Why sloths defecate on the ground: rejection of the mutualistic model

Introduction: Sloths are arboreal mammals that defecate on the ground, increasing the risk of predation. There are several hypotheses that try to explain why they undergo this risk. Objective: To critically review all the hypotheses and to propose a new hypothesis that is compatible with all known data. Methods: I verified the assumptions and implications of five hypotheses against the literature available February, 2021. Results: Previous hypotheses either lack reliable supporting data, or are contradicted by published data. Here I propose that defecation on the ground is an ancestral behavior that persists in all sloth species because there has not been enough natural selection against it. Conclusions: Current knowledge of sloth biology is compatible with the hypothesis that there has not been enough selective pressure for sloths to abandon defecation on the ground.

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Efforts to emulate human milk oligosaccharides

British Journal Of Nutrition ◽

10.1017/s0007114507838062 ◽

2007 ◽

Vol 98 (S1) ◽

pp. S74-S79 ◽

Cited By ~ 21

Author(s):

Rosa María Espinosa ◽

Martha Taméz ◽

Pedro Prieto

Keyword(s):

Breast Milk ◽

Human Milk ◽

Current Knowledge ◽

Biological Effects ◽

Historical Context ◽

Published Data ◽

Human Milk Oligosaccharides ◽

Milk Oligosaccharides ◽

Fast Analysis ◽

Chemical Structures

Research on human milk oligosaccharides (HMO) began with the characterisation of their chemical structures and is now focused on the elucidation of their biological roles. Previously, biological effects could only be investigated with fractions or structures isolated from breast milk; consequently, clinical observations were limited to comparisons between outcomes from breast-fed infants and their formula-fed counterparts. In some cases, it was inferred that the observed differences were caused by the presence of HMO in breast milk. Presently, analytical techniques allow for the fast analysis of milk samples, thus providing insights on the inherent variability of specimens. In addition, methods for the synthesis of HMO have provided single structures in sufficient quantities to perform clinical studies with oligosaccharide-supplemented formulae. Furthermore, studies have been conducted with non-mammalian oligosaccharides with the purpose of assessing the suitability of these structures to functionally emulate HMO. Taken together, these developments justify summarising current knowledge on HMO to further discussions on efforts to emulate human milk in regard to its oligosaccharide content. The present account summarises published data and intends to provide an historical context and to illustrate the state of the field.

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Possible influence of anti-vector immunity and SARS-CoV-2 variants on efficacy of ChAdOx1 nCoV-19 vaccine and the proposal of a new pharmacotherapy

10.22541/au.162141142.21655505/v1 ◽

2021 ◽

Author(s):

Loris Zamal ◽

Marco Rocchi

Keyword(s):

Immune Response ◽

Longitudinal Studies ◽

Selective Pressure ◽

Response Prediction ◽

Published Data ◽

Zinc Metalloprotease ◽

Preventive Actions ◽

The Moment ◽

The Impact

The present work analyses in detail the published data on ChAdOx1 nCoV-19 vaccine and provides arguments for the involvement of anti-vector immunity and of SARS-CoV-2 variants on the efficacy of ChAdOx1 nCoV-19 vaccine. First, it is suggested that anti-vector immunity takes place as the regimen of homologous vaccination with ChAdOx1 nCoV-19 vaccine is applied and interferes with efficacy of the vaccine when the interval between prime and boost doses is less than three months. Second, longitudinal studies suggest that ChAdOx1 nCoV-19 vaccine provides sub-optimal efficacy against UK variant of SARS-CoV-2, which appears to have an increased transmissibility over the ancestral SARS-CoV-2 among vaccinated people. At the moment, ChAdOx1 nCoV-19 vaccine is able to reduce the severity of symptoms and transmissibility; however, if the vaccinated individuals do not maintain everyday preventive actions, they could turn into potential spreaders, thus accelerating the process of generation of new viral variants due to the selective pressure of immune response. Prediction and possible consequences of the SARS-CoV-2 evolution and repeated anti-SARS-CoV-2 vaccinations are discussed. Since the impact of emerging SARS-CoV-2 variants suggests that vaccines are unlikely to be effective in quickly solving the pandemic crisis, it is highlighted the need to keep searching for new and more efficacious pharmacotherapy for COVID-19, such as those targeting ACE2 and ADAM17 zinc-metalloprotease activities.

