Hasil untuk "Natural history (General)"

Athanasios Gkanasos, Kostas Tsiaras, George Triantafyllou

This study presents the development of a three-dimensional, Wisconsin-type bioenergetic/population model, two-way coupled with a biogeochemical model (POM-ERSEM) that simulates physical, chemical, and biological processes in the marine environment, to investigate the dynamics of anchovy (Engraulis encrasicolus) and sprat (Sprattus sprattus)—the two most ecologically and economically significant fish species in the Black Sea. The model simulates key energetic processes, including growth and reproduction, and, in conjunction with the population module, it was used to estimate the two species biomass spatiotemporal variability. A long-term simulation over 1960–2020 period was performed, using ECMWF ERA5 atmospheric forcing. The model successfully reproduces the interannual variability in both species’ stocks and highlights the formation of distinct anchovy and sprat habitats. To explore the effects of atmospheric forcing, a perpetual simulation for the same period was conducted. The analysis reveals a negative correlation between sea surface temperature and anchovy biomass, primarily due to reduced adult weight and increased energetic demands, which negatively impact productivity. In contrast, sprat populations exhibit a positive response to warming, with increased survival rates across life stages despite a decline in egg productivity due to habitat limitations. Furthermore, the study examines the species responses to varying fishing pressure. While both species and especially sprat, are threatened by overfishing, they demonstrate rapid recovery rates, indicating susceptibility to effective management measures. These findings provide valuable insights into the sustainable exploitation of anchovy and sprat under changing climatic conditions, aiding in the development of adaptive fisheries management strategies.

Daeryul Kwon, Kyeong-Eun Yoo, Hyeonjin Cho et al.

Abstract Diatoms are microalgae with a significant ecological role as primary producers, contributing approximately 20% of global carbon fixation. They exhibit remarkable evolutionary success and biodiversity, with approximately 18,000 species identified globally, including 2,323 species reported in Korea. In this study, we identified 13 unrecorded diatom species from various freshwater environments in Korea, including rivers, streams, reservoirs, and lagoons. Among these, the genera Brachysira, Gomphonella, and Staurophora were recorded for the first time in Korea, expanding the national species list. The unrecorded species included 12 pennate diatoms (Adlafia multnomahii, Encyonema cespitosum, Placoneis symmetrica, Gomphonema incognitum, Rhoicosphenia baltica, Brachysira vitrea, Gomphonella fogedii, Hantzschia psammicola, Hyalosynedra laevigata, Pseudostaurosira parasitica, Tryblionella calida, and Staurophora amphioxys) and one centric diatom (Discostella lacuskarluki). Morphological and ultrastructural analyses were conducted using scanning electron microscopy to characterize these species. This research highlights the biodiversity of Korean diatoms and their potential applications in environmental monitoring and nanotechnology, contributing to the broader understanding of diatom taxonomy and ecology.

Zhang Qiyue

In April 2025, China acceded to the Agreement on Port State Measures, marking its active efforts in combating illegal, unreported, and unregulated fishing. This represents a significant initiative of China to protect the marine ecological environment, achieve sustainable development of fisheries, and deeply participate in global marine governance, while also indirectly responding to the constrains from the United States through its “Indo-Pacific Maritime Domain Awareness Partnership”. This manuscript employs dual perspectives from international relations and international law, along with research methods such as literature review, legal provision analysis, comparative analysis, and case study, to examine the positive impacts, risks, and challenges brought by China’s accession to the Agreement. The research result is that China’s accession to the Agreement enables it to enhance the effectiveness of combating IUU fishing, better protect marine biological resources and fishery resources, and is conducive to improving its international image. In order to better fulfill the international obligations, China needs to ensure the coordination of domestic laws such as the Fishery law with the Agreement, fulfill its responsibilities and obligations as a port State, flag State, and developing country, and strengthen port supervision and compliance capabilities. Meanwhile, China also faces risks such as insufficient law enforcement capacity and certain developed states’ discriminatory inspections against Chinese fishing vessels. The research concludes that China should coordinate domestic laws with the Agreement on Port State Measures and other relevant laws and regulations, complete the upgrading and transformation of its domestic fishery industry, fulfill its responsibilities as a port State, flag State, and contracting party, establish standardized law enforcement procedures, improve the capacity of supervision and law enforcement, enhance the institutionalization, informatization, and intelligentization of fishery management, and actively participate in regional and international fishery cooperation. This article further discusses the accession to the Agreement marks China’s transformation from a “rule adapter” to an “rule builder” in global fishery governance, providing a practical path for balancing domestic sustainable fishery development with participation in global governance and constructing a maritime community with a shared future.

