The effects of wing inertial forces and mean stroke angle on the pitch stability of hovering insects

This paper discusses the wing inertial effects on stability of pitch motion of hovering insects. The paper also presents a dynamic model appropriate for using averaging techniques and discusses the pitch stability results derived from the model. The model is used to predict the body angle of five insect species during hover, which are in good agreement with the available experimental results from different literature. The results suggest that the wing inertia forces have a considerable effect on pitch dynamics of insect flight and should not be ignored in dynamic analysis of hovering insects. The results also suggest that, though the pitch stability of hovering insects is open-loop stable, it may not be vibrationally stabilized. Instead, the pitch stability is a balance of the moment of insect's weight and the aerodynamic moment due to flapping kinematics with a nonzero mean stroke angle. Experiments with a flapping wing device confirm this results. To clearly explain the used model and clarify the difference between vibrational and non-vibrational stabilization, first this paper discusses the vibrational control of a three-degree-of-freedom force-input pendulum with its pivot moving in a vertical plane.Comment: 21 pages, 9 figures, 4 table

Decreased expression of p73 in colorectal cancer

Introduction. The colorectal cancer (CRC) is one of the most frequent cancer in Poland and worldwide. This disease is characterized by distinct genetic alterations. p73 belongs to the p53 gene family; however, its role in the pathogenesis of CRC has not been completely understood. p73 gene encodes several mRNA variants and protein isoforms with its longest and fully functional p73a (mRNA) and TAp73a (protein) isoform. The aim of the study was to investigate p73 gene expression at the mRNA (p73a) and protein (TAp73a) levels in CRC. Material and methods. Small sections of the crc tumor tissue and macroscopically unchanged colon mucosa and submucosa from the dissection margin were collected from 23 patients diagnosed with CRC. p73 mRNA levels were measured by Real-time PCR (QPCR) method and the expression level of TAp73a protein was assessed by Western blotting (WB) and immunohistochemical (IHC) staining. Results. We found a 37% decrease in the level of p73a mRNA in neoplastically changed (tumor) compared with unchanged normal colon tissue from the surgical margin (p = 0.041). No correlations were found between mRNA levels in cancer tissue and clinical-pathological parameters. The semi-quantification of TAp73a protein revealed lower and higher TAp73a protein contents in 11/23 and 12/23 of tumor samples, respectively, when compared with the median value of TAp73a protein in normal colon tissue (p = 0.61). The level of TAp73a protein level was 5 times lower in poorly differentiated cancer cells (G3) in comparison to moderately differentiated ones (G2; p = 0.02). No statistically significant correlations were observed between the level of the TAp73a protein and clinical-pathological patients’ characteristics. The IHC analysis of TAp73a protein presence in CRC samples showed decreased immunoreactivity when compared with matched sections of the unchanged colon wall in 4/9 patients, similar intensity of the IHC reaction in 4/9 patients and increased immunoreactivity in 1/9 patients. The TAp73a protein was localized mainly in the cytoplasm of the cancer cells. No statistically significant correlations between IHC results and clinical-pathological features of the patients were found. Conclusions. The obtained results suggest that the p73 gene may play a role as a tumor suppressor in the CRC progression

Wrodzone i nabyte mechanizmy odporności komórkowej w patogenezie przewlekłych nieswoistych zapaleń jelit

Inflammatory bowel disease (IBD) is a group of chronic autoimmune conditions that include Crohn’s disease (CD) and ulcerative colitis (UC). The exact aetiology of IBD has not been fully elucidated yet, although it appears that the main pathogenic factor is abnormal response of the immune system against host microflora in genetically susceptible patients. Immunological processes underlying development of IBD include interactions between the cells of both innate and adaptive immune response. Novel advances in immunology demonstrate the role of imbalance between proinflammatory and regulatory mechanisms in the chronic inflammatory conditions. Recently described innate lymphoid cells and new subclasses of T helper cell (Th) and regulatory T cells (Treg) have joined the classical components of the immune system such as T cells, B cells, dendritic cells and macrophages. This review provides an over view of the most impor tant cellular components of the innate and the adaptive immune response involved in the pathogenesis of IBD. It also presents the role of interactions between cells of both systems, highlighting the role of IL-22, IL-23 and IL-17, in the development and progression of IBD. Described dependencies may contribute to the discovery of new treatment for this group of diseases.Przewlekłe nieswoiste zapalenia jelit (PNZJ; IBD) stanowią grupę autoimmunologicznych schorzeń obejmujących dwie główne jednostki kliniczne: chorobę Leśniowskiego-Crohna (CD) i wrzodziejące zapalenie jelita grubego (UC). Etiologia tych chorób nie została jeszcze w pełni wyjaśniona, jednak wydaje się, że główną przyczyną jest nadmierna aktywacja układu odpornościowego skierowana przeciwko antygenom naturalnej flory bakteryjnej jelit u osób predysponowanych genetycznie. Procesy immunologiczne leżące u podstaw patomechanizmów PNZJ obejmują interakcje pomiędzy komórkami zarówno odpowiedzi wrodzonej, jak i nabytej. W ostatnich latach do klasycznych elementów układu immunolo­gicznego, takich jak limfocyty T i B, komórki dendrytyczne i makrofagi, dołączyły tak zwane wrodzone komórki limfoidalne (ILC) oraz nowe podklasy limfocytów pomocniczych (Th) oraz regulatorowych (Treg). Niniejsza praca stanowi przegląd najistotniejszych elementów komórkowych wrodzonych i nabytych mechanizmów układu odpornościowego zaangażowanych w rozwój PNZJ. Wspomniane również zostały najważniejsze interakcje pomiędzy komórkami obu układów, ze szczególnym uwzględnieniem roli interleukin IL-22, IL-23 i IL-17 w etiologii PNZJ. Opisane patomechanizmy PNZJ mogą przyczynić się do odkrycia nowych możliwości leczenia tej grupy chorób

