A Study on Species Relationships and Inheritance of Characters in Genus, Section, and Subsection Lactuca 1.

Interspecific crossability and F1 hybrid vigor, chromosome pairing, pollen stainability, and achene fertility were used to assess relationships among Lactuca aculeata Boiss. & Kotschy, L. altaica Fisch. 6c Mey., L. capensis Thunb., L. perennis L., L. saligna L., L. sativa L., L. serriola L., and L. virosa L. Lactuca sativa, L. serriola, L. altaica, and L. aculeata were fully intercompatible and belong in a species complex (L. sativa-L. serriola) which forms the core of Lactuca section L. subsection L. Lactuca saligna crossed with members of the L. sativa-L. serriola complex only when used as the female, some of the F1's had abnormal growth, but all had meiotic irregularities, and lower pollen stainability and achene fertility. Lactuca virosa did not cross with L. saligna, but when used as the female did produce hybrids with the L. sativa-L. serriola complex. The F1's had abnormal growth, many meiotic irregularities, and no pollen staining or achene fertility. Therefore, L. virosa is more distantly related to the L. sativa-L. serriola complex than is L. saligna. Neither L. capensis nor L. perennis crossed with any of the other species and are not in subsection Lactuca. Previously unreported characters segregated within the L. sativa-L. serriola complex. Yellow pollen color was dominant to white giving 9:7 and 3:1 ratios caused by two complementary loci (wp-1 and wp-2). Basal branching was dominant to non-branching giving 3:1 and 13:3 ratios caused by a dominant allele for branching (b-1) at one locus epistatic to a second locus with a dominant allele for non-branching (b-2). Extra lobe formation on leaf dorsal sides was caused by a new allele (JJ^) at the leaf lobing locus which was dominant to both lobed (I/) and unlobed (u). Bitterness was quantitative and segregated approximately 1/16 non-bitter suggesting at least two loci. Linkage was tested between the above loci and other loci for anthocyanin pigmentation, spines, achene color, leaf tip shape, and involucre position. The b-2 branching locus was linked with the leaf lobing locus and the locus for spines was linked with one anthocyanin locus. Crosses between L. saligna and the L. sativa-L. serriola complex, also segregated for previously unreported characters. Branching segregated 13:3. Pappus bristle width segregated 3:1 two-cell width to one-cell width. Anthocyanic anther sheaths segregated three with anthocyanin to one without

Combining a Tablet personal computer and screencasting for chemistry teaching

This article describes innovative use of a Tablet PC and screencasting in delivering chemistry lectures. Introducing such technological innovations as an aid to chemistry lecturing is shown to be of immense benefit to both lecturer and student alike. The Tablet PC provides a clear method of presenting technical information in a dynamic fashion catering to both lecturer and student needs. It also permits archiving of lectures „as delivered‟ to be achieved. Screencasting allows easy recording of the entire lecture and archiving for future viewing by the students. Student reaction to such innovations is universally extremely positive and the widespread adoption of these practices is to be encouraged

Combining screencasting and a Tablet PC to deliver personalised student feedback

In many large research intensive universities in the UK the ability to provide a personalised university learning experience for their students is providing a serious challenge. Based on the National Student Survey (NSS) data, the absence of focused personalised feedback is often a concern of students. Here we describe how we use the combination of modern technologies encompassing a Tablet PC and screencasting to provide a personalised feedback to our students on submitted coursework and tutorial example classes. The fundamentals and practicalities of this approach, in particular with regard to the physical sciences, are described and data from student attitudinal and informational surveys are presented

Inheritance of Resistance to Tomato Spotted Wilt Virus in Lettuce (Lactuca Sativa L.)

Tomato Spotted Wilt Virus (TSWV), a thrips transmitted virus disease with a wide host range, has become a major limiting factor in lettuce production in Hawaii. Symptoms of this disease on lettuce are necrotic spotting of young leaves, stunting, wilting, and death of the plant. The large host range of this disease has made it difficult to control. Genetic resistance might work, but there have been no reports of resistance in lettuce. Hartmann (personal communication) undertook a preliminary screening program for TSWV resistance and found six lines of lettuce 'Tinto', PI 167128, PI 342510, PI 342517, PI 342522, and PI 342526 that showed less infection with TSWV than the susceptible 'Manoa'. In this study the six lines that Hartmann found plus one more 'Batavia' were tested for TSWV resistance. Only two lines, 'Tinto' and PI 342517 showed significantly higher resistance than the susceptible 'Manoa'. These two resistant lines were crossed with 'Manoa' and each other to produce F1 and F2 seed. Results of testing the F1 and F2 plants suggest that 'Tinto' and PI 342517 have the same genes for resistance and that this resistance is controlled by a dominant or partially dominant gene complex

A resource for introducing molecular modelling into the undergraduate chemistry curriculum

Computational methods including molecular modelling are becoming an essential aspect of chemistry. As such there is a pressing need to introduce this methodology at the undergraduate level. In this communication we give our experience of developing an appropriate course using formal lectures and practical workshop sessions. The emphasis is on practical applications. While the essential background theoretical aspect is introduced it is recognised that overemphasis and reliance on theoretical understanding can discourage many students. Our approach is to treat molecular modelling similarly to spectroscopic interpretation where an intelligent interpretation of an NMR spectrum does not always require a deep appreciation of background NMR theory

A case study in model-driven synthetic biology

We report on a case study in synthetic biology, demonstrating the modeldriven design of a self-powering electrochemical biosensor. An essential result of the design process is a general template of a biosensor, which can be instantiated to be adapted to specific pollutants. This template represents a gene expression network extended by metabolic activity. We illustrate the model-based analysis of this template using qualitative, stochastic and continuous Petri nets and related analysis techniques, contributing to a reliable and robust design

When four months equal a year: An exploration of inconsistencies in students' monthly versus yearly reports of drug use

https://deepblue.lib.umich.edu/bitstream/2027.42/137903/1/occ9.pd

Fisher Waves and Front Roughening in a Two-Species Invasion Model with Preemptive Competition

We study front propagation when an invading species competes with a resident; we assume nearest-neighbor preemptive competition for resources in an individual-based, two-dimensional lattice model. The asymptotic front velocity exhibits power-law dependence on the difference between the two species' clonal propagation rates (key ecological parameters). The mean-field approximation behaves similarly, but the power law's exponent slightly differs from the individual-based model's result. We also study roughening of the front, using the framework of non-equilibrium interface growth. Our analysis indicates that initially flat, linear invading fronts exhibit Kardar-Parisi-Zhang (KPZ) roughening in one transverse dimension. Further, this finding implies, and is also confirmed by simulations, that the temporal correction to the asymptotic front velocity is of ${\cal O}(t^{-2/3})$.Comment: 8 pages, 5 figures; Papers on related work can be found at http://www.rpi.edu/~korniss/Researc

The impacts of response styles on black-white differences in self-esteem: An analysis of six samples of youth

https://deepblue.lib.umich.edu/bitstream/2027.42/137900/1/occ16.pd

Effects of price and access laws on teenage smoking initiation: A national longitudinal analysis.

https://deepblue.lib.umich.edu/bitstream/2027.42/137880/1/yes-access_laws.pd