Low delta-V near-Earth asteroids: A survey of suitable targets for space missions

In the last decades Near-Earth Objects (NEOs) have become very important targets to study, since they can give us clues to the formation, evolution and composition of the Solar System. In addition, they may represent either a threat to humankind, or a repository of extraterrestrial resources for suitable space-borne missions. Within this framework, the choice of next-generation mission targets and the characterisation of a potential threat to our planet deserve special attention. To date, only a small part of the 11,000 discovered NEOs have been physically characterised. From ground and space-based observations one can determine some basic physical properties of these objects using visible and infrared spectroscopy. We present data for 13 objects observed with different telescopes around the world (NASA-IRTF, ESO-NTT, TNG) in the 0.4 - 2.5 um spectral range, within the NEOSURFACE survey (http://www.oa-roma.inaf.it/planet/NEOSurface.html). Objects are chosen from among the more accessible for a rendez-vous mission. All of them are characterised by a delta-V (the change in velocity needed for transferring a spacecraft from low-Earth orbit to rendez-vous with NEOs) lower than 10.5 km/s, well below the Solar System escape velocity (12.3 km/s). We taxonomically classify 9 of these objects for the first time. 11 objects belong to the S-complex taxonomy; the other 2 belong to the C-complex. We constrain the surface composition of these objects by comparing their spectra with meteorites from the RELAB database. We also compute olivine and pyroxene mineralogy for asteroids with a clear evidence of pyroxene bands. Mineralogy confirms the similarity with the already found H, L or LL ordinary chondrite analogues.Comment: 9 pages, 7 figures, to be published in A&A Minor changes by language edito

Selective gelation of N-(4-pyridyl)nicotinamide by copper(II) salts

We report the selective gelation properties of the copper(II) complexes of N-(4-pyridyl)nicotinamide (4PNA). The morphology of the xerogels was examined by scanning electron microscopy (SEM). The correlation between the X-ray powder diffraction (XRPD) pattern of the xerogels and the single crystal structure of the copper(II) acetate complex suggests that the single crystal X-ray data represent a good structural model for the gel fibers, and that gelation arises from the presence of a 1D hydrogen-bonded chain between gelator amide groups and coordinated anions, while the presence of strongly bound water in non-gelator systems results in the formation of more extensively hydrogen-bonded crystalline networks. The selective gelation of all the copper(II) salts compared to the other metal salts may be attributed to the Jahn–Teller distorted nature of copper(II), which weakens water binding in all copper(II) salts

The NEOShield-2 EU project: The Italian contribution

The NEOShield-2 (2015-2017) project has been recently approved by the European Commission in the framework of the Horizon 2020 programme with the aim i) to study specific technologies and instruments to conduct close approach missions to NEOs or to undertake mitigation demonstration, and ii) to acquire in-depth information of physical properties of the population of small NEOs (50-300 m), in order to design mitigation missions and assess the consequences of an impact on Earth. The Italian scientific community is widely involved in this project

Factors Affecting Surgical Waiting Time in Cancer Patients at Referral Hospitals of West Java Province

