Natural Conditions Research Articles

Perspectives pour l’environnement et l’agriculture brésilienne

Brazil is a major producer of food, fiber, and bioenergy because the natural and technological conditions are favorable. The Michel Temer and Jair Bolsonaro governments have encouraged the deforestation and occupation of indigenous territories. They have lowered social protection and family farming policies. As a result, one third of the population is food insecure and more than 33 million people have fallen back into poverty. The current government should prioritize the fight against poverty and hunger. It will have to (a) recover social protection policy and stimulate food production in a more sustainable way through family farming and (b) revitalize institutions, environmental protection programs, and resume international agreements on climate and biodiversity.

Collective fishing with representatives of indigenous peoples of the North as a legalization of fishing for non-indigenous rural residents in the Primorsky Krai

Rural population who lives in the same natural and cultural landscape, and sometimes within the same vil-lage, are differentiated in their rights to access natural resources. People classified as indigenous population of the North, Siberia and the Far East (KMNS), unlike officially non-indigenous population, receive legal access to various biological resources. Positive discrimination of particular groups, for various reasons attributed to ‘more’ indigenous, has been causing controversy among anthropologists and sociologists for several decades, espe-cially regarding the situation of non-indigenous residents of multi-ethnic rural areas who do not have the right of access to natural resources, while living in the same environment. In Russia, this problem is specifically relevant for the coastal regions of the Far East, where fish and salmon roe have been historically the most important re-source of self-sustainment for both indigenous residents and resettlers. Using the example of one of the coastal areas of Primorsky Krai, where representatives of indigenous and non-indigenous peoples live alongside each other, we show how unequal distribution of rights to extract natural resources affects communication between them. Based on semi-structured interviews, informal conversations and observations collected during the field research, we have found that individual salmon fishing quotas are becoming a way to partially legalize informal fishing. Villagers go out fishing with their fellow villagers, and in case of the appearance of law enforcement agen-cies, fishermen from among KMNS take full responsibility for the catch and fishing gear on themselves. Regard-less of nationality, rural residents consider it unfair that non-indigenous peoples, who live in the same natural and climatic conditions, and have similar to KMNS economy, have no rights to catch salmonids. Thus, against the background of allocation of quotas for salmonid catching only to indigenous fishermen, new practices of reproduc-tion of solidarity and reciprocity are emerging in multiethnic rural communities.

Impacts of Exposure to Ultraviolet Radiation and an Agricultural Pollutant on Morphology and Behavior of Tadpoles (Limnodynastes tasmaniensis).

Amphibians are the most threatened vertebrate class globally. Multiple factors have been implicated in their global decline, and it has been hypothesized that interactions between stressors may be a major cause. Increased ultraviolet (UV) radiation, as a result of ozone depletion, has been identified as one such stressor. Exposure to UV radiation has been shown to have detrimental effects on amphibians and can exacerbate the effects of other stressors, such as chemical pollutants. Chemical pollution has likewise been recognized as a major factor contributing to amphibian declines, particularly, endocrine-disrupting chemicals. In this regard, 17β-trenbolone is a potent anabolic steroid used in the agricultural industry to increase muscle mass in cattle and has been repeatedly detected in the environment where amphibians live and breed. At high concentrations, 17β-trenbolone has been shown to impact amphibian survival and gonadal development. In the present study, we investigated the effects of environmentally realistic UV radiation and 17β-trenbolone exposure, both in isolation and in combination, on the morphology and behavior of tadpoles (Limnodynastes tasmaniensis). We found that neither stressor in isolation affected tadpoles, nor did we find any interactive effects. The results from our 17β-trenbolone treatment are consistent with recent research suggesting that, at environmentally realistic concentrations, tadpoles may be less vulnerable to this pollutant compared to other vertebrate classes. The absence of UV radiation-induced effects found in the present study could be due to species-specific variation in susceptibility, as well as the dosage utilized. We suggest that future research should incorporate long-term studies with multiple stressors to accurately identify the threats to, and subsequent consequences for, amphibians under natural conditions. Environ Toxicol Chem 2024;43:1615-1626. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

COVID-19 school closures and Chinese children's school readiness: Results from the natural experimental data.

