Random Forest Spatial Interpolation

For many decades, kriging and deterministic interpolation techniques, such as inverse distance weighting and nearest neighbour interpolation, have been the most popular spatial interpolation techniques. Kriging with external drift and regression kriging have become basic techniques that benefit both from spatial autocorrelation and covariate information. More recently, machine learning techniques, such as random forest and gradient boosting, have become increasingly popular and are now often used for spatial interpolation. Some attempts have been made to explicitly take the spatial component into account in machine learning, but so far, none of these approaches have taken the natural route of incorporating the nearest observations and their distances to the prediction location as covariates. In this research, we explored the value of including observations at the nearest locations and their distances from the prediction location by introducing Random Forest Spatial Interpolation (RFSI). We compared RFSI with deterministic interpolation methods, ordinary kriging, regression kriging, Random Forest and Random Forest for spatial prediction (RFsp) in three case studies. The first case study made use of synthetic data, i.e., simulations from normally distributed stationary random fields with a known semivariogram, for which ordinary kriging is known to be optimal. The second and third case studies evaluated the performance of the various interpolation methods using daily precipitation data for the 2016–2018 period in Catalonia, Spain, and mean daily temperature for the year 2008 in Croatia. Results of the synthetic case study showed that RFSI outperformed most simple deterministic interpolation techniques and had similar performance as inverse distance weighting and RFsp. As expected, kriging was the most accurate technique in the synthetic case study. In the precipitation and temperature case studies, RFSI mostly outperformed regression kriging, inverse distance weighting, random forest, and RFsp. Moreover, RFSI was substantially faster than RFsp, particularly when the training dataset was large and high-resolution prediction maps were made

The influence of chronic exposition to lead on blood pressure

Pri obilasku jedne tvornice akumulatora uočili smo, da su radnici u toj tvornici izloženi mogućnostima jače apsorpcije olova. Sistematske mjerenje koncentracije olova u zraku svih pogona izvršeno je već prije, i tom je prilikom ustanovljeno, da se koncentracija olova u zraku te tvornice kreće od 0-2 mg/m3, a najčešće se koncentracija kretala od 0,2-0,4 mg/ma (5). Uvjeti rada u takvoj atmosferi dali su nam opravdan povod, da vjerujemo, da se radnici s duljim radnim stažom u ovoj tvornici nalaze u uvjetima kronične ekspozicije olovu. Predmet našeg ispitivanja bio je utjecaj kronične ekspozicije olovu na krvni pritisak. Na osnovu pregleda količine izlučenog koproporfirina u urinu, broja bazofilno punktiranih eritrocita u perifernoj krvi i količine olova u krvi izdvojili smo grupu od 46 radnika s najizrazitijim znacima apsorpcije olova i najdužim radnim stažom. Kontrolna grupa se sastojala od 46 radnika jedne tvornice metalne industrije, istih godina starosti, koji u svom proizvodnom procesu ne rade s olovom. Obje su grupe svrstane prema dobi života u 3 skupine, kako to pokazuju tablice I. i II. Kao elementi dokaza za pojačanu apsorpciju olova i kroničnu ekspoziciju uzeti su: koproporfirin u urinu, BpE u perifernoj krvi i količina olova u krvi. Kod kontrolne grupe vršena su ista ispitivanja izuzevši olovo u krvi, jer su vrijednosti koproporfirina u urinu, BpE u perifernoj krvi, kao i sam radni proces pokazivali, da ekspozicija olovu ne postoji.The purpose of this investigation was to find out whether chronic exposition to lead increases the blood pressure. A group of 46 workers in a storage battery factory has been examined. The concentration of lead in air has been previously estimated (Arh. hig. rada, 2 /1951/ 19) to vary from 0-2 mg/m3, most frequently from 0.2--0.4 mg/m3. ln the present investigation the exposition to lead has been measured by the concentration of lead in blood, the coproporphyrine level in urine and the number of stippled cells. The control group consisted of 46 metal workers with no known previous exposition to lead. The same examination have been performed on this group of workers except the determination of lead in blood. Both groups were examined under the same conditions; the experimental and the control group were balanced with respect to age. The measurements of the systolic blood pressure gave an arithmetic mean of 106 mm Hg in the experimental group (exposed to lead) and 116 in the control group. Thus the hypothesis that the chronic exposition to lead increases the blood pressure cannot be accepted on the basis of this evidence

