Can the U.S. Get There from Here?

Climate change impacts in the United States are increasingly evident and come with steep economic and social costs. The frequency and intensity of extreme weather events has increased in recent years, bringing record-breaking heat, heavy precipitation, coastal flooding, severe droughts, and damaging wildfires.According to the National Oceanic and Atmospheric Administration (NOAA), weather-related damages in the United States were $60 billion in 2011, and are expected to be significantly greater in 2012.The mounting costs convey an unmistakable urgency to address climate change by reducing greenhouse gas emissions (GHGs). This report examines pathways for GHG reductions in the United States through actions taken at the federal and state levels without the need for new legislation from the U.S. Congress

On the Semantics of Snapshot Isolation

Snapshot isolation (SI) is a standard transactional consistency model used in databases, distributed systems and software transactional memory (STM). Its semantics is formally defined both declaratively as an acyclicity axiom, and operationally as a concurrent algorithm with memory bearing timestamps. We develop two simpler equivalent operational definitions of SI as lock-based reference implementations that do not use timestamps. Our first locking implementation is prescient in that requires a priori knowledge of the data accessed by a transaction and carries out transactional writes eagerly (in-place). Our second implementation is non-prescient and performs transactional writes lazily by recording them in a local log and propagating them to memory at commit time. Whilst our first implementation is simpler and may be better suited for developing a program logic for SI transactions, our second implementation is more practical due to its non-prescience. We show that both implementations are sound and complete against the declarative SI specification and thus yield equivalent operational definitions for SI. We further consider, for the first time formally, the use of SI in a context with racy non-transactional accesses, as can arise in STM implementations of SI. We introduce robust snapshot isolation (RSI), an adaptation of SI with similar semantics and guarantees in this mixed setting. We present a declarative specification of RSI as an acyclicity axiom and analogously develop two operational models as lock-based reference implementations (one eager, one lazy). We show that these operational models are both sound and complete against the declarative RSI model

Comparison of Three Physical Activity Measurement Tools to Assess Physical Activity Guideline Compliance in Children

Current physical activity recommendations suggest that children should have 60 minutes of moderate-to-vigorous physical activity (MVPA) per day. Purpose: The purpose of this study was to compare the ability of three different physical activity measurement tools to assess whether children were meeting physical activity recommendations. Methods: Physical activity was assessed for one week via accelerometer (ActiGraph GT3X), pedometer (New Lifestyles NL-1000), and for one day using a self report questionnaire (Self-Administered Physical Activity Checklist, or [SAPAC]) in thirty 5th-grade students. A total of 15 students, (11 ± 1 yrs; 11 female, 4 male) met compliance standards and were used for data comparisons. Minutes spent in MVPA per day were calculated from the SAPAC and accelerometer data using Sallis specifications and Freedson cut-points, respectively. Data from the SAPAC and accelerometers were compared with Centers for Disease Control and Prevention physical activity guidelines. Steps per day from the pedometers were compared with BMI referenced steps per day cut-point guidelines. All data are presented as mean ± SD. Results: SAPAC indicated MVPA of 460 ± 473 minutes per day. Accelerometer assessment indicated MVPA of 40 ± 15 minutes per day. Pedometer assessment indicated 8994 ± 3047 steps per day. Conclusions: Within this sample, 6% of subjects met minimum physical activity recommendations based on accelerometer data, whereas 20% met minimum physical activity recommendations using the pedometer. However, 100% of subjects met recommendations using the subjective self-report recall questionnaire. This pilot study indicates 5th-grade students dramatically over report estimated MVPA via self-report questionnaire. Therefore, objective physical activity assessment tools, such as accelerometers and pedometers may be better suited than self-report questionnaires to assess compliance with physical activity guidelines in 5th-grade students

Craniofacial Morphology in familial cases of cleft lip/palate: phenotypic heterogeneity and genetic predisposition in unaffected family members

