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.     

Estimation of linear and mass attenuation coefficients of soy–lignin bonded Rhizophora spp. particleboard as a potential phantom material using caesium-137 and cobalt-60

In this study, linear and mass attenuation coefficients of fabricated particleboards intended for use as phantom material were estimated using ¹³⁷Cs and ⁶⁰Co radiation sources. Particleboards made of Rhizophora spp. wood trunk bonded with soy flour and lignin were fabricated at a target density of 1.0 g cm^?3, with and without gloss finish coating. Elemental composition of the particleboards was obtained by means of energy dispersive X-ray (EDX) spectroscopy. Experimental setups were simulated via the GATE Monte Carlo (MC) package, with particle histories of 1?×?10⁶–1?×?10⁷. Linear and mass attenuation coefficients obtained from measurements and GATE simulations were compared and discussed. The percentage differences between the measured and simulated linear and mass attenuation coefficients of the samples were reasonably small (2.05–4.88% for ¹³⁷Cs and 3.24–5.38% for ⁶⁰Co). It is shown that all the particleboards have the potential to be used as phantom materials as the attenuation coefficients measured were in good agreement with those of water (calculated with XCOM) and with those simulated with the GATE toolkit. The use of gloss finish coating also did not show any significant effect on the attenuation coefficient of the phantom material. Verification of experimental results via GATE simulations has been shown crucial in providing reliable data for energy transmission studies. Based on the results achieved in this study, it is concluded that the studied material—Rhizophora spp. wood trunk bonded with soy flour and lignin including gloss finish coating—can be used in radiation dosimetry studies.

     

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.     

Comparative analysis of bioactive phytochemicals from Scutellaria baicalensis, Scutellaria lateriflora, Scutellaria racemosa, Scutellaria tomentosa and Scutellaria wrightii by LC-DAD-MS

Scutellaria is a geographically widespread and diverse genus of the Lamiaceae family of herbaceous plants commonly known as skullcaps. Scutellaria is used widely as an ethnobotanical herb for the treatment of various ailments ranging from cancers, cirrhosis, jaundice, hepatitis, anxiety and nervous disorders. We used (1) reverse-phase liquid chromatography coupled to a diode array detector (LC-DAD), and (2) multiple reaction monitoring (MRM) using mass spectrometry (LC-MS/MS) to quantify the levels of acteoside, scutellarin, scetellarein, baicalin, baicalein, wogonin, wogonoside, apigenin, chrysin, and oroxylin A in aqueous methanolic extracts of roots, shoots and leaves of S. baicalensis, S. lateriflora, S. racemosa, S. tomentosa and S. wrightii. Our results indicate that both methods (LC-DAD and LC-MS/MS) were robust for the detection of the 10 analytes from Scutellaria extracts although greater sensitivities were achieved using LC-MS/MS in MRM mode. MRM enabled the detection of low levels of analytes which were otherwise undetected using LC-DAD. The baicalin content of S. wrightii roots were 5-fold higher than the commonly used S. baicalensis. Additionally, we also showed that leaves of both S. wrightii and S. tomentosa are good sources of scutellarin compared to S. baicalensis. Our data clearly demonstrated that previously uncharacterized species, S. wrightii and S. tomentosa are both good sources of flavonoids, particularly scutellarin, baicalin, wogonin and baicalein.     

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.     

Classification of hybrid and altered Vibrio cholerae strains by CTX prophage and RS1 element structure

Analysis of the CTX prophage and RS1 element in hybrid and altered Vibrio cholera O1 strains showed two classifiable groups. Group I strains contain a tandem repeat of classical CTX prophage on the small chromosome. Strains in this group either contain no element(s) or an additional CTX prophage or RS1 element(s) on the large chromosome. Group II strains harbor RS1 and CTX prophage, which has an E1 Tor type rstR and classical ctxB on the large chromosome.     

Influence of limited proteolysis,detergent treatment and lyophilization on the phenoloxidase activity of Rapana thomasiana hemocyanin

The intrinsic and inducible phenoloxidase (PO) activity of Rapana thomasiana hemocyanin (RtH) and its substructures were studied. With catechol as substrate, a weak o-diPO activity was measured for the didecameric RtH and its subunits. Some activation of the o-diPO activity of RtH was achieved by limited treatment with subtilisin and by incubation of RtH with 2.9 mM sodium dodecyl sulphate (SDS), suggesting an enhanced substrate access to the active sites. The highest artificial induction of o-diPO activity in RtH, however, was obtained by lyophilization of the protein. This is ascribed to conformational changes during the lyophilization process of the didecameric RtH molecules, affecting the accessibility of the active sites. These conformational changes must be very small, since Fourier-transform infrared and circular dichroism spectroscopies did not reveal any changes in secondary structure of lyophilized RtH. The difference in accessibility of the copper containing active site for substrates between catechol oxidase and functional unit RtH2-e was demonstrated by molecular modeling and surface area accessibility calculations. The low level of intrinsic PO activity in the investigated hemocyanin is related to the inaccessibility of the binuclear copper active sites to the substrates.     

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.