Low Depth Research Articles

Non-invasive colorectal cancer detection using multimodal deep learning ensemble classifier.

3066 Background: The demand for alternative, non-invasive methods for colorectal cancer (CRC) screening is substantial. Cell-free DNA (cfDNA) whole genome sequencing (WGS) offers a promising avenue, utilizing diverse fragmentomic data. We aimed to develop a new approach: integrating fragment end motif by size (FEMS) with genomic coverage (COV) of cfDNA to enhance CRC screening. Methods: Participants were comprised of 1,506 colonoscopy verified normal samples, 130 advanced adenoma (AA) patients, 302 CRC patients (stage I: 28.5%, stage II: 25.5%, stage III: 31.1%, stage IV: 14.2%, unknown: 0.7%). We generated low depth cfDNA-WGS data (a minimum 40 million reads per sample) using the Novaseq 6000 sequencer. We minimized batch bias by normalizing with the same samples for each experimental batch. The development set comprised 1,332 samples (1,023 normal, 103 AA, and 206 CRC), while the validation set consisted of 606 samples (483 normal, 27 AA, and 96 CRC). Results: Our new algorithm achieved 84.0% sensitivity (95% CI: 81%-86%) for CRC and 69.9% (95% CI: 66%-81%) for AA in the development set, with a specificity of 90.0%. These findings were consistent in the external set with 84.9% specificity (95% CI: 82%-88%) and sensitivities of 80.2% (95% CI: 72%-88%) and 63.0% (95% CI: 44%-82%) for CRC and AA, respectively. The sensitivities across stages (Stage I: 80%, Stage II: 86.8%, Stage III: 78.8%, Stage IV: 96.7%) were similarly reflected in the validation sets (Stage I: 74%, Stage II: 83%, Stage III: 79%, Stage IV: 92%). Conclusions: Our multimodal deep learning model shows promise for accurate non-invasive colon cancer and AA detection using low-coverage cfDNA WGS. Its strong performance in detecting not only CRC but also AA lesions suggests its potential for early intervention and improved patient outcomes. The use of colonoscopy-verified normal samples strengthens the study's credibility and paves the way for future clinical translation.

Cryogenic Machining Performance of M303 at High Cutting Speeds

The material M303 is commonly used in the fabrication of machinery, automotive components, locomotive axle housings, and injection moulds. It is a stainless martensitic chromium steel known for its high strength, wear resistance, and corrosion resistance. The primary purpose of this study is to investigate the machinability of M303 under cryogenic conditions, specifically focusing on high cutting speeds. By exploring the effects of cryogenic machining on M303, the study aims to provide insights into the performance and characteristics of this material under extreme cutting conditions. This study investigates the influence of cutting parameters on the machinability of M303 in a cryogenic environment using liquid nitrogen (LN2) and coated carbide cutting tools in a high-speed turning process. The study focuses on high cutting speeds and examines essential machinability factors, including cutting forces, surface finish, and tool life. The experimental design utilises a Taguchi L4 orthogonal array to systematically study feed rates (0.1-0.2 mm/rev), depth of cut (0.2-0.6 mm), and high cutting speeds (260-340 m/min). Notably, at a low cutting speed of 260 m/min, coupled with low feed rates and depth of cut, the study reveals the longest tool life of 48.57 mintues was achieved. This condition is characterized by a good surface finish and low cutting forces with Ra of 0.9 µm and cutting force of 100 N respectively. The predominant wear occurs on the flank face, primarily due to fracturing and chipping, especially under high combinations of cutting parameters. Conversely, gradual wear is observed under low combinations of cutting parameters, resulting in an extended tool life. In conclusion, the application of LN2 proves effective under conditions of low cutting parameters. The study suggests that the risk of fracturing the cutting tool increases at higher feed rates and depths of cut, especially when combined with elevated cutting speeds. This research provides valuable insights into optimizing the machining of M303 for enhanced efficiency and tool longevity.

