Similarities In Dynamics Research Articles

Changes in incidence and clinical features of tuberculosis with regard to the COVID-19 outbreak in Southern Iran

IntroductionTuberculosis (TB), caused by Mycobacterium tuberculosis, remains a significant global health threat. It results in substantial mortality and may be underrecognized due to insufficient screening and diagnostic challenges. Furthermore, TB’s impact is closely linked to complex socioeconomic and healthcare factors. The COVID-19 pandemic has exacerbated these challenges due to similarities in clinical presentation and transmission dynamics with TB. Socioeconomic factors such as limited access to healthcare services, resource constraints, and social stigma further complicate TB management. Historically, TB faced increased burdens during natural disasters, wars, and pandemics. This study analyzes TB incidence changes, emphasizing the crucial need for timely diagnosis within the context of COVID-19 measures.MethodThis cross-sectional study, conducted at Shiraz’s TB referral center in Southern Iran, covered the period from January 1, 2018, to December 31, 2022. We analyzed patient data, including epidemiological and demographic factors, clinical and radiological features, and treatment outcomes. Data were compared between the pre-COVID-19 pandemic era and the COVID-19 pandemic era (from March 2020), using standard and regression analyses. A P-value of less than 0.05 was considered statistically significant.ResultsWe analyzed 388 TB patients with a mean age of 48.38 ± 20.53 years, including 264 pulmonary cases (68.0%). The highest incidence of TB was recorded in 2019, representing 27.6% of the cases. During the COVID-19 era, logistic regression analysis identified significant associations with higher education levels (P = 0.032; OR = 1.380; 95% CI: 1.028–1.851), a decrease in symptoms such as sputum production (P = 0.004; OR = 0.342; 95% CI: 0.166–0.705) and chills (P = 0.036; OR = 0.282; 95% CI: 0.087–0.919), and an increase in symptoms of fatigue (P = 0.006; OR = 2.856; 95% CI: 1.358–6.005).ConclusionThe COVID-19 pandemic has had a prolonged impact on TB cases in our country, resulting in a reduction in reported cases due to challenges in quarantine and screening. However, it has also led to a shift in TB patterns and a potential increase in latent TB cases and future mortality rates. Addressing the repercussions requires enhanced control strategies, prioritized service delivery, and secured funding for intensified case finding, expanded contact-tracing, community engagement, digital health tools, and uninterrupted access to medications.

MDMA for treatment of PTSD and neurorehabilitation in military populations.

Neurorehabilitation in military populations is complicated by higher rates of PTSD and unique characteristics of military institutions. These factors can adversely impact the patient-therapist therapeutic alliance and engagement with the rehabilitation process leading to poorer outcomes. MDMA is a non-classical psychedelic with pro-social and fear regulating properties. MDMA-assisted therapy is being explored as a novel treatment for PTSD that potentially offers rapid symptom improvement and enhances therapeutic alliance. A review of MDMA-assisted therapy for PTSD is provided in the context of neurorehabilitation in military populations. The molecular mechanism of MDMA is outlined and a novel application of MDMA for neurorehabilitation is proposed. This is an expert review and synthesis of the literature. Results from late-stage clinical trials suggest MDMA-assisted therapy for PTSD would be of particular benefit for military populations with PTSD. The unique pro-social properties of MDMA could be leveraged to enhance the therapeutic alliance and patient engagement during neurorehabilitation. The unique qualities and benefits of MDMA and MDMA-assisted therapy for PTSD suggest relevant application in military personnel undergoing neurorehabilitation. There are many similarities in patient-therapist dynamics in PTSD treatment and neurorehabilitation. The properties of MDMA which enhance therapeutic alliance, downregulate fear, and increase cognitive flexibility would potentially benefit both military personnel with and without PTSD undergoing neurorehabilitation.

