254 research outputs found
Poverty reduction through irrigation and smallholder markets (PRISM)
Manual pumpsDrip irrigationWater storage
Examining Autoexposure for Challenging Scenes
Autoexposure (AE) is a critical step applied by camera systems to ensure
properly exposed images. While current AE algorithms are effective in well-lit
environments with constant illumination, these algorithms still struggle in
environments with bright light sources or scenes with abrupt changes in
lighting. A significant hurdle in developing new AE algorithms for challenging
environments, especially those with time-varying lighting, is the lack of
suitable image datasets. To address this issue, we have captured a new 4D
exposure dataset that provides a large solution space (i.e., shutter speed
range from (1/500 to 15 seconds) over a temporal sequence with moving objects,
bright lights, and varying lighting. In addition, we have designed a software
platform to allow AE algorithms to be used in a plug-and-play manner with the
dataset. Our dataset and associate platform enable repeatable evaluation of
different AE algorithms and provide a much-needed starting point to develop
better AE methods. We examine several existing AE strategies using our dataset
and show that most users prefer a simple saliency method for challenging
lighting conditions.Comment: ICCV 202
Vaccination with Schistosoma mansoni cholinesterases reduces the parasite burden and egg viability in a mouse model of Schistosomiasis
Schistosomiasis is a neglected tropical disease caused by parasitic blood flukes of the genus Schistosoma, which kills 300,000 people every year in developing countries, and there is no vaccine. Recently, we have shown that cholinesterases (ChEs)âenzymes that regulate neurotransmissionâfrom Schistosoma mansoni are expressed on the outer tegument surface and present in the excretory/secretory products of larval schistosomula and adult worms, and are essential for parasite survival in the definitive host, highlighting their utility as potential schistosomiasis vaccine targets. When treated in vitro with anti-schistosome cholinesterase (SmChE) IgG, both schistosomula and adult worms displayed significantly decreased ChE activity, which eventually resulted in parasite death. Vaccination with individual SmChEs, or a combination of all three SmChEs, significantly reduced worm burdens in two independent trials compared to controls. Average adult worm numbers and liver egg burdens were significantly decreased for all vaccinated mice across both trials, with values of 29â39% and 13â46%, respectively, except for those vaccinated with SmAChE1 in trial 1. Egg viability, as determined by egg hatching from liver homogenates, was significantly reduced in the groups vaccinated with the SmChE cocktail (40%) and SmAChE2 (46%). Furthermore, surviving worms from each vaccinated group were significantly stunted and depleted of glycogen stores, compared to controls. These results suggest that SmChEs could be incorporated into a vaccine against schistosomiasis to reduce the pathology and transmission of this debilitating disease
Novel cholinesterase paralogs of Schistosoma mansoni have perceived roles in cholinergic signaling and drug detoxification and are essential for parasite survival
Cholinesterase (ChE) function in schistosomes is essential for orchestration of parasite neurotransmission but has been poorly defined with respect to the molecules responsible. Interrogation of the S. mansoni genome has revealed the presence of three ChE domain-containing genes (Smche)s, which we have shown to encode two functional acetylcholinesterases (AChE)s (Smache1 -smp_154600 and Smache2 -smp_136690) and a butyrylcholinesterase (BChE) (Smbche1 -smp_125350). Antibodies to recombinant forms of each SmChE localized the proteins to the tegument of adults and schistosomula and developmental expression profiling differed among the three molecules, suggestive of functions extending beyond traditional cholinergic signaling. For the first time in schistosomes, we identified ChE enzymatic activity in fluke excretory/secretory (ES) products and, using proteomic approaches, attributed this activity to the presence of SmAChE1 and SmBChE1. Parasite survival in vitro and in vivo was significantly impaired by silencing of each smche, either individually or in combination, attesting to the essential roles of these molecules. Lastly, in the first characterization study of a BChE from helminths, evidence is provided that SmBChE1 may act as a bio-scavenger of AChE inhibitors as the addition of recombinant SmBChE1 to parasite cultures mitigated the effect of the anti-schistosome AChE inhibitor 2,2- dichlorovinyl dimethyl phosphate-dichlorvos (DDVP), whereas smbche1-silenced parasites displayed increased sensitivity to DDVP.Funding: The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This work was funded by NHMRC program grant APP1037304, an NHMRC Senior Principal Research Fellowship (APP1117504) to A.L. and a James Cook University Postgraduate Scholarship to B.T
Secreted and surface proteome and transcriptome of Opisthorchis felineus
