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The complex relationship between mitochondrial dynamics and autophagy illustrates how two cellular housekeeping processes are intimately linked, illuminating fundamental principles of cellular homeostasis and shedding light on disparate pathological conditions including several neurodegenerative disorders. Here we review the basic tenets of mitochondrial dynamics i.e., the concerted balance between fusion and fission of the organelle, and its interplay with macroautophagy and selective mitochondrial autophagy, also dubbed mitophagy, in the maintenance of mitochondrial quality control and ultimately in cell viability. We illustrate how conditions of altered mitochondrial dynamics reverberate on autophagy and vice versa. Finally, we illustrate how altered interplay between these two key cellular processes participates in the pathogenesis of human disorders affecting multiple organs and systems. [ABSTRACT FROM AUTHOR]

Abstract Colorectal cancer (CRC) is a significant public health concern, and its development is associated with mitochondrial dysfunction. Mitochondria can adapt to the high metabolic demands of cancer cells owing to their plasticity and dynamic nature. The fusion–fission dynamics of mitochondria play a crucial role in signal transduction and metabolic functions of CRC cells. Enhanced mitochondrial fission promotes the metabolic reprogramming of CRC cells, leading to cell proliferation, metastasis, and chemoresistance. Excessive fission can also trigger mitochondria-mediated apoptosis. In contrast, excessive mitochondrial fusion leads to adenosine triphosphate (ATP) overproduction and abnormal tumor proliferation, whereas moderate fusion protects intestinal epithelial cells from oxidative stress-induced mitochondrial damage, thus preventing colitis-associated cancer (CAC). Therefore, an imbalance in mitochondrial dynamics can either promote or inhibit CRC progression. This review provides an overview of the mechanism underlying mitochondrial fusion–fission dynamics and their impact on CRC biology. This revealed the dual role of mitochondrial fusion–fission dynamics in CRC development and identified potential drug targets. Additionally, this study partially explored mitochondrial dynamics in immune and vascular endothelial cells in the tumor microenvironment, suggesting promising prospects for targeting key fusion/fission effector proteins against CRC. Graphical Abstract

Colorectal cancer (CRC) is a significant public health concern, and its development is associated with mitochondrial dysfunction. Mitochondria can adapt to the high metabolic demands of cancer cells owing to their plasticity and dynamic nature. The fusion–fission dynamics of mitochondria play a crucial role in signal transduction and metabolic functions of CRC cells. Enhanced mitochondrial fission promotes the metabolic reprogramming of CRC cells, leading to cell proliferation, metastasis, and chemoresistance. Excessive fission can also trigger mitochondria-mediated apoptosis. In contrast, excessive mitochondrial fusion leads to adenosine triphosphate (ATP) overproduction and abnormal tumor proliferation, whereas moderate fusion protects intestinal epithelial cells from oxidative stress-induced mitochondrial damage, thus preventing colitis-associated cancer (CAC). Therefore, an imbalance in mitochondrial dynamics can either promote or inhibit CRC progression. This review provides an overview of the mechanism underlying mitochondrial fusion–fission dynamics and their impact on CRC biology. This revealed the dual role of mitochondrial fusion–fission dynamics in CRC development and identified potential drug targets. Additionally, this study partially explored mitochondrial dynamics in immune and vascular endothelial cells in the tumor microenvironment, suggesting promising prospects for targeting key fusion/fission effector proteins against CRC. [ABSTRACT FROM AUTHOR]

The dynamical cluster-decay model (DCM) is employed to analyse the decay of various compound nuclei (CNs) having mass A CN ≈ 200 such as 194 Hg ∗ , 197 Tl ∗ , 202 Pb ∗ and 210 Rn ∗ , formed in 16 O-induced reactions, at common excitation energy E CN ∗ ∼ 45 MeV. Calculations are made for three decay fragment configurations, i.e., spherical, β 2 -deformed 'hot-compact' and β 2 -deformed 'cold-elongated' to study the effect of deformation and orientation in the decay dynamics. The structure of fragmentation potential and preformation probability of the chosen nuclei get the significantly modified after the inclusion of deformation and orientation effects, besides showing a dependence on the mass of CN. Further, an investigation is carried out to see the effect of entrance channel properties on the decay dynamics. For this, three reactions, such as 12 C + 182 W, 16 O + 178 Hf and 40 Ar + 154 Sm are considered which form the 194 Hg ∗ CN at common E CN ∗ ∼ 57 MeV. The barrier characteristics, fragmentation structure, preformation probability, barrier penetrability, evaporation residue and fission cross-sections are calculated to analyse the role of the entrance channel in the subsequent decay dynamics. The calculated neutron evaporation residue and fission cross-sections agree well with the experimental data. The most probable fission fragments are identified for the compound nuclei, and the corresponding experimental validation is called for. Moreover, Bohr's independent hypothesis is tested in view of the survival probability ( P surv ) of the chosen reactions. [ABSTRACT FROM AUTHOR]

