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The importance of habitat-forming species, particularly cold-water corals like Dendrophyllia ramea, cannot be overstated as they provide crucial physical structures that offer shelter, food, and breeding habitat for a range of other species. We studied the spatial distribution and abundance of D. ramea, its associated species and the impact of human activities in a population of the Herradura, Granada in the western Mediterranean. Video transects were conducted at different depths, and epibiont samples were collected to describe the coral assemblage and the diversity of associated organisms. Dendrophyllia ramea presented high abundances at an unusually shallow depth in the Mediterranean, ranging from 30 to 48 m, despite typically being found between 50 and 500 m, with recordings indicating occurrences as deep as 1000 m, and hosting a high number of epibionts and macro-benthic organisms associated with coral reefs. Bryozoans showed a close relationship with D. ramea as they are important components of both the reef and the epibiont community. This study identified 63 new species and 15 new genera associated with cold-water corals. This study showed the importance of D. ramea as a nursery site, even for other habitat-forming species. The major threat to this community is human activity (fishing, littering and free anchoring), with the most abundant types of waste being rubber, glass/ceramics, and plastic polymers, and many fishing lines and nets damaging the corals. Overall, this study emphasises the urgent need to protect cold-water corals and their associated species and reduce the impact of human activities on marine ecosystems.
The femtosecond laser filament-induced air laser plays a significant role for the remote sensing of air pollutants. The spatial distributions of air laser intensity were investigated experimentally in previous studies. However, the mechanism of the air laser propagation properties inside the filament plasma has not been quite clear yet. Moreover, few studies have been dedicated to the reproduction of the air laser profile from nitrogen molecules propagating in the filament plasma based on the numerical simulation method. In this study, the lasing action of the air laser from the transition of the first negative (0,0) band of nitrogen ions at 391 nm was simulated during the femtosecond laser filamentation. The beam profile of the air laser changes from a Gaussian or super-Gaussian shape to an outer ring structure by increasing the filament length or nitrogen ion density, which is in accord with the previous experimental result. A multiple-diffraction effect has been proposed to clarify the mechanism of the outer rings beam pattern formation, which is induced by the dynamical interaction between the lasing effect and diffraction effect of the air laser propagating inside the filament plasma. In addition, the amplified air laser power as a function of both the filament length and nitrogen ion density was investigated. Our study would pave the way to improve the energy conversion efficiency and directivity of remote air lasers, which would be significant for remote sensing applications.
Intertidal macrobenthos at the small Chernaya Bight (the White Sea) was surveyed six times during 1993–2018 in order to study spatiotemporal variability. Distributions of sediments and macrophytes were highly variable in both space and time, as were most macrofaunal community attributes. Biomass slightly increased with time, while no long-term trends were found in total abundance, diversity, or functional structure. All community attributes were patchily distributed across the beach, and their patterns were not spatially autocorrelated and poorly associated with sediment properties, but changed considerably from year to year. Temporal changes in the community composition were considerable but less substantial compared with the spatial variations. The overall dynamics of species structure did not show any regular trend-like pattern but formed quasicyclic trajectories in ordination space, with nondirectional, spatially noncorrelated fluctuations around some relatively stable state. Comparison with two other neighbouring intertidal sites, studied annually in 1987–2017, showed that macrofauna at every site had similar average biomasses and common dominant species; however, the communities maintained their specificity in structure and exhibited distinct types of dynamics. In particular, the communities demonstrated different long-term trends in total biomass and diversity and followed their own paths in dynamics, appearing as differently oriented interannual trajectories. Nine most abundant species revealed no significant among-site correlations in abundance, and only two bivalve species showed good intersite agreement in dynamics of biomass. We suggest that local benthic communities are largely influenced by site-specific environmental conditions, resulting in independent and even opposite patterns of dynamics in neighbouring localities.
