The biased evolution of generation time

Many life-history traits, like the age at maturity or adult longevity, are important determinants of the generation time. For instance, semelparous species whose adults reproduce once and die have shorter generation times than iteroparous species that reproduce on several occasions. A shorter generation time ensures a higher growth rate in stable environments where resources are in excess, and is therefore a positively selected feature in this (rarely met) situation. In a stable and limiting environment, all combination of traits (or strategies) that produce the same number of viable offspring on average are strictly neutral even when their generation times differ. We first study the evolution of life-history strategies with different generation times in this context, and show that those with the longest generation time represent the most likely evolutionary outcomes. Indeed, strategies with longer generation times generate fewer mutants per time unit, which makes them less likely to be replaced within a given time period. This `turnover bias' inevitably exists and favors the evolution of strategies with long generation times. Its real impact, however, should depend on the strength and direction of other evolutionary forces; selection for short generation times, for instance, may oppose turnover bias. Likewise, the evolutionary outcome depends on the strength of such selection and population size, comparably to other biases acting on the occurrence of mutations.Comment: Now we also study the evolution of development duration, suggesting that turnover bias is involved in the evolutionary dynamics of any trait linked with the generation tim

INDAGINE ANATOMO ED ISTO-PATOLOGICA SULLO STATO SANITARIO DI SPIGOLE(DICENTRARCHUS LABRAX) PESCATE NEL FIUME ARNO

Non esistendo dati relativi allo stato sanitario di spigole (Dicentrarchus labrax) pescate nel fiume Arno, ed essendo la pesca ed il consumo di tali pesci, una realtà ampliamente praticata localmente, nella Provincia di Pisa, lo scopo di questo lavoro è stato quello di indagare lo stato sanitario di una popolazione di spigola selvatica, pescata nel fiume Arno tramite indagini parassitologiche, citologiche ed istopatologiche. Parallelamente all’indagine sanitaria, ci siamo proposti, tramite indagini istopatologiche, su tessuti branchiali ed epatici, la ricerca di alterazioni suggestive di esposizione cronica ad agenti xenobiotici ed utilizzare i dati raccolti in via preliminare per indagare gli ipotetici rischi sanitari per la tutela della salute del consumatore.Sono state pescate 20 spigole in 3 diverse località del fiume Arno, nei pressi di Pisa. Gli organi sono stati sottoposti ad indagine parassitologica, ed istopatologica per la ricerca dei principali parassiti e di lesioni microscopiche suggestive di malattie infettive o parassitarie. Ulteriormente le branchie ed il fegato sono stati analizzati tramite tecniche istologiche per la ricerca di lesioni suggestive di esposizione cronica ad agenti xenobiotici. GTli unici parasiti isolati sono stati trematodi monogenei identificati come Diplectanum aequans in 4 soggetti. Nessun organo (ad eccetto delle branchie e del fegato) hanno mostrato alterazioni patologiche all'esame istopatologico. Nel testo vengono riportate le alterazioni riportate a livello delle branchie e del fegato. Il presente studio, sebbene basato su tecniche qualitative e con i limiti che queste possono avere, risulta il primo ad indagare localmente una realtà di interesse per il consumatore proprio per il frequente consumo che viene fatto di spigole pescate nel fiume Arno. La tecnica istologica è risultata utile nell’evidenziazione delle lesioni branchiali ed epatiche sebbene aspecifica riguardo alle noxae patogene e quindi di estrema utilità per uno screening iniziale sulla qualità del pescato e per la possibilità di utilizzo dei tessuti branchiali ed epatico quali biomarkers per la qualità sia del pesce sia delle acque. Le presenti indagini dovranno essere confermate tramite tecniche quantitative (analisi tossicologiche, microbiologiche e chimiche sull’acqua) per la ricerca di eventuali xenobiotici presenti in questa specie pescata nel fiume Arno o nell’ ambiente. La spigola infatti , in quanto specie predatrice e quindi biomagnificatore, si presta per monitorare la situazione ambientale nel tempo e parallelamente ad altre specie stanziali nel fiume, che però difficilmente vengono consumate, può fungere da bioindicatore in future ricerche. Senza dubbio lo stato sanitario degli animali inseriti in questo studio è risultato ottimo, come confermato dall’assenza di lesioni macroscopiche e microscopiche. Proprio per questo motivo,considerata l’assenza di lesioni riferibili a malattie infettive e la modesta presenza di parassiti a livello esclusivamente branchiale, negli esemplari prelevati, è probabile che le lesioni degenerative ed infiammatorie rilevate, sebbene di lieve entità, siano con buona probabilità causate da un moderato stress ambientale che merita un approfondimento mirato per la salute del consumatore