We have systematically studied quasifission (QF) and fusion–fission (FF) lifetimes for heavy ion fusion reactions which were used in the synthesis of superheavy elements (SHEs) 104 to 118 as well as attempted to synthesise SHEs 119 and 120 using the DNS model. The dependence of QF on energy, angular momentum, entrance channel parameters, deformation parameters and orientation angles are studied. The study reveals that QF lifetimes are larger for the successful reactions than for the unsuccessful reactions. It is also observed that the study of FF lifetimes of both successful and unsuccessful reactions will not give any clue for the reason of failure of experiments to synthesise superheavy elements. It is also observed that the QF process can be controlled by the projectile of lightly deformed or spherical nuclei. The present study finds the importance in selecting the projectile–target combination for the synthesis of SHEs with Z = 119 and 120. [ABSTRACT FROM AUTHOR]

For the 68Zn + 112Sn reaction the Coulomb parameter Z1Z2 is equal to 1500 that is close to the threshold value for the appearance of quasifission process. It was found that mass-energy distributions of the reaction fragments differ significantly from those obtained in the 36Ar + 144Sm reaction leading to the formation of the same composite system of 180Hg at similar excitation energies of about 50 MeV. In the case of the reaction with 68Zn ions, the mass distribution of fissionlike fragments has a wide two-humped shape with maximum yields at 70 and 110 u for the light and heavy fragments, respectively, instead of 80 and 100 u observed in the fission of 180Hg formed in the 36Ar + 144Sm reaction. The difference is explained by an unexpectedly large contribution (more than 70%) of quasifission in the case of the 68Zn + 112Sn reaction.

Cooperation significantly impacts a species' population dynamics as individuals choose others to associate with based upon fitness opportunities. Models of these dynamics typically assume that individuals can freely move between groups. Such an assumption works well for facultative co-operators (e.g. flocking birds, schooling fish, and swarming locusts) but less so for obligate co-operators (e.g. canids, cetaceans, and primates). With obligate co-operators, the fitness consequences from associations are stronger compared to facultative co-operators. Consequently, individuals within a group should be more discerning and selective over their associations, rejecting new members and even removing current members. Incorporating such aspects into population models may better reflect obligately cooperative species. In this paper, we create and analyze a model of the population dynamics of obligate co-operators. In our model, a behavioral game determines within-group population dynamics that then spill over into between-group dynamics. Our analysis shows that group number increases when population dynamics are stable, but additional groups lead to unstable population dynamics and an eventual collapse of group numbers. Using a more general analysis, we identify a fundamental mismatch between the stability of the behavioral dynamics and the stability of the population dynamics. When one is stable, the other is not. Our results suggest that group turnover may be inherent to the population dynamics of obligate co-operators. The instability arises from a non-chaotic deterministic process, and such dynamics should be predictable and testable. [ABSTRACT FROM AUTHOR]

The fusion and subsequent decay analysis of Z=116 superheavy nucleus formed via 48Ca+248Cm→296Lv*, 50Ti+244Pu→294Lv*,and 58Fe+232Th→290Lv* reactions is carried out using extended l-summed Wong model and dynamical cluster decay model (DCM), respectively. First of all, the experimentally available fusion-fission (A/2±20) data is adequately addressed for 296Lv* and 294Lv* superheavy nuclei using extended l-summed Wong model and the predictions are made for fusion-fission excitation function of 290Lv* nucleus. It is observed that with decrease in mass-asymmetry (ƞ), the contribution of fusion-fission component decreases. This drop is steeper for 50Ti to 58Fe as compared to that for 48Ca to 50Ti. The calculated values of compound nucleus formation probability (PCN) are highest for 48Ca followed by 50Ti and 58Fe. Finally, the mass distribution of decay fragments is studied for 296Lv*, 294Lv*, and 290Lv* nuclei using DCM at near barrier energies. A valley in ACN/2 region results in asymmetric mass distribution for 296Lv* which becomes relatively symmetric for the lighter isotope 290Lv*. [ABSTRACT FROM AUTHOR]

