Intermediate Density Research Articles

A velocity field level set method for topology optimization of piezoelectric layer on the plate with active vibration control

Vibration control has significant applications in many engineering areas to achieve designed vibration performances or suppress structural fatigue and failure. This paper presents a velocity field level set method for topology optimization of the piezoelectric layer on a plate with active vibration control. The material distribution of the piezoelectric layer and the topology optimization model for this problem is formulated in the level set framework, which can precisely track the layout (topology/shape) of piezoelectric layers with clear/smooth boundaries. Compared with the density-based method, the level set method can avoid the difficulties in the definition of material distributions and piezoelectric material properties for intermediate densities, which also leads to more accurate vibration control. We employ the constant gain velocity feedback as the vibration control algorithm. The dynamic compliance is set as the objective function and treated as the index representing the plate’s vibration level. Using the velocity field level set method can map the original variational boundary shape optimization problem into the finite dimensional space and solve the optimization problem efficiently by general optimizers. We also show that the self-adjoint scheme can be used in the sensitivity analysis, which avoids solving additional adjoint problems. To verify the validity and efficiency of the proposed method, we give three numerical examples, in which the influence of the external frequency and the constant gain coefficient on optimization results are also discussed.

Co-Flowering Plant Densities Affect Bee Visitation to a Focal Plant Species, but Bee Genera Differ in Their Response

The relative densities of co-flowering plant species can affect pollinator foraging behavior, i.e., bee choice of which plants to visit in a foraging path. Because animal-pollinated plants depend on sequential pollinator visits to conspecifics for successful reproduction, understanding the relationship between relative densities of co-flowering plants and bee visits within a foraging path is necessary to determine whether co-flowering species facilitate or compete for bee visitation. We examined the role of relative co-flowering plant species densities in determining bee visits to two focal plant species (Astragalus scaphoides and Penstemon albertinus) within foraging paths by following individual bees in natural multispecies co-flowering plant communities. We found that conspecific and heterospecific plant density influenced the proportion of visits to the focal plant species during foraging bouts, but effects of density differed among bee groups. Considering all bees, Lupinus spp. facilitated visits to A. scaphoides while Castilleja spp. competed with A. scaphoides for visits. When three bee groups, Bombus, Anthophora/Eucera, and “small bees,” were modeled separately, Bombus consistently visited A. scaphoides more than expected regardless of its density and P. albertinus less than expected at intermediate densities. Anthophora/Eucera exhibited a nonlinear response to A. scaphoides floral density but visited P. albertinus in direct proportion to its density. “Small bees” visited both plants in direct proportion to their densities. Our results highlight that bee groups should be treated separately in models of pollinator visitation behavior, and that the composition and density of the co-flowering plant community may impact reproductive success of focal plant species.

Pseudo 3D topology optimization of microchannel heat sink with an auxiliary objective

This paper investigated the application of pseudo 3D (P3D) variable-density topology optimization to the design of microchannel heat sink (MHS). To mitigate the grey-element issue and improve the precision of P3D model, outside surface viscous dissipation, adaptive equivalent heat transfer coefficient and auxiliary objective was introduced. The effects of adaptive equivalent heat transfer coefficient, auxiliary objective and its corresponding weight factor on the optimal design were analyzed. The results showed that the new proposed topological model can effectively mitigate intermediate density, improved accuracy and produced a well-defined structure. Furthermore, to validate the design of topology optimization, full 3D numerical simulations were adopted to investigate the fluid flow and heat transfer performance of the topological model and the results were compared with the conventional straight MHS. It is found that the increase of average inlet velocity and temperature uniformity of the topological MHS can be up to 305% and 69%, respectively, under the same inlet pressure. While under the same pumping power consumption, the average heat source temperature of the topological microchannel heat sink can be 9.3°C lower than the conventional one.

Electromagnetism in quark matter at intermediate densities

Several anomalous electromagnetic effects that can take place in quark matter at low temperatures and intermediate densities will be discussed. The anomalous transport properties of the spatially inhomogeneous phase of quark matter known as the Magnetic Dual Chiral Density Wave (MDCDW) phase will be reviewed. Going beyond mean-field approximation, it will be shown how linearly polarized electromagnetic waves that penetrate the MDCDW medium mix with the phonon fluctuations to give rise to two hybridized modes of propagation called axion polaritons. Finally, some possible implications of these results for the astrophysics of neutron stars will be indicated.