Disparities and similarities in the spatiotemporal dynamics of flash and slow droughts in China

Climate warming has induced significant transitions from slowly-developing droughts to rapidly-developing flash droughts in China, causing broad impacts on ecosystems, hydrological regimes, and society. To date, most studies focused on temporal evolution of flash droughts, while neglected the spatial expansion which is essential for understanding their origins and spatial propagations, especially for mega flash droughts. Based on the long-term (1940–2022) dataset of the 5th generation of the European ReAnalysis, here we use a three-dimensional drought identification method to analyze the disparities and similarities in the spatiotemporal dynamics of flash and slow droughts at the subseasonal time scale over China. Although half of the flash and slow droughts are characterized by small areas (<5000 km2), short durations (30–45 d) and short propagation distances of drought centroids (<50 km), the probability of large-scale (>30 000 km2) flash droughts with long propagation distances (>100 km) is twice of slow droughts. Moreover, global and local spatial autocorrelation analyses reveal that South China (SC) and North China are hotspots for large-scale flash and slow droughts, respectively, and they both show significant increasing trends (0.11–0.12 events/decade) during 1940–2022. Without these large-scale droughts, there is no obvious difference in spatial distributions of the frequency of flash and slow droughts. Despite disparities, both large-scale flash and slow droughts show a preferential westward propagation, with 60%–67% of the movements consistent with the pathways of atmospheric water vapor flux anomaly. Our study urges the understanding and prevention of large-scale flash drought events, especially in SC.

Morphometry of Tidal Meander Cutoffs Indicates Similarity to Fluvial Morphodynamics

AbstractSinuous channels wandering through coastal wetlands have been thought to lack lateral‐migration features like meander cutoffs and oxbows, spurring the broad interpretation that tidal and fluvial meanders differ morphodynamically. Motivated by recent work showing similarities in planform dynamics between tidal and fluvial meandering channels, we analyzed meander neck cutoffs from diverse tidal and fluvial environments worldwide, and show that tidal cutoffs are widespread. Their perceived paucity stems from pronounced channel density and hydrological connectivity in coastal wetlands, comparatively small size of most tidal channels, and typically dense vegetation cover. Although these factors do not efface tidal meander cutoffs, they collectively inhibit oxbow formation and make tidal cutoffs ephemeral features that can escape detection. We argue that similar morphodynamic processes drive cutoff formation in tidal and fluvial landscapes, with differences arising only during post‐cutoff evolution. Such process similarity has important implications for understanding coastal wetland ecomorphodynamics and predicting their long‐term evolution.

Duration of phenophases ofSyringa sweginzowiiKoehne &amp; Lingelsh. andSyringa komarowiiC.K.Schneid. sections Villosae C.K.Schneid and features of their growth in the conditions of the Middle Urals

The article is devoted to the study of phenophases ofSyringa sweginzowiiKoehne &amp; Lingelsh. =Syringa tomentellasubsp.sweginzowiiandSyringa komarowiiC.K.Schneid. section Villosae C.K.Schneid in the collection of the Botanical Garden of the Ural Branch of the Russian Academy of Sciences. The patterns of growth of annual vegetative and generative shoots have been established. The average duration of growth and development of branching shoots is 133 days. Features of the mechanisms of apical growth of vegetative and generative shoots are manifested in the form of differences and similarities in seasonal dynamics. Apical growth has similar seasonal dynamics curves in shape and is characterized by synchrony in all species, which can indicate the similarity of their mechanisms in different shoots. There are specific characteristics in the growth rate of lilacs; of the two species, Zvegintsov’s lilac is characterized by a high rate of apical and radial growth.