Tomas Vanagunas, Hailey Dennis, Amy Talboy et al.

Sharla Sugierski, Chad Campbell, Emily R. Hall et al.

Microplastic pollution is ubiquitous in the oceans. However, little is known about the physiological impact of microplastics on corals, particularly under predicted future ocean conditions. This study investigated the individual impacts of microplastic exposure (MP) and predicted future ocean conditions [ocean acidification and warming (OAW)] as well as the combination of these stressors (OAW+MP) on the growth and physiology of Acropora cervicornis, a threatened Caribbean coral and its associated symbiont, Symbiodiniaceae. After 22 days, the OAW+MP treatment resulted in more pronounced physiological changes than either stressor individually or the control. OAW conditions alone had minimal impacts, despite A. cervicornis generally being sensitive to thermal stress. The OAW+MP treatment and the MP treatment also disrupted the host-symbiont relationship evidenced by the higher symbiont densities relative to the control and the OAW treatments. Additionally, the OAW+MP treatment resulted in lower chlorophyll a per symbiont cell. Microplastic handling is energetically costly, possibly leading to changes in host-symbiont signaling. Photosynthetic efficiency was only marginally lower in the OAW+MP treatment, and values did not indicate photosystem damage. Negative host health impacts were found with the OAW+MP treatment exhibiting lower skeletal growth compared to the control and lower host protein concentrations compared to the OAW treatment. These results indicate that although short term microplastic exposure alone may not pose a significant threat to coral health, when adding additional stressors, it can further threaten the health and recovery of this already vulnerable species.

Karen Stamieszkin, Nicole C. Millette, Jessica Y. Luo et al.

Aquatic ecologists are integrating mixotrophic plankton – here defined as microorganisms with photosynthetic and phagotrophic capacity – into their understanding of marine food webs and biogeochemical cycles. Understanding mixotroph temporal and spatial distributions, as well as the environmental conditions under which they flourish, is imperative to understanding their impact on trophic transfer and biogeochemical cycling. Mixotrophs are hypothesized to outcompete strict photoautotrophs and heterotrophs when either light or nutrients are limiting, but testing this hypothesis has been hindered by the challenge of identifying and quantifying mixotrophs in the field. Using field observations from a multi-decadal northern North Atlantic dataset, we calculated the proportion of organisms that are considered mixotrophs within individual microplankton samples. We also calculated a “trophic index” that represents the relative proportions of photoautotrophs (phytoplankton), mixotrophs, and heterotrophs (microzooplankton) in each sample. We found that the proportion of mixotrophs was positively correlated with temperature, and negatively with either light or inorganic nutrient concentration. This proportion was highest during summertime thermal stratification and nutrient limitation, and lowest during the North Atlantic spring bloom period. Between 1958 and 2015, changes in the proportion of mixotrophs coincided with changes in the Atlantic Multi-decadal Oscillation (AMO), was highest when the AMO was positive, and showed a significant uninterrupted increase in offshore regions from 1992-2015. This study provides an empirical foundation for future experimental, time series, and modeling studies of aquatic mixotrophs.

Qiying Yang, Weibin Zhong, Yaqian Jiao et al.

