Migration Distance Research Articles

Differential changes in the morphology and fuel loads of obligatory and partial migrant passerines over half a century in Britain

Migratory distances and stopover locations are changing for many passerines in response to climate change. Morphological changes have been linked to rising global temperatures in both migrants and residents, but the implications of these changes on fuel loads, and associated flight ranges are little studied. Wing length and body mass changes between 1964 and 2020 were calculated for 15 migrant and partially migrant passerines in Britain. Changes in fuel load and lean body mass were also estimated and used to predict flight ranges. Twelve of the species have undergone morphological changes and eight species, estimated fuel load changes. Nine species were estimated to have reduced flight ranges, indicating that the morphological changes have not compensated fully for the reduction in flight range experienced since 1964. Partial migrants showed greater decreases in flight ranges than did full migrants, which may indicate greater behavioural plasticity in the former. Those species which do not adapt morphologically or behaviourally may be unable to complete long migrations, resulting in restriction to sub-optimal breeding/wintering habitats, or a need for a sooner first stop and more stops en route. This highlights the importance of conserving migratory stopover sites, particularly in the Mediterranean and North Africa that immediately precede major geographical barriers, as-well-as breeding and wintering grounds.

Geomorphology and sediment mobility on sand banks: A study of Dogfish Bank, Hecate Strait, Northeast Pacific Ocean

AbstractMovement of sediment along shallow continental shelves is a natural process with wide‐ranging environmental and economic implications, making it of high importance to marine spatial planning efforts in the offshore. Development of marine renewable energy, for instance, requires detailed understanding of the morphodynamics of mobile bedforms to select foundation types and ensure safe installation of infrastructure in shallow shelf environments. This study evaluates geomorphology and sediment mobility of Dogfish Bank (< 20 mbsl) in the Hecate Strait offshore British Columbia, Canada, using hydroacoustic and airborne bathymetric data combined with seismic profiles and grain‐size information. These data reveal current‐swept features ranging from sediment‐depleted lag to sediment‐abundant sand ridges and dunes, with sand ribbons and furrows in‐between. Seismic reflection data show up to 15 m of surficial sand concentrated beneath north‐aligned sand ridges that dominate the bathymetry of northwest Hecate Strait. Sand ribbons (typically understood sediment‐limited features in shallow marine environments) are notably maintained over seabed with comparable sand thickness to adjacent dunes (i.e. sediment‐abundant features), suggesting local spatial variability in hydrodynamics and sediment characteristics (principally grain size) influence expression of mobile bedforms. Repeat mapping between 2008 and 2019 shows dunes and ribbons both migrate northwards, with largest seafloor changes along northeast‐facing lee sides of dunes, matching closely with published models of sediment mobility which suggest northward bedform migration is largely driven by storms. Median total migration distance is 164 m (northward) for dunes (time‐averaged rate of 14.9 m/year). Sand ribbons show less migration (median northward distance of 73 m) and migrate in a depth‐dependent manner. Because sand ribbons are typically flow‐parallel features, their lateral migration likely results from varying current directions and flow acceleration over shallower seabed. Sand ribbon migration should therefore a consideration in studies examining seabed change, particularly when they are formed over unconsolidated sediment.

Characteristics of hollow micron zero valent iron and its transport properties in groundwater: Effect of key engineering parameters and retention mechanism

In this study, a hollow micron zero-valent iron (H-mZVI) was synthesized, and its transport and retention property in saturated porous media was determined via a series of column experiments. Furthermore, the maximum migration distance (Lmax) and sedimentation rate coefficient (Kdep) models of H-mZVI in saturated porous media were established using statistical methods. The results revealed a distinct hollow structure in H-mZVI, with a density of 1.03±0.03 g/cm3, significantly lower than solid micron zero-valent iron (4.57±0.15 g/cm3). FTIR and XRD analyses indicated no formation of new functional groups on H-mZVI's surface, with iron being the main component. The column experiment demonstrated that the Lmax of H-mZVI in saturated porous media was 4.15 times that of solid micron zero-valent iron (mZVI) under the same conditions. The prediction model of Lmax aligned with the linear model, where Lmax correlated positively with particle size, injection velocity, and H-mZVI concentration, but inversely with ionic strength. Medium particle size and injection velocity were the main engineering parameters to control H-mZVI. The prediction model of Kdep accorded with the quadratic model, and an interaction was observed between medium particle size and injection velocity, which jointly affected the deposition rate of H-mZVI. Moreover, the single particle capture coefficient (η0) was hereby calculated and analyzed using the T-E theory. Interception primarily governed the precipitation of H-mZVI in saturated porous media, with gravity sedimentation contributing minimally to η0.

