Unsolved Mysteries Research Articles

Shedding light on dark sectors with gravitational waves

The nature of dark matter remains one of the greatest unsolved mysteries in elementary particle physics. It might well be that the dark matter particle belongs to a dark sector completely secluded or extremely weakly coupled to the visible sector. We demonstrate that gravitational waves arising from first-order phase transitions in the early Universe can be used to look for signatures of dark sector models connected to neutron physics. This introduces a new connection between gravitational-wave physics and nuclear physics experiments. Focusing on two particular extensions of the Standard Model with dark U(1) and SU(2) gauge groups constructed to address the neutron lifetime puzzle, we show how those signatures can be searched for in future gravitational-wave and astrometry experiments. Published by the American Physical Society 2024

Systematic Literature Review on Application of Biotechnology on Salak (Salacca spp.) Breeding Program Acceleration: The Unsolved Mysteries

Systematic Literature Review on Application of Biotechnology on Salak (Salacca spp.) Breeding Program Acceleration: The Unsolved Mysteries

1428: “Lattice – The Unsolved Mystery of the Geometry Diagram”

1428: “Lattice – The Unsolved Mystery of the Geometry Diagram”

The importance of prion research.

Over the past four decades, prion diseases have received considerable research attention owing to their potential to be transmitted within and across species as well as their consequences for human and animal health. The unprecedented nature of prions has led to the discovery of a paradigm of templated protein misfolding that underlies a diverse range of both disease-related and normal biological processes. Indeed, the "prion-like" misfolding and propagation of protein aggregates is now recognized as a common underlying disease mechanism in human neurodegenerative disorders such as Alzheimer's and Parkinson's disease, and the prion principle has led to the development of novel diagnostic and therapeutic strategies for these illnesses. Despite these advances, research into the fundamental biology of prion diseases has declined, likely due to their rarity and the absence of an acute human health crisis. Given the past translational influence, continued research on the etiology, pathogenesis, and transmission of prion disease should remain a priority. In this review, we highlight several important "unsolved mysteries" in the prion disease research field and how solving them may be crucial for the development of effective therapeutics, preventing future outbreaks of prion disease, and understanding the pathobiology of more common human neurodegenerative disorders.

Consciousness: A Tangled Hierarchy

Consciousness is one of the greatest unsolved mysteries of the brain. The simple and yet fundamental question, “How do we have subjective experience?” remains a matter of great debate among neuroscientists. These debates have generated some challenges for consciousness research, namely the hard problem—do normal scientific approaches work for consciousness— and the binding problem—how are sensory inputs experienced in a unified manner? Historically, consciousness has been studied by searching for the neural correlates of consciousness which are defined as the minimal brain areas jointly necessary for conscious experience. One of the most popular experimental paradigms used to investigate the neural correlates of consciousness is binocular rivalry. In binocular rivalry, separate images are simultaneously presented to each eye and perception vacillates between them, providing a way of determining which neural changes are due to shifts in perceptual consciousness rather than changes in stimuli. As the research progressed, however, scientists realized that finding correlates of consciousness was insufficient and that explanatory theories of consciousness were needed to make further progress. This review article aims to introduce the field of consciousness research by presenting some of the core challenges to the field: tracing the search for the neural correlates of consciousness through the lens of binocular rivalry, and exploring four popular theories of consciousness. These are higher-order theory, global neuronal workspace theory, integrated information theory, and predictive processing. It concludes with a glance at the future directions of research that aim to resolve the beguiling phenomenon of consciousness.

