Laura Sbaffi

Variability of the western Mediterranean Sea surface temperature during the last 25,000 years and its connection with the Northern Hemisphere climatic changes

Sea surface temperature (SST) profiles over the last 25 kyr derived from alkenone measurements are studied in four cores from a W-E latitudinal transect encompassing the Gulf of Cadiz (Atlantic Ocean), the Alboran Sea, and the southern Tyrrhenian Sea (western Mediterranean). The results document the sensitivity of the Mediterranean region to the short climatic changes of the North Atlantic Ocean, particularly those involving the latitudinal position of the polar front. The amplitude of the SST oscillations increases toward the Tyrrhenian Sea, indicating an amplification effect of the Atlantic signal by the climatic regime of the Mediterranean region. All studied cores show a shorter cooling phase (700 years) for the Younger Dryas (YD) than that observed in the North Atlantic region (1200 years). This time diachroneity is related to an intra-YD climatic change documented in the European continent. Minor oscillations in the southward displacement of the North Atlantic polar front may also have driven this early warming in the studied area. During the Holocene a regional diachroneity propagating west to east is observed for the SST maxima, 11.5–10.2 kyr B.P. in the Gulf of Cadiz, 10–9 kyr B.P. in the Alboran Sea, and 8.9–8.4 kyr B.P. in the Thyrrenian Sea. A general cooling trend from these SST maxima to present day is observed during this stage, which is marked by short cooling oscillations with a periodicity of 730±40 years and its harmonics.

Apparent long-term cooling of the sea surface in the northeast Atlantic and Mediterranean during the Holocene.

Reconstructions of upper ocean temperature (T) during the Holocene (10–0 ka B.P.) were established using the alkenone method from seven, high accumulation sediment cores raised from the northeast Atlantic and the Mediterranean Sea (361N–751N). All these paleo-T records document an apparent long-term cooling during the last 10 kyr. In records with indication of a constant trend, the apparent cooling ranges from � 0.27 to � 0.151C kyr � 1 . Records with indication of time-variable trend show peak-to-peak amplitudes in apparent temperatures of 1.2–2.91C. A principal component analysis shows that there is one factor which accounts for a very large fraction (67%) of the total variance in the biomarker paleo-T records and which dominates these records over other potential secondary influences. Two possible contributions are (1) a widespread surface cooling, which may be associated with the transition fromthe Hypsithermal interval ( B9–5.7 ka B.P.) to the Neoglaciation (B5.7–0 ka B.P.); and (2) a change in the seasonal timing and/or duration of the growth period of alkenone producers (prymnesiophyte algae). The first contribution is consistent with many climate proxy records from the northeast Atlantic area and with climate model simulations including Milankovitch forcing. The second contribution is consistent with the divergence between biomarker and summer faunal paleo-T fromearly to late Holocene observed in two cores. Further work is necessary, and in particular the apparent discordance between biomarker and faunal T records for the relative stable Holocene period must be understood, to better constrain the climatic and ecological contributions to the apparent cooling observed in the former records. r 2002 Elsevier Science Ltd. All rights reserved.

Millennial- to centennial-scale palaeoclimatic variations during Termination I and the Holocene in the central Mediterranean Sea

Abstract We compared palaeoclimate proxy records of two deep-sea sediment cores from the Tyrrhenian Sea to provide new insights into the climate variability in the Mediterranean basin during Termination I and the Holocene. High-resolution sequences of Globigerina bulloides and Globigerinoides ruber oxygen stable isotope analyses and planktonic foraminifera abundances for cores BS7937 and BS7938 are presented here. The sedimentation rates (on average 18 cm/ky for BS7937 and 25 cm/ky for BS7938) calculated for these cores are among the highest recorded in the Tyrrhenian Sea and the sampling resolution of core BS7938 provides the first centennial-scale study available for the Holocene in this area. At least seven cold episodes, with an average duration of 650 years (from 400 to 1000 years), have been clearly recognised in the record of the last 12 ky in the planktonic foraminiferal and δ 18 O profiles of both cores. The timing and intensity of such coolings is in good agreement with others previously identified in the Mediterranean basin and this testifies to their wide distribution in an area previously thought to be characterised by Holocene climatic stability. This environmental variability has also been further highlighted by the revised biozonation applied to the relative abundances of the main planktonic foraminifera species recognised in the south Tyrrhenian Sea.