Occupational radiodermatitis in workers handling radium

Iznose se pojave profesionalnog radiodermita kod 3 osobe, koje su bile zaposlene na Radiološkom institutu kao manipulanti radiumom. Kod dva slučaja postojala je klinička slika ulceroznog radiodermita, dok je kod trećeg postojala maligna alteracija tog oblika radium oštećenja u smislu Epithelioma spinocellulare udružena s radionekrozom krajnje falange palca desne ruke.The occurrence of occupational radiodermatitis in 3 persons handling radium at the Radiological Institute is described. Clinical picture of two cases showed ulcerous radiodermatitis, while in one case there was a malign alteration similar to Epithelioma spinocellulare and combined with the radionecrosis of the distal thumb phalanx of the right hand

Promene morfometrijskih parametara mastocita u srcu pacova akutno trovanih T-2 toksinom

Wistar rats were treated with T-2 toxin (1 LD50; 0.23 mg/kg sc) and the surviving animals were sacrificed on days 1, 3, 5, 7, 14, 21 and 28 after treatment. At each time, control animals were sacrificed, too. Cardiac mast cells, previously stained by Giemsa method, were analyzed in whole visual fields, magnification x40. In the present study the following quantitative morphometric parameters of cardiac mast cells were evaluated: perimeter (P), area (A) and roundness (R). In the control groups of rats the majority of mast cells were small (P = 6.86 - 7.99 mm), hypogranular (A = 11.60 -14.30 mm2) and ovoid (R = 0.60 - 0.65 mm). Mast cells, with discrete granules, hypergranular, had significantly different quantitative parameters (P = 12.80 -14.90 mm; A = 16.70 -20.00 mm2; R = 0.35 -0.38 mm). The minority of mast cells, classified as degranulated, had a large (P=20.70-23.30 mm), irregular shape (A = 24.40 -30.90 mm2) and showed degranulation (R = 0.15 - 0.21 mm). In the heart of T-2 toxin-treated rats the quantitative parametar values of hypogranular mast cells and hypergranular mast cells were similar to the control group during the whole study. However, degranulated mast cells showed a significant increase in perimeter and area values (p lt 0.05), while their roundness was decreased (p lt 0.05) in comparison to the control groups of animals. It could be concluded that the chosen quantitative morphometric parameters of cardiac degranular mast cells are useful for the evaluation of the functional status of the rats' heart during acute T-2 poisoning.Preživeli Wistar pacovi, tretirani T-2 toksinom (1 LD50; 0,23 mg/kg sc), žrtvovani su 1, 3, 5, 7, 14, 21. i 28. dana posle tretmana. U istim vremenskim intervalima žrtvovane su životinje iz kontrolnih grupa. Mastociti srca, prethodno obojeni primenom Giemsa metode bojenja, analizirani su u celom vidnom polju, pod uveličanjem 40. U ovom radu ispitivani su sledeći kvantitativni morfometrijski parametri: perimetar (P), površina (A) i kružnost (R). U srcu kontrolne grupe pacova mastocititi su većinom sitni (P = 6,86-7,99 mm), hipogranularni (A = 11,60 -14,30 mm2) i ovalnog oblika (R = 0,60-0,65 mm). Mastociti blago ispunjeni granulama, hipergranularni mastociti, imali su statistički značajno različite vrednosti kvantitativnih parametera (P = 12,80 -14,90 mm; A = 16,70 -20,00 mm2; R = 0,35-0,38 mm). Mali broj mastocita označeni kao deganulirani mastociti su veliki (P = 20,70-23,30 mm), nepravilnih oblika (A = 24,40 -30,90 mm2) sa granulama ispražnjenim u okolno tkivo (R = 0,15 -0,21 mm). U srcu pacova tretiranih T-2 toksinom kvantitativni parametari hipogranuliranih i hipergarnuliranih mastocita imali su vrednosti slične kontrolnim grupama životinja tokom celog perioda ispitivanja. Međutim, degranulirani mastociti pokazali su statistički značajno povećanje vrednosti prečnika i površine (p lt 0,05), dok je njihova kružnost bila manja (p lt 0,05) u poređenju sa kontrolnim grupama pacova. Moglo bi se zaključiti da su ispitivani kvantitativni morfometrijski parametri degranuliranih mastocita korisni za ispitivanje funkcionalnog statusa srca pacova akutno trovanih T-2 toksinom

