High Parasite Research Articles

Population Genetic Structure of Anisakis simplex Infecting the European Hake from North East Atlantic Fishing Grounds.

The European hake, one of the most commercially valuable species in ICES fishing areas, is considered an important neglected source of zoonotic risk by nematode parasites belonging to the genus Anisakis. Merluccius merluccius is, by far, the most important host of Anisakis spp. at the European fishing grounds, in terms of demographic infection values, and carries the highest parasite burden. These high parasite population densities within an individual fish host offer a chance to explore new sources of variations for the genetic structure of Anisakis spp. populations. A total of 873 Anisakis spp. third-stage larvae, originally sampled from viscera and muscular sections of hake collected at ten fishing grounds, were primarily identified using ITS rDNA region as molecular marker. After that, we used mtDNA cox2 gene to reveal the high haplotype diversity and the lack of genetic structure for A. simplex. Dominant haplotypes were shared among the different fishing areas and fish sections analyzed. Results indicate a clear connection of A. simplex from European hake along the Northern North Sea to the Portuguese coast, constituting a single genetic population but revealing a certain level of genetic sub-structuring on the Northwest coast of Scotland. This study also provides useful information to advance the understanding of parasite speciation to different fish host tissues or microenvironments.

A Study of Malaria in West Bengal

Background: Malaria still occurs in West Bengal which is one of the states in the eastern part of India. Materials and Methods: The study design included an analysis of the 2017 and 2018 annual reports of the National Centre for Vector Borne Disease Control (NCVBDC). Results: The district of Kolkata had a high Annual Parasite Incidence (API) of Malaria of 3.72 during 2017 which decreased to 3.12 in 2018. Conclusion: If interventions such as the treatment of asymptomatic carriers take place, it is expected that the API will come down sooner in Kolkata district and in the rest of the state too.

Effects of nest concealment on nest predation and cowbird parasitism, flight initiation distance and female stress levels in the Wood Thrush

Temperate zone songbirds in North America can experience high levels of nest predation and Brown-headed Cowbird (<em>Molothrus ater</em>) parasitism, which may contribute to population declines, and an important question is whether nesting females can mitigate these threats through greater nest concealment. However, there is little known about the pros and cons of nest concealment to the incubating female, and whether concealment influences female corticosterone levels or nest escape behavior to potentially reduce risk of predation on females. This study investigates whether nest concealment resulted in reduced risk of nest predation and Brown-headed Cowbird parasitism in the Wood Thrush (<em>Hylocichla mustelina</em>), a forest bird that is declining across most of its range. We monitored nests (n = 186) in a highly fragmented forest landscape in southwestern Ontario, Canada and found high nest predation (53.2%) and moderate cowbird parasitism (25.3%). Overall nest concealment, nest height, and forest fragment size were not good predictors of daily nest survival or cowbird parasitism, but greater nest concealment one meter above the nest strongly reduced nest predation risk. We speculate that because most Wood Thrush nests are relatively low (< 2.5 m above ground), above-nest concealment may be effective against detection by avian nest predators. Overall nest concealment was not negatively correlated with flight initiation distance (FID) or positively related to baseline corticosterone level. This suggests that high nest concealment does not increase stress or personal risk to incubating females; however, nest concealment manipulations are needed to further explore whether any such trade-offs exist.

Parasitismo em local incomum de Dermacentor nitens (Acari: Ixodidae) em um cavalo

ABSTRACT: Dermacentor nitens Neumann is the most common tick species infesting horses in the main Brazilian biomes. It has a predilection to attach to horse the ears, the nasal diverticulum, perineal and perianal regions. The infestations can generate severe damage in the ears, anemia, and the tick also acts as vector of Babesia caballi (Nuttall and Strickland), the causative agent of equine babesiosis. Our study describes unusual parasitism site of D. nitens on a female cross breed horse, approximately ten years old that presented high parasitism by ticks on the perineal and perianal region, ears, and the left eye orbit region, where an enucleation process had been performed a few years earlier. To our knowledge this is the first report of D. nitens parasitism on a formerly enucleated eye orbit.

