Arrangement Of Sites Research Articles

Tolas, fish traps and radiocarbon dating: The spatial characterization of the Manteño site of Ligüiqui in Ecuador and its contextualization within the chronological framework of other pre-Hispanic cultures

Abstract Ecuador is a key area in South America when it comes to understanding the economic, social and archaeological aspects of pre-Hispanic cultures in the northwestern region of the Andes. Among the most complex societies to have inhabited this territory is the so-called Manteño culture (AD ∼800–1530), which spanned across most of Ecuador’s central Pacific coast. Ongoing research at the site of Ligüiqui (Manta, Manabí) has enabled us to obtain a more complete overview of the chronological sequence of the Manteño period as well as contributing further data on the advanced stage of social development reached during the period; characterized by the hierarchical arrangement of sites, the use of extensive settlement models, and semi-circular stone fish traps (corrales). In order to understand the role played by this coastal site in the complex Manteño culture, a detailed radiocarbon study was performed in the sequence of the Ligüiqui site. In addition, using a detailed review of available Manteño settlement radiocarbon data (13 sites and 64 dates), we established a chronostratigraphic framework for the culture. Our data indicate that Ligüiqui probably acted as a supply centre for marine-origin products from the twelfth century onwards with activity peaking during the Late Manteño period. A multisite comparison using Bayesian modeling indicates an early onset of the Manteño culture in Ligüiqui around AD 700, and a general demise in most of the sites AD ∼1500 or slightly before. This culture finally collapsed before AD ∼1600 during the early Spanish colonial period. Only one site, La Libertad, shows potential evidence of having remained a Manteño settlement after that date.

A Two-Dimensional Metal-Organic framework for efficient recovery of heavy and light rare earth elements from electronic wastes

Recycling and recovery of rare earth elements (REEs) from electronic wastes can accelerate efforts to mitigate the environmental burden associated with their excessive mining, while catering for their growing demand. Contemporary recovery strategies are yet to make an impact at an industrial scale due to low REE uptakes, complex mechanisms, and high regeneration energies, leading to an overall poor scalability. Here, we report a two-dimensional metal–organic framework (BNMG-1) featuring a dense arrangement of active adsorption sites for the high uptake of heavy and light REEs. BNMG-1 with a lateral dimension of ca. 350 nm and a thickness of 14 nm was synthesized via a facile one-pot reaction using a green solvent under room temperature and atmospheric pressure. The two-dimensional structure of BNMG-1 was resolved using three-dimensional electron diffraction and EXAFS analysis. Batch experiments showed BNMG-1 to have an adsorption capacity of 355.8 mg/g for Nd3+, 323.1 mg/g for Y3+, 331 mg/g for Dy3+, 329mg/g for Tb3+ and 333 mg/g for Eu3+, which is a near-benchmark performance for a non-functionalised MOF. The adsorption efficiency for Nd3+ reached 99 % by 6 h and 88 % by 48 h for Y3+. The adsorption efficiency did not get affected over a pH range of 3 to 6 and retained > 99 % of its adsorption capacity for up to 4 cycles. For application on real-life samples, CFL lamp waste and waste magnets were used as a reservoir of heavy (Yttrium) and light (Neodymium) REEs. BNMG-1 demonstrates an efficient recovery of 57 % for Neodymium from scrap magnets and 27 % for Yttrium from waste fluorescent lamps. This performance, which is maintained under acidic conditions and over multiple cycles, highlights the competitiveness of BNMG-1 for the economic large-scale recovery of REEs.

Construction of carbazole-conjugated dual-emission fluorescent covalent organic framework for distinguishing p-nitroaniline/p-nitrophenol and adsorbing nitroanilines/nitrophenols

