Remarks on the Arab Spring Symposium, Fall 2012 - Prof. Patrick O’Malley

Professor Patrick O\u27Malley discusses his time in Egypt, and on-the-ground relations between the U.S. and Egypt

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

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

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

Students who use drugs in high school are less likely to attend or complete college.

n recent years, students’ experiences of college have become much more diverse, with some delaying post-high school enrollment, and attending both 2 and 4 year institutions. In new research which uses national survey data, Megan E. Patrick, John E. Schulenberg and Patrick M. O’Malley give an overview of trends in college attendance and its influences. Among their results, they find that youth from two-parent families were more likely to graduate from a 4-year than a 2-year college, and that those who used cigarettes, marijuana, or other illicit drugs in high school were more likely to drop out

Facile interrogation of high-order epistasis between distal sites using next-generation sequencing

Deep mutational scanning (DMS) combines next-generation sequencing and protein engineering to construct sequence-function landscapes and rapidly identify fitness optima. Practical use of these landscapes requires identification of all mutations in each protein variant due to the potential effects of epistasis, the interdependence between residues resulting in non-additive phenotypes. This phenomenon plays an important role in protein evolution and is often a necessary step along the path towards protein fitness optima. However, current methods to assign distal mutations to their corresponding gene are work-intensive, costly, and introduce potential sources of error. To overcome these limitations, we introduce a method compatible with DMS that matches distal mutations to their corresponding gene without additional experimental steps. Using this approach to screen ~2,000,000 unique protein variants, we engineer a human G protein-coupled receptor with a 15-fold improvement in ligand binding affinity and observe prevalent epistasis between distal residues within the ligand binding pocket. Compared to variants containing only proximal substitutions, those harboring missense mutations in distal sites demonstrate significantly greater functional activity in our screen. This method can be applied immediately to all experiments using Illumina next-generation sequencing and provides a facile approach to illuminate complex mechanisms underlying key protein functions. Please click Additional Files below to see the full abstract

Strategies to engineer G protein-coupled receptor ligand binding properties

G protein-coupled receptors (GPCRs) comprise a family of integral membrane proteins that mediate eukaryotic cells\u27 responses to a wide array of extracellular signals. As a result of their ligand specificity, sensitivity, and capacity for signal transduction, GPCRs have great potential as biosensors for a wide range of molecules (e.g. toxins, value-added products, biomarkers for disease). Despite their inherent advantages, many GPCRs are difficult to express functionally and in high numbers within heterologous hosts such as yeast. Thus, there is a need to engineer functionally expressed GPCRs to bind ligands of interest with high affinities and specificities. Towards this end, we have optimized a high-throughput screening methodology to engineer variants of the human adenosine A2A receptor (hA2AR) with improved binding affinity towards a target ligand. Specifically, a fluorescent ligand binding assay was used in concert with fluorescence-activated cell sorting (FACS) to isolate yeast cells expressing desirable hA2AR mutants. After four rounds of sorting, we observed convergence of mutated residues towards a consensus sequence and a 3.5-fold increase in cellular mean fluorescence intensity upon incubation with fluorescent ligand. Additionally, we demonstrate the importance of vector choice and concomitant mitotic stability in influencing hA2AR yield and cellular homogeneity in yeast. The use of a mitotically stable integrating vector results in increased GPCR yield compared to non-integrating (i.e. centromeric and episomal) vectors. Yields of hA2AR are improved further by increasing vector integration frequency, where gene copy number is shown to have a greater effect on protein yield at lower relative copy numbers. Further, the growth of cells in raffinose-containing media prior to gene induction is shown to improve cellular homogeneity of yeast expressing hA2AR under the control of an inducible galactose promoter. In all, these results are envisioned to benefit both GPCR expression and engineering in yeast. The use of this platform to further evolve and isolate improved hA2AR variants is expected to generate mutants with even greater binding affinity and specificity towards ligands of interest. Please click Additional Files below to see the full abstract