Developing Leadership in a National Cohort of Secondary Biology Teachers: Uses of an On-Line Course Structure to Develop Geographically Distant Professional Learning Community

This report is a descriptive study of the role that on-line courses might have on the development of Professional Learning Communities (PLC’s) that support national leadership initiatives of participating high school biology teachers. The one hundred teachers involved in the Life Sciences for a Global Community (LSGC) Institute are expected not only to deepen their content knowledge, but also impact their district and state biology curricula. Additionally, the dispersion of Institute participants across the country presents a unique opportunity to develop, communicate. and implement a national coherent reform agenda. However, the geographic distance presents a barrier to collaborative design of leadership projects. Therefore, the LSGC Institute designed web-based, distance learning courses as a means for both the instruction and development of distant professional relationships

Population Dynamics on Complex Food Webs

In this work we analyse the topological and dynamical properties of a simple model of complex food webs, namely the niche model. In order to underline competition among species, we introduce "prey" and "predators" weighted overlap graphs derived from the niche model and compare synthetic food webs with real data. Doing so, we find new tests for the goodness of synthetic food web models and indicate a possible direction of improvement for existing ones. We then exploit the weighted overlap graphs to define a competition kernel for Lotka-Volterra population dynamics and find that for such a model the stability of food webs decreases with its ecological complexity.Comment: 11 Pages, 5 Figures, styles enclosed in the submissio

Long-term response of Sultana vines to harvest pruning

The effect of harvest-pruning of the grapevine cv. Sultana, i. e. severing from the vine at harvest time the canes which carry most of the fruiting shoots, was investigated in two experiments. After seven and five seasons respectively, yields of dried fruit had not decreased significantly on harvest-pruned vines, although there were trends towards lower yield and reduced vegetative growth. Compared with a standard 30 cm-wide trellis, 45 cm- or 90 cm-wide trellises did not affect vine performance significantly. Advantages of wide trellis to the harvest system based on harvest-pruning are discussed.It was concluded that harvest-pruning will not lead to increasingly severe reductions in productivity, but that losses of up to 15 per cent could possibly occur. Measures which may help to avoid such losses are described.Langzeitreaktion von Sultana-Reben auf den „Ernteschnitt"Von Reben der Sorte Sultana wurden zur Zeit der Traubenlese sämtliche Tragruten abgeschnitten, die ja die meisten fruchtenden Triebe besitzen. Die Auswirkungen dieses Holzschnittes, der die Einsparung von Handarbeit bei der Ernte bezweckt, wurden in zwei Versuchen geprüft. Nach sieben bzw. fünf Vegetationsperioden war die Rosinenausbeute an den zur Lese geschnittenen Reben nicht signifikant zurückgegangen, wenngleich Tendenzen zu geringerem Traubenertrag und vermindertem Holzzuwachs vorhanden waren.Gegenüber einer Standarddrahtrahmenerziehung mit einem Abstand von 30 cm zwischen den beiden Tragrutendrähten beeinflußte ein Drahtabstand von 45 oder 90 cm die Entwicklung der Reben nicht signifikant. Die Vorteile des weiten Drahtabstandes für das auf dem Holzschnitt basierende Erntesystem werden diskutiert. Es wird gefolgert, daß der Ernteschnitt nicht zu fortschreitenden schweren Ertragseinbußen führt, daß jedoch unter Umständen Verluste bis zu 15% auftreten können. Maßnahmen zu ihrer Vermeidung werden beschrieben

Effect of various combinations of trellis, pruning, and rootstock on vigorous Sultana vines

