Location: Electronic Resource- 

Re-release; Geological Survey of Canada. 1987, 142 pages (25 sheets); 1 diskette/disquette, https://doi.org/10.4095/130284

Re-release; Geological Survey of Canada. 1987, 130 pages (25 sheets); 1 diskette/disquette, https://doi.org/10.4095/130283

Re-release; Department of Indian Affairs & Northern Development; Yukon Government. 1987, 146 pages (25 sheets); 1 diskette/disquette, https://doi.org/10.4095/130285
<a href="https://geoscan.nrcan.gc.ca/images/geoscan/gid_130285.jpg"><img src="https://geoscan.nrcan.gc.ca/images/geoscan/gid_130285.jpg" title=" 1987, 146 pages (25 sheets); 1 diskette/disquette, https://doi.org/10.4095/130285" height="150" border="1" /></a>

Re-release; Geological Survey of Canada. 1989, 60 pages, https://doi.org/10.4095/130703

An industrial chemical used in plastic products has been cropping up in illegal drugs from California to Maine.

Nearly half a century ago, the Environmental Protection Agency used the Toxic Substances Control Act to ban the use and production of polychlorinated biphenyls, or PCBs…

My Chemical Romance (Gerard Way, Ray Toro, Frank Iero, and Mikey Way) will be celebrating The Black Parade this coming summer

Nonphotochemical quenching (NPQ) is a mechanism of regulating light harvesting that protects the photosynthetic apparatus from photodamage by dissipating excess absorbed excitation energy as heat. In higher plants, the major light-harvesting antenna complex (LHCII) of photosystem (PS) II is directly involved in NPQ. The aggregation of LHCII is proposed to be involved in quenching. However, the lack of success in isolating native LHCII aggregates has limited the direct interrogation of this process. The isolation of LHCII in its native state from thylakoid membranes has been problematic because of the use of detergent, which tends to dissociate loosely bound proteins, and the abundance of pigment–protein complexes (e.g. PSI and PSII) embedded in the photosynthetic membrane, which hinders the preparation of aggregated LHCII. Here, we used a novel purification method employing detergent and amphipols to entrap LHCII in its natural states. To enrich the photosynthetic membrane with the major LHCII, we used Arabidopsis thaliana plants lacking the PSII minor antenna complexes (NoM), treated with lincomycin to inhibit the synthesis of PSI and PSII core proteins. Using sucrose density gradients, we succeeded in isolating the trimeric and aggregated forms of LHCII antenna. Violaxanthin- and zeaxanthin-enriched complexes were investigated in dark-adapted, NPQ, and dark recovery states. Zeaxanthin-enriched antenna complexes showed the greatest amount of aggregated LHCII. Notably, the amount of aggregated LHCII decreased upon relaxation of NPQ. Employing this novel preparative method, we obtained a direct evidence for the role of in vivo LHCII aggregation in NPQ.

Ulrich Rothbauer
Feb 1, 2008; 7:282-289
Research

In animals, the response to chronic hypoxia is mediated by prolyl hydroxylases (PHDs) that regulate the levels of hypoxia-inducible transcription factor α (HIFα). PHD homologues exist in other types of eukaryotes and prokaryotes where they act on non HIF substrates. To gain insight into the factors underlying different PHD substrates and properties, we carried out biochemical and biophysical studies on PHD homologues from the cellular slime mold, Dictyostelium discoideum, and the protozoan parasite, Toxoplasma gondii, both lacking HIF. The respective prolyl-hydroxylases (DdPhyA and TgPhyA) catalyze prolyl-hydroxylation of S-phase kinase-associated protein 1 (Skp1), a reaction enabling adaptation to different dioxygen availability. Assays with full-length Skp1 substrates reveal substantial differences in the kinetic properties of DdPhyA and TgPhyA, both with respect to each other and compared with human PHD2; consistent with cellular studies, TgPhyA is more active at low dioxygen concentrations than DdPhyA. TgSkp1 is a DdPhyA substrate and DdSkp1 is a TgPhyA substrate. No cross-reactivity was detected between DdPhyA/TgPhyA substrates and human PHD2. The human Skp1 E147P variant is a DdPhyA and TgPhyA substrate, suggesting some retention of ancestral interactions. Crystallographic analysis of DdPhyA enables comparisons with homologues from humans, Trichoplax adhaerens, and prokaryotes, informing on differences in mobile elements involved in substrate binding and catalysis. In DdPhyA, two mobile loops that enclose substrates in the PHDs are conserved, but the C-terminal helix of the PHDs is strikingly absent. The combined results support the proposal that PHD homologues have evolved kinetic and structural features suited to their specific sensing roles.