Nitroanilines (NAs) and nitrophenols (NPs), crucial industrial raw materials, are extensively utilized across various sectors. However, the environmental pollution and health hazards stemming from their usage are significant, necessitating urgent monitoring and removal to address environmental and safety concerns. The challenge is further compounded by the presence of NAs/NPs isomers, making the selective analysis of specific isomers crucial. In response, a new post-modified fluorescent covalent organic framework (COF) termed COF@CB, exhibiting dual-emission fluorescence, was synthesized. This synthesis involved coupling a high-crystallinity fluorescent COF (COF-TTDB) with carbazole-9-ethanol (CB) via a “Williamson” reaction. COF@CB featured exceptional dual-emission fluorescence, a high specific surface area (919.4 m2·g−1), superior thermal stability, and abundant active sites. These attributes enabled COF@CB to function as a ratiometric fluorescence sensor capable of simultaneous detection and adsorption. The distinct number and arrangement of hydrogen bond sites in NAs/NPs isomers influenced the intramolecular charge transfer (ICT) effects on COF@CB, thereby enabling the COF@CB-ratiometric fluorescence sensor to distinguish and selectively detect p-NA/p-NP from isomers. Analysis of actual water samples further underscored the sensor's effectiveness in detecting p-NA/p-NP. Furthermore, the presence of multiple active sites on the COF@CB-ratiometric fluorescence sensor facilitated the adsorption of NAs/NPs, promoting the removal of them from actual samples.

End Group Effects on Anion Binding in Tetraglycine Peptide: A Computational Study.

The importance of anions in various processes has led to a search for molecules that can effectively recognize and interact with these anions. This study explores how the tetraglycine [(Gly)4] peptide in its zwitterionic, neutral, and terminally capped forms acts as a receptor for H2PO4 - and HSO4 - anions within the framework of supramolecular host-guest chemistry. Using molecular dynamics (MD) simulations, we obtained the conformations of the receptor-anion complexes. Density functional theory (DFT), quantifies the complexes' interaction energies in both gas and solvent phases. Proton transfer within the zwitterionic complex with H2PO4 - anion alters peptide charge distribution, affecting its conformation and binding site arrangement, as analysed by quantum mechanics/molecular mechanics (QM/MM) methods. Symmetry-adapted perturbation theory (SAPT) and noncovalent interactions analysis highlight the role of electrostatic interactions in these receptor-anion complexes. It emphasizes the key interactions such as N-H⋅⋅⋅⋅O and O-H⋅⋅⋅O=C between the peptide backbone and anions and elucidates the molecular recognition mechanism driven by crucial noncovalent interactions. The termination of the peptide's end groups modulates anion binding sites from the backbone to the charged N-terminal, resulting in distinct binding sites. Our findings provide insights for designing peptides tailored to function as anion receptors in diverse supramolecular chemistry applications.

The new fate of MCLR revealed by dialysis equilibrium and theoretical calculations: Influence from DOM and Fe(II)/Mn(II)

Microcystin-LR (MCLR) is a highly toxic pollutant widely distributed in eutrophic waters. The interplay between dissolved organic matter (DOM) and metal ions has been extensively reported; however, the impact of DOM-metal complexes on MCLR remains to be thoroughly studied. In this research, equilibrium dialysis was employed to study the kinetics and isotherms of MCLR adsorption by DOM, meanwhile the Density functional theory (DFT) calculations provided insights into the theoretical mechanisms of Fe(II)/Mn(II) involvement in the adsorption process. The adsorption kinetics revealed that the process is physicochemical, with chemisorption being the critical factor controlling the adsorption rate. The adsorption isotherms confirmed that Fe(II) alters the spatial arrangement of adsorption sites on the superficies of DOM, with the complexes of Fe(II) and DOM from the macrophyte-dominated regions of Lake Taihu (MDR-Fe(II)) showing the uppermost adsorption capacity of 6193.965 µg/g among all combinations. The influence of different cations (K+, Ca2+, Na+, Mg2+) on the adsorption of MCLR to DOM is divergent, with metals either reducing MCLR adsorption through competition for adsorption sites or increasing it by forming ternary complexes. The pH decrease reduced the affinity of DOM to metal ions while simultaneously enhancing MCLR adsorption through changes in its ionization state. DFT calculations demonstrated that Fe(II)/Mn(II) reduces the resistance to interaction between functional groups on DOM and MCLR, with carboxyl-Fe(II)-carboxyl interactions showing the highest binding energy (ΔG = −7.253 eV). Overall, Fe(II)/Mn(II) enhances the adsorption of MCLR via altering the structure and surface electrostatic potential distribution of DOM. This research indicates that the ultimate fate of MCLR in aquatic ecosystems is affected by DOM and metal ions.

