116 results match your criteria longstanding hypotheses


Creation of a universal experimental protocol for the investigation of transfer and persistence of trace evidence: Part 1 - From design to implementation for particulate evidence.

Forensic Sci Int Synerg 2021 29;3:100165. Epub 2021 Aug 29.

Leverhulme Research Centre for Forensic Science, University of Dundee, Dundee, DD1 4HN, UK.

Understanding the transfer and persistence of different types of trace evidence between different donor and receiving surfaces under specific conditions, circumstances and alleged competing defence and prosecution hypotheses is a significant need. Acquiring such a knowledge base enables hypothesis testing to be undertaken more readily and with greater confidence. A longstanding goal has been to develop a unified approach to transfer and persistence studies which are fit for purpose but also scalable. Read More

View Article and Full-Text PDF

Diapause differentially modulates the transcriptomes of fat body and flight muscle in the Colorado potato beetle.

Comp Biochem Physiol Part D Genomics Proteomics 2021 Sep 3;40:100906. Epub 2021 Sep 3.

Department of Biology, University of Western Ontario, 1151 Richmond Street N, London, ON N6A 3K7, Canada. Electronic address:

Many temperate insects, such as the Colorado potato beetle, enter diapause in winter, during which they arrest their development, suppress their metabolic rate and have high stress tolerance. Diapause phenotypes can be transcriptionally regulated, however many studies to date report only whole animal gene expression rather than tissue-specific processes during diapause. We used RNA-seq to measure gene expression in fat body and flight muscle of diapausing and non-diapausing beetles. Read More

View Article and Full-Text PDF
September 2021

Rapid shifts in mitochondrial tRNA import in a plant lineage with extensive mitochondrial tRNA gene loss.

Mol Biol Evol 2021 Aug 26. Epub 2021 Aug 26.

Department of Biology, Colorado State University, Fort Collins, CO, 80523-1878, USA.

In most eukaryotes, transfer RNAs (tRNAs) are one of the very few classes of genes remaining in the mitochondrial genome, but some mitochondria have lost these vestiges of their prokaryotic ancestry. Sequencing of mitogenomes from the flowering plant genus Silene previously revealed a large range in tRNA gene content, suggesting rapid and ongoing gene loss/replacement. Here, we use this system to test longstanding hypotheses about how mitochondrial tRNA genes are replaced by importing nuclear-encoded tRNAs. Read More

View Article and Full-Text PDF

A Novel Conceptual Model for the Dual Role of FF-ATP Synthase in Cell Life and Cell Death.

Authors:
Sunil Nath

Biomol Concepts 2020 Aug 22;11(1):143-152. Epub 2020 Aug 22.

Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi110016, India.

The mitochondrial permeability transition (MPT) has been one of the longstanding enigmas in biology. Its cause is currently at the center of an extensive scientific debate, and several hypotheses on its molecular nature have been put forward. The present view holds that the transition arises from the opening of a high-conductance channel in the energy-transducing membrane, the permeability transition pore (PTP), also called the mitochondrial megachannel or the multiconductance channel (MMC). Read More

View Article and Full-Text PDF

A vertebrate adaptive radiation is assembled from an ancient and disjunct spatiotemporal landscape.

Proc Natl Acad Sci U S A 2021 May;118(20)

Department of Integrative Biology, University of California, Berkeley, CA 94720;

To investigate the origins and stages of vertebrate adaptive radiation, we reconstructed the spatial and temporal histories of adaptive alleles underlying major phenotypic axes of diversification from the genomes of 202 Caribbean pupfishes. On a single Bahamian island, ancient standing variation from disjunct geographic sources was reassembled into new combinations under strong directional selection for adaptation to the novel trophic niches of scale-eating and molluscivory. We found evidence for two longstanding hypotheses of adaptive radiation: hybrid swarm origins and temporal stages of adaptation. Read More

View Article and Full-Text PDF

Scanning the human genome for "signatures" of positive selection: Transformative opportunities and ethical obligations.

Evol Anthropol 2021 Mar 31;30(2):113-121. Epub 2021 Mar 31.

Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania, USA.

