Dispersal capacities of anadromous Allis shad population inferred from a coupled genetic and otolith approach

2015 ◽  
Vol 72 (7) ◽  
pp. 991-1003 ◽  
Author(s):  
Jean Martin ◽  
Quentin Rougemont ◽  
Hilaire Drouineau ◽  
Sophie Launey ◽  
Philippe Jatteau ◽  
...  
Keyword(s):  
Bayesian Model ◽  
Site Fidelity ◽  
Sampling Location ◽  
Migratory Species ◽  
Long Distance ◽  
Dispersal Capacity ◽  
Allis Shad ◽  
Alosa Alosa ◽  
High Level

Understanding dispersal capacities for migratory species is crucial for their management. By coupling otolith microchemistry and microsatellite genetic analyses, we provided information on snapshot and long-term dispersal capacity of Allis shad (Alosa alosa), an anadromous clupeid in decline throughout its distribution range. The allocation of natal origin was obtained from water chemistry and signatures in otoliths of juveniles and spawners within a Bayesian model. The majority of adults were assigned to a source river with high degrees of confidence; only 4% were undetermined. Otolith natal origins were used to define a population baseline by grouping individuals from the same natal river and not from the same sampling location as usually done. While A. alosa exhibited a high level of natal site fidelity, this species showed weak genetic structure, which supported the evidence of a substantial flow of strayers between river basins in the vicinity or at longer distances. However, long distance straying was probable but not frequent. In a context of global change, straying would be a key mechanism to drive dispersal and allow resilience of Allis shad populations.

Conservation of the Swift Parrot Lathamus discolor ? management lessons for a threatened migratory species

2007 ◽  
Vol 13 (2) ◽  
pp. 111 ◽  
Author(s):  
Debbie Saunders ◽  
Raymond Brereton ◽  
Chris Tzaros ◽  
Mark Holdsworth ◽  
Rob Price
Keyword(s):  
Site Fidelity ◽  
Bird Species ◽  
Migratory Bird ◽  
Small Population ◽  
Assessment Process ◽  
Migratory Species ◽  
Conservation Assessment ◽  
Broad Distribution ◽  
Large Numbers

Conserving habitat for wide-ranging fauna species provides a challenge because impacts on these species tend to be dismissed based on the assumption that there is sufficient habitat in other areas of its range. This incremental loss of habitat is a serious conservation issue for a diversity of bird species. As knowledge of wide-ranging and migratory bird species increases, it often becomes evident that they select specific sites on a regular basis (i.e., the species exhibit site fidelity). Gaining a better understanding of site fidelity and selective habitat use for wide-ranging species is clearly important, but also extremely challenging. In this paper, challenges associated with conservation of the migratory and wide-ranging Swift Parrot Lathamus discolor are discussed as an example of how a recovery programme has aimed to address such conservation and management challenges. Despite the small population size (less than 2 500 birds), broad distribution (1 250 000 km2) and often cryptic nature, the implementation of the national recovery programme has been successful in the identification and protection of important habitats. This has been made possible by involving large numbers of volunteers who collect long-term sighting and habitat data over large areas, together with more detailed ecological research. This information is then used to inform the conservation assessment process and to improve habitat conservation throughout the range of the species.

scholarly journals Psychological studies of stress experienced by seamen during a long-distance sea voyage#

2020 ◽  
Vol 4 (1) ◽  
pp. 049-054
Author(s):  
Plopa Mieczysław
Keyword(s):  
Stress Conditions ◽  
Stress Process ◽  
Long Distance ◽  
Personality Dimension ◽  
Difficult Situation ◽  
Long Time ◽  
Family Variables ◽  
High Level