Seismic fragility analysis of simply supported bridges considering uncertainty in scour condition

Bridges are vital infrastructures but face compounding risks from scouring and seismic events. Although recent studies have explored these individual and overlapping hazards, they often utilize deterministic approaches and focus on specific bridge types in limited geographical areas. This study addresses these gaps by introducing a probabilistic framework for assessing the seismic performance of multi-span reinforced concrete (RC) highway bridges in the presence of scour-related uncertainties. A time-dependent scour model, informed by a Bayesian approach and literature-based uncertainties, is integrated into the framework. Probabilistic Seismic Hazard Analysis (PSHA) and record selection strategies are employed to define the seismic demand probabilistically. Monte Carlo simulation (MCS) is utilized to propagate combined uncertainties during the analysis, considering different scour scenarios defined according to the discharge peak condition of the flood event at the specific location of the bridge. In the last step of the probabilistic framework, fragility analyses are conducted on individual components and the entire system by means of nonlinear dynamic models and multiple stripe analysis (MSA). An actual five-span bridge with simply supported prestressed concrete girders, located in Chile, is used as application example of the proposed approach, considering measured hydrological data and seismic hazard of the real location of the bridge. The study identifies distinct vulnerabilities across various bridge components under scour conditions. Elastomeric bearings are particularly susceptible in scenarios characterized by low scour depths (low discharge peak condition). Conversely, abutments display heightened vulnerabilities as scour depth increases (medium discharge peak condition). Piles also exhibit notable vulnerability, escalating in scenarios with great scour depth (medium discharge peak condition). Notably, piles tend to be more susceptible than columns to scour effects, especially in bents featuring shorter columns. These disparities in vulnerability are influenced by the bridge design philosophy, as well as the synergistic effects of seismic forces and varying scour depths. System fragility curves further elucidate that the likelihood of exceeding specific damage thresholds varies according to different scour scenarios, with the deeper scour depth scenario, displaying the higher vulnerabilities.

Sensitivity Analysis and GIS Tools for Groundwater Vulnerability Assessment. (Application in the Middle Chellif Plain, Algeria)

Contamination due to rapid urban development, industrialization, and agricultural sources is increasingly threatening the groundwater resources of the plioquaternary phreatic aquifer of the Middle Western Cheliff. An intrinsic vulnerability assessment was carried out based on the DRASTIC method on parameters involved in the vertical transfer of pollution from the soil surface. The vulnerability maps obtained showed a high extension of areas of medium vulnerability (54%). On the other hand, areas of low vulnerability occupied about 36%. The high and very high vulnerability was mainly related to low water depth values (8% and 2%, respectively). The results of a sensitivity analysis using the two tests—the single parameter sensitivity analysis and the map removal sensitivity analysis—show that every parameter is, without fail, required for the computation of the vulnerability index. The validation of the vulnerability map produced by the DRASTIC method confirmed the evolution of this sensitivity which decreases towards the S.W. of the plain with nitrate concentrations between 30 and 120 mg/L. Planners can use the produced risk maps as tools to make a preliminary choice of priority locations for various forms of environmental sustainability.

Methodology exploration and reproducibility evaluation of TAI and TSI for quantitative ultrasound assessment of hepatic steatosis

