Modeling the mobility of living organisms in heterogeneous landscapes: Does memory improve foraging success?

Thanks to recent technological advances, it is now possible to track with an unprecedented precision and for long periods of time the movement patterns of many living organisms in their habitat. The increasing amount of data available on single trajectories offers the possibility of understanding how animals move and of testing basic movement models. Random walks have long represented the main description for micro-organisms and have also been useful to understand the foraging behaviour of large animals. Nevertheless, most vertebrates, in particular humans and other primates, rely on sophisticated cognitive tools such as spatial maps, episodic memory and travel cost discounting. These properties call for other modeling approaches of mobility patterns. We propose a foraging framework where a learning mobile agent uses a combination of memory-based and random steps. We investigate how advantageous it is to use memory for exploiting resources in heterogeneous and changing environments. An adequate balance of determinism and random exploration is found to maximize the foraging efficiency and to generate trajectories with an intricate spatio-temporal order. Based on this approach, we propose some tools for analysing the non-random nature of mobility patterns in general.Comment: 14 pages, 4 figures, improved discussio

Nonlinear Reaction–Diffusion Process Models Improve Inference for Population Dynamics

Partial differential equations (PDEs) are a useful tool for modeling spatiotemporal dynamics of ecological processes. However, as an ecological process evolves, we need statistical models that can adapt to changing dynamics as new data are collected. We developed a model that combines an ecological diffusion equation and logistic growth to characterize colonization processes of a population that establishes long‐term equilibrium over a heterogeneous environment. We also developed a homogenization strategy to statistically upscale the PDE for faster computation and adopted a hierarchical framework to accommodate multiple data sources collected at different spatial scales. We highlighted the advantages of using a logistic reaction component instead of a Malthusian component when population growth demonstrates asymptotic behavior. As a case study, we demonstrated that our model improves spatiotemporal abundance forecasts of sea otters in Glacier Bay, Alaska. Furthermore, we predicted spatially varying local equilibrium abundances as a result of environmentally driven diffusion and density‐regulated growth. Integrating equilibrium abundances over the study area in our application enabled us to infer the overall carrying capacity of sea otters in Glacier Bay, Alaska

A next-generation inverse-geometry spallation-driven ultracold neutron source

The physics model of a next-generation spallation-driven high-current ultracold neutron (UCN) source capable of delivering an extracted UCN rate of around an-order-of-magnitude higher than the strongest proposed sources, and around three-orders-of-magnitude higher than existing sources, is presented. This UCN-current-optimized source would dramatically improve cutting-edge UCN measurements that are currently statistically limited. A novel "Inverse Geometry" design is used with 40 L of superfluid $^4$He (He-II), which acts as a converter of cold neutrons (CNs) to UCNs, cooled with state-of-the-art sub-cooled cryogenic technology to $\sim$1.6 K. Our design is optimized for a 100 W maximum heat load constraint on the He-II and its vessel. In our geometry, the spallation target is wrapped symmetrically around the UCN converter to permit raster scanning the proton beam over a relatively large volume of tungsten spallation target to reduce the demand on the cooling requirements, which makes it reasonable to assume that water edge-cooling only is sufficient. Our design is refined in several steps to reach $P_{UCN}=2.1\times10^9\,/$s under our other restriction of 1 MW maximum available proton beam power. We then study effects of the He-II scattering kernel as well as reductions in $P_{UCN}$ due to pressurization to reach $P_{UCN}=1.8\times10^9\,/$s. Finally, we provide a design for the UCN extraction system that takes into account the required He-II heat transport properties and implementation of a He-II containment foil that allows UCN transmission. We estimate a total useful UCN current from our source of $R_{use}=5\times10^8\,/$s from a 18 cm diameter guide 5 m from the source. Under a conservative "no return" approximation, this rate can produce an extracted density of $>1\times10^4\,/$cm$^3$ in $<$1000~L external experimental volumes with a $^{58}$Ni (335 neV) cut-off potential.Comment: Submitted to Journal of Applied Physic

