111 research outputs found
Conceivable security risks and authentication techniques for smart devices
With the rapidly escalating use of smart devices and fraudulent transaction of users’ data from their devices, efficient and reliable techniques for authentication of the smart devices have become an obligatory issue. This paper reviews the security risks for mobile devices and studies several authentication techniques available for smart devices. The results from field studies enable a comparative evaluation of user-preferred authentication mechanisms and their opinions about reliability, biometric authentication and visual authentication techniques
How can integrated morphotaxonomy-and metabarcoding-based diatom assemblage analyses best contribute to the ecological assessment of streams?
Environmental conditions, such as nutrient concentrations, salinity, elevation etc., shape diatom assemblages of periphytic biofilms. These assemblages respond rapidly to environmental changes, a fact which makes diatoms valuable bioindicators. Hence, freshwater biomonitoring programmes currently use diatom indices (e.g. EU Water Framework Directive - WFD). To date, microscopy-based assessments require high taxonomic expertise for diatom identification at the species level. High-throughput technologies now provide cost-effective identification approaches that are promising, complementary or alternative tools for bioassessment. The suitability of the metabarcoding method is evaluated for the first time in the Cyprus streams WFD monitoring network, an eastern Mediterranean country with many endemic species and results are compared to the results acquired from the morphotaxonomic analysis. Morphotaxonomic identification was conducted microscopically, using the most updated taxonomic concepts, literature and online resources. At the same time, DNA metabarcoding involved the use of the rbcL 312 bp barcode, high-throughput sequencing and bioinformatic analysis. The ecological status was calculated using the IPS Index. Results show a positive correlation between morpho-taxonomic and molecular IPS scores. Discrepancies between the two methodologies are related to the limitations of both techniques. This study confirmed that Fistulifera saprophila can have a crucial role in key differences observed, as it negatively influences IPS scores and microscopy methods frequently overlook it. Importantly, gaps in the DNA barcoding reference databases lead to a positive overestimation in IPS scores. Overall, we conclude that DNA metabarcoding offsets the morphotaxonomic methodology for the ecological quality assessment of freshwaters
Has climate change over the last ten years caused a banalisation of diatom communities in Cypriot streams?
To unveil possible changes in diatom communities in Cypriot streams over the last ten years or so, we selected samples from the years 2020, 2021, and 2022 for the "recent" dataset (N = 119) and samples from the years 2010 and 2011 for the "historical" dataset (N = 108). Biotic homogenization has become a truly global phenomenon. Here we show that, over the last ten years, in response to increased water temperature, conductivity, and discharge variability due to climate-change, Cypriot stream diatom communities include a higher number of trivial (= widespread, tolerant, and opportunistic), aerial, and thermophilic species, have reduced beta-diversity and increased nestedness. Moreover, IndVal analysis shows that indicator species from the historical dataset were characteristic, often relatively rare species, while the indicators of the recent dataset were a group of typical trivial, eutraphentic, and thermophilic species. As is almost always the case, the diatom communities we studied were subjected to multiple stressors, often affecting them in opposite ways. Besides the increase in trivial species, the reduction in n-diversity, and the rise in nestedness mentioned above, the diatom assemblages we studied also showed an increase in alpha-diversity that could be due to a moderate reduction in nutrients in several sites. Highecological-integrity ecosystems, such as springs, waterfalls, and dripping rock-walls, in particular springs that were shown to be excellent hydrologic refugia in climates heavily affected by climate change, and the stream sites close to them should be carefully protected, as they can be refugia for sensitive and characteristic species that can recolonize the adjacent streams after adverse climatic events
Stimulatory effects of adenosine on prolactin secretion in the pituitary gland of the rat
Stream diatom biodiversity in islands and continents—A global perspective on effects of area, isolation and environment
Aim The species-area relationship (SAR) is one of the most distinctive biogeographic patterns, but global comparisons of the SARs between island and mainland are lacking for microbial taxa. Here, we explore whether the form of the SAR and the drivers of species richness, including area, environmental heterogeneity, climate and physico-chemistry, differ between islands and similarly sized areas on mainland, referred to as continental area equivalents (CAEs). Location Global. Taxon Stream benthic diatoms. Methods We generated CAEs on six continental datasets and examined the SARs of CAEs and islands (ISAR). Then, we compared CAEs and islands in terms of total richness and richness of different ecological guilds. We tested the factors contributing to richness in islands and CAEs with regressions. We used structural equation models to determine the effects of area versus environmental heterogeneity, climate and local conditions on species richness. Results We found a non-significant ISAR, but a significant positive SAR in CAEs. Richness in islands was related to productivity. Richness in CAEs was mainly dependent on area and climate, but not directly on environmental heterogeneity. Species richness within guilds exhibited inconsistent relationships with island isolation and area. Main conclusions Ecological and evolutionary processes shaping diatom island biogeography do not depend on area at the worldwide scale probably due to the presence of distinct species pool across islands. Conversely, area was an important driver of diatom richness in continents, and this effect could be attributed to dispersal. Continents had greater richness than islands, but this was a consequence of differences in environmental conditions such as specific island climatic conditions. We stress the need for more island data on benthic diatoms, particularly from archipelagos, to better understand the biogeography of this most speciose group of algae
