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While closing their famous paper entitled "Pseudogap: friend or foe of high-Tc?" Norman, Pines, and Kallin underlined that before we have a microscopic theory, we must have a consistent phenomenology. This was in 2005. As it turns out in 2006, a phenomenological theory of the pseudogap state was proposed by Gor'kov and Teitel'baum. This originated from their careful analysis of the Hall effect data, and it has been very successful model as numerous investigations over the years have shown. In this mini-review, the essence of the idea of Gor'kov and Teitel'baum is presented. The pseudogap obtained by them from the Hall effect data agrees very well with that obtained from the ARPES data. This famous Gor'kov–Teitel'baum thermal activation model (in short GTTA model) not only presents a consistent phenomenology of the pseudogap state, but also rationalizes the Hall angle data, and it presents a strong case against the famous "two-relaxation times" idea of Anderson and collaborators. [ABSTRACT FROM AUTHOR]

As is well known, Paul Drude put forward the very first quantitative theory of electrical conduction in metals in 1900. He could successfully account for the Wiedemann–Franz law which states that the ratio of thermal to electrical conductivity divided by temperature is a constant called the Lorenz number. As it turns out, in Drude's derivation there is a lucky cancellation of two errors. Drude's underestimatation (by an order of 100) of the value of square of the average electron velocity compensated for his overestimatation of the electronic heat capacity (by the same order of 100). This compensation or cancellation of two errors lead to a value of the Lorenz number very close to its experimental value; which is well known. There is another error of a factor of two which Drude made when he calculated two different relaxation times for heat conductivity and electrical conductivity; in this article we highlight how and why this error occurred in Drude's derivation and how it was removed 5 years later (in 1905) by Hendrik Lorentz when he used the Boltzmann equation and a single relaxation time. This article is of pedagogical value and may be useful to undergraduate/graduate students learning solid state physics. [ABSTRACT FROM AUTHOR]

Partial migration, whereby a proportion of a population migrates between distinct seasonal ranges, is common throughout the animal kingdom. However, studies linking existing theoretical models of migration probability, with empirical data are lacking. The competitive release hypothesis for partial migration predicts that due to density‐dependent habitat selection, the proportion of migrants increases as the relative quality and size of the seasonal range increases, but decreases with increasing migration cost and population density. To test this prediction, we developed a quantitative framework to predict the proportion of migrants, using empirical data from 545 individually GPS‐marked moose Alces alces from across Fennoscandia, spanning latitudes of 56° to 68°N. Moose contracted their ranges to common and spatially limited winter areas (typically at lower elevation), but expanded them during summer due to an increase in suitable habitat (at highland ranges). As predicted from our model, a better and larger highland range relative to the lowland range corresponded to a higher proportion of migrants in an area. Quantitative predictions coupling the balance of habitat availability of seasonal ranges with the probability of migrating in a large herbivore is a necessary step towards an enhanced understanding of the mechanisms underlying migration at the population level. [ABSTRACT FROM AUTHOR]

Aim: Animal migrations influence ecosystem structure, dynamics and persistence of predator and prey populations. The theory of migratory coupling postulates that aggregations of migrant prey can induce large‐scale synchronized movements in predators, and this coupling is consequential for the dynamics of ecological communities. The degree to which humans influence these interactions remains largely unknown. We tested whether creation of large resource pulses by humans such as seasonal herding of reindeer Rangifer tarandus and hunting of moose, Alces alces, can induce migratory coupling with Golden Eagles, Aquila chrysaetos, and whether these lead to demographic consequences for the eagles. Location: Fennoscandia. Methods: We used movement data from 32 tracked Golden Eagles spanning 125 annual migratory cycles over 8 years. We obtained reindeer distribution data through collaboration with reindeer herders based on satellite tracking of reindeer, and moose harvest data from the national hunting statistics for Sweden. We assessed demographic consequences for eagles from ingesting lead from ammunition fragments in moose carcasses through survival estimates and their links with lead concentrations in eagles' blood. Results: In spring, eagles migrated hundreds of kilometres to be spatially and temporally coupled with calving reindeer, whereas in autumn, eagles matched their distribution with the location and timing of moose hunt. Juveniles were more likely to couple with reindeer calving, whereas adults were particularly drawn to areas of higher moose harvest. Due to this coupling, eagles ingested lead from spent ammunition in moose offal and carcasses and the resulting lead toxicity increased the risk of mortality by 3.4 times. Main conclusions: We show how migratory coupling connects landscape processes and that human actions can influence migratory coupling over large spatial scales and increase demographic risks for predators. We provide vital knowledge towards resolving human–wildlife conflicts and the conservation of protected species over a large spatial and temporal scale. [ABSTRACT FROM AUTHOR]

Diminishing wild space and population fragmentation are key drivers of large carnivore declines worldwide. The persistence of large carnivores in fragmented landscapes often depends on the ability of individuals to move between separated subpopulations for genetic exchange and recovery from stochastic events. Where separated by anthropogenic landscapes, subpopulations' connectivity hinges on the area's socio-ecological conditions for coexistence and dispersing individuals' behavioral choices. Using GPS-collars and resource- and step-selection functions, we explored African lion (Panthera leo) habitat selection and movement patterns to better understand lions' behavioral adjustments in a landscape shared with pastoralists. We conducted our study in the Ngorongoro Conservation Area (NCA), Tanzania, a multiuse rangeland, that connects the small, high density lion subpopulation of the Ngorongoro Crater with the extensive Serengeti lion population. Landscape use by pastoralists and their livestock in the NCA varies seasonally, driven by the availability of pasture, water, and disease avoidance. The most important factor for lion habitat selection was the amount of vegetation cover, but its importance varied with the distance to human settlements, season and time of day. Although we noted high levels of individual variation in tolerance for humans, in general lions avoided humans on the landscape and used more cover when closer to humans. Females showed more consistent avoidance of humans and stronger use of cover when near humans than did males. Connectivity of lion subpopulations does not appear to be blocked by sparse pastoralist settlements, and nomadic males, key to subpopulation connectivity, significantly avoided humans during the day, suggesting a behavioral strategy for conflict mitigation. These results are consistent with lions balancing risk from humans with exploitation of livestock by altering their behaviors to reduce potential conflict. Our study lends some optimism for the adaptive capacity of lions to promote coexistence with humans in shared landscapes. [ABSTRACT FROM AUTHOR]