Effect of wind turbulences on the burning of a rockrose hedge

With climate change, complex fire scenarios at Wildland Urban Interfaces (WUI) have become a growing concern for authorities worldwide. Such scenarios involve unfavorable wind conditions, which greatly increase the fire spread near communities and makes the intervention of firefighters even more complex. To design effective fire safety regulations to protect communities, it is important to have a clear understanding of the role of wind in the burning of vegetation to help identify the vectors of fire spread within the defensible zone. In this context, this paper attempts to relate the properties of the flames generated by the burning of a reconstructed rockrose hedge to the atmospheric wind turbulence using four field-scale experiments. The experimental setup includes 3 visible cameras to record the flame geometry, extracted by post-processing; 3 pairs of radiant and total heat fluxes to record the heat fluxes downstream of the hedge, and an anemometer to measure the wind speed and direction. The results show that the wind at the experimental site is composed of wall-bounded turbulent structures coupled with strong and short intermittent events such as gusts. Regarding the fire, the four replicates show similarities in phase durations and dynamics, but revealed dependencies on Reynolds number and turbulent kinetic energy when averaging over the fully developed flame phase. In addition, a slight flapping motion of the ensemble flame was observed and associated with wave numbers of the order of the turbulent cascade in the kinetic energy power spectra. Finally, the analysis of wind and fire intermittencies revealed that strong and short wind events generate large fluctuations of flame geometry and received heat fluxes that increase with the characteristic time of the event considered.

Collisionless Accretion onto Black Holes: Dynamics and Flares.

We study the accretion of collisionless plasma onto a rotating black hole from first principles using axisymmetric general-relativistic particle-in-cell simulations. We carry out a side-by-side comparison of these results to analogous general-relativistic magnetohydrodynamic simulations. Although there are many similarities in the overall flow dynamics, three key differences between the kinetic and fluid simulations are identified. Magnetic reconnection is more efficient, and rapidly accelerates a nonthermal particle population, in our kinetic approach. In addition, the plasma in the kinetic simulations develops significant departures from thermal equilibrium, including pressure anisotropy that excites kinetic-scale instabilities, and a large field-aligned heat flux near the horizon that approaches the free-streaming value. We discuss the implications of our results for modeling event-horizon scale observations of Sgr A* and M87 by GRAVITY and the Event Horizon Telescope.

Plan‐Form Evolution of Drainage Basins in Response to Tectonic Changes: Insights From Experimental and Numerical Landscapes

AbstractSpatial gradients in rock uplift control the relief and slope distribution in uplifted terrains. Relief and slopes, in turn, promote channelization and fluvial incision. Consequently, the geometry of drainage basins is linked to the spatial pattern of uplift. When the uplift pattern changes, basin geometry is expected to change by migrating water divides. However, the relations between drainage pattern and changing uplift patterns remain elusive. The current study investigates the plan‐view evolution of drainage basins and the reorganization of drainage networks in response to changes in the spatial pattern of uplift, focusing on basin interactions that produce globally observed geometrical scaling relations. We combine landscape evolution experiments and simulations to explore a double‐stage scenario: the emergence of a fluvial network under block uplift conditions followed by tilting that forces drainage reorganization. We find that the globally observed basin spacing ratio and Hack's parameters emerge early in the basin formation and are maintained by differential basin growth. In response to the tilting, main divide migration induces basin size changes. However, basins' scaling relations are mostly preserved within a narrow range of values, assisted by incorporation and disconnection of basins to and from the migrating main divide. Lastly, owing to similarities in landscape dynamics and response rate to uplift pattern changes between experiments and simulations, we conclude that the stream power incision model can represent fluvial erosion processes operating in experimental settings.

External and Domestic Drivers of Nuclear Trilemma in Southern Asia: China, India, and Pakistan

ABSTRACT This paper discusses both the external and domestic drivers of the nuclear trilemma in Southern Asia that involves China, India and Pakistan. It seeks to untangle the complexity of the dyad and the triangular nature of the relationships between the three countries and highlights major differences as well as similarities in the nuclear dynamics. It identifies and examines the internal dynamics of the China–India and India–Pakistan conflicts and explores how domestic drivers such as nationalism, public opinions, and civil–military relations either mitigate or exacerbate nuclear risks in a region marked by perennial disputes, emerging rivalry, and long-standing extra-regional interferences. Against these backgrounds, the paper addresses the central theme of the nuclear trilemma between China, India, and Pakistan by looking at causes of instability, risks of conflicts and escalation to nuclear use, and prospects of restraint and risk reduction, including the development and implementation of confidence-building measures and nuclear risk reduction mechanisms.