Church surroundings as spaces with a health-promoting function – possibilities and dilemmas

Motives: Climate and socio-economic changes exert a negative influence on human health, both physical and psychological. Therefore, various solutions are needed to address this problem, and the spaces surrounding religious sites should be analysed to determine whether they can improve health. Can plant and garden arrangements accompanying parish churches have health-promoting properties?Aim: The aim of this work was to answer the above questions by analysing selected parish churches of the Lublin Archdiocese.Results: An analysis of the compositional structure of vegetation and the functional-spatial arrangement of religious sites revealed that these spaces have vast, albeit not fully utilised potential. Despite the fact that these spaces are addressed predominantly to believers, their unique features can promote recreation and even improve health, regardless of one’s religious beliefs and practices.

A Specific Review of CO2 Catalytic Conversion Reactions Based on the Concept of Catalytic Sites Contiguity

AbstractThermocatalytic conversions of carbon dioxide (CO2) to value‐added products offer promising approaches to achieving net negative emissions. The catalysts for CO2 conversions, particularly for CO2 hydrogenation reactions, usually involve more than one catalytic sites working together. In this review, we first introduce the advanced characterization techniques used to identify the catalytic sites in CO2 hydrogenation catalysts, sites for hydrogen (H2) activation and CO2 adsorption/activation. We then discuss how the dual or multiple‐site configurations influence the catalytic activity and selectivity in reactions such as reverse water‐gas shift (RWGS), CO2 methanation, and CO2 hydrogenation for methanol (MeOH). We finally explain the Catalytic Sites Contiguity (CSC) concept that our research group developed from the work in CO2 reforming of methane and use it to understand the relationship between the spatial arrangement of catalytic sites and the efficiency of reactant activation and conversion in recent publications on MeOH synthesis from CO2 hydrogenation. We hope our insights into the impact of CSC on catalytic performance lead to a potential top‐down design method in optimizing the CO2 hydrogenation catalysts.

Targeted mutagenesis of specific genomic DNA sequences in animals for the in vivo generation of variant libraries.

Understanding how the number, placement and affinity of transcription factor binding sites dictates gene regulatory programs remains a major unsolved challenge in biology, particularly in the context of multicellular organisms. To uncover these rules, it is first necessary to find the binding sites within a regulatory region with high precision, and then to systematically modulate this binding site arrangement while simultaneously measuring the effect of this modulation on output gene expression. Massively parallel reporter assays (MPRAs), where the gene expression stemming from 10,000s of in vitro-generated regulatory sequences is measured, have made this feat possible in high-throughput in single cells in culture. However, because of lack of technologies to incorporate DNA libraries, MPRAs are limited in whole organisms. To enable MPRAs in multicellular organisms, we generated tools to create a high degree of mutagenesis in specific genomic loci in vivo using base editing. Targeting GFP integrated in genome of Drosophila cell culture and whole animals as a case study, we show that the base editor AID evoCDA1 stemming from sea lamprey fused to nCas9 is highly mutagenic. Surprisingly, longer gRNAs increase mutation efficiency and expand the mutating window, which can allow the introduction of mutations in previously untargetable sequences. Finally, we demonstrate arrays of >20 gRNAs that can efficiently introduce mutations along a 200bp sequence, making it a promising tool to test enhancer function in vivo in a high throughput manner.

Interactions that define the arrangement of sugar-binding sites in BDCA-2 and dectin-2 dimers.

The sugar-binding receptors dectin-2 and blood dendritic cell antigen 2 (BDCA-2) bind oligosaccharide ligands through extracellular carbohydrate-recognition domains (CRDs) and initiate intracellular signaling through Fc receptor γ adapters (FcRγ). Dectin-2 stimulates macrophages in response to pathogen binding while BDCA-2 modulates cytokine production in plasmacytoid dendritic cells. The oligomeric states of these receptors and the orientations of their CRDs have been investigated by analysis of a naturally occurring disulfide-bonded variant of BDCA-2 and by replacement of transmembrane domains with N-terminal dimerization domains to create extracellular domain dimers of both dectin-2 and BDCA-2. Analysis of these constructs, as well as previously described crystal structures of the CRDs from these proteins and a novel structure of an extended version of the extracellular domain of dectin-2, showed that there is only limited interaction of the CRDs in the dimers, but interactions can be stabilized by the presence of the neck region. The resulting orientation of sugar-binding sites in the dimers would favor crosslinking of multiple dimers by oligosaccharide ligands, causing clustering of FcRγ to initiate signaling.