Animal migration has fascinated scientists and the public alike for centuries, yet migratory animals are facing diverse threats that could lead to their demise. The Anthropocene is characterised by the reality that humans are the dominant force on Earth, having manifold negative effects on biodiversity and ecosystem function. Considerable research focus has been given to assessing anthropogenic impacts on the numerical abundance of species/populations, whereas relatively less attention has been devoted to animal migration. However, there are clear linkages, for example, where human‐driven impacts on migration behaviour can lead to population/species declines or even extinction. Here, we explore anthropogenic threats to migratory animals (in all domains – aquatic, terrestrial, and aerial) using International Union for the Conservation of Nature (IUCN) Threat Taxonomy classifications. We reveal the diverse threats (e.g. human development, disease, invasive species, climate change, exploitation, pollution) that impact migratory wildlife in varied ways spanning taxa, life stages and type of impact (e.g. from direct mortality to changes in behaviour, health, and physiology). Notably, these threats often interact in complex and unpredictable ways to the detriment of wildlife, further complicating management. Fortunately, we are beginning to identify strategies for conserving and managing migratory animals in the Anthropocene. We provide a set of strategies that, if embraced, have the potential to ensure that migratory animals, and the important ecological functions sustained by migration, persist. [ABSTRACT FROM AUTHOR]

An introduction to the Zwanzig–Mori–Götze–Wölfle memory function formalism (or generalized Drude formalism) is presented. This formalism is used extensively in analyzing the experimentally obtained optical conductivity of strongly correlated systems such as cuprates and iron-based superconductors. For a broader perspective both the generalized Langevin equation approach and the projection operator approach for the memory function formalism are given. The Götze–Wölfle perturbative expansion of memory function is presented and its application to the computation of the dynamical conductivity of metals is also reviewed. This digest of the formalism contains all the mathematical details for pedagogical purposes. [ABSTRACT FROM AUTHOR]

We report a comparative study of scattering rates which are calculated using different formalisms such as [P. B. Allen, Phys. Rev. B 3, 305 (1971); S. V. Shulga, D. V. Dolgov and E. G. Maksimov, Physica C 178, 266 (1991); B. Mitrović and M. A. Fiorucci, Phys. Rev. B 31, 2694 (1985); S. G. Sharapov and J. P. Carbotte, Phys. Rev. B 72, 134506 (2005)] and memory function formalism (MemF) [H. Mori, Prog. Theor. Phys. 33, 423 (1965)]. An advantage of this study is that it sheds light on the physical assumptions used in these formalisms. In this context, we consider a case of electron–phonon interaction and discuss frequency- and temperature-dependent behavior of scattering rates. Further, a comparative study of scattering rate proceeds for distinct phonon density of states (PDOS) and electron density of states (EDOS). From the detailed analysis, we observe that the MemF is the most general one and others are based on restrictive assumptions as discussed in this work. [ABSTRACT FROM AUTHOR]

Highlights • In a resonant AC field, we uncover a new channel of momentum relaxation. An additional resistivity is predicted. • Study of Electro-magneto Resistance using the Drude theory. • An extension of Einstein's derivation of equilibrium Planckian formula to near equilibrium systems. Abstract We extend the well known phenomenon of magnetoresistance (extra resistivity of materials in transverse magnetic field) to a regime where in addition to a transverse magnetic field, a transverse microwave field of resonant frequency is also applied. In a magnetic field, electron spin levels are Zeeman split. In a resonant microwave field, we uncover a new channel of momentum relaxation in which electrons in upper Zeeman level can deexcite to lower Zeeman level by generating spin fluctuation excitation in the lattice (similar to what happens in Electron Spin Resonance (ESR) spectroscopy). An additional resistivity due to this mechanism is predicted in which momentum randomization of Zeeman split electrons happen via bosonic excitations (spin fluctuations). An order of magnitude of this additional resistivity is calculated. The whole work is based upon an extension of Einstein's derivation of equilibrium Planckian formula to near equilibrium systems. [ABSTRACT FROM AUTHOR]

The conservation and management of mobile species, populations and dynamic habitats, presents significant challenges since such species face diverse threats during various stages of their life cycle. Protected areas (PAs) are essential tools in conservation efforts, aiming to preserve native species and their habitats. However, larger mobile animals, such as the Bonelli's eagle (Aquila fasciata), may require much larger areas outside PAs for essential life moments, including foraging, resting, and wintering. As a result, the efficacy of PAs in conserving such species may be questionable. We designed an experiment in an eastern Spain PA that is home to nesting Bonelli's eagles to determine if increasing food availability through experimental feeding within the PA could result in an effective reduction of space use outside the protected area by the eagles and lead to reduce death risk. Over the period of 2016 to 2021, we tracked 10 Bonelli's eagles from six different territories using GPS-GSM transmitters. We evaluated their space use before, during, and after the feeding experiment. Our results indicate that the availability of food within PAs restricted the eagles' movement, resulting in a higher concentration of locations inside the PAs. The eagles spent less time outside the PAs when they were fed and less time in highly human-dominated habitats. Consequently, this reduced mortality risks that were higher outside the PAs. Our findings suggest that management decisions aimed at increasing food availability within PAs, could be critical in conserving endangered species populations such as the Bonelli's eagle in Mediterranean landscapes. [Display omitted] • Availability of food within PAs restricted the eagles' movement. • Eagles spent less time on human-dominated habitats when they were fed. • Increasing food availability within PAs could improve its role in conservation. • Improving natural prey populations could be the key of predators' conservation. • Several predator endangered species can benefit from this PAs management. [ABSTRACT FROM AUTHOR]

Lead poisoning of animals due to ingestion of fragments from lead-based ammunition in carcasses and offal of shot wildlife is acknowledged globally and raises great concerns about potential behavioral effects leading to increased mortality risks. Lead levels in blood were correlated with progress of the moose hunting season. Based on analyses of tracking data, we found that even sublethal lead concentrations in blood (25 ppb, wet weight), can likely negatively affect movement behavior (flight height and movement rate) of free-ranging scavenging Golden Eagles (Aquila chrysaetos). Lead levels in liver of recovered post-mortem analyzed eagles suggested that sublethal exposure increases the risk of mortality in eagles. Such adverse effects on animals are probably common worldwide and across species, where game hunting with lead-based ammunition is widespread. Our study highlights lead exposure as a considerably more serious threat to wildlife conservation than previously realized and suggests implementation of bans of lead ammunition for hunting. [ABSTRACT FROM AUTHOR]