Rain Forest Fragmentation and Environmental Dynamics on Nosy Be Island (NW Madagascar) at 1300 cal BP Is Attributable to Intensified Human Impact

Madagascar houses one of the Earth’s biologically richest, but also one of most endangered, terrestrial ecoregions. Although it is obvious that humans substantially altered the natural ecosystems during the past decades, the timing of arrival of early inhabitants on Madagascar as well as their environmental impact is still intensively debated. This research aims to study the beginning of early human impact on Malagasy natural ecosystems, specifically on Nosy Be island (NW Madagascar) by targeting the sedimentary archive of Lake Amparihibe, an ancient volcanic crater. Based on pollen, fungal spore, other non-pollen palynomorph, charcoal particle and diatom analyses combined with high-resolution sediment-physical and (in)organic geochemical data, paleoenvironmental dynamics during the past three millennia were reconstructed. Results indicate a major environmental change at ca. 1300 cal BP characterized by an abrupt development of grass (C4) dominated and fire disturbed landscape showing the alteration of natural rain forest. Further, increased soil erodibility is suggested by distinct increase in sediment accumulation rates, a strong pulse of nutrient input, higher water turbidity and contemporaneous increase in spores of mycorrhizal fungi. These parameters are interpreted to show a strong early anthropogenic transformation of the landscape from rain forest to open grassland. After ca. 1000 cal BP, fires remain frequent and vegetation is dominated by forest/grassland mosaic. While natural vegetation should be dominated by rain forest on Nosy Be, these last results indicate that human continuously impacted the landscapes surrounding the lake. At a local scale, our data support the “subsistence shift hypothesis” which proposed that population expansion with development of herding/farming altered the natural ecosystems. However, a precise regional synthesis is challenging, since high-resolution multi-proxy records from continuous sedimentary archives as well as records located further north and in the hinterland are still scarce in Madagascar. The lack of such regional synthesis also prevents precise comparison between different regions in Madagascar to detect potential (dis)similarities in climate dynamics, ecosystem responses and anthropogenic influences at the island’s scale during the (late) Holocene.

Motion-Driven Visual Tempo Learning for Video-Based Action Recognition.

Action visual tempo characterizes the dynamics and the temporal scale of an action, which is helpful to distinguish human actions that share high similarities in visual dynamics and appearance. Previous methods capture the visual tempo either by sampling raw videos with multiple rates, which require a costly multi-layer network to handle each rate, or by hierarchically sampling backbone features, which rely heavily on high-level features that miss fine-grained temporal dynamics. In this work, we propose a Temporal Correlation Module (TCM), which can be easily embedded into the current action recognition backbones in a plug-in-and-play manner, to extract action visual tempo from low-level backbone features at single-layer remarkably. Specifically, our TCM contains two main components: a Multi-scale Temporal Dynamics Module (MTDM) and a Temporal Attention Module (TAM). MTDM applies a correlation operation to learn pixel-wise fine-grained temporal dynamics for both fast-tempo and slow-tempo. TAM adaptively emphasizes expressive features and suppresses inessential ones via analyzing the global information across various tempos. Extensive experiments conducted on several action recognition benchmarks, e.g. Something-Something V1&V2, Kinetics-400, UCF-101, and HMDB-51, have demonstrated that the proposed TCM is effective to promote the performance of the existing video-based action recognition models for a large margin. The source code is publicly released at https://github.com/zphyix/TCM.

Complications in the Interpretation of F8T2 Spectra in Terms of Morphology.

Photophysical properties of conjugated polymers strongly correlate with chain morphology and interactions between chains. Here, we observed two characteristic types of spectra of poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(bithiophene)] (F8T2) in both single-chain and bulk cases. Despite the similarities in emission spectra, fluorescence dynamics and intensities corresponding to each type of spectrum are radically different in these cases. We hypothesize that the origin of the spectrum with a suppressed 0-0 vibronic band in photoluminescence is chain bending in the single-chain experiments, while the same phenomenon is caused by interchain aggregation in bulk samples. We propose a microscopic interpretation of the single-chain result in terms of bending that we expect to be characteristic of flexible conjugated polymers with five-membered rings. Caution must be exercised in drawing inferences about the meaning of single-chain spectra by analogy with bulk data.