Неразгаданные тайны синдрома «разбитого сердца»

Неразгаданные тайны синдрома «разбитого сердца»

Integrated metabolomics and transcriptomics reveal that HhERF9 positively regulates salt tolerance in Hibiscus hamabo Siebold & Zuccarini

Hibiscus hamabo Siebold & Zuccarini is one of the few semi-mangrove plants in the genus Hibiscus that can survive in saline-alkali soil and flooded land, but the mechanism underlying its adaptation to salt soil remains unknown. Here, to uncover this unsolved mystery, we characterized the changes in the accumulation of specific metabolites under salt stress in H. hamabo by integrating physiological, metabolic, and transcriptomic data, and found that osmotic adjustment and abscisic acid (ABA) is highly associated with the salt stress response. Further, a weighted gene co-expression network analysis was performed on the root transcriptome data, which identified three key candidate transcription factors responsive to salt stress. Among them, the expression HhERF9 was significantly upregulated under salt stress and ABA treatment and was involved in regulating the expression of genes related to the salt stress response. Further research indicated that HhERF9 enhances the accumulation of proline and soluble sugars by regulating the expression of genes such as NHX2 and P5CS. These findings provide a reference for improving H. hamabo through targeted genetic engineering and lay a theoretical foundation for its future promotion and cultivation in saline-alkali areas.

Distinct SARS-CoV-2 populational immune backgrounds tolerate divergent RBD evolutionary preferences.

Immune evasion is a pivotal force shaping the evolution of viruses. Nonetheless, the extent to which virus evolution varies among populations with diverse immune backgrounds remains an unsolved mystery. Prior to the widespread SARS-CoV-2 infections in December 2022 and January 2023, the Chinese population possessed a markedly distinct (less potent) immune background due to its low infection rate, compared to countries experiencing multiple infection waves, presenting an unprecedented opportunity to investigate how the virus has evolved under different immune contexts. We compared the mutation spectrum and functional potential of the newly derived mutations that occurred in BA.5.2.48, BF.7.14 and BA.5.2.49-variants prevalent in China-with their counterparts in other countries. We found that the emerging mutations in the receptor-binding-domain region in these lineages were more widely dispersed and evenly distributed across different epitopes. These mutations led to a higher angiotensin-converting enzyme 2 (ACE2) binding affinity and reduced potential for immune evasion compared to their counterparts in other countries. These findings suggest a milder immune pressure and less evident immune imprinting within the Chinese population. Despite the emergence of numerous immune-evading variants in China, none of them outcompeted the original strain until the arrival of the XBB variant, which had stronger immune evasion and subsequently outcompeted all circulating variants. Our findings demonstrated that the continuously changing immune background led to varying evolutionary pressures on SARS-CoV-2. Thus, in addition to viral genome surveillance, immune background surveillance is also imperative for predicting forthcoming mutations and understanding how these variants spread in the population.

Functional disorders in amyotrophic lateral sclerosis

Background. Amyotrophic lateral sclerosis (ALS) is a disease of the parts of the nervous system that control voluntary muscle movement. In ALS, motor neurons (nerve cells that control muscle cells) are gradually lost. As this happens, the muscles they control become weak and then nonfunctional, thus leading to muscle weakness, disability, and eventually death. ALS is the most common form of motor neuron disease. Recent studies widely demonstrated that the pattern of progression in sporadic ALS patients is unsolved mystery, especially what factors influence the progression of the disease. Therefore, we conducted a study using ALS Functional Rating Scale-Revised (ALSFRS-R) for disease progression and investigated factors contributing to its rapid rate in The First University Clinic of Tbilisi State Medical University in 2019–2022. Materials and methods. A total of 60 patients with ALS were examined, among them 31 male (51.67 %), 29 female (48.33 %) aged 21–84 years. Riluzole takers, patients with sporadic ALS underwent brain magnetic resonance imaging, and electrophysiological studies were done in all patients. Participants were diagnosed using the Gold Coast criteria and examined with the ALSFRS-R. Survey for factors affecting disease progression was performed with a help of the patient’s caregiver (a disease-specific questionnaire was invented for this purpose, investigating probable progression modifiers). Results. It has been found that recent falls, trauma, surgery, and infection have a drastic impact on disease progression. ALS was found to be a not linear progressive disease and can vary. We have found that 5 % of patients had improvement оn ALSFRS-R, not explained by medication, nor lifestyle change. Conclusions. The rate of ALS progression appears to be a mystery by itself. Predicting the progression rate, and the factors affecting it would be beneficial for ALS patients and may even bring chances to slow or halt the progression. Further research is essential.