Rhesus macaques compensate for reproductive delay following ecological adversity early in life.

Adversity early in life can shape the reproductive potential of individuals through negative effects on health and life span. However, long‐lived populations with multiple reproductive events may present alternative life history strategies to optimize reproductive schedules and compensate for shorter life spans. Here, we quantify the effects of major hurricanes and density dependence as sources of early‐life ecological adversity on Cayo Santiago rhesus macaque female reproduction and decompose their effects onto the mean age‐specific fertility, reproductive pace, and lifetime reproductive success (LRS). Females experiencing major hurricanes exhibit a delayed reproductive debut but maintain the pace of reproduction past debut and show a higher mean fertility during prime reproductive ages, relative to unaffected females. Increasing density at birth is associated to a decrease in mean fertility and reproductive pace, but such association is absent at intermediate densities. When combined, our study reveals that hurricanes early in life predict a delay‐overshoot pattern in mean age‐specific fertility that supports the maintenance of LRS. In contrast to predictive adaptive response models of accelerated reproduction, this long‐lived population presents a novel reproductive strategy where females who experience major natural disasters early in life ultimately overcome their initial reproductive penalty with no major negative fitness outcomes. Density presents a more complex relation with reproduction that suggests females experiencing a population regulated at intermediate densities early in life will escape density dependence and show optimized reproductive schedules. Our results support hypotheses about life history trade‐offs in which adversity‐affected females ensure their future reproductive potential by allocating more energy to growth or maintenance processes at younger adult ages.

Concentration and Cavitation in the Vanishing Pressure Limit of Solutions to a 3 × 3 Generalized Chaplygin Gas Equations

The phenomena of concentration and cavitation are identified and analyzed by studying the vanishing pressure limit of solutions to the 3x3 isentropic compressible Euler equations for generalized Chaplygin gas (GCG) with a small parameter. It is rigorously proved that, any Riemann solution containing two shocks and possibly one-contact-discontinuity of the GCG equations converges to a delta-shock solution of the same system as the parameter decreases to a certain critical value. Moreover, as the parameter goes to zero, that is, the pressure vanishes, the limiting solution is just the delta-shock solution of the pressureless gas dynamics (PGD) model, and the intermediate density between the two shocks tends to a weighted δ-measure that forms the delta shock wave; any Riemann solution containing two rarefaction waves and possibly one contact-discontinuity tends to a two-contact-discontinuity solution of the PGD model, and the nonvacuum intermediate state in between tends to a vacuum state. Finally, some numerical results are presented to exhibit the processes of concentration and cavitation as the pressure decreases.

Compounded effects of sea urchin grazing and physical disturbance on macroalgal canopies in the lagoon of Moorea, French Polynesia

Release from herbivory is a factor underpinning coral replacement by macroalgae. Once macroalgae have achieved dominance, shifts back to the coral-dominated state can be hindered by stabilizing feedbacks. Thus, restoring herbivore assemblages alone can be insufficient to trigger coral recovery. However, herbivores could control macroalgal recovery in the aftermath of physical disturbances removing macroalgae. Diadematid urchins at Moorea (French Polynesia) have collapsed in the last decade. By means of a manipulative field experiment, we tested the interactive effects of physical disturbance and increased diadematid densities on macroalgae inside the lagoon. Massive Porites colonies, referred to as ‘bommies’, were assigned to 3 different macroalgal removal treatments (removal of stipes and fronds of the canopy-forming macroalgae Turbinaria ornata and Sargassum pacificum, total removal of erect macroalgae or untouched) and exposed to 3 different urchin densities (absent, low [~0.5 ind. m-2], and intermediate [~1 ind. m-2]). After 1 yr, sea urchins had no effect on the covers of S. pacificum and T. ornata when macroalgal canopies were left untouched. Urchins could control the recovery of S. pacificum on total macroalgal removal bommies, but not that of T. ornata. However, urchins, even when at intermediate densities, did not generate major changes in the structure of benthic assemblages on experimental bommies. Our study indicates that a moderate increase in diadematid densities is unlikely to reduce the extent of macroalgal stands in Moorea back reefs unless associated with the recovery of other herbivore guilds able to remove adult macroalgae (i.e. browsers).