GIARDIA AND CRYPTOSPORIDIUM IN RED FOXES (VULPES VULPES): SCREENING FOR COPROANTIGENS IN A POPULATION OF CENTRAL ITALY AND MINI-REVIEW OF THE LITERATURE

Giardia and Cryptosporidium are common protozoan parasites affecting several animal species and humans. The aim of this survey was to investigate, for the first time, their prevalence in red fox (Vulpes vulpes) faecal samples in central Italy. Seventy-one red foxes of different ages and sexes were examined for antigenic detection of Giardia and Cryptosporidium in fecal samples by means of a commercial rapid immunochromatographic test. The sample was randomly selected from foxes culled during a population control program. They were divided into groups based on sex and age ( 641-year-old and >1-year-old). Five (7%) and one (1.4%) out of 71 fecal samples were positive for the Giardia or Cryptosporidium antigens by immunochromatographic assay, respectively, and no coinfections were observed. The present prevalence rates of Giardia and Cryptosporidium antigens in faeces from V. vulpes suggest that this host species is likely to play only a limited role in the spread of the two protozoa in the study area. A concise review of the literature related to Giardia and Cryptosporidium in V. vulpes is presented

Pulmonary Vascular Endothelial Cells

Pulmonary vascular endothelial cells (ECs) line the surface of the lung vasculature and accommodate the various levels of blood flow. Pulmonary endothelium is a critical regulator of vascular homeostasis by inhibiting coagulation of the blood. The ECs bind tissue factor pathway inhibitors (TFPI), modulate hemostasis with opposing effects such as antiplatelet, anticoagulant and fibrinolytic properties. Lung endothelium regulates synthesis and metabolism of vasoactive compounds such as nitric oxide and endothelin-1, both potent regulators of vascular tone. Cytokines, chemokines, interleukins, adhesion molecules, and growth factors can be secreted by pulmonary ECs with positive and adverse effects. Pulmonary endothelium exhibits heterogeneity with diverse expression of molecules and specific differences in signaling induced by various infections such as Gram-positive bacteria. The distinction of macro or microvascular endothelium occurs from the larger vessels to small capillaries in the lung alveoli system. Lectin-binding patterns discriminate between pulmonary artery and pulmonary microvascular capillary endothelium. The lung is one of the body’s organs with the highest expression of vascular endothelial growth factor that stimulates small vessel formation of the microvascular endothelium. Acute respiratory distress syndrome and acute chest syndrome in sickle cell disease are two prototypes of devastating diseases caused by pulmonary EC dysfunction

Sarcoptic mange and other ectoparasitic infections in a red fox (<i>Vulpes vulpes</i>) population from central Italy.

Fifty red foxes (Vulpes vulpes) from the district of Pisa (central Italy) were examined for ectoparasites. Sarcoptic mange was diagnosed on the presence of clearly visible skin lesions with confirmatory demonstration of Sarcoptes scabiei at parasitological and histopathological analysis. Ticks and fleas were collected directly from the carcases during post mortem examination, fixed and identified by morphological examination. For the detection of ear Malassezia and mite infections, cytological and parasitological examinations of ear wax samples were performed. All data were statistically analysed using a χ2 test with the Yates correction. An overall prevalence of 84% for ectoparasitic infections was found in examined subjects. In regard to isolated ectoparasites, 38%, 8%, 82%, 6% and 8% of foxes resulted positive for S. scabiei, Otodectes cynotis, Malassezia spp., fleas (Archaeopsylla erinacei, Pulex irritans, Ctenocephalides canis) and ticks (Ixodes ricinus and Rhipicephalus sanguineus), respectively. Malassezia ear infection was significantly more prevalent in animals older than 1 year (P Sarcoptes-infected animals indicate that sarcoptic mange should be considered the most important ectoparasitic infection of red foxes in the examined area

Aberrant right coronary artery occlusion during the percutaneous pulmonary trunk stenting in a patient with tetralogy of Fallot

Aberrant coronary arteries are frequently observed in patients presenting with Fallot's tetralogy (TOF). Before the complete surgical repair of the TOF, the percutaneously performed pulmonary trunk (PT) angioplasty is often performed in order to temporarily increase the pulmonary circulation, thus increasing the pulmonary vessel size, finally improving surgical outcome. This case reports a 12-year-old boy with a TOF insufficiently improved by surgical correction, in whom a PT angioplasty with stent implantation was complicated by an extrinsic compression of an aberrant right coronary artery (RCA) causing a myocardial ischemia with severe hypotension. The RCA, originating from the left anterior descending coronary artery, passed through the aortic root and the PT and was thus compressed by the PT-stent. Finally the RCA was successfully treated with standard coronary balloon angioplasty and stenting, improving myocardial perfusion and the hemodynamics of the patient, who finally died several days thereafter due to septic shock and massive pulmonary embolis