The issues investigated in the current study pertain to selected psychological aspects of human functioning in long-term stress conditions. Results of the analyses performed in this study have submitted evidence to confirm the hypothesis in which it is stated that staying on the sea for a long time is a difficult situation which contributes - to a greater or smaller extent - to starting the stress process in sailors. The role of interpersonal competencies that has been found most distinct; high level of this variable contributed to reducing both anxiety and the feeling of loneliness. It has been evidenced in the research that the skill of good functioning in varied social groups, which results from high level of development of several traits including: openness, spontaneity, responsibility, and sensitivity, becomes particularly important in long-term difficult situations in which there is little possibility of eliminating the real menace. Another conclusion to be inferred from the research is the one confirming the theoretical suggestion in which the importance of ‘ego strength’ in modifying the course of stress process is emphasised. This personality dimension has turned out to constitute the factor capable of protecting an individual against increase in both anxiety states and the feeling of loneliness during sea isolation. Another issue considered in the current study pertains to defining the role of ‘family variable’ in mediating the course of stress process under conditions of long-term task isolation. The analyses have confirmed the hypothesis in which it was assumed that sailors functioning in family systems characterised by high level of integration and quality, experience lower emotional costs during a voyage. Generally, it may be claimed that - according to the research results of the study - ‘family variables’ may constitute a significant predictor of both the ‘quality’ of a man’s functioning and personal costs he experiences in long-term stress conditions.

scholarly journals Generational shift in the migratory common noctule bat: first-year males lead the way to hibernacula at higher latitudes

2020 ◽  
Vol 16 (9) ◽  
pp. 20200351
Author(s):  
K. A. Kravchenko ◽  
A. S. Vlaschenko ◽  
L. S. Lehnert ◽  
A. Courtiol ◽  
C.C. Voigt
Keyword(s):  
Demographic Data ◽  
Age Groups ◽  
First Year ◽  
Migratory Species ◽  
Long Distance ◽  
Generational Shift ◽  
Migratory Status ◽  
Underlying Mechanisms ◽  
Term Data

Many migratory species have shifted their geographic distribution in response to climate change, yet the underlying mechanisms are poorly understood, particularly for mammals. We hypothesized that generational shifts are underlying the observed colonization of hibernation sites further north in a migratory bat, the common noctule ( Nyctalus noctula) . To evaluate our hypothesis, we collected long-term data on the migratory status and demography of common noctules in a recently colonized hibernation area. Based on isotopic data of 413 individuals, we observed a significant decline in the proportion of long-distance migrants from 2004 to 2015 for both sexes and across all age groups. Demographic data collected between 2007 and 2016 from 3394 individuals demonstrated that subadult males were more abundant during the early colonization stage, followed by a gradual shift to a more balanced age and sex composition. Our results suggest that the colonization of hibernacula at higher latitudes is promoted by generational shifts, involving mostly first-year males. Generational shifts seem to be a likely mechanism for distribution changes in other bats and potentially also in other mammals.

Vivid Imagers Are Better at Detecting Salient Changes

2006 ◽  
Vol 27 (4) ◽  
pp. 218-228 ◽  
Author(s):  
Paul Rodway ◽  
Karen Gillies ◽  
Astrid Schepman
Keyword(s):  
Individual Differences ◽  
Change Detection ◽  
Visual Imagery ◽  
Detection Task ◽  
Level Of Detail ◽  
Detection Accuracy ◽  
Change Detection Task ◽  
Term Change ◽  
High Level

This study examined whether individual differences in the vividness of visual imagery influenced performance on a novel long-term change detection task. Participants were presented with a sequence of pictures, with each picture and its title displayed for 17  s, and then presented with changed or unchanged versions of those pictures and asked to detect whether the picture had been changed. Cuing the retrieval of the picture's image, by presenting the picture's title before the arrival of the changed picture, facilitated change detection accuracy. This suggests that the retrieval of the picture's representation immunizes it against overwriting by the arrival of the changed picture. The high and low vividness participants did not differ in overall levels of change detection accuracy. However, in replication of Gur and Hilgard (1975) , high vividness participants were significantly more accurate at detecting salient changes to pictures compared to low vividness participants. The results suggest that vivid images are not characterised by a high level of detail and that vivid imagery enhances memory for the salient aspects of a scene but not all of the details of a scene. Possible causes of this difference, and how they may lead to an understanding of individual differences in change detection, are considered.

