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Aims. We present high-sensitivity and high spectral-resolution NOEMA observations of the Class 0/I binary system SVS13A, composed of the low-mass protostars VLA4A and VLA4B, with a separation of ~90 au. VLA4A is undergoing an accretion burst that is enriching the chemistry of the surrounding gas, which provides an excellent opportunity to probe the chemical and physical conditions as well as the accretion process. Methods. We observe the (12 K –11 K ) lines of CH 3 CN and CH 3 13 CN, the DCN (3–2) line, and the C 18 O (2–1) line toward SVS13A using NOEMA. Results. We find complex line profiles at disk scales that cannot be explained by a single component or pure Keplerian motion. By adopting two velocity components to model the complex line profiles, we find that the temperatures and densities are significantly different among these two components. This suggests that the physical conditions of the emitting gas traced via CH 3 CN can change dramatically within the circumbinary disk. In addition, combining our observations of DCN (3–2) with previous ALMA observations at high angular resolution, we find that the binary system (or VLA4A) might be fed by an infalling streamer from envelope scales (~700 au). If this is the case, this streamer contributes to the accretion of material onto the system at a rate of at least 1.4 × 10 −6 M ⊙ yr −1 . Conclusions. We conclude that the CH 3 CN emission in SVS13A traces hot gas from a complex structure. This complexity might be affected by a streamer that is possibly infalling and funneling material into the central region. 

Context. In the past few years, there has been a rise in the detection of streamers, asymmetric flows of material directed toward the protostellar disk with material from outside a star’s natal core. It is unclear how they affect the process of mass accretion, in particular beyond the Class 0 phase. Aims. We investigate the gas kinematics around Per-emb-50, a Class I source in the crowded star-forming region NGC 1333. Our goal is to study how the mass infall proceeds from envelope to disk scales in this source. Methods. We use new NOEMA 1.3 mm observations, including C 18 O, H 2 CO, and SO, in the context of the PRODIGE MPG – IRAM program, to probe the core and envelope structures toward Per-emb-50. Results. We discover a streamer delivering material toward Per-emb-50 in H 2 CO and C 18 O emission. The streamer’s emission can be well described by the analytic solutions for an infalling parcel of gas along a streamline with conserved angular momentum, both in the image plane and along the line-of-sight velocities. The streamer has a mean infall rate of 1.3 × 10 −6 M ⊙ yr− 1 , five to ten times higher than the current accretion rate of the protostar. SO and SO 2 emission reveal asymmetric infall motions in the inner envelope, additional to the streamer around Per-emb-50. Furthermore, the presence of SO 2 could mark the impact zone of the infalling material. Conclusions. The streamer delivers sufficient mass to sustain the protostellar accretion rate and might produce an accretion burst, which would explain the protostar’s high luminosity with respect to other Class I sources. Our results highlight the importance of late infall for protostellar evolution: streamers might provide a significant amount of mass for stellar accretion after the Class 0 phase. 

The employment settings for autistic individuals in the USA is grim. As more children are diagnosed with ASD, the number of adolescent and young adult with ASD will increase as well over the next decade. Based on reports, one of the main challenges in securing and retaining employment for individual with ASD is difficulty in communicating and working with others in workplace settings. Most vocational trainings focused on technical skills development and very few addresses teamwork skills development. In this study, we present the design of a collaborative virtual environment (CVE) that support autistic individual to develop their teamwork skills by working together with a partner in a shared virtual space. This paper described the CVE architecture, teamwork-based tasks design and quantitative measures to evaluate teamwork skills. A system validation was also carried out to validate the system design. The results showed that our CVE was able to support multiple users in the same shared environment, the tasks were tolerable by users, and all the quantitative measures are recorded accordingly. 

CBMS notes from a series of 10 Lectures by David Cox, with supplemental lectures by C. D'Andrea, A. Dickenstein, J. Hauenstein, H. Schenck, J. Sidman. Systems of polynomial equations can be used to model an astonishing variety of phenomena. This book explores the geometry and algebra of such systems and includes numerous applications. The book begins with elimination theory from Newton to the twenty-first century and then discusses the interaction between algebraic geometry and numerical computations, a subject now called numerical algebraic geometry. The final three chapters discuss applications to geometric modeling, rigidity theory, and chemical reaction networks in detail. Each chapter ends with a section written by a leading expert. 

We introduce ThreeDWorld (TDW), a platform for interactive multi-modal physical simulation. TDW enables the simulation of high-fidelity sensory data and physical interactions between mobile agents and objects in rich 3D environments. Unique properties include: real-time near-photo-realistic image rendering; a library of objects and environments, and routines for their customization; generative procedures for efficiently building classes of new environments; high-fidelity audio rendering; realistic physical interactions for a variety of material types, including cloths, liquid, and deformable objects; customizable avatars that embody AI agents; and support for human interactions with VR devices. TDW's API enables multiple agents to interact within a simulation and returns a range of sensor and physics data representing the state of the world. We present initial experiments enabled by TDW in emerging research directions in computer vision, machine learning, and cognitive science, including multi-modal physical scene understanding, physical dynamics predictions, multi-agent interactions, models that 'learn like a child', and attention studies in humans and neural networks. 