Background and aimNew quantitative ultrasound techniques can be used to quantify hepatic steatosis, including tissue attenuation imaging (TAI), tissue scatter -distribution imaging (TSI), and the hepatorenal index (HRI). However, the measurement norms and the effects of fasting on these measurements remain unclear. The present study performed a methodological exploration and investigated the reliability of these measurements. MethodsIn total, 103 participants were prospectively recruited for ultrasonography and magnetic resonance imaging (MRI) scans. For the TAI and TSI data, the upper (2 cm), middle (4 cm) and lower (6 cm) areas determined according to the depth of the region of interest from the liver capsule, were sampled three times. Correlation analyses were performed to compare the measurements of TAI, TSI, and HRI with the controlled attenuation parameter (CAP) or MRI-proton density fat fraction (MRI-PDFF). Intra- and inter-operator repeatability was assessed using intraclass correlation coefficients. The effects of fasting on these measurements were then compared. ResultsThe TAI and TSI measurements obtained from the upper and middle depths exhibited stronger correlations with the CAP measurements than those obtained from the lower depth. Specifically, the mean TAI had a significant positive correlation with MRI-PDFF (r = 0.753, P < 0.0001). TAI and TSI measurements exhibited excellent intra- (0.933 and 0.925, respectively) and inter- (0.896 and 0.766, respectively) examiner reliability. However, the correlation between HRI and CAP measurements was only 0.281, with no significant correlation with MRI-PDFF, and intra- and inter-examiner reproducibility of 0.458 and 0.343, respectively. Fasting did not affect these measurements. ConclusionsTAI and TSI measurements demonstrated good intra- and interobserver reliability and correlated well with CAP and MRI-PDFF measurements. However, in practice-based clinical applications, the sampling depth should be controlled within 2–4 cm of the hepatic capsule; no fasting is required before the examination.

Low-coverage sequencing and Wahlund effect severely bias estimates of inbreeding, heterozygosity and effective population size in North American wolves.

vonHoldt etal. ((2024), Molecular Ecology, 33, e17231) (vH24) used low-coverage (average ~ 7X read depth) restriction site-associated DNA sequence data to estimate individual inbreeding and heterozygosity, and recent effective population size (Ne), in Great Lakes (GL) and Northern Rocky Mountain (RM) wolves. They concluded that RM heterozygosity rapidly declined between 1991 and 2020, and that Ne declined substantially in GL and RM over the last 50 generations. Here, we evaluate the effects of low sequence coverage and sampling strategy on vH24's findings and provide general recommendations for using sequence data to evaluate inbreeding, heterozygosity and Ne. Low-coverage sequencing resulted in downwardly biased estimates of individual inbreeding and heterozygosity, and an erroneous large temporal decline in RM heterozygosity due to declining read depth through time. Additionally, vH24's sampling strategy-which combined individuals from several genetically differentiated populations and across at least eight wolf generations-is expected to have resulted in severe downward bias in estimates of recent Ne for RM. We recommend using high-coverage sequence data ( 15-20X) to estimate inbreeding and heterozygosity. Carefully filtering individuals, loci and genotypes, and using genotype imputation or likelihoods can help to minimise bias when low-coverage sequence data must be used. For estimation of contemporary Ne, the marginal benefits of using more than 103-104 loci are small, so aggressive filtering of loci with low average read depth potentially can retain most individuals without sacrificing much precision. Individuals are relatively more valuable than loci because analyses of contemporary Ne should focus on roughly single-generation samples from local breeding populations.

Metasurface optical trap array for single atoms

Metasurfaces made of subwavelength silicon nanopillars provide unparalleled capacity to manipulate light, and have emerged as one of the leading platforms for developing integrated photonic devices. In this study, we report on a compact, passive approach based on planar metasurface optics to generate large optical trap arrays. The unique configuration is achieved with a meta-hologram to convert a single incident laser beam into an array of individual beams, followed up with a metalens to form multiple laser foci for single rubidium atom trapping. We experimentally demonstrate two-dimensional arrays of 5 × 5 and 25 × 25 at the wavelength of 830 nm, validating the capability and scalability of our metasurface design. Beam waists ∼1.5 µm, spacings (about 15 µm), and low trap depth variations (8%) of relevance to quantum control for an atomic array are achieved in a robust and efficient fashion. The presented work highlights a compact, stable, and scalable trap array platform well-suitable for Rydberg-state mediated quantum gate operations, which will further facilitate advances in neutral atom quantum computing.

