Hasil untuk "Natural history (General)"

D. F. Lott

Xinyu Zheng, Yan Bai, Yan Bai et al.

IntroductionGlobal warming and glacier melt are transforming Southern Ocean ecosystems, profoundly affecting phytoplankton dynamics. This study investigates long-term phytoplankton changes in the Amundsen and Cosmonaut Seas, focusing on responses to climate-driven environmental shifts and the influence of the Southern Annular Mode (SAM).MethodsWe analyzed high-resolution (4 km, monthly averaged) satellite-derived chlorophyll-a (Chla) and net primary productivity (NPP) data from austral summers (2003–2020). Environmental parameters, including sea surface temperature (SST), photosynthetically active radiation (PAR) and wind speed (WS), sea ice concentration (SIC) and mixed layer depth (MLD), were examined to elucidate their roles in driving phytoplankton variability in the Amundsen and Cosmonaut Seas.ResultsDuring positive SAM phases, Chla and NPP generally increased across both seas, but local ocean circulation led to divergent subregional trends. North of the Southern Antarctic Circumpolar Front (sACCF) and within the Weddell Gyre, enhanced wind-driven MLD promoted Chla increases. In the northern Ross Gyre, cooling SST and deeper MLD intensified upwelling and nutrient, sustaining Chla growth, while shallower MLD and weaker upwelling in the eastern Ross Gyre reduced Chla. In coastal Amundsen Sea, warming SST facilitated sea ice melt, increasing Chla, whereas cooling SST in the Cosmonaut Sea and Prydz Bay increased SIC, reducing Chla.DiscussionThis high-resolution analysis highlights the complex interplay of physical and biological drivers in polar marine ecosystems, providing critical insights into climate change impacts on Southern Ocean phytoplankton dynamics and their regional variability.

Jianping Li, Gang Wang, Rujing Ren et al.

Background Social media listening is a new approach for gathering insights from social media platforms about users’ experiences. This approach has not been applied to analyse discussions about Alzheimer’s disease (AD) in China.Aims We aimed to leverage multisource Chinese data to gain deeper insights into the current state of the daily management of Chinese patients with AD and the burdens faced by their caregivers.Methods We searched nine mainstream public online platforms in China from September 2010 to March 2024. Natural language processing tools were used to identify patients and caregivers, and categorise patients by disease stage for further analysis. We analysed the current state of patient daily management, including diagnosis and treatment, choice of treatment scenarios, patient safety and caregiver concerns.Results A total of 1211 patients with AD (66% female, 82% aged 60–90) and 756 caregivers for patients with AD were identified from 107 556 online sources. Most patients were derived from online consultation platforms (43%), followed by bulletin board system platforms (24%). Among the patients categorised into specific disease stages (n=382), 42% were in the moderate stage. The most frequent diagnostic tools included medical history (97%) and symptoms (84%). Treatment options for patients with AD primarily included cholinesterase inhibitors, N-methyl-D-aspartate receptor antagonists and antipsychotics. Both quantitative and qualitative analysis of patients who experienced wandering (n=92) indicated a higher incidence of wandering during the moderate stage of the disease. Most caregivers were family members, with their primary concerns focusing on disease management and treatment (90%), followed by daily life care (37%) and psychosocial support (25%).Conclusions Online platform data provide a broad spectrum of real-world insights into individuals affected by AD in China. This study enhances our understanding of the experiences of patients with AD and their caregivers, providing guidance for developing personalised interventions, providing advice for caregivers and improving care for patients with AD.

Jose Carlos Báez

Teal A. Harrison, Ryutaro Goto, Jingchun Li et al.

