Quantifying the effect of soil moisture content on segmenting root system architecture in X-ray computed tomography images

Aims

A commonly accepted challenge when visualising plant roots in X-ray micro Computed Tomography (μCT) images is the similar X-ray attenuation of plant roots and soil phases. Soil moisture content remains a recognised, yet currently uncharacterised source of segmentation error. This work sought to quantify the effect of soil moisture content on the ability to segment roots from soil in μCT images.

Methods

Rice (Oryza sativa) plants grown in contrasting soils (loamy sand and clay loam) were μCT scanned daily for nine days whilst drying from saturation. Root volumes were segmented from μCT images and compared with volumes derived by root washing.

Results

At saturation the overlapping attenuation values of root material, water-filled soil pores and soil organic matter significantly hindered segmentation. However, in dry soil (ca. six days of drying post-saturation) the air-filled pores increased image noise adjacent to roots and impeded accurate visualisation of root material. The root volume was most accurately segmented at field capacity.

Conclusions

Root volumes can be accurately segmented from μCT images of undisturbed soil without compromising the growth requirements of the plant providing soil moisture content is kept at field capacity. We propose all future studies in this area should consider the error associated with scanning at different soil moisture contents.     

Emergence of gp120 V3 Variants Confers Neutralization Resistance in an R5 Simian-Human Immunodeficiency Virus-Infected Macaque Elite Neutralizer That Targets the N332 Glycan of the Human Immunodeficiency Virus Type 1 Envelope Glycoprotein

Neutralization-resistant simian-human immunodeficiency virus AD8 (SHIV_AD8) variants that emerged in an infected macaque elite neutralizer targeting the human immunodeficiency virus type 1 (HIV-1) gp120 N332 glycan acquired substitutions of critical amino acids in the V3 region rather than losing the N332 glycosylation site. One of these resistant variants, carrying the full complement of gp120 V3 changes, was also resistant to the potent anti-HIV-1 monoclonal neutralizing antibodies PGT121 and 10-1074, both of which are also dependent on the presence of the gp120 N332 glycan.     

Synthesis and methemoglobinemia-inducing properties of analogues of para-aminopropiophenone designed as humane rodenticides

A number of structural analogues of the known toxicant para-aminopropiophenone (PAPP) have been prepared and evaluated for their capacity to induce methemoglobinemia—with a view to their possible application as humane pest control agents. It was found that an optimal lipophilicity for the formation of methemoglobin (metHb) in vitro existed for alkyl analogues of PAPP (aminophenones 1–20; compound 6 metHb% = 74.1 ± 2). Besides lipophilicity, this structural sub-class suggested there were certain structural requirements for activity, with both branched (10–16) and cyclic (17–20) alkyl analogues exhibiting inferior in vitro metHb induction. Of the four candidates (compounds 4, 6, 13 and 23) evaluated in vivo, 4 exhibited the greatest toxicity. In parallel, aminophenone bioisosteres, including oximes 30–32, sulfoxide 33, sulfone 34 and sulfonamides 35–36, were found to be inferior metHb inducers to lead ketone 4. Closer examination of Hammett substituent constants suggests that a particular combination of the field and resonance parameters may be significant with respect to the redox mechanisms behind PAPPs metHb toxicity.     

Foreword: bacterial homologues of eukaryotic membrane proteins

Abstract

Human lipocalin-1 interacting membrane receptor (LIMR) was the first lipocalin receptor to be identified, as a specific receptor for lipocalin-1 (Lcn1). Subsequently LIMR has been reported to interact with other ligands as well, notably with the bovine lipocalin β-lactoglobulin (BLG) and with the unrelated secretoglobin uteroglobin (UG). To study the ligand-binding behaviour of this prototypic lipocalin receptor in more detail, a system was developed for the recombinant expression of LIMR in Drosophila Schneider 2 (S2) cells, and for the subsequent solubilization and purification of the protein. The receptor forms dimers or larger oligomers when solubilized in n-dodecyl β-D-maltoside (DDM). The full-length, functional receptor was captured onto a surface plasmon resonance (SPR) chip via an α-V5 antibody, and the binding of various potential ligands was followed in time. In this way, LIMR was shown to be highly specific for Lcn1, binding the lipocalin with low micromolar to high nanomolar affinity. No interactions with any of the other putative ligands could be detected, raising doubts about the physiological relevance of the reported binding of BLG and UG to the receptor.     

Assessment of the potential iridology for diagnosing kidney disease using wavelet analysis and neural networks

Alternative or complementary medicine emphasizes therapies that are claimed to improve quality of life, prevent disease, and address conditions that conventional medicine has limited success in curing. There are many techniques which are prevalent in many countries and these can cause harm if not scientifically evaluated. The objective of this paper is to validate the use of iridology to diagnose kidney abnormalities. Two subject groups were evaluated: one was 168 subjects free from kidney disease and the other was 172 subjects with chronic renal failure. The procedure to acquire, process and classify the iris images was designed in such a way that avoids any dependency on the iridologists by using wavelet analysis and Adaptive Neuro-Fuzzy Inference System. The results show a correct classification for both subjects with kidney problems and normal subjects of 82% and 93%, respectively. The proposed technique conducted on a systemic disease with ocular manifestations showed encouraging results. However, it is necessary to perform extensive studies with diseases that do not have ocular manifestations according to conventional medicine in order to validate iridology as a valid scientific technique.     