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Genetic load and biological changes to extant humans

Journal of Biosocial Science ◽

10.1017/s0021932020000413 ◽

2020 ◽

pp. 1-4

Author(s):

Arthur Saniotis ◽

Maciej Henneberg ◽

Kazhaleh Mohammadi

Keyword(s):

Natural Selection ◽

Current Knowledge ◽

Genetic Load ◽

Differential Fertility ◽

Medical Interventions ◽

Deleterious Alleles ◽

Gradual Process ◽

Genetic Complexity ◽

Sexual Recombination ◽

Improved Sanitation

Abstract Extant humans are currently increasing their genetic load, which is informing present and future human microevolution. This has been a gradual process that has been rising over the last centuries as a consequence of improved sanitation, nutritional improvements, advancements in microbiology and medical interventions, which have relaxed natural selection. Moreover, a reduction in infant and child mortality and changing societal attitudes towards fertility have led to a decrease in total fertility rates (TFRs) since the 19th century. Generally speaking, decreases in differential fertility and mortality have meant that there is less opportunity for natural selection to eliminate deleterious mutations from the human gene pool. It has been argued that the average human may carry ~250–300 mutations that are mostly deleterious, as well as several hundred less-deleterious variants. These deleterious alleles in extant humans mean that our fitness is being constrained. While such alleles are viewed as reducing human fitness, they may also have had an adaptive function in the past, such as assisting in genetic complexity, sexual recombination and diploidy. Saying this, our current knowledge on these fitness compromising alleles is still lacking.

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Male mating success and risk of predation in a wolf spider: a balance between sexual and natural selection?

Journal of Animal Ecology ◽

10.1046/j.1365-2656.1998.00192.x ◽

1998 ◽

Vol 67 (2) ◽

pp. 287-291 ◽

Cited By ~ 81

Author(s):

Janne Kotiaho ◽

Rauno V. Alatalo ◽

Johanna Mappes ◽

Silja Parri ◽

Ana Rivero

Keyword(s):

Natural Selection ◽

Mating Success ◽

Wolf Spider ◽

Male Mating ◽

Male Mating Success ◽

Risk Of Predation

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Adaptive strategies of the candidate probioticE. coliNissle in the mammalian gut

10.1101/364505 ◽

2018 ◽

Cited By ~ 1

Author(s):

Nathan Crook ◽

Aura Ferreiro ◽

Andrew J. Gasparrini ◽

Mitchell Pesesky ◽

Molly K. Gibson ◽

...

Keyword(s):

Natural Selection ◽

Gastrointestinal Tract ◽

Selective Pressure ◽

Adaptive Strategies ◽

Species Competition ◽

E Coli ◽

Genetic Function ◽

Probiotic Strains ◽

Therapeutic Properties ◽

Serum Phenylalanine

SummaryProbiotics are living microorganisms that are increasingly used as gastrointestinal therapeutics by virtue of their innate or engineered genetic function. Unlike abiotic therapeutics, probiotics can replicate in their intended site, subjecting their genomes and therapeutic properties to natural selection. By exposing the candidate probioticE. coliNissle (EcN) to the mouse gastrointestinal tract over several weeks, we uncovered the consequences of gut transit, inter-species competition, antibiotic pressure, and engineered genetic function on the processes under selective pressure during both within-genome and horizontal evolutionary modes. We then show the utility of EcN as a chassis for engineered function by achieving the highest reported reduction in serum phenylalanine levels in a mouse model of phenylketonuria using an engineered probiotic. Collectively, we demonstrate a generalizable pipeline which can be applied to other probiotic strains to better understand their safety and engineering potential.

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Can new immunoassay techniques improve bladder cancer diagnostics With protein biomarkers?

