Can Combining Academic and Career-Technical Education Improve High School Outcomes in California?

Assesses strategies for improving high school graduation rates by combining college preparatory coursework with career-technical education, and discusses results and practical challenges. Includes profiles of career academies with combined curricula

Navigation, recruitment, foraging ecology and visual systems of the banded sugar ant, camponotus consobrinus

Each species inhabits a unique niche. These niches can be defined by biotic or abiotic factors and animals evolve adaptations and behaviours to successfully exploit their niche. In this study I explore the niche of the Banded Sugar Ant, Camponotus consobrinus. I characterise the daily activity of this species that forages along the branches of Eucalyptus trees, a complex 3D environment. This species is crepuscular/nocturnal thus exposed to both dim and bright ambient light conditions, and appears to time outbound foraging activity to sunset throughout the year, although much less rigidly coupled compared to previously studied sympatric Myrmecia pyriformis. Activity onset occurs as a burst in outbound foragers during sunset and twilight periods, with few individuals returning to and leaving the nest during the night. Most individuals return to the nest in the morning, as sunrise approaches. I conducted temperature tolerance experiments with the aim of testing whether temperature might be an additional factor affecting the activity onset in this species. Through displacement experiments I show that both inbound and outbound foragers exclusively attend to landmark information for navigation and my experiments demonstrate for the first time a species of ant that does not rely on path integration for navigation or a celestial compass. Interestingly, however, the search patterns of displaced foragers do clearly involve path integration. Camponotus consobrinus recruits by tandem running where a recruit closely follows a leader. I characterise this behaviour and show by displacing recruits that they attend to landmark information for navigation, as well as that recruited individuals can also be experienced foragers. Further, I document dynamically changing tandem pairs, that is, apparently solitary foragers joining a tandem leader if her previous recruit has lost contact. Lastly, I examine the functional anatomy of the apposition compound eyes of C. consobrinus with the aim of identifying adaptations that allow these ants to operate at extremely varying light levels. C. consobrinus possess large diameter rhabdoms (7.32um) typical of night-active hymenoptera, but comparatively small facet lenses (20.81 - 25.56um). Light flux to the rhabdom is controlled by a variable primary pigment cell pupil that narrows the light path to less than 1um diameter at high light intensities. I further present initial findings of newly emerged ants that show an almost complete lack of screening pigment granules in both pigment and retinular cells C. consobrinus possess an unusually prominent dorsal rim area (DRA) with very large modified, non-twisting rhabdoms that are very likely to be polarization sensitive. However, I could not find evidence for the use of a polarization compass in this species. The results of experiments in which I occluded the DRA or the rest of the compound eye indicate that the DRA may mediate canopy orientation. I discuss C. consobrinus activity patterns, navigational mechanisms, compound eye adaptations and their recruitment strategy in the light of their association with foraging trees, the navigational information content of their environment and possible reasons for the particular temporal niche in which these ants are active

Distinct roles of the RasGAP family proteins in C. elegans associative learning and memory

The Ras GTPase activating proteins (RasGAPs) are regulators of the conserved Ras/MAPK pathway. Various roles of some of the RasGAPs in learning and memory have been reported in different model systems, yet, there is no comprehensive study to characterize all gap genes in any organism. Here, using reverse genetics and neurobehavioural tests, we studied the role of all known genes of the rasgap family in C. elegans in associative learning and memory. We demonstrated that their proteins are implicated in different parts of the learning and memory processes. We show that gap-1 contribute redundantly with gap-3 to the chemosensation of volatile compounds, gap-1 plays a major role in associative learning, while gap-2 and gap-3 are predominantly required for short- and long-term associative memory. Our results also suggest that the C. elegans Ras orthologue let-60 is involved in multiple processes during learning and memory. Thus, we show that the different classes of RasGAP proteins are all involved in cognitive function and their complex interplay ensures the proper formation and storage of novel information in C. elegans

Kinase-activating and kinase-impaired cardio-facio-cutaneous syndrome alleles have activity during zebrafish development and are sensitive to small molecule inhibitors

The Ras/MAPK pathway is critical for human development and plays a central role in the formation and progression of most cancers. Children born with germ-line mutations in BRAF, MEK1 or MEK2 develop cardio-facio-cutaneous (CFC) syndrome, an autosomal dominant syndrome characterized by a distinctive facial appearance, heart defects, skin and hair abnormalities and mental retardation. CFC syndrome mutations in BRAF promote both kinase-activating and kinase-impaired variants. CFC syndrome has a progressive phenotype, and the availability of clinically active inhibitors of the MAPK pathway prompts the important question as to whether such inhibitors might be therapeutically effective in the treatment of CFC syndrome. To study the developmental effects of CFC mutant alleles in vivo, we have expressed a panel of 28 BRAF and MEK alleles in zebrafish embryos to assess the function of human disease alleles and available chemical inhibitors of this pathway. We find that both kinase-activating and kinase-impaired CFC mutant alleles promote the equivalent developmental outcome when expressed during early development and that treatment of CFC-zebrafish embryos with inhibitors of the FGF-MAPK pathway can restore normal early development. Importantly, we find a developmental window in which treatment with a MEK inhibitor can restore the normal early development of the embryo, without the additional, unwanted developmental effects of the drug