Disentangling temporal food web dynamics facilitates understanding of ecosystem functioning.

Studying how food web structure and function vary through time represents an opportunity to better comprehend and anticipate ecosystem changes. Yet, temporal studies of highly resolved food web structure are scarce. With few exceptions, most temporal food web studies are either too simplified, preventing a detailed assessment of structural properties or binary, missing the temporal dynamics of energy fluxes among species. Using long-term, multi-trophic biomass data coupled with highly resolved information on species feeding relationships, we analysed food web dynamics in the Gulf of Riga (Baltic Sea) over more than three decades (1981-2014). We combined unweighted (topology-based) and weighted (biomass- and flux-based) food web approaches, first, to unravel how distinct descriptors can highlight differences (or similarities) in food web dynamics through time, and second, to compare temporal dynamics of food web structure and function. We find that food web descriptors vary substantially and distinctively through time, likely reflecting different underlying ecosystem processes. While node- and link-weighted metrics reflect changes related to alterations in species dominance and fluxes, unweighted metrics are more sensitive to changes in species and link richness. Comparing unweighted, topology-based metrics and flux-based functions further indicates that temporal changes in functions cannot be predicted using unweighted food web structure. Rather, information on species population dynamics and weighted, flux-based networks should be included to better comprehend temporal food web dynamics. By integrating unweighted, node- and link-weighted metrics, we here demonstrate how different approaches can be used to compare food web structure and function, and identify complementary patterns of change in temporal food web dynamics, which enables a more complete understanding of the ecological processes at play in ecosystems undergoing change.

Исследование влияния предыстории деформирования на усталостное сопротивление бетона и фибробетона

An experimental and analytical study into the impact of deformation history on the deformation re-sponse of conventional and fibre-reinforced concrete was conducted. Experiments included monoton-ic quasi-static and dynamic tests of two series of samples. Ultrasonic and gravimetric homogeneity con-trol by mass was performed prior to mechanical tests. Prismatic reference samples were tested under uniform deformation velocity (0.004 mm/s) on an Instron 5989 complex with automatic recording of deformations, loadings, time and absorption energy. Deformations were measured in both directions at the total base using system (Instron) extensometers. The paper analyses the experimental results on the fatigue behaviour of conventional and polypropylene fibre-reinforced concrete subjected to two-stage cyclic stress with various amplitudes. Parameters of linear and bulk deformability were used as a characteristic under control for low-cyclic fatigue. The fatigue resistance of concrete and fibre-reinforced concrete was assessed by comparing the corresponding characteristics of sample defor-mation under various modes of cyclic action. Relative similarities in the parameter dynamics of con-trolled low-cyclic fatigue show significant differences in quantitative values. It was established that the frequency and sequence of moderate (з ≤ Rнcrc) actions have a limited effect on fatigue resistance. The composite behaviour at high-level cyclic stress depends on the deformation history.

Multiplex Recurrence Network Analysis of Inter-Muscular Coordination During Sustained Grip and Pinch Contractions at Different Force Levels