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2020.620687 ◽

2021 ◽

Vol 7 ◽

Author(s):

Yuri M. Shlyapnikov ◽

Ekaterina A. Malakhova ◽

Andrey Z. Vinarov ◽

Andrey A. Zamyatnin ◽

Elena A. Shlyapnikova

Keyword(s):

Experimental Data ◽

Bladder Cancer ◽

Diagnostic Tests ◽

Current Knowledge ◽

Test System ◽

Cancer Diagnostics ◽

Published Data ◽

Protein Biomarkers ◽

Low Concentrations ◽

Highly Sensitive

The search for new diagnostic tests for cancer or ways to improve existing tests is primarily driven by the desire to identify the disease as early as possible. In this report, we summarize the current knowledge of the most promising diagnostic protein bladder cancer (BC) markers reported over the last decade. Unfortunately, analysis of published data suggests that a reliable, highly sensitive biomarker test-system based on ELISA for detecting BC has not yet been developed. The use of more sensitive assays to detect ultra-low concentrations of biomarkers not available for ELISA, could be very beneficial. Based on the literature and pilot experimental data, we conclude that a highly sensitive immunoassay using microarrays and magnetic labels, could be an effective and cheap technique suitable for the detection of diagnostically relevant BC biomarkers.

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Diagnosis and Clinical Management of Neuroendocrine Tumor of the Breast: Report of Six Cases and Systematic Review of Existing Literature

Annals of Clinical Oncology ◽

10.31487/j.aco.2020.01.02 ◽

2020 ◽

pp. 1-14

Author(s):

Corrado Tinterri ◽

Alberto Bottini ◽

Alessandro De Luca ◽

Andrea Sagona ◽

Corrado Tinterri ◽

...

Keyword(s):

Breast Cancer ◽

Systematic Review ◽

Neuroendocrine Tumor ◽

Neuroendocrine Carcinoma ◽

Clinical Management ◽

Current Knowledge ◽

Neuroendocrine Differentiation ◽

Neuroendocrine Neoplasm ◽

Published Data ◽

Tumor Biopsy

Introduction: Neuroendocrine neoplasm of the breast (bNENs) are considered a rare disease, even if in WHO data they represent about 2-5 % of all breast cancer. The last WHO classification includes: welldifferentiated neuroendocrine tumor (bNET), neuroendocrine carcinoma (NEC) and invasive carcinoma with neuroendocrine differentiation. The current knowledge on clinical management of bNENs is poor and patients are usually treated according to non-endocrine tumor components guidelines. Materials and Methods: We presented our experience of six cases of bNENs. Moreover, we conducted a systematic review of published data on diagnosis, treatment and outcome of this kind of tumors. Results: bNENS usually presented as palpable breast masses, classically appearing as irregular hypoechoic lesions at US examination and as hyperdense masses at mammography. Usually pre-operative tumor biopsy is not able to recognize the neuroendocrine components and the final diagnosis is performed only on definitive histopathological assessment. The most frequent subtype seems to be neuroendocrine carcinoma and synaptophysin is positive in most specimens. Treatment strategies, including surgical treatment, radiotherapy and medical treatment are nowadays based on current non-endocrine breast cancer guidelines, independently from neuroendocrine components, even if some studies have proposed the use of somatostatin analogues for bNET and cisplatin-etoposide for NEC. Prognosis of all bNENs, especially of poorly differentiated neoplasia, seems worse compared to non-neuroendocrine breast cancer and stage and morphology seem the best predictor of tumor outcome. Conclusions: We provide an algorithm for clinical management of bNETs, basing on available data. More studies are necessary for confirming the best treatment strategy for these patients, in order to improve clinical outcome

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HEREDITARY ENDOCRINE TUMOURS: CURRENT STATE-OF-THE-ART AND RESEARCH OPPORTUNITIES: New and future perspectives for parathyroid carcinoma

Endocrine Related Cancer ◽

10.1530/erc-20-0018 ◽

2020 ◽

Vol 27 (8) ◽

pp. T53-T63

Author(s):

Nancy D Perrier ◽

Andrew Arnold ◽

Jessica Costa-Guda ◽

Naifa L Busaidy ◽

Ha Nguyen ◽

...