Chip breakage in silk microfibre production using elliptical vibration turning

To overcome the precision limitation and environmental impact of current chemical-based production methods for manufacturing silk microfibres used for targeted drug delivery, this paper presents a high-precision, scalable, eco-friendly mechanical machining approach to produce such microfibres in the form of discontinuous chips obtained through elliptical vibration turning of silk fibroin film using a diamond tool. The length and waist width of fabricated microfibres can be precisely controlled. As each vibration cycle will produce one silk microfibre, complete and deterministic chip breakage becomes an essential and challenging task in this approach due to its unique two-phase structure. Thus, the hybrid FE-SPH numerical simulations and machining experiments were conducted to gain a pioneering and in-depth exploration of the chip-breaking mechanism in this process. It was found that applying a low depth ratio (ratio of the nominal depth of cut to the tool path vertical amplitude) and a high horizontal speed ratio (the nominal cutting speed versus the critical workpiece velocity) could effectively reduce the average tool velocity angle (the angle from the deepest cut to the tool exit point along the cutting direction). A smaller angle would enhance the diamond tool's shearing action and led to the reduction of hydrostatic pressure in the cutting zone and a consequent decrease in the ductility of silk fibroin due to its unique structure dominated by beta-sheet crystallites. The above adjustments collectively facilitated chip breakage. This paper, therefore, established a governing rule for the controlled and repeatable formation of microfibres based on the average tool velocity angle for the first time and revealed that the cutting chips would undergo complete and deterministic breakages once the angle approached below 22.6°. On this basis, the high-precision and scalable manufacturing of silk microfibres with precisely controllable length and waist width was ultimately achieved.

Effects of propofol, ketamine-propofol mixture in pediatric dental patients undergoing intravenous sedation: a clinical study

This study aimed to evaluate the clinical effects, complications (peri- and postoperative), depth of sedation, recovery times, and changes in anxiety levels in paediatric dental patients receiving intravenous sedation with propofol and ketamine–propofol mixtures. This prospective clinical study included 69 healthy children (ASA 1) aged 3–7 years. The patients were assigned randomly to propofol group (n = 23), which received propofol; 1:3 ketofol group (n = 23), which received 1:3 ketofol; or 1:4 ketofol group (n = 23), which received 1:4 ketofol. The bispectral index (BIS) and Ramsay Sedation Scale (RSS) score were recorded at intervals of 5 min to measure the depth of sedation, and vital signs were evaluated. Peri- and postoperative complications and recovery times were recorded. Anxiety levels were also evaluated using the Facial Image Scale (FIS) and changes in saliva cortisol levels (SCLs) before and after the intravenous sedation procedure. The Kruskal‒Wallis test and Wilcoxon signed-rank test were used to determine pre- and posttreatment parameters. Dunn’s test for post hoc analysis was used to determine the differences among groups. Children’s pre- and posttreatment anxiety levels did not differ significantly according to FIS scores, and increases in SCLs were detected in 1:3 ketofol and 1:4 ketofol groups after dental treatment was completed. Compared with those in the other groups, the BIS values of the patients in 1:4 ketofol indicated a slightly lower depth of sedation. The recovery time of the patients in 1:3 ketofol was longer than that of patients in propofol and 1:4 ketofol. The incidence of postoperative complications (agitation, hypersalivation, nausea/vomiting, and diplopia) did not differ among the groups. Ketamine–propofol combinations provided effective sedation similar to that of propofol infusion without any serious complications during dental treatment performed under intravenous sedation. The ketofol infusion increased the anxiety level of paediatric dental patients to a greater extent than the propofol infusion.