The combined effects of three trellis, three pruning, and three rootstock treatments were tested on vigorous Sultana vines (Vitis vinifera L.) growing in a lighttextured, nematode- and phylloxera-free, virgin soil of the Australian Murray Valley.Vines on Salt Creek rootstock outyielded vines on 1613 C rootstock or on their own roots by about 40 per cent during the first four cropping seasons after planting, which preceded the experiment, and by about 30 per cent during the four seasons of the experiment, because they had more and larger bunches.A wide, high trellis with two cane-wires 1.2 m apart and 1.5 m above ground level, a narrow, high trellis (0.3 m X 1.5 m) and a narrow, low trellis (0.3 m X 1.0 m) were compared. On the wide trellis, the foliage canopy was divided naturally into two halves. In the season following the trellis conversion, vines on the wide trellis yielded slightly better than those on either of the narrow trellises, possibly because there was less mould damage. In the subsequent seasons, the wide trellis was much more productive. lt produced 40 to 50 per cent more crop because the vines had more bunches with more berries per bunch, while the concentration of sugar or acids remained unaltered. The amount of pruning wood was also somewhat greater. For the three pruning treatments, vines were given 126, 196, or 266 nodes (i. e. 9, 14, or 19 canes of 14 nodes each). In the later years of the experiment, the lightest pruning level could not be maintained on the narrow trellis, and pruning weight tended to become smaller. Yield increased disproportionately with increasing nodenumber; a two-fold increase in the number of nodes led to only a 20 per cent increase in yield.There were few interactions between the trellis, pruning, and rootstock treatments. The beneficial effects of wide trellis, Salt Creek rootstock and of light pruning, at least up to the level of 196 nodes per vine, tended to be additive. Thus lightly pruned Sultana vines on Salt Creek rootstock grown on a wide trellis with split canopy produced twice as much fruit as the conventionally treated Sultana, i. e. an own-rooted vine with 126 nodes grown on a narrow, low trellis.lt is concluded that Sultanas benefit from wide trellis through an effect on bud fruitfulness which leacls to more berries per vine, and through better photosynthetic activity which allows f4ll maturation of this increased crop potential. The economic implications of using wicle trellises and Salt Creek rootstock are discussed.Der Einfluß verschiedener Kombinationen von Drahtrahmen, Rebschnitt und Unterlage auf starkwüchsige Sultana-RebenDer vereinte Einfluß von drei Drahtrahmen-Typen und drei Schnittarten auf wurzelechte Sultana-Reben und auf Sultana, gepfropft auf den Unterlagen Salt Creek und 1613 C, die in einem leichten, Nematoden- und Phylloxerafreien Urboden des australischen Murray-Bewässerungsgebietes wuchsen, wurde untersucht. Alle Resultate wurden der Varianzanalyse unterworfen.In den ersten vier Ertragsjahren nach der Pflanzung, die dem Versuch vorausgingen, war der Ertrag von Sultana auf Salt Creek um 40°/o höher als derjenige von wurzelechten oder auf 1613 C gepfropften Reben. In den folgenden vier Versuchsjahren betrug dieser Unterschied etwa 30°/o. Mehr und größere Trauben waren der Grund hierfür.Die drei Drahtrahmen hatten die folgenden Dimensionen: Ein weiter, hoher Rahmen mit zwei Drähten, die mit 1,2 m Abstand 1,5 m über dem Boden angebracht waren; ein enger, hoher Rahmen (0,3 m X 1,5 m) und ein enger, niedriger Rahmen (0,3 m X 1,0 m) mit einem weiteren Draht für das Blattwerk. Am weiten Drahtrahmen teilte sich das Blattwerk spontan in zwei Hälften. In der ersten Vegetationsperiode nach dem Erstellen der Drahtrahmen war der Ertrag am weiten Rahmen etwas besser, vermutlich wegen des geringeren Fäulnisbefalles. In den folgenden drei Vegetationsperioden brachten die Reben am weiten Drahtrahmen um 40 bis 50°/o höhere Erträge, da mehr und größere Trauben vorhanden waren, während Beerengröße, Zucker- und Säuregehalt unverändert blieben. Auch das Gewicht des Schnittholzes war etwas größer. Die Reben wurden zu 9, 14 oder 19 Tragruten von je 14 Knospen, demnach zu 126, 196 oder 266 Knospen, geschnitten. Am engen Drahtrahmen konnte man die höchste Knospenzahl in den letzten Jahren des Versuches nicht erhalten, und auch das Triebgewicht wurde kleiner. Im allgemeinen hatte die Verdopplung der Knospenzahl nur einen 20prozentigen Anstieg im Ertrag zur Folge.Wechselwirkungen zwischen den Behandlungsarten Drahtrahmen, Schnitt und Unterlage kamen nur vereinzelt vor. Die vorteilhaften Einflüsse von weitem Drahtrahmen, Salt Creek-Unterlage und von höheren Knospenzahlen, wenigstens bis zu 196 Knospen je Rebe, waren additiv. Infolgedessen war der Ertrag der zu 196 Knospen geschnittenen Sultana auf Salt Creek und auf weitem Rahmen zweimal so groß wie derjenige der wurzelechten Sultana auf engem Rahmen mit 126 Knospen.Es wird geschlossen, daß Sultanaknospen am weiten Drahtrahmen fruchtbarer sind und daß folglich im nächsten Jahr die Reben mehr Traubenbeeren tragen, die überdies durch Verbesserung der Photosynthese völlig ausreifen können. Die ökonomischen Verhältnisse für den Gebrauch von weiten Drahtrahmen werden diskutiert