Мировой опыт срочной медицинской службы

In this article the author examines the system of organization of emergency medical care for life-threatening conditions and diseases at the scene and en route to medical facilities. The concept of medical emergency is defined and a brief history of the development of this phenomenon is provided. The author examines six aspects of the ambulance, according to the “Star of Life”. Other aspects under consideration - the training of paramedics, types of urgent actions carried out directly at the scene, the types of paramedics according to the level of medical training and the dominant international types of organization of paramedical services.В данной статье автор рассматривает систему организации экстренной медицинской помощи при угрожающих жизни состояниях и заболеваниях на месте происшествия и в пути следования в лечебно-профилактические учреждения. Определяется понятие и приводится краткая история развития «скорой медицинской помощи». Согласно «Звезде Жизни», автор анализирует 6 аспектов системы скорой медицинской помощи. Другие рассматриваемые аспекты – это подготовка персонала станций скорой медицинской помощи, виды неотложных мероприятий, проводимых непосредственно на месте происшествия, категории парамедиков по уровню медицинской подготовки и доминирующие международные виды организации службы парамедиков

Modern anatomo–clinical argumentation of the a acupuncture as a method for analgesia

Catedra de anatomie topografică şi chirurgie operatorie, Universitatea de Stat de Medicină și Farmacie ”Nicolae Testemițanu”, Chișinău, Republica Moldova, Conferința Ştiinţifică Internaţională ”Probleme actuale ale morfologiei” dedicată celor 70 de ani de la fondarea Universității de Stat de Medicină și Farmacie „Nicolae Testemiţanu”, Chişinău, 15-16 octombrie 2015Abstract Background: Acupuncture is a therapeutic method that comes from China and is based on the meridian’s theory. Many analgesic drugs used for postoperative pain have a number of side effects. Acupuncture claims to develop a maximum therapeutic effect with reduced side effects. Material and methods: Individualized set of acupuncture needles; visual analogical-scale; tonometer; thermometer; questionnaire for evaluation of postoperative pain management; questionnaire for assessing the patient satisfaction about acute postoperative pain management; informed consent of the patient included in the study. The study included 14 patients who underwent a microsurgical intervention on the hand (amputation of two fingers). They were divided into two. Patients of the first group received 3 sessions of acupuncture and Baralgin. Those in the second group followed only promedol. Patients were evaluated according to objective and subjective criteria: visual-analogical scale (VAS), personal convenience, blood pressure, temperature, respiratory rate, heart rate. 136 Results: Patients who received acupuncture showed normalization of objective and subjective indicators and the absence of any adverse effects. Conclusions: 1. Acupuncture is a method of therapy based on stimulation of acupoints that frequently correspond to nerve formations; 2. The analgesic effect of acupuncture allow the exclusion of opioid analgesics and use of minor analgesics for postoperative pain management; 3. Acupuncture in combination with minor analgesics provides postoperative pain soothing and early improving of objective indicators

Гирудотерапия – путь к экологичной медицине

The modern medicine in its actual form has existed only about 100 years. It has reached very significant results in the treatment of health states, requiring urgent medical asisstance, with the help of synthetic drugs. In a relatively short period of time an impressive pharmaceutical industry that sells immense amounts of drugs has been created. At the same time when the synthetic drugs are used in the treatment of chronic diseases, besides the positive results, a lot of undesirable effects can be observed. The last generations have been “massively attacked” with a big variety of such drugs. These methods of treatment have caused an “ecological disaster” in the human organism and leaded to the different types of allergy and toxic reactions. According to the medical literature about 50% of diseases are iatrogenic. So, in the modern medicine has appeared such a concept as a “drug – induced disease”. Taking into consideration the high percentage of such pathological processes, the scientists and physicians have started to study more intensively the folk medicine which has by far less side effects. Hirudotherapy is a part of it. A medical leech has many positive effects on the human body without “contaminating” it with different synthetic substances. This method is recommended for the treatment of many systemic diseases. Hirudotherapy is practiced in many European and CIS countries. In 1990 the International Association of Hirudotherapists was created, and in 1991 the First International Congress was held. The latest scientific researches prove that the modern and folk medicine are very well combined with each other. In conclusion we can say with confidence that the treatment with leeches has its special role. This ancient method of therapy has an enormous potential both from practical (it can be used in applied medicine) and scientific point of view. So, hirudotherapy must take its deserved place in the modern medicine in the Republic of Moldova as well.Современная медицина в своём нынешнем виде существует не более 100 лет. Она достигла значительных результатов в лечении состояний, требующих неотложной медицинской помощи, посредством синтетических медикаментов. За относительно короткий период была создана внушительная фармацевтическая индустрия, поставляющая огромное количество лекарств. В то же время при хронических заболеваниях, для лечения которых применяются синтетические препараты, наравне с позитивными результатами, наблюдается и много нежелательных эффектов. Последние поколения были «массивно обстреляны» различными препаратами такого типа. Эти методы лечения вызвали «экологическую катастрофу» на уровне организма, что привело к появлению разных типов аллергии и токсических реакций. По данным литературы около 50% заболеваний являются ятрогенными, в связи с этим в медицине появилось такое понятие как «медикаментозная болезнь». Принимая во вниманиe большой масштаб этих патологических процессов, учёные и врачи направили свои усилия в сторону народной медицины, где наблюдается гораздо меньшее количество побочных реакций. К категории последней и относится гирудотерапия. Лечебная пиявка оказываeт ряд положительных воздействий на организм человека, не «загрязняя» его различными синтетическими веществами. Этот метод лечения показан при многих системных заболеваниях. Гирудотерапия практикуется во многих европейских странах и СНГ. В 1990г. была создана Международная Ассоциация Гирудологов, а в 1991г. прошёл Первый Международный Конгресс. Последние научные исследования доказывают, что традиционная и народная медицина очень хорошо взаимно дополняются. В заключении можно с уверенностью сказать, что лечение пиявками имеет особое значение. Этот древнейший метод терапии обладает огромным потенциалом, как с практической, так и с научной точки зрения. Гирудотерапия должна занять своё достойное место в современной медицине и в Республике Молдова