Symbionts dominate planetary diversity and three primary symbiont diversification processes have been proposed: co-speciation with hosts, speciation by host-switching, and within-host speciation. The last mechanism is prevalent among members of an extraordinary marine symbiosis in the Indian River Lagoon, Florida, composed of a host mantis shrimp, Lysiosquilla scabricauda, and seven host-specific commensal vasconielline “yoyo” clams (Galeommatoidea) that collectively occupy two distinct niches: burrow-wall-attached, and host-attached/ectocommensal. This within-host symbiont radiation provides a natural experiment to test how symbiont coexistence patterns are regulated in a common ancestral habitat. The competitive exclusion principle predicts that sister taxa produced by adaptive speciation (with distinct morphologies and within-burrow niches) are most likely to coexist whereas the neutral theory predicts no difference among adaptive and non-adaptive sister taxa co-occurrence. To test these predictions, we engaged in (1) field-censusing commensal species assemblages; (2) trophic niche analyses; (3) laboratory behavioral observations. Although predicted by both models, the field census found no mixed-niche commensal assemblages: multi-species burrows were exclusively composed of burrow-wall commensals. Their co-occurrence matched random assembly process expectations, but presence of the single ectocommensal species had a highly significant negative effect on recruitment of all burrow-wall commensal species (P < 0.001), including on its burrow-wall commensal sister species (P < 0.001). Our stable isotope data indicated that commensals are suspension feeders and that co-occurring burrow-wall commensals may exhibit trophic niche differentiation. The artificial burrow behavioral experiment yielded no evidence of spatial segregation among burrow-wall commensals, and it was terminated by a sudden breakdown of the host-commensal relationship resulting in a mass mortality of all commensals unattached to the host. This study system appears to contain two distinct, superimposed patterns of commensal distribution: (1) all burrow-wall commensal species; (2) the ectocommensal species. Burrow-wall commensals (the plesiomorphic condition) broadly adhere to neutral theory expectations of species assembly but the adaptive evolution of ectocommensalism has apparently led to ecological exclusion rather than coexistence, an inverse outcome of theoretical expectations. The ecological factors regulating the observed burrow-wall/ectocommensal exclusion are currently obscure but potentially include differential recruitment to host burrows and/or differential survival in “mixed” burrow assemblages, the latter potentially due to changes in host predatory behavior. Resampling host burrows during commensal recruitment peak periods and tracking burrow-wall commensal survival in host burrows with and without added ectocommensals could resolve this outstanding issue.

Song Zhao, Long Wang, Lujie Song et al.

Accurate identification of coastal hyperspectral remote sensing targets plays a significant role in the observation of marine ecosystems. Deep learning is currently widely used in hyperspectral recognition. However, most deep learning methods ignore the complex correlation and data loss problems that exist between features at different scales. In this study, Multi-scale attention reconstruction convolutional network (MARCN) is proposed to address the above issues. Firstly, a multi-scale attention mechanism is introduced into the network to optimize the feature extraction process, enabling the network to capture feature information at different scales and improve the target recognition performance. Secondly, the reconstruction module is introduced to fully utilize the spatial and spectral information of hyperspectral imagery, which effectively solves the problem of losing spatial and spectral information. Finally, an adaptive loss function, coupling cross-entropy loss, center loss, and feature space loss is used to enable the network to learn the feature representation and improve the accuracy of the model. The experimental results showed that the effectiveness of MARCN was validated with a recognition rate of 96.62%, and 97.92% on the YRE and GSOFF datasets.

Edgar Karofeld, Kai Vellak, Arvo Tullus

Spontaneous revegetation of extracted peatlands is a very slow and sporadic process and, therefore, Sphagnum fragments cut from donor sites are often used for restoration. In two bogs in central and north-east Estonia, we studied the recovery and growth of Sphagnum fuscum, Sphagnum rubellum and Sphagnum medium after cutting of donor sites, in comparison with natural bog sites. On average, the water table was 13.8–17.4 cm higher in spring than in autumn, in both natural and donor sites, and mostly higher in the latter by 1.2–8.1 cm. Shoot length increment, density and weight of capitula of Sphagnum mosses were lower in the donor sites than in natural bog sites. The cover of Sphagnum mosses reached 5–50 % over a period of 3–11 years after cutting, indicating much slower recovery than has been reported previously. Of the Sphagnum species studied, S. fuscum showed better recovery in the donor sites. As the weather was similar in the natural and donor sites and the water table was mostly higher in the donor sites, the growth of Sphagnum mosses is most probably impeded by the combination of interrupted capillary water rise and a more pronounced drought effect in the donor sites. To promote revegetation of donor sites, plant fragments should be cut from the uppermost <10 cm only, and not from the entire area but instead leaving uncut patches or stripes to enable faster spreading of plants. Because of the slow recovery of donor sites, cutting of Sphagnum fragments from natural bogs should be avoided, and sites bordering expanding peat extraction areas should be chosen in preference.