Animals can sense the presence of microbes in their tissues and mobilize their own defenses by recognizing and responding to conserved microbial structures (often called microbe-associated molecular patterns (MAMPs)). Successful host defenses may kill the invaders, yet the host animal may fail to restore homeostasis if the stimulatory microbial structures are not silenced. Although mice have many mechanisms for limiting their responses to lipopolysaccharide (LPS), a major Gram-negative bacterial MAMP, a highly conserved host lipase is required to extinguish LPS sensing in tissues and restore homeostasis. We review recent progress in understanding how this enzyme, acyloxyacyl hydrolase (AOAH), transforms LPS from stimulus to inhibitor, reduces tissue injury and death from infection, prevents prolonged post-infection immunosuppression, and keeps stimulatory LPS from entering the bloodstream. We also discuss how AOAH may increase sensitivity to pulmonary allergens. Better appreciation of how host enzymes modify LPS and other MAMPs may help prevent tissue injury and hasten recovery from infection.

RNase J enzymes are metallohydrolases that are involved in RNA maturation and RNA recycling, govern gene expression in bacteria, and catalyze both exonuclease and endonuclease activity. The catalytic activity of RNase J is regulated by multiple mechanisms which include oligomerization, conformational changes to aid substrate recognition, and the metal cofactor at the active site. However, little is known of how RNase J paralogs differ in expression and activity. Here we describe structural and biochemical features of two Staphylococcus epidermidis RNase J paralogs, RNase J1 and RNase J2. RNase J1 is a homodimer with exonuclease activity aided by two metal cofactors at the active site. RNase J2, on the other hand, has endonuclease activity and one metal ion at the active site and is predominantly a monomer. We note that the expression levels of these enzymes vary across Staphylococcal strains. Together, these observations suggest that multiple interacting RNase J paralogs could provide a strategy for functional improvisation utilizing differences in intracellular concentration, quaternary structure, and distinct active site architecture despite overall structural similarity.

Aspergillus terreus is an allergenic fungus, in addition to causing infections in both humans and plants. However, the allergens in this fungus are still unknown, limiting the development of diagnostic and therapeutic strategies. We used a proteomic approach to search for allergens, identifying 16 allergens based on two-dimensional immunoblotting with A. terreus susceptible patient sera. We further characterized triose-phosphate isomerase (Asp t 36), one of the dominant IgE (IgE)-reactive proteins. The gene was cloned and expressed in Escherichia coli. Phylogenetic analysis showed Asp t 36 to be highly conserved with close similarity to the triose-phosphate isomerase protein sequence from Dermatophagoides farinae, an allergenic dust mite. We identified four immunodominant epitopes using synthetic peptides, and mapped them on a homology-based model of the tertiary structure of Asp t 36. Among these, two were found to create a continuous surface patch on the 3D structure, rendering it an IgE-binding hotspot. Biophysical analysis indicated that Asp t 36 shows similar secondary structure content and temperature sensitivity with other reported triose-phosphate isomerase allergens. In vivo studies using a murine model displayed that the recombinant Asp t 36 was able to stimulate airway inflammation, as demonstrated by an influx of eosinophils, goblet cell hyperplasia, elevated serum Igs, and induction of Th2 cytokines. Collectively, our results reveal the immunogenic property of Asp t 36, a major allergen from A. terreus, and define a new fungal allergen more broadly. This allergen could serve as a potent candidate for investigating component resolved diagnosis and immunotherapy.

Pectins are a major dietary nutrient source for the human gut microbiota. The prominent gut microbe Bacteroides thetaiotaomicron was recently shown to encode the founding member (BT1017) of a new family of pectin methylesterases essential for the metabolism of the complex pectin rhamnogalacturonan-II (RG-II). However, biochemical and structural knowledge of this family is lacking. Here, we showed that BT1017 is critical for the metabolism of an RG-II–derived oligosaccharide ΔBT1017oligoB generated by a BT1017 deletion mutant (ΔBT1017) during growth on carbohydrate extract from apple juice. Structural analyses of ΔBT1017oligoB using a combination of enzymatic, mass spectrometric, and NMR approaches revealed that it is a bimethylated nonaoligosaccharide (GlcA-β1,4-(2-O-Me-Xyl-α1,3)-Fuc-α1,4-(GalA-β1,3)-Rha-α1,3-Api-β1,2-(Araf-α1,3)-(GalA-α1,4)-GalA) containing components of the RG-II backbone and its side chains. We showed that the catalytic module of BT1017 adopts an α/β-hydrolase fold, consisting of a central twisted 10-stranded β-sheet sandwiched by several α-helices. This constitutes a new fold for pectin methylesterases, which are predominantly right-handed β-helical proteins. Bioinformatic analyses revealed that the family is dominated by sequences from prominent genera of the human gut microbiota, including Bacteroides and Prevotella. Our re-sults not only highlight the critical role played by this family of enzymes in pectin metabolism but also provide new insights into the molecular basis of the adaptation of B. thetaiotaomicron to the human gut.