Avian schistosomes are snail-borne trematode parasites (Trichobilharzia spp.) that can cause a nasty skin rash in humans when their cercariae mistake us for their normal bird hosts. We sought to investigate drivers of the spatial distribution of Trichobilharzia cercaria abundance throughout Northern Michigan lakes. For 38 sites on 16 lakes, we assessed several dozen potential environmental predictors that we hypothesized might have direct or indirect effects on overall cercaria abundance, based on known relationships between abiotic and biotic factors in wetland ecosystems. We included variables quantifying local densities of intermediate hosts, temperature, periphyton growth rates, human land use and hydrology. We also measured daily abundance of schistosome cercariae in the water over a 5-week period, supported by community scientists who collected and preserved filtered water samples for qPCR. The strongest predictor of cercaria abundance was Lymnaea host snail density. Lymnaea density was higher in deeper lakes and at sites with more deciduous tree cover, consistent with their association with cool temperature habitats. Contrary to past studies of human schistosomes, we also found a significant negative relationship between cercaria abundance and submerged aquatic vegetation, possibly due to vegetation blocking cercaria movement from offshore snail beds. If future work shows that these effects are indeed causal, then these results suggest possible new approaches to managing swimmer's itch risk in northern MI lakes, such as modifying tree cover and shallow-water vegetation at local sites.
Combining the biogeography and phylogenetic patterns of parasite-host associations allows a better understanding of the history of parasite–host interactions, which can be achieved via biogeographic regionalization incorporating phylogenetic information. Recently, the concepts of evoregions (regions where a majority of species evolved from one or several ancestors inhabiting these regions) and evolutionary transition zones (regions of high phylogenetic turnover) have been proposed, coupled with a classification approach for these concepts. We applied this approach to 206 flea species and 265 host species of the Palearctic and aimed to identify evoregions and evolutionary transition zones for both fleas and hosts and to understand whether these evoregions and transition zones match each other. We identified 5 evoregions with 3 transition zones for either fleas or hosts, but neither the positions and boundaries of the flea and host evoregions nor the transition zones coincided. Indications of multiple geographic centres of diversification of the same flea lineages suggested that (a) the common evolutionary history of fleas and hosts was characterized by multiple events other than codiversification and that (b) dispersal played an important role in flea and host assemblies. Barriers to dispersal could be represented by landscape features (deserts and mountain ranges) and/or climate differences.
The southern giant petrel (Macronectes giganteus) is a widely distributed top predator of the Southern Ocean. To define the fine-scale foraging areas and habitat use of Antarctic breeding populations, 47 southern giant petrels from Nelson Island were GPS-tracked during the summers of 2019–2020 and 2021–2022. Step-selection analysis was applied to test the effects of environmental variables on habitat selection. Visual overlap with seal haul-out sites and fishing areas was also analysed. Birds primarily used waters to the south of the colony in the Weddell and Bellingshausen seas. Females showed a broader distribution, reaching up to -70°S to the west of Nelson Island, while males were mainly concentrated in waters off the northern Antarctic Peninsula. Habitat selection of both sexes was associated with water depth and proximity to penguin colonies. Both overlapped their foraging areas with fishing sites and females in particular overlapped with toothfish fishery blocks in Antarctica and with fishing areas in the Patagonian Shelf. Due to their habitat associations and overlap with fisheries, when harnessed with tracking devices and animal-borne cameras, giant petrels can act as platforms for monitoring the condition and occurrence of penguin colonies, haul-out sites and unregulated fisheries on various temporal and spatial scales in Antarctica.
The maned wolf Chrysocyon brachyurus, the fourth largest canid, is categorized as Near Threatened on the IUCN Red List. The objectives of this study were to update information on the occurrence of this species in Argentina, compare the current distribution to that previously described for 1988–2008, and indicate the areas in which the species is exposed to particular hazards. We created a database that included 1,051 new records of C. brachyurus for 2009-2021, in addition to records for 1988–2008 that had not been reported previously. We calculated the area of occupancy of the species in Argentina to be 500,000 km2. Most of the new records of C. brachyurus are in the Chaco Seco, Espinal and Pampas ecoregions. Our findings indicate a current area of occupancy 61% higher than that calculated from records for 1988–2008. However the location and frequency of reported threats and the intense environmental transformation that characterizes the areas for which we obtained new records suggest counterintuitive implications for the conservation of the species because of increased human–wildlife interactions. Our study reveals the need for systematic research to improve the understanding of the ecological processes that affect the maned wolf in Argentina, and will aid in the development of conservation strategies for the species.