To determine the associations between COVID-19 school closures and school readiness skills for Chinese kindergarteners. We utilized the natural experimental condition created by local COVID-19 outbreaks in 2022 (Study 1) to compare school readiness skills of children whose kindergartens were closed for 5 months (Group 1) with children whose kindergartens stayed open (Group 2). We further compared the school readiness skills of one pre-COVID-19 cohort (Cohort 2019) with one COVID-19 cohort (Cohort 2021) from a fifth kindergarten (Study 2). For Study 1, Group 1 included 445 children and Group 2 included 584 children aged 4-6 years. For Study 2, Cohort 2019 included 156 children and Cohort 2021 included 228 children aged 3-6 years. For both studies, survey data on four school readiness skills were collected from parents. Additionally, Study 1 collected parental locus of control data from parents. Controlling for covariates, Study 1 revealed that Group 1 and Group 2 did not differ in terms of language and emergent literacy or approaches to learning. However, Group 1 scored lower than Group 2 on health and well-being and arts and imagination. Study 2 revealed that Cohort 2021 scored higher than Cohort 2019 on language and emergent literacy but lower on the other three skills. The associations of COVID-19 school closures with Chinese children's school readiness skills were not uniform, with a positive relation with language and emergent literacy and negative associations with health and well-being, approaches to learning, as well as arts and imagination.

Attractive appearance, future wealth! How exposure to visual wealth on social media contributes to female self-objectification

Exposure to visual wealth on social media is a common phenomenon in daily life, but little research has been conducted to examine how this phenomenon affects individuals’ self-concept. By employing the social adaptation hypothesis of female self-objectification as a theoretical framework, the present research firstly investigated how visual wealth exposure on social media contributed to the self-objectification of women, and the downstream consequences linked to the self-objectification. To this end, three preregistered online studies were conducted. By adopting an online questionnaire survey, Study 1 found that there was a significantly positive relationship between visual wealth exposure and self-objectification, and economic inequality perception and competence perception played a chain-mediating role between them. By randomly assigning participants to the wealth-relevant image exposure condition or the natural scenery image exposure condition, Study 2 conceptually replicated the findings of Study 1. The following Study 3 further found that, participants exposed to wealth-relevant images displayed more preferences for an appearance-dominated job (working as a network entertainment-anchor) than those exposed to natural scenery images, and self-objectification mediated the effect of exposure condition on career choice. The current research provided additional empirical supports for the social adaptation hypothesis of female self-objectification, and also deepened our understanding of the relationship between social media use and the self-objectification of women.

Simultaneous Emerging Contaminant Removal and H2O2 Generation Through Electron Transfer Carrier Effect of Bi─O─Ce Bond Bridge Without External Energy Consumption.

Conventional advanced oxidation processes (AOPs) require significant external energy consumption to eliminate emerging contaminants (ECs) with stable structures. Herein, a catalyst consisting of nanocube BiCeO particles (BCO-NCs) prepared by an impregnation-hydrothermal process is reported for the first time, which is used for removing ECs without light/electricity or any other external energy input in water and simultaneous in situ generation of H2O2. A series of characterizations and experiments reveal that dual reaction centers (DRC) which are similar to the valence band/conducting band structure are formed on the surface of BCO-NCs. Under natural conditions without any external energy consumption, the BCO-NCs self-purification system can remove more than 80% of ECs within 30min, and complete removal of ECs within 30min in the presence of abundant electron acceptors, the corresponding second-order kinetic constant is increased to 3.62 times. It is found that O2 can capture electrons from ECs through the Bi─O─Ce bond bridge during the reaction process, leading to the in situ production of H2O2. This work will be a key advance in reducing energy consumption for deep wastewater treatment and generating important chemical raw materials.

