Patterns Of Occurrence Research Articles

The environmental impact of the feral pigeon (Columba Livia f. Domestica) in the historic city centre of Sopron

The presence of different bird species in inhabited areas is becoming increasingly common. The problem with these species is that they are more likely to spread pathogens, contaminate public and private land with their droppings, cause economic damage or even frighten the public. One of the most notable conflict species causing environmental pressures in populated areas is the feral pigeon (Columba livia f. domestica), whose populations are increasing worldwide. Adequate practices and methods are available to reduce the problem. However, their applicability and effectiveness may vary from one locality to another due to the different characteristics of the localities and the different causes of the pigeons' presence. Therefore, it is essential to think in terms of town-specific solutions, the preparation of which requires, among other things, an assessment of the temporal and spatial pattern of occurrence of the species causing the conflict, an understanding of the extent of damage and an overview of the population's level of information. In our study, we investigated the environmental pressures of the feral pigeon in the historical city centre of Sopron, using a combination of the three elements mentioned above. For this purpose, we carried out a monthly visual population assessment combined with a photographic technique at sample points for one year. We conducted a field visit to the area to draw up a damage map of the study area and a spatial localisation of existing control methods. Questionnaire surveys complemented this to assess the public's awareness of the issue. In light of the results, we drew up a map of the pigeon conflict in the city centre of Sopron and identified possible solutions.

Contemporary community composition, spatial distribution patterns, and biodiversity characteristics of zooplankton in large alpine Lake Sevan, Armenia

We studied the quantitative composition, spatial distribution, and temporal dynamics of the zooplankton community of the alpine Lake Sevan, Armenia, the largest surface water in the Caucasus region. This article is providing a long-term information and fills the research gap of multiyear data on zooplankton, as the previous research on zooplankton provided only snapshots of the community, and a consistent assessment over multiple years was missing. However, an initial mini-review of historical studies indicated that zooplankton biomass and fish abundance were undergoing large fluctuations, indicating the importance of top-down control. We analysed 239 samples from the period 2016-2019 from 32 sampling sites in Lake Sevan and recorded 37 species of meso- and macrozooplankton (Rotifers, Copepods, Cladocera). Biomass fluctuations were high with peaking biomasses in 2016 and lowest biomasses in 2018, yearly averaged biomass varied about one order of magnitude. Variability over time was hence much higher than spatial variability. The pelagic habitat at the deepest part of the lake showed the highest diversity and biomasses but contrasts between sampling sites remained smaller than changes from year to year or seasonally. Many samples were dominated by a single species, and these key species explain observed biomass dynamics to a wide extent. We applied hierarchical clustering in order to identify phenological groups that appear to show similar patterns of occurrence. This clustering resulted in 6 groups where of 5 groups just consisting of one single species and these 5 key species were the Cladocerans Daphnia magna, Daphnia hyalina, Diaphanosoma sp. as well as the calanoids Arctodiaptomus bacillifer and Acanthodiaptomus denticornis. The most important species in Lake Sevan’s zooplankton during the observation period was D. magna, which reached high biomasses in 2016 and 2017 but then suddenly almost disappeared in 2018 and 2019. When there were more D. magna present, the water became clearer, which was measured using Secchi depth. This shows that these large water fleas effectively controlled the amount of phytoplankton in the water. Daphnia magna, in turn, managed to dominate zooplankton community only during times of extremely low fish biomass indicating strong top-down control of this large Cladoceran by fish. Both observations together imply a strong trophic linkage between fish, zooplankton, and phytoplankton and provide evidence for trophic cascades in Lake Sevan. Besides the novel insights into zooplankton community dynamics of this unique lake of high socio-economical, cultural, and ecological importance, our study also points to potential management opportunities for eutrophication control by biomanipulation, as well as our investigation allows us to conclude that probably biotic factors were more important than abiotic factors in explaining the observed changes and dynamics within the plankton community.