We consider nonequilibrium relaxation of electrons due to their coupling with phonons in a simple metal. In our model, electrons are living at a higher temperature than that of the phonon bath, mimicking a nonequilibrium steady-state situation. We study the relaxation of such hot electrons proposing a suitable generalization of the memory function formalism formulated by Götze and Wölfle (GW) [W. Götze and P. Wölfle, Phys. Rev. B 6, 1226 (1972)]. We derive analytical expressions for both the DC or zero frequency scattering rates and the optical scattering rates in various temperature and frequency regimes. Limiting cases are in accord with the previous studies. An interesting feature that the DC scattering rate at high temperatures and optical scattering rate at high frequencies are independent of the temperature difference between the electrons and the phonons is found in this study. The present formalism forms a basis which can also be extended to study hot-electron relaxation in variety of complex materials. [ABSTRACT FROM AUTHOR]

Estimating migration parameters of individuals and populations is vital for their conservation and management. Studies on animal movements and migration often depend upon location data from tracked animals and it is important that such data are appropriately analyzed for reliable estimates of migration and effective management of moving animals. The Net Squared Displacement (NSD) approach for modelling animal movement is being increasingly used as it can objectively quantify migration characteristics and separate different types of movements from migration. However, the ability of NSD to properly classify the movement patterns of individuals has been criticized and issues related to study design arise with respect to starting locations of the data/animals, data sampling regime and extent of movement of species. We address the issues raised over NSD using tracking data from 319 moose (Alces alces) in Sweden. Moose is an ideal species to test this approach, as it can be sedentary, nomadic, dispersing or migratory and individuals vary in their extent, timing and duration of migration. We propose a two-step process of using the NSD approach by first classifying movement modes using mean squared displacement (MSD) instead of NSD and then estimating the extent, duration and timing of migration using NSD. We show that the NSD approach is robust to the choice of starting dates except when the start date occurs during the migratory phase. We also show that the starting location of the animal has a marginal influence on the correct quantification of migration characteristics. The number of locations per day (1–48) did not significantly affect the performance of non-linear mixed effects models, which correctly distinguished migration from other movement types, however, high-resolution data had a significant negative influence on estimates for the timing of migrations. The extent of movement, however, had an effect on the classification of movements, and individuals undertaking short- distance migrations can be misclassified as other movements such as sedentary or nomadic. Our study raises important considerations for designing, analysing and interpreting movement ecology studies, and how these should be determined by the biology of the species and the ecological and conservation questions in focus. [ABSTRACT FROM AUTHOR]

Impurity induced low temperature upturns in both the ab -plane and the c -axis dc-resistivities of cuprates in the pseudogap state have been observed in experiments. We provide an explanation of this phenomenon by incorporating impurity scattering of the charge carriers within a phenomenological model proposed by Yang, Rice and Zhang. The scattering between charge carriers and the impurity atom is considered within the lowest order Born approximation. Resistivity is calculated within Kubo formula using the impurity renormalized spectral functions. Using physical parameters for cuprates, we describe qualitative features of the upturn phenomena and its doping evolution that coincides with the experimental findings. We stress that this effect is largely due to the strong electronic correlations. [ABSTRACT FROM AUTHOR]

Background: Despite centuries of research, debate remains on the scaling of metabolic rate to mass especially for intraspecific cases. The high variation of body mass within brown bears presents a unique opportunity to study the intraspecific effects of body mass on physiological variables. The amplitude of metabolic rate reduction in hibernators is dependent on body mass of the species. Small hibernators have high metabolic rates when euthermic but experience a drastic decrease in body temperature during torpor, which is necessary to reach a very low metabolic rate. Conversely, large hibernators, such as the brown bear (Ursus arctos), show a moderate decrease in temperature during hibernation, thought to be related to the bear's large size. We studied body mass, abdominal body temperature, heart rate, and accelerometer-derived activity from 63 free-ranging brown bears (1–15 years old, 15–233 kg). We tested for relationships between body mass and body temperature, heart rate, and hibernation duration. Results: The smallest individuals maintained lower body temperatures during hibernation, hibernated longer, and ended hibernation later than large bears. Unlike body temperature, winter heart rates were not associated with body mass. In summer, the opposite pattern was found, with smaller individuals having higher body temperature and daytime heart rates. Body mass was associated with body temperature in the winter hypometabolic state, even in a large hibernating mammal. Smaller bears, which are known to have higher thermal conductance, reached lower body temperatures during hibernation. During summer, smaller bears had higher body temperatures and daytime heart rates, a phenomenon not previously documented within a single mammalian species. Conclusion: We conclude that the smallest bears hibernated more deeply and longer than large bears, likely from a combined effect of basic thermodynamics, the higher need for energy savings, and a lower cost of warming up a smaller body. [ABSTRACT FROM AUTHOR]

Monitoring of species and their ecosystem attributes is a fundamental requirement in applied ecology and conservation. However, landscape scale monitoring requires an immense effort and commitment, especially when species have a wide distribution or are migratory in nature. Participatory monitoring, whereby local communities are engaged, is increasingly being proposed to address landscape scale monitoring. Its implementation is met with many challenges related to finances, motivation of the local people, lack of trained manpower, and nondirect legal use of the species in question. It is of interest to determine what makes a participatory monitoring program interesting for locals to ensure their long term engagement. Using the unique 26-year program of hunters' observations of moose (Alces alces) in Sweden as a case study, we present the evolution of this highly successful participatory monitoring program and show that tackling the motivation to monitor, early involvement of local NGOs, social activities revolving around use of the resource, the biology and economic value of the species, and technical and practical aspects related to the monitoring, together create a successful participatory monitoring program. When users benefit directly from the resource, participate in conservation/management decision making, socialize with other participants, and get rewards for their commitment and effective monitoring, participatory monitoring schemes can then become rewarding and sustainable. [ABSTRACT FROM AUTHOR]