A novel, green, and environmentally friendly PBS/nano-CaCO3 hybrid membrane

Biodegradable membrane materials can be degraded into small molecules under natural conditions, which can effectively alleviate the environmental pollution caused by the waste of traditional organic membrane materials. In this work, biodegradable poly (butylene succinate) (PBS)/nano-CaCO3 hybrid membranes has been prepared via non-solvent induced phase separation method by blending environmentally friendly nano-CaCO3 particles with PBS. The incorporation of nano-CaCO3 particles into the membrane leads to a notable enhancement in mechanical strength, from 1.03±0.05 MPa to 1.42±0.13 MPa, resulting in a substantial increase of approximately 37 %. Additionally, the introduction of these particles also contributes to a reduction in contact angle, from 63° to 56°. Consequently, the issue of inadequate mechanical strength and limited hydrophilicity of PBS membrane is effectively addressed. Moreover, the pure water permeance of membrane increases from 8.5 L·m−2·h−1·bar−1 to 89.3 L·m−2·h−1·bar−1, and the permeability is greatly improved. The permeance recovery rate of the membrane increases from 78 % to 95 %, and the anti-fouling performance is improved. In addition, PBS can be degraded after the service of PBS/nano-CaCO3 hybrid membrane, and CaCO3 particles are environmentally friendly. Therefore, the PBS/nano-CaCO3 hybrid membrane hybrid membrane prepared in this study is a green and environmentally friendly membrane material.

Synergistic biocementation: harnessing Comamonas and Bacillus ureolytic bacteria for enhanced sand stabilization

Biocementation, driven by ureolytic bacteria and their biochemical activities, has evolved as a powerful technology for soil stabilization, crack repair, and bioremediation. Ureolytic bacteria play a crucial role in calcium carbonate precipitation through their enzymatic activity, hydrolyzing urea to produce carbonate ions and elevate pH, thus creating favorable conditions for the precipitation of calcium carbonate. While extensive research has explored the ability of ureolytic bacteria isolated from natural environments or culture conditions, bacterial synergy is often unexplored or under-reported. In this study, we isolated bacterial strains from the local eutrophic river canal and evaluated their suitability for precipitating calcium carbonate polymorphs. We identified two distinct bacterial isolates with superior urea degradation ability (conductivity method) using partial 16 S rRNA gene sequencing. Molecular identification revealed that they belong to the Comamonas and Bacillus genera. Urea degradation analysis was performed under diverse pH (6,7 and 8) and temperature (15 °C,20 °C,25 °C and 30 °C) ranges, indicating that their ideal pH is 7 and temperature is 30 °C since 95% of the urea was degraded within 96 h. In addition, we investigated these strains individually and in combination, assessing their microbially induced carbonate precipitation (MICP) in silicate fine sand under low (14 ± 0.6 °C) and ideal temperature 30 °C conditions, aiming to optimize bio-mediated soil enhancement. Results indicated that 30 °C was the ideal temperature, and combining bacteria resulted in significant (p ≤ 0.001) superior carbonate precipitation (14–16%) and permeability (> 10− 6 m/s) in comparison to the average range of individual strains. These findings provide valuable insights into the potential of combining ureolytic bacteria for future MICP research on field applications including soil erosion mitigation, soil stabilization, ground improvement, and heavy metal remediation.

Transcriptomic Analysis of Sodium-Silicate-Induced Resistance against Rhizoctonia solani AG-3 in Potato

Stem canker and black scurf of potatoes, caused by Rhizoctonia solani, are economically important diseases. Although the field application of sodium silicate has been shown to improve potato’s resistance against R. solani, the underlying mechanism remains unclear. In this study, we examined this resistance using transcriptomic analysis. Potato stems inoculated with R. solani were treated with sodium silicate, while a control group received no sodium silicate treatment. The plants were grown under natural environmental conditions at the farm of Inner Mongolia Agricultural University. Potato stems were sampled 4, 8, and 12 days after treatment. Total RNA was extracted using the TRIzol reagent and transformed into cDNA. The cDNA was sequenced, the reads were aligned, and the expression levels of genes were quantified and compared between the treated and control groups. A total of 1491 genes were identified as differentially expressed genes (DEGs). Furthermore, these DEGs were found to be involved in hydrolase activity, plant–pathogen interactions, hormone signal transduction, and the phenylpropanoid biosynthesis pathway. To confirm the up- and down-regulation of DEGs, quantitative real-time polymerase chain reaction (qRT-PCR) was performed on randomly selected genes. The results showed that the application of sodium silicate induces a complex defense network in potato plants involving physical barriers, innate immunity, phytohormone signaling, and various phenylpropanoid compounds to combat R. solani infection. This study provides valuable insights into the molecular mechanisms underlying sodium-silicate-induced resistance and its potential for reducing stem canker and black scurf in potato crops.