Kinetic simulation of uranium migration in granite fissure media of beishan, gansu, China: A case study based on the Laplace transform and inverse transform methods

Deep geological disposal is currently considered the most practical and feasible method for disposing high-level radioactive wastes (HLWs). One of its key scientific issues is the migration of nuclides in fissure media. However, studies on the migration of nuclides like U-238 are relatively limited. In this study, the granite rock masses in Beishan, Gansu were selected to construct a physical and mathematical model of U-238 migration using the Laplace transform and inverse transform methods. Based on the numerical methods, the kinetic migration of nuclide U-238 in the fissure media of granite was simulated, and the effects of parameters such as fissure width, hydraulic gradient, diffusible area ratio and rock porosity on the migration of U-238 were investigated. The following insights were obtained: (1) After 100,000 years, U-238 has a very limited diffusion depth in the matrix domain, with a diffusion range of only a few tens of millimeters, whereas it migrates relatively quickly in the fissure domain, with a maximum migration distance of about 1500 m. (2) Under the same migration time and distance, the relative concentration of nuclide U-238 in the fissure domain increases with larger gap width, hydraulic gradient, and diffusible area ratio, but decreases with higher rock porosity. (3) In the same time range, the rock masses with larger gap widths, hydraulic gradients, and diffusible area ratios have larger migration ranges, while those with higher porosities have smaller migration ranges. (4) While selecting a site for diposal of HLWs, it is recommended to choose rock masses in the granite area of Beishan with no fissures or few fissures; additionally, areas with smaller fissure widths, hydraulic gradients, and diffusible area ratios but higher rock porosity should be prioritized. This study can provide important theoretical support for understanding nuclide migration in the future geological disposal of HLWs.

Individual timing consistency across long-distance songbird migrations.

Migration timing in long-distance migratory birds plays an essential role in individual survival and fitness and is thought to be driven by circannual routines cued by photoperiod with some plasticity to environmental conditions. We examined the individual order of migration timing in purple martins (Progne subis), a neotropical migratory songbird that travels between breeding sites throughout eastern North America and nonbreeding sites in Brazil. Migration timing data were collected for 295 different individual purple martins over 9 years using light-level geolocators deployed at breeding sites across the range. We used linear mixed-effect models to examine the influence of the rank order of individual departure dates in one season on the rank order of four subsequent migration events while controlling for the effects of breeding latitude, sex, and age. Overall, we found evidence for consistent individual timing that can extend across 8 months and 12,000-24,000 km of migration. Individual rank order of migration timing in purple martins was generally conserved across migrations with consistent timings between fall departure dates from, and spring arrival dates to the breeding site the following year (0.28 ± 0.03, 95% CI 0.22-0.34), as well as at a finer scale across fall migration (0.33 ± 0.05, 95% CI 0.23-0.43), over the stationary nonbreeding period (0.39 ± 0.04, 95% CI 0.31-0.47), and across spring migration (0.03 ± 0.001, 95% CI 0.028-0.032). These results demonstrate that purple martins exhibit consistency in individual migration timing throughout the annual cycle that is likely driven by inherent individual circannual schedules. We additionally found that migration distance played a significant role, as the consistency of individual timing lessened over longer distances. Understanding how individual birds time migrations and if individuals are consistent between events can provide insight into how birds respond to shifts in their environment with climate change.

Dynamics of Daily Glioblastoma Evolution During Chemoradiation Therapy on the 0.35T Magnetic Resonance Imaging-Linear Accelerator