A challenge for hospitals in facing the high number of patient visits is to provide quality services. One of the vital services in dealing with patients, especially those who will have cancer surgery considering the high rate of mortality cancer, is an improvement in waiting time (WT). Waiting time for elective surgery is one indicator of service quality with a standard of ≤2 days. This research aimed to determine the average WT for surgery, influencing factors, and optimal queuing models. The method used was quantitative and qualitative methods applied to 207 samples with consecutive sampling at West Java Provincial Al-Ihsan Regional General Hospital Bandung from October to December 2016. The analysis used partial least squares (PLS). The results of the study showed that the average WT for surgery was 32 days. Factors that influence WT were inpatient rooms, number of medical personnel, condition of patients, and health insurance. The optimal queue model to reduce surgical waiting time are adding inpatient beds, oncologist doctor, and creating an online system for registration and confirmation of inpatient rooms and operating.   FAKTOR YANG MEMENGARUHI WAKTU TUNGGU OPERASI PASIEN KANKER DI RUMAH SAKIT RUJUKAN JAWA BARAT Tantangan bagi rumah sakit dalam menghadapi jumlah kunjungan pasien yang tinggi adalah mampu memberikan pelayanan berkualitas. Salah satu pelayanan signifikan bagi pasien kanker yang akan menjalani operasi adalah perbaikan waktu tunggu karena mortalitas pasien kanker yang tinggi. Waktu tunggu operasi elektif merupakan salah satu indikator mutu pelayanan dengan standar ≤2 hari. Penelitian bertujuan mengetahui waktu tunggu operasi rerata, faktor yang memengaruhi, dan model antrean yang optimal. Metode yang digunakan adalah kuantitatif dan kualitatif yang diterapkan pada 207 sampel secara consecutive sampling di RSUD Al-Ihsan Provinsi Jawa Barat Bandung dari Oktober hingga Desember 2016. Analisis menggunakan partial least squares (PLS). Hasil penelitian menunjukkan bahwa waktu tunggu operasi rerata adalah 32 hari. Faktor yang berpengaruh terhadap waktu tunggu operasi adalah ruang rawat inap, jumlah tenaga medis, kondisi pasien, dan jaminan kesehatan. Model antrean yang optimal untuk menurunkan waktu tunggu operasi adalah penambahan tempat tidur rawat inap, penambahan dokter spesialis bedah onkologi, serta pembuatan sistem daring untuk pendaftaran dan konfirmasi kesiapan ruang rawat inap dan ruang operasi

Search for spontaneous muon emission from lead nuclei

We describe a possible search for muonic radioactivity from lead nuclei using the base elements ("bricks" composed by lead and nuclear emulsion sheets) of the long-baseline OPERA neutrino experiment. We present the results of a Monte Carlo simulation concerning the expected event topologies and estimates of the background events. Using few bricks, we could reach a good sensitivity level.Comment: 12 pages, 4 figure

Body Image and Life Satisfaction in Amish, Catholic, and Non-Religious Women

Dissatisfaction with one's appearance is commonplace in Western women. Body image dissatisfaction is believed to be a consequence of societal emphases on appearance reinforced through norms and media. However, some Amish cultural values and norms differ from prevailing Western influences, which may result in a rate of body image dissatisfaction at variance within women. The following pilot study explores how religious affiliation and religiosity may relate to body image factors (body dissatisfaction, appearance investment, and body image coping strategies) and life satisfaction in Amish (n = 32), Catholic (n = 40), and non-religious (n = 40) women. Results show that the Amish women reported having more positive body image on several factors than Catholic women, but the same results were not always replicated in non-religious women. Specifically, non-religious women showed similar levels of body satisfaction in comparison to Amish women, although they demonstrated use of different body image coping strategies. Additionally, when comparing women's reported current versus ideal figure, all women showed a preference for a thinner ideal. As this pilot study's methodology is preliminary, our ability to draw definitive conclusions is limited: future research should address these methodological limitations. If results from this study are confirmed, research is needed that examines the specific aspects of the Amish culture that may be associated with higher rates of body image satisfaction

On time-parallel preconditioning for the state formulation of incremental weak constraint 4D-Var

Using a high degree of parallelism is essential to perform data assimilation efficiently. The state formulation of the incremental weak constraint four-dimensional variational data assimilation method allows parallel calculations in the time dimension. In this approach, the solution is approximated by minimising a series of quadratic cost functions using the conjugate gradient method. To use this method in practice, effective preconditioning strategies that maintain the potential for parallel calculations are needed. We examine approximations to the control variable transform (CVT) technique when the latter is beneficial. The new strategy employs a randomised singular value decomposition and retains the potential for parallelism in the time domain. Numerical results for the Lorenz 96 model show that this approach accelerates the minimisation in the first few iterations, with better results when CVT performs well