Introduction: Opisthorchis felineus, Opisthorchis viverrini, and Clonorchis sinensis are the most medically important species of fish-borne zoonotic trematodes. O. felineus is endemic to the river plains of Western Siberia and Eastern Europe, and it is estimated that more than 1.6 million people could be infected with this parasite. Chronic opisthorchiasis may lead to significant gastrointestinal and hepatobiliary pathology. This study aimed to identify and characterize proteins from the secreted and tegumental proteomes of O. felineus. Methods: Adult flukes were collected from experimentally infected hamsters and cultured in vitro in serum-free media. We extracted proteins from different compartments of the O. felineus secretome, including (i) soluble excretory/secretory (ES) products; (ii) secreted 15K-extracellular vesicles (EVs); and (iii) tegument. Results: We also generated a transcriptome using long-read sequencing, and when this was combined with high-resolution mass spectrometry, sodium dodecyl sulfateâpolyacrylamide gel electrophoresis (SDS-PAGE) separation, and protein digestion, we identified 686, 894, 389, 324, and 165 proteins from the ES, 15K-EV, and the three sequentially extracted tegument (TEG) protein fractions, respectively. We conducted in-depth gene ontology and protein family analyses on the identified proteins and discussed comparisons against similar proteome data sets acquired for the Southeast Asian liver fluke O. viverrini and the Chinese liver fluke C. sinensis. Discussion: The information from this study will form a biologically relevant data set of O. felineus proteins that could be used to develop diagnostic and therapeutic tools to manage the human cost of O. felineus infection and its associated comorbidities.This project has been funded by the Australian National Health and Medical Research council e-ASIA Joint Research Program APP1185434. AL is supported by a Level Three NHMRC Investigator Grant APP2008450. OF and EK are supported by a RFBR Grant 19-515-70004. JS is supported by a Ramon y Cajal fellowship (RYC2021-032443-I) from the Ministerio de Ciencia e Innovacion in Spain.S
High frequency detection of Toxoplasma gondii DNA in human neonatal tissue from Libya
Background:
Toxoplasma gondii is a parasite that causes significant disease in humans. Toxoplasmosis is normally asymptomatic, unless associated with congenital transmission, or in immunocompromised people. Congenital transmission generally occurs at low frequencies. In this study, we use PCR to investigate possible congenital transmission of T. gondii during pregnancy in a cohort of mothers from Libya.
Methods:
Two hundred and seventy two pregnant women (producing 276 neonates) were recruited to obtain umbilical cord tissue from their neonates at birth. DNA was extracted from umbilical cord tissue and tested for T. gondii DNA using two specific PCR protocols based on the sag 1 and sag 3 genes.
Results:
Toxoplasma gondii DNA was detected in the umbilical cord DNA from 27 of the 276 neonates giving a prevalence of 9.9% (95% CI: 6.8-13.9%). Compared with more commonly reported rates of congenital transmission of 0.1% of live births, this is high. There was no association of infection with unsuccessful pregnancy.
Conclusions:
This study shows a high frequency presence of T. gondii DNA associated with neonatal tissue at birth in this cohort of 276 neonates from Libya. Although PCR cannot detect living parasites, there is the possibility that this indicates a higher than usual frequency of congenital transmission
Podoconiosis and soil-transmitted helminths (STHs): double burden of neglected tropical diseases in Wolaita zone, rural southern Ethiopia
Background
Both podoconiosis and soil-transmitted helminth (STH) infections occur among barefoot people in areas of extreme poverty; however, their co-morbidity has not previously been investigated. We explored the overlap of STH infection and podoconiosis in Southern Ethiopia and quantified their separate and combined effects on prevalent anemia and hemoglobin levels in podoconiosis patients and health controls from the same area.
Methods and Principal Findings
A two-part comparative cross-sectional study was conducted in Wolaita zone, southern Ethiopia. Data were collected from adult patients presenting with clinically confirmed podoconiosis, and unmatched adult neighborhood controls living in the same administrative area. Information on demographic and selected lifestyle factors was collected using interviewer-administered questionnaires. Stool samples were collected and examined qualitatively using the modified formalin-ether sedimentation method. Hemoglobin level was determined using two different methods: hemoglobinometer and automated hematology analyzer. A total of 913 study subjects (677 podoconiosis patients and 236 controls) participated. The prevalence of any STH infection was 47.6% among patients and 33.1% among controls (p<0.001). The prevalence of both hookworm and Trichuris trichiura infections was significantly higher in podoconiosis patients than in controls (AOR 1.74, 95% CI 1.25 to2.42, AOR 6.53, 95% CI 2.34 to 18.22, respectively). Not wearing shoes and being a farmer remained significant independent predictors of infection with any STH. There was a significant interaction between STH infection and podoconiosis on reduction of hemoglobin level (interaction p value = 0.002).