The relationship history of evolutionary anthropology and genetics is complex. At best, genetics is a beautifully integrative part of the discipline. Yet this integration has also been fraught, with punctuated, disruptive challenges to dogma, periodic reluctance by some members of the field to embrace results from analyses of genetic data, and occasional over-assertions of genetic definitiveness by geneticists. Read More

View Article and Full-Text PDF

Tracing molecular properties throughout evolution: A chemoinformatic approach.

J Theor Biol 2021 04 26;515:110601. Epub 2021 Jan 26.

Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Buenos Aires, Argentina; Universidad de Buenos Aires, CONICET, Unidad de Microanálisis y Métodos Físicos Aplicados a Química Orgánica (UMYMFOR), Buenos Aires, Argentina. Electronic address:

Evolution of metabolism is a longstanding yet unresolved question, and several hypotheses were proposed to address this complex process from a Darwinian point of view. Modern statistical bioinformatic approaches targeted to the comparative analysis of genomes are being used to detect signatures of natural selection at the gene and population level, as an attempt to understand the origin of primordial metabolism and its expansion. These studies, however, are still mainly centered on genes and the proteins they encode, somehow neglecting the small organic chemicals that support life processes. Read More

View Article and Full-Text PDF

Granick revisited: Synthesizing evolutionary and ecological evidence for the late origin of bacteriochlorophyll via ghost lineages and horizontal gene transfer.

PLoS One 2021 28;16(1):e0239248. Epub 2021 Jan 28.

Department of Plant Biology, University of California, Davis, California, United States of America.

Photosynthesis-both oxygenic and more ancient anoxygenic forms-has fueled the bulk of primary productivity on Earth since it first evolved more than 3.4 billion years ago. However, the early evolutionary history of photosynthesis has been challenging to interpret due to the sparse, scattered distribution of metabolic pathways associated with photosynthesis, long timescales of evolution, and poor sampling of the true environmental diversity of photosynthetic bacteria. Read More

View Article and Full-Text PDF

It is time to drop hydroxychloroquine from our COVID-19 armamentarium.

Med Hypotheses 2020 Nov 17;144:110198. Epub 2020 Aug 17.

Infectious Diseases Section, Department of Medical Specialties, King Fahad Medical City, Riyadh, Saudi Arabia; Division of Infectious Diseases, Mayo Clinic College of Medicine and Science, Rochester, MN, USA; Department of Epidemiology, Mayo Clinic College of Medicine and Science, Rochester, MN, USA; College of Medicine, Al Faisal University, Riyadh, Saudi Arabia. Electronic address:

Chloroquine (CQ) and hydroxychloroquine (HCQ) were among the first drugs repurposed for the treatment of SARS-CoV-2 infection. A few in vitro studies confirmed that both drugs exhibited dose dependent anti-SARS-CoV-2 activities. These observations and the encouraging results from early poorly conducted observational studies created a major hype about the therapeutic potential of these drugs in the treatment of COVID-19 disease. Read More

View Article and Full-Text PDF
November 2020

Identifying Minimal and Meaningful Change in PROMIS for Rheumatoid Arthritis: Use of Multiple Methods and Perspectives.

Arthritis Care Res (Hoboken) 2020 Nov 9. Epub 2020 Nov 9.

Division of Rheumatology, Johns Hopkins University, MFL Center Tower, 5200 Eastern Avenue, Suite 4100, Baltimore, MD, 21224, USA.

Background: Rheumatoid arthritis (RA) is chronic, painful, disabling condition resulting in significant impairments in physical, emotional, and social health. We used different methods and perspectives to evaluate the responsiveness of PROMIS® short forms (SFs) and identify minimal and meaningful score changes.

Methods: Adults with RA enrolled in a multi-site prospective observational cohort completed PROMIS Physical Function, Pain Interference, Fatigue, Participation in Social Roles/Activities SFs, PROMIS-29, and pain, patient global, and rated change in specific symptoms and RA (a little vs. Read More

View Article and Full-Text PDF
November 2020

A Novel Conceptual Model for the Dual Role of FOF1-ATP Synthase in Cell Life and Cell Death.

Authors:
Sunil Nath

Biomol Concepts 2020 Aug;11(1):143-152

Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.

The mitochondrial permeability transition (MPT) has been one of the longstanding enigmas in biology. Its cause is currently at the center of an extensive scientific debate, and several hypotheses on its molecular nature have been put forward. The present view holds that the transition arises from the opening of a high-conductance channel in the energy-transducing membrane, the permeability transition pore (PTP), also called the mitochondrial megachannel or the multiconductance channel (MMC). Read More

View Article and Full-Text PDF

Visual detection and fruit selection by the mantled howler monkey (Alouatta palliata).