Glioblastoma changes during chemoradiation therapy are inferred from magnetic resonance imaging (MRI) before and after treatment but are rarely investigated due to logistics of frequent MRI. Using a combination MRI-linear accelerator (MRI-linac), we evaluated changes during daily chemoradiation therapy. Patients with glioblastoma were prospectively imaged daily during chemoradiation therapy on 0.35T MRI-linac and at 3 timepoints with and without contrast on standalone high-field MRI. Tumor or edema (lesion) and resection cavity dynamics throughout treatment were analyzed and compared with standalone T1 postcontrast (T1+C) and T2 volumes. Of 36 patients included in this analysis, 8 had cavity only, 12 had lesion only, and 16 had both cavity and lesion. Of these, 64% had lesion growth and 46% had cavity shrinkage during treatment on MRI-linac scans. The average MRI-linac migration distance was 1.3 cm (range, 0-4.1 cm) for lesion and 0.6 cm (range, 0.1-2.1 cm) for cavity. Standalone versus MRI-linac volumes correlated strongly with R2 values: 0.991 (T2 vs MRI-linac cavity), 0.972 (T1+C vs MRI-linac cavity), and 0.973 (T2 vs MRI-linac lesion). There was a moderate correlation between T1+C and MRI-linac lesion (R2 = 0.609), despite noncontrast MRI-linac inability to separate contrast enhancement from surrounding nonenhancing tumor and edema. From pretreatment to posttreatment in patients with all available scans (n = 35), T1+C and MRI-linac lesions changed together-shrank (n = 6), grew (n = 12), or unchanged (n = 8)-in 26 (74%) patients. Another 9 patients (26%) had growth on MRI-linac, although the T1+C component shrank. In no patient did T1+C lesion grow while MRI-linac lesion shrank. Anatomic changes are seen in patients with glioblastoma imaged daily on MRI-linac throughout the chemoradiation therapy course. As surgical resection cavities shrink, margins may be reduced to save normal brain. Patients with unresected or growing lesions may require margin expansions to cover changes. Limited volume glioblastoma boost trials could consider triggered gadolinium contrast administration for evaluation of adaptive radiation therapy when lesion growth is seen on noncontrast MRI-linac.

Photocatalytic reduction of the uranium(Ⅵ) by ultra-thin porous g-C3N4 nanosheets synthesized via microwave-assisted

Graphitic carbon nitride (g-C3N4) has garnered significant attention in the realm of photocatalytic reduction of U(Ⅵ) from aqueous solutions owing to its favorable bandgap and visible light responsiveness. Nevertheless, conventionally prepared bulk g-C3N4 suffers from limitations such as a small specific surface area and high recombination of photo-generated charges, consequently impeding the efficiency of photocatalytic reactions and hampering practical applications. To address these shortcomings, this study presents a novel approach wherein ultra-thin porous g-C3N4 nanosheets were successfully synthesized through the microwave-assisted calcination of urea in a single step. The resulting g-C3N4 nanosheets exhibit a multi-hollow mesh structure with a significantly enlarged specific surface area, the specific surface area and pore size of MCN90 are 170 m²/g and 17 nm, respectively, which are 2.3 times and 8 times that of the bulk g-C3N4. Photocatalytic experiments revealed that these ultra-thin porous nanosheets demonstrate superior performance in the reduction of U(Ⅵ) to U(Ⅳ), achieving a reduction rate of 100 % within 20 minutes for the optimal sample, as opposed to 78 % in 40 minutes for bulk g-C3N4. This enhanced photocatalytic activity can be primarily attributed to the unique ultra-thin porous nanosheet structure, which facilitates increased specific surface areas, improve photoelectric properties, and substantially shortened electron migration distances which reduce the recombination efficiency of photogenerated electrons and holes pairs. Consequently, these findings not only offer insights into the optimization of g-C3N4 for U(Ⅵ) reduction but also provide a valuable reference for the preparation of other two-dimensional ultra-thin porous materials aimed at similar applications.

Experimental study on the mechanical degradation of partially hydrolyzed polyacrylamide in pore throats

Understanding mechanical degradation is crucial for successful polymer flooding. In this study, the effects of stretching velocity, pore-throat ratio, polymer concentration, and migration distance on the mechanical degradation of HPAM were studied using a pore-throat model. Additionally, the contribution of tensile degradation at the entry point of the pore-throat model to the overall mechanical degradation was assessed through extrapolation. The experimental results indicate that tensile degradation at the entry point is the primary cause of the mechanical degradation, and its contribution is positively related to the flow rate. The mechanical degradation correlates positively with the stretching velocity (0.41 ∼ 6362s−1), pore-throat ratio (6 ∼ 60), and polymer concentration (500 ∼ 2200mg/L). Moreover, higher flow rate amplify the effects of changes in polymer concentration and pore-throat ratio on mechanical degradation. As the migration distance increases, the mechanical degradation initially increases and then stabilizes in the pore-throat model, whereas in the sand-packed model, the mechanical degradation continues to increase with increasing migration distance. This study enhances our understanding of polymer mechanical degradation and offers insights for developing strategies to reduce mechanical degradation and improve polymer-enhanced oil recovery.