Northeast Arctic cod, saithe and haddock are among the most important fisheries resources in Europe, largely shipped to various continental markets. The present study aimed to map the presence and distribution of larvae of parasitic nematodes in the Anisakidae family which are of socioeconomic and public health concern. Fishes were sourced from commercial catches during winter or spring in the southern Barents Sea. Samples of fish were inspected for nematodes using the UV-press method while anisakid species identification relied on sequencing of the mtDNA cox2 gene. Anisakis simplex (s.s.) was the most prevalent and abundant anisakid recorded, occurring at high infection levels in the viscera and flesh of cod and saithe, while being less abundant in haddock. Contracaecum osculatum (s.l.) larvae, not found in the fish flesh, showed moderate-to-high prevalence in saithe, haddock and cod, respectively. Most Pseudoterranova spp. larvae occurred at low-to-moderate prevalence, and low abundance, in the viscera (Pseudoterranova bulbosa) and flesh (Pseudoterranova decipiens (s.s.) and Pseudoterranova krabbei) of cod, only 2 P. decipiens (s.s.) appeared in the flesh of saithe. Body length was the single most important host-related factor to predict overall abundance of anisakid larvae in the fish species. The spatial distribution of Anisakis larvae in the fish flesh showed much higher abundances in the belly flaps than in the dorsal fillet parts. Trimming of the flesh by removing the belly flaps would reduce larval presence in the fillets of these gadid fish species by 86–91%.
An integrated study of the zooarchaeological, iconographic, and artefactual data from the Etruscan site of Poggio Civitate (Murlo, Italy), inhabited from the eighth to the sixth century bc, reveals intra-site differences in the distribution and disposal of animal body parts and species represented, including wild animals. Smaller mammals and birds that would be trapped are encountered more frequently in the site's workshop area and larger prey (deer, wolf, bear, and aurochs) that would be hunted are found more often in the area of the elite residence. We suggest that some of these remains are evidence that hunting was for the purpose of trophy display by the elites of Poggio Civitate and we discuss the social implications of such an activity in this community.
Bemisia tabaci is a complex of species, which is considered the most common and important pest of a wide range of crops belonging to many different botanical families. In Argentina, this species is recognized as a vector of geminiviruses, and Middle East-Asia Minor 1, Mediterranean, New World and New World 2 have been found to coexist in the same area. Landscape elements, like habitat patch area and isolation, define the habitat configuration and have a direct effect on insect populations between and within host patches. In this paper, we analyse the effect of potato patch configuration on the distribution and abundance of B. tabaci. Potato patches were identified using Landsat TM5 and TM7 images, and a supervised classification was performed to quantify the spatial distribution of the patches in the whole study area. Potato patch metrics were estimated using Fragstats 4.4. Generalized linear mixed models were employed to analyse the relationship between whiteflies and landscape configuration, through a multimodel inference approach, finding that B. tabaci abundance and landscape metrics were very variable. After a multimodel selection process, we found that perimeter-to-area ratio and Euclidean distance between patches were the variables that best explained whitefly abundance in potato patches. Implications of these findings are discussed.
Roman military bases were once regarded as strictly male domains with the only women living there being the senior officers’ wives. This view was challenged by studies that used material culture to identify women in Roman forts and interpret the roles they played. The best of this work considers both the multiple identities expressed through objects and the complexities of depositional and recovery processes. The article presented here fits into this recent development, as it investigates the presence of women in the Augustan military base and the Flavio-Trajanic fortress on the Hunerberg in Nijmegen, the Netherlands, by examining the spatial distribution of brooches (fibulae) associated with women. The distribution of female brooches is compared to that of military (male) brooches in order to highlight and interpret any significant patterns. While numbers are small, the quality of the contextual information allows for the examination of depositional and recovery practices. The paper also raises wider questions about the possibility of ‘gendering’ brooches.
Both decreases in compositional similarity with increasing geographic distances between sites (i.e. distance–decay relationship) and vertical stratification of species composition are key issues in ecology. However, the intersection between these two trends has scarcely been investigated. Here we use identical sampling methods in the canopy and at ground level in a tropical rainforest remnant on the coast of the Gulf of Mexico to evaluate, for the first time, a distance–decay relationship within vertical strata in insect assemblages. We found that the ant assemblage was vertically stratified; ant species richness was higher at ground level than in the canopy, and the species composition differed between the two vertical strata. Moreover, we observed that β-diversity increased with geographic distance at ground level, but not in the canopy strata. However, contrary to our prediction, there was less species turnover (lower β-diversity) between vertical strata than between trees. These findings may reflect differences in the dispersal capacity and nest habit of ants from each vertical stratum, and also habitat heterogeneity on the horizontal scale, e.g. the species of sampled trees. Our results illustrate the importance of sampling more than one vertical stratum to understand the spatial distribution patterns of biological diversity in tropical rainforests.
