Restricted Dynamic Programming Heuristic for Precedence Constrained Bottleneck Generalized TSP

We develop a restricted dynamical programming heuristic for a complicated traveling salesman problem: a) cities are grouped into clusters, resp. Generalized TSP; b) precedence constraints are imposed on the order of visiting the clusters, resp. Precedence Constrained TSP; c) the costs of moving to the next cluster and doing the required job inside one are aggregated in a minimax manner, resp. Bottleneck TSP; d) all the costs may depend on the sequence of previously visited clusters, resp. Sequence-Dependent TSP or Time Dependent TSP. Such multiplicity of constraints complicates the use of mixed integer-linear programming, while dynamic programming (DP) benefits from them; the latter may be supplemented with a branch-and-bound strategy, which necessitates a “DP-compliant” heuristic. The proposed heuristic always yields a feasible solution, which is not always the case with heuristics, and its precision may be tuned until it becomes the exact DP

Substrate recognition determinants of benzylsuccinate synthase and other fumarate-adding glycyl radical enzymes

The pathway of anaerobic toluene degradation is initiated by a radical-type fumarate addition, catalyzed by the remarkable glycyl radical enzyme benzylsuccinate synthase (BSS). It has been found that benzylsuccinate synthase is a member of fumarate-adding enzymes (FAEs), which are involved in the anaerobic biodegradation pathways of various hydrocarbons, both aromatic and aliphatic. 2-naphthyl(methylsuccinate) synthase (NMS) is a member of the FAE family, which is predicted to catalyze a similar radical type addition reaction, using 2-methylnaphthalene as substrate. In this study we have shown structure-functional characterization of recombinant BSS from Thauera aromatica K172 and NMS from the 2-methylnaphthalene degrading enrichment culture N47. We have established the first recombinant overproduction system of active benzylsuccinate synthase and present initial data on the effects of some constructed active-site mutants in the alpha subunit of the enzyme. We demonstrate that a single isoleucine substitution to valine inside the hydrophobic pocket of the active site of BSS leads to an extended substrate range of the mutated variant including conversion of m-xylene. Moreover, we show that a mutation of a highly conserved arginine to lysine or glutamine significantly decreases or eliminates the activity of BSS, proving the importance of this arginine in fumarate binding during catalysis. Remarkably, we demonstrate that an arginine to lysine substitution enables the conversion of a fumarate analogue – 3-acetyl acrylate, which is not converted by the wild type BSS. Overall, this study provides new insight on the reaction mechanism and catalytic parameters of BSS and elucidates the roles of certain amino acids in substrate recognition and binding. Subsequently, we have implemented our overproduction system and produced active NMS, which displayed low reactivity with toluene. This data serve as an initial proof of the fumarate addition nature of NMS - previously a putative candidate to perform this chemical reaction. Moreover, we have overproduced and purified non-activated forms of BSS and NMS in E. coli in order to further characterize the protein complexes by X-Ray crystallography and EPR-spectroscopy

Low missing mass, single- and double diffraction dissociation at the LHC

Low missing mass, single- and double diffraction dissociation is calculated for the LHC energies from a dual-Regge model, dominated by a Pomeron Regge pole exchange. The model reproduces the rich resonance structure in the low missing mass Mx region. The diffractionly excited states lie on the nucleon trajectory, appended by the isolated Roper resonance. Detailed predictions for the squared momentum transfer and missing mass dependence of the differential and integrated single- and double diffraction dissociation in the kinematical range of present and future LHC measurements are given. The model predicts a possible turn-down of the cross section towards, t -> 0 in a region probably accessible in future experiments in the nearly forward direction. The present work is a continuation and extension (e.g. with double diffraction) of a previous work using the dual Regge approach

The Spatial-Kinematic Structure of the Region of Massive Star Formation S255N on Various Scales

The results of a detailed analysis of SMA, VLA, and IRAM observations of the region of massive star formation S255N in CO(2---1), \nh, \nhh, \co and some other lines is presented. Combining interferometer and single-dish data has enabled a more detailed investigation of the gas kinematics in the moleclar core on various spatial scales. There are no signs of rotation or isotropic compression on the scale of the region as whole. The largest fragments of gas ($\approx$0.3 pc) are located near the boundary of the regions of ionized hydrogen S255 and S257. Some smaller-scale fragments are associated with protostellar clumps. The kinetic temperatures of these fragments lie in the range 10---80 K. A circumstellar torus with inner radius R$_{in}$ $\approx$ 8000 AU and outer radius R$_{out}$ 12 000 AU has been detected around the clump SMA1. The rotation profile indicates the existence of a central object with mass $\approx$ 8.5/ sin 2 (i) M$_\odot$ . SMA1 is resolved into two clumps, SMA1---NE and SMA1---SE, whose temperatures are $\approx$150 K and $\approx$25 K, respectively. To all appearances, the torus is involved in the accretion of surrounding gas onto the two protostellar clumps

