Behaviour-dependent predation risk in swimming zooplankters

Background: The survival of zooplanktonic organisms is determined by their capability of moving in a fluid environment, trading off between the necessities of finding prey and avoiding predators. In previous numerical experiments, we concentrated on the relationship between natatorial modality and encounter success of a virtual copepod swimming in the presence of prey distributed either in patches or uniformly in the environment. Results: In this contribution, we extend this simulation framework to the encounter with chaetognaths, the primary copepod predators, considering different motion rules as a proxy of different swimming strategies and looking at the influence of the concentration of predators and the size of their detection radius in posing a risk on copepod survival. The outcomes of our simulations indicate that more convoluted trajectories are more vulnerable to predator encounter while straighter motions reduce predation risk. Conclusions: Our results are then complemented with those obtained in our previous studies to perform a general cost-benefit analysis of zooplankton motion

Particle exchange and residence times in the North Western Mediterranean

The effects of the hydrodynamic processes on the distribution of passive drifters in the Gulf of Lions (GoL) have been investigated using a Lagrangian approach coupled with a 3D circulation model (Symphonie). We consider passive drifters, for which transport processes are determined solely by the 3D flow fields, which are in turn primarily forced by the North Mediterranean Current (NMC) and by the Rhˆone fresh-water inputs. The model reproduces 600 3D Lagrangian trajectories of particles released along the coastal area of the GoL during the winter period (January-February). The GoL has been divided into four sectors, each corresponding to a zone playing a strategic role in the hydrodynamics of the study area. The macroscopic characteristics of the transport on the shelf zone are analyzed in terms of total concentration and residence times of the cluster released in the basin. Particle distributions are strongly related to the mesoscale and sub-mesoscale hydrodynamic structures on the shelf and to the offshore circulation associated with the NMC. Two crucial areas are identified: a dispersive zone, corresponding to the central part of the continental shelf, and a wide offshore zone, representing an area of both aggregation and transition

An integrated reconstruction of the multiannual wave pattern in the gulf of naples (South-Eastern Tyrrhenian Sea, Western Mediterranean Sea)

Surface gravity waves retrieved by a network of HF (High Frequency) radars and measured in situ by an ADCP (Acoustic Doppler Current Profiler) current meter connected to an elastic beacon were used to carry out a multiple-year characterization of the wave field of the Gulf of Naples (south-eastern Tyrrhenian Sea, western Mediterranean). The aim of the work was to create a climatology of the study area and to demonstrate the potential of an integrated platform for coastal studies. The patterns recorded by the different instruments were in agreement with the wave climatology of the southern Tyrrhenian Sea as well as with previous scores for the same area. The results presented in this work also highlight seasonal and interannual consistency in the wave patterns for each site. In a wider context, this study demonstrates the potential of HF radars as long-term monitoring tools of the wave field in coastal basins, and supports the development of integrated observatories to address large-scale scientific challenges such as coastal ocean dynamics and the impact of global change on the local dynamics

Gulf of Naples Advanced Model (GNAM): A Multiannual Comparison with Coastal HF Radar Data and Hydrological Measurements in a Coastal Tyrrhenian Basin

High-resolution modelling systems have increasingly become an essential requirement to investigate ocean dynamics over a wide range of spatial and temporal scales, and to integrate the punctual ocean observations. When applied in coastal areas, they also have the potential to provide a detailed representation of transport and exchange processes at the sub-basin scale. This paper presents a validation exercise between the surface fields generated by the regional ocean modeling system (ROMS), developed for the Tyrrhenian Sea and downscaled for the Gulf of Naples (GNAM Gulf of Naples advanced model), and a 4 year-long (2009–2012) record of high-frequency radar (HFR) data. The comparison between hourly and seasonal model results and HFR surface fields is focused on the Gulf of Naples (GoN), where an observational network of three HFR sites has been operational since 2004, and on a specific subdomain characterized by the presence of the Sarno river, a long-term ecological research station (LTER-MC) and one important canyon area. An evaluation on a transect delimiting inshore–offshore zones in the GoN is also presented. The GNAM model was also compared with in situ hydrological parameters of temperatures and salinities retrieved at the LTER-MC fixed monitoring station. According to the skill metrics, basic circulation features are accurately reproduced by the circulation model, despite some model drawbacks in terms of increment of energy content in the surface current field occurring during specific seasonal events. The results allow us to identify potential model errors and to suggest useful improvements, the outcome also confirms the unique capability of HF radar systems to provide fine-scale measurements for the validation of numerical models and to counterbalance the lack of high-resolution measurements in coastal areas. © 2022 by the authors

Postcolonial Matters: Tra gesti politici e scritture poetiche

[Italiano]: Questo volume raccoglie i contributi della giornata di studio “Postcolonial Matters. Tra gesti politici e scritture poetiche”, ospitata dal Dipartimento di Scienze Umane e Sociali dell’Università degli studi di Napoli “L’Orientale” il 14 giugno 2012. Quali sono, oggi, le questioni postcoloniali? E perché il postcoloniale ci importa, ci ri-guarda? Gli autori e le autrici delle scritture qui presentate si confrontano con queste domande a partire da una serie di pratiche materiali (teoria, editoria, a ivismo, ricerca, arte) da essi stessi agite ed esperite. Con contributi di: Francesco Camagni, Alessandra Cianelli, Anna Curcio, Lidia Curti, Beatrice Ferrara, Bülent Küçük & Ceren Özselçuk, Annalisa Piccirillo & Viola Sarnelli, Gabriele Proglio, Nirmal Puwar, Ashwani Sharma & Sanjay Sharma ./[English]: The essays in this volume stem from the workshop “Postcolonial Matters. Between political gestures and poetical writings”, hosted at the Department of Social and Human Sciences of the Università degli studi di Napoli “L’Orientale” on the 14th June 2012. Why does the postcolonial “matter” to the contemporary? What is our concern with the postcolonial today? All contributions reflect on these questions from a very situated standpoint, expanding on a concrete, localised practice (critical theory, editorial practice, political activism, art making, research) with a global relevance. With essays by: Francesco Camagni, Alessandra Cianelli, Anna Curcio, Lidia Curti, Beatrice Ferrara, Bülent Küçük & Ceren Özselçuk, Annalisa Piccirillo & Viola Sarnelli, Gabriele Proglio, Nirmal Puwar, Ashwani Sharma & Sanjay Sharma

