Cyclic Transmission Research Articles

Impacts of Drought on Photosynthesis in Major Food Crops and the Related Mechanisms of Plant Responses to Drought.

Drought stress is one of the most critical threats to crop productivity and global food security. This review addresses the multiple effects of drought on the process of photosynthesis in major food crops. Affecting both light-dependent and light-independent reactions, drought leads to severe damage to photosystems and blocks the electron transport chain. Plants face a CO2 shortage provoked by stomatal closure, which triggers photorespiration; not only does it reduce carbon fixation efficiency, but it also causes lower overall photosynthetic output. Drought-induced oxidative stress generates reactive oxygen species (ROS) that damage cellular structures, including chloroplasts, further impairing photosynthetic productivity. Plants have evolved a variety of adaptive strategies to alleviate these effects. Non-photochemical quenching (NPQ) mechanisms help dissipate excess light energy as heat, protecting the photosynthetic apparatus under drought conditions. Alternative electron pathways, such as cyclical electron transmission and chloroplast respiration, maintain energy balance and prevent over-reduction of the electron transport chain. Hormones, especially abscisic acid (ABA), ethylene, and cytokinin, modulate stomatal conductance, chlorophyll content, and osmotic adjustment, further increasing the tolerance to drought. Structural adjustments, such as leaf reordering and altered root architecture, also strengthen tolerance. Understanding these complex interactions and adaptive strategies is essential for developing drought-resistant crop varieties and ensuring agricultural sustainability.

Cyclic transmission window-based bandwidth allocation scheme for asynchronous time-sensitive industrial applications in TDM-PON

The industrial Internet has become an important application scenario for time-division multiplexing passive optical networks (TDM-PONs). Time-sensitive (TS) industrial applications, such as control-to-control communications, require a TDM-PON to have deterministic transmission capability. Traditional bandwidth allocation schemes are unable to fulfill this capability; thus we proposed a time-aware deterministic bandwidth allocation (TA-DetBA) scheme to guarantee deterministic delay and jitter in our previous work. TA-DetBA allocates appropriate transmission windows (TWs) to each TS industrial flow in a supercycle based on the flow’s arrival time, cycle, delay, and jitter requirements. However, “awaring” the arrival time of flow relies on precise time synchronization between the TDM-PON and industrial devices, which makes TA-DetBA unsuitable for those TS industrial applications that are asynchronous to the TDM-PON. In addition, the diversity of flow cycles may make the size of the supercycle and the number of allocated TWs large, thus increasing the complexity of the TW scheduling algorithm. To this end, we propose a cyclic TW-based deterministic bandwidth allocation (CTW-DetBA) scheme for asynchronous industrial applications. First, we design cyclic TWs with appropriate cycle and size for TS industrial flows, which not only improves the schedulability of TWs (i.e., the ratio of the number of successfully scheduled TWs to the total number of TWs) but also reduces the complexity of the algorithm. Then, we construct a TW scheduling model based on the satisfiability model theory to schedule the TWs in the PON upstream frame. Simulation results show that the CTW-DetBA guarantees the deterministic transmission of TS industrial flows that are asynchronous to the TDM-PON system. Compared with the fixed bandwidth allocation scheme, the average schedulability of the CTW-DetBA can be increased by up to 62.03%, and the average resource utilization efficiency can be increased by up to 20.4%.

Optimized planar printed UCA configurations for OAM waves and the associated OAM mode content at the receiver

SummaryUtilization of planar printed uniform circular antenna arrays (UCA) to generate the orbital angular momentum (OAM) carrying waves in the millimeter‐wave (mmWave) frequency band is advantageous from the viewpoints of easy signal modulation and mode reconfiguration, low cost, low profile, and straightforward integration with the existing broadband wireless infrastructure. The OAM mmWave UCA are highly promising as the enablers of very high transmission data rates required by hybrid 5G/6G optical and wireless communication systems by complementing and enhancing other technologies currently in use. Therefore, we here contribute a detailed electromagnetic analysis of important constraints of such antenna arrangements aimed at short‐range multimode OAM wave transmission. We investigate (i) the required antenna array dimensions and optimized UCA arrangements for a particular link range and (ii) the corresponding mode structure of OAM waves in the plane of receiving arrays. Four relatively simple antenna configurations operating in the 60‐GHz band are compared. Theoretical assumptions based on ideal OAM modes are critically assessed and, using state‐of‐the‐art numerical electromagnetic analysis, compared to realistically generated OAM waves. The proposed “cyclic transmission setup” resulted in much lower unwanted field components in the region of receiving arrays. RMS magnitudes of unwanted modes are on average about 64% of the received mode, in comparison with 80% (up to 94%) for sequential transmission. The observed mode impurities and mode mixing effects at the receiver indicate the need to dedicate more attention to the system‐level design, the development of efficient receiving arrays, the MIMO processing, and the stream separation.