The Association between CRP Levels with Comorbidities, Species, and Complications of Severe Malaria

Background: Malaria remains a leading cause of mortality in sub-Saharan Africa (including Sudan). C-reactive protein (CRP) is useful as a marker of severity in malaria. African studies have shown that serum CRP levels correlate with parasite burden and complications in malaria, especially falciparum. However, there are no data on CRP levels in Sudanese malaria patients. This study aims to evaluate the association between CRP levels with comorbidities, species, and complications of severe malaria Subjects and Methods: A cross-sectional study enrolled 65 severe malaria patients at Khartoum state hospitals during the period from April to June2021. Manifestations of severe malaria were defined according to WHO criteria. Data regarding demographics, presenting symptoms &amp; signs, laboratory investigations, complications, length of hospital stay and outcomes were collected. CRP was classified as elevated when the measured level was &gt;10 mg/l. Results: Among 65 patients, 33(50.8%) were females and 32(49.2%) were males, and mean age was 48±21 years. The main manifestation of severe malaria diagnosis criteria was anemia in 26(40%) patients. Most of the patients had density 1+ (n=53; 81.5%) and were infected by P. falciparum (n=61; 93.8%). The overall case fatality rate for malaria was 8% (n=15 patients). The mean of CRP was 72±57 mg/L and 84% (n=55) of patients had elevated levels above 10 mg/L (ranged from 10-100 mg/L in 52%, and above 100 mg/L in 32%). The elevated CRP levels were significantly DM (P= 0.048), high malaria parasite density in blood film (P= 0.001), P. falciparum (P= 0.33), presence of complications (P= 0.001) and death (P= 0.003) Conclusion: Elevated CRP levels were found in a considerable proportion of severe malaria patients. CRP is an effective biomarker in assessing malaria severity and poor prognosis in term of complications development and mortality.

Biology of Brachymeria kamijoi Habu (Hymenoptera: Chalcididae), a pupal parasitoid of the coconut black-headed caterpillar, Opisina arenosella Walker (Lepidoptera: Xyloryctidae)

The coconut black-headed caterpillar, Opisina arenosella Walker (Lepidoptera: Xyloryctidae) has been one of the most serious defoliators of coconut plants in Vietnam. Brachymeria kamijoi Habu (Hymenoptera: Chalcididae) is a pupal parasitoid of O. arenosella with high percent parasitism and abundance in the coconut fields and appears to be a good biological control agent against the coconut black-headed caterpillar in Vietnam. This study was carried out at Entomology Laboratory, Faculty of Agronomy, Nong Lam University, Vietnam during 2020 – 2021 to determine some biological characteristics of B. kamijoi on O. arenosella at a constant temperature of 28 oC and a photoperiod of 12L: 8D. Total developmental time from egg to adult emergence was 13.8 days. The females laid a mean of 98.1 eggs during an average lifespan of 30.7 days. Fecundity peaked at a large range of age 7 -29 days. The results would contribute to the knowledge of the biology of B. kamijoi to optimize a mass-rearing system for a biological control programme against O. arenosella.

Semi-supervised graph learning framework for apicomplexan parasite classification

Apicomplexan parasites cause diseases including malaria, toxoplasmosis, and babesiosis, affecting large parts of the world and hampering economic development to a considerable severity. Early recognition of pathogenic parasites can effectively constrain the spread of these infectious diseases. Recently, deep-learning-based computer-aided parasite recognition systems provide many practical tools for automated apicomplexan parasite recognition. However, existing research works are limited by the complicated and expensive manual annotating workload in supervised deep learning methods, which require many experts’ manually annotated samples. Moreover, they also ignore the significance of correlations among different parasite cells, which retain helpful information for identification. Therefore, this paper is the first to employ a semi-supervised learning strategy to reduce the manual labeling workload and introduce a hybrid graph learning algorithm into parasite recognition. Our approach has a superior parasite recognition capability with semi-supervised techniques and the graph-based model. Specifically, this research proposes a Semi-Supervised Graph Learning (SSGL) framework, composing CNN (Convolutional Neural Networks) feature embedding, learnable graph building, and graph feature learning components. To verify the performance of the SSGL model, the paper applies multiple evaluation indicators to appraise our model, and the approach can achieve high accuracy of 91.75%, AUC of 91.83%, the sensitivity of 91.75% and specificity of 97.25% with only a small amount of labeled data (20%). In conclusion, SSGL model provides high parasite recognition capability with minimal labels, greatly reduces the workload of relevant experts, and promotes the popularization of computer-aided parasite diagnosis tools.