Visual Abstract

Daniel J. Geiszler
Dec 1, 2020; 0:TIR120.002216v1-mcp.TIR120.002216
Technological Innovation and Resources

Mutations in the GUCY2D gene coding for the dimeric human retinal membrane guanylyl cyclase (RetGC) isozyme RetGC1 cause various forms of blindness, ranging from rod dysfunction to rod and cone degeneration. We tested how the mutations causing recessive congenital stationary night blindness (CSNB), recessive Leber's congenital amaurosis (LCA1), and dominant cone–rod dystrophy-6 (CORD6) affected RetGC1 activity and regulation by RetGC-activating proteins (GCAPs) and retinal degeneration-3 protein (RD3). CSNB mutations R666W, R761W, and L911F, as well as LCA1 mutations R768W and G982VfsX39, disabled RetGC1 activation by human GCAP1, -2, and -3. The R666W and R761W substitutions compromised binding of GCAP1 with RetGC1 in HEK293 cells. In contrast, G982VfsX39 and L911F RetGC1 retained the ability to bind GCAP1 in cyto but failed to effectively bind RD3. R768W RetGC1 did not bind either GCAP1 or RD3. The co-expression of GUCY2D allelic combinations linked to CSNB did not restore RetGC1 activity in vitro. The CORD6 mutation R838S in the RetGC1 dimerization domain strongly dominated the Ca2+ sensitivity of cyclase regulation by GCAP1 in RetGC1 heterodimer produced by co-expression of WT and the R838S subunits. It required higher Ca2+ concentrations to decelerate GCAP-activated RetGC1 heterodimer—6-fold higher than WT and 2-fold higher than the Ser838-harboring homodimer. The heterodimer was also more resistant than homodimers to inhibition by RD3. The observed biochemical changes can explain the dominant CORD6 blindness and recessive LCA1 blindness, both of which affect rods and cones, but they cannot explain the selective loss of rod function in recessive CSNB.

Open searching has proven to be an effective strategy for identifying both known and unknown modifications in shotgun proteomics experiments. Rather than being limited to a small set of user-specified modifications, open searches identify peptides with any mass shift that may correspond to a single modification or a combination of several modifications. Here we present PTM-Shepherd, a bioinformatics tool that automates characterization of PTM profiles detected in open searches based on attributes such as amino acid localization, fragmentation spectra similarity, retention time shifts, and relative modification rates. PTM-Shepherd can also perform multi-experiment comparisons for studying changes in modification profiles, e.g. in data generated in different laboratories or under different conditions. We demonstrate how PTM-Shepherd improves the analysis of data from formalin-fixed paraffin-embedded samples, detects extreme underalkylation of cysteine in some datasets, discovers an artefactual modification introduced during peptide synthesis, and uncovers site-specific biases in sample preparation artifacts in a multi-center proteomics profiling study.

A recent collaboration among researchers from HUN-REN Wigner Research Centre for Physics in Hungary and the Department of Energy’s Pacific Northwest National Laboratory (PNNL), along with industry collaborators SandboxAQ and […]

The post Collaboration Speeds Complex Chemical Modeling appeared first on HPCwire.

Unlike other birds, which get pigments from their diets, parrots produce their own—but scientists never fully understood the underlying mechanisms, until now

One of the most traditionally time-consuming, labor-intensive processes of apple production is blossom thinning, which involves manually pruning flowers so that remaining blooms can reclaim the plant’s resources to grow better fruit. More recently, the process has shifted to broad chemical spraying, which can have harmful environmental impacts. To assist producers and mitigate environmental harm, the USDA has awarded a three-year, $601,125 grant to a team of Penn State researchers for the development of a robotic precision spraying system.

