Hybrid Direct-Indirect Strategy for Optimal Landing Guidance of Reusable Rockets

The present work focuses on developing a fast and accurate algorithm to find feasible trajectories for reusable rockets’ landing while minimizing their fuel consumption. Trajectory exploits aerodynamic forces, thus an Optimal Aerodynamic Powered Landing Problem is faced. A hybrid strategy is adopted, combining convex direct optimization with a novel indirect collocation scheme. A Covector Mapping Theorem is exploited to bridge the two methods. Development of the algorithm is organized in two steps: firstly, the structure of the optimal solution is derived solving the problem with a single shooting indirect method combined with a double homotopic continuation scheme; in second instance, an algorithm tailored on the optimal solution structure is presented and discussed. The suggested strategy is finally compared with the homotopic continuation scheme considering accuracy and computational times. Outcome is a net superiority of the designed algorithm over the homotopic technique; the power of a hybrid approach is therefore demonstrated over traditional solution methods

Intrinsic and Extrinsic Connections of Tet3 Dioxygenase with CXXC Zinc Finger Modules.

Tet proteins are emerging as major epigenetic modulators of cell fate and plasticity. However, little is known about how Tet proteins are targeted to selected genomic loci in distinct biological contexts. Previously, a CXXC-type zinc finger domain in Tet1 was shown to bind CpG-rich DNA sequences. Interestingly, in human and mouse the Tet2 and Tet3 genes are adjacent to Cxxc4 and Cxxc10-1, respectively. The CXXC domains encoded by these loci, together with those in Tet1 and Cxxc5, identify a distinct homology group within the CXXC domain family. Here we provide evidence for alternative mouse Tet3 transcripts including the Cxxc10-1 sequence (Tet3(CXXC)) and for an interaction between Tet3 and Cxxc4. In vitro Cxxc4 and the isolated CXXC domains of Tet1 and Tet3(CXXC) bind DNA substrates with similar preference towards the modification state of cytosine at a single CpG site. In vivo Tet1 and Tet3 isoforms with and without CXXC domain hydroxylate genomic 5-methylcytosine with similar activity. Relative transcript levels suggest that distinct ratios of Tet3(CXXC) isoforms and Tet3-Cxxc4 complex may be present in adult tissues. Our data suggest that variable association with CXXC modules may contribute to context specific functions of Tet proteins

long term follow up of hepatitis c virus positive patients with persistently normal serum transaminases

Material and methods. This study prospectively evaluated the progression of liver disease in a group of anti-HCV-positive patients with persistently normal ALT levels (PNALT) who were HCV-RNA positive. Patients selected for this study were those who presented with PNALT according to the Italian Association for the Study of the Liver (AISF) criteria in the year 1995/96 and underwent liver biopsy. They were divided into two groups according to their ALT evolution. Forty-five patients were included in this study. Results. After a median follow-up time of 180 months twenty-five of them maintained PNALT, but two of these developed liver cirrhosis (LC) in a mean time of 174 and 202 months, respectively. Twenty patients had flares of ALT and three of them developed LC in a mean time of 162-178 months. Twelve of these patients underwent current antiviral treatment; six patients were SVR. At baseline, the 5 patients who progressed to LC had age and BMI significantly higher than patients without LC (P < 0.005 and P < 0.01, respectively). Grading (P < 0.006) and staging (P < 0.003) were also more severe at histology, while serum HDL-C levels were statistically lower (P < 0.002). Comparing patients with flares of transaminases with and without LC, we found a significant difference at baseline for age, BMI, HDL-C, grading and staging (P < 0.05; P < 0.01 and P < 0.003, respectively). Conclusion. In HCV-RNA positive patients associated with PNALT the grade of disease activity increased over the years in only half of patients and a higher degree of liver fibrosis at baseline was the major relevant factor for progression

Global DNA hypomethylation prevents consolidation of differentiation programs and allows reversion to the embryonic stem cell state.

DNA methylation patterns change dynamically during mammalian development and lineage specification, yet scarce information is available about how DNA methylation affects gene expression profiles upon differentiation. Here we determine genome-wide transcription profiles during undirected differentiation of severely hypomethylated (Dnmt1⁻/⁻) embryonic stem cells (ESCs) as well as ESCs completely devoid of DNA methylation (Dnmt1⁻/⁻;Dnmt3a⁻/⁻;Dnmt3b⁻/⁻ or TKO) and assay their potential to transit in and out of the ESC state. We find that the expression of only few genes mainly associated with germ line function and the X chromosome is affected in undifferentiated TKO ESCs. Upon initial differentiation as embryoid bodies (EBs) wild type, Dnmt1⁻/⁻ and TKO cells downregulate pluripotency associated genes and upregulate lineage specific genes, but their transcription profiles progressively diverge upon prolonged EB culture. While Oct4 protein levels are completely and homogeneously suppressed, transcription of Oct4 and Nanog is not completely silenced even at late stages in both Dnmt1⁻/⁻ and TKO EBs. Despite late wild type and Dnmt1⁻/⁻ EBs showing a much higher degree of concordant expression, after EB dissociation and replating under pluripotency promoting conditions both Dnmt1⁻/⁻ and TKO cells, but not wild type cells rapidly revert to expression profiles typical of undifferentiated ESCs. Thus, while DNA methylation seems not to be critical for initial activation of differentiation programs, it is crucial for permanent restriction of developmental fate during differentiation