CRC-Aided Sparse Regression Codes for Unsourced Random Access

This letter considers a coding scheme for unsourced random access (URA) based on sparse regression codes (SPARCs). In particular, an efficient concatenated coding scheme is proposed, which concatenates SPARCs and cyclic redundancy check-based block Markov superposition transmission (CRC-BMST) codes. A hybrid decoder consisting of a successive cancellation algorithm and a simplified approximated message passing (AMP) algorithm is presented for inner SPARCs, and an improved tree decoder is proposed for outer CRC-BMST codes by introducing a pruning technique. Simulation results show the proposed coding scheme outperforms the coded compressed sensing (CCS) scheme with lower computational complexity.

Sugar restriction and blood ingestion shape divergent immune defense trajectories in the mosquito Aedes aegypti

Immune defense is comprised of (1) resistance: the ability to reduce pathogen load, and (2) tolerance: the ability to limit the disease severity induced by a given pathogen load. The study of tolerance in the field of animal immunity is fairly nascent in comparison to resistance. Consequently, studies which examine immune defense comprehensively (i.e. considering both resistance and tolerance in conjunction) are uncommon, despite their exigency in achieving a thorough understanding of immune defense. Furthermore, understanding tolerance in arthropod disease vectors is uniquely relevant, as tolerance is essential to the cyclical transmission of pathogens by arthropods. Here, we tested the effect(s) of dietary sucrose concentration and blood ingestion on resistance and tolerance to Escherichia coli infection in the yellow fever mosquito Aedes aegypti. Resistance and tolerance were measured concurrently and at multiple timepoints. We found that mosquitoes from the restricted sugar treatment displayed enhanced resistance at all timepoints post-infection compared to those from the laboratory standard sugar treatment. Blood also improved resistance, but only early post-infection. While sucrose restriction had no effect on tolerance, we show that consuming blood prior to bacterial infection ameliorates a temporal decline in tolerance that mosquitoes experience when provided with only sugar meals. Taken together, our findings indicate that different dietary components can have unique and sometimes temporally dynamic impacts on resistance and tolerance.

Enhancing the thermal stability of S/Se based thermoelectric materials using self-generated oxide films

This study focuses on the thermal stability of Cu1.8S materials. During the ball milling process, metal powder is added to the milled Cu1.8S powder, and then the obtained powder is sintered using current assisted sintering to obtain dense blocks. The aim is to enable the added metal elements to spontaneously grow an oxide film on the surface of the material block at high temperature, achieving protection of the material matrix. The thermal stability of materials is evaluated by utilizing changes in room temperature phase composition before and after high-temperature heat treatment, changes in material electrical conductivity during high-temperature processes, and cyclic electrical transmission performance testing. By observing the surface oxide film state of the material after high-temperature treatment, the commonalities and differences in the effects of different element additions on the thermal stability of the material were analyzed. The effects of different metal elements on material hardness and electrical transmission performance were evaluated. It is found that adding metal powder can effectively improve the thermal stability of Cu1.8S, improve material hardness, and regulate the electrical transmission performance of the material. The characteristics of the oxide film formed by the spontaneous growth of metal elements and oxygen on the surface of the material substrate determine the effectiveness of the oxide film in protecting the material from high temperatures. The pure Cu1.8S bulk can only maintain stability at 300 oC, and the addition of Cr, Al, 316L, Fe, and Mn powder respectively increased the stable temperature of the material to 400, 400, 450, 450, 500 oC. Adding metal elements to the material matrix to grow an oxide film on the surface of the material to prevent high-temperature oxidation or decomposition is an effective way to improve the thermal stability of S/Se compounds.

Experimental study of intrinsic localized mode mobility in a cyclic, balanced, 1D nonlinear transmission line.