The distinctive pathological hallmarks of Parkinson's disease are the progressive death of dopaminergic neurons and the intracellular accumulation of Lewy bodies enriched in α-synuclein protein. Several lines of evidence from the study of sporadic, familial and pharmacologically induced forms of human Parkinson's disease also suggest that mitochondrial dysfunction plays an important role in disease progression. Although many functions have been proposed for α-synuclein, emerging data from human and animal models of Parkinson's disease highlight a role for α-synuclein in the control of neuronal mitochondrial dynamics. Here, we review the α-synuclein structural, biophysical and biochemical properties that influence relevant mitochondrial dynamic processes such as fusion-fission, transport and clearance. Drawing on current evidence, we propose that α-synuclein contributes to the mitochondrial defects that are associated with the pathology of this common and progressive neurodegenerative disease.

Isospin influence on the decay of hot and rotating compound systems 118,122Ba⁎ and 118,134Ba⁎ formed in 78,82Kr + 40Ca and 78,86Kr + 40,48Ca reactions at incident energies 5.5 and 10 MeV/A, respectively, has been studied using the dynamical cluster-decay model. Binding energies used in the model have been calculated using semi-empirical mass formula of Davidson et al., where the bulk and asymmetry constants have been adjusted to reproduce the ground state mass excess for all the nuclei which have been added to AME2003 and mass table in Möller et al. 1995 to build AME2016 and FRDM2012 data. The theoretical mass excess is considered only for those cases where experimental mass excess was not available. The shell corrections have been calculated with shell closures at 2, 8, 14, 28, 50, 82, 126, 184 for both protons and neutrons and 258 for neutron only. The influence of isospin and incident energies have been seen on the following: mass and charge distribution of the fragments, de-excitation/evaporation, binary decay/fission processes of the compound system, odd-even staggering, isotopic composition, angular momentum distribution of preformation probabilities and decay cross-sections for evaporation and fission like events. The calculated cross-sections for evaporation and fission like events have been compared with experiments and the role of angular momentum on decay/fission processes have been discussed. [ABSTRACT FROM AUTHOR]

In this paper, in order to produce high-energy neutrons, the design of a compact, portable and high efficiency reactor based on a plasma focus device is investigated. The COMSOL Multiphysics software was used to investigate and optimize 16 plasma focus devices with different stored energies for producing neutrons. To keep the fission reactor at the subcritical condition, fuel assembly containing a specific combination of fission fuel of 2 3 8 U – 2 3 9 Pu was used. As a result of energetic neutrons produced in the plasma focus device, no radioactive waste remained in the reactor. In addition, an efficient gas cooling system that absorbed and transferred heat was designed using the COMSOL Multiphysics software. The absorbed heat was transferred to the thermo-photo-voltaic converter, and thus electricity was generated with an efficiency of about 40%. Electrical and thermal energies are calculated in each shot for every plasma focus device. Finally, we showed that high frequency plasma focus devices had a high potential to produce energy. [ABSTRACT FROM AUTHOR]

Using dynamical cluster-decay model, the time scale of fission and light charged particles emitted in the decay of Hf⁎ and Pt⁎ nuclei is estimated. The decay analysis is carried out for isotopes and isobars of 170,174Hf⁎ and 170,174Pt⁎ nuclei. The structural information from the excited Hf⁎ and Pt⁎ nuclei is extracted using the fragmentation potential and preformation probability, which in turn accordingly influence the cross section yields. The cross sections of evaporation residue and fission-fragments are calculated by optimizing the neck length Δ R with in the frame work of dynamical cluster-decay model (DCM). The neck length Δ R provides significant information about the shape elongation of decaying fragments and in turn provides an insight of the reaction time scale. Applying momentum conservation, the velocity and time scale of fission fragments is calculated for 170Hf⁎ nucleus at temperature T = 2.011 MeV , which comes out of the order of (0.7 – 1) × 10 − 21 s and the same for light charged particle is 0.5 × 10 − 21 s. [ABSTRACT FROM AUTHOR]

Abstract Fragment mass distributions from fission of the excited compound nucleus 178Pt have been deduced from the measured fragment velocities. The 178Pt nucleus was created at the JAEA tandem facility in a complete fusion reaction 36Ar + 142Nd, at beam energies of 155, 170 and 180 MeV. The data are indicative of a mixture of the mass-asymmetric and mass-symmetric fission modes associated with higher and lower total kinetic energies of the fragments, respectively. The measured fragment yields are dominated by asymmetric mass splits, with the symmetric mode contributing at the level of ≈ 1 / 3. This constitutes the first observation of a multimodal fission in the sub-lead region. Most probable experimental fragment-mass split of the asymmetric mode, A L / A H ≈ 79 / 99 , is well reproduced by nuclear density functional theory using the UNEDF1-HFB and D1S potentials. The symmetric mode is associated by theory with very elongated fission fragments, which is consistent with the observed total kinetic energy/fragment mass correlation. [ABSTRACT FROM AUTHOR]

