Publications by authors named "Klassen L"

Article Synopsis
  • The common marmoset has become increasingly popular in neuroscience research over the past 20 years, especially for studying human brain diseases, but marmoset-specific research tools are often limited and must be created within labs.
  • A team has designed and tested various imaging and measurement techniques for studying marmosets, including MRI, PET, CT, and electrophysiology, and has made these designs publicly accessible to help ease the burden on researchers.
  • They provide numerous computer-aided design (CAD) files, software, and resources, including tools for neuroimaging and experimental stimuli, through the Marmoset Brain Connectome website to support further advancements in marmoset neuroscience.
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Background: Inulin and inulin-derived fructooligosaccharides (FOS) are well-known prebiotics for use in companion animals and livestock. The mechanisms by which FOS contribute to health has not been fully established. Further, the fine chemistry of fructan structures from diverse sources, such as graminan-type fructans found in cereal crops, has not been fully elucidated.

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Sialic acids are commonly found on the terminal ends of biologically important carbohydrates, including intestinal mucin O-linked glycans. Pathogens such as Clostridium perfringens, the causative agent of necrotic enteritis in poultry and humans, have the ability to degrade host mucins and colonize the mucus layer, which involves removal of the terminal sialic acid by carbohydrate-active enzymes (CAZymes). Here, we present the structural and biochemical characterization of the GH33 catalytic domains of the three sialidases of C.

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Article Synopsis
  • - Horses transformed human mobility, but the timeline of their domestication and integration as transport is debated, with new genetic data being used to clarify this history.
  • - Analysis of 475 ancient horse genomes indicates that modern domestic horses were shaped by human intervention around 2200 BCE, after a domestication bottleneck began around 2700 BCE, leading to a significant expansion across Eurasia.
  • - Evidence also suggests that there was early horse husbandry in central Asia at Botai around 3500 BCE, prior to the establishment of contemporary horse bloodlines, challenging the notion of large herds being linked to migrations around 3000 BCE.
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The analysis of the DNA entrapped in ancient shells of molluscs has the potential to shed light on the evolution and ecology of this very diverse phylum. Ancient genomics could help reconstruct the responses of molluscs to past climate change, pollution, and human subsistence practices at unprecedented temporal resolutions. Applications are however still in their infancy, partly due to our limited knowledge of DNA preservation in calcium carbonate shells and the need for optimized methods for responsible genomic data generation.

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We evaluated the in vitro effects of lyophilization for 2 vesicular stomatitis virus-based vaccines by using 3 stabilizing formulations and demonstrated protective immunity of lyophilized/reconstituted vaccine in guinea pigs. Lyophilization increased stability of the vaccines, but specific vesicular stomatitis virus-based vaccines will each require extensive analysis to optimize stabilizing formulations.

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Multiple sclerosis (MS) is a neuro-inflammatory and neurodegenerative disease that is most prevalent in Northern Europe. Although it is known that inherited risk for MS is located within or in close proximity to immune-related genes, it is unknown when, where and how this genetic risk originated. Here, by using a large ancient genome dataset from the Mesolithic period to the Bronze Age, along with new Medieval and post-Medieval genomes, we show that the genetic risk for MS rose among pastoralists from the Pontic steppe and was brought into Europe by the Yamnaya-related migration approximately 5,000 years ago.

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Article Synopsis
  • The study analyzes 317 ancient genomes from Mesolithic and Neolithic periods across northern and western Eurasia to understand human migration impacts during the Holocene.* -
  • Findings show a significant genetic divide between eastern and western populations, with the west experiencing major gene replacement due to the introduction of farming, while the east maintained its hunter-gatherer ancestry longer.* -
  • The Yamnaya culture, which emerged around 5,000 BP, played a crucial role in spreading ancestry across western Eurasia, leading to significant genetic changes in European populations.*
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Major migration events in Holocene Eurasia have been characterized genetically at broad regional scales. However, insights into the population dynamics in the contact zones are hampered by a lack of ancient genomic data sampled at high spatiotemporal resolution. Here, to address this, we analysed shotgun-sequenced genomes from 100 skeletons spanning 7,300 years of the Mesolithic period, Neolithic period and Early Bronze Age in Denmark and integrated these with proxies for diet (C and N content), mobility (Sr/Sr ratio) and vegetation cover (pollen).

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Carbohydrates are chemically and structurally diverse biomolecules, serving numerous and varied roles in agricultural ecosystems. Crops and horticulture products are inherent sources of carbohydrates that are consumed by humans and non-human animals alike; however carbohydrates are also present in other agricultural materials, such as soil and compost, human and animal tissues, milk and dairy products, and honey. The biosynthesis, modification, and flow of carbohydrates within and between agricultural ecosystems is intimately related with microbial communities that colonize and thrive within these environments.

