Analytic estimates and topological properties of the weak stability boundary

The weak stability boundary (WSB) is the transition region of the phase space where the change from gravitational escape to ballistic capture occurs. Studies on this complicated region of chaotic motion aim to investigate its unique, fuel saving properties to enlarge the frontiers of low energy transfers. This “fuzzy stability” region is characterized by highly sensitive motion, and any analysis of it has been carried out almost exclusively using numerical methods. On the contrary this paper presents, for the planar circular restricted 3 body problem (PCR3BP), 1) an analytic definition of the WSB which is coherent with the known algorithmic definitions; 2) a precise description of the topology of the WSB; 3) analytic estimates on the “stable region” (nearby the smaller primary) whose boundary is, by definition, the WSB

The evolution of the Line of Variations at close encounters: an analytic approach

We study the post-encounter evolution of fictitious small bodies belonging to the so-called Line of Variations (LoV) in the framework of the analytic theory of close encounters. We show the consequences of the encounter on the local minimum of the distance between the orbit of the planet and that of the small body and get a global picture of the way in which the planetocentric velocity vector is affected by the encounter. The analytical results are compared with those of numerical integrations of the restricted three-body proble

The course of the cystic artery during laparoscopic cholecystectomy

Proper recognition of the particular structures that form the triangle of Calot is essential for the proper and safe performance of laparoscopic cholecystectomy. Proper recognition, ligation, and cut of the cystic duct and cystic artery with branches (dorsal and ventral) remain an integral condition for the removal of the gallbladder. Calot’s triangle, as an orientation structure, determines the most common location of the cystic artery. The triangle of Calot is one of the most variable regions of the abdomen in terms of anatomy. The aim of this study was to evaluate how important for surgery is the detailed anatomical recognition of the main branches of the cystic artery in Calot’s triangle during laparoscopic cholecystectomy. Relations of the main branches of the cystic artery were evaluated in 88 patients that underwent laparoscopic cholecystectomy at the Department of General Surgery of the District Specialistic Hospital of Lublin. The anatomical relations of cystic duct and artery were classified into typical and variant types. Significantly more frequently variants of cystic artery were observed in women. However, the time of the procedure was not significantly related with the type of cystic artery

The Role of Citizen Science in Promoting Ocean and Water Literacy in School Communities: The ProBleu Methodology

Human activities continue to degrade oceanic, coastal and inland waters. The generational change in the role of society in actively looking after the health of water resources can be achieved through the expansion of ocean and water literacy in schools. The Network of European Blue Schools established under the EU4Ocean Coalition for Ocean Literacy has improved ocean and water literacy; however, this Network needs to grow and be supported. Here, we present ProBleu, a recently funded EU project that will expand and support the Network, partly through the use of citizen science. The core of the proposed methodology is facilitating school activities related to ocean and water literacy through funding calls to sustain and enrich current school activities, and kick-start and support new activities. The outcomes of the project are anticipated to have widespread and long-term impacts across society, and oceanic, coastal and inland water environments

AN EXPERIMENT FOR ZSCAN EFFICIENCY IN SURFACE MONITORING

Several geophysical processes, involving crustal deformation, can be studied and monitored by means of the comparison of multitemporal Digital Terrain Models (DTM) and/or Digital Surface Models (DSM): deformation patterns, displacements, surface variations, volumes involved in mass movements and other physical features can be observed and quantified providing useful information on the geomorphological variations (Butler et al., 1998; Kaab and Funk, 1999; Mora et al., 2003; van Westen and Lulie Getahun, 2003; Pesci et al., 2004; Fabris and Pesci, 2005; Baldi et al., 2005; Pesci et al., 2007; Baldi et al., 2008). Many techniques, including GPS kinematic methodology (Beutler et al., 1995), digital aerial and terrestrial photogrammetry (Kraus, 1998), airborne and terrestrial laser scanning (Csatho et al., 2005), remote sensors on space-borne platforms, both optical and radar stereo option, satellite SAR interferometry (Fraser et al., 2002), are suitable surveying methods for the acquisition of precise and reliable 3D or 2.5D geoinformation. Actually, the technique to capture the evolution of a natural process, rapidly changing the terrain morphology of an area like a volcanic eruption or a rock mass collapse, taking a time of a few seconds or several hours (or more) is the digital photogrammetry. Scientific software exist to manage and process stereoscopic photogrammetric images, requiring professional operators but, recently, more friendly applications are developed to facilitate and make fast but efficient the analysis