Malaria Transmission and Asymptomatic Malaria during Rainy Season among Nomads, North-eastern Nigeria

Aim: To determine the point prevalence of malaria infection and asymptomatic malaria during rainy season among some nomads of North Eastern Nigeria.&#x0D; Study Design: A cross sectional observational study.&#x0D; Place and Duration of Study: The study was conducted across 11 randomly selected nomads’ camps around the Rivers Gongola and Benue basins spread over 3 Local Government Areas of Southern Adamawa State of North Eastern Nigeria. Data was collected during rainy season between July and September, 2016.&#x0D; Methodology: Fifty-five randomly selected households (5 from each camp) were covered in the survey. One hundred and ninety two (192) consenting participants aged between 1 and 79 years (inclusive) were involved in the survey. Structured questionnaires were administered (care givers consented and responded on behalf of children) and blood samples collected. Blood samples were examined for malaria parasite using a microscopes and results of both survey and microscopy analysed.&#x0D; Results: Overall malaria parasite prevalence was 87.5% and mean parasite density was 36,168 parasites per μl of blood. Thirty five (18.2%) of participant were of low parasite density, 35.5% were of moderate parasite density while 32.8% were of high parasite density. More than half (53%) of the malaria positive participants did not experience febrile symptoms within one month prior to the survey and were therefore asymptomatic. Tendency of manifestation of symptoms significantly increased with parasite density and decreased with age. The use of preventive measures against mosquito bite was 7.7% and only 16.1% of participants used antimalarial medicines or sought medical attention during their most recent fever episode.&#x0D; Conclusion: The high prevalence of asymptomatic carriers with high parasite densities and abysmally low usage of preventive and curative measures among the study population represents an ideal condition for effective malaria transmission which is unlikely to abate unless control measures are intensified.

A scientometric study on prevalence of gastrointestinal parasites in pigs (Sus scrofa) of India

In this study, prevalence of the gastrointestinal (GI) parasites in pigs from India was estimated by employing scientometrics. The prevalence studies on the GI parasites of pigs (n=21) were acquired from online and offline databases (timeline: 2010-2021) and meta-analysis was performed using meta package in R-software. The prevalence of GI parasites in pigs was 54% (95% level: CI 39-69%, PI 5-96% of 8,921 samples tested) in India. A higherprevalence of 81% was reported in 2010 than the recent years (2016-21). The highest prevalence in South zone (78%), and least in West zone (35%) was observed. The prevalence of GI parasites was highest in Tamil Nadu (96%) and lowest in Maharashtra (28%). The higher prevalence was observed in protozoa (30%) than other parasite classes and lower in cestodes (4%) in pigs. More number of studies have been reported on nematode parasites indicating its importance in pigs. A higher prevalence was observed in the studies conducted on samples (84%) collected from slaughterhouse than the faecal samples (46%) in pigs. Among the parasite species, coccidia (29%) were most commonly reported whereas Globocephalus urosubulatus (0.7%) was observed sporadically low. Amongst nematodes and trematodes, a higher prevalence in Ascaris spp. (27%) and Amphistomes (12%), correspondingly was observed. The high GI parasites prevalence zones, states, parasite classes, sample types and parasite species recognized will assist the stakeholders and decision makers, in control and preventive approaches. Further, this study provides the baseline information on GI parasites prevalence in pigs of India for devising effective deworming strategies which ultimately lead to beneficial piggery in India.

A spatiotemporally resolved single-cell atlas of the Plasmodium liver stage.