Abstract Proton radioactivity was discovered exactly 50 years ago. First, this nuclear decay mode sets the limit of existence on the nuclear landscape on the neutron-deficient side. Second, it comprises fundamental aspects of both quantum tunnelling as well as the coupling of (quasi)bound quantum states with the continuum in mesoscopic systems such as the atomic nucleus. Theoretical approaches can start either from bound-state nuclear shell-model theory or from resonance scattering. Thus, proton-radioactivity guides merging these types of theoretical approaches, which is of broader relevance for any few-body quantum system. Here, we report experimental measurements of proton-emission branches from an isomeric state in 54m Ni, which were visualized in four dimensions in a newly developed detector. We show that these decays, which carry an unusually high angular momentum, ℓ = 5 and ℓ = 7, respectively, can be approximated theoretically with a potential model for the proton barrier penetration and a shell-model calculation for the overlap of the initial and final wave functions. 

Linking South and North America via a South Atlantic high-performance Research & Education Network (REN) with the nations of Africa’s researchers, students, and knowledge sharing communities has become an increasingly strategic priority. Africa offers research and education communities with unique biological, environmental, geological, anthropological, and cultural resources. Research challenges in atmospheric and geosciences, materials sciences, tropical diseases, biology, astronomy, and other disciplines will benefit by enhancing the technological and social connections between the research and education communities of the U.S., Brazil / Latin America, and Africa. For many years, we have seen the dramatic benefits of high-performance networking in all areas of science and engineering. The Americas Africa Research and eduCation Lightpaths (AARCLight) project (NSF OAC-1638990) provided support for a grant to plan, design, and define a strategy for high capacity research and education network connectivity between the U.S. and West Africa. The study indicated a high level of enthusiasm to engage in collaborative research between the U.S., Brazil, and the African communities. There is collaborative interest in sharing network infrastructure resources in the US at AMPATH in Miami, in Fortaleza and Sao Paulo, Brazil where RedClara and ANSP connect at SouthernLight, and in Cape Town, South Africa. There is strong evidence of multiple ongoing domain science projects between the U.S., Brazil, and Africa that would benefit from a new South Atlantic link. The results of this planning grant successfully supported the need to light a 100G pathway using the South Atlantic Cable System (SACS) connecting to AmLight-ExP in Fortaleza, Brazil, and via the West African Cable System (WACS) cable to the Cape Town, South Africa open exchange point. Based on these findings, AmLight-ExP , a high-performance R&E network supported by a consortium of participants and funding from the NSF is the steward of the SACS 100G link. With collaborative support from UbuntuNet Alliance, RNP, SANReN, and others, AmLight is taking steps to make this first South Atlantic R&E network path available to connect all three continents. This critical infrastructure establishes a new South Atlantic route to integrate with AmLight-ExP, adding resiliency to the global R&E network fabric by adding a new path to Africa and Europe from the southern hemisphere. The SACS cable, shown on Figure 1 as a purple dashed line between Fortaleza, Brazil, and Luanda, Angola, is the first east - west subsea cable in the South Atlantic. We will leverage network infrastructure in the southern hemisphere that is available to the R&E community including spectrum on Monet committed to the AmLight-ExP linking Miami, Fortaleza and São Paulo; a 100G Ethernet link on SACS; TENET’s capacity on WACS; the R&E exchange point in Cape Town-ZAOXI operated by SANReN (South African National Research Network) and TENET connected to WACS and the Ubuntunet Alliance Network connecting East Africa; and the South America eXchange R&E exchange point (SAX) in Fortaleza, operated by RNP and connected via AmLight-ExP via Monet to São Paulo and Miami. The paper will present 1) the key partners in the AmLight-SACS collaboration, 2) the activation plan, 3) how the network will be instrumented for performance measurements, and to capture data for network analytics, and 4) science drivers that will benefit from the use of a South Atlantic network route between the U.S., South America and West Africa. 