Fission-fragment mass distributions were measured for 225,227Pa nuclei formed in fusion reactions of 19F+206,208Pb around fusion barrier energies. Mass-angle correlations do not indicate any quasi-fission like events in this bombarding energy range. Mass distributions were fitted by Gaussian distribution and mass variance extracted. At below-barrier energies, the mass variance was found to increase with decrease in energy for both nuclei. Results from present work were compared with existing data for induced fission of 224,226Th and 228U around barrier energies. Enhancement in mass variance of 225,227Pa nuclei at below-barrier energies shows evidence for presence of asymmetric fission events mixed with symmetric fission events. This is in agreement with the results of mass distributions of nearby nuclei 224,226Th and 228U where two-mode fission process was observed. Two-mode feature of fission arises due to the shell effects changing the landscape of the potential-energy surfaces at low excitation energies. The excitation-energy dependence of the mass variance gives strong evidence for survival of microscopic shell effects in fission of light actinide nuclei 225,227Pa with initial excitation energy ∼30–50 MeV.

Mass distributions of fission fragments from the compound nuclei 180Hg and 190Hg formed in fusion reactions 36Ar + 144Sm and 36Ar + 154Sm, respectively, were measured at initial excitation energies of E⁎(Hg180)=33–66 MeV and E⁎(Hg190)=48–71 MeV. In the fission of 180Hg, the mass spectra were well reproduced by assuming only an asymmetric-mass division, with most probable light and heavy fragment masses A¯L/A¯H=79/101. The mass asymmetry for 180Hg agrees well with that obtained in the low-energy β+/EC-delayed fission of 180Tl, from our earlier ISOLDE(CERN) experiment. Fission of 190Hg is found to proceed in a similar way, delivering the mass asymmetry of A¯L/A¯H=83/107, throughout the measured excitation energy range. The persistence as a function of excitation energy of the mass-asymmetric fission for both proton-rich Hg isotopes gives strong evidence for the survival of microscopic effects up to effective excitation energies of compound nuclei as high as 40 MeV. This behavior is different from fission of actinide nuclei and heavier mercury isotope 198Hg.

The Ca2+-binding protein parvalbumin (PV) and mitochondria play important roles in Ca2+ signaling, buffering and sequestration. Antagonistic regulation of PV and mitochondrial volume is observed in in vitro and in vivo model systems. Changes in mitochondrial morphology, mitochondrial volume and dynamics (fusion, fission, mitophagy) resulting from modulation of PV were investigated in MDCK epithelial cells with stable overexpression/downregulation of PV. Increased PV levels resulted in smaller, roundish cells and shorter mitochondria, the latter phenomenon related to reduced fusion rates and decreased expression of genes involved in mitochondrial fusion. PV-overexpressing cells displayed increased mitophagy, a likely cause for the decreased mitochondrial volumes and the smaller overall cell size. Cells showed lower mobility in vitro, paralleled by reduced protrusions. Constitutive PV down-regulation in PV-overexpressing cells reverted mitochondrial morphology and fractional volume to the state present in control MDCK cells, resulting from increased mitochondrial movement and augmented fusion rates. PV-modulated, bi-directional and reversible mitochondrial dynamics are key to regulation of mitochondrial volume. [ABSTRACT FROM AUTHOR]

High-power lasers with irradiances of >1020 Wcm-2 are able to produce high-energy x-rays, y-rays and neutrons, also can accelerate charged particles, and trigger all kind of nuclear reactions. The basic concept of the fusion-fission reaction scenario based on high dense laser accelerated particles or ion bunches. The fusion-fission reaction systems consist of production and reaction target. In this study, we calculated deuterium acceleration in solid targets by using 2D EPOCH PIC codes. It was assumed that the laser system had a power of 200TW, 5J energy and 25fs to accelerate the deuterons at the production target. 200 TW laser systems can reach the irradiances up to 1020 Wcm-2 by focusing around 10 |rm focal spot on target. It was found that table top Terawatt lasers can be used to for fusion-fission studies by accelerating deuterons up to 10 MeV. Monte Carlo code MCNPX2.7.0 was used for the simulations of fusion-fission target systems. The accelerated deuterons from the production target induce nuclear fission reactions in the thorium layer of the reaction target. The thorium layer, the fusion layer and the CH2 layer in the reaction target have a thickness of around 5 |rm. [ABSTRACT FROM AUTHOR]