Precise fine-tuning of the defect degree in FeNi-TDC nanoarrays via fluorinated acetic acid for rapid urea-assisted hydrogen production in seawater

Precisely regulating the defect degree in metal-organic framework (MOF) crystals and exploring the structure-activity relationship is of great significance for urea-assisted seawater electrolysis to produce green hydrogen. Herein, a series of X-FeNi-TDC nanoarrays with various defects are successfully constructed through the competitive coordination of ligand 2,5-thiophenedicarboxylic acid (H2TDC) and fluorinated acetic acid modulators with different pKa and coordination ability of -COO. The 20D-FeNi-TDC nanosheets containing more unsaturated sites and moderate electron delocalization exhibit multifunctional activity with an overpotential of 194 mV in OER, 116 mV in HER and an applied voltage of 1.326 V in UOR at 10 mA cm-2. In addition, small angle X-ray scattering (SAXS), small angle neutron scattering (SANS), X-ray absorption near-edge structure (XANES) and density functional theory (DFT) calculation further elucidate alterations in pore structure and electronic arrangement of metal sites. This study provides insight into the mechanism by which modulators regulate defects in MOF-based electrocatalyst.

Active site requirements for bio-alcohol dehydration: Effect of chemical structure and site proximity

Synthesis-structure-activity relations are reported, describing how interzeolite conversion (IZC) allows synthesis of ZSM-5 (MFI framework) with fixed physicochemical properties, except the variable local acid site (Al) arrangement, by variation of the synthesis time. Local confinement and acidity effects are probed by applying both H-ZSM-5 and Na-ZSM-5 samples in alcohol dehydration. Pyridine and divalent cobalt ion probing are used to quantify the amount of accessible acid sites and of Al in close proximity. Al in close proximity shows a strong influence on n-butanol dehydration turnover rates. The turnover rates are also strongly dependent on local confinement: in Na-form, ZSM-5 synthesized with more Al present as isolated species is a factor of 3–7 times more active than Na-ZSM-5 with fewer isolated Al. However if the zeolites are in proton form, ZSM-5 with more proximate sites show a higher activity compared to ZSM-5 with more isolated sites. Linear butene selectivity increases in Na-ZSM-5 compared to H-ZSM-5, caused by a suppressed dibutyl ether formation. The selectivity towards 1-butene is enhanced to a greater extent on proximate sites, likely due to a local/steric constraint at the active site. Decomposition of DBE over Na-ZSM-5 is more active compared to n-butanol dehydration, independent of acid site proximity. Also for 2-propanol dehydration, Na-ZSM-5 is less active than H-ZSM-5, yet the activity difference is attenuated compared to n-butanol dehydration. Essentially, due to the intrinsic higher reactivity of 2-propanol, the acid site requirement is less stringent. These findings highlight the importance of local confinement and Al proximity in acid-catalyzed conversion of oxygenated compounds.

Iterative design of polymer fabric cathode for metal-ion batteries

Organic electrode materials (OEMs) have attracted significant attention for use in aqueous zinc-ion batteries (AZIBs) because of their abundant resources and flexible designability. However, the development of high-performance OEMs is strongly hindered by their high solubility, poor conductivity, sluggish ion diffusion kinetics, and difficult coordination toward Zn2+. Herein, inspired by fabric crafts, we have designed a robust polymer fabric through the iterative evolution of the building blocks from point to line and plane. The evolution from point to line could not only improve the structural stability and electrical conductivity but also adjust the active site arrangement to enable the storage of Zn2+. In addition to further boosting the aforementioned properties, the evolution from line to plane could also facilitate the construction of noninterference channels for ion migration. Accordingly, the poly(1,4,5,8-naphthalenetetracarboxylic dianhydride/2,3,5,6-tetraaminocyclohexa-2,5-diene-1,4-dione) (PNT) polymer fabric has the most enhanced structural stability, optimized active site arrangement, improved electrical conductivity, and suitable ion channels, resulting in a record-high capacity retention of 96% at a high mass loading of 56.9mg cm−2 and a stable cycle life of more than 20,000 cycles at 150C (1C=200 mA g−1) in AZIBs. In addition, PNT exhibits universality for a wide range of ions in organic electrolyte systems, such as Li/Na/K-ion batteries. Our iterative design of polymer fabric cathode has laid the foundation for the development of advanced OEMs to promote the performance of metal-ion batteries.