Conclusions
Prevalence of any STH and hookworm infection was higher among podoconiosis patients than among controls. A significant reduction in hemoglobin level was observed among podoconiosis patients co-infected with hookworm and ânon-hookworm STHâ. Promotion of consistent shoe-wearing practices may have double advantages in controlling both podoconiosis and hookworm infection in the study area
Characterisation of tetraspanins from Schistosoma haematobium and evaluation of their potential as novel diagnostic markers
Schistosoma haematobium is the leading cause of urogenital schistosomiasis and it is recognised as a class 1 carcinogen due to the robust association of infection with bladder cancer. In schistosomes, tetraspanins (TSPs) are abundantly present in different parasite proteomes and could be potential diagnostic candidates due to their accessibility to the host immune system. The large extracellular loops of six TSPs from the secretome (including the soluble excretory/secretory products, tegument and extracellular vesicles) of S. haematobium (Sh-TSP-2, Sh-TSP-4, Sh-TSP-5, Sh-TSP-6, Sh-TSP-18 and Sh-TSP-23) were expressed in a bacterial expression system and polyclonal antibodies were raised to the recombinant proteins to confirm the anatomical sites of expression within the parasite. Sh-TSP-2, and Sh-TSP-18 were identified on the tegument, whereas Sh-TSP-4, Sh-TSP-5, Sh-TSP-6 and Sh-TSP-23 were identified both on the tegument and internal tissues of adult parasites. The mRNAs encoding these TSPs were differentially expressed throughout all schistosome developmental stages tested. The potential diagnostic value of three of these Sh-TSPs was assessed using the urine of individuals (stratified by infection intensity) from an endemic area of Zimbabwe. The three Sh-TSPs were the targets of urine IgG responses in all cohorts, including individuals with very low levels of infection (those positive for circulating anodic antigen but negative for eggs by microscopy). This study provides new antigen candidates to immunologically diagnose S. haematobium infection, and the work presented here provides compelling evidence for the use of a biomarker signature to enhance the diagnostic capability of these tetraspanins
Improved thyroid hypoechogenicity following bariatric-induced weight loss in euthyroid adults with severe Obesity-a pilot study
Background: Obesity may affect both biochemical thyroid function tests; and thyroid morphology, as assessed using ultrasound scans (US). The aim of the present pilot study was to explore whether weight loss achieved by bariatric surgery alters thyroid US morphology including gray-scale measurements; and/or function in euthyroid adults with severe obesity. Methods: Euthyroid adults (> 18 years) with body mass index (BMI) â„40 kg/m2 and negative thyroid peroxidase antibodies were assessed at baseline (pre-surgery) and after achieving at least 5% weight loss of their baseline body weight following bariatric surgery. Anthropometric assessments, biochemical/hormonal measurements (TSH, free-T4, free-T3, reverse-T3, and leptin) and thyroid US with gray-scale histogram analysis were performed at the baseline and post-surgery follow-up. Results: Ten Caucasian, euthyroid patients (women/men: 8/2; age: 48.6 ± 3.1 years; BMI: 51.4 ± 1.8 kg/m2) successfully completed this study with significantly decreased body weight (> 5% weight loss), waist circumference and serum leptin levels post-surgery (mean post-surgery follow-up duration: 16.5 ± 2.5 months). In parallel to the observed bariatric-induced weight loss, thyroid US echogenicity increased by 25% (p = 0.03), without significant changes in thyroid volume. No significant changes in thyroid function tests were detected. No significant correlations were observed between the increase in thyroid echogenicity and the decreases in anthropometric parameters and circulating leptin. Conclusion: Our results indicate that in euthyroid adults with severe obesity, marked weight loss achieved by bariatric surgery is associated with a parallel significant increase in the thyroid US echogenicity, suggesting that morphological changes of the thyroid in obesity are reversible with weight loss
- âŠ