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

Detection of quantum light in the presence of noise

Detection of quantum light in the presence of dark counts and background radiation noise is considered. The corresponding positive operator-valued measure is obtained and photocounts statistics of quantum light in the presence of noise is studied.Comment: 4 pages, 1 figure; misprints correcte

Introducing Christianity into Christendom: investigating the affinity between Søren Kierkegaard and the early thought of Karl Barth

The Swiss theologian Karl Barth’s (1886-1968) relation to the Danish thinker Søren Kierkegaard (1813-1855) is one which has been touched upon repeatedly with regard to influence and parallels. It is an issue that has produced diverse conclusions ranging from that of T. F. Torrance, who believed Barth to have been influenced by Kierkegaard to an extent even unknown to himself, to the likes of Bruce McCormack who views the affinity as exaggerated. However, this intriguing relationship refuses a conclusive position regarding the extent to which Barth had been influenced by Kierkegaard; any attempt that seeks to resolve this question disregards both the complexity of Barth’s thought and the sheer range of thinkers who had contributed to his theological development. Moreover, Barth’s own comments on the influence of Kierkegaard on his development complicate the investigation into the relationship between the two. Whereas in 1922 Barth admits a dependence on Kierkegaard in the second edition of The Epistle to the Romans, by 1963 he has assumed a more cautious relation to Kierkegaard

Use of ultrasound densitometry for the assess of structural and functional disorders of bone tissue and prediction of fractures risk

To determine the dependence of lumbar spine compression degree on BMD state and the patients’ age. The relationship of BMD state, the patients’ age and the degree of compression of the vertebrae were studied. Correlation and regression analysis of the relationship between SOS index, score of compression and patients' age have been examined. Results. The data obtained allowed us to develop a mathematical model for predicting BMD reduction and the severity of vertebral compression fractures. Conclusions. Ultrasonic indexes of bone mineral density may be used not only for its screening assessment in general population of different ages, but also in assessing the degree of structural and functional changes of BT, predicting the severity of low-energy osteoporosis fractures. It will help to assign treatment in preclinical stage, and carry out prevention of compression fractures

Deconvolution problems in x-ray absorption fine structure

A Bayesian method application to the deconvolution of EXAFS spectra is considered. It is shown that for purposes of EXAFS spectroscopy, from the infinitely large number of Bayesian solutions it is possible to determine an optimal range of solutions, any one from which is appropriate. Since this removes the requirement for the uniqueness of solution, it becomes possible to exclude the instrumental broadening and the lifetime broadening from EXAFS spectra. In addition, we propose several approaches to the determination of optimal Bayesian regularization parameter. The Bayesian deconvolution is compared with the deconvolution which uses the Fourier transform and optimal Wiener filtering. It is shown that XPS spectra could be in principle used for extraction of a one-electron absorptance. The amplitude correction factors obtained after deconvolution are considered and discussed.Comment: 6 two-column pages, 5 eps figures; submitted to J. Phys.: Appl. Phy

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

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

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

Biomechanical characteristics of different fixing methods of fractures of the talus

Досліджено характеристики жорсткості та надійність фіксації переломів стандартними та зустрічно-компресуючими гвинтами, що фіксують переломи тіла та шийки таранної кістки у реальних, включаючи циклічні, режимах дії зовнішніх навантажень. При передачі стискаючого зусилля на відламок тип фіксуючих гвинтів суттєво впливає на деформації системи остеосинтезу при всіх рівнях навантаження; залишкові деформації (взаємний зсув відламків) систем з зустрічно-компресуючими гвинтами суттєво менше залишкових деформацій систем з стандартними гвинтами. Застосування нових типів гвинтів суттєво підвищує стабільність фіксації та в цілому збільшує механічну надійність фіксації переломів таранної кістки.Purpose. Subject matter of the present paper is to investigate the characteristics of hardness and fixation of fractures with standard and self-tightening screws, fixing the oblique talus fracture in real regimes of external load including the cyclic ones. Design/methodology/approach. During the experiment the specimen of limbs without pathology of the bone tissue had been used. Fixation of the bone fragments (osteosynthesis) had been performed by the means of standard and self-tightening screws. Tests were conducted by transferring the load on fixed distal fragment fracture of the talus in the craneal direction. Downloads modes: one static and impact more cyclically variable loads that simulate human weight. Findings. During the transmission of the compressing force onto the fragment, the type of the fixing screw greatly influences the deformation of the osteosynthetic systems at all levels of load; permanent residual deformations (mutual shift of fragments) of the systems with self-tightening screws are much more lower if compared to the ones of the systems, employing the standard ones. Employment of the new type of screws significantly increases the fixation stability and generally increases the mechanical durability of the fixation of the oblique fracture of the talus fracture. Originality/value. Results are important for medicine and can improve treatment.В статье исследованы характеристики жесткости и надежность фиксации переломов стандартными и самокомпрессирующимися винтами, которые фиксируют перелом тела и шейки таранной кости в реальных, включая циклические, режимах действия внешних загрузок. При передачи сжимающего усилия на отломок тип фиксирующих винтов существенно влияет на деформации системы остеосинтеза при всех уровнях нагрузок; остаточные деформации (взаимный сдвиг отломков) систем с самокомпрессирующими винтами существенно меньше остаточных деформаций систем со стандартными винтами. Использование новых типов винтов существенно повышает стабильность фиксации и в целом увеличивает механическую надежность фиксации переломов таранной кости

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