Insight from expression profiles of FT orthologs in plants: conserved photoperiodic transcriptional regulatory mechanisms.

Floral transition from the vegetative to the reproductive stages is precisely regulated by both environmental and endogenous signals. Among these signals, photoperiod is one of the most important environmental factors for onset of flowering. A florigen, FLOWERING LOCUS T (FT) in Arabidopsis, has thought to be a major hub in the photoperiod-dependent flowering time regulation. Expression levels of FT likely correlates with potence of flowering. Under long days (LD), FT is mainly synthesized in leaves, and FT protein moves to shoot apical meristem (SAM) where it functions and in turns induces flowering. Recently, it has been reported that Arabidopsis grown under natural LD condition flowers earlier than that grown under laboratory LD condition, in which a red (R)/far-red (FR) ratio of light sources determines FT expression levels. Additionally, FT expression profile changes in response to combinatorial effects of FR light and photoperiod. FT orthologs exist in most of plants and functions are thought to be conserved. Although molecular mechanisms underlying photoperiodic transcriptional regulation of FT orthologs have been studied in several plants, such as rice, however, dynamics in expression profiles of FT orthologs have been less spotlighted. This review aims to revisit previously reported but overlooked expression information of FT orthologs from various plant species and classify these genes depending on the expression profiles. Plants, in general, could be classified into three groups depending on their photoperiodic flowering responses. Thus, we discuss relationship between photoperiodic responsiveness and expression of FT orthologs. Additionally, we also highlight the expression profiles of FT orthologs depending on their activities in flowering. Comparative analyses of diverse plant species will help to gain insight into molecular mechanisms for flowering in nature, and this can be utilized in the future for crop engineering to improve yield by controlling flowering time.

Velocity and Temperature Dependence of Steady‐State Friction of Natural Gouge Controlled by Competing Healing Mechanisms

AbstractThe empirical rate‐ and state‐dependent friction law is widely used to explain the frictional resistance of rocks. However, the constitutive parameters vary with temperature and sliding velocity, preventing extrapolation of laboratory results to natural conditions. Here, we explain the frictional properties of natural gouge from the San Andreas Fault, Alpine Fault, and the Nankai Trough from room temperature to ∼300°C for a wide range of slip‐rates with constant constitutive parameters by invoking the competition between two healing mechanisms with different thermodynamic properties. A transition from velocity‐strengthening to velocity‐weakening at steady‐state can be attained either by decreasing the slip‐rate or by increasing temperature. Our study provides a framework to understand the physics underlying the slip‐rate and state dependence of friction and the dependence of frictional properties on ambient physical conditions.

Study of the modern reclamation and ecological state of soils in Azerbaijan

For many years in the Republic of Azerbaijan, numerous reclamation and ecological measures aimed at attracting agricultural lands of natural cenoses to use in agrocenoses were carried out. The soils of the studied territory are quite unique in terms of their soil-forming structure and ecological conditions, and they differ from other regions of the country in terms of irrigation water content. The article reflects some important results of soil and water studies conducted over the last years. Determining the qualitative composition of groundwater and irrigation water in different seasons of the year using modern methods is relevant from an environmental and reclamation point of view. Based on remote sensing and geographic information system (GIS) technologies, our research is based on the analysis of natural and anthropogenic landscape changes and changes in natural conditions as a result of agricultural development in the 20 km buffer zone along the banks of Kura and Araz rivers. As a result of the conducted research, it was determined that the rapid growth of the population has caused the reduction of the area of agro-landscapes, the salinization of the soil, the drying of the water in the water basins, the expansion of the construction areas. This has disrupted the natural balance.

Evolutionary adaptations generally reverse phenotypic plasticity to restore ancestral phenotypes during new environment adaptation in cattle.