Novel visible-light activated photocatalytic ultrafiltration membrane for simultaneous separation and degradation of emerging contaminants

Emerging contaminants (ECs) in secondary effluent of wastewater treatment plants (WWTPs) have received increasing attention due to their adverse effects on aquatic ecosystems and human health. Herein, visible-light responsive photocatalyst TM (TiO2 @NH2-MIL-101(Fe)) and resultant photocatalytic ultrafiltration (PUF, PVDF/TM) membrane were prepared to remove 32 typical compounds of antibiotics, 296 compounds of antibiotic resistance genes (ARGs), and their corresponding bacterial hosts. The construction of heterojunction photocatalyst promoted the electron transfer from NH2-MIL-101(Fe) to TiO2 and the formation of N-TiO2, enhancing visible-light (λ ≥ 420 nm) photocatalytic activity. With highly-hydrophilic surface and delicately-regulated pore structure, the initial water permeance of optimal PUF membrane significantly increased to 3912.2 L/m2/h at 1.0 bar. Meanwhile, membrane retention (via adsorption, electrostatic interaction, and steric hindrance) was improved due to the narrowed pore size, highly-negative surface charge and abundant functional groups. Additionally, hydroxyl radical (•OH) was the dominant active reactive oxygen species (ROS) for ECs degradation, and the narrowed pore structure could serve as microreactors to increase ROS concentration and reduce migration distance. Consequently, the removal efficiencies of antibiotics, bacteria and ARGs were 86.5 %, 91.4 % and 91.8 %, respectively. Overall, this novel visible-light-activated PUF membrane expands membrane application, and has great potential in ECs treatment.

Fast diffusion kinetics improves electron transfer regime selectivity to boost peroxymonosulfate activation

Electron transfer process (ETP) is barely influenced by half-life and migration distance in peroxymonosulfate (PMS) activation because it directly extracts electrons from pollutants for oxidation. However, the enhanced ETP selectivity is still challenging due to the poor mass transfer of PMS and pollutant. In this work, 2D porous N-doped carbon (PNC) with high reactant diffusion kinetics and multiple diffusion modes was designed to induce the interlayer confinement for efficient PMS activation with elevated ETP selectivity. Taking tetrabromobisphenol A as target pollutant, the confined PNC/PMS system achieved significantly enhanced PMS activation performance with the selectivity of ETP up to 97.8%. The vertical mass transfer of reactants into the inner interlayer space of the catalysts was proved to be promoted by the construction of molecule tunnels according to a diffusion model. Density functional theory calculations indicated that the subsequently triggered interlayer confinement facilitated the co-adsorption of PMS/pollutant on the interlayer surface and narrowed the energy gap of charge migration, resulting in enhanced PMS activation performance and ETP selectivity. Benefiting from the almost 100 % ETP selectivity, the confined PNC/PMS system exhibited substantially increased PMS utilization efficiency, admirable anti-interference ability towards various water matrices as well as long-term stability in a continuous-flow reactor. This work provides a new protocol for efficient and selective PMS activation by interlayer confinement in water remediation.

In situ XPS confirms enhanced hydrogen evolution in S-scheme heterojunction Cd0.8Mn0.2S/Cu2WS4 via charge vectorial separation

Solar-driven water splitting for hydrogen production is a vital approach to mitigating the energy crisis and achieving carbon neutrality and peak carbon emissions. Cd0.8Mn0.2S holds significant potential for photocatalytic hydrogen evolution but faces severe challenges due to photogenerated carrier recombination. To address this, we employed ultrasonic self-assembly to tightly couple Cu2WS4 nanosheets with Cd0.8Mn0.2S nanoparticles, forming an S-scheme heterojunction to reduce carrier recombination rates. In this configuration, Cd0.8Mn0.2S acts as the electron acceptor, and Cu2WS4 serves as the electron donor. The Cd0.8Mn0.2S/Cu2WS4 structure creates a closely spaced interface, providing the shortest transfer distance for electron migration. The S-scheme heterojunction strategy effectively suppresses the recombination of photogenerated carriers, promoting vectorial separation. Under 10 W white light irradiation, the Cd0.8Mn0.2S/Cu2WS4 composite photocatalyst exhibited remarkable hydrogen evolution activity, with a hydrogen production rate of 39.83 mmol g−1 h−1. This S-scheme heterojunction strategy lays the foundation for the structural design and large-scale application of high-activity visible-light photocatalysts.