Igor V. Karyakin, Elvira G. Nikolenko, Elena P. Shnayder

The range and abundance of Saker Falcon (Falco cherrug) in Russia and Kazakhstan are systematically declining. It is no exaggeration to say that the Saker Falcon is by far the most endangered raptor species in the Palaearctic. A compilation of literature data shows the species’ estimated abundance in 1970s Russia was at least 9,000–10,000 pairs (Galushin, 2004; Karyakin, 2008), while it appears over 15,000 pairs nested in Kazakhstan – in the 1990s their abundance there was estimated at 5,218 (4,808–5,628) pairs.

Shixuan Liu, Shixuan Liu, Shixuan Liu et al.

This research is motivated by the practical requirements in the sustainable deployment of ocean moored buoy observing networks. Ocean moored buoys play an important role in the global marine environment monitoring. Ocean buoy station layout planning is a typical multiple-objective spatial optimization problem that aims to reduce the spatial correlation of buoy stations and improve their spatial monitoring efficiency. In this paper, we develop a multi-objective mathematical model for allocating ocean buoy stations (MOLMofOBS) based on Tobler’s first law of geography. A spatial neighborhood model based on a Voronoi diagram is built to represent the spatial proximity of distributed buoy stations and delimit the effective monitoring region of every station. Then, a heuristic method based on a multiple-objective particles swarm optimization (MOPSO) algorithm is developed to calculate the MOLMofOBS via a dynamic inertia weight strategy. Meanwhile, a series of experiments is conducted to verify the efficiency of the proposed model and algorithms in solving single- and multiple-buoy station location problems. Finally, an interactive portal is developed in the Cyberinfrastructure environment to provide decision-making services for online real-time planning of the ocean buoy station locations. The work reported in this paper will provide spatial decision-making support for the sustainable development of ocean buoy observing networks.

Deepti M. Patel, Monica F. Brinchmann, Anna Hanssen et al.

Lumpfish (Cyclopterus lumpus L) is a North Atlantic species harvested for its roe and increasingly used as a cleanerfish in Atlantic salmon (Salmo salar L.) farming to remove salmon louse (Lepeophtheirus salmonis). In aquaculture, the health and welfare of fish depends on optimal levels of several biotic and abiotic factors. Crowding, a common abiotic stress factor in aquaculture practice, can affect the welfare and survival of fish. In this study, lumpfish was exposed to crowding stress daily at random timepoints for one month (stress group) or no crowding (control group). Blood and skin were sampled weekly for physiological parameter analysis and proteomics, respectively. Adrenocorticotropic hormone (ACTH) stimulation and dexamethasone (DEX) suppression test were conducted at the sampling timepoints. Gel-based proteomics coupled with liquid chromatography and tandem mass spectrometry (LC-MS/MS) was used to identify protein changes in skin tissues of lumpfish under crowding. The results indicated that the stress group showed signs of allostatic overload type 2 (chronic stress) due to oversensitivity to ACTH, and a reduced negative feedback system with increased baseline levels of cortisol. These chronic changes in the endocrine system promoted changes in secondary and tertiary stress responses as reduced osmoregulatory capacity and stunted growth, after 14 days of stress and onward. Calmodulin, guanine nucleotide binding protein subunit beta 2, glutathione-S-transferase Mu 3, fatty acid binding protein, heat shock cognate 70 kDa protein, keratin, histone H4 and 14-3-3 alpha/beta showed protein spot intensity changes compared with controls in lumpfish skin at one or several time points during the one month period of crowding stress. The differentially expressed proteins are related to several metabolic pathways and are involved in stress and immune responses. Overall, the study shows that lumpfish can suffer from chronic stress with possible dire consequences for the animal welfare.