Phenotype plasticity and evolution adaptations are the two main ways in which allow populations to deal with environmental changes, but the potential relationship between them remains controversial. Using a reciprocal transplant approach with cattle adapted to the Tibetan Plateau and adjacent lowlands, we aim to investigate the relative contributions of evolutionary processes and phenotypic plasticity in driving both phenotypic and transcriptomic changes under natural conditions. We observed that while numerous genetic transcriptomic changes were evident during the forward adaptation to highland environments, plastic changes predominantly facilitate the transformation of transcriptomes into a preferred state when Tibetan cattle are reintroduced to lowland habitats. Genes with ancestral plasticity are generally reversed by evolutionary adaptations and show a closer expression level to the ancestral stage in evolved Tibetan cattle. A similar trend was also observed at the phenotypes level, with a majority of biochemical and hemorheology phenotypes showing a tendency to revert to their ancestral patterns, suggesting the restoration of ancestral expression levels is a widespread evolutionary trend during adaptation. The findings of our study contribute to the debate regarding the relative contributions of plasticity and genetic changes in mammal environment adaptation. Furthermore, we highlight that the restoration of ancestral phenotypes represents a general pattern in cattle new environment adaptation.

Adaptively learning visual model of surgical resection images via coarse-to-fine–grained strategy for pathological invasiveness prediction in indeterminate stage IA lung adenocarcinoma.

1563 Background: Indeterminate nodules with high risk of malignancy are suggested to receive video-assisted thoracoscopy biopsy. Frozen section assists surgeons to decide surgical strategies for stage IA lung adenocarcinoma (LUAD) intraoperatively, which is time-consuming and may misdiagnosis due to limited sampling and poor tissue quality. Methods: We prospectively enrolled stage IA LUAD patients underwent complete resection between June 2020 and September 2023 in Guangdong Provincial People's Hospital (GDPH), Affiliated Hospital of Guangdong Medical University, Meizhou People's Hospital. All the resected lung nodules were finally diagnosed as pre-invasive lesion (PIL), minimally invasive adenocarcinoma (MIA) or invasive lung adenocarcinoma (IAC) by FFPE pathological diagnosis. Images of the whole section of the lung nodules were taken by smartphones under natural lighting condition in operating theaters without shadowless surgical lights. Patients received preoperative anti-cancer therapy and with low-quality tumor section images were excluded. Images of nodules section, FS reports, FFPE diagnosis and clinical information were prospectively collected. Predictive artificial intelligence (AI) model was developed by a three-step process, which first predict the IAC and non-IAC region at coarse level, and identify fine level features through the high-risk region. The coarse and fine labels were then coordinated through risk ranking loss to reach a final predictive result. Results: We prospectively enrolled 1516 patients with 1638 indetermined lung nodules from preoperative chest CT following the inclusion and exclusion criteria, with 2438 images acquired from intraoperative nodule sections. The included patients have median age of 57 years old and 38.6% male patients. The pathological diagnosis for included lung nodules are 122 PIL nodules, 502 MIA nodules and 1014 stage IA LUAD. A multi-task artificial intelligence based on Coarse-to-Fine-Grained Strategy has been established to classify the indetermined lung nodules during the surgery. For binary classification, AI model reach an AUC of 0.86 in differentiation between IAC or non-IAC. For 3-classification level, AI model reach an AUC of 0.87 in differentiation between PIL, MIA or IAC. We further defined the IAC nodules into G1, G2 and G3 according to IASLC lung adenocarcinoma grading system. For 5-classification level, AI model reach an AUC of 0.86 in differentiation between PIL, MIA, IAC-G1, IAC-G2 and IAC-G3. Conclusions: Our AI models based on images of intraoperative surgical resection could effectively classify indetermined lung nodules, which can assist thoracic surgeons diagnose the nodules rapidly during the surging and decide the following surgical strategies. Clinical trial information: ChiCTR2300075999 .

Evaluation of the Pollination Efficiency of Apple Trees by Osmia excavata Alfken (Hymenoptera: Megachilidae).