Relationship between Summer Synoptic Circulation Patterns and Extreme Precipitation in Northern China

Synoptic circulation patterns over the midlatitudes play a pivotal role in regional precipitation changes; however, the synoptic circulation patterns over eastern Asia (35°–60° N, 105°–145° E) and their effects on extreme precipitation events in the North China Plain (NCP) and northeastern China (NEC) remain unclear. The summer daily 500 hPa geopotential height anomaly fields for 1979–2021 are classified into six synoptic circulation patterns using self-organizing map (SOM) cluster analysis. The SOM1 pattern, characterized by a high-pressure ridge over the north of eastern Asia and a trough near the Korean Peninsula, yields decreased precipitation in NEC. The SOM2 pattern reveals a robust high ridge over eastern Asia, resulting in a higher incidence of regional extreme precipitation events (REPEs) of approximately 24% in the NCP. Under the SOM3 pattern, the anomalous cyclonic circulation over eastern Asia leads to above-average precipitation in the NCP. The SOM4 pattern yields the highest incidence of REPEs in NEC, with the lowest incidence of REPEs in the NCP, as the anomalous cyclonic circulation over eastern Asia moves southeastward compared to the SOM3 pattern. The SOM5 pattern presenting an anticyclone–cyclone dipole reduces precipitation in the NCP and NEC, and the anticyclonic circulation near eastern China associated with the SOM6 pattern causes above-average precipitation in the NCP. On interannual time scales, the SOM2 pattern occurrence with an increasing trend tends to induce an increasing summer precipitation trend in the NCP. The SOM3 pattern occurrence is negatively correlated with the summer precipitation in NEC. Overall, classifying the synoptic circulation patterns helps to improve precipitation forecasting and provides insights into the synoptic circulation patterns dominating the occurrences of REPEs.

Effective thermal conductivity for hydrate-bearing sediments under stress and local thermal stimulation conditions: A novel analytical model

The extraction of hydrates is accompanied by changes in the hydrate occurrence pattern, hydrate saturation, effective stress, temperature, and pore structure in porous sediment, making it difficult to predict the effective thermal conductivity (ETC) of hydrate-bearing sediments. Until now, accurately modeling the ETC of gas hydrate sediments during the exploitation process has remained a significant challenge. In this study, by combining pore compression theory, and particle thermal expansion theory, an analytical ETC model is derived to study the physical relations between the ETC of hydrate-bearing sediments under excess water or excess gas condition and various influencing parameters (e.g., hydrate occurrence pattern, effective stress, hydrate saturation, pore structure, and temperature). The proposed model is validated against test data. Furthermore, the effects of pore structures (e.g., initial porosity and radius fluctuation amplitude), effective stress, hydrate saturation, and hydrate occurrence pattern on ETC are revealed. Compared with the existing ETC models of hydrate-bearing sediments, our derived model takes more mechanisms into account, which makes our derived model more reasonable. In short, this model is of great significance to predict ETC and study the heat transfer in gas hydrate reservoirs, enabling engineers and scientists to have a better understanding of the hydrate exploitation process.

Occurrence patterns and trends of cetaceans in the coastal waters of the Sea of Okhotsk and the Nemuro Strait, Hokkaido, Japan

Occurrence patterns and trends of cetaceans in the coastal waters of the Sea of Okhotsk and the Nemuro Strait, Hokkaido, Japan

Experimental evidence of mate choice as the driving mechanism behind negative assortative mating for shell colour in a marine snail

Abstract How colour polymorphisms are maintained in natural populations constitutes a key subject of study for evolutionary ecologists. One of the mechanisms that has been put forward to explain this phenomenon is negative frequency-dependent selection, which can be caused by different mechanisms. Among these mechanisms is mate choice, or the selection as a potential mate of the rare or dissimilar colour morph by the choosy sex of a given species. In the context of colour polymorphism, mate choice predicts the occurrence of a negative assortative mating pattern, whereby different colour morphs mate more often than expected by chance alone. However, negative assortative mating can also result from other mechanisms, making it, at best, a fallible indicator of a mate choice-driven negative frequency-dependent selection. For this reason, experimental evidence explicitly connecting such a mating pattern to mate choice is necessary to claim that a particular colour polymorphism is being maintained by negative frequency-dependent selection. Here we present experimental evidence backing this relationship for the colour polymorphic marine gastropod Littorina saxatilis from the Ría de Vigo (NW Iberian Peninsula), although how specifically these organisms choose their mates remains unclear. This calls for further experimental efforts to clarify this issue and its relationship to the maintenance of colour polymorphism in L. saxatilis.