Cigarette butts (CBs) pollution is a critical global environmental issue, yet limited research exists on CBs pollution in both coastal and inland Chinese cities with varying development levels. This study investigated CBs occurrence, contamination, Cigarette Butts Pollution Index (CBPI), and heavy metal leakage in four cities. The results of CBs collected over multiple days revealed higher contamination levels in coastal city of Dalian (0.10 ± 0.03 CBs/m2), inland cities of Baoding (0.06 ± 0.02 CBs/m2) and Meizhou (0.07 ± 0.02 CBs/m2) compared to first-tier coastal city of Guangzhou (0.03 ± 0.02 CBs/m2). Patterns of CBs occurrence and CBPI varied across land usage and cities development level. SEM and EDS analysis identified microplastics and heavy metal particles released from CBs in water environments. ICP-MS detected a total of 629.7 μg/L of 14 heavy metals. Approximately 1.9 ± 0.9 g/km2 of heavy metals are leaked daily in Chinese cities due to CBs, posing a severe threat to soil and water safety given the indiscriminate disposal of CBs. This study offers scientific insights into CBs pollution and underscores the pressing need for effective measures to mitigate environmental hazards, particularly heavy metal and microplastics contamination released from CBs in China.

Thoß Andreas F.

Agenor Manoel da Silva Filho

Uma das mais bem sucedidas obras do campo da História das Ciências no Brasil, “A Matemática no Brasil” conquistou quatro edições ao longo de 30 anos. Um clássico que permanece atual graças a nova edição da Editora Blücher. A presente resenha destaca os pontos mais significativos da obra e suas características textuais e materiais, enfatizando a importância de reedições de trabalhos como este para a difusão do campo. 

Lukáš Likavčan

SETI is not a usual point of departure for environmental humanities. However, this paper argues that theories originating in this field have direct implications for how we think about viable inhabitation of the Earth. To demonstrate SETI's impact on environmental humanities, this paper introduces Fermi paradox as a speculative tool to probe possible trajectories of planetary history, and especially the "Sustainability Solution" proposed by Jacob Haqq-Misra and Seth Baum. This solution suggests that sustainable coupling between extraterrestrial intelligences and their planetary environments is the major factor in the possibility of their successful detection by remote observation. By positing that exponential growth is not a sustainable development pattern, this solution rules out space-faring civilizations colonizing solar systems or galaxies. This paper elaborates on Haqq-Misra's and Baum's arguments, and discusses speculative implications of the Sustainability Solution, thus rethinking three concepts in environmental humanities: technosphere, planetary history, and sustainability. The paper advocates that (1) technosphere is a transitory layer that shall fold back into biosphere; (2) planetary history must be understood in a generic perspective that abstracts from terrestrial particularities; and (3) sustainability is not sufficient vector of viable human inhabitation of the Earth, suggesting instead habitability and genesity as better candidates.

Tarun Kumar Lohani, Gordon Sigu, Nellie Oduor et al.

The site suitability assessment of Bamboo in Kenya was studied for diverse agroecological zones (AEZs) comprising one indigenous and fifteen exotic bamboo species in nine different AEZs of Kenya. Three bamboo clumps from each species that were at least five years old were assessed to accurately capture data on growth performance and yield. Soil samples collected at 0–30 cm depth from different areas varied considerably. The proportion of soil varied across the bamboo planting sites (F(1,11) = 24.94; p < 0.001), soil pH in the planting sites varied significantly (F(1,11) = 13.92; p < 0.001), and soil bulk densities had different results (F(1,11) = 13.92; p < 0.001). The lowest bulk density (0.61 ± 0.01) was recorded in Kakamega (UM1), while the highest (1.63 ± 0.01) was reported in Gede. Data on characteristics of clumps and internode length and wall thickness integrated through GenStat statistical software using ANOVA entail a huge variation in growth performance for each bamboo species across planting sites. Morphological characters were also studied in detail. The mean height, diameter, and stocking density were comparatively lower even in elevated zones that were only 200 m below its natural range. This resulted in an extremely low yield, which is not viable for economic investment. The species is unsuitable for plantation establishment outside its natural range of 2300 m–3200 m above the sea level (a.s.l.). Plantation below this range will not dissipate but will not attain a healthy growth. The primary use will be restricted for ornamental and conservation purposes such as scaffolding, roof construction, and fabrication of basic household furniture.