Trust and Credibility in Web-Based Health Information: A Review and Agenda for Future Research

Background Internet sources are becoming increasingly important in seeking health information, such that they may have a significant effect on health care decisions and outcomes. Hence, given the wide range of different sources of Web-based health information (WHI) from different organizations and individuals, it is important to understand how information seekers evaluate and select the sources that they use, and more specifically, how they assess their credibility and trustworthiness. Objective The aim of this study was to review empirical studies on trust and credibility in the use of WHI. The article seeks to present a profile of the research conducted on trust and credibility in WHI seeking, to identify the factors that impact judgments of trustworthiness and credibility, and to explore the role of demographic factors affecting trust formation. On this basis, it aimed to identify the gaps in current knowledge and to propose an agenda for future research. Methods A systematic literature review was conducted. Searches were conducted using a variety of combinations of the terms WHI, trust, credibility, and their variants in four multi-disciplinary and four health-oriented databases. Articles selected were published in English from 2000 onwards; this process generated 3827 unique records. After the application of the exclusion criteria, 73 were analyzed fully. Results Interest in this topic has persisted over the last 15 years, with articles being published in medicine, social science, and computer science and originating mostly from the United States and the United Kingdom. Documents in the final dataset fell into 3 categories: (1) those using trust or credibility as a dependent variable, (2) those using trust or credibility as an independent variable, and (3) studies of the demographic factors that influence the role of trust or credibility in WHI seeking. There is a consensus that website design, clear layout, interactive features, and the authority of the owner have a positive effect on trust or credibility, whereas advertising has a negative effect. With regard to content features, authority of the author, ease of use, and content have a positive effect on trust or credibility formation. Demographic factors influencing trust formation are age, gender, and perceived health status. Conclusions There is considerable scope for further research. This includes increased clarity of the interaction between the variables associated with health information seeking, increased consistency on the measurement of trust and credibility, a greater focus on specific WHI sources, and enhanced understanding of the impact of demographic variables on trust and credibility judgments.

Students’ trust judgements in online health information seeking:

As one of the most active groups of Internet users, students and other young people are active users of digital health information. Yet, research into young people’s evaluation of health information is limited, and no previous studies have focused on trust formation. In addition, prior studies on adults’ use of digital information do not reach a consensus regarding the key factors in trust formation. This study seeks to address this gap. A questionnaire-based survey was used to collect data from undergraduate students studying a variety of disciplines in one UK university. The Trust in Online Health Information Scale is proposed, and it includes the following dimensions: authority, style, content, usefulness, brand, ease of use, recommendation, credibility, and verification. In addition, inspection of responses to specific items/questions provides further insights into aspects of the information that were of specific importance in influencing trust judgements.

Gender as an influencer of online health information-seeking and evaluation behavior

This article contributes to the growing body of research that explores the significance of context in health information behavior. Specifically, through the lens of trust judgments, it demonstrates that gender is a determinant of the information evaluation process. A questionnaire‐based survey collected data from adults regarding the factors that influence their judgment of the trustworthiness of online health information. Both men and women identified credibility, recommendation, ease of use, and brand as being of importance in their trust judgments. However, women also take into account style, while men eschew this for familiarity. In addition, men appear to be more concerned with the comprehensiveness and accuracy of the information, the ease with which they can access it, and its familiarity, whereas women demonstrate greater interest in cognition, such as the ease with which they can read and understand the information. These gender differences are consistent with the demographic data, which suggest that: women consult more types of sources than men; men are more likely to be searching with respect to a long‐standing health complaint; and, women are more likely than men to use tablets in their health information seeking. Recommendations for further research to better inform practice are offered.

Modelling trust formation in health information contexts

This study explores trust formation in the context of health information. Trust as an interpersonal notion, when formed in a vulnerable state, is a response or belief about how the trusted will behave towards the trustor. This study focuses on the process of assessing the trustworthiness of information, in a dependency state of information need, through the identification of the many factors influencing this assessment. A set of propositions are developed to suggest the criteria by which trustworthiness is assessed as well as the factors that influence these judgements. The proposed model is tested in a large-scale survey using a trust inventory with factor analysis to explore the constructs of trust formation. Structural equation modelling is used to explore the relationship among the identified criteria and their influencing factors. The resulting framework contributes to the understanding of trust formation in digital information contexts on the criteria of usefulness and credibility and further research into the influencing factors is recommended.

Public libraries and non-users: A comparison between Manchester and Rome

This paper presents the findings of a study conducted with library managers from two major metropolitan areas, Greater Manchester in England and Rome in Italy. The study aims to compare practices, activities and policies adopted in the two cities to attract non-users, with particular attention to the approach that librarians take to resolving the non-user issue. This research also revealed differences in the way public libraries are used in the two areas. In Manchester, libraries are predominantly task orientated, offering access points for community services, whereas in Rome the focus is more on entertainment, leisure, and social events. The non-user profiles differ between cities, with non-users being mostly older teenagers and young adults in Manchester and mostly younger teenagers and pensioners in Rome. Reading groups, a key service for encouraging reading and familiarising with library facilities, are well established in England, with 90% of the libraries in Manchester accommodating one or more groups, compared to only 50% of the libraries in Rome offering usually a single group. In addition, Manchester libraries often have a range of specialised reading groups to suit a large variety of reading tastes. Libraries in both cities are aware of the need for proactive marketing and management of their web presence but should look at other countries’ strategies to expand their range of activities and programmes to attract more public.