Keyword(s):

Parathyroid Carcinoma ◽

Literature Search ◽

Expert Panel ◽

Current Knowledge ◽

International Workshop ◽

Steering Committee ◽

Published Data ◽

Extensive Literature ◽

Parathyroid Cancer ◽

Current State

This report summarizes published data on parathyroid cancer, with the inclusion of topics discussed at MEN2019: 16th International Workshop on Multiple Endocrine Neoplasia, 27–29 March 2019, Houston, TX, USA. An expert panel on parathyroid cancer was constituted by the Steering Committee to address key questions in the field. The objectives were to recap open forum discussion of interested parties from multiple disciplines. The expert panel met in a closed session to consult on the data to be highlighted on the evidence-based results and on the future directions. Preceding the Conference, members of the expert panel conducted an extensive literature search. All presentations were based upon the best peer-reviewed information taking into account the historical and current literature. Questions were developed by the expert panel on parathyroid carcinoma. A comprehensive literature search for relevant studies was undertaken. This report represents the expert panel’s synthesis of the conference material placed in a context designed to be relevant to clinicians and those engaged in cutting-edge studies of parathyroid carcinoma. This document not only provides a summary of our current knowledge but also places recent advances in its management into a context that should enhance future advances in our understanding of parathyroid carcinoma.

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A Review of the Current Knowledge of Thermal Stability of Anthocyanins and Approaches to Their Stabilization to Heat

Antioxidants ◽

10.3390/antiox10091337 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1337

Author(s):

Simona Oancea

Keyword(s):

Thermal Stability ◽

Rational Design ◽

Molecular Mechanisms ◽

Current Knowledge ◽

Scientific Progress ◽

Bioactive Molecules ◽

Environmental Stability ◽

Published Data ◽

Thermal Stability Of ◽

Anthocyanin Degradation

Anthocyanins are colored valuable biocompounds, of which extraction increases globally, although functional applications are restrained by their limited environmental stability. Temperature is a critical parameter of food industrial processing that impacts on the food matrix, particularly affecting heat-sensitive compounds such as anthocyanins. Due to the notable scientific progress in the field of thermal stability of anthocyanins, an analytical and synthetic integration of published data is required. This review focuses on the molecular mechanisms and the kinetic parameters of anthocyanin degradation during heating, both in extracts and real food matrices. Several kinetic models (Arrhenius, Eyring, Ball) of anthocyanin degradation were studied. Crude extracts deliver more thermally stable anthocyanins than purified ones. A different anthocyanin behavior pattern within real food products subjected to thermal processing has been observed due to interactions with some nutrients (proteins, polysaccharides). The most recent studies on the stabilization of anthocyanins by linkages to other molecules using classical and innovative methods are summarized. Ensuring appropriate thermal conditions for processing anthocyanin-rich food will allow a rational design for the future development of stable functional products, which retain these bioactive molecules and their functionalities to a great extent.

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Right phenotype, wrong place: predator-induced plasticity is costly in a mismatched environment

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.2347 ◽

2019 ◽

Vol 286 (1916) ◽

pp. 20192347 ◽

Cited By ~ 2

Author(s):

Anne A. Innes-Gold ◽

Nicholas Y. Zuczek ◽

Justin C. Touchon

Keyword(s):

Natural Selection ◽

Survival Benefit ◽

Morphological Changes ◽

Survival Rates ◽

Environmental Cost ◽

Heterogeneous Environment ◽

Trade Off ◽

Risk Of Predation ◽

Dendropsophus Ebraccatus ◽

Wrong Place

Like many animals, tadpoles often produce different, predator-specific phenotypes when exposed to risk of predation. It is generally assumed that such plasticity enhances survival in the presence of the predator and is costly elsewhere, but evidence remains surprisingly scarce. We measured (1) the survival trade-off of opposing phenotypes developed by Dendropsophus ebraccatus tadpoles when exposed to different predators and (2) which specific aspects of morphology drive any potential survival benefit or cost. Tadpoles developed predator-specific phenotypes after being reared with caged fish or dragonfly predators for two weeks. In 24 h predation trials with either a fish or a dragonfly, survival was highest in the groups with their matched predator, and lowest among with those the mismatched predator, with predator-naive controls being relatively intermediate. Then, using a large group of phenotypically variable predator-naive tadpoles, we found that increased survival rates are directly related to the morphological changes that are induced by each predator. This demonstrates that induced phenotypes are indeed adaptive and the product of natural selection. Furthermore, our data provide clear evidence of an environmental cost for phenotypic plasticity in a heterogeneous environment. Such costs are fundamental for understanding the evolution and maintenance of inducible phenotypes.

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