Length, Weight, and Yield in Channel Catfish, Lake Diane, MI

Background: Channel catfish (Ictalurus punctatus) are important to both commercial aquaculture and recreational fisheries. Little published data is available on length-weight relationships of channel catfish in Michigan. Though there is no record of public or private stocking, channel catfish appeared in Lake Diane between 1984 and 1995 and it has developed into an excellent fishery. 
Materials and Methods: Sport angling provided 38 samples which were weighed and measured (fork length). Fillets were also weighed. The best fit estimates of parameters a and b in the model, W(L) = aLb, were obtained by both linear least-squares (LLS) regression (log(W) = log(a) + b log(L)) and non-linear least-squares (NLLS) regression. Best-fit parameters of an improved model, W(L) = (L/L1)^b, were also determined by NLLS regression; the parameter L1 is the typical length of a fish weighing 1 kg. The resulting best-fit parameters, parameter standard errors, and covariances are compared between the two models. The average relative weight for this sample of channel catfish is also determined, along with the typical meat yield obtained by filleting. 
Results: NLLS regression yields parameter estimates of b = 3.2293 and a = 0.00522. The improved model yields the same estimate for the exponent, b, and a length estimate (parameter L1) of 45.23 cm. Estimates of uncertainty and covariance are smaller for the improved model, but the correlation coefficient is r = 0.995 in both cases. LLS regression produced different parameter values, a = 0.01356 and b = 2.9726, and a smaller correlation coefficient, r = 0.980. On average, catfish in the sample weighed 106.0% of the standard weight, (Brown et al.) and the linear regression (no slope) of fillet yield vs. total weight suggests a typical fillet yield of 28.1% with r = 0.989.
Conclusion: Most of the fish in the sample were above the standard weight, heavier than the 75th percentile for their length. Channel catfish are doing well in Lake Diane and the population is well matched to the food supply. Management should attempt to maintain current population levels. In this case, the improved length-weight model, W(L) = (L/L1)^b, provided lower uncertainties in parameter estimates and smaller covariance than the traditional model.
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Vocalizations of the Townsend chipmunk (Eutamias townsendii)

This study describes and analyzes the vocalizations of the Townsend chipmunk (Eutamias townsendii) in Oregon. Tape recordings of calls were collected primarily from Forest Park in Portland (Oregon) during 1970 and 1971, and sonograms of these recordings were produced. Findings were compared with those of Brand (1970) who investigated E. townsendii vocalizations in California. The prominent calls in the vocal repertoire of townsendii are the quist, the quirt, and the chipper. These calls all appear to be warning calls. The quist note is a a chevron-shaped (A) figure representing a sound which begins at a low frequency (1-2 KC), sharply rises to a peak at about 11 KC, and then drops sharply to the lower frequencies again. Quists are arranged into bursts, and bursts into sequences. The number of quists per burst and the frequency of the top of the note decreased significantly over time. The interval between burst increased significantly, while the interval between quists seems to increase over time. The variation in the quist rate and related character6istics between Oregon and California townsendii populations is probably a result of subspecific differences. There seems to be a trend in the sciurids from the specific vocal system (one definite meaning per call) of the forest dwellers towards the unspecific vocal systems of animal groups which live in the more open habitats. E. townsendii displays a specific vocal system in which each call seems to have a specific function

Development of an hp-version finite element method for computational optimal control

The purpose of this research effort was to begin the study of the application of hp-version finite elements to the numerical solution of optimal control problems. Under NAG-939, the hybrid MACSYMA/FORTRAN code GENCODE was developed which utilized h-version finite elements to successfully approximate solutions to a wide class of optimal control problems. In that code the means for improvement of the solution was the refinement of the time-discretization mesh. With the extension to hp-version finite elements, the degrees of freedom include both nodal values and extra interior values associated with the unknown states, co-states, and controls, the number of which depends on the order of the shape functions in each element. One possible drawback is the increased computational effort within each element required in implementing hp-version finite elements. We are trying to determine whether this computational effort is sufficiently offset by the reduction in the number of time elements used and improved Newton-Raphson convergence so as to be useful in solving optimal control problems in real time. Because certain of the element interior unknowns can be eliminated at the element level by solving a small set of nonlinear algebraic equations in which the nodal values are taken as given, the scheme may turn out to be especially powerful in a parallel computing environment. A different processor could be assigned to each element. The number of processors, strictly speaking, is not required to be any larger than the number of sub-regions which are free of discontinuities of any kind

Parallax and Distance Estimates for Twelve Cataclysmic Variable Stars

We report parallax and distance estimates for twelve more cataclysmic binaries and related objects observed with the 2.4m Hiltner telescope at MDM Observatory. The final parallax accuracy is typically about 1 mas. For only one of the twelve objects, IR Gem, do we fail to detect a significant parallax. Notable results include distances for V396 Hya (CE 315), a helium double degenerate with a relatively long orbital period, and for MQ Dra (SDSSJ155331+551615), a magnetic system with a very low accretion rate. We find that the Z Cam star KT Persei is physically paired with a K main-sequence star lying 15 arcsec away. Several of the targets have distance estimates in the literature that are based on the white dwarf's effective temperature and flux; our measurements broadly corroborate these estimates, but tend to put the stars a bit closer, indicating that the white dwarfs may have rather larger masses than assumed. As a side note, we briefly describe radial velocity spectroscopy that refines the orbital period of V396 Hya to 65.07 +- 0.08 min.Comment: Accepted for Astronomical Journal. 19 pages, no figure

Collaborative systems for enhancing the analysis of social surveys: the grid enabled specialist data environments

This paper describes a group of online services which are designed to support social survey research and the production of statistical results. The 'Grid Enabled Specialist Data Environment' (GESDE) services constitute three related systems which offer facilities to search for, extract and exploit supplementary data and metadata concerned with the measurement and operationalisation of survey variables. The services also offer users the opportunity to deposit and distribute their own supplementary data resources for the benefit of dissemination and replication of the details of their own analysis. The GESDE services focus upon three application areas: specialist data relating to the measurement of occupations; educational qualifications; and ethnicity (including nationality, language, religion, national identity). They identify information resources related to the operationalisation of variables which seek to measure each of these concepts - examples include coding frames, crosswalk and translation files, and standardisation and harmonisation recommendations. These resources constitute important supplementary data which can be usefully exploited in the analysis of survey data. The GESDE services work by collecting together as much of this supplementary data as possible, and making it searchable and retrievable to others. This paper discusses the current features of the GESDE services (which have been designed as part of a wider programme of ‘e-Science’ research in the UK), and considers ongoing challenges in providing effective support for variable-oriented statistical analysis in the social sciences

The Theory of Evolution is Not an Explanation for the Origin of Life

The propagation of misconceptions about the theory of biological evolution must be addressed whenever and wherever they are encountered. The recent article by Paz-y-Mino and Espinoza in this journal contained several such misconceptions, including: that biological evolution explains the origin of life, confusion between biological and cosmological evolution, and the use of the term “Darwinism,” all of which we address here. We argue that science educators, and biology educators particularly, must be aware of these (and other) misconceptions and work to remove them from their classrooms