The role of sawtooth-shaped nano riblets on nanobubble dynamics and collapse-induced erosion near solid boundary

In this research, surfaces inspired by shark skin were engineered for aluminum (Al) slabs to investigate the influences of riblets on the collapse dynamics of nanobubbles and the resultant erosion on the slab surfaces. These effects were probed through molecular dynamics simulations. Specifically, surfaces with flat profiles as well as those with small and high sawtooth-shaped nano riblets were modelled for analysis. Near the flat surface, due to the absence of riblets, the water nanohammer, with its semi-spherical shape containing water beads under approximately 30 GPa pressure and 5000 K temperature, impulse the Al slab, transferring both temperature and pressure, thereby inducing maximum erosion. Conversely, surfaces containing riblets separate some parts of water vortices, leading to a shorter collapse time of the nanobubble and the creation of a water nanohammer with a smaller volume compared to their values near a flat surface. Moreover, due to the initial impulse of the water nanohammer to the peak of the riblet, the nanohammer splits into two or three inclined shapes. Then, they diagonally impact the main part of the Al slab, resulting in erosion. The decentralization and diagonal impulse of the water nanohammer in the presence of riblets create a lower erosion volume and depth compared to these values on a flat surface. In summary, it can be inferred that riblets can serve as a passive control method for managing erosion, thereby increasing the lifetime of hulls for ships or submarines.

RNA Polymerase II hypertranscription in cancer FFPE samples.

Hypertranscription is common in human cancers and predicts poor prognosis. However detection of hypertranscription is indirect, relying on accurately quantifying mRNA levels and estimating cell numbers. Previously, we introduced FFPE-CUTAC, a genome-wide method for mapping RNA Polymerase II (RNAPII) in formalin-fixed paraffin-embedded (FFPE) sections. Here we use FFPE-CUTAC to demonstrate genome-wide hypertranscription both in transgene-driven mouse gliomas and in assorted human tumors at active regulatory elements and replication-coupled histone genes with reduced mitochondrial DNA abundance. FFPE-CUTAC identified RNAPII-bound regulatory elements shared among diverse cancers and readily categorized human tumors despite using very small samples and low sequencing depths. Remarkably, RNAPII FFPE-CUTAC identified de novo and precisely mapped HER2 amplifications punctuated by likely selective sweeps including genes encoding direct positive regulators of RNAPII itself. Our results demonstrate that FFPE-CUTAC measurements of hypertranscription and classifications of tumors using small sections provides an affordable and sensitive genome-wide strategy for personalized medicine.

An experimental investigation into the drag reduction performance of dimpled plates in a fully turbulent channel flow

Dimpled surfaces have gained increasing attention in recent years for their potential to reduce turbulent skin friction, a capability previously acknowledged for its beneficial implications on heat transfer. As a passive drag reduction method, dimpled surfaces offer significant advantages for marine applications due to their effectiveness and practical applicability. However, despite numerous studies, conflicting opinions and inconsistent drag reduction rates persist in the literature. This paper addresses these ambiguities and offers valuable insights into the effectiveness of dimpled surfaces for drag reduction in fully turbulent flows. We conducted an extensive experimental investigation involving various dimple configurations, including different depth-to-diameter ratios, diameters and orientations, utilising a specialised Fully Turbulent Flow Channel facility and a Particle Image Velocimetry system. Our findings demonstrated that circular dimple geometries, particularly those with low depth ratios, can achieve significant drag reduction of up to 27% as the Reynolds number increases. These results highlight the substantial potential of dimpled surfaces for improving energy efficiency in marine applications, where skin friction accounts for a significant portion of the total drag experienced by large vessels.

Efficiency of Virucidal Disinfectants on Wood Surfaces in Animal Husbandry.

The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests were based on German testing guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), were inoculated with enveloped or non-enveloped viruses and then treated with one of three different disinfectants. The results revealed that intact, fine-sawn timber with a low roughness depth can be effectively inactivated. Peracetic acid proved to be the most effective disinfectant across all tests. Regardless of the pathogen and the type of wood, a concentration of 0.1% of the pure substance at a temperature of 10 °C and an exposure time of one hour can be recommended. At a temperature of -10 °C, a concentration of 0.75% is recommended. The basic chemicals formic acid and glutaraldehyde demonstrated only limited effectiveness overall. The synergistic effects of various wood components on the inactivation of viruses offer potential for further investigation. Disinfectant tests should also be conclusively verified in field trials to ensure that the results from standardised laboratory tests can be transferred to real stable conditions.