Production of functional forces by human motor systems require coordination across multiple muscles. Grip and pinch are two prototypes for grasping force production. Each grasp plays a role in a range of hand functions and can provide an excellent paradigm for studying fine motor control. Despite previous investigations that have characterized muscle synergies during general force production, it is still unclear how intermuscular coordination differs between grip and pinch and across different force outputs. Traditional muscle synergy analyses, such as non-negative matrix factorization or principal component analysis, utilize dimensional reduction without consideration of nonlinear characteristics of muscle co-activations. In this study, we investigated the novel method of multiplex recurrence networks (MRN) to assess the inter-muscular coordination for both grip and pinch at different force levels. Unlike traditional methods, the MRN can leverage intrinsic similarities in muscle contraction dynamics and project its layers to the corresponding weighted network (WN) to better model muscle interactions. Twenty-four healthy volunteers were instructed to grip and pinch an apparatus with force production at 30%, 50%, and 70% of their respective maximal voluntary contraction (MVC). The surface electromyography (sEMG) signals were recorded from eight muscles, including intrinsic and extrinsic muscles spanning the hand and forearm. The sEMG signals were then analyzed using MRNs and WNs. Interlayer mutual information ( I ) and average edge overlap ( ω ) of MRNs and average shortest path length ( L ) of WNs were computed and compared across groups for grasp types (grip vs. pinch) and force levels (30%, 50% and 70% MVC). Results showed that the extrinsic, rather than the intrinsic muscles, had significant differences in network parameters between both grasp types ( ), and force levels ( ), and especially at higher force levels. Furthermore, I and ω were strengthened over time ( ) except with pinch at 30% MVC. Results suggest that the central nervous system (CNS) actively increases cortical oscillations over time in response to increasing force levels and changes in force production with different sustained grasping types. Muscle coupling in extrinsic muscles was higher than in intrinsic muscles for both grip and pinch. The MRNs may be a valuable tool to provide greater insights into inter-muscular coordination patterns of clinical populations, assess neuromuscular function, or stabilize force control in prosthetic hands.

Understanding personalized dynamics to inform precision medicine: a dynamic time warp analysis of 255 depressed inpatients

BackgroundMajor depressive disorder (MDD) shows large heterogeneity of symptoms between patients, but within patients, particular symptom clusters may show similar trajectories. While symptom clusters and networks have mostly been studied using cross-sectional designs, temporal dynamics of symptoms within patients may yield information that facilitates personalized medicine. Here, we aim to cluster depressive symptom dynamics through dynamic time warping (DTW) analysis.MethodsThe 17-item Hamilton Rating Scale for Depression (HRSD-17) was administered every 2 weeks for a median of 11 weeks in 255 depressed inpatients. The DTW analysis modeled the temporal dynamics of each pair of individual HRSD-17 items within each patient (i.e., 69,360 calculated “DTW distances”). Subsequently, hierarchical clustering and network models were estimated based on similarities in symptom dynamics both within each patient and at the group level.ResultsThe sample had a mean age of 51 (SD 15.4), and 64.7% were female. Clusters and networks based on symptom dynamics markedly differed across patients. At the group level, five dynamic symptom clusters emerged, which differed from a previously published cross-sectional network. Patients who showed treatment response or remission had the shortest average DTW distance, indicating denser networks with more synchronous symptom trajectories.ConclusionsSymptom dynamics over time can be clustered and visualized using DTW. DTW represents a promising new approach for studying symptom dynamics with the potential to facilitate personalized psychiatric care.

Nearshore paleoceanogaphic conditions through the Holocene: Shell carbonate from archaeological sites of the Atacama Desert coast

From the southern coast of Peru to the central-north coast of Chile (18°-31°S) previous evidence suggests that wide variations in sea surface temperature (SST) over the Holocene may be associated with changes in coastal upwelling regimes along the region. Support for spatial contrasts and similarities in oceanographic dynamics comes from earlier work at both extremes of the region. Using a 12 kyr record derived from shell midden archaeological sites around Taltal Chile (25°S), we show that changes in the region are not necessarily consistent with a simple latitudinal gradient. Using δ13C and δ18O isotopic records from archaeological carbonate shells of the keyhole limpet Fissurella maxima we find that cold SST during the Early Holocene was associated with more negative δ13C values in agreement with observations from southern Peru. Warmer waters during the beginning of the Middle Holocene, had positive δ13C values, differentiating them from southern Peru and central-north Chile records. The rest of the Middle Holocene showed a decreasing SST accompanied by negative δ13C values, and after 4000 cal yr BP, the Late Holocene showed a progressive increase in SST and positive δ13C values. Finally, modern carbonate shells of F. maxima indicate a situation not observed throughout the Holocene period: warm SST is associated with negative δ13C values, in line with results on modern shells from southern Peru and modern oceanographic patterns that indicate an intensification of coastal upwelling with events of warm water intrusion. Our results show that the southern coast of the Atacama Desert experienced important fluctuations in SST and upwelling conditions during the Holocene, which may have affected the distribution of nearshore fisheries along the Northern Coast of Chile.