Specific density as parameter for separating feed ingredients

Description of the subject. Specific densities of 13 samples of eight vegetable feed ingredients and of blood meal have been established. Objectives. The aim of the study was to use the parameter specific density for classification of a selection of feed materials. The range of specific densities for each of the tested materials could support the identification of ingredients in a compound feed. Ingredients in mixtures could be separated when different specific densities apply to these ingredients. Method. The share of the flotate and of the sediment of each of the tested materials has been established in duplicate along a range of increased specific density of the solvent mixture, from 1.22 g·cm-3 up to 1.52 g·cm-3, initially in four steps. Intermediate densities have been used where appropriate for collecting more detailed ranges. The specific densities which resulted in approximately 100% sediment and in approximately 100% flotate are used as indicators for the range of the specific density of that material. Results. The materials used appeared to show three different ranges of specific density: corn gluten and blood meal (1.12 – 1.32 g·cm-3), corn distillers’ grain, rapeseed kernel meal, soya kernel meal and wheat middlings (1.25 – 1.42 g·cm-3), and palm kernel meal, citrus pulp and beet pulp (1.35 – 1.55 g·cm-3). The specific densities range from those found for vertebrate muscles and insect fragments (below 1.3 g·cm-3) up to the specific density of bone fragments (exceeding 1.62 g·cm-3). Four mixed samples, each existing of two different ingredients at a ratio of 1:1 (w/w) were tested with solutions at different specific densities. The ingredients of each mixed sample appeared to separate in the expected fractions, predominantly in either the flotate or in the sediment. Conclusions. The experiments show that separation based on specific density can assist in the identification of feed ingredients in one or more combinations of sediment and flotate fractions.

Holographic dense QCD in the Veneziano limit

Solving the properties of dense QCD matter is an extremely challenging problem because standard theoretical tools do not work at intermediate densities. The gauge/gravity duality may help to provide answers in this region. I give a brief review of recent progress in this field, focusing on the V-QCD model, which is one of the most sophisticated holographic models of QCD. I discuss predictions for the phase diagram, the equation of state, and properties of baryons. I apply these results to analyze the properties of neutron stars and to quark matter production in neutron star mergers.

An investigation of demographic and component Allee effects in the Madagascar hissing cockroach

AbstractPopulation density affects the behaviour and population dynamics of insects, but the nature of that effect may depend on the degree of sociality. We experimentally manipulated initial population density of a subsocial insect, the Madagascar hissing cockroach,Gromphadorhina portentosaSchaum, 1853 (Blattodea: Blaberidae), to determine its effect on vital rates and population dynamics. In accordance with the predicted Allee effect, we hypothesised that intermediate cockroach population density will increase per capita birth rates and cause a higher population growth rate relative to smaller and larger population densities. After tracking 12 experimental populations (three replicates of four initial population densities) for 15 months, we found evidence of Allee effects in this insect. Per capita birth rates showed a quadratic response, with rates highest at intermediate population densities, suggesting a component Allee effect. Contrary to expectations for a demographic Allee effect, population growth rates showed negative density dependence. The proportion of adult females in the population increased with population density, but the mechanism for this increase is not known. Our findings provide evidence for at least one form of Allee effect inG. portentosaand shows a possible connection between subsocial behaviour and population-level responses.

EVALUATING QUINOA LODGING RISK AND YIELD UNDER DIFFERENT IRRIGATION THRESHOLDS, NITROGEN RATES AND PLANTING DENSITIES IN NORTH-WESTERN CHINA