Tenacity of Animal Disease Viruses on Wood Surfaces Relevant to Animal Husbandry

The aim of this study was to analyse the hygienic suitability of wood often used in animal husbandry. To this end, the inactivation of viruses (Enterovirus E as a surrogate for non-enveloped viruses and Newcastle disease virus as a surrogate for enveloped viruses) on germ carriers consisting of various types of wood was studied over an extended period to assess the biosafety of wood as an agricultural building material. The study was designed to assess the intrinsic biocidal activity of the wood itself, without the use of a disinfectant. The laboratory tests were based on German test guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), as well as stainless-steel carriers, were inoculated with enveloped and non-enveloped viruses and stored for up to four months, and the remaining infectivity of the viruses was continuously assessed. The results showed that intact, finely sawn timber with a low depth of roughness had an inactivating effect on the viruses up to 7.5 decadal logarithmic levels. For the non-enveloped virus, inactivation was fastest on Douglas fir wood, with the target reduction for effective inactivation (reduction by factor 4.0 log10) being achieved after two weeks, and for the enveloped virus on pine wood, it was already achieved from the day of drying. The hygienic effects of the wood carriers may be due to their hygroscopic properties and wood constituents. These effects offer potential for further investigation, including tests with other wood species rich in extractives.

Ultrahigh-temperature crustal anatexis and final cratonization in Eastern Hebei, North China Craton: Insights from ca. 2.46 Ga Taipingzhai enderbites

Charnockitic rocks are a suite of granulite-facies plutonic rocks that include dominantly granitic−tonalitic and partly dioritic rocks. The Na-rich endmembers of the charnockite series, including dioritic to tonalitic rocks, are also termed enderbites. Charnockitic rocks are the main component of the cratonic-type lower continental crust in Precambrian cratons worldwide. These rocks are generally considered to be products of the anatexis of the lower crust under high- to ultrahigh-temperature conditions and play a key role in stratification between upper and lower crustal layers as well as the cratonic stabilization (cratonization) of Precambrian continents, although further study is required to gather detailed information about these rocks. In this study, a group of igneous enderbites (dioritic−tonalitic charnockites) from Eastern Hebei, North China Craton, is investigated. Zircon U-Pb dating reveals that the enderbites formed at ca. 2.46 Ga, which is coeval with the regional granulite-facies metamorphic overprinting. The enderbites are primarily composed of clinopyroxene, orthopyroxene, plagioclase, and quartz, with minor amphibole, biotite, K-feldspar, and Fe-Ti oxides. The rocks are characterized by high Fe2O3T + MgO (9.80−15.9 wt%), Cr (71.0−292 ppm), and Ni (41.2−107 ppm) contents, as well as low Al2O3 (13.9−16.6 wt%) and K2O (1.07−2.43 wt%) contents, with high Na2O/K2O ratios (1.51−4.43) and low Sr/Y (24.5−49.5) ratios. Moreover, these rocks are enriched in light rare earth elements (LREEs), (La/Yb)N = 8.06−17.8, and yield weak Eu anomalies, (Eu/Eu* = 0.80−1.18), with negative Th, U, Ta, Nb, and Ti anomalies. Various mineral thermobarometers, oxybarometers, and hydrometers are used to constrain the crystallized P-T-ƒO2-H2O conditions of the enderbites. These rocks crystallized at high temperature (860−1000 °C), crystallization pressure (8.0 ± 1.0 kbar), and H2O-poor (1.5−2.4 wt%) conditions, with oxygen fugacities (ΔQFM) of 0.0−3.0, which suggests “hot” (high-temperature) and “dry” (water-poor) crystallization conditions. The enderbites also have heterogeneous in situ zircon Hf-O isotopic compositions: εHf(t) = 2.4−7.5; δ18O = 5.78‰−7.74‰. These new data, combined with trace element characteristics, suggest that the enderbites were derived from the partial melting of metabasites, and that assimilation and fractional crystallization controlled the compositional variation in the enderbites. Further thermodynamic and geochemical modeling suggests that the anatexis of Mg-Fe−rich metabasite under ultrahigh-temperature (&amp;gt;1000 °C) and H2O-poor (1.0−1.5 wt%) conditions at a low crustal depth (∼9.0 kbar) could yield a melt composition comparable to that of the observed enderbites. Postcollisional lithospheric extension and mafic magma underplating prompted the partial melting of lower crustal metabasite at ultrahigh temperatures and normal lower crustal depths, resulting in the formation of enderbites. This study demonstrates that the enderbites could be formed by ultrahigh-temperature anatexis of metabasite with amphibole dehydration melting (Pl + Amp → Opx + Cpx + melt) and offers robust evidence of the genetic links between the ultrahigh-temperature anatexis of basic rocks and the generation of enderbites. In addition, the occurrence of ca. 2.46 Ga enderbites may mark the final cratonization of the North China Craton, and the ca. 2.50−2.45 Ga tectono-thermal event was an ultrahigh-temperature metamorphic-anatexis process rather than simple regional granulite metamorphic overprinting. Therefore, the generation and emplacement of enderbites involved not only a magmatic process but also an element redistribution process in the lower crust, which has important implications for stabilization of the North China Craton at ca. 2.5 Ga.