The dynamics of the fission process is expected to affect the evaporation residue cross section because of the fission hindrance due to the nuclear viscosity. Systems of intermediate fissility constitute a suitable environment for testing such hypothesis since they are characterized by evaporation residue cross sections comparable or larger than the fission ones. Observables related to emitted charged particles, due to their relatively high emission probability, can be used to put stringent constraints on models describing the excited nucleus decay and to recognize the effects of fission dynamics. In this work model simulations are compared with the experimental data collected via the S 32 + 100 Mo reaction at E lab = 200  MeV . Consequently we pointed out, exploring an extended set of evaporation channel observables, the limits of the statistical model and the large improvement obtained with a dynamical model. Moreover we stress the importance of using an apparatus covering a large fraction of 4 π to extract observables. Finally, we discuss the opportunity to measure more sensitive observables by a new detection device in operation at LNL. [ABSTRACT FROM AUTHOR]

The dynamical cluster decay model (DCM) is employed to explore the relative effect of sticking ( I S ) and non-sticking ( I N S ) limits of moment of inertia (MOI) in the decay of hot and rotating 214,216 Rn ⁎ compound nuclei, formed in 16,18 O + 198 Pt reactions. Beside this, the nuclear deformation effects i.e. quadrupole β 2 (static and dynamic) and higher order static deformations up to hexadecapole ( β 4 ) are duly incorporated and studied within DCM. The influence of both ‘ I N S / I S ’ addressing rotational energy component and ‘deformations’ is gauged through the barrier characteristics, preformation factor and barrier lowering effects. The experimentally given ER and ff data is addressed by optimizing the neck-length Δ R , that strongly depends on the limiting angular momentum, which in turn depends on the sticking or non-sticking limits of interaction. In addition to this, the influence of increase in energy and neutron number is probed in reference to ER survival probability of Rn compound nucleus. Finally, the ff cross-sections of 214,216 Rn ⁎ nuclei are predicted within sticking limit of moment of inertia as the same seems to be more suitable for such decay paths. [ABSTRACT FROM AUTHOR]

The characteristics of fission fragments of various highly-excited nuclei with 119 ≤ A ≤ 218 , which are formed by γ - and α -captures, and by fusion–fission reactions, are discussed in details. The yields of fission fragments of these nuclei are related to the number of states of the two-fragment systems at the two-body saddle points. The various experimental distributions of fission fragments are well described in the model. [ABSTRACT FROM AUTHOR]

It is shown that the potential energy surface of the two separated fragments has the saddle point, which takes place at small distance between the surfaces of well-deformed fragments. The height of this two-body saddle point is larger than the height of one-body fission barrier for nuclei with A ≲ 220 . The mass yields of the fission fragments, which are appearing at the fission of nuclei with A ≲ 220 , are related to the number of states of the two-fragment systems at the two-body saddle points. The characteristics of kinetic energy of fragments are described by using the trajectory motion equations with the dissipation terms. The Gaussian distribution of the final kinetic energy around the classical value of this energy induced by the stochastic fluctuations is taken into account at an evaluation of the total kinetic energy distributions of the fission fragments. [ABSTRACT FROM AUTHOR]

While collective decision-making is recognised as a significant contributor to fitness in social species, the opposite outcome is also logically possible. We show that collective movement decisions guided by individual bison sharing faulty information about habitat quality promoted the use of ecological traps. The frequent, but short-lived, associations of bison with different spatial knowledge led to a population-wide shift from avoidance to selection of agricultural patches over 9 years in and around Prince Albert National Park, Canada. Bison were more likely to travel to an agricultural patch for the first time by following conspecifics already familiar with agricultural patches. Annual adult mortality increased by 12% due to hunting of bison on agricultural lands. Maladaptive social behaviour accordingly was a major force that contributed to a ~50% population decline in less than a decade. In human-altered landscapes, social learning by group-living species can lead to fitness losses, particularly in fusion-fission societies. [ABSTRACT FROM AUTHOR]