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Fluorescently labeled polysaccharides enable the visualization of carbohydrate-bacterial interactions and the quantification of carbohydrate hydrolysis rates in cultures and complex communities. Here, we present the method of generating polysaccharides conjugated to the fluorescent molecule, fluoresceinamine. Further, we describe the protocol of incubating these probes in bacterial cultures and complex environmental microbial communities, visualizing bacterial-probe interactions using fluorescence microscopy, and quantifying these interactions using flow cytometry.

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Nigeria experiences annual outbreaks of Lassa fever (LF) with high case numbers. At least three clades of Lassa virus (LASV) have been documented in Nigeria, though recent outbreaks are most often associated with clade II or clade III viruses. Using a recently isolated clade III LASV from a case of LF in Nigeria in 2018, we developed and characterized a guinea pig adapted virus capable of causing lethal disease in commercially available Hartley guinea pigs.

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Rapid dietary changes, such as switching from high-forage to high-grain diets, can modify the rumen microbiome and initiate gastrointestinal distress, such as bloating. In such cases, feed additives, including prebiotics and live microbials, can be used to mitigate these negative consequences. Bio-Mos® is a carbohydrate-based prebiotic derived from yeast cells that is reported to increase livestock performance.

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The global spread of monkeypox virus has raised concerns over the establishment of novel enzootic reservoirs in expanded geographic regions. We demonstrate that although deer mice are permissive to experimental infection with clade I and II monkeypox viruses, the infection is short-lived and has limited capability for active transmission.

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Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity and impulsivity. A dearth of studies have investigated psychosexuality in this population, often with few (predominantly male) participants. We recruited individuals with and without ADHD via an anonymous online survey distributed electronically by ADHD support organizations and social media.

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The recent emergence of the monkeypox virus (MPXV) in non-endemic countries has been designated a Public Health Emergency of International Concern by the World Health Organization. There are currently no approved treatments for MPXV infection in the United States or Canada. The antiviral drug tecovirimat (commonly called TPOXX), previously approved for smallpox treatment, is currently being deployed for treatment of MPXV infections where available based on previously accrued data.

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A circulating tumor cell (CTC) is a type of cell that is shed from solid tumors, swept away in the bloodstream or lymphatic system, and has the potential to cause tumorigenesis at a secondary location. Here we describe an early pupal leg system to study CTCs and to compare the CTCs described in this work to those previously studied We quantified cellular parameters such as the number, size, and shape of CTCs, and our findings are consistent with previous studies. Thus, live imaging of CTCs in model organisms can complement and validate previous work in this field and can be an initial step when deciphering how CTCs behave in humans during metastasis.

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Article Synopsis
  • Microbial glycan degradation plays a crucial role in global carbon cycling, with the marine bacterium Salegentibacter sp. Hel_I_6 showing potential in breaking down α-mannan, a component sourced from fungi.
  • The bacterium's gene cluster includes an endo-α-1,6-mannanase enzyme (ShGH76) that functions similarly to enzymes found in human gut bacteria, indicating a shared ability to digest fungal material.
  • Research findings show that ShGH76 has unique structural characteristics and demonstrates strong activity on α-mannan substrates, hinting at the presence of previously unidentified fungal α-1,6-mannans in marine ecosystems, particularly during periods of microalgae blooms.
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Native porphyran is a hybrid of porphryan and agarose. As a common element of edible seaweed, this algal galactan is a frequent component of the human diet. Bacterial members of the human gut microbiota have acquired polysaccharide utilization loci (PULs) that enable the metabolism of porphyran or agarose.

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The common marmoset (Callithrix jacchus) is quickly gaining traction as a premier neuroscientific model. However, considerable progress is still needed in understanding the functional and structural organization of the marmoset brain to rival that documented in longstanding preclinical model species, like mice, rats, and Old World primates. To accelerate such progress, we present the Marmoset Functional Brain Connectivity Resource (marmosetbrainconnectome.

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Intravenous (IV) ketamine is increasingly used off-label at subanesthetic doses for its rapid antidepressant effect, and intranasal (IN) esketamine has been recently approved in several countries for treating depression. The clinical utility of these treatments is limited by a paucity of publicly funded IV ketamine and IN esketamine programs and cost barriers to private treatment programs, as well as the drug cost for IN esketamine itself, which makes generic ketamine alternatives an attractive option. Though evidence is limited, use of non-parenteral racemic ketamine formulations (oral, sublingual, and IN) may offer more realistic access in less rigidly supervised settings, both for acute and maintenance treatment in select cases.

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There is a knowledge gap regarding the factors that impede the ruminal digestion of plant cell walls or if rumen microbiota possess the functional activities to overcome these constraints. Innovative experimental methods were adopted to provide a high-resolution understanding of plant cell wall chemistries, identify higher-order structures that resist microbial digestion, and determine how they interact with the functional activities of the rumen microbiota. We characterized the total tract indigestible residue (TTIR) from cattle fed a low-quality straw diet using two comparative glycomic approaches: ELISA-based glycome profiling and total cell wall glycosidic linkage analysis.

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