Measuring Hordein (Gluten) in Beer – A Comparison of ELISA and Mass Spectrometry

Background

Subjects suffering from coeliac disease, gluten allergy/intolerance must adopt a lifelong avoidance of gluten. Beer contains trace levels of hordeins (gluten) which are too high to be safely consumed by most coeliacs. Accurate measurement of trace hordeins by ELISA is problematic.

Methods

We have compared hordein levels in sixty beers, by sandwich ELISA, with the level determined using multiple reaction monitoring mass spectrometry (MRM-MS).

Results

Hordein levels measured by ELISA varied by four orders of magnitude, from zero (for known gluten-free beers) to 47,000 µg/mL (ppm; for a wheat-based beer). Half the commercial gluten-free beers were free of hordein by MS and ELISA. Two gluten-free and two low-gluten beers had zero ELISA readings, but contained significant hordein levels (p<0.05), or near average (60–140%) hordein levels, by MS, respectively. Six beers gave false negatives, with zero ELISA readings but near average hordein content by MS. Approximately 20% of commercial beers had ELISA readings less than 1 ppm, but a near average hordein content by MS. Several barley beers also contained undeclared wheat proteins.

Conclusions

ELISA results did not correlate with the relative content of hordein peptides determined by MS, with all barley based beers containing hordein. We suggest that mass spectrometry is more reliable than ELISA, as ELISA enumerates only the concentration of particular amino-acid epitopes; this may vary between different hordeins and may not be related to the absolute hordein concentration. MS quantification is undertaken using peptides that are specific and unique, enabling the quantification of individual hordein isoforms. This outlines the problem of relying solely on ELISA determination of gluten in beverages such as beer and highlights the need for the development of new sensitive and selective quantitative assay such as MS.     

Chromosome Painting in Three Species of Buteoninae: A Cytogenetic Signature Reinforces the Monophyly of South American Species

Buteoninae (Falconiformes, Accipitridae) consist of the widely distributed genus Buteo, and several closely related species in a group called “sub-buteonine hawks”, such as Buteogallus, Parabuteo, Asturina, Leucopternis and Busarellus, with unsolved phylogenetic relationships. Diploid number ranges between 2n = 66 and 2n = 68. Only one species, L. albicollis had its karyotype analyzed by molecular cytogenetics. The aim of this study was to present chromosomal analysis of three species of Buteoninae: Rupornis magnirostris, Asturina nitida and Buteogallus meridionallis using fluorescence in situ hybridization (FISH) experiments with telomeric and rDNA probes, as well as whole chromosome probes derived from Gallus gallus and Leucopternis albicollis. The three species analyzed herein showed similar karyotypes, with 2n = 68. Telomeric probes showed some interstitial telomeric sequences, which could be resulted by fusion processes occurred in the chromosomal evolution of the group, including the one found in the tassociation GGA1p/GGA6. In fact, this association was observed in all the three species analyzed in this paper, and also in L. albicollis, suggesting that it represents a cytogenetic signature which reinforces the monophyly of Neotropical buteoninae species.     

Predicting 7-Day Survival Using Heart Rate Variability in Hospice Patients with Non-Lung Cancers

Background

A simple and accurate survival prediction tool can facilitate decision making processes for hospice patients with advanced cancers. The objectives of this study were to explore the association of cardiac autonomic functions and survival in patients with advanced cancer and to evaluate the prognostic value of heart rate variability (HRV) in 7-day survival prediction.

Methods

A prospective study was conducted on 138 patients with advanced cancer recruited from the hospice ward of a regional hospital in southern Taiwan. Information on functional status and symptom burden of the patients was recorded. Frequency-domain HRV was obtained for the evaluation of cardiac autonomic functions at admission. The end point of the study was defined as the survival status at day 7 after admission to the hospice ward. Multivariate logistic regression analyses were performed to evaluate the independent associations between HRV indices and survival of 7 days or less.

Results

The median survival time of the patients was 20 days (95% CI, 17–28 days). Results from the multivariate logistic regression analysis indicated that the natural logarithm-transformed high-frequency power (lnHFP) of a value less than 2 (OR = 3.8, p = 0.008) and ECOG performance status of 3 or 4 (OR = 3.4, p = 0.023) were significantly associated with a higher risk of survival of 7 days or less. Receiver operating characteristic (ROC) curve analysis revealed that the area under the curve was 0.71 (95% CI, 0.61–0.81).

Conclusions

In hospice patients with non-lung cancers, an lnHPF value below 2 at hospice admission was significantly associated with survival of 7 days or less. HRV might be used as a non-invasive and objective tool to facilitate medical decision making by improving the accuracy in survival prediction.