The mason bee Osmia excavata Alfken is an apple pollinating insect widely distributed in northern China, in order to effectively utilize the mason bee and improve the pollination rate of apples, there is a need to evaluate the pollination efficiency of the bees. This study evaluated the pollination efficiency of the mason bee on apple orchards in Jinan and Yantai, Shandong Province, China. The study compared natural pollination areas and pollination areas with different release densities of O. excavata in terms of the effects of bee density, timing of pollination, and distance effects on fruit set rate, fruit shape index, fruit shape skewness, fruit soluble solids content, and fruit firmness. The optimal release density of bees was 6000 cocoons per hectare, resulting in the highest fruit setting rate of apple lateral flowers. From 07:00 to 14:00 was the best time for bee pollination. The optimal distance of hives from apple trees for pollination by O. excavata was 60m. Single fruit weight was significantly higher and fruit unsymmetrical rate, partial slope and hardness were all significantly lower at the release densities of 6000 or 12000 cocoons per hectare compared with 3000 cocoons per hectare or under natural pollination conditions. There was no significant difference in the content of soluble solids under different release densities. Thus, the radius of 60m from the hive was the effective pollination range and 6000 cocoons per hectare of mason bees could ensure the fruit quality of apple.

Total Soluble Protein Mediated Morphological Traits in Mustard Treated with Thiourea and Salicylic Acid

The total soluble protein-mediated morphological traits in mustard treated with Thiourea and Salicylic acid were investigated. In addition, it tested the hypothesis that the growth regulator salicylic acid protects the photosynthetic apparatus by up-regulating morphological traits. Under natural environmental conditions, seeds were sown in the field, and seed emergence was recorded. For three days after the 15-day stage, plants in the area were treated with thiourea and salicylic acid and allowed to grow for 90 days. Plants were harvested to assess various morphological traits. A follow-up application of SA and Thiourea plants improved plant height, leaf area, internodal length, leaf number, and accelerated plant activity. The up-regulation of morphological traits may have occurred in SA and Thiourea-mediated plants. After treatments, the level of total soluble protein was estimated in the leaves at proposed day intervals.

Photo-transformation of ofloxacin in natural aquatic conditions: Impact of indirect photolysis on the product profile and transformation mechanism

The natural phototransformation of organic pollutants in the environment depends on several water constituents, including inorganic ions, humic substances, and pH. However, the literature information concerning the influence of various water components on the amount of phototransformation and their impact on the development of various transformation products (TPs) is minimal. This study investigated the phototransformation of ofloxacin (OFL), a fluoroquinolone antibiotic, in the presence of various water components such as cations (K+, Na+, Ca2+, NH4+, Mg2+), anions (NO3−, SO42−, HCO3−, CO32−, PO43−), pH, and humic substances when exposed to natural sunlight. The study reveals that neutral pH levels (0.39374 min⁻1) enhance the phototransformation of OFL in aquatic environments. Carbonate, among anions, shows the highest rate constant (2.89966 min⁻1), significantly influencing OFL phototransformation, while all anions exhibit a notable impact. In aquatic environments, indirect phototransformation of OFL, driven by increased reactive oxygen species, expedites light-induced reactions, potentially enhancing OFL phototransformation. A clear difference was visible in the type of transformation products (TPs) formed during direct and indirect photolysis. The impact of indirect photolysis in the product profile was evaluated by examining the unique properties of TPs in direct and indirect photolysis. The primary transformation products were generated by oxidation and cleavage processes directed towards the ofloxacin piperazinyl, oxazine, and carboxyl groups. The toxicity assessment of TPs derived from OFL revealed that among the 26 identified TPs, TP3 (demethylated product), TP7 and TP8 (decarboxylated products), and TP15 (piperazine ring cleaved product) could potentially have some toxicological effects. These findings suggest that the phototransformation of OFL in the presence of various water components is necessary when assessing this antibiotic's environmental fate.