Attorney General seeks damages, including costs necessary to restore impacted natural resources and funding for State-run public health programs. Attorney General Kathleen Jennings announced that the Department of Justice has filed a lawsuit to hold numerous companies accountable for contaminating Delaware’s natural resources with per- and poly-fluoroalkyl substances (PFAS) traceable to the use and disposal […]

The situation of local fruit vendors has gone from bad to worse after the Thai Pesticide Alert Network (Thai-PAN) released its finding two weeks ago, revealing chemical contamination in popular Shine Muscat grapes.

Title: PFAS 'Forever Chemicals' Linked With Liver Cancer
Category: Health News
Created: 8/10/2022 12:00:00 AM
Last Editorial Review: 8/10/2022 12:00:00 AM

Title: Breakthrough Might Break Down PFAS 'Forever Chemicals'
Category: Health News
Created: 8/19/2022 12:00:00 AM
Last Editorial Review: 8/19/2022 12:00:00 AM

Title: Low Levels of Brain Chemical May Control Appetite
Category: Health News
Created: 8/28/2008 2:00:00 AM
Last Editorial Review: 8/28/2008 12:00:00 AM

Title: Breast-Feeding May Pass Common Chemical to Baby, Study Shows
Category: Health News
Created: 8/21/2015 12:00:00 AM
Last Editorial Review: 8/24/2015 12:00:00 AM

Title: Fewer Cancer-Causing Chemicals in E-Cigs Than Regular Cigarettes: Study
Category: Health News
Created: 8/19/2016 12:00:00 AM
Last Editorial Review: 8/22/2016 12:00:00 AM

Title: Banned PCB Chemicals Still Tied to Autism in U.S. Kids
Category: Health News
Created: 8/23/2016 12:00:00 AM
Last Editorial Review: 8/23/2016 12:00:00 AM

Title: Study Casts Doubt on 'Chemical Imbalance' Theory of Depression
Category: Health News
Created: 8/9/2022 12:00:00 AM
Last Editorial Review: 8/9/2022 12:00:00 AM

The transcription factor (TF) cone-rod homeobox (CRX) is essential for the differentiation and maintenance of photoreceptor cell identity. Several human CRX variants cause degenerative retinopathies, but most are variants of uncertain significance. We performed a deep mutational scan (DMS) of nearly all possible single amino acid substitutions in CRX using a cell-based transcriptional reporter assay, curating a high-confidence list of nearly 2000 variants with altered transcriptional activity. In the structured homeodomain, activity scores closely aligned to a predicted structure and demonstrated position-specific constraints on amino acid substitution. In contrast, the intrinsically disordered transcriptional effector domain displayed a qualitatively different pattern of substitution effects, following compositional constraints without specific residue position requirements in the peptide chain. These compositional constraints were consistent with the acidic exposure model of transcriptional activation. We evaluated the performance of the DMS assay as a clinical variant classification tool using gold-standard classified human variants from ClinVar, identifying pathogenic variants with high specificity and moderate sensitivity. That this performance could be achieved using a synthetic reporter assay in a foreign cell type, even for a highly cell type-specific TF like CRX, suggests that this approach shows promise for DMS of other TFs that function in cell types that are not easily accessible. Together, the results of the CRX DMS identify molecular features of the CRX effector domain and demonstrate utility for integration into the clinical variant classification pipeline.

In Canada and across the globe, access to PSMA PET/CT is limited and expensive. For patients with biochemical recurrence (BCR) after treatment for prostate cancer, novel strategies are needed to better stratify patients who may or may not benefit from a PSMA PET scan. The role of the free-to-total prostate-specific antigen (PSA) ratio (FPSAR) in posttreatment prostate cancer, specifically in the PSMA PET/CT era, remains unknown. Our aim in this study was to determine the association of FPSAR in patients referred for ¹⁸F-DCFPyL PSMA PET/CT in the BCR setting and assess the correlation between FPSAR and ¹⁸F-DCFPyL PSMA PET/CT positivity (local recurrence or distant metastases). Methods: This prospective study included 137 patients who were referred for ¹⁸F-DCFPyL PSMA PET/CT and had BCR with a total PSA of less than 1 ng/mL after radical prostatectomy (RP) (including adjuvant or salvage radiotherapy). Blood samples were collected on the day of ¹⁸F-DCFPyL PSMA PET/CT. FPSAR was categorized as less than 0.10 or as 0.10 or more. A positive ¹⁸F-DCFPyL PSMA PET/CT scan was defined by a PROMISE classification lesion score of 2 or 3, irrespective of the site of increased tracer uptake (e.g., prostate, pelvic nodes, bone, or viscera). Results: Overall, 137 blood samples of patients with BCR after RP were analyzed to calculate FPSAR. The median age at ¹⁸F-DCFPyL PSMA PET/CT was 68.6 y (interquartile range, 63.0–72.4 y), and the median PSA at ¹⁸F-DCFPyL PSMA PET/CT was 0.3 ng/mL (interquartile range, 0.3–0.6 ng/mL). Eighty-six patients (62.8%) had an FPSAR of less than 0.10, whereas 51 patients (37.2%) had an FPSAR of 0.10 or more. An FPSAR of 0.10 or more was identified as an independent predictor of a positive ¹⁸F-DCFPyL PSMA PET/CT scan, with an odds ratio of 6.99 (95% CI, 2.96–16.51; P < 0.001). Conclusion: An FPSAR of 0.10 or more after RP independently correlated with increased odds of a positive ¹⁸F-DCFPyL PSMA PET/CT scan among BCR post-RP patients. These findings may offer an inexpensive method by which to triage access to ¹⁸F-DCFPyL PSMA PET/CT in jurisdictions where availability is not replete.

