REVISITING THE ROLE OF OBSERVATION SESSION DURATION ON PRECISE POINT POSITIONING ACCURACY USING GIPSY/OASIS II SOFTWARE

The accuracy of GPS precise point positioning (PPP) was previously modelled as a function of the observing session duration T. The NASA, JPL’s software GIPSY OASIS II (GOA-II) along with the legacy products was used to process the GPS data. The original accuracy model is not applicable anymore because JPL started releasing its products using new modelling and analysis strategies as of August 2007, and the legacy products are no longer available. The developments mainly comprise the new orbit and clock determination strategy, second order ionosphere modelling, and single station ambiguity resolution. Previously, the PPP accuracy was studied using v 4.0 of the GOA-II. The accuracy model showed coarser results compared to that of the relative positioning. Here, we processed the data of the International GNSS Service (IGS) stations to refine the accuracy of GOA-II PPP from version 6.3. Considering the above changes we refined the accuracy of PPP. First we modified the previous model used for the accuracy assessment. Then we tested out this model using straightforward polynomial and logarithmic models. The tests indicate the previous formulation still satisfactorily models the accuracy using refined coefficient values Sn = 7.8 mm, Se = 6.8 mm, Sv = 29.9 mm for T ≥ 2 h

High-Resolution Kinoform X-Ray Optics Printed via 405 nm 3D Laser Lithography

Efficient focusing of X-rays is essential for high-resolution X-ray microscopy. Diffractive X-ray optics called kinoforms offer the highest focusing efficiencies in theory. However, they have long remained unavailable due to their challenging nanofabrication. Recently, various X-ray optic geometries including kinoforms have been realized using 3D laser lithography at near-infrared wavelengths. As the smallest features (period) of the kinoform determines the resolving power, there is a natural drive to find ways to fabricate kinoforms with ever smaller features. Here, a custom-built 3D laser lithography setup with an excitation wavelength of 405 nm is used, which allows to half the smallest period of the kinoforms compared to previous work. A 40% improvement in scanning transmission X-ray microscopy image resolution, that is, a cutoff resolution of 145 nm, and an efficiency of 7.6% at 700 eV is achieved. A reconstructed pixel size of 18.5 nm, reaching the limit imposed by the design of the microscopy set-up, is demonstrated through ptychographic imaging of a magnetic sample which has a strongly reduced contrast mechanism. Moreover, X-ray lenses manufactured by 405 nm 3D laser lithography have the potential to become much less expensive than X-ray lenses made by other means

Resveratrol enhances prostate cancer cell response to ionizing radiation. Modulation of the AMPK, Akt and mTOR pathways

<p>Abstract</p> <p>Background</p> <p>Prostate cancer (PrCa) displays resistance to radiotherapy (RT) and requires radiotherapy dose escalation which is associated with greater toxicity. This highlights a need to develop radiation sensitizers to improve the efficacy of RT in PrCa. Ionizing radiation (IR) stimulates pathways of IR-resistance and survival mediated by the protein kinase Akt but it also activates the metabolic energy sensor and tumor suppressor AMP-Activated Protein Kinase (AMPK). Here, we examined the effects of the polyphenol resveratrol (RSV) on the IR-induced inhibition of cell survival, modulation of cell cycle and molecular responses in PrCa cells.</p> <p>Methods</p> <p>Androgen-insensitive (PC3), sensitive (22RV1) PrCa and PNT1A normal prostate epithelial cells were treated with RSV alone (2.5-10 μM) or in combination with IR (2-8 Gy). Clonogenic assays, cell cycle analysis, microscopy and immunoblotting were performed to assess survival, cell cycle progression and molecular responses.</p> <p>Results</p> <p>RSV (2.5-5 μM) inhibited clonogenic survival of PC3 and 22RV1 cells but not of normal prostate PNT1A cells. RSV specifically sensitized PrCa cells to IR, induced cell cycle arrest at G1-S phase and enhanced IR-induced nuclear aberrations and apoptosis. RSV enhanced IR-induced expression of DNA damage (γH2Ax) and apoptosis (cleaved-caspase 3) markers as well as of the cell cycle regulators p53, p21^cip1and p27^kip1. RSV enhanced IR-activation of ATM and AMPK but inhibited basal and IR-induced phosphorylation of Akt.</p> <p>Conclusions</p> <p>Our results suggest that RSV arrests cell cycle, promotes apoptosis and sensitizes PrCa cells to IR likely through a desirable dual action to activate the ATM-AMPK-p53-p21^cip1/p27^kip1and inhibit the Akt signalling pathways.</p