The analysis of the geographical distribution of hospital cases is obviously important for the purpose of planning hospital services, but it is of even greater significance in the planning of psychiatric services. This concern motivated our seven-year-long study, which examined hospitalization risks among various categories of psychiatric disorders in the major German city of Hamburg. Our database encompassed 77% (n = 64,000) of all psychiatric admissions in a total of 41 hospitals, most of which are general hospitals. In order to carry out the geographical analysis we employed a new statistical method based on a mixture distribution model. According to our findings, the strongest indications of an increased frequency were among male cases of schizophrenia, drug abuse and organic psychoses, and female cases of neurotic disorders, personality disorders, drug abuse and schizophrenia. We found that some areas are exposed to a risk of hospitalization for these diagnostic categories which is more than 50% above the reference. Contrary to other authors we did not identify an increased frequency of admission concentrated in the inner-city area for any of the diagnostic groups. The risk of hospitalization for schizophrenics was almost entirely associated with the close proximity of psychiatric units, while the risks for neuroses and personality disorders, as well as alcohol and drug abuse, appeared to be concentrated in areas of low social status. However, a statistically relevant correlation between an increased risk of hospitalization and low social status could be determined only for drug abuse and alcoholism. In the end, we did identify two areas in which there was an increased risk of hospitalization for several diagnostic groups, and this information will undoubtedly facilitate the planning of hospital and psychiatric services. The fact that our findings deviate to some extent from other authors – especially with respect to neuroses and personality disorders, but also to addiction – can be attributed to the inclusion of psychiatric cases from general hospitals in our geographic analysis.
Chagas disease (CD) is a neglected disease and endemic in Brazil. In the Brazilian Northeast Region, it affects millions of people. Therefore, it is necessary to identify the spatiotemporal trends of CD mortality in the Northeast of Brazil. This ecological study was designed, in which the unit of analysis was the municipality of the Brazilian northeast. The data source was the Information System of Mortality. It was calculated relative risk from socioeconomic characteristics. Mortality rates were smoothed by the Local Empirical Bayes method. Spatial dependency was analysed by the Global and Local Moran Index. Scan spatial statistics were also used. A total of 11 287 deaths by CD were notified in the study. An expressive parcel of this number was observed among 70-year-olds or more (n = 4381; 38.8%), no schooling (n = 4381; 38.8%), mixed-race (n = 4381; 62.3%), male (n = 6875; 60.9%). It was observed positive spatial autocorrelation, mostly in municipalities of the state of Bahia, Piauí (with high-high clusters), and Maranhão (with low-low clusters). The spatial scan statistics has presented a risk of mortality in 24 purely spatial clusters (P < 0.05). The study has identified the spatial pattern of CD mortality mostly in Bahia and Piauí, highlighting priority areas in planning and control strategies of the health services.
This study tests the use of a constrained nonnegative matrix factorization (NMF) algorithm to explore the comparatively new field of chemometric microscopy to support tissue diagnosis. The algorithm can extract the spectral signature and the absolute concentration map of endogenous fluorophores from wide-field microscopic images. The resultant data distinguished normal and fibrous calvarial tissues, based on the changes in their spectral signatures. The absolute concentration map of endogenous fluorophores, nicotinamide adenine dinucleotide (NADH), flavin adenine dinucleotide (FAD), and lipofuscin were derived from microscopic images and compared with the fluorescence from pure fluorophores. While the absolute concentration of NADH increased, the same of FAD and lipofuscin decreased from a normal to fibrous calvarial condition. An increase in the optical redox ratio, possibly due to the metabolic changes during the development of fibrosis, was observed. Differentiating tissue types using the absolute concentration map was found to be considerably more precise than that achievable with relative concentration. The quantification of fluorophores with reference to the absolute concentration map can eliminate uncertainties due to system responses or measurement details, thereby generating more biologically apposite data. Wide-field microscopy augmented with a constrained NMF algorithm could emerge as an advanced diagnostic tool, potentially heralding the emergence of chemometric microscopy.
The Upper Paleolithic open-air site Sungir is located in the central Russian Plain. The blank production of the lithic industry is characterized by parallel reduction with flakes being the main blank type. The tool assemblage has two components: archaic types (Mousterian-like) on the one hand and Upper Paleolithic types on the other. The available data does not allow for a confident determination of the chronological position of the Sungir site, nor does it enable researchers to distinguish different stages of human occupation. The horizontal distribution of the dated samples demonstrates the almost complete absence of radiocarbon (14C) dates for household features identified at the site (fireplaces, fire and ritual pits, large accumulations of bones, etc.). In addition, the vertical distribution of 14C dates in the rather thick cultural layer points to the exposure of the site to solifluction.