Steady state tokamak with deuterium-tritium plasma is considered as a basis for fusion neutron source for a hybrid fusion-fission reactor. Prototypes of such a system can be developed on the basis of the present day tokamaks as the plasma power gain factor Q ~ 1 is required for hybrid applications. Significant population of fast ions can be supported by a powerful neutral beam injection heating in regimes with Q ~ 1. The reaction rate for fast ions greatly exceeds the rate for thermal Maxwellian ions. The possible ranges of parameters are discussed for medium size tokamaks with minor plasma radius a = 0.5-1 m. Power and sizes of the neutron source are determined by the value of the injection energy. Power gain Q ≈ 1 can be achieved with injection energy of deuterium about 130 keV and tritium energy about 200 keV. Neutron power of 30-40 MW can be realized with a ≈ 1 m, and about of few megawatts with a ≈ 0.5 m. [ABSTRACT FROM AUTHOR]

Neutronic performance and inventory analyses were conducted to quantify the damage and gas production rates in candidate materials when used in a fusion-fission hybrid system first wall (FW). The structural materials considered are austenitic SS, Cu-alloy and V- alloys. Plasma facing materials included Be, and CFC composite and W. It is shown that the highest damage rates and gas particles production in materials are experienced within the FW region of a hybrid similar to a pure fusion system. They are greatly influenced by a combined neutron energy spectrum formed by the two-component fusion-fission neutron source in front of the FW and in a subcritical fission blanket behind. These characteristics are non-linear functions of the fission neutron source intensity. Atomic displacement damage production rate in the FW materials of a subcritical system (at the safe subcriticality limit of ∼0.95 and the neutron multiplication factor of ∼20) is almost ∼2 times higher compared to the values distinctive for a pure fusion system at the same 14 MeV neutron FW loading. Both hydrogen (H) and helium (He) gas production rates are practically on the same level except of about ∼4–5 times higher He-production in austenitic and reduced activation ferritic martensitic steels. A proper simulation of the damage environment in hybrid systems is required to evaluate the expected material performance and the structural component residence times. [ABSTRACT FROM AUTHOR]

Fission instabilities induced by mechanical and thermal stresses on intermediate nuclear systems in heavy-ion reactions are poorly understood but should reveal independent evidence for the nuclear equation of state (EoS), notably the tensile strength of finite nuclei. Experimental evidence is presented in support of a new mode of prompt fission of the composite nucleus formed in central Kr+Ca collisions at only a few MeV per nucleon above the interaction barrier. The new process recalls the 'L-window for fusion' phenomenon, which was predicted by the early reaction theory and reappears in modern DFT model calculations. [ABSTRACT FROM AUTHOR]

This paper summarizes the results of some of the recent fusion-fission experiments carried out at the National Array of Neutron Detectors (NAND) Phase-01 installed at the Pelletron + LINAC accelerator facility of Inter-University Accelerator Centre (IUAC), New Delhi. Pre-scission neutron multiplicity excitation functions are measured for the Fr, Rn and Po compound nuclei populated through the fusion of the F+Pt, O+Pt and C+Pt systems, respectively. Pre-scission neutron yields from these reactions are compared with the extensive statistical model calculations to look for the effects due to the compound nucleus shell closure, N/ Z ratio of the compound nucleus, magnitude of the saddle-point shell corerction and fission time-scale. [ABSTRACT FROM AUTHOR]

An overview of the experimental result on simultaneous measurement of pre-scission neutron, proton, α-particle and GDR γ-ray multiplicities for the reaction Si +Lu at 159 MeV using the BARC-TIFR Pelletron-LINAC accelerator facility is given. The data were analysed using deformation-dependent particle transmission coefficients, binding energies and level densities which are incorporated in the code JOANNE2 to extract fission time-scales and mean deformation of the saddle-to-scission emitter. The neutron, light charged particle and GDR γ-ray multiplicity data could be explained consistently. The emission of neutrons seems to be favoured towards larger deformation as compared to charged particles. The pre-saddle time-scale is deduced as (0-2) × 10 s whereas the saddle-to-scission time-scale is (36-39) × 10 s. The total fission time-scale is deduced as (36-41) × 10 s. [ABSTRACT FROM AUTHOR]

Inelastic scattering of high energy fusion neutrons does affect the performance of fusion blanket based on the choice of different materials. It will also affect the behavior of source neutrons in a subcritical fusion fission hybrid blanket and consequently the transmutation and tritium breeding performance. A fusion fission hybrid test blanket module (HTBM) is designed which is presumed to be tested in a large sized tokamak and plasma neutron source is similar to ITER. In this preliminary design of HTBM the neutron source and loss factors are computed for the detailed neutronic performance analysis. The neutronic analysis of hybrid blanket module is performed for five different TRU fuel types: TRU-Zr, TRU-Mo, TRU-Oxide, TRU-Carbide and TRU-Nitride. In this module design, it is aimed to burn and transmute the TRU nuclides from high-level radioactive waste of PWR spent fuel. The effect of TiC reflector on transmutation and tritium breeding performance of HTBM is also quantified. MCNPX is used for neutronic computations. Neutron spectrum, capture to fission ratio and waste transmutation ratio of each fuel type are compared to evaluate their waste transmutation performance. Tritium breeding ratio is also compared for two coolant options: Li and LiPb eutectic. [ABSTRACT FROM AUTHOR]

