Publications by authors named "David Ott"

Movement performance of insects is an important measure of physiological fitness and is likely affected by novel stressors associated with global change. Reduced fitness can lead to smaller foraging areas and thus to decreasing abundance, diversity and nutritional quality, which could weaken insect populations and contribute to global insect decline. Here, we combined two different methods: An experimental semi-field design applying treatments in outdoor flight cages and a follow-up experiment conducted in the laboratory, in which different parameters of movement performance, such as (a) velocity, (b) duration and (c) distance of an insect's flight can be quantified.

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The ratio of predator-to-prey biomass is a key element of trophic structure that is typically investigated from a food chain perspective, ignoring channels of energy transfer (e.g. omnivory) that may govern community structure.

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Despite intensive research on species dissimilarity patterns across communities (i.e. β-diversity), we still know little about their implications for variation in food-web structures.

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Forest soil and litter is inhabited by a diverse community of animals, which directly and indirectly rely on dead organic matter as habitat and food resource. However, community composition may be driven by biotic or abiotic forces, and these vary with changes in habitat structure and resource supply associated with forest land use. To evaluate these changes, we compiled comprehensive data on the species composition of soil animal communities and environmental factors in forest types varying in land-use intensity in each of three regions in Germany, i.

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Nutrition is the single most important factor for individual's growth and reproduction. Consequently, the inability to reach the nutritional optimum imposes severe consequences for animal fitness. Yet, under natural conditions, organisms may face a mixture of stressors that can modulate the effects of nutritional asymmetry.

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Widespread application of synthetic pesticides and loss of plant diversity are regarded as significant drivers of current global change. The effects of such phenomena on insect performance have been extensively studied separately, yet the interactions of these two drivers have been poorly explored. Here, we subjected the polyphagous grasshopper Pseudochorthippus parallelus (Zetterstedt, 1821) to a full-lifecycle field experiment with 50 cages containing experimental plant communities differing in grass species richness (2 vs.

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Objectives: Del Nido cardioplegia (DNC) has been shown to be safe in adults with normal coronary arteries who are undergoing valve surgery. This study compared the effects of DNC versus traditional blood-based cardioplegia on postoperative complications in patients who underwent coronary artery bypass grafting (CABG).

Methods: A retrospective analysis was performed on 863 patients who underwent CABG with DNC (n = 420) or control cardioplegia (CC) (n = 443) between 2014 and 2017.

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doptive ell ransfer (ACT) is a powerful experimental approach to directly study T-cell-mediated immunity In the rhesus macaque AIDS virus model, infusing simian immunodeficiency virus (SIV)-infected animals with CD8 T cells engineered to express anti-SIV T-cell receptor specificities enables direct experimentation to better understand antiviral T-cell immunity Limiting factors in ACT experiments include suboptimal trafficking to, and poor persistence in, the secondary lymphoid tissues targeted by AIDS viruses. Previously, we redirected CD8 T cells to B-cell follicles by ectopic expression of the CXCR5 homing protein. Here, we modify peripheral blood mononuclear cell (PBMC)-derived CD8 T cells to express the CCR9 chemokine receptor, which induces preferential homing of the engineered cells to the small intestine, a site of intense early AIDS virus replication and pathology in rhesus macaques.

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Agricultural landscapes are globally dominated by monocultures under intensive management. This is one of the main reasons for biodiversity loss and insect population decline in many regions all over the world. Agroecosystem biodiversity in these areas can be enhanced by cropping system diversification, such as crop rotations.

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The late (L) domain sequence used by mouse mammary tumor virus (MMTV) remains undefined. Similar to other L domain-containing proteins, MMTV p8 and p14 proteins are monoubiquitinated, suggesting L domain function. Site-directed mutagenesis of p8, PLPPV, and p14, PLPPL, sequences in MMTV Gag revealed a requirement only for the PLPPV sequence in virion release in a position-dependent manner.

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Article Synopsis
  • Predator-prey interactions in ecosystems create complex food webs with a universal trend of larger predators compared to their prey, which helps stabilize communities.
  • The study developed predator-trait models to predict body-mass ratios from a comprehensive database of 290 food webs across various ecosystems.
  • It was found that specific predator traits, such as size and movement type, significantly influence the body-size relationships, aiding in understanding and managing ecosystem stability.
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For HIV to become infectious, any new virion produced from an infected cell must undergo a maturation process that involves the assembly of viral polyproteins Gag and Gag-Pol at the membrane surface. The self-assembly of these viral proteins drives formation of a new viral particle as well as the activation of HIV protease, which is needed to cleave the polyproteins so that the final core structure of the virus will properly form. Molecules that interfere with HIV maturation will prevent any new virions from infecting additional cells.