Symptomatic Social Science: Reflexivity, Recognition and Redistribution in the GBCS

The article examines methodological and theoretical issues related to the GBCS. It acknowledges its importance for the public profile of sociology, whilst arguing that it needs to develop a better sense of what it stands for not only in terms of understanding societal changes, but contributing to human betterment. To achieve this it discusses the role of reflexivity in the GBCS with reference to position and disposition and accounts of its process. It then moves on to examine its normative basis in terms of an ‘existential analytics’ and suggests a series of ways in which it might advance its insights as the work develops

The Adelaide VHF radar: Capabilities and future plans

The VHF radar at Buckland Park, South Australia commenced operation in January, 1984. The radar is located adjacent to the 2-MHz ionospheric radar. The routine method for measuring horizontal wind velocity is the space antenna technique (SA) while the Doppler technique is used to measure vertical velocities. It is possible to swing the transmitting beam in the east-west plane, allowing Doppler measurements of the EW wind component

Benchmarking calculations of excitonic couplings between bacteriochlorophylls

Excitonic couplings between (bacterio)chlorophyll molecules are necessary for simulating energy transport in photosynthetic complexes. Many techniques for calculating the couplings are in use, from the simple (but inaccurate) point-dipole approximation to fully quantum-chemical methods. We compared several approximations to determine their range of applicability, noting that the propagation of experimental uncertainties poses a fundamental limit on the achievable accuracy. In particular, the uncertainty in crystallographic coordinates yields an uncertainty of about 20% in the calculated couplings. Because quantum-chemical corrections are smaller than 20% in most biologically relevant cases, their considerable computational cost is rarely justified. We therefore recommend the electrostatic TrEsp method across the entire range of molecular separations and orientations because its cost is minimal and it generally agrees with quantum-chemical calculations to better than the geometric uncertainty. We also caution against computationally optimizing a crystal structure before calculating couplings, as it can lead to large, uncontrollable errors. Understanding the unavoidable uncertainties can guard against striving for unrealistic precision; at the same time, detailed benchmarks can allow important qualitative questions--which do not depend on the precise values of the simulation parameters--to be addressed with greater confidence about the conclusions

A Multi-Level Fit-Based Quality Improvement Initiative to Improve Colorectal Cancer Screening in a Managed Care Population.

IntroductionColorectal cancer (CRC) is a common but largely preventable disease with suboptimal screening rates despite national guidelines to screen individuals age 50-75. Single-component interventions aimed to improve screening uptake only modestly improve rates; data suggest that multi-modal approaches may be more effective.MethodsWe designed, implemented, and evaluated the impact of a multi-modal intervention on CRC screening uptake among unscreened patients in a large managed care population. Patient-level components included a mailed letter with education about screening options and pre-colonoscopy telephone counseling. For providers, we facilitated communication of screening test results and work-flow for abnormal results. System-level modifications included establishment of a patient navigator, expedited work-up for abnormal results, and stream-lined colonoscopy scheduling. We measured the rate of screening uptake overall, screening uptake by modality, change in the proportion of the population screened, and positive fecal immunochemical test (FIT) follow-up rates in the 1-year study period.ResultsThere were 5093 patients in the intervention cohort. Of these, 33.2% participated in FIT or colonoscopy screening within 1 year of the mailing. A total of 1078 (21.2%) participants completed a FIT and 611 (12.0%) completed a screening colonoscopy. The screening rate in the managed care population increased from 65.1 to 76.6%. Fifty-nine patients (5.5%) had a positive FIT, of which 30 (50.8%) completed a diagnostic colonoscopy.ConclusionMulti-modal interventions can result in substantial improvement in CRC screening uptake in large and diverse managed care populations.Translational impactHealth systems should shift their focus from single-level to multi-level interventions when addressing barriers to CRC screening

Species Abundance Patterns in Complex Evolutionary Dynamics

An analytic theory of species abundance patterns (SAPs) in biological networks is presented. The theory is based on multispecies replicator dynamics equivalent to the Lotka-Volterra equation, with diverse interspecies interactions. Various SAPs observed in nature are derived from a single parameter. The abundance distribution is formed like a widely observed left-skewed lognormal distribution. As the model has a general form, the result can be applied to similar patterns in other complex biological networks, e.g. gene expression.Comment: 4 pages, 3 figures. Physical Review Letters, in pres