Sea Storm Analysis: Evaluation of Multiannual Wave Parameters Retrieved from HF Radar and Wave Model

Intense atmospheric disturbances, which impact directly on the sea surface causing a significant increase in wave height and sometimes strong storm surges, have become increasingly frequent in recent years in the Mediterranean Sea, producing extreme concern in highly populated coastal areas, such as the Gulf of Naples (Western Mediterranean Sea, Central Tyrrhenian Sea). In this work, fifty-six months of wave parameters retrieved by an HF radar network are integrated with numerical outputs to analyze the seasonality of extreme events in the study area and to investigate the performance of HF radars while increasing their distances from the coast. The model employed is the MWM (Mediterranean Wind-Wave Model), providing a wind-wave dataset based on numerical models (the hindcast approach) and implemented in the study area with a 0.03° spatial resolution. The integration and comparison with the MWM dataset, carried out using wave parameters and spectral information, allowed us to analyze the availability and accuracy of HF sampling during the investigated period. The statistical comparisons highlight agreement between the model and the HF radars during episodes of sea storms. The results confirm the potential of HF radar systems as long-term monitoring observation platforms, and allow us to give further indications on the seasonality of sea storms under different meteorological conditions and on their energy content in semi-enclosed coastal areas, such as the Gulf of Naples

Wind direction data from a coastal HF radar system in the gulf of naples (central mediterranean sea)

Results on the accuracy of SeaSonde High Frequency (HF) radar wind direction measurements in the Gulf of Naples (Southern Tyrrhenian Sea, Central Mediterranean Sea) are here presented. The investigation was carried out for a winter period (2 February-6 March) and for one summer month (August) of the reference year 2009. HF radar measurements were compared with in situ recordings from a weather station and with model data, with the aim of resolving both small scale and large scale dynamics. The analysis of the overall performance of the HF radar system in the Gulf of Naples shows that the data are reliable when the wind speed exceeds a 5 m/s threshold. Despite such a limitation, this study confirms the potentialities of these systems as monitoring platforms in coastal areas and suggests further efforts towards their improvement

Nonadditive effects of the environment on the survival of a large marine fish population

Climate can affect population dynamics in indirect ways via nonadditive forcing by external variables on internal demographic rates. Current analytical techniques, employed in population ecology, fail to explicitly include nonadditive interactions between internal and external variables, and therefore cannot efficiently address indirect climate effects. Here, we present the results of an analysis, employing specifically developed statistical methodology, on density‐dependent survival of walleye pollock (Theragra chalcogramma) prerecruitment stages in relation to background environmental variables in the Gulf of Alaska. We found that spring winds and water temperature mediate the intensity of density‐dependent survival from the eggs to the age‐0 stage. Fall water temperature and juvenile pollock predator abundance mediate density dependence from the age‐0 to the age‐1 stage. The inclusion of such nonadditive and nonlinear effects in a population dynamics model improved our ability to simulate pollock recruitment. Our results point to the importance of understanding nonadditive and nonlinear interactions between external (climate) and internal factors in the presence of underlying environmental variation. These topics are discussed in the context of current research priorities in population ecology and conservation biology.Keywords: Theragra chalcogramma, Gulf of Alaska, density dependence, nonadditivity, environmental change, phase dependence, walleye polloc

Feasibility and acceptability of SEPA+PrEP: An HIV prevention intervention to increase PrEP knowledge, initiation, and persistence among cisgender heterosexual Hispanic women

The HIV epidemic disproportionately affects Hispanics in the U.S., with Hispanic women (HW) accounting for 18% of new HIV diagnoses in 2019 despite comprising only 16% of the female population. The imbalance of power related to cultural values and HW’s lack of knowledge and low perception of risk for HIV interferes with prevention efforts (e.g., condom use, HIV testing, and Pre-Exposure Prophylaxis [PrEP]). It is estimated that in 2019, only 10% of women in the U.S. who could benefit from PrEP were given prescriptions for it. This number is estimated to be significantly lower among HW. PrEP is highly effective for preventing HIV, reducing the risk of acquiring HIV from sexual activity by about 99%. To respond to this need, we developed SEPA+PrEP, a biobehavioral HIV prevention intervention that adapted and integrated SEPA (Salud/Health, Educación/Education, Prevención/ Prevention, Autocuidado/Self-Care), an empirically validated behavioral HIV prevention intervention, with the evidence-based biomedical strategy of PrEP. This study aimed to investigate the feasibility and acceptability of SEPA+PrEP among cisgender heterosexual Hispanic women (HW). We used a mixed methods approach to gather data from 44 HW living in the City of Homestead and its surrounding communities in Miami-Dade County, Florida. None of the participants knew about PrEP prior to participating in the study, and the majority (70.5%, n = 23) had not used condoms when engaging in vaginal sex during the previous three months. Overall, study results suggest that SEPA+PrEP is an acceptable and feasible intervention to prevent HIV among HW, with a focus on PrEP knowledge, initiation, and maintenance