Widespread Triploidy in Western North American Aspen (Populus tremuloides)

We document high rates of triploidy in aspen (Populus tremuloides) across the western USA (up to 69% of genets), and ask whether the incidence of triploidy across the species range corresponds with latitude, glacial history (as has been documented in other species), climate, or regional variance in clone size. Using a combination of microsatellite genotyping, flow cytometry, and cytology, we demonstrate that triploidy is highest in unglaciated, drought-prone regions of North America, where the largest clone sizes have been reported for this species. While we cannot completely rule out a low incidence of undetected aneuploidy, tetraploidy or duplicated loci, our evidence suggests that these phenomena are unlikely to be significant contributors to our observed patterns. We suggest that the distribution of triploid aspen is due to a positive synergy between triploidy and ecological factors driving clonality. Although triploids are expected to have low fertility, they are hypothesized to be an evolutionary link to sexual tetraploidy. Thus, interactions between clonality and polyploidy may be a broadly important component of geographic speciation patterns in perennial plants. Further, cytotypes are expected to show physiological and structural differences which may influence susceptibility to ecological factors such as drought, and we suggest that cytotype may be a significant and previously overlooked factor in recent patterns of high aspen mortality in the southwestern portion of the species range. Finally, triploidy should be carefully considered as a source of variance in genomic and ecological studies of aspen, particularly in western U.S. landscapes.     

High incidence of asymptomatic cases during an outbreak of Plasmodium malariae in a remote village of Malaysian Borneo

An outbreak of Plasmodium malariae occurred in Sonsogon Paliu village in the remote area of Ulu Bengkoka sub-district of Kota Marudu, Northern Sabah, Malaysian Borneo from July through August 2019. This was the first outbreak of malaria in this village since 2014. On 11^th July 2019 the Kota Kinabalu Public Health Laboratory notified the Kota Marudu District Health Office of a Polymerase Chain Reaction (PCR) positive case of P. malariae. This index case was a male from Sulawesi, Indonesia working for a logging company operating in Sonsogon Paliu. During the resulting outbreak, a total of 14 symptomatic cases were detected. All of these cases were positive by thick and thin blood smear examination, and also by PCR. During the outbreak, a mass blood survey screening was performed by light-microscopy and PCR. A total of 94 asymptomatic villagers 31 (33.0%) were PCR positive but thick and thin blood smear negative for P. malariae. Both symptomatic and asymptomatic cases received treatment at the district hospital. When symptomatic and asymptomatic cases were considered together, males (29/45. 64.5%) were infected more than females (16/45, 35.6%), the male:female ratio being 1.8:1. Adults were the predominant age group infected (22/45, 48.9%) followed by adolescents (19/45, 42.2%) and children under five years of age (4/45, 8.9%). This report illustrates that symptomatic and submicroscopic cases pose a challenge during P. malariae outbreaks and that PCR is a valuable tool for their identification. The rapid identification and control of imported malaria is crucial for the continued control of malaria in Malaysia.     

Characterization of Polar and Non‐Polar Compounds of House Edible Bird's Nest (EBN) from Johor,Malaysia

This work investigated the polar (PC: protein, amino acid and metabolite) and non‐polar (NPC: fatty acid) compounds and bioactivity characteristics of the EBN harvested from the state of Johor in Malaysia. The electrophoretic gels exhibited 15 protein bands (16–173 kD) with unique protein profile. Amino acids analysis by AccQ?Tag method revealed 18 types of amino acids in EBN. Metabolite profiling was performed using High‐Performance Liquid Chromatography coupled with Quadrupole Time‐of‐Flight Mass Spectrometer (HPLC‐QTOF/MS) technique and a total of 54 compounds belonging to different groups were detected and identified. These findings help to uncover the relation of therapeutic activity of EBN. The EBN was further extracted with AcOEt and BuOH. The AcOEt extract was fractionated into three fractions (F₁?F₃), and the high triglyceride content in F₂ was verified by gC‐FID. The three groups of fatty acids discovered in EBN are 48.43 % of poly‐unsaturated (PUFA), 25.35 % of saturated fatty acids (SFA) and 24.74 % of mono‐unsaturated fat (MUFA). This is the first time to report results ofEBN, BuOH, and AcOEt extracts and of fraction F₂ (TEBN) on their analysis for their antioxidant activities by DPPH, ABTS and catalase assay and for their paraoxonase and anti‐tyrosinase activities. The results showed that TEBN exhibited the significant bioactivity in all assays. These findings suggest that TEBN is a good source for natural bioactive compounds in promoting body vigor. Current work widened the content of EBN especially on the triglyceride and also marked the content of specific location (Johor, Malaysia) of EBN origin.     