Optical Compensation for Night Myopia Based on Dark Focus and CA/C Ratio

Purpose. To determine whether individual differences in dark focus and convergence accommodation to convergence (CA/C) ratio can be used to prescribe the best optical correction for night myopia. Methods. The best correction for night myopia was obtained by measuring visual acuity and contrast sensitivity across a range of lens powers and luminances. Dark focus was measured with an infrared optometer, and CA/C ratio was measured with an infrared optometer and eyetracker. Only young subjects were used (mean age = 25.4 years). Results. Optimal lens power was significantly correlated with dark focus, regardless of CA/C ratio. However, the slope of the regression line relating lens power to dark focus was steeper for subjects with CA/C ratios less than 0.4 diopters/meter angle (D/MA, n = 7) than for subjects with CA/C ratios greater than 0.4 D/MA (n = 9). The mean CA/C ratio for the entire sample (n = 16) was 0.59 D/MA. The mean optimal lens power and dark focus were -0.79 and 0.74 D, respectively, for the low CA/C group, and -0.60 and 0.91 D, respectively, for the high CA/C group

Sibsonian and non-Sibsonian natural neighbour interpolation of the total electron content value

In radioastronomy the interferometric measurement between radiotelescopes located relatively close to each other helps removing ionospheric effects. Unfortunately, in case of networks such as LOw Frequency ARray (LOFAR), due to long baselines (currently up to 1500 km), interferometric methods fail to provide sufficiently accurate ionosphere delay corrections. Practically it means that systems such as LOFAR need external ionosphere information, coming from Global or Regional Ionospheric Maps (GIMs or RIMs, respectively). Thanks to the technology based on Global Navigation Satellite Systems (GNSS), the scientific community is provided with ionosphere sounding virtually worldwide. In this paper we compare several interpolation methods for RIMs computation based on scattered Vertical Total Electron Content measurements located on one thin ionospheric layer (Ionospheric Pierce Points—IPPs). The results of this work show that methods that take into account the topology of the data distribution (e.g., natural neighbour interpolation) perform better than those based on geometric computation only (e.g., distance-weighted methods).Peer ReviewedPostprint (published version

Ionosphere sounding for pre-seismic anomalies identification (INSPIRE): results of the project and perspectives for the short-term earthquake forecast