We report the results of a theoretical investigation on charge dynamics in weakly coupled CuO 2 planes of the cuprate Ca 2 − x Na x CuO 2 Cl 2 in the pseudogap regime by using the theory of Yang, Rice, and Zhang (YRZ) [1] . With a detailed numerical analysis at various impurity scattering rates ( γ imp ), we observe that YRZ model is not able to reproduce (in magnitude) the experimentally observed frequency evolution of optical conductivity at a fixed doping level. Further, to analyze the doping evolution, we have done a detailed comparison of calculated YRZ conductivity with the experimental one using Two-Component Drude–Lorentz model. We find that YRZ model is capable of reproducing ( qualitatively ) the experimentally observed doping evolution of Drude processes (low energy scale) and processes at the pseudogap (intermediate energy scale). We also discuss physical reasons of the discrepancy seen in magnitudes. [ABSTRACT FROM AUTHOR]

Partial migration, whereby a proportion of the population migrates, is common across the animal kingdom. Much of the focus in the literature has been on trying to explain the underlying mechanisms for the coexistence of migrants and residents. In addition, there has been an increasing number of reports on the prevalence and frequency of partially migratory populations. One possible explanation for the occurrence of partial migration, which has received no attention in the literature, is that of ‘transient coexistence’ during the invasion phase of a superior behaviour. In this study we develop a theoretical basis for explaining partial migration as a transient coexistence and derive a method to predict the frequency of residents and migrants in partially migrating populations. This method is useful to predict the frequencies of migrants and residents in a small set of populations as a complementing hypothesis to ‘an Evolutionary Stable Strategy (ESS)’. We use the logistic growth equation to derive a formula for predicting the frequencies of residents and migrants. We also use simulations and empirical data from white perch (Morone americana), moose (Alces alces) and red deer (Cervus elaphus) to demonstrate our approach. We show that the probability of detecting partial migration due to transient coexistence depends upon a minimum number of tracked or marked individuals for a given number of populations. Our approach provides a starting point in searching for explanations to the observed frequencies, by contrasting the observed pattern with both the predicted transient and the uniform random pattern. Aggregating such information on observed patterns (proportions of migrants and residents) may eventually lead to the development of a quantitative theory for the equilibrium (ESS) populations as well. [ABSTRACT FROM AUTHOR]

Gynaecological cancers continue to present a significant health burden upon the health of the global female population. This deficit is most prominent with ovarian cancer which possesses the lowest survival rate compared to all other cancers occurring within this anatomical region, with an annual UK-mortality of 7,300. The poor tolerability and selectively of the treatment options that are currently available is likely to have contributed to this high mortality rate thus, demonstrating the need for the development of enhanced therapeutic approaches. Aptamer technology would involve the engineering of specifically sequenced oligonucleotide chains, which bind to macromolecular targets with a high degree of affinity and selectively. Recent in-vitro studies conducted upon the clinical utility of this technique have supported its superiority in targeting individual therapeutic drug targets compared to various other targeting moieties currently within therapeutic use such as, monoclonal antibodies. For this reason, the employment of this technique is likely to be favourable in reducing the incidence of non-specific, chemotherapy-associated adverse effects. Kisspeptin is a naturally expressed polypeptide with an established role in the development of the reproductive system and other proposed roles in influencing the ability of ovarian cancer growths to exhibit the metastasis hallmark. This distinctive feature would indicate the potential for the manipulation of this pathway through the application of aptamer structures in developing a novel prophylactic strategy and improve the long-term outcome for ovarian cancer patients. [ABSTRACT FROM AUTHOR]

This work is dedicated to those who are genuinely interested in the foundations of statistical mechanics. Statistical mechanics is a very successful theory. The foundations on which it is based are radically different from the foundations of Newtonian mechanics. Probability and the law of large numbers are its fundamental ingredients. In this paper we will see how the statistical mechanical synthesis which incorporates mechanics (deterministic) and probability theory (indeterministic) works. The approach consists of replacing the actual system by a hypothetical ensemble of systems under same external conditions. From the most used prescription of Gibbs, we calculate the phase space averages of dynamical quantities and find that these phase averages agree very well with experiments. Clearly, actual experiments are not done on a hypothetical ensemble. They are done on the actual system in the laboratory and these experiments take a finite amount of time. Thus, it is usually argued that actual measurements are time averages and they are equal to phase averages due to ergodic hypothesis (time averages = phase space averages). The aim of the present review is to show that ergodic hypothesis is not relevant for equilibrium statistical mechanics (with Tolman and Landau). We will see that the solution for the problem is in the very peculiar nature of the macroscopic observables and with a very large number of degrees of freedom involved in macroscopic systems as first pointed out by Boltzmann and then more quantitatively by Khinchin. Similar arguments were used by Landau based upon the approximate property of "statistical independence". We analyze these ideas in detail. We present a critique of the ideas of Jaynes who says that the ergodic problem is a conceptual one and is related to the very concept of ensemble itself which is a by-product of the frequency theory of probability, and the ergodic problem becomes irrelevant when the probabilities of various microstates are interpreted with Laplace-Bernoulli Theory of Probability (Bayesian viewpoint). At the end, we critically review various quantum approaches (quantum-statistical typicality approaches) to the foundations of statistical mechanics. The literature on quantum-statistical typicality is organized under four notions (i) kinematical canonical typicality, (ii) dynamical canonical typicality, (iii) kinematical normal typicality, and (iv) dynamical normal typicality. Analogies are seen in the Khinchin's classical approach and in the modern quantum-statistical typicality approaches. [ABSTRACT FROM AUTHOR]

India, a mega-diverse country in terms of both biodiversity and people, is battling environmental problems on many fronts: chronic dependence on natural resources, dwindling ecosystem services, declining environmental quality, effects of climate change and a biodiversity crisis., We review the current focal areas and infrastructure for ecological research and education in India, along with the surrounding legal and policy aspects of related socio-economic issues., Currently, ecological and applied research is predominantly focused on charismatic species within protected areas. This scope could be broadened beyond organismal biology towards functional landscapes and ecosystems; the education system also needs to promote ecology as a career choice for scientists. Expectedly, many environmental challenges are generic in nature, occur in other regions of the world, are primarily biophysical in origin but extend into human dimensions; some challenges are socio-political and have implications for biodiversity conservation., Synthesis and applications. India's environmental concerns include, but are not restricted to, the biodiversity crisis. The biodiversity crisis, in turn, includes, but is not restricted to, the most charismatic species. Greater integration and alignment among the mandates of government agencies, scientists, policymakers and educators are needed to meet contemporary environmental issues. [ABSTRACT FROM AUTHOR]