Spontaneous symmetry breaking in amnestically induced persistence

We investigate a recently proposed non-Markovian random walk model characterized by loss of memories of the recent past and amnestically induced persistence. We report numerical and analytical results showing the complete phase diagram, consisting of 4 phases, for this system: (i) classical nonpersistence, (ii) classical persistence (iii) log-periodic nonpersistence and (iv) log-periodic persistence driven by negative feedback. The first two phases possess continuous scale invariance symmetry, however log-periodicity breaks this symmetry. Instead, log-periodic motion satisfies discrete scale invariance symmetry, with complex rather than real fractal dimensions. We find for log-periodic persistence evidence not only of statistical but also of geometric self-similarity.Comment: 4 pages, 2 color fig

Agricultural productivity in past societies: toward an empirically informed model for testing cultural evolutionary hypotheses

Agricultural productivity, and its variation in space and time, plays a fundamental role in many theories of human social evolution. However, we often lack systematic information about the productivity of past agricultural systems on a scale large enough to test these theories properly. The effect of climate on crop yields has received a great deal of attention resulting in a range of empirical and process-based models, yet the focus has primarily been on current or future conditions. In this paper, we argue for a “bottom-up” approach that estimates potential productivity based on information about the agricultural practices and technologies used in past societies. Of key theoretical interest is using this information to estimate the carrying high quality historical and archaeological information about past societies in order to infer the temporal and geographic patterns of change in agricultural productivity and potential. We discuss information we need to collect about past agricultural techniques and practices, and introduce a new databank initiative that we have developed for collating the best available historical and archaeological evidence. A key benefit of our approach lies in making explicit the steps in the estimation of past productivities and carrying capacities, and in being able to assess the effects of different modelling assumptions. This is undoubtedly an ambitious task, yet promises to provide important insights into fundamental aspects of past societies, enabling us to test more rigorously key hypotheses about human socio-cultural evolution

Amnestically induced persistence in random walks

We study how the Hurst exponent $\alpha$ depends on the fraction $f$ of the total time $t$ remembered by non-Markovian random walkers that recall only the distant past. We find that otherwise nonpersistent random walkers switch to persistent behavior when inflicted with significant memory loss. Such memory losses induce the probability density function of the walker's position to undergo a transition from Gaussian to non-Gaussian. We interpret these findings of persistence in terms of a breakdown of self-regulation mechanisms and discuss their possible relevance to some of the burdensome behavioral and psychological symptoms of Alzheimer's disease and other dementias.Comment: 4 pages, 3 figs, subm. to Phys. Rev. Let

In-situ measurement and the reconstruction in 3D of femtosecond inscription induced complex permittivity modification in glass

We demonstrate a new approach to in-situ measurement of femtosecond laser pulse induced changes in glass enabling the reconstruction in 3D of the induced complex permittivity modification. The technique can be used to provide single shot and time resolved quantitative measurements with a micron scale spatial resolution