Ultra-long-distance migration of the common Cuckoo (<i>cuculus canorus</i>, cuculiformes, cuculidae) from Kamchatka to Namibia

The application of high-tech methods for tracking birds, primarily satellite telemetry, has made it possible in a relatively short time to reveal real migratory routes and wintering areas for many bird species. In the Common cuckoo, whose breeding range extends over a vast territory from Portugal to Kamchatka, the migratory routes and wintering grounds have been well studied for a number of European populations, while the migration of Asian populations of this species is still not so well studied. In this work, we analyze satellite telemetry data obtained from four adult males of the Common cuckoo caught in early June 2017 during the nesting period on the Kamchatka Peninsula near the town of Yelizovo. The autumn migration of these birds started in August to early September. They crossed the Sea of Okhotsk (more than 1 000 km) and, without staying for a long time in the Khabarovsk Region, stopped in China (Sichuan, Hebei, Heilongjiang provinces), where they remained for a long time, from 32 to 52 days, moving around this country until October to November. In southern China, all three surviving males changed their SW direction of migration to almost western and flew crossing Myanmar and Bangladesh to India, where they stopped over for 24–34 days until November 10th or 29th. Then the birds crossed the Arabian Sea in 2–3 days overcoming the huge body of water of about 3 000 km in width without stop to land on the African continent (Somalia). Further migration of Kamchatka cuckoos passed through the countries of East Africa such as Ethiopia, Kenya, Tanzania, Malawi, Zambia or Zimbabwe, where they stayed from 2 to 11 days. Finally, all three individuals reached wintering areas in December, first in Botswana, then in Namibia. Thus, the duration of autumn migration of Kamchatka cuckoos varied from 106 to 123 days. During this time, they overcame a record distance of 17,340 km for land birds. The spring migration of two birds started on April 19th or 26th next year. They flew back using a similar route as in autumn. One individual crossed the Arabian Sea in early May, the other from May 20th to 22nd. Having reached India, one bird almost the same day arrived to Bangladesh and then to China. The other one stayed on the Hindustan Peninsula for 11 days, this being much shorter than in autumn. Unfortunately, only one male reached the nesting area in Kamchatka (May 31st). Apparently, the other one either died or lost the transmitter in China. The survived male returned to its former nesting area with high accuracy, its transmitter emitted signals until July 10th. The spring migration took the birds much less time (42 days) than in autumn (106–123 days). Thus, we recorded an ultra-long total distance of autumn and spring migration for a land bird species of almost 34,000 km from Kamchatka to Namibia and back.

Post-mortem to ante-mortem facial image comparison for deceased migrant identification

The identification of deceased migrants is a global challenge that is exacerbated by migration distance, post-mortem conditions, access to ante-mortem data for comparison, inconsistent international procedures and lack of communication between arrival and origin countries. Due to low technology requirements, fast speed analysis and ease of transferring digital data, facial image comparison is particularly beneficial in those contexts, especially in challenging scenarios when this may be the only initial ante-mortem data available to identify the deceased. The Facial Identification Scientific Working Group (FISWG) professional guidelines for facial image comparison were developed for living facial appearance, and, therefore, a tailored protocol for the application of post-mortem to ante-mortem facial image comparison was proposed and evaluated in this research. The protocol was investigated via an inter-observer and an accuracy study, using 29 forensic cases (2001–2020) from the University of Milan, provided by the Laboratory of Forensic Anthropology and Odontology. In order to replicate a migrant identification scenario, each post-mortem subject was compared to all 29 ante-mortem targets (841 comparisons). The protocol guided the practitioner through stages of facial image comparison, from broad (phase 1) to more detailed (phase 3), eventually leading to a decision of ‘exclusion’ or ‘potential match’ for each post-mortem to ante-mortem case (phase 4). In phase 4, a support scale was also utilised to indicate the level of confidence in a potential match. Each post-mortem subject could be recorded with multiple potential matches. The protocol proved to be useful guide for facial image comparison, especially for less experienced practitioners and the inter-observer study suggested good reproducibility. The majority (82–96%) of ante-mortem subjects were excluded at the first stage of the protocol, and 71 full post-mortem to ante-mortem facial image comparisons were carried out. On average, two or three potential matches were recorded for each post-mortem subject. The overall accuracy rate was 85%, with the majority (79%) of ante-mortem non-targets correctly excluded from the identification process. An increased number and quality of available ante-mortem images produced more successful matches with higher levels of support. All potential matches involving non-targets received low levels of support, and for 73% of the post-mortem subjects, the ante-mortem target was the only recorded potential match. However, two ante-mortem targets were incorrectly excluded (one at the first stage of the protocol) and therefore changes to the protocol were implemented to mitigate these errors. A full protocol and a practical recording chart for practitioner use is included with this paper.