Osmotic resistance of leucocytes in rats subjected to fractional X-ray exposure

Proučavana je osmotska rezistencija leukocita na pacovima podvrgnutim frakcioniranom, prolongiranom i intermitentnom ozračivanju X-zracima. Analiza rezultata pokazuje pad osmotske rezistencije kod zračenih životinja koji je statistički značajan u odnosu na kontrolnu grupu.Osmotic resistance of leucocytes was studied in rats exposed to fractional, prolonged and intermittent X-rays. Analysis of results indicated reduced osmotic resistance in irradiated animals which was statistically significant in relation to the control group

Geometric 3D Models of Spiral Structures Inspired by Contemporary Architecture

This geometric research is inspired by numerous magnificent structures-buildings around the world, which applied spiral geometry. Here we will present some of these architectural wonders and their basic geometric concepts. The intention of our work is to present the palette of 3D structures modeled in engineering software Auto CAD, where 3D operations with solids were available. Our concept concerning modeling of spiral building structures follows the basic geometric principles of simultaneous rotating and translating of an element along given geometric axis. The simple geometric shapes of circle, square, triangle and hexagon were combined in order to create the basic unit of spiral structure. We employed repetition of the basic unit, with the moving option in zigzag direction, around the central core (imaginary or real). Also, the combinations of elements which differ in sizes (scaling) are present in modeled shapes. As the result, we made various 3D models arranged in two types of structures: one developed in horizontal and the other in vertical direction

Carotenoids: New Applications of “Old” Pigments

Carotenoids represent a large group of mainly red, orange, and yellow natural metabolites mainly involved in regulation of many metabolic processes. Carotenoids are beneficial for human health. Current study describes the importance, chemical composition and functioning of carotenoids. It is well known that carotenoids support pigments acting in light absorbance mechanisms during photosynthesis, and are known to protect the chlorophyll molecules from oxidative stress and reactive oxygen species (ROS) damage. Carotenoids are involved in signaling processes in plants, responses to environmental stresses, pollination, germination and reproduction, and development regulation. As nutrients of strong antioxidant activity that is primarily linked to their polyene molecular structure, the carotenoids are reported as immune-enhancement and anticancer agents, which are also involved in prevention of eye-, gastric and neurocognitive disorders, and in regulation of obesity and anti-ageing. Concern-ing the wide prospective applications of carotenoids as pharmaceuticals and nutraceuticals, there are some critical aspects associated with carotenoids’ bioavailability and challenges in their bioengineering. This mostly refers to the needs for identification and cloning of genes responsible for carotenoid biosynthesis and transformation and related development of transgenic carotenoid-rich crops. In the recent years, technologies of micro-and nanoencapsulation have addressed the needs of carotenoid entrapping to enhance their bioavailability, solubility and chemical stability, and to ensure the target delivery and manifestation of their strong antioxidant and other biological activity. Among standard and some advanced analytic tools for carotenoid determination (e.g., High performance liquid chromatography-HPLC, Liquid chromatography–mass spectrometry-LC-MS, Ultra high performance liquid chromatography-UHPLC, High-performance thin-layer chromatography-HPTLC and others), the vibrational spectroscopy techniques, primarily Raman spectroscopy coupled with chemometric modeling, opened a new era in carotenoid research and application

Electrochemical performance of tin-based nano-composite electrodes using a vinylene carbonate-containing electrolyte for Li-ion cells

Tin represents a promising material to increase the specific capacity compared to the state of the art graphite anodes in lithium ion cells. The aim of this work is to explain the electrochemical behavior of tin based hydrocarbon nanoparticulate composite electrodes, synthesized by means of a microwave plasma technique without any binder or slurry process. A comprehensive electrochemical character ization shows that adding vinylene carbonate (VC) to the electrolyte improves the electrochemical performance. Electrochemical impedance spectroscopy (EIS) and post mortem investigations of the cycled electrode material by X ray photoelectron spectroscopy (XPS) reveal the formation of a polymeric SEI during the first cycles, being responsible for the improvement. The differential capacity plots of the discharging process show that the lithium richest phase (Li22Sn5) is formed during electrochemical loading. A comprehensive characterization with specially designed electrochemical tests finally dem onstrates the decrease of capacity with increasing temperature. This is due to intensified mechanical stresses and a fresh SEI formation. Due to destruction of the electrode material degradation is also observed with increasing current density. The SEI layer on the surface of the electrodes is confirmed by scanning electron microscopy (SEM) investigations and energy dispersive X ray spectroscopy (EDS) elemental mapping