J. L. Hernández-Pastora

In the standard Einstein's theory the exterior gravitational field of any static and axially symmetric stellar object can be described by means of a single function from which we obtain a metric into a four-dimensional space-time. In this work we present a generalization of those so called Weyl solutions to a space-time-matter metric in a five-dimensional manifold within a non-compactified Kaluza-Klein theory of gravity. The arising field equations reduce to those of vacuum Einstein's gravity when the metric function associated to the fifth dimension is considered to be constant. The calculation of the geodesics allows to identify the existence or not of different behaviours of test particles, in orbits on a constant plane, between the two metrics. In addition, static solutions on the hypersurface orthogonal to the added dimension but with time dependence in the five-dimensional metric are also obtained. The consequences on the variation of the rest mass, if the fifth dimension is identified with it, are studied.

Francesca Marina Tavolaro, Zoe Woodgate, Chris Brown et al.

Abstract Farmers in developing countries often work in challenging environments with poor infrastructure, marginal agricultural potential, and limited economic opportunities. These challenges are exacerbated when wildlife impact human livelihoods. Here, we analyze data quantifying the type and frequency of human‐wildlife impacts within communal conservancies across Namibia and explore possible drivers of temporal and spatial variation of these data. A total of 112,165 human‐wildlife impacts were reported between 2001 and 2019 at the national level, with livestock depredation the most common. Marked regional variation was however evident with crop raiding and attacks on humans more prevalent in the mesic North‐East, and both livestock depredation and infrastructure damage highest in the arid north‐western regions. Elephant, jackal, hyena, cheetah, and leopard (in descending order) were the species most frequently linked to reported damage. Distance to the nearest protected area and river, terrain ruggedness, conservancy size, and annual rainfall (amongst others) all had a significant impact on both the distribution and extent of human‐wildlife impact reports. Reports did not vary significantly with years but were significantly influenced by average monthly rainfall. Understanding spatial and temporal patterns of human‐wildlife impacts at a national scale, in addition to their potential drivers, allows for the identification of conflict hotspots and the allocation of resources and expertise to mitigate them. Ultimately, mitigating negative interactions between people and wildlife will allow for the continued sharing of space and with that the sustainability of a model that has seen a dramatic increase in both the distribution and abundance of wildlife in Namibia.

Zdenka Křenová, Tomáš Janík, Dušan Romportl

Abstract Appropriate management of European spruce forests in this time of climate change is a significant challenge. Uniform principles of quality forest practice must be applied, essentially in forests that are valuable from a conservation point of view. However, this may be problematic in protected areas with mixed ownership and disparate priorities. Managerial decision‐making is often based on personal knowledge, previous experience, priorities other than conservation, or political influence. Clear management guidelines at the European and national levels are lacking in many protected areas. In this article, we use data from the Šumava NP to elucidate varied management approaches applied by state and private municipal owners in forests of high conservation value. We used high‐resolution aerial photographs to evaluate the effects of forest management practices applied, and compared the status of spruce habitats before and after a major windstorm and large‐scale bark beetle outbreak. We found that follow‐up forest management measures have significantly affected forests in the Šumava NP negatively. However, changes are not equally spread across the area of study, with forest ownership important for the type and intensity of changes. Kašperské Hory Municipality, managed their forests more as a productive commercial forest as contrasted to the state owned forest. We compare our findings with experiences from other Central European national parks with similar forest management challenges. Options for improving and unifying the management of conservation‐valuable forests held in state and private ownership are discussed in the conclusion. Wide political consensus and stability together with long‐term mutual trust and a willingness to collaborate among conservationists, forest managers and forest owners were recognized to be essential for the successful achievement of conservation goals.