Linking South and North America via a South Atlantic high-performance Research & Education Network (REN) with the nations of Africa’s researchers, students, and knowledge sharing communities has become an increasingly strategic priority. Africa offers research and education communities with unique biological, environmental, geological, anthropological, and cultural resources. Research challenges in atmospheric and geosciences, materials sciences, tropical diseases, biology, astronomy, and other disciplines will benefit by enhancing the technological and social connections between the research and education communities of the U.S., Brazil / Latin America, and Africa. For many years, we have seen the dramatic benefits of high-performance networking in all areas of science and engineering. The Americas Africa Research and eduCation Lightpaths (AARCLight) project (NSF OAC-1638990) provided support for a grant to plan, design, and define a strategy for high capacity research and education network connectivity between the U.S. and West Africa. The study indicated a high level of enthusiasm to engage in collaborative research between the U.S., Brazil, and the African communities. There is collaborative interest in sharing network infrastructure resources in the US at AMPATH in Miami, in Fortaleza and Sao Paulo, Brazil where RedClara and ANSP connect at SouthernLight, and in Cape Town, South Africa. There is strong evidence of multiple ongoing domain science projects between the U.S., Brazil, and Africa that would benefit from a new South Atlantic link. The results of this planning grant successfully supported the need to light a 100G pathway using the South Atlantic Cable System (SACS) connecting to AmLight-ExP in Fortaleza, Brazil, and via the West African Cable System (WACS) cable to the Cape Town, South Africa open exchange point. Based on these findings, AmLight-ExP , a high-performance R&E network supported by a consortium of participants and funding from the NSF is the steward of the SACS 100G link. With collaborative support from UbuntuNet Alliance, RNP, SANReN, and others, AmLight is taking steps to make this first South Atlantic R&E network path available to connect all three continents. This critical infrastructure establishes a new South Atlantic route to integrate with AmLight-ExP, adding resiliency to the global R&E network fabric by adding a new path to Africa and Europe from the southern hemisphere. The SACS cable, shown on Figure 1 as a purple dashed line between Fortaleza, Brazil, and Luanda, Angola, is the first east - west subsea cable in the South Atlantic. We will leverage network infrastructure in the southern hemisphere that is available to the R&E community including spectrum on Monet committed to the AmLight-ExP linking Miami, Fortaleza, and São Paulo; a 100G Ethernet link on SACS; TENET’s capacity on WACS; the R&E exchange point in Cape Town-ZAOXI operated by SANReN (South African National Research Network) and TENET connected to WACS and the Ubuntunet Alliance Network connecting East Africa; and the South America eXchange R&E exchange point (SAX) in Fortaleza, operated by RNP and connected via AmLight-ExP via Monet to São Paulo and Miami. The paper will present 1) the key partners in the AmLight-SACS collaboration, 2) the activation plan, 3) how the network will be instrumented for performance measurements, and to capture data for network analytics, and 4) science drivers that will benefit from the use of a South Atlantic network route between the U.S., South America, and West Africa. 

Sub-Saharan Africa is the fastest growing region of international Internet capacity in the world. Content in Sub-Saharan Africa is increasing: Microsoft is bringing two new data centers to South Africa, and Google and Akamai have been installing caches. The demand for content distribution within Sub-Saharan Africa is growing as the number of data centers and caches increase. Strategic placement of local compute, storage and networking is increasingly important in response to demands in local content distribution growth. Internet eXchange Points (IXPs) are resources that play a central role in interconnecting many networks. In addition, their role has been expanding in importance for bringing content closer to end users. For example, as content traffic continues to rise, IXPs are in the foreground of the peering issues between content providers and access networks. IXPs are considered a natural resource to evolve into a SDX, because they offer a physical location where multiple networks meet to exchange traffic and to peer (exchange routes). This paper presents a Software-Defined Exchange as a novel internetworking paradigm to facilitate content distribution. A SDX facilitates sharing of compute, storage and networking resources among multiple independent administrative domains, such as ISPs, CDNs, or NRENs. A survey of the most relevant SDX studies and use cases for a SDX, including content distribution, will be presented. Finally, deployment considerations and projects implementing SDXs will be discussed. 

Context. Protostellar jets are an important agent of star formation feedback, tightly connected with the mass-accretion process. The history of jet formation and mass ejection provides constraints on the mass accretion history and on the nature of the driving source. Aims. We characterize the time-variability of the mass-ejection phenomena at work in the class 0 protostellar phase in order to better understand the dynamics of the outflowing gas and bring more constraints on the origin of the jet chemical composition and the mass-accretion history. Methods. Using the NOrthern Extended Millimeter Array (NOEMA) interferometer, we have observed the emission of the CO 2–1 and SO N J = 5 4 –4 3 rotational transitions at an angular resolution of 1.0″ (820 au) and 0.4″ (330 au), respectively, toward the intermediate-mass class 0 protostellar system Cep E. Results. The CO high-velocity jet emission reveals a central component of ≤400 au diameter associated with high-velocity molecular knots that is also detected in SO, surrounded by a collimated layer of entrained gas. The gas layer appears to be accelerated along the main axis over a length scale δ 0 ~ 700 au, while its diameter gradually increases up to several 1000 au at 2000 au from the protostar. The jet is fragmented into 18 knots of mass ~10 −3 M ⊙ , unevenly distributed between the northern and southern lobes, with velocity variations up to 15 km s −1 close to the protostar. This is well below the jet terminal velocities in the northern (+ 65 km s −1 ) and southern (−125 km s −1 ) lobes. The knot interval distribution is approximately bimodal on a timescale of ~50–80 yr, which is close to the jet-driving protostar Cep E-A and ~150–20 yr at larger distances >12″. The mass-loss rates derived from knot masses are steady overall, with values of 2.7 × 10 −5 M ⊙ yr −1 and 8.9 × 10 −6 M ⊙ yr −1 in the northern and southern lobe, respectively. Conclusions. The interaction of the ambient protostellar material with high-velocity knots drives the formation of a molecular layer around the jet. This accounts for the higher mass-loss rate in the northern lobe. The jet dynamics are well accounted for by a simple precession model with a period of 2000 yr and a mass-ejection period of 55 yr.