Malaria infection involves an obligatory, yet clinically silent liver stage1,2. Hepatocytes operate in repeating units termed lobules, exhibiting heterogeneous gene expression patterns along the lobule axis3, but the effects of hepatocyte zonation on parasite development at the molecular level remain unknown. Here we combine single-cell RNA sequencing4 and single-molecule transcript imaging5 to characterize the host and parasite temporal expression programmes in a zonally controlled manner for the rodent malaria parasite Plasmodium berghei ANKA. We identify differences in parasite gene expression in distinct zones, including potentially co-adaptive programmes related to iron and fatty acid metabolism. We find that parasites develop more rapidly in the pericentral lobule zones and identify a subpopulation of periportally biased hepatocytes that harbour abortive infections, reduced levels of Plasmodium transcripts and parasitophorous vacuole breakdown. These 'abortive hepatocytes', which appear predominantly with high parasite inoculum, upregulate immune recruitment and key signalling programmes. Our study provides a resource for understanding the liver stage of Plasmodium infection at high spatial resolution and highlights the heterogeneous behaviour of both the parasite and the host hepatocyte.

Abstract 15242: Donor-Derived Chagas Disease Masquerading as Acute Heart Transplant Rejection

Introduction: Although Chagas disease affects over 300,000 residents in the US, donor-derived Trypanosoma cruzi transmission is an uncommon complication after heart transplantation. We present a case of post-transplant Chagas cardiomyopathy. Results: A 68 year old male with history of heart failure with reduced ejection fraction secondary to ischemic cardiomyopathy, status post HeartMate III and subsequent orthotopic heart transplantation from a Hispanic donor, initially presented four months after transplant for routine right heart catheterization. Endomyocardial biopsy showed grade 2R acute cellular rejection. Patient was treated with IV steroids and discharged. One month later, he presented with one week of fevers, malaise, non-tender erythematous patches on his upper body and hemorrhagic bullae on his buccal mucosa. Initial workup was notable for pancytopenia with WBC 1.3 x10e9/L, hemoglobin 10.3g/dL, and platelets 77 x10e9/L, troponin 3.47 ng/mL, NT-proBNP 11,331 pg/mL, and new right bundle branch block on electrocardiogram. Cardiac MRI showed extensive multifocal late gadolinium enhancement and pericardial exudates, suggestive of atypical infection. Despite treatment with Filgrastim and IVIG, the patient progressed to cardiogenic shock complicated by complete heart block requiring transvenous pacing, and ventricular tachycardia. On hospital day 5, a peripheral smear confirmed Trypanosoma cruzi with high parasite burden and amastigotes were visualized on a shave biopsy of his rash. Patient was initiated on Benznidazole. He was treated in the intensive care unit, where his course was further complicated by recurrent VT, for which he received an implantable cardiac defibrillator, and renal failure requiring hemodialysis. Conclusions: We present a case of suspected donor-derived Chagas Disease. In retrospect, this patient’s initial episode of acute rejection was most likely due to Chagas Disease. Due to increasing globalization of endemic diseases and life-threatening complications associated with this disease, a high index of suspicion is required to diagnose and treat T. cruzi after heart transplantation in the setting of non-specific symptoms.

Detection of intestinal parasites in human faecal samples using dissolved air flotation.

Ova and parasite (O&P) examination is recommended for the laboratory diagnosis of agents causing parasitic infections; however, this exam requires scientific and technological improvements to enhance its diagnostic validity. Dissolved air flotation (DAF) is an efficient technical principle separating suspended solids in a liquid medium. We aimed to develop and validate a new procedure for intestinal parasite detection with DAF. In this study, we collected samples from 500 volunteers, screened them by direct examination, and transferred the material to tubes using the Three Faecal Test (TF-Test) for triplicate DAF tests. We evaluated physical-chemical parameters and DAF prototype components through quantifying parasites recovered from floated and non-floated regions of the flotation column. The DAF operation protocol was validated with the gold standard results. The 10% saturated volume proportion and cationic surfactant showed regularity and high parasite recovery (80%). Modifications of the needle device did not influence parasite recovery (p> 0.05). Sensitivity, specificity, accuracy and kappa agreement obtained with the DAF protocol were 91%, 100%, 93% and substantial (k= 0.64), respectively. The DAF principle could be used to process faecal samples in routine laboratory exams, enabling intestinal parasite detection.