Neural signatures of automatic repetition detection in temporally regular and jittered acoustic sequences.

Detection of repeating patterns within continuous sound streams is crucial for efficient auditory perception. Previous studies demonstrated a remarkable sensitivity of the human auditory system to periodic repetitions in unfamiliar, meaningless sounds. Automatic repetition detection was reflected in different EEG markers, including sustained activity, neural synchronisation, and event-related responses to pattern occurrences. The current study investigated how listeners' attention and the temporal regularity of a sound modulate repetition perception, and how this influence is reflected in different EEG markers that were previously suggested to subserve dissociable functions. We reanalysed data of a previous study in which listeners were presented with sequences of unfamiliar artificial sounds that either contained repetitions of a certain sound segment or not. Repeating patterns occurred either regularly or with a temporal jitter within the sequences, and participants' attention was directed either towards the pattern repetitions or away from the auditory stimulation. Across both regular and jittered sequences during both attention and in-attention, pattern repetitions led to increased sustained activity throughout the sequence, evoked a characteristic positivity-negativity complex in the event-related potential, and enhanced inter-trial phase coherence of low-frequency oscillatory activity time-locked to repeating pattern onsets. While regularity only had a minor (if any) influence, attention significantly strengthened pattern repetition perception, which was consistently reflected in all three EEG markers. These findings suggest that the detection of pattern repetitions within continuous sounds relies on a flexible mechanism that is robust against in-attention and temporal irregularity, both of which typically occur in naturalistic listening situations. Yet, attention to the auditory input can enhance processing of repeating patterns and improve repetition detection.

Pattern of Occurrence and Management of Dual Malignancy: Our Institutional Experience

Background: Management of dual malignancies is challenging in the present scenario of advanced techniques and increased life expectancy. Objectives: To determine the demographic and clinical profile of patients with dual malignancies and the management received. Methods: In this retrospective analysis of the data of patients presenting with histologically proven synchronous or metachronous dual malignancy, we evaluated the demographic and clinical profile of patients with dual malignancies and the management received. Results: In this study, 158 cases with multiple primary cancers, of whom 57 were synchronous and 101 were metachronous, were observed from January 2017 to December 2021. The maximum period for synchronous tumor occurrence was seen at 6 months (180 days). The interval of occurrence of metachronous tumors ranged from 1 to 15 years, with an average of 4.8 years for the entire group. Moreover, 73 (46.2%) were females, and 85 (53.8%) were males, with a male-to-female ratio of 1.2: 1. The most common site of primary tumor with dual malignancies was the head and neck (31%), followed by breast cancers (21%). The most frequent pathologic type was adenocarcinoma (40%), followed by squamous carcinoma (38%), hematopoietic and lymphoid tissues (7.5%), transitional cell carcinoma (6.3%), sarcomas and soft tissue tumors (2.5%). Conclusions: Even in complete clinical remission, every cancer patient must take into account the possibility of developing a second malignancy and must be closely monitored.

Large monitoring datasets reveal high probabilities for intermittent occurrences of pesticides in European running waters

Many studies have investigated short-term peak concentrations of pesticides in surface waters resulting from agricultural uses. However, we lack information to what extent pesticides reoccur over medium (> 4 days) and longer time periods (> 10 days). We use here large-scale pesticide monitoring data from across Europe (~ 15 mil. measurements, i.e., quantified concentrations in water at > 17,000 sites for 474 pesticide compounds) to evaluate the degree to which pesticides were not only detected once, but in sequences of a compound repeatedly quantified in the same area (0.015 km2) within 4–30 days. Reoccurrence was observed at ~ 18% of sites for > 76% of compounds, ~ 40% of which not a priori considered to chronically expose aquatic ecosystems. We calculated a probability of reoccurrence (POR) over medium-term (4–7 days) and long-term (8–30 days) time periods for ~ 360 pesticides. Relative PORs (ratio between long-term and medium-term POR) revealed three occurrence patterns: ephemeral, intermittent and permanent. While fungicides dominated intermittently occurring substances, aligning with application strategies and physico-chemical properties, neonicotinoids and legacy pesticides were among substances permanently occurring. The results of this study shed new light on previously underestimated longer-term occurrence of many pesticides in aquatic environments (35% of investigated substances occurring intermittently or permanently were previously not considered to pollute the aquatic environment chronically), entailing new challenges for chronic risk assessments and the evaluation of pesticide effects on aquatic biodiversity.