Aspects of Movement Ecology and Habitat Use of Migratory Raptors Using Satellite Telemetry from India to Central Asia

Single individuals of the Greater Spotted Eagle (Clanga clanga), Indian Spotted Eagle (Clanga hastata), Tawny Eagle (Aquila rapax), Western Marsh Harrier (Circus aeruginosus), and two Pallid Harriers (Circus macrourus) were deployed with satellite transmitters in 2021 to study their home ranges, habitat associations, movement, and migration patterns. Data were collected for a combined number of 2291 days, providing 84,544 locations. Home ranges were calculated as kernel utilization distributions and expressed as 95% KDE and core areas as 50% KDE. Overall, eagles had larger home ranges (mean ± SD) of 942.70 ± 937.83 km2 compared to harriers, 43.84 ± 35.55 km2. Among eagles, the Greater Spotted Eagle had the largest home-range size of 2147.03 km2 calculated in Kazakhstan, while the female Pallid Harrier had the smallest home range of 5.74 km2 in Russia. Daily and monthly distances varied among eagles and harriers. The female Pallid Harrier covered the longest average monthly distance of 8585.43 ± 11,943.39 km, while the shortest monthly distance of 1338.22 ± 716.38 km was traveled by the Indian Spotted Eagle. All tagged birds migrated toward higher latitudes in the Northern hemisphere, except the Indian Spotted Eagle, which migrated to Pakistan. The male Western Marsh Harrier covered the longest migration distance in a shorter span of time, while the female Pallid Harrier took the longest to cover its migration distance. Overall, the daily distance covered during migration varied from 115.09 km traveled by the Indian Spotted Eagle to an overwhelming distance of 2035.85 km covered by the male Western Marsh Harrier. Scrubs, water bodies, croplands, and settlements were important habitat features associated with eagles, while croplands, open scrub, and built-up areas were associated with the female Pallid Harrier. The male Western Marsh Harrier was found to be primarily associated with saltpans and salt-affected areas having emergent vegetation. This study presents new insights into the movement and spatial ecology of long-distance migrant raptors that winter in Western India. We provide preliminary support for the use of the Western Circum–Himalayan Corridor as one of the important corridors of the Central Asian Flyway that warrants much appreciation among the current set of flyway corridors.

The Development of a Biomimetic Model of Bacteria Migration on Indwelling Urinary Catheter Surfaces.

The aim of this study was to develop a novel biomimetic in vitro extraluminal migration model to observe the migration of bacteria along indwelling urinary catheters within the urethra and assess the efficacy of a prototype chlorhexidine diacetate (CHX) coating to prevent this migration. The in vitro urethra model utilised chromogenic agar. A catheter was inserted into each in vitro urethra. One side of the urethra was then inoculated with bacteria to replicate a contaminated urethral meatus. The models were then incubated for 30 days (d), with the migration distance recorded each day. Four indwelling catheter types were used to validate the in vitro urethra model and methodology. Using the biomimetic in vitro urethra model, E. coli and S. aureus migrated the entire length of a control catheter within 24-48 h (h). In the presence of a prototype CHX coating, full migration of the channel was prevented for 30 d. The results of this study support the hypothesis that catheter-associated urinary tract infections (CAUTIs) could be prevented by targeting catheter-mediated extraluminal microbial migration from outside of the urinary tract into the bladder.

Flexible migration by woodland caribou in Ontario, Canada

AbstractRecent studies of ungulate movement ecology suggest that seasonal movement tactics often vary within a population. The forest‐tundra and forest‐dwelling ecotypes of woodland caribou (Rangifer tarandus caribou) in Ontario, Canada, are traditionally presumed to differ in migratory strategy; however, their potential for facultative migration, the practice of interannual switching between migratory and non‐migratory strategies, has yet to be explored. Understanding facultative migration, and any inherent variation and influences could help improve habitat management. We acquired global positioning system (GPS) telemetry‐based movement data from 109 radio‐collared caribou across the Hudson Bay lowlands between 2009 and 2019. We compared the data with estimates of vegetation density, snow cover, and human disturbance to identify environmental influences associated with the probability and magnitude of migration. We also compared seasonal resource selection between migratory and sedentary individuals. Caribou demonstrated plasticity in migration, with evidence of facultative migration by the forest‐tundra and the forest‐dwelling ecotypes. Variation in migration was likely a combination of local adaptation and acute response to changing environmental factors, particularly snow. Probability and distance of migration were positively correlated with snow, while distance also showed spatial dependency. Plasticity in migration has significant implications in relation to future shifts in climate and should be considered in relevant predictive analyses.

