Impact of Toxoplasma gondii infection on human health

Toxoplasmosis is one of the most prevalent infectious disease around the globe and it is caused by the parasite named Toxoplasma gondii. Infections normally lead to asymptomatic parasite persistence in immunocompetent warm-blooded hosts, including up to 30-50% of humans. However, T. gondii infection has also a major medical concern and can lead to life-threatening diseases, after reactivation in immunocompromized individuals, particularly in patients with human immunodeficiency virus/cancer or organ transplant recipients, after vertical transmission to fetuses of pregnant women and by inducing recurrent uveitis in immunocompetent adults. More importantly, T. gondii undergoes stage conversion from its fast-replicating tachyzoite to slow replicating dormant bradyzoite preferentially in the brain and skeletal muscles, and lesser extent in the eye, liver, kidney and lung which enable the parasite to persist for the whole life of an individual. Due to the persistence behavior of the parasite in different parts of human body, T. gondii can develop multiple human diseases with severe clinical symptoms. In this study, we have summarized the association of T. gondii in multiple human diseases for instance Encephalitis, Parkinson’s disease, Schizophrenia, Heart disease, Ocular Toxoplasmosis, Congenital abnormalities, Cancer and Diabetes. This highlights the potential role of T. gondii in developing fatal diseases, particularly in immunocompromised individuals despite having asymptomatic nature of the parasite. Bioresearch Commu. 8(1): 1093-1099, 2022 (January)

Seedbank persistence and emergence pattern of Argemone mexicana, Rapistrum rugosum and Sonchus oleraceus in the eastern grain region of Australia

A thorough understanding of the emergence pattern and persistence of weed seeds is a prerequisite in framing appropriate weed management options for noxious weeds. In a study conducted at the University of Queensland, Australia, the emergence and seed persistence behavior of three major weeds Sonchus oleraceous, Rapistrum rugosum, and Argemone mexicana were explored with seeds collected from Gatton and St George, Queensland, Australia, with an average annual rainfall of 760 and 470 mm, respectively. Seed persistence was evaluated by placing seeds at the surface layer (0 cm) or buried at 2 and 10 cm depths enclosed in nylon mesh bags and examined their viability for 42 months. In another study, the emergence pattern of four populations, each from these two locations, was evaluated under a rainfed environment in trays. In the mesh-bag study, rapid depletion of seed viability of S. oleraceous from the surface layer (within 18 months) and lack of seed persistence beyond two years from 2 and 10 cm depths were observed. In trays, S. oleraceous germinated 3 months after seeding in response to summer rains and there was progressive germination throughout the winter season reaching cumulative germination ranging from 22 to 29% for all the populations. In the mesh-bag study, it took about 30 months for the viability of seeds of R. rugosum to deplete at the surface layer and a proportion of seeds (5 to 13%) remained viable at 2 and 10 cm depths even at 42 months. Although fresh seeds of R. rugosum exhibit dormancy imposed due to the hard seed coat, a proportion of seeds germinated during the summer months in response to summer rains. Rapid loss of seed viability was observed for A. mexicana from the surface layer; however, more than 30% of the seeds were persistent at 2 and 10 cm depths at 42 months. Notably, poor emergence was observed for A. mexicana in trays and that was mostly confined to the winter season.

Self-deprecating humor and task persistence: the moderating role of self-defeating humor style

Over the past two decades a significant body of research has examined the effects of individual differences in humor style or humor occurrences (e.g. specific jokes, memes) on behavior. However, research examining whether these individual differences in humor styles influence the effects of humor occurrences on work behaviors has been scant. Drawing on Conservations of Resources (COR) theory, this paper seeks to fill this gap by examining one form of humor, self-deprecating humor, and its interaction with self-defeating humor style to influence task persistence behavior. Findings from an experimental study of 124 management students show that self-deprecating humor can bolster a person’s persistence at an assigned task. Findings also show that individual differences in self-defeating humor style influence the relationship between self-deprecating humor and persistence. Individuals low in self-defeating humor style show a significant increase in persistence while those high in self-defeating humor style did not show any significant increase.