Carbon performance analysis of upgraded wastewater treatment plants in key control areas of the Ziya River Basin in China

Wastewater treatment plants (WWTPs) are one of the largest sources of greenhouse gas (GHG) emissions, and they are also one of the largest energy consumption industries in urban systems. With the progression of upgrading and standard-rising, WWTPs both directly and indirectly increase carbon emissions from the increased investments in facilities and usages in electricity as well as chemical agents. Here, we collected operational data from 15 WWTPs in the key control areas of the Ziya River Basin in North China and accounted for the changes in carbon performance at different technical upgrade methods. Results showed that the average carbon emission performance increased by 0.487 kg CO2/m3 after the upgrade. Carbon emissions from electricity consumption, chemical usage, biochemical process and sludge treatment accounted for 42%, 17%, 24%, and 17% of the total improvement in carbon emission performance, respectively. Reducing energy consumption, regulating chemical use and sludge comprehensive utilization are the key to carbon emission reduction. It further proposes that the development of wastewater treatment discharge standards should fully consider the comprehensive utilization of water quality classification. Regions with favorable natural conditions should make full use of their advantages by adopting economically feasible, low-energy-consuming technologies such as constructed wetlands, which offer carbon sequestration and landscaping benefits. This study provides guidance on the selection of technological pathways for pollution reduction and carbon mitigation in the wastewater treatment industry and on achieving sustainable water resource utilization.

Potential and Influencing Factors of Urban Spatial Development under Natural Constraints: A Case Study of the Guangdong-Hong Kong-Macao Greater Bay Area

As urbanization in China progresses, urban spatial development is transitioning from rapid expansion to more intensive and compact growth. This study examined the role of physical geography and environmental factors in shaping the urban spatial development in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA). Based on the current natural conditions, we selected evaluation indices from topography, hydrogeology, climatic conditions, and natural disasters. These indices were used to create a carrying capacity and suitability evaluation system for development land under natural constraints. Finally, the spatial development potential of the city was finalized by taking into account the current state of the built-up area of the city. Meanwhile, we employed the Optimal Parameters-based Geographical Detector and assessed the impact of 14 natural factors on the spatial development of urban built-up areas. In 2020, the GBA had 52,168.77 km2 of land suitable for construction, of which 34,241.13 km2 was highly suitable (61.29%) and 17,927.64 km2 was moderately suitable (32.09%). At the Bay Area level, 90.15% of the development potential remains untapped; at the city level, Zhaoqing City has the highest potential at 99.56%, while Macao has the lowest at 26.83%. Key factors influencing urban development include silty sand content, annual average relative humidity, and cumulative temperature above 0 °C, with varying impacts across different urban scales. At the Bay Area level, the silty sand content, annual average relative humidity, and cumulative temperature above 0 °C are the main influencing factors on the spatial development of urban built-up areas; at the city level, the main factors are annual average relative humidity and cumulative active temperature above 0 °C. This study reveals the important influence of natural environmental factors on urban spatial development, which is conducive to promoting sustainable development of land resources in GBA.

Influence of Feeding, Temperature and Photoperiod on Purple Sea Urchin (Paracentrotus lividus) Gonad Development

Understanding and controlling reproductive cycles and gonad maturation in cultivated species are crucial in aquaculture. The sea urchin Paracentrotus lividus, known for its edible gonads, requires careful maturation control for both reproduction and commercialization. This study explores the impact of temperature, photoperiod, and diet on gonad development to enhance year-round aquaculture practices. Using two independent cultivation systems, we manipulated environmental conditions to mimic different seasons. Sea urchins were exposed to natural or manipulated temperature and photoperiod conditions and fed either natural (Ulva spp.) or formulated diets. The gonadosomatic index (GI) and histological analysis were used to assess gonad development. The results revealed a clear correlation between environmental conditions, diet, and gonad maturation. Manipulated conditions accelerated maturation, with sea urchins showing advanced stages compared to natural conditions. Furthermore, sea urchins fed formulated diets exhibited higher GI values, indicating enhanced maturation. Histological analysis confirmed accelerated maturation, particularly in females. This study underscores the feasibility of controlling gonad maturation through environmental manipulation and diet, enabling year-round marketable gonad production. Providing formulated diets rich in polyunsaturated fatty acids, notably docosahexaenoic acid (DHA), enhances the commercial value of sea urchins. These findings optimize aquaculture practices for P. lividus, highlighting its adaptability to the maximal production of gonads throughout the year.