Insights into the Synaptic Properties of Dopamine Release Revealed by Single Walled Carbon Nanotube Biosensors

It is thought that there are two distinct modes of chemical neurotransmission, referred to as fast (synaptic) transmission and slow (volume) transmission. Fast transmission, mediated by ligand-gated ionotropic receptors, operate with millisecond temporal and nanometer spatial precision in excitatory and inhibitory synapses, primarily mediated by glutamate and GABA, respectively. In contrast, slow transmission relies on activation of G-protein coupled receptors (GPCRs) and is mediated by several classes of neuromodulators, including dopamine. Neuromodulators are thought to operate at temporal scales that range from hundreds of milliseconds to minutes, with a spatial specificity that is insufficiently understood but generally described as “diffuse”. In this work, we provide new evidence that shows the spatial precision of dopamine transmission is highly reminiscent of the spatial properties of signaling mediated by the fast acting neurotransmitters.To gain this insight, we used an optical assay named “DopaFilm” that is based on oligonucleotide functionalized single walled carbon nanotube dopamine sensors (nanosensors). Primary dopaminergic neurons were grown on top of glass coverslips functionalized with nanosensors, which enabled visualization of dopamine exocytosis events in single release sites under a continuous 785nm excitation laser. In axonal arbors, DopaFilm can report evoked and spontaneous dopamine release events with high signal to noise ratios of up to 50. Recording on DopaFilm revealed dopamine release is fast, calcium-dependent, and reliant on similar presynaptic protein machinery employed by fast neurotransmitters. These findings challenge the notion that dopamine is a slow transmitter; however it doesn’t preclude the possibility of imprecise spatial signaling, consistent with volume transmission theory. More recent data from our lab now challenges the spatial characteristics of volume transmission model as currently understood in the literature. In this talk, I will discuss new insights gained on dopamine signaling including clear examples of precise spatial arrangements of dopamine release sites, and ultrastructural, biochemical and spatial transcriptomic data that shows that neuromodulatory action can be highly spatially precise in nature.

Nanoconfined Silver Nanoclusters Combined with X-Shaped DNA Recognizer-Triggered Cascade Amplification for Electrochemiluminescence Detection of APE1.

Apurinic/apyrimidinic endonuclease 1 (APE1), as a vital base excision repair enzyme, is essential for maintaining genomic integrity and stability, and its abnormal expression is closely associated with malignant tumors. Herein, we constructed an electrochemiluminescence (ECL) biosensor for detecting APE1 activity by combining nanoconfined ECL silver nanoclusters (Ag NCs) with X-shaped DNA recognizer-triggered cascade amplification. Specifically, the Ag NCs were prepared and confined in the glutaraldehyde-cross-linked chitosan hydrogel network using the one-pot method, resulting in a strong ECL response and exceptional stability in comparison with discrete Ag NCs. Furthermore, the self-assembled X-shaped DNA recognizers were designed for APE1 detection, which not only improved reaction kinetics due to the ordered arrangement of recognition sites but also achieved high sensitivity by utilizing the recognizer-triggered cascade amplification of strand displacement amplification (SDA) and DNAzyme catalysis. As expected, this biosensor achieved sensitive ECL detection of APE1 in the range of 1.0 × 10-3 U·μL-1 to 1.0 × 10-10 U·μL-1 with the detection limit of 2.21 × 10-11 U·μL-1, rendering it a desirable approach for biomarker detection.