Mobile intrinsic localized modes (ILMs) in balanced nonlinear capacitive-inductive cyclic transmission lines are studied by experiment, using a spatiotemporal driver under damped steady-state conditions. Without nonlinear balance, the experimentally observed resonance between the traveling ILM and normal modes of the nonlinear transmission line generates lattice drag via the production of a lattice backwave. In our experimental study of a balanced running ILM in a steady state, it is observed that the fundamental resonance can be removed over extended, well-defined driving frequency intervals and strongly suppressed over the complete ILM driving frequency range. Because both of these nonlinear capacitive and inductive elements display hysteresis our observation demonstrates that the experimental system, which is only partially self-dual, is surprisingly tolerant, regarding the precision necessary to eliminate the ILM backwave. It appears that simply balancing the cell dual nonlinearities makes the ILM envelope shape essentially the same at the two locations in the cell, so that the effective lattice discreteness seen by the ILM nearly vanishes.

Vector competence of sterile male Glossina fuscipes fuscipes for Trypanosoma brucei brucei: implications for the implementation of the sterile insect technique in a sleeping sickness focus in Chad

BackgroundHuman African trypanosomiasis (HAT) is a neglected tropical disease caused by Trypanosoma brucei gambiense transmitted by tsetse flies in sub-Saharan West Africa. In southern Chad the most active and persistent focus is the Mandoul focus, with 98% of the reported human cases, and where African animal trypanosomosis (AAT) is also present. Recently, a control project to eliminate tsetse flies (Glossina fuscipes fuscipes) in this focus using the sterile insect technique (SIT) was initiated. However, the release of large numbers of sterile males of G. f. fuscipes might result in a potential temporary increase in transmission of trypanosomes since male tsetse flies are also able to transmit the parasite. The objective of this work was therefore to experimentally assess the vector competence of sterile males treated with isometamidium for Trypanosoma brucei brucei.MethodsAn experimental infection was set up in the laboratory, mimicking field conditions: the same tsetse species that is present in Mandoul was used. A T. b. brucei strain close to T. b. gambiense was used, and the ability of the sterile male tsetse flies fed on blood with and without a trypanocide to acquire and transmit trypanosomes was measured.ResultsOnly 2% of the experimentally infected flies developed an immature infection (midgut) while none of the flies developed a metacyclic infection of T. b. brucei in the salivary glands. We did not observe any effect of the trypanocide used (isometamidium chloride at 100 mg/l) on the development of infection in the flies.ConclusionsOur results indicate that sterile males of the tested strain of G. f. fuscipes were unable to cyclically transmit T. b. brucei and might even be refractory to the infection. The data of the research indicate that the risk of cyclical transmission of T. brucei by sterile male G. f. fuscipes of the strain colonized at IAEA for almost 40 years appears to be small.Graphical

Stability control of cyclic signal transmission in high power drive circuit

In order to reduce the influence of noise on the stability of cyclic signal transmission and improve the effect of signal control, a method to control the stability of cyclic signal transmission of high-power driving circuit is proposed. The main components of the driving circuit and the characteristics of its cyclic signal are analyzed. According to the analysis results, a cyclic signal transmission interference detection module is designed, and the source interference detection is realized by using this module; Considering the electromagnetic influence of the circulating signal and the power part, the optocoupler isolation method is used to isolate the circulating signal; On the basis of detecting and isolating the transmission interference of circulating signal, the primary pulse width modulation signal and the secondary fault feedback signal are modulated by a single pulse transformer to realize the bidirectional transmission design of circulating signal; The internal optimization design of the high-power drive circuit is carried out, the error correction of the signal transmission stability control is carried out by using the linearized small interference error compensation method, and the empirical mode decomposition method is applied to the cyclic signal analysis of the high-power drive circuit to solve the cross term interference problem in the cyclic signal analysis. Finally, the stability control of cyclic signal transmission is realized by using double quasi PR controller. The experimental results show that the signal transmission time of this method is short, the minimum value is less than 0.5 s, the signal transmission deviation is only 0.22, the transmission rate is high, the signal transmission deviation is small, and the signal waveform is stable, which fully shows that its control effect is good.