<List> <ListItem><ItemContent> ● A moderate irrigation threshold of −25 kPa gave the greatest actual yield. </ItemContent></ListItem> <ListItem><ItemContent> ● Nitrogen rates of 80−160 kg·ha⁻¹ reduced lodging risk without yield decrease. </ItemContent></ListItem> <ListItem><ItemContent> ● Planting density of 30 plants·m⁻² provided both high yield and lodging resistance. </ItemContent></ListItem> <ListItem><ItemContent> ● A lower-stem lodging index was best for prediction of quinoa lodging risk. </ItemContent></ListItem></List> Lodging is a major yield-limiting factor of quinoa production. In 2018 and 2019, the orthogonal field experiments were conducted to investigate the responses of quinoa lodging risk and yield to irrigation threshold (soil matric potential of −15, −25 and −55 kPa), nitrogen rate (80, 160 and 240 kg·ha⁻¹) and planting density (20, 30 and 40 plants m⁻²). Results showed that high irrigation thresholds and nitrogen rates significantly (<i>P</i> < 0.05) increased plant height and fresh weight per plant, and high planting densities reduced stem diameter and strength, all of those led to significantly ( <i>P</i> < 0.05) high lodging risks. The −15 and −55 kPa treatments gave the lowest actual yield ( <i>P</i> < 0.05) in 2018 and 2019, respectively. Higher lodging rate with a nitrogen rate of 240 kg·ha⁻¹ resulted in a lower actual yield than 80 and 160 kg·ha⁻¹ in both years. Planting density of 30 plants m⁻² gave a significantly (<i>P</i> < 0.05) greater estimated yield than 20 plants m⁻² and had a lower lodging rate than 40 plants m⁻², resulting in the maximum actual yield among planting densities. In conclusion, a moderate irrigation threshold of −25 kPa, a nitrogen rate of 80−160 kg·ha⁻¹ and an intermediate planting density of 30 plants m⁻² were determined to be best for quinoa cultivation in North-western China. In addition, the lower-stem lodging index (quarter plant height) could evaluate lodging risk more accurately than middle-stem (half plant height) or upper-stem (three quarters plant height) lodging indexes.

Camera trapping and spatially explicit capture–recapture for the monitoring and conservation management of lions: Insights from a globally important population in Tanzania

Abstract Accurate and precise estimates of population status are required to inform and evaluate conservation management and policy interventions. Although the lion (Panthera leo) is a charismatic species receiving increased conservation attention, robust status estimates are lacking for most populations. While for many large carnivores population density is often estimated through spatially explicit capture–recapture (SECR) applied to camera trap data, the lack of pelage patterns in lions has limited the application of this technique to the species. Here, we present one of the first applications of this methodology to lion, in Tanzania's Ruaha‐Rungwa landscape, a stronghold for the species for which no empirical estimates of status are available. We deployed four camera trap grids across habitat and land management types, and we identified individual lions through whisker spots, scars and marks, and multiple additional features. Double‐blind identification revealed low inter‐observer variation in photo identification (92% agreement), due to the use of xenon‐flash cameras and consistent framing and angles of photographs. Lion occurred at highest densities in a prey‐rich area of Ruaha National Park (6.12 ± SE 0.94 per 100 km2), and at relatively high densities (4.06 ± SE 1.03 per 100 km2) in a community‐managed area of similar riparian‐grassland habitat. Miombo woodland in both photographic and trophy hunting areas sustained intermediate lion densities (1.75 ± SE 0.62 and 2.25 ± SE 0.52 per 100 km2, respectively). These are the first spatially explicit density estimates for lion in Tanzania, including the first for a trophy hunting and a community‐managed area, and also provide some of the first insights into lion status in understudied miombo habitats. We discuss in detail the methodology employed, the potential for scaling‐up over larger areas, and its limitations. We suggest that the method can be an important tool for lion monitoring and explore the implications of our findings for lion management.

ОПРЕДЕЛЕНИЕ ПЕРЕМЕННОЙ ПЛОТНОСТИ ПРОМЕЖУТОЧНОГО СЛОЯ НА ГУБАХИНСКОМ УЧАСТКЕ (ПЕРМСКИЙ КРАЙ)

Because of the improvement of instrumentation and technology progress in the conducting of gravity survey, there is a continuous increase in the accuracy of calculating the gravity Bouguer anomalies. At the same time, due to inadequate assessment of the intermediate layer density taken as a constant for reduction, the calculated anomalies may contain significant relative error. The article describes the experience of using the three-point formula of V.M. Berezkin to build a map of the areal distribution of the density of the intermediate layer and calculating, on its basis, anomalies in the Bouguer reduction according to high-precision gravimetric surveys at the Gubakha area.

Growth and division mode plasticity is dependent on cell density in marine-derived black yeasts.

