Seasonality fluctuations recorded in fossil bivalves during the early Pleistocene: implications for climate change

Understanding the transformations of the climate system may help to predict and reduce the effects of global climate change. The geological record provides a unique archive that documents the long-term fluctuations of environmental variables, such as seasonal change. Here, we investigate how seasonal variation in seawater temperatures varied in the Mediterranean Sea during the early Pleistocene, approaching the Early-Middle Pleistocene Transition (EMPT) and the beginning of precession-driven Quaternary-style glacial–interglacial cycles. We performed whole-shell and sclerochemical stable isotope analyses (δ18O, δ13C) on bivalves, collected from the lower Pleistocene Arda River marine succession (northern Italy), after checking shell preservation. Our results indicate that seawater temperature seasonality was the main variable of climate change in the Mediterranean area during the early Pleistocene, with the Northern Hemisphere Glaciation (NHG) exerting a control on the Mediterranean climate. We show that strong seasonality (14.4–16.0 °C range) and low winter paleotemperatures (0.8–1.6 °C) were likely the triggers leading to the establishment of widespread populations of so called “northern guests” (i.e., cold water taxa) in the Mediterranean Sea around 1.80 Ma. The shells postdating the arrival of the “northern guests” record a return to lower seasonal variations and higher seawater paleotemperatures, with seasonality increasing again approaching the EMPT; the latter, however, is not associated with a corresponding cooling of mean seawater paleotemperatures, showing that the observed seasonality variation represents a clear signal of progressive climate change in the Mediterranean Sea

Laparoscopic colonic resection for splenic flexure cancer: our experience

Background: The treatment of colon cancer located in splenic flexure is not standardized. Laparoscopic approach is still considered a challenging procedure. This study reviews two Institutions experience in laparoscopic treatment of left colonic flexure cancer. Intraoperative, pathologic and postoperative data from patients undergoing laparoscopic splenic flexure resection were analyzed to assess oncological safety as well as early and medium-term outcomes. Methods: From October 2005 to May 2014 laparoscopic splenic flexure resection was performed in 23 patients. Results: Conversion rate was nihil. In 7 cases the anastomosis was performed intracorporeally. Specimen mean length was 21.2 cm, while the distance of distal and proximal resection margin from tumor site was 6.5 and 11.5 respectively. The mean number of harvested lymph nodes was 20.8. Mean operative time was 190 min and mean estimated blood loss was equal to 55 ml. As regard major postoperative complications, one case of postoperative acute pancreatitis and one case of postoperative bleeding from the anastomotic suture line were reported. Conclusions: Although our experience is limited and appropriate indications must be set by future randomized studies, we believe that laparoscopic resection with intracorporeal anastomosis appears feasible and safe for patients affected by splenic flexure cancer

Past excess CO2 worlds: biota responses to extreme warmth and ocean acidification

Anthropogenic burning of fossil fuels have introduced environmental stress that biota are forced to survive. The influence of CO2 concentration on global warming and seawater chemistry is thus subject of much scientific debate. The complex interplay between pCO2, climate change and instability, oceanic acidification and CaCO3 saturation still has to be fully understood, preventing reliable predictions of ecosystem responses. Understanding of the Earth system at time scales longer than human observations has become imperative, because anthropogenic activities are likely to telescope by order of magnitude the rates of climatic change that usually result from geologic processes. The ocean is the oldest and largest ecosystem on Earth; global warming and ocean acidification are major threatens to biologic diversity and functioning of pelagic and neritic habitats. The Phanerozoic record clearly indicates that our planet has experienced similar conditions many times over geological times and sedimentary successions offer the possibility of analyzing episodes when the atmosphere and the ocean experienced CO2 levels comparable or even higher than those projected by CO2 emission scenarios. The general aim of our effort is to investigate the response of pelagic and carbonate platform ecosystems to paleoenvironmental perturbations associated with rapid CO2 addition to the atmosphere-ocean, and in particular to past episodes of global warming and ocean acidification: the Paleozoic-Mesozoic history of planktonic and shallow-water calcifiers indicates that their biodiversity and evolution is intimately linked to the environment. We selected case-histories of past high- CO2 scenarios with geological evidence of climate change, environmental stress, biota adaptation and accelerated evolutionary rates. Specifically, we are investigating: (1) END PERMIAN- EARLY TRIASSIC (253-251 Ma); (2) TOARCIAN OAE (183-182 Ma); (3) EARLY APTIAN OAE1a (120-119 Ma); (4) LATEST CENOMANIAN OAE 2 (94-93 Ma). For all these intervals there is evidence that extreme environmental changes impacted the oceanic biota but consequences on calcifying organisms to be fully understood. Our familiarity with the stratigraphic (pelagic and neritic) records of OAEs provides the background for undertaking a high-resolution analysis of tempo and mode of the oceanic ecosystem response and dynamics under excess CO2- induced ocean acidification, warming and anoxia. OAEs are analyzed in pelagic and neritic ecosystems, while the P/T is studied in shallow-water environments. We aim at contributing to the major issues of recent global changes, by investigating geological examples of extreme warmth and ocean acidification to provide guidance as to the response of biota to an abrupt massive CO2 release

Long-term outcome of laparoscopic ablation therapies for unresectable hepatocellular carcinoma : a single European center experience of 426 patients