The dynamics involved in the decay of light mass nuclei formed in asymmetric channels 12C + 28Si, 11B + 28Si and 12C + 27Al have been investigated using the dynamical cluster-decay model (DCM). In reference to the experimentally measured charge particle cross-sections, the fragment masses contributing towards the decay of 40Ca* and 39K* nuclei have been identified using spherical choice of fragmentation. Also, the role of entrance channel has been investigated by studying the decay of 39K* nuclear system formed in two different reactions at same excitation energy. The behavior of fragmentation potential, preformation probability, penetrability and emission time, is analyzed to figure out the favorable mass fragments, their relative emergence and the entrance channel effects observed in the decay of light mass nuclei. In addition to this, the cross-sections for the light particles (LPs) and heavier charge fragments have been estimated for the compound nucleus (CN) decay. Besides this, one of the noncompound nucleus (nCN) process, deep inelastic collision (DIC) has been addressed in context of DCM approach for the first time. The cross-sections obtained in framework of DCM for both CN and nCN processes are found to have nice agreement with the available experimental data. [ABSTRACT FROM AUTHOR]

Highlights: [•] Conceptual design study of fusion-fission hybrid reactor for waste transmutation. [•] MCNPX and MONTEBURNS are compared for transmutation performance of WT-Hyb. [•] Detailed neutronic performance of final optimized Hyb-WT design is analyzed. [•] A new tube-in-duct core design is implemented and compared with pin type design. [•] Study shows many aspects of hybrid reactor even though scope was limited to neutronic analysis. [ABSTRACT FROM AUTHOR]

Abstract: Tokamak neutron sources would allow near term applications of fusion such as fusion–fission hybrid reactors, elimination of nuclear wastes, production of radio-isotopes for nuclear medicine, material testing and tritium production. The generation of neutrons with fusion plasmas does not require energetic efficiency; thus, nowadays tokamak technologies would be sufficient for such purposes. This paper presents some key technical details of a compact (∼1.8m3 of plasma) superconducting spherical tokamak neutron source (STNS), which aims to demonstrate the capabilities of such a device for the different possible applications already mentioned. The T-11 transport model was implemented in ASTRA for 1.5D simulations of heat and particle transport in the STNS core plasma. According to the model predictions, total neutron production rates of the order of ∼1015 s−1 and ∼1013 s−1 can be achieved with deuterium/tritium and deuterium/deuterium respectively, with 9MW of heating power, 1.4T of toroidal magnetic field and 1.5MA of plasma current. Engineering estimates indicate that such scenario could be maintained during ∼20s and repeated every ∼5min. The viability of most of tokamak neutron source applications could be demonstrated with a few of these cycles and around ∼100 cycles would be required in the worst cases. [Copyright &y& Elsevier]

Abstract: A Water-cooled Pressure Tube Energy production blanket (WPTE) for fusion driven subcritical reactor has been designed to achieve 3000MW thermal power with self-sustaining tritium cycle. Pressurized water has great advantages in energy production; however the high pressure may cause some severe structural design issues. This paper proposes a new concept of water-cooled blanket. To solve the problem of the high pressure of the coolant, the pressure tube was adopted in the design and in the meantime, the thickness of the first wall can be significantly reduced as result of adopting pressure tube. The numerically simulating and calculating of temperature, stress distribution and flow analyses were carried out and the feasibility of using water as coolant was discussed. The results demonstrated the engineering feasibility of the water-cooled fusion–fission hybrid reactor blanket module. [Copyright &y& Elsevier]