Am J Primatol 2020 10 19;82(10):e23186. Epub 2020 Aug 19.

Biología de la Conducta, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, México.

Howler monkeys (platyrrhini) have evolved routine trichromatic color vision independently from catarrhines, which presents an opportunity to test hypotheses concerning the adaptive value of distinguishing reddish from greenish hues. A longstanding hypothesis posits that trichromacy aids in the efficient detection of reddish-ripe fruits, which could be an advantage for the detection of the nutritional content of the fruit, such as sugars. In the present study, we assessed fruit visual conspicuity and selection based on color and sucrose content by wild mantled howler monkeys (Alouatta palliata) on Agaltepec Island, Mexico. Read More

View Article and Full-Text PDF
October 2020

Perineural dextrose injections in the treatment of lower urinary tract symptoms and dyspareunia induced by obturator neuralgia.

Med Hypotheses 2020 Nov 11;144:109991. Epub 2020 Jun 11.

Avenue d'Haouza, Le Mans, France.

Obturator neuralgia is commonly diagnosed and treated in orthopedics. It produces groin pain, sensory alteration in the medial thigh (dysesthesia, sensory loss, or pain), adductor muscle weakness and pain/restriction of hip movements. Basically, the clinical diagnosis of obturator neuralgia is made by producing pain during internal rotation of the hip against resistance ("obturator sign") or by extension and lateral leg movements. Read More

View Article and Full-Text PDF
November 2020

The Enigma of Centriole Loss in the 1182-4 Cell Line.

Cells 2020 05 23;9(5). Epub 2020 May 23.

Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306-4300, USA.

The cell line 1182-4, which constitutively lacks centrioles, was established many years ago from haploid embryos laid by females homozygous for the mutation. This was the first clear example of animal cells regularly dividing in the absence of this organelle. However, the cause of the acentriolar nature of the 1182-4 cell line remained unclear and could not be clearly assigned to a particular genetic event. Read More

View Article and Full-Text PDF

Aligning functional network constraint to evolutionary outcomes.

BMC Evol Biol 2020 05 24;20(1):58. Epub 2020 May 24.

Department of Biological and Marine Sciences, University of Hull, Cottingham Road, Kingston-Upon-Hull, HU6 7RX, UK.

Background: Functional constraint through genomic architecture is suggested to be an important dimension of genome evolution, but quantitative evidence for this idea is rare. In this contribution, existing evidence and discussions on genomic architecture as constraint for convergent evolution, rapid adaptation, and genic adaptation are summarized into alternative, testable hypotheses. Network architecture statistics from protein-protein interaction networks are then used to calculate differences in evolutionary outcomes on the example of genomic evolution in yeast, and the results are used to evaluate statistical support for these longstanding hypotheses. Read More

View Article and Full-Text PDF

Ontologically simple theories do not indicate the true nature of complex biological systems: three test cases.

Authors:
Michael Fry

Hist Philos Life Sci 2020 Apr 28;42(2):17. Epub 2020 Apr 28.

Department of Biochemistry, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, POB 9649, 31096, Bat Galim, Haifa, Israel.

A longstanding philosophical premise perceives simplicity as a desirable attribute of scientific theories. One of several raised justifications for this notion is that simple theories are more likely to indicate the true makeup of natural systems. Qualitatively parsimonious hypotheses and theories keep to a minimum the number of different postulated entities within a system. Read More

View Article and Full-Text PDF

Atrial fibrillation fingerprinting; spotting bio-electrical markers to early recognize atrial fibrillation by the use of a bottom-up approach (AFFIP): Rationale and design.

Clin Cardiol 2020 Jun 18;43(6):546-552. Epub 2020 Apr 18.

Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands.

Background: The exact pathophysiology of atrial fibrillation (AF) remains incompletely understood and treatment of AF is associated with high recurrence rates. Persistence of AF is rooted in the presence of electropathology, defined as complex electrical conduction disorders caused by structural damage of atrial tissue. The atrial fibrillation fingerprinting (AFFIP) study aims to characterize electropathology, enabling development of a novel diagnostic instrument to predict AF onset and early progression. Read More

View Article and Full-Text PDF

Evolutionary Models for the Diversification of Placental Mammals Across the KPg Boundary.