scholarly journals Review on Perioperative and Oncological Outcomes of Robotic Gastrectomy for Cancer

2021 ◽  
Vol 11 (7) ◽  
pp. 638
Author(s):  
Giuseppe Giuliani ◽  
Francesco Guerra ◽  
Lorenzo De Franco ◽  
Lucia Salvischiani ◽  
Roberto Benigni ◽  
...  
Keyword(s):  
English Language ◽  
Length Of Hospital Stay ◽  
Radical Gastrectomy ◽  
Robotic Gastrectomy ◽  
Relevant Evidence ◽  
Relative Paucity ◽  
Duration Of Surgery ◽  
High Level ◽  
Standard Laparoscopic Surgery

Background. Minimally invasive gastrectomy is currently considered a valid option to treat gastric cancer and is gaining increasing acceptance. Recent reports have suggested that the application of robots may confer some advantages over conventional laparoscopy, but the role of robotic surgery in clinical practice is still uncertain. We aimed to critically review the relevant evidence comparing robotic to standard laparoscopic surgery in performing radical gastrectomy. Methods. The Pubmed/Medline electronic databases were searched through February 2021. Paper conference and the English language was the only restriction applied to our search strategy. Results. According to the existing data, robotic gastrectomy seems to provide some benefits in terms of blood loss, rate of conversion, procedure-specific postoperative morbidity, and length of hospital stay. Robotic gastrectomy is also associated with a longer duration of surgery and a higher economic burden as compared to its laparoscopic counterpart. No significant differences have been disclosed in terms of long-term survivals, while the number of lymph nodes retrieved with robotic gastrectomy is generally higher than that of laparoscopy. Conclusions. The current literature suggests that robotic radical gastrectomy appears as competent as the conventional laparoscopic procedure and may provide some clinical advantages. However, due to the relative paucity of high-level evidence, it is not possible to draw definitive conclusions.

scholarly journals Advancement in long-distance bird migration through individual plasticity in departure

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jesse R. Conklin ◽  
Simeon Lisovski ◽  
Phil F. Battley
Keyword(s):  
Bird Migration ◽  
Population Level ◽  
Breeding Site ◽  
Environmental Constraints ◽  
Adaptive Responses ◽  
Long Distance ◽  
Direct Observations ◽  
Breeding Resources ◽  
Plastic Responses

AbstractGlobally, bird migration is occurring earlier in the year, consistent with climate-related changes in breeding resources. Although often attributed to phenotypic plasticity, there is no clear demonstration of long-term population advancement in avian migration through individual plasticity. Using direct observations of bar-tailed godwits (Limosa lapponica) departing New Zealand on a 16,000-km journey to Alaska, we show that migration advanced by six days during 2008–2020, and that within-individual advancement was sufficient to explain this population-level change. However, in individuals tracked for the entire migration (50 total tracks of 36 individuals), earlier departure did not lead to earlier arrival or breeding in Alaska, due to prolonged stopovers in Asia. Moreover, changes in breeding-site phenology varied across Alaska, but were not reflected in within-population differences in advancement of migratory departure. We demonstrate that plastic responses can drive population-level changes in timing of long-distance migration, but also that behavioral and environmental constraints en route may yet limit adaptive responses to global change.

scholarly journals Mapping of affordability levels for photovoltaic-based electricity generation in the solar belt of sub-Saharan Africa, East Asia and South Asia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sándor Szabó ◽  
Irene Pinedo Pascua ◽  
Daniel Puig ◽  
Magda Moner-Girona ◽  
Mario Negre ◽  
...  
Keyword(s):  
East Asia ◽  
South Asia ◽  
Electricity Generation ◽  
Sub Saharan Africa ◽  
Solar Photovoltaic ◽  
Term Operation ◽  
Sub Saharan ◽  
High Level ◽  
Do So