A general mathematical modeling and finite element analysis of a strain wave gear possessing a double-circular-arc-with-a-common-tangent profile

In this study, the characteristics of a strain wave gear (SWG) with a double-circular-arc with a common tangent (DCACT) profile were simulated using two-dimensional (2D) and three-dimensional (3D) finite element analysis (FEA). First, theoretically generated tooth profiles for the flexible spline (FS) and circular spline (CS) of an SWG were developed according to the theory of gearing. An automated mesh-generating computer program was developed in Visual C++ to establish 2D and 3D finite element models of the SWG based on its derived geometry. An FEA was then performed to explore the meshing characteristics, including the stress distribution, torsional angle, torsional stiffness, and number of engaged teeth, of the SWG. Continuous meshing of multiple tooth pairs between the FS and CS from the 2D FEA verified the conjugation of tooth profiles. The coning effect on the FS during assembly of the SWG was also predicted and discussed from the 3D FEA results. The 3D FEA produced more accurate and practical results than the 2D FEA did. Additionally, 3D FEAs of a modified (with longitudinal crowning) and unmodified (without longitudinal crowning) FS were performed and compared. Finally, a 3D FEA of a modified FS was successfully conducted to predict cyclic contact stress, root stress, and transmission error.

Asymmetric cyclic controlled quantum teleportation by using a quantum channel composed of six G states

In the existing research on cyclic teleportation protocols, it is generally discussed that the teleportation of single particle, two particle unknown quantum states with symmetrical structure or asymmetric special unknown quantum states (such as GHZ state) with three or four participants. In contrast, the scheme proposed in this paper has universality and stronger practicability. In this paper, we propose a novel scheme of asymmetric cyclic controlled teleportation. In our scheme, Alice can teleport an arbitrary single-qubit entangled state to Charlie, Charlie can teleport an arbitrary three-qubit entangled state to Bob and at the same time Bob can teleport an arbitrary two-qubit entangled state to Alice under the control of a controller David. It only needs Bell measurement and local unitary operation, and can realize three-party cyclic transmission with probability 1 by using a quantum channel composed of any six of the 16 G states.

A longitudinal two-year survey of the prevalence of trypanosomes in domestic cattle in Ghana by massively parallel sequencing of barcoded amplicons.

BackgroundAnimal African Trypanosomiasis (AAT) is one of the most economically important diseases affecting livestock productivity in sub-Saharan Africa. The disease is caused by a broad range of Trypanosoma spp., infecting both wild and domesticated animals through cyclical and mechanical transmission. This study aimed to characterize trypanosomes present in cattle at regular intervals over two years in an AAT endemic and a non-endemic region of Ghana.Methodology/Principal findingsGroups of cattle at Accra and Adidome were selected based on their geographical location, tsetse fly density, prevalence of trypanosomiasis and the breed of cattle available. Blood for DNA extraction was collected at approximately four to five-week intervals over a two-year period. Trypanosome DNA were detected by a sensitive nested PCR targeting the tubulin gene array and massively parallel sequencing of barcoded amplicons. Analysis of the data was a semi-quantitative estimation of infection levels using read counts obtained from the sequencing as a proxy for infection levels. Majority of the cattle were infected with multiple species most of the time [190/259 (73%) at Adidome and 191/324 (59%) at Accra], with T. vivax being the most abundant. The level of infection and in particular T. vivax, was higher in Adidome, the location with a high density of tsetse flies. The infection level varied over the time course, the timings of this variation were not consistent and in Adidome it appeared to be independent of prophylactic treatment for trypanosome infection. Effect of gender or breed on infection levels was insignificant.Conclusions/SignificanceMost cattle were infected with low levels of several trypanosome species at both study sites, with T. vivax being the most abundant. The measurements of infection over time provided insight to the importance of the approach in identifying cattle that could suppress trypanosome infection over an extended time and may serve as reservoir.

Experimental investigation of supertransmission for an intrinsic localized mode in a cyclic nonlinear transmission line.