ХРОНІЧНА ПОСТТРАВМАТИЧНА ЕНЦЕФАЛОПАТІЯ. ПОГЛЯД НА ПРОБЛЕМУ

Summary. Chronic traumatic encephalopathy (CTE) is a unique neurodegenerative tauopathy first described in boxers but more recently described in a variety of contact sport athletes, military veterans, and civilians exposed to repetitive mild traumatic brain injury. The aim of the study – to analyze the world experience of the last decade in the study of prevalence, risk factors, pathogenesis and diagnosis of chronic traumatic encephalopathy. Materials and Methods. Available resources in the Internet, foreign professional publications, MEDLINE/PubMed medical databases of the last ten years were analyzed. The method of information search and analytical-comparative method were applied. Results. Experimental and clinical works of the last decade were aimed at solving numerous problems such as defining the prevalence of СTE, risk factors, basic pathogenetic mechanisms, improving morphological and clinical criteria, attempts to classify СTE, search for biomarkers and specific neurovisual criteria. Clinically, there are characteristic progressive deficits in cognition (me­mory, executive dysfunction), behavior (explosivity, aggression), mood (depression, suicidality), and motor function (dys­arthria, dysgraphia, bradykinesia, tremor, rigidity, gait disturbance, falls, and/or other features of parkinsonism). The search for consensus on the clinical classification of СTE continues. Morphologically, СTE is characterized by a focal perivascular deposits of p-tau in the neocortex, microgliosis and astrocytosis, which leads to progressive neurodegeneration. The frontal, temporal and parietal lobes are often affected. The role of contact sports, the age the first traumatic brain injury was received (critically 9–12 years), the duration of a sports career has been determined. Conclusions. Despite the almost century-long history of studying СTE the number of issues to be addressed is growing. It is promising to search for diagnostic criteria that will not only confirm the diagnosis of CTE in life, but also to determine markers (neuronal, axonal and astroglial trauma) that will predict the risk of neurodegenerative pathology after traumatic brain injury.Резюме. Хронічна травматична енцефалопатія (ХТЕ) – унікальна нейродегенеративна таупатія – вперше описали в боксерів, а згодом, у спортсменів контактних видів спорту, військових ветеранів та цивільних, які піддавалися повторним легким черепно-мозковим травмам. Мета дослідження – проаналізувати світовий досвід останнього десятиліття у дослідженні поширеності, факторів ризику, патогенезу та діагностики хронічної травматичної енцефалопатії. Матеріали і методи. Здійснено аналіз доступних інформаційних ресурсів мережі «Internet», іноземних фахових видань, медичної бази даних MEDLINE/PubMed за останні десять років. Застосовано метод інформаційного пошуку та аналітико-порівняльний. Результати. Експериментальні та клінічні роботи останнього десятиліття спрямовані на вирішення численних проблем, зокрема встановлення поширеності ХТЕ, факторів ризику, основних патогенетичних механізмів, удосконаленні морфологічних та клінічних критеріїв, спробах класифікувати ХТЕ, пошуку біомаркерів та специфічних нейровізуальних критеріїв. Клінічно для патології властиві прогресуючі когнітивні (пам’ять, виконавча дисфункція, візуально-просторова дисфункція) й поведінкові (збудливість, агресія) розлади, зміни настрою (депресія, суїцидальність) та рухові порушення (дисфагія, брадикінезія, тремор, ригідність, порушення ходи, падіння тощо). Триває пошук консенсусу щодо клінічної класифікації ХТЕ. Морфологічно ХТЕ характеризується процесами накопичення фосфорильованого тау (р-тау) у верхівках і навколосудинних ділянках, мікрогліозу та астроцитозу, що призводить до прогресуючої нейродегенерації. Ураження зазнають в основному лобна, скронева та потилична частки. Встановлено роль контактних видів спорту, віку, в якому було отримано першу черепно-мозкову травму (критично 9–12 років), тривалості спортивної кар’єри. Висновки. Незважаючи на майже столітню історію вивчення ХТЕ, з часом кількість питань, які потребують вирішення, – зростає. Перспективним є пошук діагностичних критеріїв, які дозволять не лише прижиттєво підтвердити діагноз ХТЕ, але і встановити маркери (нейрональної, аксональної та астрогліальної травм), що прогнозуватимуть ризик розвитку нейродегенеративної патології після черепно-мозкової травми

Molecular gas in high-mass filament WB673

We studied the distribution of dense gas in a filamentary molecular cloud containing several dense clumps. The center of the filament is given by the dense clump WB673. The clumps are high-mass and intermediate-mass star-forming regions. We observed CS(2-1), 13CO(1-0), C18O(1-0) and methanol lines at 96GHz toward WB673 with the Onsala Space Observatory 20-m telescope. We found CS(2-1) emission in the inter-clump medium so the clumps are physically connected and the whole cloud is indeed a filament. Its total mass is $10^4$ M$_{\odot}$ and mass-to-length ratio is 360 M$_{\odot}$pc$^{-1}$ from 13CO(1-0) data. Mass-to-length ratio for the dense gas is $3.4-34$ M$_{\odot}$pc$^{-1}$ from CS(2-1) data. The PV-diagram of the filament is V-shaped. We estimated physical conditions in the molecular gas using methanol lines. Location of the filament on the sky between extended shells suggests that it could be a good example to test theoretical models of formation of the filaments via multiple compression of interstellar gas by supersonic waves

Durasi Penggunaan Media Sosial Dan Insomnia Pada Remaja

Rest and sleep are physiological needs that must be met by every teenager. The inability of teenagers in managing time to use social media will have an impact on irregular sleep patterns so that the occurrence of insomnia. This study aims to determine the relationship of the duration of social media use with insomnia in teenager at Advent Klabat Manado High School. The method used in this study is an analytic survey with cross sectional approach. Data of 155 respondents were collected using a questionnaire through a total sampling technique. Data were analyzed bivariately using the spearman correlation test. The results of this study descriptively that there were 91 respondents (58.7%) dominant with a moderate duration of social media use (3-4 hours a day) and 99 respondents (56.8%) had moderate insomnia. There is a strong and positive correlation between the duration of social media use and the incidence of insomnia in adolescents at Manado Klabat Advent High School (p value = 0.00 <0.05, with r = 0.739). It is expected that teenagers to reduce the use of social media and replace with other useful activities, for researchers can then analyze specifically the types of social media that are often used by teenagers. Keywords: duration, use of social media, insomnia, teenager