MiR-223 Suppresses Cell Proliferation by Targeting IGF-1R

To study the roles of microRNA-223 (miR-223) in regulation of cell growth, we established a miR-223 over-expression model in HeLa cells infected with miR-223 by Lentivirus pLL3.7 system. We observed in this model that miR-223 significantly suppressed the proliferation, growth rate, colony formation of HeLa cells in vitro, and in vivo tumorigenicity or tumor formation in nude mice. To investigate the mechanisms involved, we scanned and examined the potential and putative target molecules of miR-223 by informatics, quantitative PCR and Western blot, and found that insulin-like growth factor-1 receptor (IGF-1R) was the functional target of miR-223 inhibition of cell proliferation. Targeting IGF-1R by miR-223 was not only seen in HeLa cells, but also in leukemia and hepatoma cells. The downstream pathway, Akt/mTOR/p70S6K, to which the signal was mediated by IGF-1R, was inhibited as well. The relative luciferase activity of the reporter containing wild-type 3′UTR(3′untranslated region) of IGF-1R was significantly suppressed, but the mutant not. Silence of IGF-1R expression by vector-based short hairpin RNA resulted in the similar inhibition with miR-223. Contrarily, rescued IGF-1R expression in the cells that over-expressed miR-223, reversed the inhibition caused by miR-223 via introducing IGF-1R cDNA that didn't contain the 3′UTR. Meanwhile, we also noted that miR-223 targeted Rasa1, but the downstream molecules mediated by Rasa1 was neither targeted nor regulated. Therefore we believed that IGF-1R was the functional target for miR-223 suppression of cell proliferation and its downstream PI3K/Akt/mTOR/p70S6K pathway suppressed by miR-223 was by targeting IGF-1R

SOS1 Mutations in Noonan Syndrome: Molecular Spectrum, Structural Insights on Pathogenic Effects, and Genotype–Phenotype Correlations

Noonan syndrome (NS) is among the most common nonchromosomal disorders affecting development and growth. NS is caused by aberrant RAS-MAPK signaling and is genetically heterogeneous, which explains, in part, the marked clinical variability documented for this Mendelian trait. Recently, we and others identified SOS1 as a major gene underlying NS. Here, we explored further the spectrum of SOS1 mutations and their associated phenotypic features. Mutation scanning of the entire SOS1 coding sequence allowed the identification of 33 different variants deemed to be of pathological significance, including 16 novel missense changes and in-frame indels. Various mutation clusters destabilizing or altering orientation of regions of the protein predicted to contribute structurally to the maintenance of autoinhibition were identified. Two previously unappreciated clusters predicted to enhance SOS1's recruitment to the plasma membrane, thus promoting a spatial reorientation of domains contributing to inhibition, were also recognized. Genotype–phenotype analysis confirmed our previous observations, establishing a high frequency of ectodermal anomalies and a low prevalence of cognitive impairment and reduced growth. Finally, mutation analysis performed on cohorts of individuals with nonsyndromic pulmonic stenosis, atrial septal defects, and ventricular septal defects excluded a major contribution of germline SOS1 lesions to the isolated occurrence of these cardiac anomalies. Hum Mutat 32:760–772, 2011. © 2011 Wiley-Liss, Inc

Whole-Genome Sequencing of a Single Proband Together with Linkage Analysis Identifies a Mendelian Disease Gene

Although more than 2,400 genes have been shown to contain variants that cause Mendelian disease, there are still several thousand such diseases yet to be molecularly defined. The ability of new whole-genome sequencing technologies to rapidly indentify most of the genetic variants in any given genome opens an exciting opportunity to identify these disease genes. Here we sequenced the whole genome of a single patient with the dominant Mendelian disease, metachondromatosis (OMIM 156250), and used partial linkage data from her small family to focus our search for the responsible variant. In the proband, we identified an 11 bp deletion in exon four of PTPN11, which alters frame, results in premature translation termination, and co-segregates with the phenotype. In a second metachondromatosis family, we confirmed our result by identifying a nonsense mutation in exon 4 of PTPN11 that also co-segregates with the phenotype. Sequencing PTPN11 exon 4 in 469 controls showed no such protein truncating variants, supporting the pathogenicity of these two mutations. This combination of a new technology and a classical genetic approach provides a powerful strategy to discover the genes responsible for unexplained Mendelian disorders