Front Genet 2019 29;10:1241. Epub 2019 Nov 29.

Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States.

Deciphering the timing of the placental mammal radiation is a longstanding problem in evolutionary biology, but consensus on the tempo and mode of placental diversification remains elusive. Nevertheless, an accurate timetree is essential for understanding the role of important events in Earth history (e.g. Read More

View Article and Full-Text PDF
November 2019

No Effect of Interstimulus Interval on Acoustic Reflex Thresholds.

Trends Hear 2019 Jan-Dec;23:2331216519874165

Manchester Centre for Audiology and Deafness, Manchester Academic Health Science Centre, University of Manchester, UK.

The acoustic reflex (AR), a longstanding component of the audiological test battery, has received renewed attention in the context of noise-induced cochlear synaptopathy-the destruction of synapses between inner hair cells and auditory nerve fibers. Noninvasive proxy measures of synaptopathy are widely sought, and AR thresholds (ARTs) correlate closely with synaptic survival in rodents. However, measurement in humans at high stimulus frequencies-likely important when testing for noise-induced pathology-can be challenging; reflexes at 4 kHz are frequently absent or occur only at high stimulus levels, even in young people with clinically normal audiograms. Read More

View Article and Full-Text PDF

Males, Outcrossing, and Sexual Selection in Nematodes.

Genetics 2019 09;213(1):27-57

Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon 97403.

Males of provide a crucial practical tool in the laboratory, but, as the rarer and more finicky sex, have not enjoyed the same depth of research attention as hermaphrodites. Males, however, have attracted the attention of evolutionary biologists who are exploiting the system to test longstanding hypotheses about sexual selection, sexual conflict, transitions in reproductive mode, and genome evolution, as well as to make new discoveries about organismal biology. Here, we review the evolutionary concepts and data informed by study of males of and other We give special attention to the important role of sperm cells as a mediator of inter-male competition and male-female conflict that has led to drastic trait divergence across species, despite exceptional phenotypic conservation in many other morphological features. Read More

View Article and Full-Text PDF
September 2019

Validity of the I-FEED score for postoperative gastrointestinal function in patients undergoing colorectal surgery.

Surg Endosc 2020 05 30;34(5):2219-2226. Epub 2019 Jul 30.

Steinberg-Bernstein Centre for Minimally Invasive Surgery and Innovation, McGill University Health Centre, Montreal, QC, Canada.

Background: Postoperative ileus (POI) is common after gastrointestinal surgery and is associated with significant morbidity and costs. However, POI is poorly defined. The I-FEED score is a novel outcome measure for POI, developed by expert consensus. Read More

View Article and Full-Text PDF

Striatal circuits for reward learning and decision-making.

Nat Rev Neurosci 2019 08;20(8):482-494

Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.

The striatum is essential for learning which actions lead to reward and for implementing those actions. Decades of experimental and theoretical work have led to several influential theories and hypotheses about how the striatal circuit mediates these functions. However, owing to technical limitations, testing these hypotheses rigorously has been difficult. Read More

View Article and Full-Text PDF

Distinct mutational landscape of inverted urothelial papilloma.

J Pathol 2019 09 2;249(1):3-5. Epub 2019 Jul 2.

Department of Pathology, Indiana University School of Medicine, Indianapolis, IN, USA.

A recent study has identified gene mutations involving the MAPK/ERK pathway, particularly the HRAS gene, in all inverted urothelial papillomas (IUPs), in the absence of pathway mutations in TERT promoter, FGFR3, and TP53/RB1genes. Neither recurrence nor progression was observed in IUPs. These data support several longstanding hypotheses: (1) IUPs are benign and do not recur or progress; (2) they harbor mutations that are different from those of urothelial carcinoma; and (3) they arise through different molecular mechanisms than low- or high-grade urothelial carcinoma. Read More

View Article and Full-Text PDF
September 2019

Relict subduction initiation along a passive margin in the northwest Indian Ocean.

Nat Commun 2019 05 21;10(1):2248. Epub 2019 May 21.

Department of Geosciences, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia.