Global genomic methylation related to the degree of parasitism in cattle

The objective of the present study was to characterize a herd of 72 ½ Angus × ½ Nellore heifers, identify the resistant, resilient and susceptible animals to parasites, relate the overall DNA methylation of these animals with the degree of parasitism, evaluated by the egg count per gram of feces (EPG), Haematobia irritans count (horn fly) and Rhipicephalus microplus count (bovine tick). The experiment was carried out in a completely randomized design, containing 72 treatments, with each animal considered a treatment, and 11 repetitions, with each collection within a year considered a repetition. The data obtained from the counts of the evaluated parasites were subjected to statistical analysis using the SISVAR program, to classify heifers according to the degree of parasitism in low (resistant), intermediary (resilient) and high (susceptible) parasite load for infection by nematodes, infestation by ticks and flies. Addition the animals in these three groups, by hierarchical grouping using the GENES program, heifers were classified as to the degree of parasitism by the three parasites along with the DNA methylation content of the animals in each group. A negative relationship was observed between resistance and methylated DNA content in both classifications, with the resistant, resilient, and susceptible animals showing the highest, intermediate, and lowest methylated DNA quantifications, respectively. Thus, the methodologies used herein enabled the classification of 72 heifers according to the degree of collective infection by gastrointestinal nematodes and infestation by ticks and horn flies, thereby establishing a link between the degree of parasitic resistance in cattle and the global methylated DNA quantification.

Annual and Seasonal Changes in Parasitism Rates by Hadronotus Pennsylvanicus (Hymenoptera: Scelionidae) on the Squash Bug Anasa Tristis (Hemiptera: Coreidae) in Squash Fields: Implications for Augmentative Releases.

This study evaluated parasitism rates by Hadronotus pennsylvanicus (Ashmead) (Hymenoptera: Scelionidae) on the squash bug Anasa tristis DeGeer (Hemiptera: Coreidae) over a six-year period in squash fields in Maryland. From 2016-2021, 2226 wild squash bug egg masses were collected, 2180 (98.0%) A. tristis egg masses and 46 (2.0%) A. armigera egg masses. The mean (±SE) parasitism rate was 10.9 ± 0.16%. Yearly parasitism rates were significantly different with rates in 2017 and 2018 that were significantly lower than in 2019, 2020, and 2021. The significant difference in parasitism rates based on planting date was primarily due to the high parasitism rate observed in 2021. These results suggest that the use of augmentative releases early in the season could result in effective control by increasing parasitism earlier in the season and by causing the parasitism rate in the field to peak at a higher number late in the season.

Polarisation of human macrophages towards an M1 subtype triggered by an atypical Brazilian strain of Toxoplasma gondii results in a reduction in parasite burden.

Toxoplasma gondii Nicolle et Manceaux, 1909, the etiologic agent of toxoplasmosis, was considered a clonal population with three distinct genetic lineages (I, II and III); however, sequence analysis of different strains has revealed distinct atypical genotypes. Macrophages are essential for immunity against toxoplasmosis and differential cell regulation may affect the course of the disease. In this context, our study aims to investigate the infection by TgChBrUD2, a highly virulent atypical Brazilian strain of T. gondii, on the activation and polarisation of human macrophages. Human macrophage-like cells obtained from THP-1 cells were infected with TgChBrUD2, RH or ME49 strains of T. gondii to evaluate the impact of parasite infection on macrophage polarisation. Our results indicate that the TgChBrUD2 and ME49 strains of T. gondii induced a classic activation of human macrophages, which was confirmed by the high rate of spindle-shaped macrophages, low amount of urea and increase in the levels of nitrite, as well as the down-regulation of M2-markers. In contrast, RH strain promoted an alternative activation of macrophages. The polarisation of human macrophages towards an M1 subtype mediated by TgChBrUD2 and ME49 strains resulted in a low parasite burden, with high levels of IL-6 and MIF. Finally, the M2 subtype triggered by the RH strain culminated in a lower intracellular proliferation index. We concluded that the atypical (TgChBrUD2) and clonal (ME49) strains are able to elicit an M1 subtype, which results in parasitism control, partially explained by the high levels of IL-6 and MIF produced during the infection by these genotypes. In contrast, the clonal (RH) strain promoted a macrophage polarisation towards an M2 subtype, marked by a high parasite burden, with a weak modulation of pro-inflammatory cytokines. Thus, atypical strains can present different mechanisms of pathogenicity and transmissibility compared to clonal strains, as well as they can use distinct strategies to evade the host's immune response and ensure their survival.