Mechanistic Insight into Ion Transport in Layered Materials for Sodium-Ion Rechargeable Batteries

As a feasible alternative to Li-ion batteries (LIBs), Na-ion batteries (SIBs) are an emerging energy storage solution for electric vehicles, electronic devices, and large grid level energy storage systems. The TMD (transition metal dichalcogenides) component MoS2 and the NASICON structured-type NaxTi2(PO4)3 are two materials of interest as next-generation SIB materials. MoS2 is a 2D layered material with a graphene-like structure that can be used as a high-capacity anode or Na-ion host material as well as an electrocatalyst. Our experiments on the Al-doped 1T phase of MoS2 on reduced graphene oxide (rGO) nanosheets support demonstrated good electrochemical performance, such as 450, 400, etc. mAh/g at current densities of 0.05, 0.1 A/g. Experiments further revealed that Na-ion intercalation supports increased interlayer distance in 1T Al-MoS2@rGO, resulting in a stable phase structure. Density functional theory (DFT)-based simulations are utilized to study the intercalation properties of Na+ ions, in addition to GITT, EIS, and CV analysis. In this study, the Na-ion diffusion mechanism for 1T Al-MoS2@rGO interface and Al-MoS2-MoS2 interlayer host structure is explored. According to the experiments, the host structure is doped with 5% Al at a specific stable site, and Na-ions are introduced to the interface and interlayer (an interlayer distance of 9.3 Å is chosen, as estimated by the experiments). The Na-ion is hopped in both structures, and activation energies (Eact) are calculated to be 57.9 kJ/mol and 40.3 kJ/mol in the 1T Al-MoS2@rGO interface at migration distances of 0-2 Å and 2-4 Å, respectively. The related Na-ion diffusion coefficients are computed using an Arrhenius type fit to be in the order of 10-13 cm2/s and 10-10 cm2/s. Similarly, the Na-ion activation energy barriers in the 1T Al-MoS2-MoS2 interlayer are estimated to be between 49.8 and 59.6 kJ/mol, with related diffusivity ranging between 10-11 and 10-13 cm2/s. The outcomes of the DFT simulations are consistent with those of our experiments. The Na-ion transport properties in the NaTi2(PO4)3 bulk structure via the Na-ion vacancy assisted mechanism are investigated using MD simulations and DFT. The self-diffusion coefficients (DNa+) of bulk are examined, and then the lattice strain effect is proposed to alter its transport properties by introducing the lattice strain in uniaxial (x, y, z) and biaxial (xy, xz, yz) directions, and the changes are compared for strained and unstrained structure. In comparison to the unstrained structure at 323K, a significant improvement by 1-2 order change in DNa+ values (10-8 cm2/s - 10-10 cm2/s) is measured. DFT is also used to investigate the diffusion mechanisms along the various planes (line [001], [100], and [010]) of the bulk NaTi2(PO4)3 structure and Eact is determined along those directions, respectively. The values obtained are consistent with the experimental value ranges obtained for similar materials. In addition, a mixed ion-system is represented by inserting Li-ions at the surface of a NaTi2(PO4)3 structure, yielding the formula LixNay-xTi2(PO4)3. The sluggish kinetics of Li-ion in the NaTi2(PO4)3 structure were proposed by MD analysis. This corresponds well with experimental data that the NaTi2(PO4)3 framework exhibits preferred Na-ion insertion when cycling in mixed-ion electrolytes of varied concentrations, implying slow diffusion of Li-ions in the bulk Li+/Na+ mixed-ion crystal.

The effect of surveillance fishing on migration distance of Atlantic Salmon during the spawning period

AbstractObjectiveSurveillance fishing surveys can be performed to estimate the proportion of farmed salmon represented in the spawning stock of native Atlantic Salmon Salmo salar populations. These surveys take place after the recreational fishing period and therefore closer to the spawning period than the open recreational fishing season. Although catch‐and‐release angling has been demonstrated to affect salmon migration during the summer months, surveillance fishing that is conducted close to the spawning time could have more severe effects.MethodsTo test this, the migration distance of Atlantic Salmon (n = 74) caught in the Orkla River, Norway, was tracked by use of radiotelemetry. One group was tagged during the regular fishing season in the summer (control group), whereas another group was tagged in autumn during surveillance fishing (surveillance group).ResultSixty‐one salmon remained for analysis after we excluded fish that were recaptured, died, or migrated to other rivers. Relocation of the salmon during autumn (October 11–31) was used to compare movements and test for differences in migration using negative binomial regression because distances were nonnegative integers. During the tracking period, the surveillance group moved 12 ± 14 km (mean ± standard deviation) and the control group moved 13 ± 15 km; both groups moved 1 ± 2 km/day on average. There was no evidence that surveillance fishing impacted movement of the salmon compared to controls. However, one salmon died after tagging and three were not released due to injuries; total mortality of 9% during surveillance fishing could be unsustainable for smaller populations. Consequently, factors such as surveillance sample size, the status of the salmon population, and the population size should be assessed for each river individually when deciding the necessity of and approach to surveillance fishing.ConclusionThe results support existing recommendations to use careful handling and to end surveillance at least 2 weeks prior to the expected onset of spawning, thus providing a sufficiently long period for recovery after surveillance fishing.