Contribution of P2X4 receptor in pain associated with rheumatoid arthritis: a review

Purinergic Signalling - Pain is the most common symptom reported by patients with rheumatoid arthritis (RA) even after the resolution of chronic joint inflammation. It is believed that...     

Stochastic multi-scale prediction on the apparent elastic moduli of trabecular bone considering uncertainties of biological apatite (BAp) crystallite orientation and image-based modelling

An assessment of the mechanical properties of trabecular bone is important in determining the fracture risk of human bones. Many uncertainty factors contribute to the dispersion of the estimated mechanical properties of trabecular bone. This study was undertaken in order to propose a computational scheme that will be able to predict the effective apparent elastic moduli of trabecular bone considering the uncertainties that are primarily caused by image-based modelling and trabecular stiffness orientation. The effect of image-based modelling which focused on the connectivity was also investigated. A stochastic multi-scale method using a first-order perturbation-based and asymptotic homogenisation theory was applied to formulate the stochastically apparent elastic properties of trabecular bone. The effective apparent elastic modulus was predicted with the introduction of a coefficient factor to represent the variation of bone characteristics due to inter-individual differences. The mean value of the predicted effective apparent Young's modulus in principal axis was found at approximately 460 MPa for respective 15.24% of bone volume fraction, and this is in good agreement with other experimental results. The proposed method may provide a reference for the reliable evaluation of the prediction of the apparent elastic properties of trabecular bone.     

Arabidopsis ERG28 Tethers the Sterol C4-Demethylation Complex to Prevent Accumulation of a Biosynthetic Intermediate That Interferes with Polar Auxin Transport

Sterols are vital for cellular functions and eukaryotic development because of their essential role as membrane constituents. Sterol biosynthetic intermediates (SBIs) represent a potential reservoir of signaling molecules in mammals and fungi, but little is known about their functions in plants. SBIs are derived from the sterol C4-demethylation enzyme complex that is tethered to the membrane by Ergosterol biosynthetic protein28 (ERG28). Here, using nonlethal loss-of-function strategies focused on Arabidopsis thaliana ERG28, we found that the previously undetected SBI 4-carboxy-4-methyl-24-methylenecycloartanol (CMMC) inhibits polar auxin transport (PAT), a key mechanism by which the phytohormone auxin regulates several aspects of plant growth, including development and responses to environmental factors. The induced accumulation of CMMC in Arabidopsis erg28 plants was associated with diagnostic hallmarks of altered PAT, including the differentiation of pin-like inflorescence, loss of apical dominance, leaf fusion, and reduced root growth. PAT inhibition by CMMC occurs in a brassinosteroid-independent manner. The data presented show that ERG28 is required for PAT in plants. Furthermore, it is accumulation of an atypical SBI that may act to negatively regulate PAT in plants. Hence, the sterol pathway offers further prospects for mining new target molecules that could regulate plant development.     

Burden of Giardia duodenalis Infection and Its Adverse Effects on Growth of Schoolchildren in Rural Malaysia

Background

Giardia duodenalis infection and malnutrition are still considered as public health problems in many developing countries especially among children in rural communities. This study was carried out among Aboriginal (Orang Asli) primary schoolchildren in rural peninsular Malaysia to investigate the burden and the effects of Giardia infection on growth (weight and height) of the children.