Impedance-Matching Shunt: Current Sensor With Ultrahigh Bandwidth and Extremely Low Parasitics for Wide-Bandgap Device

The current shunt with high bandwidth and low parasitics is critically needed to satisfy the soaring current slew rate of the wide-bandgap (WBG) device. However, the existing lumped parameter model is inappropriate to model and design the next-generation ultrahigh bandwidth current shunt, leading to the unclear bandwidth limitation, inextricable invasive effect, and lacked design guidance. In this letter, by introducing the transmission line theory, it is revealed that, due to the impedance mismatch, the strong signal reflection inside the current shunt results in the high-frequency parasitic inductance, which severely deteriorates its bandwidth. On this basis, the concept of the impedance-matching shunt (IM-shunt) is then proposed to derive the mathematical model-guided design methodology for the high-performance current shunt. With the aid of the proposed concept, the current shunt with > 3 GHz bandwidth and < 0.1 nH parasitics is developed. The comparative experiments further ensure the accurate and nonintrusive characterization of the switching trajectories for the WBG application.

Troubled waters: Water availability drives human-baboon encounters in a protected, semi-arid landscape

Most animal habitats are affected by humans. While some species tolerate and even benefit from these changes, others suffer. Understanding when and how human-altered landscapes affect animal behavior, health, reproduction, and survival is essential to species management in a human-dominated world. Here we use 27 years of data on human-baboon encounters in a protected, semi-arid ecosystem in Kenya to: (i) identify spatial, environmental, and group-level predictors of baboon encounters with pastoralists; (ii) test whether human-built water sources alter baboon ranging patterns; and (iii) test if human encounters are linked to baboon survival, reproduction, and health. We find that the primary driver of human-baboon encounters is water availability. During dry periods, pastoralists migrate into baboon rangelands, leading to frequent human-baboon encounters, especially near water wells. Further, the baboons shift their ranges to encompass newly built wells and move away from abandoned, dried-up wells. Since 2006, a third of adult baboon deaths were linked to violent encounters with humans or their dogs. Human encounters were also linked to high infant mortality and parasite diversity in females (but this effect could not be disentangled from seasonal confounds). For wild baboons, life in protected, pastoralist conservancies presents a double-edged sword: human-built wells enable the baboons to access water during dry periods, but these wells lead to encounters with humans, which have become a common source of baboon mortality. Together, our results serve as a comprehensive case study of anthropogenic effects on wild primates, highlighting the complex interactions between humans and wildlife in protected areas.

Systematic Review and Meta-Analysis on Human African Trypanocide Resistance.

Background Human African trypanocide resistance (HATr) is a challenge for the eradication of Human African Trypansomiaisis (HAT) following the widespread emergence of increased monotherapy drug treatment failures against Trypanosoma brucei gambiense and T. b. rhodesiense that are associated with changes in pathogen receptors. Methods: Electronic searches of 12 databases and 3 Google search websites for human African trypanocide resistance were performed using a keyword search criterion applied to both laboratory and clinical studies. Fifty-one publications were identified and included in this study using the PRISMA checklist. Data were analyzed using RevMan and random effect sizes were computed for the statistics at the 95% confidence interval. Results: Pentamidine/melarsoprol/nifurtimox cross-resistance is associated with loss of the T. brucei adenosine transporter 1/purine 2 gene (TbAT1/P2), aquaglyceroporins (TbAQP) 2 and 3, followed by the high affinity pentamidine melarsoprol transporter (HAPT) 1. In addition, the loss of the amino acid transporter (AAT) 6 is associated with eflornithine resistance. Nifurtimox/eflornithine combination therapy resistance is associated with AAT6 and nitroreductase loss, and high resistance and parasite regrowth is responsible for treatment relapse. In clinical studies, the TbAT1 proportion of total random effects was 68% (95% CI: 38.0–91.6); I2 = 96.99% (95% CI: 94.6–98.3). Treatment failure rates were highest with melarsoprol followed by eflornithine at 41.49% (95% CI: 24.94–59.09) and 6.56% (3.06–11.25) respectively. HATr-resistant phenotypes used in most laboratory experiments demonstrated significantly higher pentamidine resistance than other trypanocides. Conclusion: The emergence of drug resistance across the spectrum of trypanocidal agents that are used to treat HAT is a major threat to the global WHO target to eliminate HAT by 2030. T. brucei strains were largely resistant to diamidines and the use of high trypanocide concentrations in clinical studies have proved fatal in humans. Studies to develop novel chemotherapeutical agents and identify alternative protein targets could help to reduce the emergence and spread of HATr.

