Assessment of forest fragmentation and ecological dynamics in Western Himalayan Region over three decades (1990-2020).

A spatial assessment of temporal forest cover changes is essential for effective forest conservation and management practices. This study analyzes changes in forest cover and the evolution of forest spatial configuration using Landsat satellite imagery over the past three decades (1990-2020) in Azad Jammu and Kashmir (AJK), Pakistan. To achieve the objectives, landscape metrics and forest fragmentation analyses were applied.

Tooth replacement of the filter-feeding pterosaur Forfexopterus and its implications for ecological adaptation.

A "comb-dentition", characterized by long, needle-like, and closely-spaced teeth, is found in the ctenochasmatid pterosaurs as an adaptation for filter-feeding. However, little is known about their tooth replacement pattern, hindering our understanding of the development of the filter-feeding apparatus of the clade. Here, we describe the tooth replacement of the pterosaur Forfexopterus from the Jehol Biota based on high-resolution X-ray Computed Tomography (CT) reconstruction.

The first ornithocheiromorph humerus from Wuerho (Urho), China, with a new isotopic age of the Tugulu Group.

Pterosaur remains are rare from the lowermost Cretaceous, hampering our understanding of the taxonomic and morphological diversities of pterosaurs during this period. The Lower Cretaceous Tugulu Group in Wuerho, China is renowned for hosting the Wuerho Pterosaurian Fauna (WPF), which has so far yielded numerous fossil remains of two dsungaripterid pterosaurs, Dsungaripterus weii and Noripterus complicidens. Here we report a partial ornithocheiromorph humerus from the WPF, representing a deeply divergent clade from Dsungaripteridae.

Strong precursor softening in cubic CaSiO perovskite.

CaSiO[Formula: see text] perovskite (CaPv) is the last major mineral in the Earth's lower mantle whose elasticity remains largely unresolved. Here, we investigate the elasticity of CaPv using ab initio machine-learning force fields (MLFF). At room temperature, the elasticity of tetragonal CaPv determined by MLFF molecular dynamics (MD) agrees well with experimental measurements after considering temperature induced variations in the hydrostatic structure, proving the effectiveness of the method.

Riverine microplastics in the Mount Everest region affected by glacier meltwater.

Understanding the distribution and drivers of microplastics (MPs) in remote and sensitive environments is essential for assessing their ecological impacts and devising mitigation strategies. This study investigates the distribution and characteristics of MPs in streams and sediments of the Mt. Everest region.

Identifying dehydration-induced shear velocity anomaly in the Earth's core-mantle boundary.

The steep temperature gradient near the bottom of the mantle is known to generate a negative correlation between the shear wave velocity ( ) and the depth in most regions of the D″ layer, as detected by seismological observations. However, increasing with depth is observed at the D″ layer beneath Central America, where the Farallon slab sinks, and the origin of this anomaly has not been well constrained. Here, we calculate the thermoelastic constants and obtain the elastic wave velocities of hydrous phase H with various Al contents and cation configurations, which may act as a water carrier to the D″ layer.

Re-evaluation of mastodon material from Oregon and Washington, USA, Alberta, Canada, and Hidalgo and Jalisco, Mexico.

The presence of at least two contemporaneous Pleistocene mastodon taxa in North America ( and ) invites re-examination of specimens at the geographic margins of each species in order to determine range boundaries, overlaps, and fluctuations. Third molars from Oregon in the United States, as well as from Hidalgo and Jalisco in Mexico, were found to be morphologically consistent with . Washington in the United States includes a number of specimens that could not be confidently assigned to either taxon.

A chitosan-based sensing membrane for on-site and sensitive dual-channel portable detection and efficient adsorption of Pb in groundwater.

The presence of lead ion (Pb) in groundwater poses a serious risk to human health, even at low levels. Therefore, it is essential to develop a new strategy for both selective detection and effective removal of Pb in groundwater, which has been rarely reported. Here, we developed a multi-functional chitosan-based fluorescent sensing membrane (CM-L/CG) by using a casting method for the sensitive/selective detection and removal of Pb in groundwater.