How do bacterial endosymbionts work with so few genes?

The move from a free-living environment to a long-term residence inside a host eukaryotic cell has profound effects on bacterial function. While endosymbioses are found in many eukaryotes, from protists to plants to animals, the bacteria that form these host-beneficial relationships are even more diverse. Endosymbiont genomes can become radically smaller than their free-living relatives, and their few remaining genes show extreme compositional biases. The details of how these reduced and divergent gene sets work, and how they interact with their host cell, remain mysterious. This Unsolved Mystery reviews how genome reduction alters endosymbiont biology and highlights a "tipping point" where the loss of the ability to build a cell envelope coincides with a marked erosion of translation-related genes.

Laboratory evidence of Weibel magnetogenesis driven by temperature gradient using three-dimensional synchronous proton radiography.

The origin of the cosmic magnetic field remains an unsolved mystery, relying not only on specific dynamo processes but also on the seed field to be amplified. Recently, the diffuse radio emission and Faraday rotation observations reveal that there has been a microgauss-level magnetic field in intracluster medium in the early universe, which places strong constraints on the strength of the initial field and implies the underlying kinetic effects; the commonly believed Biermann battery can only provide extremely weak seed of 10-21 G. Here, we present evidence for the spontaneous Weibel-type magnetogenesis in laser-produced weakly collisional plasma with the three-dimensional synchronous proton radiography, where the distribution anisotropy directly arises from the temperature gradient, even without the commonly considered interpenetrating plasmas or shear flows. This field can achieve sufficient strength and is sensitive to Coulomb collision. Our results demonstrate the importance of kinetics in magnetogenesis in weakly collisional astrophysical scenarios.

The Tomb and treasury of Hülegü Khan

The Il-Khan ruler Hülegü (1215–1265 CE) was a grandson of Genghis Khan (the founder of the Mongol Empire), a son of Tolui, and a brother of both Möngke Khan and Kublai Khan. He died on February 8, 1265, CE, at an estimated age of 48 years. Unlike our knowledge about the death and burial of Genghis Khan (d. 1227 CE), which is recorded in one of the oldest of the autochthonous chronicles, The Secret History of the Mongols, with no reference to time or place, the approximate location of Hülegü’s final resting place is referenced in several documents. Contemporary Persian resources unanimously suggest that the treasury and royal tomb of Hülegü Khan lie somewhere in Lake Urmia on Shahi Island (Jazīreh-ye-Shāhī), Northwest Iran. Rashīd al-Dīn posited that the Hülegü’s treasury is filled with pillow-size gold ingots and treasures gathered from across the Ilkhanid Empire. The exact location and discovery of this hidden treasure and the burial place of Hülegü remain one of the most persistent unsolved mysteries and none of the later archaeological studies challenged this attribution. This paper will discuss the idea that Shahi Island contains the fabled tomb of the legendary ruler of Ilkhanid Iran (1256–1335 CE) Hülegü, his sons Abaqa Khan (1234–1282 CE), as well as Mongol queens, high priests, and other elites. The findings of this research are important because they could launch a new era for Mongol studies and the archaeology of hidden treasures.

Unsolved Mystery: The $1-million math problem at the heart of computation.

Unsolved Mystery: The $1-million math problem at the heart of computation.

Knowns and unknowns about the neurobiology of stuttering.

Stuttering occurs in early childhood during a dynamic phase of brain and behavioral development. The latest studies examining children at ages close to this critical developmental period have identified early brain alterations that are most likely linked to stuttering, while spontaneous recovery appears related to increased inter-area connectivity. By contrast, therapy-driven improvement in adults is associated with a functional reorganization within and beyond the speech network. The etiology of stuttering, however, remains enigmatic. This Unsolved Mystery highlights critical questions and points to neuroimaging findings that could inspire future research to uncover how genetics, interacting neural hierarchies, social context, and reward circuitry contribute to the many facets of stuttering.