Integrated DC - DC converter design methodology for design cycle speed up

A novel design methodology, enabling extreme design cycle time speed up of DC - DC power converters, is developed. The concept is based on providing high accuracy post-layout RC parasitics aware results, by replacing complicated large RC netlists with small signal approximation models. Scattering parameters analysis is adopted for “on the fly” performance simulation of the power MOSFET switches' routings, which act as large passive linear networks. The RC parasitics aware back end of line (BEOL) S-parameter model is extracted and seamlessly integrated into the schematic testbench, considering the actual circuit as a black box and therefore actively cutting down the design's netlist size to minimum values. Thus, the DC – DC converter performance degradation, that previously could not be simulated, now is accurately predicted and evaluated while the respective simulation time and the number of design iterations needed from layout (physical design) to the schematic and vice versa, are minimized. The proposed methodology is validated using an Integrated Pulse Width Modulation controlled DC - DC converter product vehicle, for light energy harvesting applications, designed, simulated and fabricated in a 0.18 μm CMOS standard process. Experimental results confirm the accuracy and design cycle speed up effectiveness of the proposed novel IC power converter design methodology.

Interactions between the Entomopathogenic Fungus Metarhizium anisopliae ICIPE 20 and the Endoparasitoid Dolichogenidea gelechiidivoris, and Implications for Combined Biocontrol of Tuta absoluta.

Simple SummaryThe theory of beneficial species association in a cropping system can sustain ecosystem services and reduce pest pression under economic injury levels. For the control of the invasive pest, Tuta absoluta we assessed the susceptibility of Dolichogenidea gelechiidivoris to Metarhizium anisopliae ICIPE 20 through adult parasitoid and parasitised larval infection; furthermore, we evaluated the preference and performance of sprayed and non-sprayed host plants. We concluded an additive effect for Tuta absoluta control by the two biocontrol technologies even though the entomopathogenic fungus reduces the fitness of the parasitoid, such as adult longevity and its performance, and parasitised larval emergence.The Integrated Pest Management (IPM) approach have been widely promoted and used for the management of native and invasive pests, while the use of various components of the IPM can have a synergetic, additive, or antagonistic effect on each other; this study evaluated the susceptibility of Dolichogenidea gelechiidivoris (Marsh) (Hymenoptera: Braconidae), to the Metarhizium anisopliae (Metschnikoff) ICIPE 20 through direct and indirect infection approaches. The effect of fungus on parasitoid longevity, survival of parasitized-larvae, preference of the parasitoid to fungal treated and untreated larvae, and percent parasitism of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) under different infection scenarios were assessed. The direct application of dry conidia to the parasitoid prior to exposure to the host, reduced D. gelechiidivoris longevity, though the infected female wasps still yielded high parasitism (over 70%). Infecting the parasitized larvae at different ages led to a respective reduction of parasitoid emergence by 35% and 23% for infection at 1 and 5 days post-parasitisation. Exposure of healthy-D. gelechiidivoris adults to a plant-sprayed with fungus did not affect their longevity, and no discriminatory host selection was observed. The highest mortality (~80%) of T. absoluta was achieved when D. gelechiidivoris and M. anisopliae ICIPE 20 were used in combination, indicating an additive impact on the target pest; however, field validation can shed more light on this outcome.