Impact force generator: self-synchronization and regularity of motion

Abstract Impacts in multibody mechanical systems are an object of interest for many scientists in the world. In this paper, we present a principle of operation of the impact force generator being an element of the rotor of the heat exchanger. In this machine, step disturbances of the rotational velocity of the generator cause rapid changes of the rotational velocity of the exchanger rotor, which leads to the intensi®cation of the heat exchange process. We show the phenomenon of self-synchronization, regular motion of the system, and in a special case: chaotic motion of the rotor.

Global forecasting of thermal health hazards: the skill of probabilistic predictions of the Universal Thermal Climate Index (UTCI)

Although over a hundred thermal indices can be used for assessing thermal health hazards, many ignore the human heat budget, physiology and clothing. The Universal Thermal Climate Index (UTCI) addresses these shortcomings by using an advanced thermo-physiological model. This paper assesses the potential of using the UTCI for forecasting thermal health hazards. Traditionally, such hazard forecasting has had two further limitations: it has been narrowly focused on a particular region or nation and has relied on the use of single ‘deterministic’ forecasts. Here, the UTCI is computed on a global scale,which is essential for international health-hazard warnings and disaster preparedness, and it is provided as a probabilistic forecast. It is shown that probabilistic UTCI forecasts are superior in skill to deterministic forecasts and that despite global variations, the UTCI forecast is skilful for lead times up to 10 days. The paper also demonstrates the utility of probabilistic UTCI forecasts on the example of the 2010 heat wave in Russia

1-methylnicotinamide and its structural analog 1,4-dimethylpyridine for the prevention of cancer metastasis

Background: 1-methylnicotinamide (1-MNA), an endogenous metabolite of nicotinamide, has recently gained interest due to its anti-inflammatory and anti-thrombotic activities linked to the COX-2/PGI2 pathway. Given the previously reported anti-metastatic activity of prostacyclin (PGI2), we aimed to assess the effects of 1-MNA and its structurally related analog, 1,4-dimethylpyridine (1,4-DMP), in the prevention of cancer metastasis. Methods: All the studies on the anti-tumor and anti-metastatic activity of 1-MNA and 1,4-DMP were conducted using the model of murine mammary gland cancer (4T1) transplanted either orthotopically or intravenously into female BALB/c mouse. Additionally, the effect of the investigated molecules on cancer cell-induced angiogenesis was estimated using the matrigel plug assay utilizing 4T1 cells as a source of pro-angiogenic factors. Results: Neither 1-MNA nor 1,4-DMP, when given in a monotherapy of metastatic cancer, influenced the growth of 4T1 primary tumors transplanted orthotopically; however, both compounds tended to inhibit 4T1 metastases formation in lungs of mice that were orthotopically or intravenously inoculated with 4T1 or 4T1-luc2-tdTomato cells, respectively. Additionally, while 1-MNA enhanced tumor vasculature formation and markedly increased PGI2 generation, 1,4-DMP did not have such an effect. The anti-metastatic activity of 1-MNA and 1,4-DMP was further confirmed when both agents were applied with a cytostatic drug in a combined treatment of 4T1 murine mammary gland cancer what resulted in up to 80 % diminution of lung metastases formation. Conclusions: The results of the studies presented below indicate that 1-MNA and its structural analog 1,4-DMP prevent metastasis and might be beneficially implemented into the treatment of metastatic breast cancer to ensure a comprehensive strategy of metastasis control

Genomic and Epigenomic Responses to Chronic Stress Involve miRNA-Mediated Programming

Stress represents a critical influence on motor system function and has been shown to impair movement performance. We hypothesized that stress-induced motor impairments are due to brain-specific changes in miRNA and protein-encoding gene expression. Here we show a causal link between stress-induced motor impairment and associated genetic and epigenetic responses in relevant central motor areas in a rat model. Exposure to two weeks of mild restraint stress altered the expression of 39 genes and nine miRNAs in the cerebellum. In line with persistent behavioural impairments, some changes in gene and miRNA expression were resistant to recovery from stress. Interestingly, stress up-regulated the expression of Adipoq and prolactin receptor mRNAs in the cerebellum. Stress also altered the expression of Prlr, miR-186, and miR-709 in hippocampus and prefrontal cortex. In addition, our findings demonstrate that miR-186 targets the gene Eps15. Furthermore, we found an age-dependent increase in EphrinB3 and GabaA4 receptors. These data show that even mild stress results in substantial genomic and epigenomic changes involving miRNA expression and associated gene targets in the motor system. These findings suggest a central role of miRNA-regulated gene expression in the stress response and in associated neurological function

Kartowanie UTCI w skali lokalnej (na przykładzie Warszawy)

W opracowaniu przedstawiono zróżnicowanie przestrzenne warunków biotermicznych w Warszawie. Jako miarę warunków biotermicznych zastosowano nowy wskaźnik obciążeń cieplnych człowieka UTCI. Do obliczenia wartości UTCI zastosowano uproszczoną formułę matematyczną: UTCI* = 3,21 + 0,872 · t + 0,2459 · Mrt - 2,5078 · v - 0,0176 · RH gdzie: t oznacza temperaturę powietrza (°C), Mrt - średnią temperaturę promieniowania (°C), v - prędkość wiatru 10 m nad gruntem (m·s⁻¹), a RH - wilgotność względną powietrza (%). Do wygenerowania map i wykonania analiz przestrzennych zastosowano program IDRISI Tajga. Zróżnicowanie przestrzenne UTCI* określono dla kilku scenariuszy pogodowych: - pochmurno (lub słonecznie), t = 10°C, RH= 50%, v = 8 m·s⁻¹, - pochmurno (lub słonecznie), t = 20°C, RH= 50%, v = 4 m-s⁻¹, - pochmurno (lub słonecznie), t = 30°C, RH= 80%, v = 2 m·s⁻¹. Stwierdzono wyraźny wpływ różnych typów użytkowania terenu na kształtowanie w ich obrębie warunków biotermicznych określonych za pomocą wskaźnika UTCI. Zróżnicowanie to jest szczególnie widoczne podczas pogody chłodnej i wietrznej oraz gorącej i wilgotnej. Wyróżniają się obszary leśno-parkowe, które łagodzą warunki chłodu oraz gorąca

Productive factors and efficiency of their utilization in the EU farms

The aim of this study is an analysis of the equipment in productive factors in the new regions against the background of regions in the old EU countries, and also an analysis of equipment in labour force, land and capital depending on the economic size of a farm. The analysis indicated that the regions of the new states (i.e. admitted on May 1, 2004) are characterized by a small economic size of farms, not exceeding 20 ESU. Doubling of labour efficiency in these farms requires very large investments, especially in current assets, to a smaller degree in fixed assets.Celem niniejszego opracowania jest analiza wyposażenia w czynniki wytwórcze nowych regionów na tle regionów starej Unii Europejskiej, a także analiza wyposażenia w siłą roboczą, ziemią oraz kapitał w zależności od siły ekonomicznej gospodarstw. Stwierdzono, że regiony państw nowoprzyjętych w wyniku rozszerzenia UE w 2004 r., w tym również Polski, odznaczają się niskim poziomem wielkości ekonomicznej gospodarstwa, nie przekraczającym 20 ESU. Podwojenie wydajności w tych regionach wymaga doinwestowania gospodarstw, zwłaszcza w kapitał obrotowy, w mniejszym stopniu w kapitał trwały