How important is EMT for cancer metastasis?

Epithelial-to-mesenchymal transition (EMT), a biological phenomenon of cellular plasticity initially reported in embryonic development, has been increasingly recognized for its importance in cancer progression and metastasis. Despite tremendous progress being made in the past 2 decades in our understanding of the molecular mechanism and functional importance of EMT in cancer, there are several mysteries around EMT that remain unresolved. In this Unsolved Mystery, we focus on the variety of EMT types in metastasis, cooperative and collective EMT behaviors, spatiotemporal characterization of EMT, and strategies of therapeutically targeting EMT. We also highlight new technical advances that will facilitate the efforts to elucidate the unsolved mysteries of EMT in metastasis.

A model for the hydrogenation and charge states of fullerene C60. Implications for diffuse interstellar band research

The diffuse interstellar bands (DIBs) are a set of sim 600 absorption features at optical and near-infrared wavelengths that are found in the interstellar medium in the Milky Way and other galaxies. They remain mostly unidentified and represent the greatest unsolved mystery in astronomical spectroscopy of the past 100 years. Many studies indicate that the carrier molecules are likely carbonaceous molecules, such as polycyclic aromatic hydrocarbons (PAHs) or fullerenes, a theory that is supported by the identifications of five DIBs in the near-infrared attributed to C$_ This work aims to narrow down which compounds related to C$_ $ could be promising DIB carrier candidates.\ We did so by conducting a theoretical study of its hydrogenation and charge balance. We defined a system of relevant reactions, and for each reaction we computed or derived from the literature a reaction rate coefficient. Assuming a steady state, we then computed a distribution of relative abundances in each hydrogenation and charge state. From the model outcomes, we expect the most abundant hydrogenated buckminsterfullerene compound in the diffuse interstellar medium to be C$_ $H$^+$.

The peroxisome: an update on mysteries 3.0.

Peroxisomes are highly dynamic, oxidative organelles with key metabolic functions in cellular lipid metabolism, such as the β-oxidation of fatty acids and the synthesis of myelin sheath lipids, as well as the regulation of cellular redox balance. Loss of peroxisomal functions causes severe metabolic disorders in humans. Furthermore, peroxisomes also fulfil protective roles in pathogen and viral defence and immunity, highlighting their wider significance in human health and disease. This has sparked increasing interest in peroxisome biology and their physiological functions. This review presents an update and a continuation of three previous review articles addressing the unsolved mysteries of this remarkable organelle. We continue to highlight recent discoveries, advancements, and trends in peroxisome research, and address novel findings on the metabolic functions of peroxisomes, their biogenesis, protein import, membrane dynamics and division, as well as on peroxisome-organelle membrane contact sites and organelle cooperation. Furthermore, recent insights into peroxisome organisation through super-resolution microscopy are discussed. Finally, we address new roles for peroxisomes in immune and defence mechanisms and in human disorders, and for peroxisomal functions in different cell/tissue types, in particular their contribution to organ-specific pathologies.

The primordial black holes solution to the cosmological monopole problem

Recently, the pulsar timing array (PTA) collaborations, including CPTA, EPTA, NANOGrav, and PPTA, announced that they detected a stochastic gravitational wave background spectrum in the nHz band. This may be relevant to the cosmological phase transition suggested by some models. Magnetic monopoles and primordial black holes (PBHs), two unsolved mysteries in the universe, may also have their production related to the cosmological phase transition. Inspired by that, we revisit the model proposed by Stojkovic and Freese, which involves PBHs accretion to solve the cosmological magnetic monopole problem. We further develop it by considering the increase in the mass of the PBHs during accretion and taking the effect of Hawking radiation into account. With these new considerations, we find that solutions to the problem still exist within a certain parameter space. In addition, we also generalize the analysis to PBHs with an extended distribution in mass. This may be a more interesting scenario because PBHs that have accreted magnetic monopoles might produce observable electromagnetic signals if they are massive enough to survive in the late universe.