Late Quaternary climatic variations on the Latium and Campanian Margin of the Tyrrhenian Sea

A multidisciplinary investigation was carried out on two cores, MC 82-12 (Palinuro intraslope basin) and ML 83-21 (Pontinia intraslope basin), recovered during a cruise carried out in 1983, in the eastern part of the Tyrrhenian Sea, funded by C.N.R. Quantitative analyses of planktonic foraminifers, along with oxygen and carbon stable isotopes analyses, and mineralogical and petrological studies on tephra layers allowed to recognize and date, by means of isotopic stratigraphy, the main climatic events of the Late Quaternary: the Last Glacial Maximum, the Younger Dryas event, as well as Termination IA and IB. The planktonic assemblages recognized in the two cores correlate well between them and with the oxygen isotopic signal, even if there are some discrepancies, related to oceanographic factors other than temperature influencing the foraminifers distribution.RiassuntoUno studio multidisciplinare è stato condotto su due carote sedimentarie, MC 82-12 (bacino di Palinuro) e ML 83-21 (bacino di Pontinia), recuperate durante una crociera del 1983, finanziata dal C.N.R., lungo il margine orientale del Mar Tirreno. Le analisi quantitative sui foraminiferi planctonici, unite alle analisi degli isotopi stabili dell’ossigeno e del carbonio e a studi mineralogici e petrografici di strati sabbiosi di origine vulcanica, hanno permesso di riconoscere e datare, per mezzo della stratigrafia isotopica, gli eventi climatici principali del Tardo Quaternario: l’ultimo massimo glaciale, l’eventoYounger Dryas, così come le due fasi della deglaciazione (Termination IA e IB). Le associazioni planctoniche riconosciute nelle due carote si correlano bene tra di loro e con le curve dell’ossigeno, e le differenze esistenti sono da mettere in relazione, oltre che alla temperatura, ad altri fattori oceanografici, come la salinità, che influenzano la distribuzione dei foraminiferi.

Paleoclimatologia dell’ultima deglaciazione nel Bacino di Cefalù — Mar Tirreno meridionale

During the CNR cruise BS 79 performed in 1979, two gravity cores, BS 79-33 and BS 79-38, were recovered in the Cefalù Basin, in the southern part of the Tyrrhenian Sea. Qualitative and quantitative investigations on benthic and planktonic foraminifera, oxygen and carbon stable isotope measurements have been carried out on the cores. This multidisciplinary investigation has allow us to recognize a continuous, undisturbed stratigraphic sequence of about 20 ka B.P. The intervals of sediment related to the Last Glacial Maximum (LGM), to the Termination IA and Termination IB and to the Younger Dryas (YD) have been recognized. These steps are synchronous with those reported in other parts of the west Mediterranean Sea (e.g.: Strait of Sicily). Four major planktonic assemblages relowed to establish a local biozonation corresponding to the climatic variations obtained fromδ18O dating. Difficulty in the interpretationδ13C of the records is difficult, due to insufficient knowledge of the parameters influencing foraminifera assemblages in the Tyrrhenian Sea.RiassuntoDurante la crociera BS 79 del CNR svoltasi nel 1979 sono state prelevate due carote a gravità, la BS 79-33 e la BS 79-38, nel Bacino di Cefalù, nel Mar Tirreno meridionale. Sulle carote si sono svolte analisi qualitative e quantitative su foraminiferi bentonici e planctonici e analisi isotopiche dell’ossigeno e del carbonio. Tali studi multidisciplinari hanno consentito di riconoscere una sequenza continua ed indisturbata degli ultimi 20 ka circa. Sono stati individuati l’Ultimo Massimo Glaciale (LGM), le Terminazioni IA e IB e loYounger Dryas (YD). Questi eventi sono correlabili con quelli rilevati in altre regioni del Mediterraneo occidentale (es.: Stretto di Sicilia). Sono stati riconosciuti quattro maggiori assemblaggi planctonici che hanno permesso di stabilire una locale biozonazione corrispondente alle variazioni climatiche ottenute con le analisi alδ18O. Le difficoltà nell’interpretazione delδ13C dipendono da una conoscenza non sufficientemente dettagliata dei parametri che influenzano le associazioni di foraminiferi nel Mar Tirreno.