Re-design of homestay in Takengon city with contemporary Gayo concept

Abstract As tourism develops in the city of Takengon, it is considered profitable for lodging business owners, from star-rated accommodation to jasmine classes emerging in the city of Takengon, making competition very tight. One type of accommodation business that is currently competitive and has great potential to grow rapidly is homestay. With the existing land, the arrangement of the homestay building is still not optimal, where the activities and circulation of the owner still mingle with guests. Likewise, the standard of accommodation facilities still needs to be added to maximize services. Generally, homestays are located in residential areas or tourist villages because of their function as a medium of introduction to the surrounding culture. Homestay re-design aims to redesign the homestay building according to its function with a picture of the life of the gayo people living in it, it can also strengthen the quality of homestay in the future as a competitor in the lodging business competition. The contemporary architectural style was chosen due to its characteristics of being contemporary, flexible and related to the principles of gayo architecture. The research method was carried out with literature studies and field surveys. The field survey included observations, interviews and direct observations of the residents of the houses in the housing estate. Then designed new facilities for the homestay such as, special sleeping room, fire kitchen, restaurant, front office, service area, as well as site arrangement in the form of cotage and open space/ebalen. The design is carried out with the concept of applying the rules of gayo contemporary architecture, namely the application of the concept of natural harmony to the zoning of the site and the application of the concept of filigree in the figure of the building appearance.

Coordination environment modulation to optimize d-orbit arrangement of Mn-based MOF electrocatalyst for lithium-oxygen battery

Nowadays lithium-oxygen (Li-O2) batteries with metal-organic frameworks (MOFs) based oxygen electrodes have suffered from the sluggish kinetics and irreversible behavior of Li2O2 formation/decomposition, which originates from weak orbit coupling with oxygen species caused by narrow orbit arrangement of metal sites in MOFs. Modulation of coordination environment of metal sites has been regarded as the vital strategy to tune 3d orbit arrangement and electron distribution of metal sites, which is favorable for altering electron transfer pathway and oxygen electrode reaction kinetics. Herein, electron-rich ferrocene acid (FcA), as grafted ligand, is introduced on Mn sites of Mn-MOF-74 (named as Mn-MOF-74-FcA) for facilitating the oxygen electrode reactions in Li-O2 batteries. In details, due to the strong electron delocalization on electron-rich FcA ligand, the resulted metal-ligand interaction between FcA and Mn sites distorts [MnOx] coordination sphere, which induces 3d orbits rearrangement of Mn sites from (dx2-y2/dxy, dz2, dxz/dyz) to (dx2-y2, dz2, dxz, dyz, dxy) and electron transfer from electron-rich FcA to Mn sites. And the strong orbit overlapping between LiO2 intermediate and widened Mn d-band ensures the electron exchange with each other and thus reduces the energy barrier of oxygen electrode reactions. Moreover, electron transfer from FcA ligand to Mn sites also leads to the decreased energy gap between valence band (VB) and conduction band (CB). As expected, Li-O2 battery with Mn-MOF-74-FcA exhibits low overpotential of 0.82 V and long lifespan of 276 cycles at the current density of 200 mA g−1.

Laparoscopic Sleeve Gastrectomy Smart Trocar Site Modification in Patients with Extreme Obesity.

Laparoscopic sleeve gastrectomy (LSG) is one of the most common bariatric surgeries performed worldwide. Although it has established itself as a satisfactory procedure on its own, it can also function as the first part of a two-stage treatment strategy. This is especially true in situations of extreme obesity (obesity grade IV or higher). One rationale for choosing a two-stage treatment is the technical difficulty of doing other types of bariatric procedures involving anastomoses due to body physique and level of visceral adiposity. LSG in patients with such a high body mass index (BMI) is comparatively simpler technically, but it does also have a degree of complexity for similar reasons. Here, we present an innovative port configuration for LSG that can significantly reduce ergonomic challenges and enhance the safety of the procedure in patients with extreme obesity. This new trocar site arrangement is generally suitable for individuals with grade IV obesity or above. It is especially effective for people with obesity at or above grade V. Only standard laparoscopic instruments are used. This design preserves the ideal manipulation and elevation angles at 60° and allows surgeons to use standard laparoscopic instruments with lowered shoulders, reducing muscular strain and fatigue. Additionally, it improves patient safety. In patients with extreme obesity, this proposed port configuration for LSG can significantly reduce ergonomic difficulties and increase surgical safety.