Study of Ultrasound-Assisted Low-Pressure Closed Acid Digestion Method for Trace Element Determination in Rock Samples by Inductively Coupled Plasma Mass Spectrometry.

In this paper, a method of ultrasound-assisted low-pressure closed acid digestion followed by inductively coupled plasma mass spectrometry (ICP-MS) analysis was proposed for trace element quantification in rock samples. By using 1.5 mL of a binary acid mixture of HNO-HF with a ratio of 2:1, rock powder samples of 50 mg were completely decomposed in 12 h at 140 °C after 4 h of ultrasonic treatment with or without pressure relief procedure.

Bioremediation of Heavy Metal-Contaminated Solution and Aged Refuse by Microbially Induced Calcium Carbonate Precipitation: Further Insights into .

Recently, the ability of microbial-induced calcium carbonate precipitation (MICP) to remediate heavy metals has been widely explored. was selected to remediate heavy metal-contaminated solution and aged refuse, exploring the feasibility of bioremediation of heavy metals and analyzing the changes in heavy metal forms before and after bioremediation, as well as the mechanism of remediation. The results showed that achieved remediation rates of 95%, 84%, 97%, and 98% for Cd, Pb, Zn, and Cr (III) in contaminated solution, respectively.

Rare earth elements in the Yellow River estuary, China: Composition, distribution, and pollution insights.

Rare earth elements (REE) are emerging aquatic trace pollutants. A total of 191 sediment samples were analyzed from the Yellow River estuary to study the REE geochemical behavior and environmental impact. The results showed that the samples contained high REE levels, and the average total amount of REE was 195.

Approaches for estimating the unsaturated hydraulic conductivity of compacted quartz sand via particle packing theory.

The unsaturated hydraulic conductivity (K) is one of the most important properties for evaluating moisture and gas migration in soil. However, the precise measurement of K in the laboratory often requires considerable time and economic costs. Currently, the most commonly used method to calculate K is to obtain it from the soil-water characteristic curve (SWCC) and saturated hydraulic conductivity.

Seismic versus aseismic slip for the 2023 Kahramanmaraş earthquake doublet.

Interplay between seismic and aseismic slip could shed light on the frictional properties and seismic potential of faults. The well-recorded 2023 Kahramanmaraş earthquake doublet provides an excellent opportunity to understand their partitioning on strike-slip faults. Here, we utilize InSAR and strong motion data to derive the coseismic rupture during the doublet, ~4-month postseismic afterslip, and slip distributions of two Mw>6.

Optimal magmatic oxidation conditions for giant porphyry copper deposits.

It is widely accepted that moderately to highly oxidized magmas are needed to form porphyry copper deposits (PCDs). However, only a few studies have attempted to investigate the effects of variable magmatic fO values on the formation of PCDs. Based on previously published studies, the magma oxygen fugacity of giant PCDs is mainly concentrated between ΔFMQ -0.

Seasonal productivity of the equatorial Atlantic shaped by distinct wind-driven processes.

The eastern equatorial Atlantic hosts a productive marine ecosystem that depends on upward supply of nitrate, the primary limiting nutrient in this region. The annual productivity peak, indicated by elevated surface chlorophyll levels, occurs in the Northern Hemisphere summer, roughly coinciding with strengthened easterly winds. For enhanced productivity in the equatorial Atlantic, nitrate-rich water must rise into the turbulent layer above the Equatorial Undercurrent.

Source-oriented health risk assessment of soil potentially toxic elements based on Monte Carlo simulation in the upper reaches of Wei River Basin, China.

The natural environment and public health are gravely threatened by the enrichment of soil potentially toxic elements (PTEs). To explore the contamination level, sources and human health risks posed by PTEs, high-density soil sampling was carried out in the upper Wei River region (UWRR). The results demonstrated that the pollution risk and ecological risk in UWRR as a whole were at a low level, but there were moderate or higher ecological risks of Hg and Cd in some areas.

Enhanced mercury deposition in Arctic Alaskan lake sediments coincides with early Holocene hydroclimate shift.