The diversity and ecological contribution of the fungus kingdom in the marine environment remain understudied. A recent survey in the Atlantic (Woods Hole, MA, USA) brought to light the diversity and unique biological features of marine fungi. The study revealed that black yeast species undergo an unconventional cell division cycle, which has not been documented in conventional model yeast species such as Saccharomyces cerevisiae (budding yeast) and Schizosaccharomyces pombe (fission yeast). The prevalence of this unusual property is unknown. Here, I collected and identified 65marine fungi species across 40genera from the surface ocean water, sediment, and the surface of macroalgae (seaweeds) in the Pacific (Sugashima, Toba, Japan). The Sugashima collection largely did not overlap with the Woods Hole collection and included several unidentifiable species, further illustrating the diversity of marine fungi. Three black yeast species were isolated, two of which were commonly found in Woods Hole (Aureobasidium pullulans and Hortaea werneckii). Surprisingly, their cell division mode was dependent on cell density, and the previously reported unconventional division mode was reproduced only at a certain cell density. For all three black yeast species, cells underwent filamentous growth with septations at low cell density and immediately formed buds at high cell density. At intermediate cell density, two black yeasts (H.werneckii and an unidentifiable species) showed rod cells undergoing septation at the cell equator. In contrast, all eight budding yeast species showed a consistent division pattern regardless of cell density. This study suggests the plastic nature of the growth/division mode of marine-derived black yeast.

(Pro)renin Receptor Inhibition Reduces Plasma Cholesterol and Triglycerides but Does Not Attenuate Atherosclerosis in Atherosclerotic Mice.

Objective: Elevated plasma cholesterol concentrations contributes to ischemic cardiovascular diseases. Recently, we showed that inhibiting hepatic (pro)renin receptor [(P)RR] attenuated diet-induced hypercholesterolemia and hypertriglyceridemia in low-density lipoprotein receptor (LDLR) deficient mice. The purpose of this study was to determine whether inhibiting hepatic (P)RR could attenuate atherosclerosis.Approach and Results: Eight-week-old male LDLR−/− mice were injected with either saline or N-acetylgalactosamine-modified antisense oligonucleotides (G-ASOs) primarily targeting hepatic (P)RR and were fed a western-type diet (WTD) for 16 weeks. (P)RR G-ASOs markedly reduced plasma cholesterol concentrations from 2,211 ± 146 to 1,128 ± 121 mg/dL. Fast protein liquid chromatography (FPLC) analyses revealed that cholesterol in very low-density lipoprotein (VLDL) and intermediate density lipoprotein (IDL)/LDL fraction were potently reduced by (P)RR G-ASOs. Moreover, (P)RR G-ASOs reduced plasma triglyceride concentrations by more than 80%. Strikingly, despite marked reduction in plasma lipid concentrations, atherosclerosis was not reduced but rather increased in these mice. Further testing in ApoE−/− mice confirmed that (P)RR G-ASOs reduced plasma lipid concentrations but not atherosclerosis. Transcriptomic analysis of the aortas revealed that (P)RR G-ASOs induced the expression of the genes involved in immune responses and inflammation. Further investigation revealed that (P)RR G-ASOs also inhibited (P)RR in macrophages and in enhanced inflammatory responses to exogenous stimuli. Moreover, deleting the (P)RR in macrophages resulted in accelerated atherosclerosis in WTD fed ApoE−/− mice.Conclusion: (P)RR G-ASOs reduced the plasma lipids in atherosclerotic mice due to hepatic (P)RR deficiency. However, augmented pro-inflammatory responses in macrophages due to (P)RR downregulation counteracted the beneficial effects of lowered plasma lipid concentrations on atherosclerosis. Our study demonstrated that hepatic (P)RR and macrophage (P)RR played a counteracting role in atherosclerosis.

Assessing the Electrochemical Performance of Different Nanostructured CeO2 Samples as Anodes for Lithium-Ion Batteries

In this work, six samples of CeO2 are successfully prepared by diverse synthesis routes leading to different microstructures regarding both morphology and particle size. The structural and microstructural characteristics presented by the samples and their influence on the electrochemical response of the prepared anodes are analyzed. In particular, the Ce-CMK3 sample, synthesized from a mesoporous carbon obtained through a CMK3 silica template, displays an enhanced electrochemical response. Thus, capacity values of ~220 mA h g−1 are obtained at a current rate of 0.155 A g−1 after 50 cycles and an excellent cyclability at intermediate current densities. On the other hand, it is observed that the capacity values are satisfactorily recovered at 0.31 A g−1, displaying ~100 mA h g−1 after 550 cycles and efficiencies close to 100%. The electrochemical performance is interpreted considering the microstructural peculiarities of this anode, which are deeply analyzed.

