An Arctic Kelp Community in the Alaskan Beaufort Sea

The discovery of the "Boulder Patch", an area of cobbles and boulders with attached kelp and invertebrate life, is reported from Stefansson Sound, near Prudhoe Bay, Alaska. Geophysical surveys using side-scan sonar and low-frequency recording fathometers reveal that cobbles and boulders occur in patches of various sizes and densities. Despite a seasonal influx of sediments, the Boulder Patch is a nondepositional environment. Physical disruption of cobbles and boulders by deep draft ice is minimal due to offshore islands and shoals which restrict the passage of large ice floes into Stefansson Sound. The apparent absence of similar concentrations of rocks with attached biota along the Alaskan Beaufort Sea coast is explained by the scarcity of rocks in areas protected from ice abrasion and with no net sediment deposition. In Stefansson Sound, the rocks provide a substratum for a diverse assortment of invertebrates and several species of algae. Recolonization by the biota was minimal on twelve boulders denuded and then left undisturbed for a three-year period. Sedimentation and grazing activity appear to be the major factors inhibiting recolonization. Linear growth in the kelp, Laminaria solidungula, is greatest in winter and early spring when nutrients are available for new tissue growth. The plant draws on stored food reserves to complete over 90% of its annual linear growth during the nine months of darkness under a turbid ice canopy. These reserves are accumulated by photosynthetic activity during the preceding summer. The total carbon contribution made by kelp in Steffansson Sound under these conditions is about 146 million g/yr or 7 g/m²/yr. A small percentage of this carbon is consumed directly by herbivores, but its importance to other organisms in not known and is under investigation.Key words: kelp, Laminaria solidungula, Flaxman boulders, Beaufort Sea, Boulder Patch, productivity, recolonization, geophysical surveys, side-scan sonar, lag depositsMots clés: varech, Laminaria solidungula, grosses pierres Flaxman, mer de Beaufort, Boulder Patch, productivité, recolonisation, levées géophysiques, sonar à balayage latéral, accumulations de pierres par déflatio

Praxis Origins

The co-founders of the writing center studies journal Praxis look back on the origins of the journal, the role it played in their early careers as writing center administrators, and the way they wanted it to shape theory/practice in the field. Today, Praxis continues to evolve in response to the vision its editors bring and the changes they see in our disciplinary landscape

Writing Centers Feel the Crunch

Writing centers are feeling the effects of budget reductions across higher education nationwide. Like other student services that don’t offer credits or produce revenue, writing centers are particularly vulnerable to budget cuts. Community colleges, four-year colleges, and universities across the country are asking writing centers to make hard choices–choices that will affect consultant hiring, pay, and benefits as well as hours of operation, services, technological resources, and administration

Training on the Cutting Edge

Writing center consultants are leading busier and busier lives. As writing centers become standard fixtures in schools and communities, consultants are expected to enact educational, legislative and corporate change. However, while the demands on us are increasing, so are the tools we have at our disposal. Today’s writing center consultant is presented with a smorgasbord of training alternatives both within our own centers and online. Tried and true training approaches are still with us–classes, workshops, staff meetings, role-playing, observations, and mentoring–but they are increasingly supplemented by these new possibilities

Mutation analysis of 18 nephronophthisis associated ciliopathy disease genes using a DNA pooling and next generation sequencing strategy

Background Nephronophthisis associated ciliopathies (NPHP-AC) comprise a group of autosomal recessive cystic kidney diseases that includes nephronophthisis (NPHP), Senior-Loken syndrome (SLS), Joubert syndrome (JBTS), and Meckel-Gruber syndrome (MKS). To date, causative mutations in NPHP-AC have been described for 18 different genes, rendering mutation analysis tedious and expensive. To overcome the broad genetic locus heterogeneity, a strategy of DNA pooling with consecutive massively parallel resequencing (MPR) was devised.Methods In 120 patients with severe NPHP-AC phenotypes, five pools of genomic DNA with 24 patients each were prepared which were used as templates in order to PCR amplify all 376 exons of 18 NPHP-AC genes (NPHP1, INVS, NPHP3, NPHP4, IQCB1, CEP290, GLIS2, RPGRIP1L, NEK8, TMEM67, INPP5E, TMEM216, AHI1, ARL13B, CC2D2A, TTC21B, MKS1, and XPNPEP3). PCR products were then subjected to MPR on an Illumina Genome-Analyser and mutations were subsequently assigned to their respective mutation carrier via CEL I endonuclease based heteroduplex screening and confirmed by Sanger sequencing.Results For proof of principle, DNA from patients with known mutations was used and detection of 22 out of 24 different alleles (92% sensitivity) was demonstrated. MPR led to the molecular diagnosis in 30/120 patients (25%) and 54 pathogenic mutations (27 novel) were identified in seven different NPHP-AC genes. Additionally, in 24 patients only single heterozygous variants of unknown significance were found.Conclusions The combined approach of DNA pooling followed by MPR strongly facilitates mutation analysis in broadly heterogeneous single gene disorders. The lack of mutations in 75% of patients in this cohort indicates further extensive heterogeneity in NPHP-AC

Evaluating the Impact of Ethics Instruction on Student Awareness

Engineers must frequently make decisions during their careers without understanding or knowing the full set of consequences. These decisions can have unintended or harmful results. Therefore, it is imperative that engineers consider the ethical dimensions of their decisions while working to satisfy their employer’s interests even if these decisions conflict with their organization’s objectives or their own goals. Engineers have a responsibility to uphold a level of ethical standards that produces trust in not only their organization but also in their profession. Students entering the workforce must reflect the same level of ethical standards expected of their profession. Therefore, it is crucial to educate students on the importance of ethics and its impact on their future careers. This research examined the impact of ethics training in an upper-level engineering course consisting of 156 students. Students were presented with several scenarios that required them to make ethical judgments in the role of an engineer. A questionnaire, which evaluated the degree of ethical behavior of the students, was distributed at the start of the study. The same questionnaire was administered to the students after attending an educational session on ethics and ethical considerations in the engineering workplace. The responses were analyzed using the Chi-square test of independence and Wilcoxon signed-rank test to assess if ethics training had a significant impact on the ethical perspectives of the engineering students