Persistence, dissipation behavior and health risk assessment of spiromesifen in brinjal (Solanum melongena L.) by LC-MS/MS

Brinjal (Solanum melongena) is a versatile crop infected by several insects and pests. For the control of these pests, spiromesifen insecticide has been in use to reduce the damage and increase crop production worldwide. Therefore, a field trial was conducted to study dissipation and persistence behavior of spiromesifen 22.9% w/w SC in/on brinjal at the recommended dose (RD) 96 g a.i./ha and double to recommended dose 192 g a.i./ha (2RD). The quantitative analysis of spiromesifen was performed using ultra-high performance liquid chromatography- tandem mass spectrometry (UHPLC-MS/MS). Samples were processed by the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method. The analytical method was validated using various parameters viz., linearity (R2≥0.99), sensitivity (LOD and LOQ), accuracy (recovery=70-120%) and precision (RSD≤20%). The spiroemsifen persisted up to 3 days at RD and 5 days at 2RD. The dissipation half-life (DT50) of spriromesifen was 3.64 and 4.10 days at RD and 2RD in brinjal, respectively. However, residues of spiromesifen measured from soil at 0th (2 hr) day and 10th day were below the limit of quantification (BQL). The waiting period deciphered for spiromesifen applied in brinjal was 1 day at the recommended dose. Further, health risk assessment (health risk index<1 and percent health index<100) was performed on the basis of field trial which suggested that the application of spiromesifen in brinjal crop at recommended dose is safe for the end-users.

Persistence behavior in African trypanosomes during adipose tissue colonization

Persistence is an important and ancient evolutionary adaptive mechanism used by several organisms to survive environmental changes. During its life cycle Trypanosoma brucei, the causative agent of sleeping sickness, inhabits several microenvironments, including the adipose tissue. Here we used a mathematical model to investigate how this large parasite reservoir contributes to the global parasite population dynamics. By modeling the total number of parasites and the proportion of transmissible forms in the blood and the adipose tissue during an infection, we estimated that adipose tissue parasites proliferate more slowly. Intravital microscopy of parasites stained with CellTraceTM Violet confirmed that adipose tissue forms divide twice slower than the blood counterparts. Consistent with a reduced growth, proteome analysis revealed that adipose tissue forms undergo a metabolic adaptation and downregulate proteins involved in translation. Quantification of protein synthesis using L-Homopropargylglycine confirmed that this rate is 24% lower in adipose tissue forms. We propose that in adipose tissue, T. brucei acquire a persistence-like behavior, which could contribute to disease chronicity and treatment failure.

An evaluation of online students’ persistence intentions

PurposeThe high dropout rate among online learning students is a serious issue. Using the theory of planned behavior as a framework, this study investigates what effect attitude, opinion of others and perceived ease of online learning technologies leave on Pakistani online students' persistence intentions.Design/methodology/approachThe sample of this study comprises 320 students enrolled at a distance learning university in Pakistan. Online questionnaires are used to gather data for the study. Correlations and regression analysis are run to figure out the effect of independent variables on the dependent variable of the study.FindingsThe findings of the study show that 51% variance in online students’ persistence intentions can be explained by personal attitude, subjective norms and perceived behavioral control.Research limitations/implicationsThe use of a non-random sampling technique along with a cross-sectional design form the major limitations of the study.Practical implicationsThe outcome of the study may help online education providers as well as policymakers to design programs and initiatives to improve students’ retention in online study programs.Originality/valueThe study contributed to the extant literature by finding out Pakistani online students’ persistence behavior is affected by their attitude, subjective norms and perceived ease of online learning. The study also found that the opinion of people closely related to students influences their study persistence decisions.

The Effects of Long-term Mask Wearing on Aesthetic Behavior: Focusing on the COVID-19 pandemic

This study attempted to examine self-skin recognition and aesthetic behavior as well as providing basic data needed to develop strategies in preparation for the post-COVID-19 era in the beauty industry. For this, an online survey was performed among a total of 150 adult men and women aged 20 or older who have worn a mask regularly during the COVID-19 pandemic, and the results of the survey revealed the following: First, mask-wearing intention had a positive influence on mask-wearing experiences. Second, in self-skin recognition, mask-wearing revealed a significant effect on the recognition of causes of skin problems, but no significant influence was found in recognition of skin problem symptoms. Third, mask-wearing had a statistically significant effect on hygienic attitudes, but no significant influence on skin problem-solving attitudes or makeup application attitudes. Fourth, mask-wearing had a statistically significant effect on care-persistence behavior, but no significant influence on skin aesthetic consumption. Fifth, according to the analysis of differences in mask-wearing intention and experiences, self-skin recognition, aesthetic attitude, and aesthetic behavioral intention by gender, a statistically significant difference was found among all items. In terms of post-COVID-19 strategies in the beauty industry, this study suggests a necessity of promoting online education and consultation based on skin knowledge, introducing and improving service providers’ competencies, establishing hygienic environments, and developing new programs, which are difficult to implement at home.