Background Radiofrequency ablation (RFA) is widely used as a first-line option in patients with hepatocellular carcinoma (HCC). However, since percutaneous approach of RFA may be, in some cases, unfeasible by the tumor size and its location, laparoscopic ablation therapies (LATs) were used as an alternative. Objective of the present study was to assess the efficacy of laparoscopic ultrasound examination in addition to LATs in the treatment of HCC in patients not eligible for percutaneous RFA or surgical resection. Methods Four hundred and twenty-six patients who underwent LATs were analyzed. Laparoscopic approach was offered to patients fulfilling at least one of the following criteria: (a) patients with a single nodule or up to three nodules smaller than 3 cm not suitable for liver transplantation or not eligible for HR because of severe portal hypertension, impaired liver function, or coexistent comorbidities; (b) patients not suitable for percutaneous RFA because of inconvenient tumor location; and (c) short-term recurrence of HCC (<3 months). Results Technical success was achieved in one session in 396 patients (93 %). One-month mortality and morbidity rates were 0.23 % (1 patient) and 25 % (106 patients), respectively. During a median follow-up of 37.2 months (range 2\u2013193) in the remaining 425 patients, 276 (65 %) developed intra-hepatic recurrence: It appeared as a local tumor progression in 65 cases (15 %). Patients median survival was 39 months (95 % CI 34.8\u201347.2), while overall survivals at 1, 3, and 5 years were 88, 55, and 34 %, respectively. Conclusions In the treatment of HCC, LATs proved to be a safe and effective technique, as they permit to treat with low-morbidity-rate lesions not manageable by percutaneous approach. Moreover, they allow achieving a more accurate staging of the disease in one-fifth of patients, thus better redefining the prognosis of such individuals

What can a shell tell? : the story of the multiproxy bivalve Arctica islandica

Fossil carbonate bivalve shells are archives which can tell us several stories. In this prospect, one of the main character of the Quaternary marine evolution is represented by the multitasking bivalve Arctica islandica; its performances range from the field of biostratigraphy, palaeoclimatology and sclerochronology, but these are only some of its numerous \u2018talents\u2019. Among bivalve molluscs, Arctica islandica is known as the Methuselah because of its remarkable lifespan of up to 500 years. It represents one of the most important boreal guests, which migrated from higher northern latitudes into the Mediterranean Sea in consequence of the climatic cooling leading to the Middle Pleistocene glaciations. For this reason, since the eighties, A. islandica was considered one of the main markers of the Pliocene-Pleistocene boundary (1.8 m.y.), remaining in office until 2010, when, the boundary was lowered at 2.6 m.y. After that it was used to mark the Gelasian-Calabrian boundary. However, A. islandica has its most significant impact in the field of palaeoclimate and palaeoenvironmental reconstructions, recording seawater changes in its shell in the form of variable growth increment widths and variable geochemical properties. It is in fact an excellent proxy for studies of ancient ocean conditions because it sensitively and faithfully records the primary seawater isotope composition with no vital effect in its shell layers. A sclerochemical study performed on A. islandica shells from the Arda River marine succession (Castell\u2019Arquato, Northern Italy) highlights the potential of this species in recording the past seasonal variation occurred during its lifespan. This study allowed to reconstruct in details the climate evolution of the Mediterranean area prior to the Middle Pleistocene continental glaciation, showing that seasonality was the main variable involved in the climate change. The establishment of widespread populations of cold guests in the Mediterranean Sea at about 1.8 m.y. was, in fact, triggered by extreme seasonality; after this episode, the analyzed shells record an increasing trend in seasonality approaching the Middle Pleistocene Transition and the beginning of the continental glaciations in the Northern Hemisphere, which is, however, decoupled from a concomitant cooling of the average seawater temperatures. The examples here presented emphasize the multitasking role of A. islandica during the Quaternary, making it a very powerful tool for numerous and diversified studies

Contributions for a vascular flora of Tuscany. X (606-663)

Contributions for a vascular flora of Tuscany. X (606-663). New localities and/or confirmations concerning 57 specific and subspecific plant taxa of Tuscan vascular flora, belonging to 42 genera and 25 families are presented: Chenopodium, Polycnemum, Salsola (Amaranthaceae), Torilis (Apiaceae), Hieracium, Tragopogon (Asteraceae), Mahonia (Berberidaceae), Lepidium (Brassicaceae), Campanula (Campanulaceae), Herniaria (Caryophyllaceae), Dichondra (Convolvulaceae), Sedum (Crassulaceae), Cyperus, Schoenoplectus (Cyperaceae), Euphorbia (Euphorbiaceae), Ervilia, Medicago, Trifolium, Trigonella, Vicia (Fabaceae), Geranium (Geraniaceae), Juncus (Juncaceae), Tulipa (Liliaceae), Malva (Malvaceae), Broussonetia (Moraceae), Olea (Oleaceae), Oenothera (Onagraceae), Oxalis (Oxalidaceae), Callitriche (Plantaginaceae), Aira, Anthoxanthum, Catapodium, Hordeum, Imperata, Lolium, Poa, Polypogon, Setaria, Triticum (Poaceae), Fagopyrum (Polygonaceae), Aphanes (Rosaceae), Rubia (Rubiaceae). In the end, the conservation status of the units and eventual protection of the cited biotopes are discussed