The tectonic evolution of Laxmi basin, presently located along western Indian passive margin, remains debated. Prevailing geodynamic models of Laxmi basin include two mutually competing hypotheses, culminating in either a hyper-stretched continental crust or an oceanic crust overlying an extinct spreading centre. The longstanding conundrum surrounding its precise crustal affinity precludes a complete understanding of the early opening of the Indian Ocean. Read More

View Article and Full-Text PDF

What the replication crisis means for intervention science.

Int J Psychophysiol 2020 08 11;154:3-5. Epub 2019 May 11.

Department of Psychology, Drexel University, United States of America; Department of Neurology, Drexel University, United States of America; Department of Neurology, Perelman School of Medicine, University of Pennsylvania, United States of America.

The provocative paper by Ioannidis (2005) claiming that "most research findings are false" re-ignited longstanding concerns (see Meehl, 1967) that findings in the behavioral sciences are unlikely to be replicated. Then, a landmark paper by Nosek et al. (2015a) substantiated this conjecture, showing that, study reproducibility in psychology hovers at 40%. Read More

View Article and Full-Text PDF

Genomic evidence of survival near ice sheet margins for some, but not all, North American trees.

Proc Natl Acad Sci U S A 2019 04 8;116(17):8431-8436. Epub 2019 Apr 8.

Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor MI 48109.

Temperate species experienced dramatic range reductions during the Last Glacial Maximum, yet refugial populations from which modern populations are descended have never been precisely located. Climate-based models identify only broad areas of potential habitat, traditional phylogeographic studies provide poor spatial resolution, and pollen records for temperate forest communities are difficult to interpret and do not provide species-level taxonomic resolution. Here we harness signals of range expansion from large genomic datasets, using a simulation-based framework to infer the precise latitude and longitude of glacial refugia in two widespread, codistributed hickories ( spp. Read More

View Article and Full-Text PDF

Cauda Equina Syndrome in Ankylosing Spondylitis: Challenges in Diagnosis, Management, and Pathogenesis.

J Rheumatol 2019 12 1;46(12):1582-1588. Epub 2019 Apr 1.

From the Departments of Rheumatology and Neuroradiology, Cedars-Sinai Medical Center, Los Angeles, California; University of Texas Health Science Center at Houston, Houston, Texas; Spondylitis Association of America, Sherman Oaks, California, USA.

Objective: Cauda equina syndrome (CES) is a rare neurologic complication of longstanding ankylosing spondylitis (AS). It is unclear what causes CES, and no proven or effective therapy has been reported to date. We have encountered 6 patients with longstanding AS diagnosed with CES. Read More

View Article and Full-Text PDF
December 2019

Successive Paradigm Shifts in the Bacterial Cell Cycle and Related Subjects.

Authors:
Vic Norris

Life (Basel) 2019 Mar 7;9(1). Epub 2019 Mar 7.

Laboratory of Microbiology Signals and Microenvironment, University of Rouen, 76821 Mont Saint Aignan, France.

A paradigm shift in one field can trigger paradigm shifts in other fields. This is illustrated by the paradigm shifts that have occurred in bacterial physiology following the discoveries that bacteria are not unstructured, that the bacterial cell cycle is not controlled by the dynamics of peptidoglycan, and that the growth rates of bacteria in the same steady-state population are not at all the same. These paradigm shifts are having an effect on longstanding hypotheses about the regulation of the bacterial cell cycle, which appear increasingly to be inadequate. Read More

View Article and Full-Text PDF

Looking for middle ground in cultural attraction theory.

Authors:
Andrew Buskell

Evol Anthropol 2019 Jan 20;28(1):14-17. Epub 2019 Jan 20.

Department of History and Philosophy of Science, University of Cambridge, Cambridge, United Kingdom.

In their article, Thom Scott-Phillips, Stefaan Blancke, and Christophe Heintz do a commendable job summarizing the position and misunderstandings of "cultural attraction theory" (CAT). However, they do not address a longstanding problem for the CAT framework; that while it has an encompassing theory and some well-worked out case studies, it lacks tools for generating models or empirical hypotheses of intermediate generality. I suggest that what the authors diagnose as misunderstandings are instead superficial interpretive errors, resulting from researchers who have attempted to extract generalizable hypotheses from CAT and bring them into contact with the analytical and inferential models of contemporary cultural evolutionary research. Read More

View Article and Full-Text PDF
January 2019