Stream diatom community assembly processes in islands and continents: A global perspective
Aim: Understanding the roles of deterministic and stochastic processes in community assembly is essential for gaining insights into the biogeographical patterns of biodiversity. However, the way community assembly processes operate is still not fully understood, especially in oceanic islands. In this study, we examine the importance of assembly processes in shaping diatom communities in islands and continents, while also investigating the influence of climate and local water chemistry variables on species distributions. Location: Global. Taxon: Stream benthic diatoms. Methods: We used diatom datasets from five continents and 19 islands and applied beta diversity analyses with a null model approach and hierarchical joint species distribution modelling. To facilitate comparisons with continents, we used continental area equivalents (CAEs), which represent continental subsets with comparable areas and the same number of study sites as their corresponding islands counterparts. Results: We found that homogeneous selection (i.e., communities being more similar than the random expectation) was the dominant assembly process within islands whereas stochastic processes tended to be more important within continents. In addition, assembly processes were influenced by study scale and island isolation. Climatic variables showed a greater influence on species distribution than local factors. However, in islands, local environmental variables had a greater impact on the distributions of unique taxa as opposed to non-unique taxa. Main Conclusions: We observed that the assembly processes of diatom communities were complex and influenced by a combination of deterministic and stochastic forces, which varied across spatial scales. In islands, there was no universal pattern of assembly processes, given that their influence depends on abiotic conditions such as area, isolation, and environmental heterogeneity. In addition, the sensitivity of species occurring uniquely in islands to local environmental variables suggests that they are perhaps less vulnerable to climatic changes but may be more influenced by changes in local physicochemistry
Six Months of Diazoxide Treatment at Bedtime in Newly Diagnosed Subjects With Type 1 Diabetes Does Not Influence Parameters of β-Cell Function and Autoimmunity but Improves Glycemic Control
Challenges in HIV-prevention microbicide research.
E-Letter response to article Whither or wither microbicides? Science 2008; 321: 532-534.No abstract available
The meaning of pain expressions and pain communication
Both patients and clinicians frequently report problems around communicating and assessing pain. Patients express dissatisfaction with their doctors and doctors often find exchanges with chronic pain patients difficult and frustrating. This chapter thus asks how we could improve pain communication and thereby enhance outcomes for chronic pain patients. We argue that improving matters will require a better appreciation of the complex meaning of pain terms and of the variability and flexibility in how individuals
think about pain.
We start by examining the various accounts of the meaning of pain terms that have been suggested within philosophy and suggest that, while each of the accounts captures something important about our use of pain terms, none is completely satisfactory. We propose that pain terms should be viewed as communicating complex meanings, which may change across different communicative contexts, and this in turn suggests that we should view our ordinary thought about pain as similarly complex. We then sketch what a view taking seriously this variability in meaning and thought might look like, which we call the “polyeidic” view. According to this view, individuals tacitly occupy divergent stances across a range of different dimensions of pain, with one agent, for instance, thinking of pain in a much more “bodycentric” kind of way, while another thinks of pain in a much more "mindcentric” way. The polyeidic view attempts to expand the multidimensionality recognised in, e.g., biopsychosocial models in two directions: first, it holds that the standard triumvirate— dividing sensory/cognitive/affective factors— needs to be enriched in order to capture important distinctions within the social and psychological dimensions. Second, the polyeidic view attempts to explain (at least in part) why modulation of experience by these social and psychological factors is possible in the first place. It does so by arguing that because the folk concept of pain is complex, different weightings of the different parts of the concept can modulate pain experience in a variety of ways. Finally, we argue that adopting a polyeidic approach to the meaning of pain would have a range of measurable clinical outcomes
Value-based integrated (renal) care: setting a development agenda for research and implementation strategies
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