Violetta V. Molchanova

Explanation. The tourism industry, its functioning and development depend on many factors. One of them is natural-geographical. What natural resources a region has will determine its touristical policy. It can also be noted that the tourism industry is usually considered in terms of infrastructure, culture and politics. The natural and geographical factor is considered secondary or it considered schematically. The purpose of the study is to identify and characterize the natural and geographical factors, to analyze how in practice they affect to the tourism industry of the Astrakhan region. Methods. The research was conducted on the basis of several methods. These are analytical, comparative, method of induction, structural and functional, the method of analysis of sources. It allowed to consider the factors from different points of view.Documents from the State Archives of the Astrakhan Region were examined. Sectoral target programs dedicated to the development of tourism in the Astrakhan region were studied. Results. Natural and geographical factors affecting the tourism industry in general and the Astrakhan region in particular were identified. Theses put forward in the beginning of the article (influence of nature and geography on tourism) were confirmed, both in theory and in practice. Scope of application of the results. Materials of work can be used in various areas of knowledge. It is history, tourism, ecology. The results of the work can be used in the research of geographical science. Both the history of the region and local history can be added to this list.

Liu Lihong, Jiang Peng, Wen Yongshuai

[Objective] The influence of water-related structures on the flood routing process before and after structure construction was analyzed to provide scientific supports for the real and efficient calculation of bridge engineering in flood storage and detention areas, and for the effective development of flood control in flood storage areas. [Methods] The Mengwa flood storage area in Fuyang City, Anhui Province was selected as the study area. Based on the latest data of regional topography, hydrological data, and bridge engineering design, the unstructured hydrodynamic model of MIKE 21 was used to simulate the flood evolution process of the Mengwa flood storage area in real time. The influence of bridge construction on flood evolution time, velocity distribution, and water level change in the flood storage and detention area was analyzed. [Results] After the construction of the bridge project, the flood-splitting time near the bridge position was 45 s behind the maximum lag before the construction of the project; the flow rate distribution range of the mainstream area was 0.4 to 0.6 m/s; the local velocity change rate was 7.409%; the maximum elevation value of the water level near the bridge was 0.006 m; and the maximum change rate of the water level was -0.22‰. [Conclusion] Bridge construction delayed the flooding time in the flood storage area, raised the water level near the pier, and changed the distribution of the flow rate near the project. However, the overall impact on the flood storage area was small, and basically did not affect the normal operation of the flood storage area.

Chengcheng Shen, Chengcheng Shen, Hong Cheng et al.

Hexactinellid sponges often form structural habitats for other organisms and thus support high biodiversity. Two representative morphotypes of hexactinellid sponges were sampled by a remotely operated vehicle along a transect (depths of 2377–2758 m) on the Ko-Hakucho Guyot in the northwestern Pacific Ocean, both new to science. One new species, Flavovirens hemiglobus gen. et sp. nov., which is pedunculate and bears the main choanosomal spicules of diactins, is clearly attributed to the euplectellid subfamily Bolosominae. Its set of microscleres present (namely, predominating oxyhexasters and discasters, and rare discohexasters and staurodiscs) characterizes it as a new genus. The other new species, Chonelasma tyloscopulatum sp. nov., which is funnel in form without dichotomous branching tubes or lateral oscula and has firm body walls supported by a three-layered dictyonal framework, is clearly attributed to the euretid genus Chonelasma (subfamily Chonelasmatinae). Its presence of surface pentactins, two types of scopules, and both oxy- and disco-tipped hexasters or hemihexasters as common microscleres, characterizes it as a new species. The placements are also supported by molecular phylogenetic evidence from nuclear 18S rDNA and 28S rDNA, and mitochondrial 16S rDNA and cytochrome c oxidase subunit I (COI) gene. More sampling efforts should be conducted to improve the understanding of the biodiversity of deep-sea seamount sponges.

J. D. Prown

M. Mont, J. Carbone, A. Fairbank

Areeruk Nilsai, Matsapume Detcharoen, Nerivania Nunes Godeiro et al.