AbstractLack of access to modern forms of energy hampers efforts to reduce poverty. The provision of electricity to off-grid communities is therefore a long-standing developmental goal. Yet, many off-grid electrification projects neglect mid- and long-term operation and maintenance costs. When this is the case, electricity services are unlikely to be affordable to the communities that are the project’s primary target. Here we show that, compared with diesel-powered electricity generation systems, solar photovoltaic systems are more affordable to no less than 36% of the unelectrified populations in East Asia, South Asia, and sub-Saharan Africa. We do so by developing geo-referenced estimates of affordability at a high level of resolution (1 km2). The analysis illustrates the differences in affordability that may be found at the subnational level, which underscores that electrification investments should be informed by subnational data.

scholarly journals Non-Local and Multi-Scale Mechanisms for Image Inpainting

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3281
Author(s):  
Xu He ◽  
Yong Yin
Keyword(s):  
Markov Random Fields ◽  
Receptive Fields ◽  
Image Inpainting ◽  
Long Distance ◽  
Visual Appearance ◽  
Fine Grained ◽  
Multi Scale ◽  
Non Local ◽  
Relationship Of

Recently, deep learning-based techniques have shown great power in image inpainting especially dealing with squared holes. However, they fail to generate plausible results inside the missing regions for irregular and large holes as there is a lack of understanding between missing regions and existing counterparts. To overcome this limitation, we combine two non-local mechanisms including a contextual attention module (CAM) and an implicit diversified Markov random fields (ID-MRF) loss with a multi-scale architecture which uses several dense fusion blocks (DFB) based on the dense combination of dilated convolution to guide the generative network to restore discontinuous and continuous large masked areas. To prevent color discrepancies and grid-like artifacts, we apply the ID-MRF loss to improve the visual appearance by comparing similarities of long-distance feature patches. To further capture the long-term relationship of different regions in large missing regions, we introduce the CAM. Although CAM has the ability to create plausible results via reconstructing refined features, it depends on initial predicted results. Hence, we employ the DFB to obtain larger and more effective receptive fields, which benefits to predict more precise and fine-grained information for CAM. Extensive experiments on two widely-used datasets demonstrate that our proposed framework significantly outperforms the state-of-the-art approaches both in quantity and quality.

scholarly journals Long Term Interactions of Native and Invasive Species in a Marine Protected Area Suggest Complex Cascading Effects Challenging Conservation Outcomes

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 71
Author(s):  
Charalampos Dimitriadis ◽  
Ivoni Fournari-Konstantinidou ◽  
Laurent Sourbès ◽  
Drosos Koutsoubas ◽  
Stelios Katsanevakis
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
High Performance ◽  
Marine Protected Area ◽  
Habitat Degradation ◽  
Population Increase ◽  
Rocky Reef ◽  
Cascading Effects ◽  
High Level

Understanding the interactions among invasive species, native species and marine protected areas (MPAs), and the long-term regime shifts in MPAs is receiving increased attention, since biological invasions can alter the structure and functioning of the protected ecosystems and challenge conservation efforts. Here we found evidence of marked modifications in the rocky reef associated biota in a Mediterranean MPA from 2009 to 2019 through visual census surveys, due to the presence of invasive species altering the structure of the ecosystem and triggering complex cascading effects on the long term. Low levels of the populations of native high-level predators were accompanied by the population increase and high performance of both native and invasive fish herbivores. Subsequently the overgrazing and habitat degradation resulted in cascading effects towards the diminishing of the native and invasive invertebrate grazers and omnivorous benthic species. Our study represents a good showcase of how invasive species can coexist or exclude native biota and at the same time regulate or out-compete other established invaders and native species.

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