An efficient numerical algorithm for solving the time-non-local non-Markovian master equation in the second Born approximation with exponentially decaying bath correlation function is introduced. Specifically, the coupled integro-differential equations for the reduced density matrix are solved by an efficient auxiliary function method in both the energy and site representations. As an application we consider the traditional dimer system that is used to model excitation energy transfer in photosynthetic systems, examining exact second order results and using them to assess the range of validity of the traditional Markov approximation. The method is also used to examine the dependence of the dynamics on the initial coherences in the case of two coupled oscillators. The computational results are augmented by a set of analytic inequalities obtained for the regime of validity of the Markov approximation in the cases of weak and strong resonance coupling, allowing for a rapid determination of the utility of the Markovian dynamics in various parameter regions. [ABSTRACT FROM AUTHOR]

Conservation of declining migratory species is a challenging task, as the factors that may have determined their past distribution may not determine their current and future distribution. Saiga antelope Saiga tatarica populations have massively declined due to poaching. The species is now beginning to recover in Kazakhstan and protected areas are being implemented. Using 25 years of aerial monitoring data, we identified changes in the spring distribution and predicted densities of saiga to prioritize areas for protection under scenarios of climate change together with changes in disturbance and population size. Conserving the spring distribution is critical as spring calving aggregations are of particular importance to population viability. The current distribution is strongly influenced by disturbance, whereas climate had a stronger influence in the past. The area of highly suitable habitat has halved and become fragmented in the last decade. The existing and proposed protected areas are relatively complementary and perform well under most scenarios of future change. However there is a need to widen the geographical scope of protected area planning if potential future high suitability areas are to be effectively protected. Climate change interacts with other factors to determine the distribution of suitable habitat within and outside protected areas. Scenarios in which conservation has increased saiga population size and density tend to show limited impacts of climate change, while scenarios in which the saiga population fails to recover and disturbance continues show, worsening patchiness and reduced suitable habitat. Synthesis and applications. We provide evidence for changing distribution and density of a migratory species over a large spatio-temporal scale, and suggest that future distribution may be more constrained and spatially heterogeneous. These results have important implications for designing future conservation measures for migratory species, such that areas that robustly show high suitability under a range of potential scenarios of change can be included in protected area expansion plans. Protected area placement based only on current, rather than projected distribution risks wasting opportunities for proactive conservation, particularly for a highly disturbed, recovering species likely to be affected by climate change. [ABSTRACT FROM AUTHOR]

Asia’s rangelands and mountains are strongholds for several endemic ungulate species. Little is known about the ecology of these species because of the region’s remoteness and the lack of robust scientific studies. Hunting, habitat modification, increased livestock grazing, disease and development are the major threats to the species. There is an urgent need for better monitoring to identify the size, distribution and dynamics of the populations of these species, and the threats to them, for effective conservation. The feasibility of standard scientific monitoring is greatly influenced by the remoteness of the region, the pre-existing scientific ideology, lack of expertise in the latest monitoring methods and awareness of biases and errors, and low capacity and logistical and financial constraints. We review the existing methods used for monitoring ungulates, identify the practical and institutional challenges to effective monitoring in Central Asia and categorize the methods based on various criteria so that researchers can plan better monitoring studies suited to particular species. We illustrate these issues using examples from several contrasting ungulate species. We recommend that scientific surveys should be complemented by increases in participatory monitoring, involving local people. The future of ungulate monitoring in Central Asia lies in a better recognition of the existing errors and biases in monitoring programmes and methods, allocation of more monitoring effort in terms of manpower, finances and logistics, understanding of robust scientific methods and sampling theory, and changing the scientific culture, as well as a commitment to ensuring that we monitor the things that matter. [ABSTRACT FROM AUTHOR]

Hunting is a serious threat to wildlife worldwide. The rainforest-rich Arunachal Pradesh state of India, a biodiversity hotspot, is an area severely affected by indigenous hunting. The state has several indigenous tribes who hunt for food, trade, culture and leisure. Using semi-structured interviews and questionnaires we surveyed 184 individuals in 51 villages across four tribes for information on species hunted and hunting practices. A total of 33 mammalian species are reportedly hunted, of which only 11 were reported by hunters during formal interviews. The other 22 species were observed during casual visits, festivals and informal discussions. Of the species hunted 20 are Endangered, Vulnerable or Near Threatened on the IUCN Red List. Villagers now travel longer distances to hunt than they did a decade ago, suggesting a decline in wildlife populations around villages. The extent of offtake of mammals was related to the altitude of the village and the use of guns. Villagers living at higher altitudes and with guns appeared to hunt more. We also documented the importance of ritualistic hunting by some tribes. Additional research is required to estimate offtake and consumption rates of wild meat. Increasing conservation awareness and community-based conservation projects may assist in controlling the severity and extent of this hunting problem. [ABSTRACT FROM AUTHOR]

A non-Hermitean extension of paradigmatic Wishart random matrices is introduced to set up a theoretical framework for statistical analysis of (real, complex, and real-quaternion) stochastic time series representing two 'remote' complex systems. The first paper in a series provides a detailed spectral theory of non-Hermitean Wishart random matrices composed of complex valued entries. The great emphasis is placed on an asymptotic analysis of the mean eigenvalue density for which we derive, among other results, a complex-plane analog of the Marcˇenko-Pastur law. A surprising connection with a class of matrix models previously invented in the context of quantum chromodynamics is pointed out. [ABSTRACT FROM AUTHOR]

The present paper is a review of the phenomena related to nonequilibrium electron relaxation in bulk and nano-scale metallic samples. The workable Two-Temperature Model (TTM) based on Boltzmann–Bloch–Peierls kinetic equation has been applied to study the ultra-fast (femto-second) electronic relaxation in various metallic systems. The advent of new ultra-fast (femto-second) laser technology and pump-probe spectroscopy has produced wealth of new results for micro- and nano-scale electronic technology. The aim of this paper is to clarify the TTM, conditions of its validity and nonvalidity, its modifications for nano-systems, to sum-up the progress, and to point out open problems in this field. We also give a phenomenological integro-differential equation for the kinetics of nondegenerate electrons that goes beyond the TTM. [ABSTRACT FROM AUTHOR]