In this experimental study of the nonlinear loss mechanism between traveling localized excitation and the underlying extended normal mode spectrum for a 1D lattice, three types of cyclic, electric, nonlinear transmission lines (NLTLs) are used. They are nonlinear capacitive, inductive, and capacitive+inductive NLTLs. To maintain a robust, steady-state traveling intrinsic localized mode (ILM), a traveling wave driver is used. The ILM loses energy because of a resonance between it and the extended NLTL modes. A wake field excitation is detected directly from ILM velocity experiments by the decrease in ILM speed and by the observation of the wake. Its properties are quantified via a two-dimensional Fourier map in the frequency-wavenumber domain, determined from the measured spatial-time voltage pattern. Simulations support and extend these experimental findings. We find for the capacitive+inductive NLTL configuration, when the two nonlinear terms are theoretically balanced, the wake excitation is calculated to become very small, giving rise to supertransmission over an extended driving frequency range.

Operation Optimization of Multiroute Cyclic Natural Gas Transmission Network under Different Objectives

Natural gas transmission networks (NGTNs) are the main facility connecting upstream gas sources and downstream consumers. For a cyclic NGTN with multiple gas transmission routes, different gas transportation schemes will affect not only the energy consumption of the system but also the pipeline transportation costs paid by consumers. In this paper, three operation optimization models are established to determine the optimal operating state of a multiroute cyclic NGTN under different scenarios. The three mathematical models correspond to three different objective functions: minimize the cost of compressor energy consumption, minimize the expense of pipeline transportation, and minimize the sum of the two expenses. The decision variables of the models include the pipeline flow rate, the number of operating compressors, and the outlet pressure of the compressors. In addition, a series of linear and nonlinear constraints of nodes, pipelines, and compressors is also proposed to guarantee the feasibility of solutions. The operation optimization problem is solved by the General Algebraic Modeling System (GAMS), and the effectiveness of this method is tested on a small double-route cyclic NGTN and a large three-route cyclic NGTN. The results show that the developed optimization model is able to find optimal solutions under different models. In the cyclic network, the difference in the flow distribution of gas transmission routes is the key factor affecting the optimization result. In addition, compared with the compressor energy consumption cost minimization objective, the pipeline transportation expense minimization objective can create greater economic benefits for consumers. In the two network cases, consumers can save 14.51 and 59.18×104 RMB. Finally, optimizing the two objectives at the same time makes it possible to achieve an effective balance between them.

Investigation on phase-modulation characteristics and transmission of the liquid crystal device under continuous-wave laser irradiation

Liquid crystal devices (LCDs) are widely used in several applications involving high-power lasers, such as laser processing, laser shaping, laser communication, laser radar and so on. Investigation on the performance of the LCDs working in high-power laser has always been of concern. In this study, a modified nearly common-path interferometry technique is proposed to investigate the phase modulation characteristics of the LCD irradiated by 1064 nm continuous-wave (CW) laser with Gaussian beam profile and an effective area of 0.1 cm2. In addition, the temperature rise of the LCD induced by laser irradiation was synchronously measured with an infrared thermal imager. A quantitative and dynamic investigation of the relation between the thermal effect caused by the laser and the phase-modulation variation is reported. Experimental results showed that the trend of temperature increase of the LCD was similar to that of phase shift variation. The theoretical phase shift calculated using the temperature-dependent LC refractive index coincided with the experimental results. This indicated that the refractive index change induced by temperature was the main reason for the phase-modulation variation of the LCD under laser irradiation. When the laser power was further increased, interference fringe distortion appeared, and morphological changes in the LC were observed. This implied that the laser-induced temperature rise had reached the clearing point of the LC and that the LCD was inactive. The temperature simulation along the laser incidence direction implied that, under the irradiation CW laser, indium tin oxide (ITO) layer absorbs laser energy, resulting in a temperature rise and a small temperature gradient between the ITO, polyimide (PI) and LC layers. The rising temperature is too low to induced damage of ITO layer and PI layer, but influences the refractive index of the LC. Compared with other layers of the LCD, the LC material will fail first when the irradiated laser power is further risen. The transmission variation of an LCD induced by laser irradiation was found. Possibly owing to the refractive index change of the LC as well as the multilayer film structure of the LCD, there seemed to be a cyclical transmission variation.

Evaluation of a Sexual Transmitted Infection Prevention Program Among University Students in Beira City Central Mozambique: A Study Protocol.