Rare plant species occurrence patterns are associated not with soil properties, but with frequent fire in a southeast Australian dry sclerophyll forest

AbstractQuestionSoil properties can play a crucial role in influencing the abundance and distribution of plant species. Fire regimes can also have substantial impacts on plant community composition. However, few studies have examined the effects of both fire regimes and soil properties on the occurrence of rare plant species. Here, we asked if rare species have specific soil and fire regime associations relative to common species, and if soil properties may explain potential fire effects.LocationBooderee National Park, southeastern Australia.MethodsWe collected soil cores and completed vegetation surveys on 42 sites in Sydney Coastal Dry Sclerophyll Forest vegetation. We tested for associations between the number of rare species and common species present in relation to three soil chemical properties (available phosphorus, ammonium and organic carbon), fire frequency, and time since fire.ResultsWe found that rare and common species were not associated with any of the examined soil properties. However, rare species were associated with sites with a high fire frequency, while common species were negatively associated with time since fire.ConclusionsOur results indicate that rare species’ occurrence patterns may be influenced by the direct effects of fire or mediated by multiple factors, rather than shaped solely by soil properties in our study area. Future work to understand the factors that underpin rare species’ occurrence patterns in response to fire is critical to develop fire management protocols that effectively conserve rare species in dry sclerophyll forests.

Fingerprint patterns in relation to an altered neurodevelopment in patients with autism spectrum disorder

AbstractDermatoglyphic patterns are permanently established and matured before the 24th week of gestation. Their frequencies and localization might be a good indicator of developmental instability in individuals with an altered neurodevelopment and show potential as biomarkers of autism spectrum disorder (ASD). In this study, fingerprint pattern counts and fluctuating asymmetry in the distribution of patterns are compared between 67 boys diagnosed with ASD (aged 5.11 ± 2.51 years) and 83 control boys (aged 8.58 ± 3.14 years). Boys with ASD had a higher rate of discordance in their fingerprint patterns (p = .0026), showing more often bilateral differences in the occurrence of certain patterns. A chi‐square test revealed that the difference in pattern frequencies between boys with ASD and the control group is the most significant in frequencies of whorls, tented arches, and ulnar loops. Boys with ASD have significantly fewer ulnar loops, significantly more whorls, and tented arches in the right hand. The achieved results are in favor of the suggestion that prenatal influences, which play a role in the development of bilateral differences in fingerprint patterns up to the 24th week of gestation, may be a potential cause of an altered neurodevelopment in ASD individuals.

Combining large-scale investigation and quantum chemical calculation of pharmaceuticals: Spatiotemporal patterns of occurrence and structural insights into removal

This study investigated the spatiotemporal distribution of 17 pharmaceuticals in wastewater treatment plants (WWTPs) from 17 provinces across China, and explored structural insights into their removal in full-scale wastewater treatment processes by quantum chemistry. Briefly, 10 pharmaceuticals were detected in above 85 % of samples, of which ibuprofen and sulfamethoxazole dominated with concentrations up to the μg/L level. Seasonally, concentrations of psychoactive drugs (PDs) were 1.3–2.6 times higher in summer than in other seasons. Spatially, higher average concentrations were detected in northern WWTPs, and regions with similar economic levels exhibited similar contamination patterns. Pharmaceutical removal in WWTPs ranged from 41.4 % (carbamazepine) to 87.2 % (sulfamethizole), with the secondary treatment segment, especially aerobic treatment units, maintaining an important position. Molecular structural mechanisms behind these removal performances were further revealed. Firstly, we demonstrated a significant association of pharmaceutical overall removal with electrophilicity index (ωcubic) as well as the lowest unoccupied molecular orbital energy (ELUMO). Highly electrophilic pharmaceuticals may persist in WWTPs and their sensitivity to electron exchange reactions accounted for the discrepant removal. In terms of treatment segments, pharmaceuticals with reaction sites masked in molecular structure, such as ibuprofen and venlafaxine, showed a propensity for tertiary treatment suitability. Furthermore, enzymes of aerobic units exhibited excellent docking affinity to pharmaceutical molecules with an average affinity of −7.2 kcal/mol, and hydrogen-bond interactions played an important factor in promoting biodegradation. Our results emphasize the necessity of assessing pharmaceutical contamination on a larger spatiotemporal scale. Moreover, the structural insights into removal phenomena offer scientific molecular-level justification for the design and optimization of pharmaceutical treatment technologies in WWTPs.