Randomised preconditioning for the forcing formulation of weak constraint 4D‐Var

There is growing awareness that errors in the model equations cannot be ignored in data assimilation methods such as four-dimensional variational assimilation (4D-Var). If allowed for, more information can be extracted from observations, longer time windows are possible, and the minimisation process is easier, at least in principle. Weak constraint 4D-Var estimates the model error and minimises a series of linear least-squares cost functions, which can be achieved using the conjugate gradient (CG) method; minimising each cost function is called an inner loop. CG needs preconditioning to improve its performance. In previous work, limited memory preconditioners (LMPs) have been constructed using approximations of the eigenvalues and eigenvectors of the Hessian in the previous inner loop. If the Hessian changes significantly in consecutive inner loops, the LMP may be of limited usefulness. To circumvent this, we propose using randomised methods for low rank eigenvalue decomposition and use these approximations to cheaply construct LMPs using information from the current inner loop. Three randomised methods are compared. Numerical experiments in idealized systems show that the resulting LMPs perform better than the existing LMPs. Using these methods may allow more efficient and robust implementations of incremental weak constraint 4D-Var

Photometric survey of 67 near-Earth objects

Context. The near-Earth object (NEO) population is a window into the original conditions of the protosolar nebula, and has the potential to provide a key pathway for the delivery of water and organics to the early Earth. In addition to delivering the crucial ingredients for life, NEOs can pose a serious hazard to humanity since they can impact the Earth. To properly quantify the impact risk, physical properties of the NEO population need to be studied. Unfortunately, NEOs have a great variation in terms of mitigation-relevant quantities (size, albedo, composition, etc.) and less than 15% of them have been characterized to date. Aims. There is an urgent need to undertake a comprehensive characterization of smaller NEOs (D < 300 m) given that there are many more of them than larger objects; their small sizes make them intrinsically fainter and therefore harder to study. One of the main aims of the NEOShield-2 project (2015-2017), financed by the European Community in the framework of the Horizon 2020 program, is therefore to retrieve physical properties of a wide number of NEOs in order to design impact mitigation missions and assess the consequences of an impact on Earth. Methods. We carried out visible photometry of NEOs, making use of the DOLORES instrument at the Telescopio Nazionale Galileo (TNG, La Palma, Spain) in order to derive visible color indexes and the taxonomic classification for each target in our sample. Results. We attributed for the first time the taxonomical complex of 67 objects obtained during the first year of the project. While the majority of our sample belong to the S-complex, carbonaceous C-complex NEOs deserve particular attention. These NEOs can be located in orbits that are challenging from a mitigation point of view, with high inclination and low minimum orbit intersection distance (MOID). In addition, the lack of carbonaceous material we see in the small NEO population might not be due to an observational bias alone

Characterisation of the main belt asteroid (223) Rosa: A proposed flyby target of ESA's JUICE mission

Context. The ESA JUICE space mission, on its way to study Jupiter's environment and icy moons, will pass twice through the main asteroid belt. For this reason, the possibility to perform an asteroid flyby has been investigated. Aims. We aim to gain insight into the physical properties of the outer main belt asteroid (223) Rosa, which has been proposed as a potential JUICE flyby target. Methods. We report new visible and near-infrared spectroscopic observations at different rotation phases. Additionally, we perform a literature review of all the available physical properties, such as diameter, albedo, mass, and rotational period. Results. We find that asteroid Rosa is an X-type asteroid that shows no significant spectral variability combining the new and literature spectroscopic data. Its large size and orbital semimajor axis in the outer main belt indicate that Rosa does not belong to the Themis family, while its albedo is only marginally compatible with the family. Rosa's estimated density is in agreement with those of other low-albedo X-type asteroids. Hence, we propose that Rosa is a planetesimal that accreted in the protoplanetary disk beyond the snow line