Introducing two improved methods for approximating radiative cooling in hydrodynamical simulations of accretion discs

ABSTRACT The evolution of many astrophysical systems depends strongly on the balance between heating and cooling, in particular star formation in giant molecular clouds and the evolution of young protostellar systems. Protostellar discs are susceptible to the gravitational instability, which can play a key role in their evolution and in planet formation. The strength of the instability depends on the rate at which the system loses thermal energy. To study the evolution of these systems, we require radiative cooling approximations because full radiative transfer is generally too expensive to be coupled to hydrodynamical models. Here, we present two new approximate methods for computing radiative cooling that make use of the polytropic cooling approximation. This approach invokes the assumption that each parcel of gas is located within a spherical pseudo-cloud, which can then be used to approximate the optical depth. The first method combines the methods introduced by Stamatellos et al. and Lombardi et al. to overcome the limitations of each method at low and high optical depths, respectively. The second method, the ‘modified Lombardi’ method, is specifically tailored for self-gravitating discs. This modifies the scale height estimate from the method of Lombardi et al. using the analytical scale height for a self-gravitating disc. We show that the modified Lombardi method provides an excellent approximation for the column density in a fragmenting disc, a regime in which the existing methods fail to recover the clumps and spiral structures. We therefore recommend this improved radiative cooling method for more realistic simulations of self-gravitating discs.

The Effect of Furrow Opener and Disc Coulter Configurations on Seeding Performance under Different Residue Cover Densities

The performance of the no-till seeder is one of the most important factors that affect the success of the no-tillage. Striking the right balance between furrow opener design and residue cover is essential for optimizing seeding conditions and ensuring sustainable agricultural practices that promote both soil conservation and high-yield crop production. This study investigates the impact of residue cover on no-tillage maize seeding after wheat harvest, focusing on plant spacing, seeding depth, mean emergence time, and percent emergence. Trials with hoe-type and double-disc-type furrow openers, accompanied by plain- or ripple-disc-type coulters, were conducted in Antalya, Turkey. The results indicate that residue cover had no significant effect on mean plant spacing, but a higher residue cover increased spacing variation. The seeding depth in hoe-type furrow opener trials remained consistent, while double-disc-type furrow openers showed lower depths with 80% and 90% residue covers. The percentage of plant emergence and mean emergence time decreased as the residue cover increased in double-disc-type furrow opener trials. At 90% residue cover, PE decreased to 60%. The impact of disc coulters on hoe-type furrow openers was limited, but they increased seeding depth and MET in double-disc-type furrow openers. These findings can help optimize residue management for improved efficiency in no-till farming systems.