Overview of Balaenoptera whales strandings in Southern Brazil from 1993 to 2018

The ecology and distribution of most baleen whales are poorly known in Brazilian waters, despite the history of whaling and the recent increase in the research effort. Although stranding data presents some caveats, it is useful to understand patterns of distribution and occurrence and to detect population trends. In this scenario, data from 25 years of a monitoring marine mammal stranding program were used to evaluate the composition and spatial-temporal patterns of Balaenoptera whales in southern Brazil. A stretch of 270 km on the coast of Rio Grande do Sul State (from 29°20’S to 31°21’S) was surveyed year-round between 1993 and 2018. Whales were identified, measured and sex determined whenever possible. Molecular identification through mtDNA analysis was obtained for 22 individuals and confirmed field identification in 17 cases. Forty-eight whales of four species were recorded: common minke whale B. acutorostrata n = 27, Antarctic minke whale B. bonaerensis n = 1, Bryde’s whale B. brydei n = 13, fin whale B. physalus n = 1. In addition, six whales were not identified at species level due to advanced decomposition. The larger number of strandings of common minke and Bryde’s whales may be related to their greater abundance and/or more coastal distribution. Both species were recorded year-round, but strandings of common minke and Bryde’s whales occurred mostly during winter/spring (77.77%) and spring/summer (66.66%), respectively. Although Bryde’s whales appear to remain in southern Brazilian waters during the entire year, the results suggest the existence of seasonal inshore-offshore movements. Moreover, the greater number of strandings of juveniles of common minke whales compared to adults (ratio 1.86:1) and their occurrence in different seasons suggest that some immature individuals may not leave this region, as previously pointed out by other studies. This long-term survey brings new evidence of the importance of this region in the Southwestern Atlantic Ocean for some Balaenoptera species.

Frequency dependent whole-brain coactivation patterns analysis in Alzheimer's disease.

The brain in resting state has complex dynamic properties and shows frequency dependent characteristics. The frequency-dependent whole-brain dynamic changes of resting state across the scans have been ignored in Alzheimer's disease (AD). Coactivation pattern (CAP) analysis can identify different brain states. This paper aimed to investigate the dynamic characteristics of frequency dependent whole-brain CAPs in AD. We utilized a multiband CAP approach to model the state space and study brain dynamics in both AD and NC. The correlation between the dynamic characteristics and the subjects' clinical index was further analyzed. The results showed similar CAP patterns at different frequency bands, but the occurrence of patterns was different. In addition, CAPs associated with the default mode network (DMN) and the ventral/dorsal visual network (dorsal/ventral VN) were altered significantly between the AD and NC groups. This study also found the correlation between the altered dynamic characteristics of frequency dependent CAPs and the patients' clinical Mini-Mental State Examination assessment scale scores. This study revealed that while similar CAP spatial patterns appear in different frequency bands, their dynamic characteristics in subbands vary. In addition, delineating subbands was more helpful in distinguishing AD from NC in terms of CAP.