Influence of the heating rate on sintering shrinkage of plain iron

ABSTRACT The effect of heating rate on shrinkage of plain iron was investigated on green specimens with different green densities: 6.5, 6.9 and 7.3 g cm−3. On increasing the heating rate, the anisothermal shrinkage in the alpha field starts at higher temperatures but its amount does not change. The activation energy corresponds to that of dislocation pipe diffusion, confirming the role of the structural defects accumulated in the particles during cold compaction. The isothermal shrinkage increases on increasing the heating rate, likely due to the effect of surface diffusion at lower temperatures that reduce the driving force, without a measurable effect on shrinkage. The effect of green density is the same for anisothermal and isothermal shrinkage, with a minimum (in absolute value) at the intermediate green density.

Density aggregation operators for interval-valued q-rung orthopair fuzzy numbers and their application in multiple attribute decision making

The symmetry between fuzzy evaluations and crisp numbers provides an effective solution to multiple attribute decision making (MADM) problems under fuzzy environments. Considering the effect of information distribution on decision making, a novel approach to MADM problems under the interval-valued q-rung orthopair fuzzy (Iq-ROF) environments is put forward. Firstly, the clustering method of interval-valued q-rung orthopair fuzzy numbers (Iq-ROFNs) is defined. Secondly, Iq-ROF density weighted arithmetic (Iq-ROFDWA) intermediate operator and Iq-ROF density weighted geometric average (Iq-ROFDWGA) intermediate operator are developed based on the density weighted intermediate operators for crisp numbers. Thirdly, combining the density weighted intermediate operators with the Iq-ROF weighted aggregation operators, Iq-ROF density aggregation operators including Iq-ROF density weighted arithmetic (Iq-ROFDWAA) aggregation operator and Iq-ROF density weighted geometric (Iq-ROFDWGG) aggregation operator are proposed. Finally, effectiveness of the proposed method is verified through a numerical example.

Lightning threats in Nepal: occurrence and human impacts

Nepal has a very large topographical variation; this elevation change has a major influence on lightning occurrence and human casualties. The Himalayan peaks cover the northern part of Nepal with low population density, the middle is covered by hills with intermediate density, and the southern plain with the greatest density. This study will leverage lightning detection by Vaisala’s Global Lightning Dataset GLD360 network with a recent detailed compilation of lightning casualties from 2011 through 2020. Over one million lightning strokes per year were detected from 2016 through 2020. Stroke density is least over high elevations to the north, moderate in hilly regions, and very frequent over the south. The thunderstorm season begins in March and ceases by August after the annual monsoon cycle. Of all the natural disasters, lightning has been recorded to be the second highest killer after earthquakes. The Ministry of Home Affairs reports an average of 103 lightning deaths per year. The fatality rate of 3.8 deaths million−1 year−1 is highest among the South Asian countries. Fatalities over high mountains are rare, with most casualties over the center of Nepal. Lightning Fatality Risk is not a good indicator of the fatalities that occur in a district.

Chiral condensates for neutron stars in hadron-quark crossover: From a parity doublet nucleon model to a Nambu–Jona-Lasinio quark model

We study the chiral condensates in neutron star matter from nuclear to quark matter domain. We describe nuclear matter with a parity doublet model (PDM), quark matter with the Nambu--Jona-Lasino (NJL) model, and a matter at the intermediate density by interpolating nuclear and quark matter equations of state. The model parameters are constrained by nuclear physics and neutron star observations. Various condensates in the interpolated domain are estimated from the chemical potential dependence of the condensates at the boundaries of the interpolation. The use of the PDM with substantial chiral invariant mass ($m_0 \gtrsim 500$ MeV, which is favored by the neutron star observations) predicts the mild chiral restoration, and the significant chiral condensate remains to baryon density $n_B \sim 2-3n_0$ ($n_0\simeq 0.16\,{\rm fm}^{-3}$: nuclear saturation density), smoothly approaching the NJL predictions for the color-flavor-locked phase at $n_B \gtrsim 5n_0$. The same method is applied to estimate diquark condensates, number densities of up-, down- and strange-quarks, and the lepton fraction. In our descriptions the chiral restoration in the interpolated domain proceeds with two conceptually distinct chiral restoration effects; the first is associated with the positive scalar density in a nucleon, relevant in dilute regime, and the other primarily arises from the modification of the quark Dirac sea, which is triggered by the growth of the quark Fermi sea. We discuss several qualitative conjectures to interpolate the microphysics in nuclear and quark matter.