Indagine, tramite fototrappolaggio su siti di attrazione, sulla distribuzione dei carnivori di medio-piccola taglia nelle Prealpi orientali del veneto: sviluppo di una metodica ripetibile (CARNIVORA)

Survey of small and medium-size Carnivores in the Eastern Venetian Prealps, based on camera-trapping in attraction sites: development of a replicable methodology.Ecological data, especially distribution, on medium and small-size Carnivores in the Veneto region appear to be scarce, poorly updated and of low quality. The present field survey was developed with the contribution of the Associazione Faunisti Veneti, within the framework of the Atlas of the Mammals of Veneto. The survey focused on four areas in the Eastern Prealps of the Veneto region (Alpago, Integral Nature Reserve Piaie Longhe-Millifret, Grappa Massif and Cesen-Col Visentin ridge). The survey employed two different methods: the collection of traces of presence of target mammals along predetermined transects (“naturalistic” method) and infrared camera trapping at baited sites. A total of four species of medium and small-sized carnivores were identified through this survey: Martes martes, Martes foina, Meles meles, Vulpes vulpes. Animals identified through camera trapping allowed a higher level of confidence in species determination with respect to the naturalistic method. Taking together both methods, Vulpes vulpes was the most frequently detected species (85), followed by Martes foina (42), M. martes (33) and Meles meles (3). Even though data are preliminary, the two mustelids (M. martes and M. foina) seem to be mutually exclusive (Grappa massif vs. Alpago), suggesting different ecological requirements for these two species that are considered sympatric

Repeated TACE in HCC after Fontan surgery and situs viscerum inversus: A case report

We describe the case of a 32-year-old man who developed a liver neoplasm due to previous Fontan surgery (FS) for a single ventricle anomaly and situs viscerum inversus. He was admitted to our hospital for suspected hepatocellular carcinoma during an Ultrasound (US) follow up. Computed tomography (CT) showed features of chronic liver disease and 7 cm hepatic nodule with arterial enhancement. Laboratory analyses documented preserved liver function and increased levels of alpha-fetoprotein. Trans-arterial-chemoembolization (TACE) was performed obtaining complete necrosis at 4 weeks of follow up and significant reduction of alpha-fetoprotein. The patient is currently in follow-up, being evaluated for further treatments and/or combined liver-heart transplantation. TACE is a therapeutic option for the treatment of patients with unresectable hepatocellular carcinoma (HCC) and with severe heart disease, like those submitted to FS and with also other vascular abnormalities like those correlated to situs viscerum inversus

Characterization of PvuRts1I endonuclease as a tool to investigate genomic 5–hydroxymethylcytosine

In mammalian genomes a sixth base, 5-hydroxymethylcytosine ( hm C), is generated by enzymatic oxidation of 5-methylcytosine ( m C). This discovery has raised fundamental questions about the functional relevance of hm C in mammalian genomes. Due to their very similar chemical structure, discrimination of the rare hm C against the far more abundant m C is technically challenging and to date no methods for direct sequencing of hm C have been reported. Here, we report on a purified recombinant endonuclease, PvuRts1I, which selectively cleaves hm C-containing sequences. We determined the consensus cleavage site of PvuRts1I as hm CN 11–12 /N 9–10 G and show first data on its potential to interrogate hm C patterns in mammalian genomes

Restricted mobility of Dnmt1 in preimplantation embryos: implications for epigenetic reprogramming

BACKGROUND: Mouse preimplantation development is characterized by both active and passive genomic demethylation. A short isoform of the prevalent maintenance DNA methyltransferase (Dnmt1S) is found in the cytoplasm of preimplantation embryos and transiently enters the nucleus only at the 8-cell stage. RESULTS: Using GFP fusions we show that both the long and short isoforms of Dnmt1 localize to the nucleus of somatic cells and the cytoplasm of preimplantation embryos and that these subcellular localization properties are independent of phosphorylation. Importantly, photobleaching techniques and salt extraction revealed that Dnmt1S has a very restricted mobility in the cytoplasm, while it is highly mobile in the nucleus of preimplantation embryos. CONCLUSION: The restricted mobility of Dnmt1S limits its access to DNA and likely contributes to passive demethylation and epigenetic reprogramming during preimplantationdevelopment

trabecular bone score tbs and bone metabolism in patients affected with type 1 neurofibromatosis nf1

In patients with neurofibromatosis type 1 (NF1), decreased bone mineral density (BMD) and low levels of 25-hydroxy vitamin D3 (25OHD) have been reported. Recently, the trabecular bone score (TBS) measurement has been proposed as index of bone microarchitecture and fracture risk. In 74 NF1 patients (48 females, 26 males, age 41 ± 12), we measured TBS and investigated clinical stage, lifestyle, vitamin D, serum bone turnover markers, vertebral and femoral BMD. A homogenous cohort of 61 healthy subjects was used as control group. TBS was lower in NF1 patients (1.266 ± 0.113 vs. 1.346 ± 0.105) without differences between sexes. No correlations with 25OHD, low exercise, low calcium intake, reduced sun exposure, and number of skin neurofibromas were observed. As expected, hypovitaminosis D was common (98.6%), as well as BMD reduction in hip and spine sites: In NF1 patients, bone texture evaluated by TBS was low in both sexes without any correlation with clinical or metabolic parameters, suggesting a direct role of the fibromin mutation