Time series analysis on tuberculosis cases in Kazakhstan from 2014 to 2025

Abstract Tuberculosis (TB) is a major cause of morbidity and mortality worldwide. The seasonal autoregressive integrated moving average (SARIMA) model is widely used for forecasting infectious disease incidence, including TB. However, there is a lack of comprehensive research on TB epidemiology and predictions for the future in Kazakhstan. Therefore, this study adopted a time series analysis of 72 monthly observations of reported TB cases in Kazakhstan from 2014-2019. The study used monthly health data from 2014-2019 for TB cases obtained from large-scale administrative records. The methodology involved using the Augmented Dickey-Fuller test for determining stationarity, ACF and PACF for identifying model parameters, and AIC/BIC for selecting the best SARIMA model, which was evaluated based on R2 score, MAE, and MAPE. The modeling dataset comprised monthly TB notification rates from 2014 to 2018, while the forecasting dataset comprised data from 2019. The findings suggest that the SARIMA model demonstrated some efficacy in predicting TB notification rates, although there remains scope for enhancing its precision. The time series was stationary after the first difference (ADF test: t-value of -3.25, P < 0.001) and not a white noise (P < 0.01). Based on ACF and PACF graphs, a SARIMA (0,1,0) (0,1,0)12 model was deemed to be the most appropriate forecasting model, with an R2 score of 0.43, MAE of 89.73 and MAPE of 0.08. To develop effective forecasting models for TB incidence, this study examined monthly TB cases in Kazakhstan from 2014 to 2019 and analyzed the seasonal patterns of TB occurrence. It is important to note that these results are preliminary and necessitate additional validation. Future studies will include correlation analyses between TB cases and meteorological data, using more recent data for TB cases, and evaluating various TB incidence forecasting models. Key messages • A SARIMA model developed for TB in Kazakhstan showed decreasing trend using time series analysis. • Evidence-based strategies for TB prevention & control, and importance of monitoring & forecasting TB incidence highlighted in this study.

Extraction of target structures in learners' corpora

Foreign language (FL) or second language (L2) corpora are sets of productions by non-native speakers, learners of a given language, which contemplate the errors and well-formed structures produced. These serve different research objectives, such as studies on language acquisition (LE and L2), phenomena of linguistic interference or analysis and diagnosis of LE/L2 proficiency levels. In the context of this research, the definition of the learner's proficiency level is often relevant, and this is done, typically, through the analysis of the presence or absence of errors in the learners' productions, based on mappings of typical or expected errors and well-formed structures for a given level of proficiency. However, contrary to the learner's error – which is explicitly marked in the corpus and whose typology and methodology of analysis constitutes a subtopic of investigation on its own –, the well-formed structures, and in particular the target structures (well-formed structures expected in the learners' productions of a given level of proficiency), are not easily identifiable in the corpora. The work presented here aims to fill this gap in COPLE2 – Corpus of Portuguese Foreign/Second Language through the use of expressions in CQL – Corpus Query Language. Based on pre-identified target structures and on the information made available in COPLE2, such as morphosyntactic tagging and different levels of information and annotation (learner production, teacher correction, normalized form, lemma, etc.), we propose query expressions in CQL that easily allow any user to immediately extract examples of target structures by proficiency level. The construction of the query expressions implies the definition and testing of the best strategies for each case and requires the systematization of linguistic rules and patterns of occurrence of the phenomena in question, but also the definition of ways to circumvent the limitations inherent to the corpus annotation, on the one hand, and the query language, on the other.

The Guaymas Basin – A hot spot for hydrothermal generation and anaerobic microbial degradation of hydrocarbons

Guaymas Basin is a young marginal rift basin in the Gulf of California characterized by active seafloor spreading, rapid deposition of organic-rich sediments, and steep geothermal gradients where sedimentary organic material of photosynthetic origin turns into hydrocarbons - potential microbial substrates. After introducing the sources of hydrocarbons in the subsurface, this short overview discusses the phylogenetic diversity, temperature range and occurrence patterns of novel alkane-oxidizing bacteria and archaea in the hydrothermal sediments of Guaymas Basin. Many of these alkane-degrading specialists function as syntrophic consortia, where sulfate-reducing bacteria accept electron from methane- or alkane-oxidizing archaea. As a source of metagenomes, enrichments, and cultures of these methodologically and conceptually challenging microorganisms, Guaymas Basin stands out as an indispensable field site that has consistently catalyzed new insights into the microbiology of anaerobic hydrocarbon oxidation and assimilation.