The complete chloroplast genome sequence of Isoetes baodongii (Isoetaceae)

Isoetes baodongii is a diploid species of Isoetaceae distributed in low altitude area, its megaspore ornamentation is similar to tetraploid species I. sinensis. We collected leaf material of I. baodongii and sequenced it for low depth whole genome sequence, then, a complete chloroplast genome of I. baodongii was assembled and annotated. This chloroplast genome has a circular structure of 145,494 bp in length with a GC content of 38.0%, comprising a large single copy (LSC) region of 91,860 bp, a pair of inverted repeat (IR) regions of 13,207 bp each, and a small single copy (SSC) region of 27,220 bp. 136 genes were annotated, including 84 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. A maximum likelihood phylogeny tree was reconstructed after the sequences alignment, the result showed that I. baodongii formed a sister clade to the one clustered by I. sinensis, I. taiwanensis and I. orientalis. Although the chloroplast genome structure of I. baodongii is extremely similar to other species distributed in China, a well-supported phylogenetic relationship was reconstructed here, these results may provide new messages for further studies on phylogeny and evolution of vascular plant on the earth.

The Northeast Water Polynya, Greenland: Climatology, Atmospheric Forcing and Ocean Response

AbstractThe Northeast Water Polynya is a significant annually recurring summertime Arctic polynya, located off the coast of Northeast Greenland. It is important for marine wildlife and affects local atmospheric and oceanic processes. In this study, over 40 years of observational and reanalysis products (ERA5 and ORAS5) are analyzed to characterize the polynya's climatology and ascertain forcing mechanisms. The Northeast Water Polynya has high spatiotemporal variability; its location, size and structure vary interannually, and the period for which it is open is changing. We show this variability is largely driven by atmospheric forcing. The polynya extent is determined by the direction of the near‐surface flow regime, and the relative locations of high and low sea‐level pressure centers over the region. The surface conditions also impact the oceanic water column, which has a strong seasonal cycle in potential temperature and salinity, the amplitude of which decreases with depth. The ocean reanalyses also show a significant warming trend at all depths and a freshening near the surface consistent with greater ice melt, but salinification at lower depths (∼200 m). As the Arctic region changes due to anthropogenic forcing, the sea‐ice edge is migrating northwards and the Northeast Water Polynya is generally opening earlier and closing later in the year. This could have significant implications for both the atmosphere and ocean in this complex and rapidly changing environment.

WRAPPING PROCESS FOR BUILDING COMPONENTS MADE OF GLASSFIBER-AND TEXTILE-REINFORCED CONCRETE

In the research project WiFaPu (wrapping process for highly fiber-reinforced concrete using the example of a pump sump) a wrapping process has been developed that combines the advantages of glassfiber-reinforced concrete and textile-reinforced concrete in terms of manufacturing processes and composite load-bearing behavior. In this process, a fine-grained concrete is sprayed with chopped-in short fibers on a carrier sheet and the textile reinforcement to produce a thin glassfiber-and textile-reinforced concrete layer with a defined thickness. This layer is continuously wrapped up onto a formwork to obtain a pump sump with an arbitrary cross-sectional thickness. The paper reports on the challenges in the development of the wrapping process and the associated coordination of the material components to produce durable members with monolithic blow-hole cross sections, acceptable surfaces and a reduced CO2 footprint. Pump sumps are produced as demonstrator components of the process. Their load-bearing capacity as well as their suitability for use are investigated in component tests. According to the experimental load tests, components with a high load-bearing capacity are produced. Filling tests show the overall high-water impermeability of the thin-walled components. This is made possible by fine-grained concrete with low water penetration depth and very small crack widths.