The eastern North Atlantic (ENA) has many highly productive areas where several species of cetaceans have been recorded, with the common dolphin (Delphinus delphis) being one of the most frequently sighted species. However, its spatial and temporal distribution in high seas is poorly known. The study presents the results from 5 years of cetacean monitoring in the ENA (2012–2016) aboard cargo ships that follow the routes from Continental Portugal to the Macaronesian archipelagos and north-west Africa. Common dolphin was the most frequently sighted cetacean with 192 occurrences registered on effort and an overall encounter rate of 0.36 sightings/100 nmi. The species was distributed in coastal and offshore waters, but absent from the Canaries and Cape Verde islands. Statistical ‘habitat’ models were developed to describe and explain the occurrence of sightings of the species: variables affecting detection of dolphins had a small impact and there were clear spatiotemporal distribution patterns, influenced to some degree by environmental variables. Predicted probability of occurrence was highest in coastal waters of continental Portugal and around the Azores. The models, combined with maps of distribution, were useful to identify important areas for the species, which could be the focus of future conservation efforts. Common dolphin presence was related to depth, distance to coast and seamounts, seabed slope, chlorophyll concentration, sea-surface temperature and sea level anomalies; the possible ecological significance of these relationships is explored.
The rain forests of South-East Asia represent a biodiversity hotspot of terrestrial leeches, but we have only fragmentary and often anecdotal information on this component of tropical communities. To address the foraging tactics of terrestrial leeches, we studied the vertical distribution of Haemadipsa picta on foliage in a Bornean tropical rain forest. We investigated the links between leech body length and the above-ground height of their ambush positions under natural conditions and in a choice experiment performed under semi-natural conditions. We studied 167 leeches, which varied considerably with respect to body length (4–29 mm). On average, the leeches ambushed at lower heights under natural conditions than under experimental conditions (47.7 cm vs. 67.5 cm), though the heights of ambush positions overlapped considerably. Leeches that chose higher ambush positions under natural conditions consistently chose higher ambush positions in the experiment (Pearson r = 0.29). Under both natural and experimental conditions, leech body length was positively correlated with the height of ambush positions (Pearson r = 0.48); on average, a 1-mm increase in body length corresponded to a 2–3 cm higher ambush position. Our findings suggest that H. picta individuals actively choose hunting locations according to their above-ground height, shifting their ambush sites over ontogeny to higher foliage. We hypothesize that growing leeches might target different prey following ontogenetic shifts in the foraging optima, ultimately decreasing intraspecific competition.
Toxoplasma gondii, a zoonotic parasite of global importance, infects all endothermic vertebrates, with extensive health implications. The prevalence of this parasite is seldom monitored in wildlife. Here, a semi-aquatic species, the Eurasian otter (Lutra lutra) was used as a model to assess the potential effect of climate, land cover and biotic factors on T. gondii seroprevalence in British wildlife. The Sabin–Feldman cytoplasm-modifying dye test identified T. gondii antibodies in 25·5% of blood samples from otters found dead, mainly as road kill, in England and Wales, between 2004 and 2010. Otters in the east of England were more likely to be infected with T. gondii than those in western regions. Land cover and temperature are key determinants of T. gondii infection risk, with more infection in arable areas and lower infection where temperatures are higher. The probability of T. gondii infection increased with host age, reflecting cumulative exposure with time, but there was no association between T. gondii seroprevalence and cause of host death.
When a range of weed densities is needed for competition experiments, one method of reducing existing populations is to remove all weeds in strips of specified length down the crop row. This technique also can be used to create different sizes of weed dusters. Two methods of sampling weed densities after such thinning were compared: unrestricted sampling (under which quadrats are placed randomly within the row) and restricted sampling (under which quadrats are randomly placed within a row under the restriction that they coincide with the beginning of an infested strip). The bias of estimators of weed density under each of these two approaches was derived and bias-corrected estimators of weed density from the two methods were compared on the basis of their variance. The variance under restricted sampling is less than or equal to the variance under unrestricted sampling so that, by a minimum variance criterion, restricted sampling using a bias correction is the better technique.