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Imaging techniques are a cornerstone of contemporary biology. Over the last decades, advances in microscale imaging techniques have allowed fascinating new insights into cell and tissue morphology and internal anatomy of organisms across kingdoms. However, most studies so far provided snapshots of given reference taxa, describing organs and tissues under "idealized" conditions.

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Right ventricular (RV) myxomas are extremely rare, but may have dreadful clinical sequelae including pulmonary embolism (PE). We present a case of a patient who had an RV myxoma that was attached to the tricuspid valve, and therefore could not be resected completely during surgery, and remnants of the tumor were seen on transthoracic echocardiogram during post-operative follow-up. Five months after surgery, the patient had PE, which could be due to tumor emboli or thromboemboli.

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Prior studies of T-cell responses to KSHV have included relatively few participants and focused on relatively few KSHV antigens. To provide a more comprehensive analysis, we investigated T-cell responses to the whole KSHV proteome using IFN-γ ELISpot. Using ∼7,500 overlapping 15mer peptides we generated one to three peptide pools for each of the 82 KSHV ORFs.

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Alkaptonuric ochronosis is a rare cause of aortic valve stenosis. We report the case of a 61-year-old female patient with alkaptonuria who presented to our institute with the clinical picture of severe aortic valve stenosis, which was confirmed by transthoracic echocardiography. On aortotomy, she was noted to have an impressive black discoloration of ascending aorta and the aortic root complex involving the aortic valve leaflets.

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Living organisms are constrained by both resource quantity and quality. Ecological stoichiometry offers important insights into how the elemental composition of resources affects their consumers. If resource quality decreases, consumers can respond by shifting their body stoichiometry, avoiding low-quality resources, or up-regulating feeding rates to maintain the supply of required elements while excreting excess carbon (i.

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Article Synopsis
  • High biodiversity and biomass in soil communities are essential for the decomposition of low-quality leaf litter in ecosystems like tropical forests.
  • The study analyzed how factors like leaf litter quality, litter mass, plant species richness, and soil pH influence the richness and biomass of different consumer groups among macro-invertebrates in Indonesian tropical forests and agricultural areas.
  • Findings highlighted that litter mass was the strongest predictor of both species richness and biomass, while resource quality more significantly affected species richness compared to overall biomass.
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HIV and SIV infection dynamics are commonly investigated by measuring plasma viral loads. However, this total viral load value represents the sum of many individual infection events, which are difficult to independently track using conventional sequencing approaches. To overcome this challenge, we generated a genetically tagged virus stock (SIVmac239M) with a 34-base genetic barcode inserted between the vpx and vpr accessory genes of the infectious molecular clone SIVmac239.

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Follicular helper CD4 T cells, T, residing in B-cell follicles within secondary lymphoid tissues, are readily infected by AIDS viruses and are a major source of persistent virus despite relative control of viral replication. This persistence is due at least in part to a relative exclusion of effective antiviral CD8 T cells from B-cell follicles. To determine whether CD8 T cells could be engineered to enter B-cell follicles, we genetically modified unselected CD8 T cells to express CXC chemokine receptor 5 (CXCR5), the chemokine receptor implicated in cellular entry into B-cell follicles.

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Celiac artery aneurysms are rare and typically warrant surgical treatment. Atherosclerosis is their chief cause. Symptomatic patients usually present with abdominal pain.

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Article Synopsis
  • - The study investigates how cell-mediated immunity affects the establishment of AIDS virus infections, particularly focusing on the role of antiviral T cells during early infection phases.
  • - Researchers transferred engineered T cells with specific anti-SIV activity to rhesus macaques shortly after SIV exposure, and results showed that the treated animals transmitted fewer viral genotypes compared to controls.
  • - The findings suggest that a robust T-cell response, especially if established prior to infection, can significantly reduce viral transmission and might have implications for vaccine development in preventing AIDS virus infections in humans.
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Giant coronary artery aneurysm associated with a coronary-cameral fistula is an uncommon condition. Such aneurysms are usually associated with other cardiac diseases, such as coronary atherosclerosis, and therefore might augment myocardial ischemia in adults. The main indications for surgical intervention are severe coexisting coronary artery disease, evidence of embolization, and aneurysmal enlargement or rupture.

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