Indiana University-Purdue University Indianapolis (IUPUI)This study investigated familial cases of cleft lip with or without cleft palate to determine whether the unaffected members of each family can be identified as gene carriers for the cleft trait. This research presumes that such carriers will have henotypic features identifiable by cephalometric analysis that are associated with an increased risk to cleft offspring. Using population genetics methodology, a pedigree analysis was made for each family member was assigned to one of four groups: (1) obligate normal, (2) affected, (3) carrier, and (4) unknown. LA and PA cephalographs were taken on each subject and a clinical oral-facial examination carried out on participating family members. Various anatomic landmarks located on the LA and PA films were digitized and from them, a total of 28 linear measurements were made. To eliminate the effect of sex and differential age responses, Z scores were calculated. Through univariate analysis, only one variable, NCR-MO, was shown to be significantly different between the two groups. This variable difference by itself is not adequate to differentiate those in the normal group from the carrier group. Even though only one variable was significant, other differences in the variables between these groups become obvious when the group variables were plotted as Z scores. Since Z scores are pure values with no limits (2--the number of standard deviations in a given variable differs from normal). Thereby, age-related growth differences were minimized. Further information is gained when these Z scores are plotted as pattern profiles, Figures 5-7. These profiles of mean Z scores for each variable pointed out areas of the face in which the differences were so great that specific anatomic areas appeared to be associated with one of the four groups. For example, gene carriers demonstrated specific alterations in facial height that might conceivably be used to discriminate that group from the other three groups. The family normals and carriers were then analyzed by using a stepwise multivariate analysis. By this approach, a discriminant function was generated consisting of six variables (three each from the lateral and frontal headplates), which proved to be significant in distinguishing an individual's phenotype. These variables define facial height, width and depth. The specific findings included a decrease in mid-facial height and depth along with an increased lower facial height and width in the gene carrier population as compared to the normals. The function then was used to predict group membership of the same two groups. Comparing this analytical prediction to that of the grouping system that resulted from the pedigree analysis, all but one individual was classified correctly in both the normal and carrier population. A discriminant score was also determined for the unknown population of family members which were defined as non-cleft blood relatives of cleft probands. Thus, they were a mixture of two types--those unaffected who carried a genetic liability for producing a cleft child and those unaffected who did not. A prediction of their placement into either the normal or carrier group was made with the discriminate function. One-third were classed in the normal group and two-thirds as gene carriers. The results of this study confirm that the phenotype of these unaffected family members designated as obligate gene carriers differs significantly from that of the family normals. This information is not only quite useful for genetic counselling but gives both a better understanding or the genetic control of clefting and can lead to molecular research to identify the specific gene in question

The role of second-neighbor effects in photoemission: Are silicon surfaces and interfaces special?

A widely used assignment scheme for Si 2p2p core-level photoemission studies of silicon oxidation relies solely on the formal oxidation state of the silicon. The tacit assumption of this assignment methodology is that second-neighbor effects have no measurable effect on observed Si 2p2p binding energies. In this letter, new experiments are combined with literature precedents to make the case that the second-neighbor effects play an important role in determining binding energy shifts. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70944/2/APPLAB-72-1-46-1.pd

Scintillators and Cherenkov detectors for the registration of 10.8 MeV gamma rays

© Published under licence by IOP Publishing Ltd. The identification of nitrogen by neutron activation has been utilized in both explosive detection and in-vivo metabolic analysis. The 10.8 MeV gamma ray line emitted by thermal neutron capture provides a unique signature, however, due to its high energy its registration is non-trivial. Conventional approaches have used large dense inorganic scintillators which inevitably entail considerable expense. We examine the capabilities of arrays of smaller scintillation detectors and the use of glass Cherenkov detectors as an alternative

Characterizing the Diverse Cells that Associate with the Developing Commissures of the Zebrafish Forebrain

During embryonic development of bilateral organisms, neurons send axons across the midline at specific points to connect the two halves of the nervous system with a commissure. Little is known about the cells at the midline that facilitate this tightly regulated process. We exploit the con served process of vertebrate embryonic development in the zebrafish model system to elucidate the identity of cells at the midline that may facilitate postoptic (POC) and anterior commissure (AC) development. We have discovered that three differentgfap+ astroglial cell morphologies persist in contact with pathfinding axons throughout commissure formation. Similarly, olig2+ progenitor cells occupy delineated portions of the postoptic and anterior commissures. These early olig2+ progenitors demonstrate glial-like morphologies despite the lack of a myelination marker. Moreover, we conclude that both the gfap+ and olig2+ progenitor cells give rise to neuronal populations in both the telencephalon and diencephalon. Interestingly, these varied cell populations showed significant developmental heterochrony between the telencephalon and diencephalon. Lastly, we also showed that fli1a+ mesenchymal cells migrate along the presumptive commissure regions before and during midline axon crossing. Furthermore, following commissure maturation, specific blood vessels formed at the midline of the POC and immediately ventral and parallel to the AC. This comprehensive account of the cellular populations that correlate with the timing and position of commissural axon pathfinding has supported the conceptual modeling and identification of the early forebrain architecture that may be necessary for proper commissure development