Abstract We089: Numb Family Proteins in Epicardium Regulate Epicardial Cells Differentiation and Ventricular Patterning During Development

Background: Numb Family Proteins (NFPs), specifically two mammalian homologs Numb (denoted by Nb ) and Numblike (denoted by Nl ), have been evident to regulate essential cardiac functions during development. Previous studies reported NFPs as integral for epicardial cells (EpiCs) epithelial mesenchymal-transition (EMT). However, whether NFPs in epicardium regulate EpiCs differentiation to affect cardiac morphogenesis have not been explored. In this study, we investigated how NFPs in epicardium regulate EpiCs EMT and differentiation to modulate cardiac development and subsequently affect cardiac maintenance in adult stages. Method: Using mCherry:Numb knockin mouse model we observed enrichment of Numb in epicardium. We deleted Nb and Nl in epicardium via Tbx18 Cre/+ lineage and refer to this as EDKO. We harvested hearts at embryonic day 15.5/18.5 and assessed morphological and mechanistic differences between control and EDKOs. Conventional and Speckle tracking Echocardiography were used to examine adult heart structure and functions. Results: Our findings revealed that EDKO embryonic hearts display specific morphology with extended left ventricles. We found a surprising difference between female and male EDKOs in terms of survival to adulthood. Reduced EpiCs EMT and Cardiac Fibroblasts (CFs) migration distances, changes in CFs distribution have been observed in EDKO developing hearts. Reduced expression of smooth muscle cells (SMCs) and pericytes also was noticed in EDKOs. Strikingly, EDKO embryonic hearts show defects in ventricular compaction, ventricular wall patterning and in cell proliferation. Furthermore, when survived to adult stage, EDKO hearts revealed significant structural and functional changes over their aging. While digging into regulatory pathways, we found changes in Fibroblast growth factor receptors (Fgfrs)/p-Erk pathway and in activation of Notch1 in EDKO hearts. Conclusion: NFPs in epicardium regulate EpiCs differentiation into CFs and SMCs, and regulate ventricular wall morphogenesis during development. NFPs are also required to maintain cardiac structure and function at adult stages. Fgfrs/p-Erk pathway and Notch1 could be the possible mechanism behind cardiac morphogenetic regulation by NFPs in epicardium. Future aims: Further studies will identify downstream targets of NFPs’ regulation of EpiCs differentiation and ventricular wall patterning in embryonic hearts, and mechanistic pathways of epicardial NFPs’ role in adult hearts.

Formononetin alleviates thermal injury-induced skin fibroblast apoptosis and promotes cell proliferation and migration

The aim of this study was to explore the effect and mechanism of formononetin (FMNT) in thermal-injured fibroblast proliferation, apoptosis, and oxidative stress. After the thermal injury, HSF cells showed inhibited proliferation, migration, and ECM synthesis, whereas increased apoptosis, ROS production, and inflammation. Specifically, after thermal injury, cell viability, migration distance, and protein levels of Collage I, Collage III, α-SMA, MMP1, and MMP3 were reduced; cell apoptosis rate and TUNEL-positive cell numbers were increased; the levels of Bax and Cleaved caspase-3 showed to be elevated, while Bcl-2 level showed to be reduced. Moreover, the thermal injured-HSF cells showed increased levels of ROS, MDA, LDH, TNF-α, and IL-1β, and decreased GSH, SOD, GSH-Px, and CAT. FMNT levels can partially eliminate the effects of thermal injury on HSF cells, as shown by promoting thermal injured-HSF cell proliferation and migration, and inhibiting cell apoptosis, ROS production, and inflammation. FMNT exerted no significant effect on normal HSF cells. Additionally, the level of the P13K/AKT/mTOR signaling-related proteins (p-P13K, p-AKT, and p-mTOR) was reduced in thermal injured-HSF cells, whereas FMNT could promote p-P13K, p-AKT, and p-mTOR levels. FMNT can partially alleviate the thermal injury-induced inhibition of fibroblast proliferation and migration; FMNT also inhibited the apoptosis, ROS level, and inflammation in thermal-injured cells. The effects of FMNT may be mediated by regulating the P13K/AKT/mTOR pathway.