Behind at the Starting Line: Poverty Among Hispanic Infants

In this brief, authors Daniel Lichter, Scott Sanders, and Kenneth Johnson examine the economic circumstances of Hispanic infants using the Census Bureau’s American Community Survey annual microdata files from 2006 through 2010. They report that a disproportionate share of Hispanic infants start life’s race behind the starting line, poor and disadvantaged—an important finding because the proportion of all U.S. births that are Hispanic is growing rapidly. The poverty risk is especially high among rural Hispanic infants and those in new destinations. Despite higher poverty risks, Hispanic infants receive less governmental assistance. High Hispanic infant poverty has immediate and long-term consequences for infants and the nation. Failing to invest in families and children now has long-term consequences because early childhood poverty tends to set into motion a series of lifecycle disadvantages (such as insufficient parenting, bad neighborhoods, underfunded schools, and poor health care) that greatly increases the likelihood of poverty in adulthood. The authors conclude that whether today’s Hispanic children will assimilate into America’s economic mainstream is an open question, but the Hispanic infants who will help reshape America’s future require public policy attention now

Diagrammatic Coupled Cluster Monte Carlo

We propose a modified coupled cluster Monte Carlo algorithm that stochastically samples connected terms within the truncated Baker--Campbell--Hausdorff expansion of the similarity transformed Hamiltonian by construction of coupled cluster diagrams on the fly. Our new approach -- diagCCMC -- allows propagation to be performed using only the connected components of the similarity-transformed Hamiltonian, greatly reducing the memory cost associated with the stochastic solution of the coupled cluster equations. We show that for perfectly local, noninteracting systems, diagCCMC is able to represent the coupled cluster wavefunction with a memory cost that scales linearly with system size. The favorable memory cost is observed with the only assumption of fixed stochastic granularity and is valid for arbitrary levels of coupled cluster theory. Significant reduction in memory cost is also shown to smoothly appear with dissociation of a finite chain of helium atoms. This approach is also shown not to break down in the presence of strong correlation through the example of a stretched nitrogen molecule. Our novel methodology moves the theoretical basis of coupled cluster Monte Carlo closer to deterministic approaches.Comment: 31 pages, 6 figure

The Gig Academy: Naming the Problem and Identifying Solutions

Over the past few decades, workers (staff, faculty, postdocs, graduate students) in higher education face working conditions and employer relationships that are increasingly similar and exploitative. Higher education has seen the implementation, spread, and refinement of technologies of labor exploitation that have proliferated in the broader economy often termed the gig economy. In this article, we posit and articulate the features of the Gig Academy – a unique iteration of the gig economy. We first describe the shifts in employment structures that make up the Gig Academy. We then describe how this transformation of the academy has eroded community, shared governance, collective action and student experience and outcomes. Lastly we describe some ways that higher education change agents can resist this trend and help to turn the tide working within new forms of collective action. The ideas set forth here are reviewed in greater detail in our book – The Gig Academy

Quantum partially observable Markov decision processes

We present quantum observable Markov decision processes (QOMDPs), the quantum analogs of partially observable Markov decision processes (POMDPs). In a QOMDP, an agent is acting in a world where the state is represented as a quantum state and the agent can choose a superoperator to apply. This is similar to the POMDP belief state, which is a probability distribution over world states and evolves via a stochastic matrix. We show that the existence of a policy of at least a certain value has the same complexity for QOMDPs and POMDPs in the polynomial and infinite horizon cases. However, we also prove that the existence of a policy that can reach a goal state is decidable for goal POMDPs and undecidable for goal QOMDPs.National Science Foundation (U.S.) (Grant 0844626)National Science Foundation (U.S.) (Grant 1122374)National Science Foundation (U.S.) (Waterman Award

Shrinking binary and planetary orbits by Kozai cycles with tidal friction

At least two arguments suggest that the orbits of a large fraction of binary stars and extrasolar planets shrank by 1-2 orders of magnitude after formation: (i) the physical radius of a star shrinks by a large factor from birth to the main sequence, yet many main-sequence stars have companions orbiting only a few stellar radii away, and (ii) in current theories of planet formation, the region within ~0.1 AU of a protostar is too hot and rarefied for a Jupiter-mass planet to form, yet many "hot Jupiters" are observed at such distances. We investigate orbital shrinkage by the combined effects of secular perturbations from a distant companion star (Kozai oscillations) and tidal friction. We integrate the relevant equations of motion to predict the distribution of orbital elements produced by this process. Binary stars with orbital periods of 0.1 to 10 days, with a median of ~2 d, are produced from binaries with much longer periods (10 d to 10^5 d), consistent with observations indicating that most or all short-period binaries have distant companions (tertiaries). We also make two new testable predictions: (1) For periods between 3 and 10 d, the distribution of the mutual inclination between the inner binary and the tertiary orbit should peak strongly near 40 deg and 140 deg. (2) Extrasolar planets whose host stars have a distant binary companion may also undergo this process, in which case the orbit of the resulting hot Jupiter will typically be misaligned with the equator of its host star.Comment: Submitted to ApJ; 18 pages, 10 figure

Working poverty is a widespread but under-analyzed and poorly-measured problem in the US

Data and statistics are integral to policymakers in government trying to tackle problems such as working poverty. And yet, estimates of the proportion of working poor in the US vary from 2 to 19 percent. In new research, Brian C. Thiede, Daniel T. Lichter, and Scott R. Sanders seek to explain the variation in statistics around those in working poverty. They write that estimates about the magnitude of working poverty, and on its incidence among racial and ethnic groups can be sensitive to the often technical choices, often based on assumptions about how people get into poverty, made by those who are doing the estimating

Ransomware against Police: Diagnosis of Risk Factors via Application of Cyber-Routine Activities Theory

Technologically advanced hackers are able to commit a crime and leave undiscovered by the authorities. Recent increases in cyber-attacks utilizing technology known as ransomware are leaving police departments and other institutions in the serious situation of having to pay ransom to cybercriminals. The present study employs a Cyber-Routine Theoretical approach in explaining why ransomware victimization has become a viral phenomenon. Data were derived from the recent reported cases of ransomware attacks towards police departments in the U.S. and analyzed in order to build a victim profile. This study shows that online lifestyle and cybersecurity are the salient factors that contribute to the ransomware victimization. Future potential preventive measures and policies will be discussed