Metformin : on ongoing journey across diabetes, cancer therapy and prevention

Cancer metabolism is the focus of intense research, which witnesses its key role in human tumors. Diabetic patients treated with metformin exhibit a reduced incidence of cancer and cancer-related mortality. This highlights the possibility that the tackling of metabolic alterations might also hold promising value for treating cancer patients. Here, we review the emerging role of metformin as a paradigmatic example of an old drug used worldwide to treat patients with type II diabetes which to date is gaining strong in vitro and in vivo anticancer activities to be included in clinical trials. Metformin is also becoming the focus of intense basic and clinical research on chemoprevention, thus suggesting that metabolic alteration is an early lesion along cancer transformation. Metabolic reprogramming might be a very efficient prevention strategy with a profound impact on public health worldwide

AN APPLICATION OF ROLL-INVARIANT POLARIMETRIC FEATURES FOR CROP CLASSIFICATION FROM MULTI-TEMPORAL RADARSAT-2 SAR DATA

Crops are dynamically changing and time-critical in the growing season and therefore multitemporal earth observation data are needed for spatio-temporal monitoring of the crops. This study evaluates the impacts of classical roll-invariant polarimetric features such as entropy (H), anisotropy (A), mean alpha angle (&alpha;) and total scattering power (SPAN) for the crop classification from multitemporal polarimetric SAR data. For this purpose, five different data set were generated as following: (1) H&alpha;, (2) H&alpha;Span, (3) H&alpha;A, (4) H&alpha;ASpan and (5) coherency [T] matrix. A time-series of four PolSAR data (Radarsat-2) were acquired as 13 June, 01 July, 31 July and 24 August in 2016 for the test site located in Konya, Turkey. The test site is covered with crops (maize, potato, summer wheat, sunflower, and alfalfa). For the classification of the data set, three different models were used as following: Support Vector Machines (SVMs), Random Forests (RFs) and Naive Bayes (NB). The experimental results highlight that H&alpha;ASpan (91.43&thinsp;% for SVM, 92.25&thinsp;% for RF and 90.55&thinsp;% for NB) outperformed all other data sets in terms of classification performance, which explicitly proves the significant contribution of SPAN for the discrimination of crops. Highest classification accuracy was obtained as 92.25&thinsp;% by RF and H&alpha;ASpan while lowest classification accuracy was obtained as 66.99&thinsp;% by NB and H&alpha;. This experimental study suggests that roll-invariant polarimetric features can be considered as the powerful polarimetric components for the crop classification. In addition, the findings prove the added benefits of PolSAR data investigation by means of crop classification

High amp; 8208;Resolution Kinoform X Ray Optics Printed via 405 nm 3D Laser Lithography

Efficient focusing of X rays is essential for high resolution X ray microscopy. Diffractive X ray optics called kinoforms offer the highest focusing efficiencies in theory. However, they have long remained unavailable due to their challenging nanofabrication. Recently, various X ray optic geometries including kinoforms have been realized using 3D laser lithography at near infrared wavelengths. As the smallest features period of the kinoform determines the resolving power, there is a natural drive to find ways to fabricate kinoforms with ever smaller features. Here, a custom built 3D laser lithography setup with an excitation wavelength of 405 nm is used, which allows to half the smallest period of the kinoforms compared to previous work. A 40 improvement in scanning transmission X ray microscopy image resolution, that is, a cutoff resolution of 145 nm, and an efficiency of 7.6 at 700 eV is achieved. A reconstructed pixel size of 18.5 nm, reaching the limit imposed by the design of the microscopy set up, is demonstrated through ptychographic imaging of a magnetic sample which has a strongly reduced contrast mechanism. Moreover, X ray lenses manufactured by 405 nm 3D laser lithography have the potential to become much less expensive than X ray lenses made by other mean

DMSO and Betaine Greatly Improve Amplification of GC-Rich Constructs in De Novo Synthesis