Congested Kelley goes HONK! Chris runs over old people in GTA while distracting Anna Marie with Octopath. RPGamer tip of the week: If your game has more than 12 currencies, it's main stream.

The post RPG Cast – Episode 643: “Kinky Chemical Engineer” appeared first on RPGamer.

The Cassini mission’s samples from Saturn’s moon Enceladus have signs of various organic molecules that could be among the ingredients needed for life to get started

Scientists in Australia are boosting the country's dwindling freshwater crocodile numbers by getting the animals to stop eating a poisonous toad.

Throughout the fall, unusual white blobs have been washing ashore on beaches in eastern Newfoundland. A Memorial University chemist says the substance is a type of pollution that shouldn't have been in the ocean in the first place.

My Chemical Romance teased a new project on social media. The Welcome to the Black Parade rockers — who broke up in 2013 before releasing new song The Foundations of Decay nine years later — have largely kept things quiet since their reunion tour ended in March 2023, besides a headline slot at When We Were Young Festival last month. On Monday (Nov 11), the band's official Instagram shared an image of a hazy skyline and confetti alongside Russian letters which translate to "TPK". The cryptic post was captioned: "If you could be anything, what would you be?" https://www.instagram.com/p/DCPw84izQkN/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA== While there are no further hints about the message and what it could mean, fans have suggested it may refer to MCR's scrapped record The Paper Kingdom, which was ditched in 2013 and would have been their fifth album.

A new peer-reviewed study published today in the journal Environmental Health Perspectives reveals that per- and polyfluoroalkyl substances (PFAS), often

A team of researchers has uncovered nearly 200 potential breast carcinogens in food packaging materials such as plastics, paper, and cardboard, emphasizing

A common ingredient in plastic may cause breaks in DNA strands, leading to egg cells with an abnormal number of chromosomes in roundworms, reveals a new

Middle-aged women with higher blood concentrations of common synthetic chemicals called per- and polyfluoroalkyl substances (PFAS), also called "forever

President's Cancer Panel Calls for Fundamental Shift in Chemicals Policy

U.S. exports of ethane and ethane-based petrochemicals reached an all-time high of 21.6 million metric tons (MMmt) in 2023, up 135% since the United States began exporting ethane in 2014 and 17% more than in 2022, according to data from the U.S. Census Bureau. The rapid expansion of U.S. ethane and ethane-based petrochemical exports has been fueled by the growth in domestic ethane production, which has increased with the country's natural gas production and the buildout of export and production infrastructure.

Bivas Pattanayak, J. :-

1. The instant execution case has been filed by the plaintiff-decree holder against the defendant-judgment debtor for execution of a decree dated 24th March, 2021 for a sum of Rs.12,54,607.68/-.

2. In its affidavit in support of tabular statement the decree holder contends that the judgement-debtor holds immovable property namely an office at Golpark Co-operative Housing Society, Flat no. 13/B2, 4th Floor, 49C, Govindapur Road, Lake Gardens (near Jodhpur Market), Kolkata-

2

700068 and operates bank account at UCO Bank, Park Circus Branch, Kolkata-700014.

3. The judgement debtor through its partner filed its affidavit of assets who contends that he possesses the above mentioned flat and the bank account.

Every day, we drink water, eat food, grab a quick coffee, hop in the shower, or pick up our phones without thinking twice. They're just part of our daily routine. But what if some of these daily habits are silently affecting