aspetti della realizzazione di suddetti impianti, che consta di differenti passaggi. In primis si assiste alla preparazione dello scaffold, successivamente avviene la coltura e la semina delle cellule sul supporto ed infine si procede all'impianto nel paziente. Analisi immunoistochimiche permettono poi di valutare il risultato ottenuto. La tesina si aprirà con una rapida presentazione delle tipologie di impianti vascolari, dei richiami al sistema circolatorio e delle relative problematiche. Si tratterà poi dell’approccio dell'ingegneria tessutale ai vasi sanguigni (TEBVs: tissue-engineered blood vessels), passando per gli step citati in precedenza. In seguito si focalizzerà l'attenzione sui due argomenti cardine: i materiali con cui si realizza lo scaffold ed i bioreattori. Per quanto concerne il primo punto, si esamineranno le proprietà e le tecniche di lavorazione dei materiali e si riporteranno per ognuno uno studio ad esso inerente. La discussione verterà poi sui bioreattori, dei quali si analizzeranno la struttura ed il funzionamento, riportando anche in questo caso alcuni esempi delle varie tipologie di bioreattoreope

Pulmonary recurrence from prostate cancer and biochemical remission after metastasis directed therapy. A case report.

We report a case of a 69-years-old man who presented with a solitary 1 cm nodule in the lower lobe of the left lung almost 3 years after radical prostatectomy for pT3aN0M0, Gleason score 4+3 disease, without evidence of osseous or lymphatic spread. Surgical resection of the pulmonary lobe confirmed the metastatic nature of the lesion, with subsequent reduction of serum PSA to undetectable levels. After 2 years from the metastasis resection, serum PSA is still undetectable, without the necessity of additional treatments. Solitary pulmonary metastases from prostate cancer (Pca) are rare in clinical practice, with only 29 previous cases described besides the one that we present

The 100,000 most influential scientists rank : the underrepresentation of Brazilian women in academia

Despite the progress observed in recent years, women are still underrepresented in science worldwide, especially at top positions. Many factors contribute to women progressively leaving academia at different stages of their career, including motherhood, harassment and conscious and unconscious discrimination. Implicit bias plays a major negative role in recognition, promotions and career advancement of female scientists. Recently, a rank of the most influential scientists in the world was created based on several metrics, including the number of published papers and citations. Here, we analyzed the representation of Brazilian scientists in this rank, focusing on gender. Female Brazilian scientists are greatly underrepresented in the rank (11% in the Top 100,000; 18% in the Top 2%). Possible reasons for this observed scenario are related to the metrics used to rank scientists, which reproduce and amplify the well-known implicit bias in peer-review and citations. Male scientists have more self-citation than female scientists and positions in the rank varied when self-citations were included, suggesting that self-citation by male scientists increases their visibility. Discussions on the repercussions of such ranks are pivotal to avoid deepening the gender gap in science

Importance of harvest-driven trait changes for the management of invasive species: letter

International audienceAlthough intraspecific differences between the phenotypes of organisms are an important driver of ecological dynamics (Des Roches et al. 2018), research to help integrate phenotypic variation and its drivers with ecosystem management has been limited. For this reason, the novel conceptual framework proposed by Palkovacs et al. (2018) – which helps to clarify the ecological implications of harvest‐driven trait changes – is timely

Invertebrate metrics based on few abundant taxa outperform functional and taxonomic composition as indicators of agricultural impacts in Atlantic rainforest streams

Metacommunity studies have demonstrated that local macroinvertebrate communities are structured not only by local environmental conditions but also by spatial processes. Effective bioassessment tools should account for spatial processes while doing so with the least amount of cost. In this study, we applied variance partition techniques based on redundancy analysis to assess the performance of three sets of benthic invertebrate metrics in detecting agricultural land-use effects in a SE Brazil rainforest watershed. Macroinvertebrate data were analyzed separately regarding their taxonomic, functional structure and bioindicator metrics developed for the study region. We stipulated that groups of metrics most sensitive to land-use effects should have the highest amount of variance explained by the joint effects of land use and environmental variation, independently of spatial structuring. Statistical analyses were repeated removing rare taxa in order to assess the effects of their inclusion in the responsiveness of each group of metrics. Traditional bioindicator metrics were more responsive to environmental variation associated with agriculture than taxa abundances and functional attributes. Furthermore, a few common taxa drove a high proportion of the variation observed in invertebrate communities, regardless of how invertebrate data were organized. Similar analytic approaches have the potential to be useful in curtailing sorting and identification efforts when developing macroinvertebrate-based biomonitoring protocols, especially in areas where information regarding the taxonomy of benthic communities is still poorly described