Quantum Geometry Conserves Baryon Symmetry - The Matter - Antimatter Universe

The Universe that we live in is a universe of matter, even though we know that there must be just as much antimatter around that will balance the matter it appears that the antimatter is nowhere to be found. We know this to be simply true, as a matterantimatter universe would vanish in one annihilation event, which is what apparently happened very, very soon after the big bang. We are here by grace of a very small imbalance in favor of matter, one particle of matter surviving for every one billion matter-antimatter pairs. Other than the mirror matter-antimatter universe hypothesis, or matter-antimatter bubble universe, most research in baryon asymmetry, baryogenesis, is directed at finding a good mechanism for symmetry breaking, following the three conditions set by Sakharov in 1967 [1]. To date there are no viable theories, and the matter-antimatter imbalance remains as one of the great unsolved mysteries in physics. However, this then implies that nature has created a universe that is so out of balance that the dance partner is nowhere to be found. Quantum Geometry is a new proposal to allow baryon symmetry to be conserved, and a universe with 50% matter and 50% antimatter, to actually exist, everywhere. At the lowest level of existence, that of the fundamental particles, both quarks and antiquarks can be used to construct the composite particles of the second level, the subatomic particles, without annihilation. In the heart of the sub-atomic particles, the proton and neutron, the geometry of the gluon equilibrium allows these particles to contain quarks and antiquarks, the proton holding four quarks and one antiquark, the pentaquark, and the neutron being made up of three quark-antiquark pairs [2]. These sub-atomic particles then interact further as particles of matter, avoiding annihilation in the world of matter. Then, Quantum Geometry is used to propose a composite electron. This sub-atomic particle would be made of four antiquarks and one quark, an antimatter pentaquark. The atom then becomes the third level building block of matter, made of protons with a baryon number of +1, neutrons with a baryon number of 0, rather than also +1, and a composite electron with a baryon number of -1, rather than being a point-particle fermion. This allows the universe we see to have a baryon number of 0, to have baryon symmetry, without having to search for the antimatter or to consider that it has all disappeared in an explosion of light. Every atom contains an equal amount of matter and antimatter, held in equilibrium by a powerful geometry that is fully explained in this new theory of Quantum Geometry that will take us beyond relativity theory. Our universe is a balanced geometric matter-antimatter universe, at all levels, each balanced through a zero-point that is anchored in absolute time.

Shallow Subsurface Structure of the Moon: Key Questions for Future Exploration

Lunar shallow subsurface structure is important in revealing the formation and evolution of the Moon. Therefore, a review of key issues in the lunar shallow subsurface structure will help deepen our understanding of the Moon. From a global perspective, lunar shallow subsurface structure is formed by endogenic and exogenic geological processes such as volcanic activities, tectonic activities, meteorite impacts, and space weathering. Its morphological characteristics and stratigraphic structure record the evolution of these geological processes. Recent lunar exploration missions have returned new samples and high-resolution data that have greatly enriched our knowledge. On the basis of reviewing the research progress of radar detection, crater-based excavation analysis, material inversion, and heat flow measurement, we also discuss the processes that contribute to the formation of the lunar shallow surface structure, such as volcanoes, impacts, tectonics, and space weathering. The main hot issues were sorted out and focused on 3 areas: transformation of lunar shallow subsurface structure by geological processes, environment and material composition of the lunar shallow surface structure, and physical properties of lunar shallow surface structure. Overall, existing research on the lunar subsurface has made significant progress, but it has also brought more new unsolved mysteries. It is necessary to introduce new applied payloads such as synthetic aperture radar (SAR), orbiter subsurface investigation radar (OSIR), or time-domain electromagnetic sounding (TDEM) to provide higher-resolution subsurface data, and develop better interpretation methodologies, to further deepen the understanding of the lunar shallow subsurface structure and indeed reveal the mechanism of lunar geological evolution.