Four new species of troglomorphic Coecobrya Yosii, 1956 are described from caves located in the central and northeastern regions of Thailand. Coecobrya whitteni sp. nov. and C. troglobia sp. nov. are from Khon Kaen province, C. ellisi sp. nov. is from Phetchabun province and C. phitsanulokensis sp. nov. is from Phitsanulok province. They all exhibit remarkable troglobitic characters i.e. elongated antennae, legs and furca, slender claw complex and large body size. Coecobrya whitteni sp. nov. is similar to C. troglobia sp. nov. and they were found a distance of only 3.4 km from each other. However, they are mainly different in the number of An mac on dorsal head and number of chaetae of Th. II. Likewise, C. ellisi sp. nov. is similar to C. phitsanulokensis sp. nov.. However, they differ in the number of An mac on the dorsal head, the number of central mac on Abd. II, central mac on Abd. IV, lateral mac on Abd. IV and the number of inner teeth of the claw. Moreover, C. ellisi sp. nov. has orange pigment dots on the body, a unique character, considering that all other troglomorphic Coecobrya species in Thailand are devoid of pigmentation. The results of the molecular approach based on two partial mitochondrial markers (COI and 16S rDNA) and a nuclear gene fragment (28S rDNA) supported the results of morphological species discrimination in separating the four nominal populations as valid species. An updated dichotomous key of Thai troglomorphic Coecobrya species is also given.

Miguel Agulles, Miguel Agulles, Gabriel Jordà et al.

The fate of the beaches around the world has paramount importance as they are one of the main assets for touristic activities and act as a natural barrier for coastal protection in front of marine storms. Climate change could put them at risk as sea levels rise and changes in the wave characteristics may dramatically modify their shape. In this work, a new methodology has been developed to determine the flooding of sandy beaches due to changes in sea level and waves. The methodology allows a cost-effective and yet accurate estimation of the wave runup for a wide range of beach equilibrium profiles and for different seagrass coverage. This, combined with regional projections of sea level and wave evolution, has allowed a quantification of the future total water level and coastline retreat for 869 beaches across the Balearic Islands for the next decades as a function of greenhouse gases emission scenario. The most pessimistic scenario (RCP8.5) at the end of the century yields an averaged percentage of flooded area of 66% under mean conditions which increases up to 86% under extreme conditions. Moreover, 72 of the 869 beaches of the region would permanently disappear while 314 would be completely flooded during storm episodes. Under a moderate scenario of emissions (RCP4.5), 37 beaches would permanently disappear while 254 would disappear only during storm episodes. In both cases, the average permanent loss of beach surface at the end of the century would be larger than 50%, rising over 80% during storm conditions. The results obtained for the Balearic Islands can be extrapolated to the rest of the Mediterranean as the beaches in all the regions have similar characteristics and will be affected by similar changes in sea level and wave climate. These projections indicate that adaptation plans for beach areas should be put in place as soon as possible.

Susan C. Trapp, R. Croteau

Anja F. Köhn, Lorenz Grigull, Marcel du Moulin et al.

Background: Mucopolysaccharidosis type IIIA (MPS IIIA, Sanfilippo A syndrome) is a chronic progressive neurodegenerative storage disorder caused by a deficiency of lysosomal sulfamidase. The clinical hallmarks are sleep disturbances, behavioral abnormalities and loss of cognitive, speech and motor abilities. Affected children show developmental slowing from the second year of life, dementia occurs by the age of 5 years followed by death in the second decade of life. Only a few studies concerning HSCT in MPS IIIA have been published and do not document a clear benefit of treatment. Methods: The present study summarizes the clinical outcome of a girl with MPS IIIA who received HSCT at the age of 2.5 years. Her clinical course was compared with the natural history of six untreated MPS IIIA patients carrying the same mutations (p.R74C and p. R245H) in the SGSH-gene. Results: Eight years after successful HSCT, the patient showed a global developmental delay. However, cognitive abilities continued to develop, albeit very slowly. There was no sign of regression. She could talk in short sentences, had good motor abilities and performed basic daily living activities by herself. She did not present with sleeping problems, but behavioral abnormalities were profound. In contrast, the six untreated patients with identical mutations in the SGSH-gene showed the typical progressive course of disease with early and continuous loss of abilities. Conclusions: The present data suggest a beneficial effect of HSCT performed at an early stage of MPS IIIA on cognitive skills, motor function and quality of life.

Sai Sein Lin Oo, Myint Kyaw, Nay Myo Hlaing et al.

Rosy Starlings Pastor roseus are a widespread species in Europe and Central Asia, have been found in southern Southeast Asia but hardly on passage so far. Here we report a first record of Rosy Starlings from Myanmar, in the Hkakabo Razi Landscape.