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Abstract Deriving high-quality light curves for asteroids and other periodic sources from survey data is challenging owing to many factors, including the sparsely sampled observational record and diurnal aliasing, which is a signature imparted into the periodic signal of a source that is a function of the observing schedule of ground-based telescopes. In this paper we examine the utility of combining asteroid observational records from the Zwicky Transient Facility and the Transiting Exoplanet Survey Satellite, which are the ground- and space-based facilities, respectively, to determine to what degree the data from the space-based facility can suppress diurnal aliases. Furthermore, we examine several optimizations that are used to derive the rotation periods of asteroids, which we then compare to the reported rotation periods in the literature. Through this analysis we find that we can reliably derive the rotation periods for ∼85% of our sample of 222 objects that are also reported in the literature and that the remaining ∼15% are difficult to reliably derive, as many are asteroids that are insufficiently elongated, which produces a light curve with an insufficient amplitude and, consequently, an incorrect rotation period. We also investigate a binary classification method that biases against reporting incorrect rotation periods. We conclude the paper by assessing the utility of using other ground- or space-based facilities as companion telescopes to the forthcoming Rubin Observatory. 

Abstract The Solar system Notification Alert Processing System (snaps) is a Zwicky Transient Facility (ZTF) and Rubin Observatory alert broker that will send alerts to the community regarding interesting events in the solar system.snapsis actively monitoring solar system objects and one of its functions is to compare objects (primarily main belt asteroids) to one another to find those that are outliers relative to the population. In this paper, we use theSNAPShot1data set, which contains 31,693 objects from ZTF, and derive outlier scores for each of these objects.snapsemploys an unsupervised approach; consequently, to derive outlier rankings for each object, we propose four different outlier metrics such that we can explore variants of the outlier scores and add confidence to the outlier rankings. We also provide outlier scores for each object in each permutation of 15 feature spaces, between two and 15 features, which yields 32,752 total feature spaces. We show that we can derive population outlier rankings each month at Rubin Observatory scale using four Nvidia A100 GPUs, and present several avenues of scientific investigation that can be explored using population outlier detection. 

The axon guidance cue netrin-1 signals through its receptor DCC (deleted in colorectal cancer) to attract commissural axons to the midline. Variants in DCC are frequently associated with congenital mirror movements (CMMs). A CMM-associated variant in the cytoplasmic tail of DCC is located in a conserved motif predicted to bind to a regulator of actin dynamics called the WAVE (Wiskott-Aldrich syndrome protein–family verprolin homologous protein) regulatory complex (WRC). Here, we explored how this variant affects DCC function and may contribute to CMM. We found that a conserved WRC-interacting receptor sequence (WIRS) motif in the cytoplasmic tail of DCC mediated the interaction between DCC and the WRC. This interaction was required for netrin-1–mediated axon guidance in cultured rodent commissural neurons. Furthermore, the WIRS motif of Fra, theDrosophilaDCC ortholog, was required for attractive signaling in vivo at theDrosophilamidline. The CMM-associated R1343H variant of DCC, which altered the WIRS motif, prevented the DCC-WRC interaction and impaired axon guidance in cultured commissural neurons and inDrosophila. The findings reveal the WRC as a pivotal component of netrin-1–DCC signaling and uncover a molecular mechanism explaining how a human genetic variant in the cytoplasmic tail of DCC may lead to CMM. 

Abstract The Mekong River basin (MRB) is a transboundary basin that supports livelihoods of over 70 million inhabitants and diverse terrestrial-aquatic ecosystems. This critical lifeline for people and ecosystems is under transformation due to climatic stressors and human activities (e.g., land use change and dam construction). Thus, there is an urgent need to better understand the changing hydrological and ecological systems in the MRB and develop improved adaptation strategies. This, however, is hampered partly by lack of sufficient, reliable, and accessible observational data across the basin. Here, we fill this long-standing gap for MRB by synthesizing climate, hydrological, ecological, and socioeconomic data from various disparate sources. The data— including groundwater records digitized from the literature—provide crucial insights into surface water systems, groundwater dynamics, land use patterns, and socioeconomic changes. The analyses presented also shed light on uncertainties associated with various datasets and the most appropriate choices. These datasets are expected to advance socio-hydrological research and inform science-based management decisions and policymaking for sustainable food-energy-water, livelihood, and ecological systems in the MRB. 

Various climate, hydro-meteorological, ecological, and socio-economic datasets are synthesized and made available for the Mekong River Basin. The sources of each dataset are also mentioned in the associated readme file. Dam attribute data, inundation data, and Cambodia census data can be made available upon request to the authors. 

Abstract We present here the design, architecture, and first data release for the Solar System Notification Alert Processing System (SNAPS). SNAPS is a solar system broker that ingests alert data from all-sky surveys. At present, we ingest data from the Zwicky Transient Facility (ZTF) public survey, and we will ingest data from the forthcoming Legacy Survey of Space and Time (LSST) when it comes online. SNAPS is an official LSST downstream broker. In this paper we present the SNAPS design goals and requirements. We describe the details of our automatic pipeline processing in which the physical properties of asteroids are derived. We present SNAPShot1, our first data release, which contains 5,458,459 observations of 31,693 asteroids observed by ZTF from 2018 July to 2020 May. By comparing a number of derived properties for this ensemble to previously published results for overlapping objects we show that our automatic processing is highly reliable. We present a short list of science results, among many that will be enabled by our SNAPS catalog: (1) we demonstrate that there are no known asteroids with very short periods and high amplitudes, which clearly indicates that in general asteroids in the size range 0.3–20 km are strengthless; (2) we find no difference in the period distributions of Jupiter Trojan asteroids, implying that the L4 and L5 clouds have different shape distributions; and (3) we highlight several individual asteroids of interest. Finally, we describe future work for SNAPS and our ability to operate at LSST scale. 

The Arf-family GTPases can switch on a central actin regulator named the WAVE Complex to promote actin polymerization.