In Synthetic Biology, de novo synthesis of GC-rich constructs poses a major challenge because of secondary structure formation and mispriming. While there are many web-based tools for codon optimizing difficult regions, no method currently exists that allows for potentially phenotypically important sequence conservation. Therefore, to overcome these limitations in researching GC-rich genes and their non-coding elements, we explored the use of DMSO and betaine in two conventional methods of assembly and amplification. For this study, we compared the polymerase (PCA) and ligase-based (LCR) methods for construction of two GC-rich gene fragments implicated in tumorigenesis, IGF2R and BRAF. Though we found no benefit in employing either DMSO or betaine during the assembly steps, both additives greatly improved target product specificity and yield during PCR amplification. Of the methods tested, LCR assembly proved far superior to PCA, generating a much more stable template to amplify from. We further report that DMSO and betaine are highly compatible with all other reaction components of gene synthesis and do not require any additional protocol modifications. Furthermore, we believe either additive will allow for the production of a wide variety of GC-rich gene constructs without the need for expensive and time-consuming sample extraction and purification prior to downstream application

Identification of Phosphoproteins as Possible Differentiation Markers in All-Trans-Retinoic Acid-Treated Neuroblastoma Cells

BACKGROUND: Neuroblastic tumors account for 9-10% of pediatric tumors and neuroblastoma (NB) is the first cause of death in pre-school age children. NB is classified in four stages, depending on the extent of spreading. A fifth type of NB, so-called stage 4S (S for special), includes patients with metastatic tumors but with an overall survival that approximates 75% at five years. In most of these cases, the tumor regresses spontaneously and regression is probably associated with delayed neuroblast cell differentiation. METHODOLOGY/PRINCIPAL FINDINGS: In order to identify new early markers to follow and predict this process for diagnostic and therapeutics intents, we mimicked the differentiation process treating NB cell line SJ-NK-P with all-trans-retinoic acid (ATRA) at different times; therefore the cell proteomic pattern by mass spectrometry and the phosphoproteomic pattern by a 2-DE approach coupled with anti-phosphoserine and anti-phosphotyrosine western blotting were studied. CONCLUSIONS/SIGNIFICANCE: Proteomic analysis identified only two proteins whose expression was significantly different in treated cells versus control cells: nucleoside diphosphate kinase A (NDKA) and reticulocalbin-1 (RCN1), which were both downregulated after 9 days of ATRA treatment. However, phosphoproteomic analysis identified 8 proteins that were differentially serine-phosphorylated and 3 that were differentially tyrosine-phosphorylated after ATRA treatment. All proteins were significantly regulated (at least 0.5-fold down-regulated). Our results suggest that differentially phosphorylated proteins could be considered as more promising markers of differentiation for NB than differentially expressed proteins

Estimation of stature from the foot and its segments in a sub-adult female population of North India

<p>Abstract</p> <p>Background</p> <p>Establishing personal identity is one of the main concerns in forensic investigations. Estimation of stature forms a basic domain of the investigation process in unknown and co-mingled human remains in forensic anthropology case work. The objective of the present study was to set up standards for estimation of stature from the foot and its segments in a sub-adult female population.</p> <p>Methods</p> <p>The sample for the study constituted 149 young females from the Northern part of India. The participants were aged between 13 and 18 years. Besides stature, seven anthropometric measurements that included length of the foot from each toe (T1, T2, T3, T4, and T5 respectively), foot breadth at ball (BBAL) and foot breadth at heel (BHEL) were measured on both feet in each participant using standard methods and techniques.</p> <p>Results</p> <p>The results indicated that statistically significant differences (p < 0.05) between left and right feet occur in both the foot breadth measurements (BBAL and BHEL). Foot length measurements (T1 to T5 lengths) did not show any statistically significant bilateral asymmetry. The correlation between stature and all the foot measurements was found to be positive and statistically significant (<it>p-value </it>< 0.001). Linear regression models and multiple regression models were derived for estimation of stature from the measurements of the foot. The present study indicates that anthropometric measurements of foot and its segments are valuable in the estimation of stature. Foot length measurements estimate stature with greater accuracy when compared to foot breadth measurements.</p> <p>Conclusions</p> <p>The present study concluded that foot measurements have a strong relationship with stature in the sub-adult female population of North India. Hence, the stature of an individual can be successfully estimated from the foot and its segments using different regression models derived in the study. The regression models derived in the study may be applied successfully for the estimation of stature in sub-adult females, whenever foot remains are brought for forensic examination. Stepwise multiple regression models tend to estimate stature more accurately than linear regression models in female sub-adults.</p