Mars Orbiter Laser Altimeter: Experiment summary after the first year of global mapping of Mars

The Mars Orbiter Laser Altimeter (MOLA), an instrument on the Mars Global Surveyor spacecraft, has measured the topography, surface roughness, and 1.064-μm reflectivity of Mars and the heights of volatile and dust clouds. This paper discusses the function of the MOLA instrument and the acquisition, processing, and correction of observations to produce global data sets. The altimeter measurements have been converted to both gridded and spherical harmonic models for the topography and shape of Mars that have vertical and radial accuracies of ~1 m with respect to the planet's center of mass. The current global topographic grid has a resolution of 1/64° in latitude × 1/32° in longitude (1 × 2 km^2 at the equator). Reconstruction of the locations of incident laser pulses on the Martian surface appears to be at the 100-m spatial accuracy level and results in 2 orders of magnitude improvement in the global geodetic grid of Mars. Global maps of optical pulse width indicative of 100-m-scale surface roughness and 1.064-μm reflectivity with an accuracy of 5% have also been obtained

Relative Intestine Length and Feeding Ecology of Freshwater Fishes

There is a significant relationship between the intestine length (Y) and total body length (X) for 11 species of freshwater fish (Y = 0.08X1.42). Sufficient variation exists about this relationship to indicate important differences among the species\u27 diets. The diets for each species, ranked on a Trophic Index scale determined from literature data, are negatively rank order correlated with the mean relative intestine lengths (rs = -0.67). There is no significant rank order correlation between the Trophic Indices determined from data on stomach contents and the mean relative intestine lengths for fish from a single creek

RE: Towards realistic and flexible advance care planning.

\u27Think Ahead\u27 is more than an advance care directive. It is this, but also a comprehensive end of life planning tool, facilitating the individual to engage with their family, friends and professionals to make and record a broad number of preferences regarding end of life. It particularly addresses issues known to be of concern to the Irish Public4. It is a citizen-led tool, developed from a prolonged process of engagement with the public, patients, and medical and legal professions. Its development has been informed with reference to the international peer reviewed literature, and by pragmatic studies conducted in the community setting, evaluating feasibility and acceptability to patients and to health care professionals

Biological observations in the marginal ice zone of the East Greenland Sea

The distribution of nutrients, phytoplankton and zooplankton was investigated during summer, 1983 in the marginal ice zone of the East Greenland Sea. Nutrient levels, especially inorganic nitrogen, were extremely low, and probably limited the growth of phytoplankton during this period. An ammonium maximum at the base of the euphotic zone, generally around 50 m, was found repeatedly and appeared to be controlled by active nitrogen regeneration and decreased ammonium uptake at low light levels. Chlorophyll a levels were elevated at the ice-edge, but were even higher in an area influenced by an eddy. Species of zooplankton were accurate indicators of the origin of the two major water masses in this area, and zooplanktonic biomass was similar to other polar regions. Calculations of their impact on phytoplankton distributions indicated that grazing losses resulting from ingestion by large copepads may have been small. The dynamics associated with mesoscale eddies appear to be important in introducing new nitrogen into the euphotic zone and structuring the distribution of plant biomass at the ice-edge of the East Greenland Sea

Combination of herbivore removal and nitrogen deposition increases upland carbon storage

© 2015 The Authors. Global Change Biology Published by John Wiley & Sons Ltd. Acknowledgements We thank Ruth Mitchell, Alison Hester, Bob Mardon, Eoghain Maclean, David Welch, National Trust for Scotland, Scottish Natural Heritage and the Woodland Trust for helping find appropriate exclosures and granting access permission. We thank Nick Littlewood and Antonio Lopez Nogueira for their assistance in the field and processing samples in the lab and Ron Smith and Tony Dore for providing N deposition data. SWS was funded by a BBSRC studentship.Non peer reviewedPublisher PD

Adsorption of the natural protein surfactant Rsn-2 onto liquid interfaces

To stabilize foams, droplets and films at liquid interfaces a range of protein biosurfactants have evolved in nature. Compared to synthetic surfactants, these combine surface activity with biocompatibility and low solution aggregation. One recently studied example is Rsn-2, a component of the foam nest of the frog Engystomops pustulosus, which has been predicted to undergo a clamshell-like opening transition at the air–water interface. Using atomistic molecular dynamics simulations and surface tension measurements we study the adsorption of Rsn-2 onto air–water and cyclohexane–water interfaces. The protein adsorbs readily at both interfaces, with adsorption mediated by the hydrophobic N-terminus. At the cyclohexane–water interface the clamshell opens, due to the favourable interaction between hydrophobic residues and cyclohexane molecules and the penetration of cyclohexane molecules into the protein core. Simulations of deletion mutants showed that removal of the N-terminus inhibits interfacial adsorption, which is consistent with the surface tension measurements. Deletion of the hydrophilic C-terminus also affects adsorption, suggesting that this plays a role in orienting the protein at the interface. The characterisation of the interfacial behaviour gives insight into the factors that control the interfacial adsorption of proteins, which may inform new applications of this and similar proteins in areas including drug delivery and food technology and may also be used in the design of synthetic molecules showing similar changes in conformation at interfaces

Students' mental prototypes for functions and graphs

This research study investigates the concept of function developed by students studying English A-level mathematics. It shows that, while students may be able to use functions in their practical mathematics, their grasp of the theoretical nature of the function concept may be tenuous and inconsistent. The hypothesis is that students develop prototypes for the function concept in much the same way as they develop prototypes for concepts in everyday life. The definition of the function concept, though given in the curriculum, is not stressed and proves to be inoperative, with their understanding of the concept reliant on properties of familiar prototype examples: those having regular shaped graphs, such as x2 or sin*, those often encountered (possibly erroneously), such as a circle, those in which y is defined as an explicit formula in x, and so on. Investigations reveal significant misconceptions. For example, threequarters of a sample of students starting a university mathematics course considered that a constant function was not a function in either its graphical or algebraic forms, and threequarters thought that a circle is a function. This reveals a wide gulf between the concepts as perceived to be taught and as actually learned by the students

Unemployment Insurance: Fix It and Fund It

During the 2020–2021 pandemic, the federal-state unemployment insurance (UI) system in the United States nearly reached the breaking point. The surge in joblessness was matched in history only by the Great Depression of the 1930s. Congress hurriedly crafted temporary pandemic benefit assistance programs to fill benefit and eligibility gaps in state-run UI programs, handing them off to capacity-starved state UI agencies that fitfully served millions of workers and employers. After years of policy neglect and contraction, state UI programs have low benefit recipiency, meager earnings replacement rates, and inadequate benefit financing. It is time for comprehensive federal UI reform legislation, which should require state lawmakers to improve program access, benefit adequacy, financing, and reemployment services to meet the challenges of the new labor market. In this paper, the authors offer essential elements for practical UI program reform that includes explicit sharing of program costs between business and labor