Experimental study on preheating and salt circulation performance of a single receiver tube based on induction heating

The design of a light source for a molten salt receiver experimental system has become challenging owing to the complex heating characteristics of the half-circumference surface during operation. Electromagnetic induction heating is an innovative technology that can replicate a half-circle heating scenario. However, its feasibility must be verified. In this study, we constructed a single receiver tube experimental system using induction heaters and developed a 3D numerical model coupling electromagnetic field to analyze the tube temperature distribution and molten salt temperature rise during preheating and salt circulation, considering various parameters. The results indicated that the numerical simulation agreed well with the experimental results, and the induction heater successfully reproduced the half circumference heating scenario. During preheating, a lower heat flux and higher wind speed result in a more uniform temperature distribution along the circumference of the tube wall, facilitating comprehensive preheating. During salt circulation, the heat flux and inlet salt mass flow significantly affected the temperature of the tube wall but had a relatively small effect on the back-side wall. Wind speed had the opposite effect, which was related to the arrangement of the experimental site. A higher heat flux, lower wind speed, and higher inlet salt mass flow led to a higher temperature increase in the molten salt.

Survival of red knots in the northern Gulf of Mexico

Highly migratory shorebirds are among the fastest declining avian guilds, so determining causes of mortality is critically important for their conservation. Most of these species depend on a specific geographic arrangement of suitable sites that reliably provide resources needed to fuel physiologically demanding life histories. Long-term mark-resight projects allow researchers to investigate specific potential sources of variation in demographic rates between populations. Red Knots (Calidris canutus) occur in three relatively distinct regions across the northern Gulf of Mexico, and two of these areas have been experiencing episodic harmful algal blooms (red tide) with increased frequency in recent decades. Since knots are mostly molluscivorous during the nonbreeding season in the Gulf, they are potentially exposed to red tide toxins at high concentrations via their filter-feeding prey. We used long-term mark-resight data from Texas, Louisiana, and Florida (USA) to estimate apparent survival, and to assess the effects of red tides on survival of Red Knots. We also assessed effects of tracking devices deployed in conjunction with the projects over the years. While overall apparent annual survival rates were similar across the three locations (0.768 – 0.819), several red tide events were associated with catastrophically low seasonal (fall) survival in Florida (as low as 0.492) and Texas (as low as 0.510). Leg-mounted geolocators, but not temporary glued-on VHF tags, were associated with a reduction in apparent survival (~8%/year). Movement of knots between the three areas was rare and site fidelity is known to be high. Harmful algal blooms are predicted to increase in frequency and severity with climate change and increased anthropogenic degradation of coastal habitats, which may further endanger these as well as other shorebird populations around the world.

The influence of fragmented landscapes on speciation.

In the face of unprecedented global transformations, unravelling the intricate mechanisms governing biodiversity patterns is imperative for predicting and interpreting species responses. An important element in this interplay is fragmentation and the spatial mosaic or arrangement of suitable sites within the landscape. Beyond its well-documented impact on biodiversity loss, fragmented landscapes also influence the origin of biodiversity, by influencing speciation dynamics. This research employs a model that integrates spatial configuration and dispersal abilities of individuals to investigate the impact of landscape configuration on species' evolutionary trajectories. Specifically, we propose a microevolutionary model where individuals are characterized by their dispersal ability and a genome, allowing population evolution and diversification. Space is explicitly characterized by suitable and unsuitable sites that define fragmented landscapes. Our model demonstrates how intermediate dispersal abilities enhance diversification. However, simulations of more fragmented landscapes result in a lower total number of individuals and a lower percentage of occupied sites by individuals, particularly when species have limited dispersal abilities. Furthermore, we have found that intermediate levels of fragmentation can stimulate greater species richness, while higher levels of speciation and extinction events tend to occur under higher fragmentations. Our results also show a non-monotonic dependence of richness on dispersal, supporting the intermediate dispersal hypothesis as a promotor of diversification, demonstrating the synergistic effects of landscape configuration and species dispersal ability in the processes of speciation, extinction, and diversification. This impact of fragmentation poses a real challenge for biodiversity in the context of a dynamic world.