Yanbin Fan, Zhifei Xu, Xing Li et al.

Congenital muscular dystrophy with early rigid spine, also known as the rigid spine with muscular dystrophy type 1 (RSMD1), is caused by SEPN1 mutation. We investigated the clinical manifestations, pathological features, and genetic characteristics of 8 Chinese RSMD1 patients in order to improve diagnosis and management of the disease. Eight patients presented with delayed motor development, muscle weakness, hypotonia, and a myopathic face with high palatine arches. All patients could walk independently, though with poor running and jumping, and most had a rigid spine, lordosis, or scoliosis. The symptoms of respiratory involvement were present early, and upper respiratory tract infections and pneumonia often occurred. Five patients had severe pneumonia, pulmonary hypertension, and respiratory failure. Lung function tests showed variable restrictive ventilation dysfunction. Polysomnography suggested hypoxia and hypoventilation. The serum creatine kinase (CK) level was normal or mildly increased. Muscle biopsy indicated chronic myopathic changes and minicores. Muscle magnetic resonance imaging (MRI) showed diffuse fatty infiltration of the gluteus maximus and thigh muscle. SEPN1 gene analysis revealed 16 compound heterozygous variants, 81.3% of which are unreported, including 7 exon 1 variants. Our study expands the spectrum of clinical and genetic findings in RSMD1 to improve diagnosis, management, and standards of care. SEPN1 mutations in exon 1 are common and easily missed, and exon 1 should be carefully analyzed when RSMD1 is suspected, which will provide valuable genetic counseling for the family and useful information for future natural history studies and clinical trials.

Jiaxiang Yang, Hanyuan Deng, Zikai Tang et al.

The zeroth-order general Randić index $R^{0}_{a+1}$ of an $n$-vertices oriented graph $D$ is equal to the sum of $(d^{+}_{u_i})^{a}+(d^{-}_{u_j})^{a}$ over all arcs $u_iu_j$ of $D$, where we denote by $d^{+}_{u_i}$ the out-degree of the vertex $u_i$ and $d^{-}_{u_j}$ the in-degree of the vertex $u_j$, $a$ is an arbitrary real number. In the paper, we determine the orientations of cacti with the maximum value of the zeroth-order general Randić index for $a\geq 1$.

You-You Hao, Zhuo-Yi Zhu, Zhuo-Yi Zhu et al.

Estuaries modify the concentration and composition of riverine nutrients and organic matter (OM), which eventually determine the riverine flux effect to coasts. Nutrients, organic carbon (OC), pigments, and amino acids (AAs) from the samples collected in the eutrophic Wenchang River Estuary (WRE) in China and the oligotrophic Krka River Estuary (KRE) in Croatia were analyzed in order to have a better understanding of how estuaries regulate terrestrial materials. We found a clear increase of dissolved inorganic nitrogen (DIN) concentration and its subsequent decrease due to the removal of DIN (over 100 μM) in the WRE, whereas DIN showed minor variation lengthwise in the KRE, i.e., with the salinity changes, ranging between 1.0 and 5.8 μM. The elevated algae-derived OC, dissolved organic nitrogen, and particulate AAs nitrogen suggest that the OM assimilation may explain approximately one-third of the DIN removal in the WRE, whereas in the oligotrophic KRE, such inorganic to organic transformation is not likely to be significant. Due to the prominent estuarine nitrogen removal/assimilation process, DIN/dissolved inorganic phosphorus (DIP) ratio was as high as 425 in the upper WRE under strong riverine influence, but it declined to as low as 5.4 at the mouth of WRE, that is even lower than DIN/DIP ratio at the mouth of oligotrophic KRE (12). When compared with other rivers worldwide, the Wenchang River showed high nutrients and organic carbon yields. Given the contrasting estuarine process (e.g., DIN removal) between the KRE and the WRE, apparent high nutrient yield from eutrophic rivers should be viewed with caution in ocean studies as the final impact to coastal zone could be similar to the oligotrophic rivers like the KRE.