We study the fluctuations of work done and dissipated heat of a Brownian particle in a symmetric double well system. The system is driven by two periodic input signals that rock the potential simultaneously. Confinement in one preferred well can be achieved by modulating the relative phase between the drives. We show that in the presence of pumping the stochastic resonance signal is enhanced when analysed in terms of the average work done on the system per cycle. This is in contrast with the case when pumping is achieved by applying an external static bias, which degrades resonance. We analyse the nature of work and heat fluctuations and show that the steady state fluctuation theorem holds in this system. [ABSTRACT FROM AUTHOR]

Sexual segregation, a widely observed phenomenon in vertebrates, is commonly categorized into habitat and social segregation. A universal explanation for sexual segregation is, however, lacking and debated. Causes of segregation and their division into proximate and ultimate causes is also highly debated, and the relative contributions of habitat and social factors to segregation are also seldom quantified. We studied the Eurasian wild sheep in trans-Himalayan rangelands to identify these causes and estimate the contributions of habitat and social components to sexual segregation. We observed male, lactating, and nonlactating female groups feeding during 3 springs and summers. The 3 groups strongly segregated and differed in their activity budgets, partly because of antipredation risks, with lactating females being the most vigilant (40% of the time). At the feeding habitat scale, males selected the patches of highest quality. We found that the social component contributed the most to segregation (70%) as compared with habitat segregation (30%). This is the first study that quantifies the contribution of habitat and social components to sexual segregation. We emphasize the role of antipredator behavior of lactating females on activity budgets and selection of relatively poor-quality sites as compared with other groups and illustrate that the usual division into proximal and ultimate causes of sexual segregation is not as clear-cut as usually presented. [ABSTRACT FROM PUBLISHER]

Abstract: We extend one-dimensional asymmetric simple exclusion process (ASEP) to a surface and show that the effect of transverse diffusion is to induce a continuous phase transition from a constant density phase to a maximal current phase as the forward transition probability p is tuned. The signature of the non-equilibrium transition is evident in the finite size effects near the transition. The results are compared with similar couplings operative only at the boundary. It is argued that the nature of the phases can be interpreted in terms of the modifications of boundary layers. [Copyright &y& Elsevier]

We extend Tooru-Cohen analysis for nonequilibrium steady state (NSS) of a Brownian particle to nonequilibrium oscillatory state (NOS) of Brownian particle by considering time dependent external drive protocol. We consider an unbounded charged Brownian particle in the presence of oscillating electric field and prove work fluctuation theorem, which is valid for any initial distribution and at all times. For harmonically bounded and constantly dragged Brownian particle considered by Tooru and Cohen, work fluctuation theorem is valid for any initial condition (also NSS), but only in large time limit. We use Onsager-Machlup Lagrangian with a constraint to obtain frequency dependent work distribution function, and describe entropy production rate and properties of dissipation functions for the present system using Onsager-Machlup functional. [ABSTRACT FROM AUTHOR]

We revisit the problem of quantum diffusion of a particle moving on a lattice with dynamical disorder. Decoherence, essential for the diffusive motion, is introduced via a set of Lindblad operators, known to guarantee per se the positivity, Hermiticity and the trace-class nature of the reduced density matrix, are derived and solved analytically for several transport quantities of interest. For the special Hermitian choice of the Lindblad operators projected onto the lattice sites, we recover several known results, obtained by others, e.g. through the stochastic Liouville equation using phenomenological damping terms for the off-diagonal density-matrix elements. An interesting result that we obtained is for the case of a 1D lattice with static potential bias and a time-harmonic modulation (ac drive) of its transition-matrix element, where the diffusion coefficient shows an oscillatory behavior as function of the drive amplitude and frequency — clearly, a Wannier–Stark ladder signature. The question of dissipation is also briefly discussed. [ABSTRACT FROM AUTHOR]

The relaxation of hot electrons is considered in a metal nanoparticle. When the particle size is of the order of electron mean free path, the main channel of hot electron energy loss is through surface-phonon generation, rather than bulk phonon generation. A calculation for the hot electron relaxation by the generation of surface-phonons is given, assuming that electrons and surface-phonons are described by their equilibrium Fermi and Bose distribution functions. The assumption is valid because the time required to establish equilibrium in the electron gas is much less than the time for achieving equilibrium between the electrons and the surface-phonons. The expressions obtained for low-temperature and high-temperature regimes are inversely proportional to the radius of the particle. This shows that size dependency of electron surface-phonon energy exchange arises from the geometric effect. [ABSTRACT FROM AUTHOR]

A model calculation is given for the energy relaxation of a nonequilibrium distribution of hot electrons prepared in a metallic sample that has been subjected to homogeneous photo-excitation by a femtosecond laser pulse. The model assumes that the photoexcitation creates two interpenetrating electronic subsystems, initially comprising of a dilute energy-wise higher-lying nondegenerate hot electron subsystem, and a relatively dense, lower-lying electron subsystem which is degenerate. The relaxation process is taken to be dominated by the electron–(multi)phonon interaction, resulting in a quasi-continuous electron energy loss to the lattice bath. A novel physical feature of the kinetics considered here is the slowing down of the electron–phonon relaxation in the vicinity of the Fermi energy of the degenerate subsystem, due to the fermionic blocking of the interaction phase space. This leads to a peaking of the calculated hot electron distribution at the Fermi energy. This feature, as well as the entire evolution of the hot electron distribution, may be time-resolved by a pump-probe study. The model is particularly applicable to disordered metallic systems with low electron concentrations and strong electron–phonon coupling, and that are at high temperatures, where the usual two-temperature model1–3 may not be appropriate. [ABSTRACT FROM AUTHOR]