Methods/Findings

Weight and height of 374 children aged 7–12 years were assessed before and after treatment of Giardia infection. The children were screened for Giardia parasite using trichrome staining technique. Demographic and socioeconomic data were collected via face-to-face interviews using a pre-tested questionnaire. Overall, 22.2% (83/374) of the children were found to be infected with Giardia. Nutritional status of children was assessed and the results showed that the mean weight and height were 23.9 kg (95% CI = 23.3, 24.5) and 126.6 cm (95% CI = 125.6, 127.5), respectively. Overall, the prevalence of severe underweight, stunting and wasting were 28.3%, 23.8% and 21.0%, respectively. Multiple linear regression analyses showed sex, Giardia infection and household monthly income as the significant determinants of weight while sex and level of mother''s education were the significant determinants of height. Weight and height were assessed at 3 and 6 months after treatment of Giardia infection. It was found that Giardia infection has a significant association with the weight of children but not with height.

Conclusions/Significance

This study reveals high prevalence of Giardia infection and malnutrition among Aboriginal children in rural Malaysia and clearly highlights an urgent need to identify integrated measures to control these health problems in the rural communities. Essentially, proper attention should be given to the control of Giardia infection in Aboriginal communities as this constitutes one of the strategies to improve the nutritional status of Aboriginal children.     

New Insights of Microsporidial Infection among Asymptomatic Aboriginal Population in Malaysia

Background

Studies on microsporidial infection mostly focus on immunodeficiency or immunosuppressive individuals. Therefore, this cross-sectional study describes the prevalence and risk factors of microsporidiosis among asymptomatic individuals in Malaysia.

Methods/Findings

Four hundred and forty seven stool samples were collected and examined for microsporidia after staining with Gram-chromotrope Kinyoun. Demographic, socioeconomic, environmental, and behavioral information were collected by using a pre-tested questionnaire. Overall, 67 (15%) samples were positive for microsporidia. The prevalence of infection was significantly higher among individuals aged more than 15 years compared to those aged <15 years (OR = 1.97, 95% CI = 1.08, 3.62; P = 0.028). Furthermore, logistic regression analysis confirmed that the presence of other family members infected with microsporidia (OR = 8.45; 95% CI = 4.30, 16.62; P<0.001) and being a consumer of raw vegetables (OR = 2.05; 95% CI = 1.15, 3.66; P = 0.016) were the significant risk factors of this infection.

Conclusions

These findings clearly show that exposure to microsporidia is common among Aboriginal population. Further studies using molecular approach on microsporidia isolates from asymptomatic individuals is needed to determine species-specific. The risk factors associated with microsporidiosis will help in identifying more clearly the sources of the infection in the environment that pose a risk for transmission so that preventive strategies can be implemented.     

Identification and QTL mapping of whitefly resistance components in Solanum galapagense

Solanum galapagense is closely related to the cultivated tomato and can show a very good resistance towards whitefly. A segregating population resulting from a cross between the cultivated tomato and a whitefly resistant S. galapagense was created and used for mapping whitefly resistance and related traits, which made it possible to study the genetic basis of the resistance. Quantitative trait loci (QTL) for adult survival co-localized with type IV trichome characteristics (presence, density, gland longevity and gland size). A major QTL (Wf-1) was found for adult survival and trichome characters on Chromosome 2. This QTL explained 54.1 % of the variation in adult survival and 81.5 % of the occurrence of type IV trichomes. A minor QTL (Wf-2) for adult survival and trichome characters was identified on Chromosome 9. The major QTL was confirmed in F3 populations. Comprehensive metabolomics, based on GCMS profiling, revealed that 16 metabolites segregating in the F2 mapping population were associated with Wf-1 and/or Wf-2. Analysis of the 10 most resistant and susceptible F2 genotypes by LCMS showed that several acyl sugars were present in significantly higher concentration in the whitefly resistant genotypes, suggesting a role for these components in the resistance as well. Our results show that whitefly resistance in S. galapagense seems to inherit relatively simple compared to whitefly resistance from other sources and this offers great prospects for resistance breeding as well as elucidating the underlying molecular mechanism(s) of the resistance.