Survey of highly non-Keplerian orbits with low-thrust propulsion

Celestial mechanics has traditionally been concerned with orbital motion under the action of a conservative gravitational potential. In particular, the inverse square gravitational force due to the potential of a uniform, spherical mass leads to a family of conic section orbits, as determined by Isaac Newton, who showed that Kepler‟s laws were derivable from his theory of gravitation. While orbital motion under the action of a conservative gravitational potential leads to an array of problems with often complex and interesting solutions, the addition of non-conservative forces offers new avenues of investigation. In particular, non-conservative forces lead to a rich diversity of problems associated with the existence, stability and control of families of highly non-Keplerian orbits generated by a gravitational potential and a non-conservative force. Highly non-Keplerian orbits can potentially have a broad range of practical applications across a number of different disciplines. This review aims to summarize the combined wealth of literature concerned with the dynamics, stability and control of highly non-Keplerian orbits for various low thrust propulsion devices, and to demonstrate some of these potential applications

Laparoscopic treatment of bowel endometriosis in infertile women.

BACKGROUND: The purpose of the study was to determine the influence of bowel endometriosis on fertility, and to study whether its removal improves fecundity in women with endometriosis-associated infertility. METHODS: Three groups of infertile patients were included in the study. Group A (60 women) consisted of patients who underwent surgery for endometriosis with colorectal segmental resection. In group B, 40 patients with evidence of bowel endometriosis underwent endometriosis removal without bowel resection. Group C consisted of 55 women who underwent surgery for moderate or severe endometriosis with at least one endometrioma and deep infiltrating endometriosis but without bowel involvement. The women were clinically evaluated before laparoscopy and then at 1 month, at 6 months and at each year up to 4 years after surgery. Main outcome measures were surgical complications as well as post-operative pregnancy rate, time to conception and monthly fecundity rate. RESULTS: The monthly fecundity rates (MFR) in groups A, B and C were 2.3, 0.84 and 3.95%, respectively. The difference in the MFR between groups was significant (P < 0.05). CONCLUSIONS: The presence of bowel infiltration by endometriosis seems to negatively influence the reproductive outcome in women with endometriosis-associated infertility. The complete removal of endometriosis with bowel segmental resection seems to offer better results in terms of post-operative fertility

Exploring mobility in Italian Neolithic and Copper Age communities

As a means for investigating human mobility during late the Neolithic to the Copper Age in central and southern Italy, this study presents a novel dataset of enamel oxygen and carbon isotope values (delta (18)Oca and delta (13)Cca) from the carbonate fraction of biogenic apatite for one hundred and twenty-six individual teeth coming from two Neolithic and eight Copper Age communities. The measured delta (18)Oca values suggest a significant role of local sources in the water inputs to the body water, whereas delta (13)Cca values indicate food resources, principally based on C-3 plants. Both delta (13)Cca and delta (18)Oca ranges vary substantially when samples are broken down into local populations. Statistically defined thresholds, accounting for intra-site variability, allow the identification of only a few outliers in the eight Copper Age communities, suggesting that sedentary lifestyle rather than extensive mobility characterized the investigated populations. This seems to be also typical of the two studied Neolithic communities. Overall, this research shows that the investigated periods in peninsular Italy differed in mobility pattern from the following Bronze Age communities from more northern areas

ECSA's Characteristics of Citizen Science: Explanation Notes

This explanation document provides an interpretation of and explanation for the characteristics document, which was kept short to make it useful to different stakeholders. In this document, the characteristics document is represented, with the original text in blue and an explanation in black