Lycopodium root meristem dynamics supports homology between shoots and roots in lycophytes.

Roots have played a pivotal role in the conquest of land by vascular plants, yet their origin has remained enigmatic. Palaeobotanical evidence suggests that roots may have originated from subterranean shoots in some lycophyte species. If this hypothesis is correct, it would follow that the roots and shoots of extant lycophytes share fundamental developmental mechanisms. We tracked meristem dynamics in root and shoot apices of Lycopodium clavatum using a thymidine analogue and expression patterns of histone H4, respectively. Then we compared the meristem dynamics of roots and shoots to identify developmental similarities. Both apical meristems contained a quiescent tissue characterised by a low frequency of cell division. Actively dividing cells appeared in the quiescent tissue during dichotomous branching of both roots and shoots. As a result, the parental meristem divides into two daughter meristems, which give rise to new root or shoot apices. These striking similarities in meristem dynamics provide new neobotanical data that support the shoot-origin hypothesis of lycophyte roots. Although Lycopodium roots may have originated from subterranean shoots of Devonian lycophytes, these shoots may have changed into root-bearing axes in other extant lycophyte lineages.

Protozoan and Helminth Infections of Aviary-Reared Alectoris rufa (Galliformes: Phasianidae) before Releasing for Hunting in the Czech Republic: Infection Dynamics and Potential Risks.

Age-related dynamics of protozoan and helminth infections in the red-legged partridge, Alectoris rufa, were studied in an intensive breeding aviary in the Czech Republic before releasing birds for hunting purposes. Pooled fecal samples (n = 900) were examined over 3 rearing seasons (2012-2014). A total of 4 protozoan species, Cryptosporidium baileyi, Cryptosporidium meleagridis, Eimeria kofoidi, and Eimeria legionensis, and 4 helminths, Capillaria phasianina, Eucoleus perforans, Heterakis gallinarum, and Syngamus trachea, was found. The most common parasite was S. trachea (prevalence 20-26%) in dead birds (n = 99), which represents a high risk for breeders. Co-occurrence of protozoans and helminths indicated similarities in infection dynamics throughout the 3 breeding seasons. Mixed infections of Cryptosporidium baileyi and C. meleagridis with other parasitic species are reported for the first time. Our findings provide new insights into breeding of A. rufa and may help to improve the efficacy of disease control strategies and prevention, especially with the potential for spreading of parasitic infections to wildlife through released birds into open areas.

The study of subduction channels: Progress, controversies, and challenges

The subduction channel is defined as a relatively thin and weak zone with coherent kinematics between the descending and overriding plates during subduction. The materials in the channel, showing the characteristics of melange, consist of low-density, low-viscosity, highly sheared metasediments and/or serpentinite-rich matrix with relatively rigid blocks. The channel materials flow downwards and upwards, forming a kind of channel convection. Based on geophysical and geological observations on active oceanic subduction zones, combined with numerical simulations, the subduction channel model was initially set to shallow depths With the development of numerical simulation technology and fossil subduction zone investigations, the subduction channel model was extended to depths of 80–100 km to describe deeper geodynamic environments of oceanic subduction zones and explore the exhumation of high to ultrahigh pressure metamorphic rocks. It is also extended to continental subduction zones in order to explain the exhumation of metamorphic rocks in different grades as well as fluid activity and crust-mantle interaction during continental subduction. Although there are a series of differences in material composition and slab/mantle interface property between the upper and lower plates, continental subduction channels exhibit many similarities in structure and dynamics to oceanic subduction channels. Existing studies have provided a fundamental understanding of the structural and dynamic characteristics of subduction channels, but many problems still need to be solved and clarified. In particular, the fundamental characteristics of subduction channels obtained by numerical simulation need to be confirmed and modified through geological investigations of fossil subduction channels.