Exact and sampling methods for mining higher-order motifs in large hypergraphs

Network motifs are recurrent, small-scale patterns of interactions observed frequently in a system. They shed light on the interplay between the topology and the dynamics of complex networks across various domains. In this work, we focus on the problem of counting occurrences of small sub-hypergraph patterns in very large hypergraphs, where higher-order interactions connect arbitrary numbers of system units. We show how directly exploiting higher-order structures speeds up the counting process compared to traditional data mining techniques for exact motif discovery. Moreover, with hyperedge sampling, performance is further improved at the cost of small errors in the estimation of motif frequency. We evaluate our method on several real-world datasets describing face-to-face interactions, co-authorship and human communication. We show that our approximated algorithm allows us to extract higher-order motifs faster and on a larger scale, beyond the computational limits of an exact approach.

Clockwise rotation of SW Japan and timing of Izanagi–Pacific ridge subduction revealed by arc migration

Igneous rocks associated with the Cretaceous to Paleogene volcanic arc in SW Japan show ages that young from west to east in a direction parallel to the Median Tectonic Line suggesting corresponding translation of a heat source traditionally interpreted in terms of oblique subduction of a spreading ridge. However, recent oceanic plate reconstructions suggest ridge subduction may be younger than the main arc activity. Age compilations of 1227 points of felsic to intermediate Cretaceous and Cenozoic igneous rocks from the Japan arc show arc magmatism that can be separated into an early active period 130–60 Ma (stage 1), a subsequent period of quiescence 60–46 Ma (stage 2), which is followed by a resumption of igneous activity from 46 Ma onward (stage 3). In southwest Japan, the orientations of the magmatic arcs of stages 1 and 3 show and angular discordance of about 20°. The lack of active arc magmatism and the occurrence patterns of adakitic and high-Mg andesitic magmas indicate that ridge subduction occurred during stage 2. The arc age distribution pattern of stage 1 is explained by the slab shallowing related to a younging of the subducting slab as the ridge approaches. Furthermore, the obliquity of the arcs formed at stages 1 and 3 is explained by a 20° clockwise rotation of the inner zone of southwest Japan during the ridge-subduction phase. Oceanic plate reconstructions show counterclockwise rotation in the subduction direction after the ridge subduction phase, and coupling of the subducting oceanic plate with the upper plate would support microplate rotation in the inner zone. The new proposed tectonic reconstructions provide a framework to related Paleogene subduction of an active spreading ridge along the east Asia margin not only to the distribution of granitic bodies but also to rift-related basin formation on the eastern margin of the Eurasian continent and to rotation of crustal blocks indicated by paleomagnetic data of Cretaceous terranes.

Elucidating the Impacts of Various Atmospheric Ventilation Conditions on Local and Transboundary Ozone Pollution Patterns: A Case Study of Beijing, China

AbstractThe ventilation condition in the atmospheric boundary layer, which varies with the synoptic pattern, is a crucial factor affecting the transport and dispersion of air pollutants. In this study, taking Beijing as an example, local ozone (O3) accumulation and the transboundary O3 pollution (TOP) patterns during the warm season were explored under different boundary layer ventilation conditions by using integrated objective weather classification, non‐negative matrix factorization, and backward trajectory model. Results show that local sources are a major contributor to O3 pollution in the whole of Beijing, accounting for ∼73.36% of the O3 concentration on average. The local accumulation is mainly facilitated by poor ventilation conditions with weak wind speeds (<3 m/s) under favorable photochemical reaction conditions and abundant precursors, resulting in local O3 events. In contrast, the occurrence of synoptic patterns associated with TOP is more frequent, so the TOP contribution cannot be ignored, especially for the northern regions, where it may exceed 50%. Horizontal wind vector variations play a marked role in driving the TOP, affecting not only the location of the source region and transport pathway but also the transport distance and volume. In addition, a strong nocturnal low‐level jet (LLJ) results in horizontal transport and a temporary rise in O3 concentration, while a daytime LLJ stimulates a peak in O3 concentration over the downwind area, lagging by about 1 hr. Our findings provide new perspectives on the effects of boundary layer ventilation on the regulation of O3 pollution, as well as other air pollutants.