Background: Unhealthy sexual behaviors, such as unprotected sexual intercourse and lack of using screening services increase cyclical transmission of sexually transmitted infections including Human Immunodeficiency Virus (HIV), especially among young adults. Hence health promotion programs can contribute to reduce the consequences, by changing (determinants of) these behaviors. Such interventions need to embrace a comprehensive approach and apply theory-and evidence-based methods. This article describes the protocol for a process and effect evaluation study of a sexually transmitted infection prevention program among university students in Beira city, central Mozambique.Methods: The on-going program at Universidade Católica de Moçambique is described following the six steps of Intervention Mapping (IM), with a focus on the evaluation plan (i.e., the final step in IM). The details regarding previous steps in the protocol are briefly described as well, as they lay the foundation for the final step. The overall study will apply a hybrid type 1 approach by assessing the effectiveness of the intervention while gettering implementation. The process evaluation will apply qualitative and quantitative methods to gain insight in the context, reach, dose delivered, dose received and recruitment. Interviews with closed and open-ended questions will be conducted with program implementers and users. A quasi-experimental non-equivalent control group design is used to evaluate the effectiveness. A cohort of university students will be followed for 6 months. Self-administrated questionnaires will be used to collect data every 3 months.Discussion: A combination of process and effect evaluation is proposed. This is a useful and fruitful procedure, since concurrent process evaluation can allow researchers to better interpret findings from the effect evaluation and understand how the intervention might replicate in similar contexts. We decided to follow the IM approach since, it is a theory-and evidence-based, systematic and detailed guide regarding what to do at every steps. A quasi-experimental non-equivalent control group design was chosen to fit the context of the study and generate outcomes with high external validity.Study Registration: 004/CIBS/2020.

Genetic connectivity of trypanosomes between tsetse-infested and tsetse-free areas of Kenya.

The prevalence rates of trypanosomes, including those that require cyclical transmission by tsetse flies, are widely distributed in Africa. Trypanosoma brucei and Trypanosoma congolense are actively maintained in regions where there are no tsetse flies although at low frequencies. Whether this could be due to an independent evolutionary origin or multiple introduction of trypanosomes due to continuous movement of livestock between tsetse-free and -infested areas is not known. Thus, the aim of the study was to carry out microsatellite genotyping to explore intra-specific genetic diversity between T. (Trypanozoon), T. congolense and Trypanosoma vivax from the two regions: tsetse infested and tsetse free. Microsatellite genotyping showed geographical origin-based structuring among T. (Trypanozoon) isolates. There was a clear separation between isolates from the two regions signalling the potential of microsatellite markers as diagnostic markers for T. brucei and Trypanosoma evansi isolates. Trypanosoma vivax isolates also clustered largely based on the sampling location with a significant differentiation between the two locations. However, our results revealed that T. congolense isolates from Northern Kenya are not genetically separated from those from Coastal Kenya. Therefore, these isolates are likely introduced in the region through animal movement. Our results demonstrate the occurrence of both genetic connectivity as well as independent evolutionary origin, depending on the trypanosome species between the two ecologies.

Epidemiology of Trypanosomiasis in Wildlife-Implications for Humans at the Wildlife Interface in Africa.

While both human and animal trypanosomiasis continue to present as major human and animal public health constraints globally, detailed analyses of trypanosome wildlife reservoir hosts remain sparse. African animal trypanosomiasis (AAT) affects both livestock and wildlife carrying a significant risk of spillover and cross-transmission of species and strains between populations. Increased human activity together with pressure on land resources is increasing wildlife–livestock–human infections. Increasing proximity between human settlements and grazing lands to wildlife reserves and game parks only serves to exacerbate zoonotic risk. Communities living and maintaining livestock on the fringes of wildlife-rich ecosystems require to have in place methods of vector control for prevention of AAT transmission and for the treatment of their livestock. Major Trypanosoma spp. include Trypanosoma brucei rhodesiense, Trypanosoma brucei gambiense, and Trypanosoma cruzi, pathogenic for humans, and Trypanosoma vivax, Trypanosoma congolense, Trypanosoma evansi, Trypanosoma brucei brucei, Trypanosoma dionisii, Trypanosoma thomasbancrofti, Trypanosma elephantis, Trypanosoma vegrandis, Trypanosoma copemani, Trypanosoma irwini, Trypanosoma copemani, Trypanosoma gilletti, Trypanosoma theileri, Trypanosoma godfreyi, Trypansoma simiae, and Trypanosoma (Megatrypanum) pestanai. Wildlife hosts for the trypansomatidae include subfamilies of Bovinae, Suidae, Pantherinae, Equidae, Alcephinae, Cercopithecinae, Crocodilinae, Pteropodidae, Peramelidae, Sigmodontidae, and Meliphagidae. Wildlife species are generally considered tolerant to trypanosome infection following centuries of coexistence of vectors and wildlife hosts. Tolerance is influenced by age, sex, species, and physiological condition and parasite challenge. Cyclic transmission through Glossina species occurs for T. congolense, T. simiae, T. vivax, T. brucei, and T. b. rhodesiense, T. b. gambiense, and within Reduviid bugs for T. cruzi. T. evansi is mechanically transmitted, and T. vixax is also commonly transmitted by biting flies including tsetse. Wildlife animal species serve as long-term reservoirs of infection, but the delicate acquired balance between trypanotolerance and trypanosome challenge can be disrupted by an increase in challenge and/or the introduction of new more virulent species into the ecosystem. There is a need to protect wildlife, animal, and human populations from the infectious consequences of encroachment to preserve and protect these populations. In this review, we explore the ecology and epidemiology of Trypanosoma spp. in wildlife.