Abstract: In reference to experimental data on the fusion of a proton-halo projectile with a target, a systematic decay study of is carried out in the framework of the dynamical cluster-decay model (DCM). The calculations suggest that the fusion excitation function of consists of light particles (LPs) as the most dominant contributors, followed by intermediate mass fragments (IMFs) and fission fragments. A description of deformation effects is also provided by considering spherical and deformed choice of fragmentation up to quadrupole ( ) and hexadecapole ( ) deformation. The DCM-based excitation functions agree well with the observed experimental cross sections for all three choices of fragmentation. The ℓ-summed Wong model is also employed to analyze the fusion cross section, which seems to work well, except for the minimum energy that lies below the barrier. Evidently, at below-barrier energy, the Wong model requires further barrier modification, which in the DCM, is accounted by its inbuilt property of barrier modification. Predictions of cross sections at higher extrapolated energies have also been done using both the DCM and ℓ-summed Wong model. [Copyright &y& Elsevier]

Mitochondria are dynamic structures for which fusion and fission are well characterized for rapidly dividing cells in culture. Based on these data, it has recently been proposed that high respiratory activity is the result of fusion and formation of mitochondrial reticulum, while fission results in fragmented mitochondria with low respiratory activity. In this work we test the validity of this new hypothesis by analyzing our own experimental data obtained in studies of isolated heart mitochondria, permeabilized cells of cardiac phenotype with different mitochondrial arrangement and dynamics. Additionally, we reviewed published data including electron tomographic investigation of mitochondrial membrane-associated structures in heart cells. Oxygraphic studies show that maximal ADP-dependent respiration rates are equally high both in isolated heart mitochondria and in permeabilized cardiomyocytes. On the contrary, these rates are three times lower in NB HL-1 cells with fused mitochondrial reticulum. Confocal and electron tomographic studies show that there is no mitochondrial reticulum in cardiac cells, known to contain 5,000-10,000 individual, single mitochondria, which are regularly arranged at the level of sarcomeres and are at Z-lines separated from each other by membrane structures, including the T-tubular system in close connection to the sarcoplasmic reticulum. The new structural data in the literature show a principal role for the elaborated T-tubular system in organization of cell metabolism by supplying calcium, oxygen and substrates from the extracellular medium into local domains of the cardiac cells for calcium cycling within Calcium Release Units, associated with respiration and its regulation in Intracellular Energetic Units. [ABSTRACT FROM AUTHOR]

Abstract: In developed countries, increased life expectancy is accompanied by an increased prevalence of age-related disorders like cancer and neurodegenerative diseases. Albeit the molecular mechanisms behind the clinically, pathologically and etiologically heterogeneous forms of neurodegeneration are often unclear, impairment of mitochondrial fusion–fission and dynamics emerged in recent years as a feature of neuronal dysfunction and death, pinpointing the need for animal models to investigate the relationship between mitochondrial shape and neurodegeneration. While research on mammalian models is slowed down by the complexity of the organisms and their genomes, the long latency of the symptoms and by the difficulty to generate and analyze large cohorts, the lower metazoan Drosophila melanogaster overcomes these problems, proving to be a suitable model to study neurodegenerative diseases and mitochondria-shaping proteins. Here we will summarize our current knowledge on the link between mitochondrial shape and models of neurodegeneration in the fruitfly. This article is part of a Special Issue entitled ‘Mitochondrial function and dysfunction in neurodegeneration’. [Copyright &y& Elsevier]

The karyotype and numeric changes in chromosomes among taxa of Lycoris (spider lilies) have been attributed to whole-arm rearrangements; however, the history of karyotype evolution of Lycoris is still ambiguous. In the natural habitat, one-third of Lycoris taxa are interspecific hybrids that are mainly sterile and extremely diverse in morphologies. Lycoris are geophytes with the reproductive stage initiated inside the bulbs during the storage period, which brings some inconveniences in collecting meiotic materials for studying chromosome pairing. The partial fertility of an artificial F1 interspecific hybrid between L. aurea (2 n = 14) and L. radiata (2 n = 22) provides an alternative option for tracing the meiotic process in F1 hybrids. The chromosome compositions of those functional gametes generated by the F1 hybrid could be recovered according to the chromosome complements of backcross progenies. We perform genomic in situ hybridization (GISH) analysis on somatic chromosomes of 34 BC1 plants (2 n = 14-22) to reveal chromosomal divergences in number and composition of those functional gametes. GISH results also indicated a high homology between the MT- and A-genomes of Lycoris, reflecting on the partial fertility and frequently homoeologous recombination at meiosis of the F1 interspecific hybrids. The diverse chromosome complements and recombinant patterns presented in these functional gametes suggested that interspecific hybridization is an important force in driving diversification among Lycoris species. We suggest that the MT-karyotype genome may be the ancestral type in Lycoris, and some other chromosomal rearrangements in addition to centromeric fission may have played roles in the karyotype evolution of Lycoris. [ABSTRACT FROM AUTHOR]