• A review and a critique of the leading theoretical approaches in the field of Cuprate high temperature superconductivity are presented. • Requirements of an overarching and successful theory are listed. • Some key experimental facts are discussed. • Current theories are examined by comparing their predictions with the key experimental facts. We present a review of the leading theoretical approaches in the field of cuprate high temperature superconductivity. We start out by defining the problem and ask the question: whether an overarching theory possible (which is capable of explaining not only the mechanism of unconventional superconductivity but also a coherent understanding of the strange metal phase and the pseudogap phase)? If it is possible, what should we expect from the overarching theory? We list various experimental facts, and point out what can we learn from them and where do current theories stand in addressing them? Next, we present a critique of the current leading approaches. We conclude that although progress in the field has been unprecedented, but we still lack a coherent understanding. [ABSTRACT FROM AUTHOR]

Abstract: The Dunlap–Kenkre (DK) result states that dynamical localization of a driven quantum particle in a periodic lattice happens when the ratio of the field magnitude to the field frequency of the diagonal drive is a root of the ordinary Bessel function of order 0. This has been experimentally verified. A generalization of the DK result is presented here. The hitherto considered DK model contains only the diagonal forcing. In the present extended version of the DK model we consider both off-diagonal and diagonal driving fields with different frequencies and a definite relative phase between them. We analytically show that new dynamical localizations conditions exist where an important role is played by the relative phase. In appropriate limits our results reduce to DK result. [Copyright &y& Elsevier]

Recently, Hall effect measurements are done on Lanthanum doped Strontium Iridate S r 2 − x L a x I r O 4 which is 5d analogue of cuprates [1]. Hall effect measurements show that the effective carrier density n H exhibits a crossover from n H ∼ x to n H ∼ 1 + x near x ≃ 0.16. This is very similar to that found in cuprates around p ≃ 0.19. It is proposed that a pseudogap (PG) state in S r 2 − x L a x I r O 4 exists and is ending at x ≃ 0.16 [1]. However, PG boundary (in doping-temperature phase diagram) remains unknown. In this work, we apply a very successfull the Gor'kov-Teitel'baum Thermal Activation (GTTA) model to S r 2 − x L a x I r O 4 and obtain its PG phase boundary and draw an updated phase diagram. Our results agree with previously known signatures of PG phase in this system [2–4]. Using results from GTTA model we also obtain the evolution of "Fermi arcs" in this system as a function temperature for doping concentration x ≃ 0.08 which are in qualitative agreement with the reported results. • The Gor'kov-Teitel'baum Thermal Activation (GTTA) model is applied to Sr 2−x La x IrO 4 to obtain its Pseudogap phase boundary. • The results agree with previously reported Pseudogap signatures. • "Fermi arc" evolution with temperature is studied for x∼0.08 which is in qualitative agreement with reported results. • An updates phase diagram predicting the Pseudogap phase boundary for Sr 2−x La x IrO 4 is drawn. [ABSTRACT FROM AUTHOR]

Ketogenic Diet (KD) is a high-fat, adequate-protein, and low carbohydrate diet. With the intake of ketogenic diet, the body burn more fats in comparison to carbohydrates to get energy. KD is recommended in the treatment of several neurological diseases due to its role in neuroprotection. Its neuro protective role is exerted through the reduction of oxidative stress, maintenance of energy utilisation, modulation of inflammation, modulation of de-acetylation process, and other possible mechanisms. Although exact mechanisms for its beneficial effects in the treatment of neurological diseases is still uncertain, but it is well documented that oxidative damage, energy metabolism disorders or various inflammatory reactions affect the human health in neurological disorders. In neural disorder like convulsion, Alzheimer's disease, Parkinson disease etc, KD supports and facilitates in getting the positive outcome of therapy of the disease. It is helpful in improvisation of the symptoms and quality of life of affected patients. In this review article, role of ketogenic diet in various neurological disorders is focussed. [ABSTRACT FROM AUTHOR]

• In this manuscript we present our calculation of D.C. resistivity in a 2 d quantum critical metal and rigorously show that ρ p a r a 2 d ∝ T 4 3 near the critical point. • For the computation of resistivity we computed dynamical spin susceptibility of a 2 d quantum critical metal using Random Phase Approximation and we find that its real and imaginary parts scale as q 2 and ω q respectively. • Our RPA calculations agrees with the SCR theory calculations. It shows that re-normalized effects of soft modes just above the critical point do not affect the temperature dependence of resistivity. We calculate resistivity in the paramagnetic phase just above the curie temperature in a 2 d ferromagnetic metal. The required dynamical susceptibility in the formalism of resistivity is calculated within the Random Phase Approximation (RPA). The mechanism of resistivity is magnetic scattering, in which s -band electrons are scattered off the magnetic spin fluctuations of d-band electrons. We use the s - d Hamiltonian formalism. We find that near the quantum critical point the resistivity in 2 d scales as T 4 3 and in the high temperature limit resistivity scales as proportional to T. In contrast to it, resistivity due to phonon scattering is given by T 5 in low temperature limit as is well known. Our RPA result agrees with the Self-Consistence Renormalization (SCR) theory result. [ABSTRACT FROM AUTHOR]

We apply memory function formalism to investigate nonequilibrium electron relaxation in graphene. Within the premises of two-temperature model (TTM), explicit expressions of the imaginary part of the memory function or generalized Drude scattering rate (1/ τ) are obtained. In the DC limit and in equilibrium case where electron temperature (Te) is equal to phonon temperature (T), we reproduce the known results (i.e., 1/ τ ∝ T4 when T ≪ Θ BG and 1/ τ ∝ T when T ≫ Θ BG , where Θ BG is the Bloch–Grüneisen temperature). We report several new results for 1/ τ where T ≠ Te relevant in pump–probe spectroscopic experiments. In the finite-frequency regime we find that 1/ τ ∝ ω 2 when ω ≪ ω BG , and for ω = ω BG it is ω -independent. These results can be verified in a typical pump–probe experimental setting for graphene. [ABSTRACT FROM AUTHOR]