Ecoepidemiology and Potential Transmission of Vibrio cholerae among Different Environmental Niches: An Upcoming Threat in Egypt.

Cholera is a negative public health event caused by Vibrio cholerae. Although V. cholerae is abundant in natural environments, its pattern and transmission between different niches remain puzzling and interrelated. Our study aimed to investigate the occurrence of nonpathogenic V. cholerae in the natural environment during endemicity periods. It also aimed to highlight the role of molecular ecoepidemiology in mapping the routes of spread, transmission, and prevention of possible future cholera outbreaks. V. cholerae was detected in different aquatic environments, waterfowl, and poultry farms located along the length of the Nile River in Giza, Cairo, and Delta provinces, Egypt. After polymerase chain reaction amplification of the specific target outer membrane gene (Omp W) of suspected isolates, we performed sequence analysis, eventually using phylogenetic tree analysis to illustrate the possible epidemiological relationships between different sequences. Data revealed a significant variation in the physicochemical conditions of the examined Nile districts related to temporal, spatial, and anthropogenic activities. Moreover, data showed an evident association between V. cholerae and the clinically diseased Synodontis schall fish. We found that the environmental distress triggered by the salinity shift and elevated temperature in the Middle Delta of the Nile River affects the pathogenesis of V. cholerae, in addition to the characteristics of fish host inhabiting the Rosetta Branch at Kafr El-Zayat, El-Gharbia province, Egypt. In addition, we noted a significant relationship between V. cholerae and poultry sources that feed on the Nile dikes close to the examined districts. Sequence analysis revealed clustering of the waterfowl and broiler chicken isolates with human and aquatic isolated sequences retrieved from the GenBank databases. From the obtained data, we hypothesized that waterfowl act as a potential vector for the intermediate transmission of cholera. Therefore, continuous monitoring of Nile water quality and mitigation of Nile River pollution, in addition to following good managemental practices (GMPs), general hygienic guidelines, and biosecurity in the field of animal production and industry, might be the way to break this cyclic transmission between human, aquatic, and animal sectors.

Mature viral cathepsin is required for release of viral occlusion bodies from Autographa californica multiple nucleopolyhedrovirus-infected cells

Baculovirus-infected larvae release progeny viral occlusion bodies (OBs) to enable cyclical virus transmission to new hosts. The alphabaculovirus chitinase and cathepsin enzymes cause terminal liquefaction of host insect cadavers, aiding OB dispersal. The mechanism of cell lysis required to release the OBs is unclear but here we show Autographa californica multiple nucleopolyhedrovirus cathepsin protease activity is required for efficient release of the host tissue-degrading chitinase and cathepsin enzymes and critical for release of progeny OBs from virus-infected cells. Comparisons between viruses containing or lacking cathepsin indicate that cathepsin was necessary for OB release into cultured cell media or hemolymph of insects. In addition, pharmacological inhibition of cysteine protease activity in cells during infection blocked maturation of active cathepsin and OB release from infected cells. Together, these results suggest an important link between baculovirus-induced cell lysis, the concomitant maturation of cathepsin, and cellular release of chitinase, cathepsin and progeny OBs from cells.