Substantial amounts of mercury (Hg) are projected to be released into Arctic watersheds as permafrost thaws amid warmer and wetter conditions. This may have far-reaching consequences because the highly toxic methylated form of Hg biomagnifies rapidly in ecosystems. However, understanding how climate change affects Hg dynamics in permafrost regions is limited due to the lack of long-term Arctic Hg records.

Insights on the evolution and adaptation toward high-altitude and cold environments in the snow leopard lineage.

How snow leopard gradually adapted to the extreme environments in Tibet remains unexplored due to the scanty fossil record in Tibet. Here, we recognize five valid outside-Tibet records of the snow leopard lineage. Our results suggest that the snow leopard dispersed out of the Tibetan Plateau multiple times during the Quaternary.

Bacteria-Produced Algicide for Field Control of Toxic Dinoflagellates Does Not Cause a Cortisol Stress Response in Two Estuarine Fish Species.

Application of algicides produced by naturally occurring bacteria is considered an environmentally friendly approach to control harmful algal blooms. However, few studies assess the effects of bacterial algicides on non-target species, either independently or with other stressors. Here, we measured sub-lethal effects of dinoflagellate-specific algicide IRI-160AA on the estuarine fish Fundulus heteroclitus and Menidia menidia in laboratory experiments.

State shifts in the deep Critical Zone drive landscape evolution in volcanic terrains.

Volcanic provinces are among the most active but least well understood landscapes on Earth. Here, we show that the central Cascade arc, USA, exhibits systematic spatial covariation of topography and hydrology that are linked to aging volcanic bedrock, suggesting systematic controls on landscape evolution. At the Cascade crest, a locus of Quaternary volcanism, water circulates deeply through the upper [Formula: see text]1 km of crust but transitions to shallow and dominantly horizontal flow as rocks age away from the arc front.

The capacity of human interventions to regulate PM concentration has substantially improved in China.

The rapid urbanization in China has brought about serious air pollution problems, which are likely to persist for a considerable period as the urbanization process continues. In urban areas, the spatial distribution of air pollutants represented by PM has been proved mainly affected by emission, urban landscape pattern (short as ULP), as well as meteorological conditions. However, the contributions of these factors can seriously vary with different periods of urban development.

A signal amplifying MOF-based probe:on-site and ultrasensitive dual-channel portable detection of Hg in groundwater through a fluorimetrically and RGB-based sensing assay.

Mercury (II) ions (Hg) are a significant source of heavy metal contamination in groundwater, posing a serious threat to human health and the environment. Therefore, there is an urgent need for the development of a new detection technique with high sensitivity for monitoring Hg in contaminated groundwater. Here, we developed a signal amplifying MOF-based probe (NXS@ZIF-8) for on-site and ultrasensitive dual-channel portable detection of Hg in groundwater.

Pollution characteristics and potential sources of Peroxyacetyl Nitrate in a petrochemical industrialized City, Northwest China.

Peroxyacetyl Nitrate (CHC(O)ONO, PAN), a typical secondary product of photochemical reactions, is well known to be a better photochemical indicator due to the only secondary photochemical source in the troposphere. Studies on PAN pollution are sparse in northwest China, resulting in a limited understanding of photochemical pollution in recent years. Herein, the measurement of PAN, O, volatile organic compounds (VOCs), NO, other related species, and meteorological parameters were conducted from May 1 to August 31, 2022, at an urban site in Lanzhou.

Spatiotemporal distribution of global peatland area during the Holocene.

Peatlands are a key component of terrestrial ecosystems, and their development has an important impact on global carbon cycle and climate change. However, the long-term evolution of global peatlands remains uncertain, particularly their spatial distribution. We compiled 4700 basal peatland data during Holocene, and 669 pollen data of Sphagnum with basal and end ages, to allow a more robust reconstruction of the spatial distribution of peatlands.

Temperature-Controlled Gas Hydrate Nucleation in the Heterogeneous Environment.

Nucleation of multicomponent systems is a pervasive phenomenon in nature and is pertinent to a diverse array of scientific and industrial challenges. The nucleation mechanisms of immiscible multicomponent systems remain unclear. Here, gas hydrate is employed as a model system to study the nucleation of multicomponent systems.