Differences in botanical diet compositions among a large number of moose faecal samples collected during winter correlated with the nutritional differences identified in the same samples (Mantel‐r = 0.89, p = 0.001), but the nutritional differences were significantly smaller (p < 0.001).Nutritional geometry revealed that moose mixed Scots pine Pinus sylvestris and Vaccinium spp. as nutritionally complementary foods to reach a nutritional target resembling Salix spp. twigs, and selected for Salix spp. browse (Jacob's D > 0).Available protein (AP) and total non‐structural carbohydrates (TNC) were significantly correlated in observed diets but not in hypothetical diets based on food availability.The level of Acetoacetate in moose serum (i.e. 'starvation') was weakly negatively associated with digestibility of diets (p = 0.08) and unrelated to increasing AP:TNC and AP:NDF ratios in diets (p > 0.1).Our study is the first to demonstrate complementary feeding in free‐ranging moose to attain a nutritional target that has previously been suggested in a feeding trial with captive moose. Our results add support to the hypothesis of nutritional balancing as a driver in the nutritional strategy of moose with implications for both the management of moose and food resources. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Spatiotemporal reindeer population fluctuations are a result of multiple factors that working in concert affecting the structure and functioning of many Arctic and Sub-Arctic ecosystems. We investigated the population dynamics of Swedish semi-domestic reindeer from 1945 to 2012 at the reindeer herding district-level (Sameby) to identify possible population collapses or declines. We also explored spatial trends and synchrony in population dynamics across latitudinal-longitude gradients for two distinct periods: 1945-1965 and 1995-2012 but found no evidence of large-scale reindeer population declines and no visible synchrony across adjacent populations. Our findings were unexpected as both reindeer populations and the pastoral lifestyle face increased habitat loss, predation, fragmentation and climate change. [ABSTRACT FROM AUTHOR]

Climate change represents a growing ecological challenge. The (sub) arctic and boreal regions of the world experience the most rapid warming, presenting an excellent model system for studying how climate change affects mammals. Moose (Alces alces) are a particularly relevant model species with their circumpolar range. Population declines across the southern edge of this range are linked to rising temperatures. Using a long-term dataset (1988–1997, 2017–2019), we examine the relative strength of direct (thermoregulatory costs) and indirect (food quality) pathways linking temperature, precipitation, and the quality of two important food items (birch and fireweed) to variation in moose calf mass in northern Sweden. The direct effects of temperature consistently showed stronger relationships to moose calf mass than did the indirect effects. The proportion of growing season days where the temperature exceeded a 20 °C threshold showed stronger direct negative relationships to moose calf mass than did mean temperature values. Finally, while annual forb (fireweed) quality was more strongly influenced by temperature and precipitation than were perennial (birch) leaves, this did not translate into a stronger relationship to moose calf weight. The only indirect path with supporting evidence suggested that mean growing season temperatures were positively associated with neutral detergent fiber, which was, in turn, negatively associated with calf mass. While indirect impacts of climate change deserve further investigation, it is important to recognize the large direct impacts of temperature on cold-adapted species. [ABSTRACT FROM AUTHOR]

Anthropogenic changes to land use drive concomitant changes in biodiversity, including that of the soil microbiota. However, it is not clear how increasing intensity of human disturbance is reflected in the soil microbial communities. To address this issue, we used amplicon sequencing to quantify the microbiota (bacteria and fungi) in the soil of forests (n = 312) experiencing four different land uses, national parks (set aside for nature conservation), managed (for forestry purposes), suburban (on the border of an urban area) and urban (fully within a town or city), which broadly represent a gradient of anthropogenic disturbance. Alpha diversity of bacteria and fungi increased with increasing levels of anthropogenic disturbance, and was thus highest in urban forest soils and lowest in the national parks. The forest soil microbial communities were structured according to the level of anthropogenic disturbance, with a clear urban signature evident in both bacteria and fungi. Despite notable differences in community composition, there was little change in the predicted functional traits of urban bacteria. By contrast, urban soils exhibited a marked loss of ectomycorrhizal fungi. Soil pH was positively correlated with the level of disturbance, and thus was the strongest predictor of variation in alpha and beta diversity of forest soil communities, indicating a role of soil alkalinity in structuring urban soil microbial communities. Hence, our study shows how the properties of urban forest soils promote an increase in microbial diversity and a change in forest soil microbiota composition. [ABSTRACT FROM AUTHOR]

Memory function formalism or projection operator technique is an extremely useful method to study the transport and optical properties of various condensed matter systems. A recent revival of its uses in various correlated electronic systems is being observed. It is being used and discussed in various contexts, ranging from nonequilibrium dynamics to the optical properties of various strongly correlated systems such as high temperature superconductors. However, a detailed discussion on this method, starting from its origin to its present day applications at one place is lacking. In this paper, we attempt a comprehensive review of the memory function approach focusing on its uses in studying the dynamics and the transport properties of correlated electronic systems. [ABSTRACT FROM AUTHOR]

The memory function formalism is an important tool to evaluate the frequency dependent electronic conductivity. It is previously used within some approximations in the case of electrons interacting with various other degrees of freedom in metals with great success. However, one needs to go beyond those approximations as the interaction strengths become stronger. In this work, we propose a systematic expansion of the memory function involving its various moments. We calculate the higher order contribution to the generalized Drude scattering rate in case of electron–impurity interactions. Further we compare our results with the results from previously studied lowest order calculations. We find larger contributions from the higher moments in the low frequency regime and also in the case of larger interaction strength. [ABSTRACT FROM AUTHOR]

Food acquisition and security from predators are primary determinants of habitat use in ungulates. There is usually a trade-off in the response of animals to these two factors, influenced by the individual's reproductive state. Females with vulnerable offspring, after parturition, are expected to compromise food acquisition for security. In temperate species such as the markhor Capra falconeri, however, the females give birth at a time when nutritious forage begins to become available after the long lean period of winter. The need to access quality forage in spring should, therefore, be significant even for new mothers, making the issue of female habitat choice particularly interesting and important to understand. We assessed habitat use patterns of the Pirpanjal markhor during the winter and parturition periods, to examine the response of markhor females to contrasting pressures of forage acquisition and neonate security. Markhor were observed during morning and evening hours along trails and vantage points in the Limber Wildlife Sanctuary, western Himalaya, India. Vegetation abundance and quality were assessed. Principal Components Analyses revealed that during winter, as expected, access to forage was the primary factor influencing habitat choice by female markhor. Following parturition, however, despite the low availability of quality forage throughout the preceding winter, markhor mothers predominantly used secure areas with steep slopes closer to cliffs, even though they were poorer in forage availability. Our results underscore the importance of neonate security in determining habitat use of markhor and the causes of low productivity of this population. [ABSTRACT FROM AUTHOR]