The INSPIRE project was dedicated to the study of physical processes and their effects in ionosphere which could be determined as earthquake precursors together with detailed description of the methodology of ionospheric pre-seismic anomalies definition. It was initiated by ESA and carried out by an international consortium. The full set of key parameters of the ionospheric plasma was selected based on the retrospective analysis of the ground-based and satellite measurements of pre-seismic anomalies. Using this classification the multi-instrumental database of worldwide relevant ionospheric measurements (ionosonde and GNSS networks, LEO-satellites with in situ probes including DEMETER and FORMOSAT/COSMIC ROC missions) was developed for the time intervals related to selected test cases. As statistical processing shows, the main ionospheric precursors appear approximately 5 days before the earthquake within the time interval of 30 days before and 15 days after an earthquake event. The physical mechanisms of the ionospheric pre-seismic anomalies generation from ground to the ionosphere altitudes were formulated within framework of the Lithosphere-Atmosphere- Ionosphere Coupling (LAIC) model. The processes of precursor’s development were analyzed starting from the crustal movements, radon emission and air ionization, thermal and atmospheric anomalies, electric field and electromagnetic emissions generation, variations of the ionospheric plasma parameters, in particular vertical TEC and vertical profiles of the electron concentration. The assessment of the LAIC model performance with definition of performance criteria for earthquake forecasting probability has been done in statistical and numerical simulation domains of the Global Electric Circuit. The numerical simulations of the earthquake preparation process as an open complex system from start of the final stage of earthquake preparation up to the final point–main shock confirms that in the temporal domain the ionospheric precursors are one of the most late in the sequence of precursors. The general algorithm for the identification of the ionospheric precursors was formalized which also takes into account the external Space Weather factors able to generate the false alarms. The importance of the special stable pattern called the “precursor mask” was highlighted which is based on self-similarity of pre-seismic ionospheric variations. The role of expert decision in pre-seismic anomalies interpretation for generation of seismic warning is important as well. The algorithm performance of the LAIC seismo-ionospheric effect detection module has been demonstrated using the L’Aquila 2009 earthquake as a case study. The results of INSPIRE project have demonstrated that the ionospheric anomalies registered before the strong earthquakes could be used as reliable precursors. The detailed classification of the pre-seismic anomalies was presented in different regions of the ionosphere and signatures of the pre-seismic anomalies as detected by ground and satellite based instruments were described what clarified methodology of the precursor’s identification from ionospheric multi-instrumental measurements. Configuration for the dedicated multiobservation experiment and satellite payload was proposed for the future implementation of the INSPIRE project results. In this regard the multi-instrument set can be divided into two groups: space equipment and ground-based support, which could be used for realtime monitoring. Together with scientific and technical tasks the set of political, logistic and administrative problems (including certification of approaches by seismological community, juridical procedures by the governmental authorities) should be resolved for the real earthquake forecast effectuation.In years 2014–2016 works were supported by the ESA Project “INSPIRE, ionosphere Sounding for Pre-seismic anomalies Identification Research (INSPIRE)” nr 4000,111,456/14/NL/ MV. The work is supported by the National Center for Research and Development, Poland, through Grant ARTEMIS (decision no. DWM/PL-CHN/97/2019, WPC1/ ARTEMIS/2019); The authors thank also the Ministry of Science and Higher Education (MSHE), Poland for granting funds for the Polish contribution to the International LOFAR Telescope “(MSHE decision no. DIR/ WK/2016/2017/05–1)” and for maintenance of the LOFAR PL-612 Baldy (MSHE decisions: no. 59/E-383/SPUB/SP/ 2019.1). This work is supported by the National Science Centre, Poland, through Grants 2017/25/B/ST10/00479 and 2017/27/B/ST10/02190.Peer ReviewedPostprint (published version

Observations of the Sun using LOFAR Baldy station

We report first results of solar spectroscopic observations carried out with the Baldy LOFAR (LOw-Frequency ARray) station, Poland from October 2016 to July 2017. During this time, we observed different types of radio emission: type I and type III radio bursts. Our observations show that the station is fully operational and it is capable to work efficiently in the single station mode for solar observations. Furthermore, in this paper we will briefly describe the observational technique and instrument capabilities and show some examples of first observations. (C) 2018 COSPAR. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Global monitoring of ionospheric weather by GIRO and GNSS data fusion

Prompt and accurate imaging of the ionosphere is essential to space weather services, given a broad spectrum of applications that rely on ionospherically propagating radio signals. As the 3D spatial extent of the ionosphere is vast and covered only fragmentarily, data fusion is a strong candidate for solving imaging tasks. Data fusion has been used to blend models and observations for the integrated and consistent views of geosystems. In space weather scenarios, low latency of the sensor data availability is one of the strongest requirements that limits the selection of potential datasets for fusion. Since remote plasma sensing instrumentation for ionospheric weather is complex, scarce, and prone to unavoidable data noise, conventional 3D-var assimilative schemas are not optimal. We describe a novel substantially 4D data fusion service based on near-real-time data feeds from Global Ionosphere Radio Observatory (GIRO) and Global Navigation Satellite System (GNSS) called GAMBIT (Global Assimilative Model of the Bottomside Ionosphere with Topside estimate). GAMBIT operates with a few-minute latency, and it releases, among other data products, the anomaly maps of the effective slab thickness (EST) obtained by fusing GIRO and GNSS data. The anomaly EST mapping aids understanding of the vertical plasma restructuring during disturbed conditionsPeer ReviewedPostprint (published version

Effect of temporal location of correction of monochromatic aberrations on the dynamic accommodation response

Dynamic correction of monochromatic aberrations of the eye is known to affect the accommodation response to a step change in stimulus vergence. We used an adaptive optics system to determine how the temporal location of the correction affects the response. The system consists of a Shack-Hartmann sensor sampling at 20 Hz and a 37-actuator piezoelectric deformable mirror. An extra sensing channel allows for an independent measure of the accommodation level of the eye. The accommodation response of four subjects was measured during a +/− 0.5 D step change in stimulus vergence whilst aberrations were corrected at various time locations. We found that continued correction of aberrations after the step change decreased the gain for disaccommodation, but increased the gain for accommodation. These results could be explained based on the initial lag of accommodation to the stimulus and changes in the level of aberrations before and after the stimulus step change. Future considerations for investigations of the effect of monochromatic aberrations on the dynamic accommodation response are discussed