Gabriela V. Moraes, Mary Colleen Hannon, Douglas M. M. Soares et al.

Bioluminescence is widespread throughout the phylum Annelida and occurs in terrestrial and marine lineages. Among marine taxa, bioluminescence has been documented in eight families and anecdotally reported in six additional families. Although new bioluminescent systems have been recently described in annelids, there are still many other families whose light emission mechanisms have not been sufficiently studied. Some of these include luminescent species belonging to the Polynoidae family, also known as scale worms, whose iterations of dorsal elytra (scales) have the ability to emit intense light when stimulated. Depending on the degree of stimulation, some polynoids can autotomize these luminous elytra and posterior segments, which could potentially give them an advantage in evading attacks by predators. It is believed that Polynoidae bioluminescence is associated with a membrane enzyme known as “polynoidin,” which was isolated during the early 1980s from Malmgrenia lunulata. However, the characterization and properties of this enzyme, as well as the chemical nature of its substrate or additional potential cofactors, have never been fully described and remain largely unknown. As such, this paper seeks to revisit previous research involving bioluminescence studies in Polynoidae, as well as the morphological, phylogenetic and ecological aspects related to this emission of light.

I. Belyaev, G. Carboni, N. Harnew et al.

In this paper we describe the history of the LHCb experiment over the last three decades, and its remarkable successes and achievements. LHCb was conceived primarily as a b-physics experiment, dedicated to CP violation studies and measurements of very rare b decays, however the tremendous potential for c-physics was also clear. At first data taking, the versatility of the experiment as a general-purpose detector in the forward region also became evident, with measurements achievable such as electroweak physics, jets and new particle searches in open states. These were facilitated by the excellent capability of the detector to identify muons and to reconstruct decay vertices close to the primary pp interaction region. By the end of the LHC Run 2 in 2018, before the accelerator paused for its second long shut down, LHCb had measured the CKM quark mixing matrix elements and CP violation parameters to world-leading precision in the heavy-quark systems. The experiment had also measured many rare decays of b and c quark mesons and baryons to below their Standard Model expectations, some down to branching ratios of order 10-9. In addition, world knowledge of b and c spectroscopy had improved significantly through discoveries of many new resonances already anticipated in the quark model, and also adding new exotic four and five quark states.

Grace Moore, Michael Tessler, Seth W. Cunningham et al.

Abstract Fossil rodent middens are powerful tools in paleoecology. In arid parts of western North America, packrat (Neotoma spp.) middens preserve plant and animal remains for tens of thousands of years. Midden contents are so well preserved that fragments of endogenous ancient DNA (aDNA) can be extracted and analyzed across millennia. Here, we explore the use of shotgun metagenomics to study the aDNA obtained from packrat middens up to 32,000 C14 years old. Eleven Illumina HiSeq 2500 libraries were successfully sequenced, and between 0.11% and 6.7% of reads were classified using Centrifuge against the NCBI “nt” database. Eukaryotic taxa identified belonged primarily to vascular plants with smaller proportions mapping to ascomycete fungi, arthropods, chordates, and nematodes. Plant taxonomic diversity in the middens is shown to change through time and tracks changes in assemblages determined by morphological examination of the plant remains. Amplicon sequencing of ITS2 and rbcL provided minimal data for some middens, but failed at amplifying the highly fragmented DNA present in others. With repeated sampling and deep sequencing, analysis of packrat midden aDNA from well‐preserved midden material can provide highly detailed characterizations of past communities of plants, animals, bacteria, and fungi present as trace DNA fossils. The prospects for gaining more paleoecological insights from aDNA for rodent middens will continue to improve with optimization of laboratory methods, decreasing sequencing costs, and increasing computational power.