Conference and Collaboration: Using Writing Center in High School English Composition Instruction

I often ask aspiring secondary English teachers in my methods courses what they can tell me about writing instruction. They almost always identify a number of essential best practices: careful assignment guidelines that describe rationale, product, and process; clear student-friendly criteria; models students can relate to; specific feedback that is diagnostic in nature; and opportunities for revision. I then ask them to create a chronology of those practices, blocking out instructional days that correspond to those activities. Most of them are surprised to learn that all of these are either prewriting or post-first-draft strategies. When I ask them to examine the middle portion of their instructional period, they discover that the actual drafting stage is often absent of teacher intervention. Teaching while students are actually drafting–what we might call real-time instruction as opposed to pre-writing or teaching after the fact–is relatively rare and for many an awkward business that seems to defy the deliberate steps that characterize other phases of the process. And while many high school teachers rely on the individual conference as a critical aspect of process, most see this step as a post-draft activity not as something that happens simultaneously with the creation of text. What is even more remarkable is that so few refer to composition instruction that occurs while writers are drafting work in a lab equipped with computers. However, once the writing center model is introduced, opportunities for meaningful conference and collaboration increase dramatically.University Writing Cente

Neoblast Specialization in Regeneration of the Planarian Schmidtea mediterranea

Planarians can regenerate any missing body part in a process requiring dividing cells called neoblasts. Historically, neoblasts have largely been considered a homogeneous stem cell population. Most studies, however, analyzed neoblasts at the population rather than the single-cell level, leaving the degree of heterogeneity in this population unresolved. We combined RNA sequencing of neoblasts from wounded planarians with expression screening and identified 33 transcription factors transcribed in specific differentiated cells and in small fractions of neoblasts during regeneration. Many neoblast subsets expressing distinct tissue-associated transcription factors were present, suggesting candidate specification into many lineages. Consistent with this possibility, klf, pax3/7, and FoxA were required for the differentiation of cintillo-expressing sensory neurons, dopamine-β-hydroxylase-expressing neurons, and the pharynx, respectively. Together, these results suggest that specification of cell fate for most-to-all regenerative lineages occurs within neoblasts, with regenerative cells of blastemas being generated from a highly heterogeneous collection of lineage-specified neoblasts.National Institutes of Health (U.S.) (R01GM080639)National Science Foundation (U.S.). Graduate Research Fellowship Program (Grant 1122374

THE IMPORTANCE OF BEING MEAN

Many historical loci can be obtained through approaches that differ from classic methods built on their own pure description as loci. Aim of this work is to show how various algebraic curves can be obtained as the locus for particular midpoints, and how the consideration of the latter can give rise to a succession of homotheties, namely, contractions or dilations, of the original curve. What is important to underline is that points generating a locus possess the particular property of being midpoints of other pairs of points, or segments, stemming from a particular configurations of points and lines. This is illustrated here, by various examples

Development of novel methods for the determination of antimicrobial capabilities of photocatalytic titania coatings

Pathogenic and food spoilage organisms can survive on surfaces for extended periods of time and must be removed or inactivated to avoid product spoilage and disease. Current interventions include chemical and physical cleaning protocols, which can be costly and environmentally unsustainable. Coating surfaces with photocatalytic titanium dioxide may represent a solution to these issues, due to its stability, sustainability, low cost and significant self-cleaning and antimicrobial properties. However, only UV can activate the photocatalyst, making the technology impractical for many desired applications. By doping the titania with other materials, it is possible to achieve activation using visible light. The focus of this thesis was to produce visible light-activated photocatalytic coatings and assess their antimicrobial efficacy. Furthermore, the current tests used to assess antimicrobial efficacy are complex, time-consuming and unattractive for non-specialists. Therefore, this work also aimed to develop simple, rapid tests for the antimicrobial potential of photocatalytic coatings. Titanium dioxide films doped with molybdenum or niobium at a range of concentrations were produced on stainless steel and glass substrates using magnetron sputtering techniques, annealed at a range of times and temperatures and characterised via EDX, SEM, XRD and optical profiling. The photocatalytic activity of the films was measured via the degradation of methylene blue while the photocatalytic-antimicrobial properties were determined using an adaptation of the BS ISO 27447:2009 test. It was found that Mo-TiO2 had improved visible light activity and photocatalytic-antimicrobial properties; antimicrobial activity was also present in the absence of irradiation, while Nb-TiO2 did not show improved activity compared to undoped TiO2. The substrate greatly affected the antimicrobial activity of Mo-TiO2 and this was ascribed to differences in roughness and surface area; substrates with lower surfaces areas consistently had reduced antimicrobial activity. Two existing methods were identified in the literature and redeveloped as assays for photocatalytic-antimicrobial efficacy. The first method was based on real time in situ light absorbance of bacteria in suspension using inexpensive spectrophotometric equipment. This method showed promise, approximating the viability dynamics of a planktonic suspension well. However, assessment of decreases in viability could not be made. The second method was based on the time taken to detect changes in the colour of resazurin dye to indicate the viability of bacteria after a period of irradiation. The time to detect a colour change was inversely proportional to the viable population size and thus represents a rapid alternative for enumeration of viable cells following photocatalytic treatment. Furthermore, the test was stratified into three tiers of sensitivity and complexity and so can be used as a first-stage screening for putative photocatalytic-antimicrobial properties, or a fully quantitive enumeration technique. It is hoped that that this alternative test will enable non-specialists to further develop their photocatalytic coatings for antimicrobial use

Eye Absence Does Not Regulate Planarian Stem Cells during Eye Regeneration

Dividing cells called neoblasts contain pluripotent stem cells and drive planarian flatworm regeneration from diverse injuries. A long-standing question is whether neoblasts directly sense and respond to the identity of missing tissues during regeneration. We used the eye to investigate this question. Surprisingly, eye removal was neither sufficient nor necessary for neoblasts to increase eye progenitor production. Neoblasts normally increase eye progenitor production following decapitation, facilitating regeneration. Eye removal alone, however, did not induce this response. Eye regeneration following eye-specific resection resulted from homeostatic rates of eye progenitor production and less cell death in the regenerating eye. Conversely, large head injuries that left eyes intact increased eye progenitor production. Large injuries also non-specifically increased progenitor production for multiple uninjured tissues. We propose a model for eye regeneration in which eye tissue production by planarian stem cells is not directly regulated by the absence of the eye itself. Keywords: planarian; regeneration; stem cell; eye; tissue turnover; target blind; progenitor; neoblastNational Institutes of Health (U.S.) (Grant R01GM080639

Landmarks in Existing Tissue at Wounds Are Utilized to Generate Pattern in Regenerating Tissue

Regeneration in many organisms involves the formation of a blastema, which differentiates and organizes into the appropriate missing tissues. How blastema pattern is generated and integrated with pre-existing tissues is a central question in the field of regeneration. Planarians are free-living flatworms capable of rapidly regenerating from small body fragments [1]. A cell cluster at the anterior tip of planarian head blastemas (the anterior pole) is required for anterior-posterior (AP) and medial-lateral (ML) blastema patterning [2–4]. Transplantation of the head tip into tails induced host tissues to grow patterned head-like outgrowths containing a midline. Given the important patterning role of the anterior pole, understanding how it becomes localized during regeneration would help explain how wounds establish pattern in new tissue. Anterior pole progenitors were specified at the pre-existing midline of regenerating fragments, even when this location deviated from the ML median plane of the wound face. Anterior pole progenitors were specified broadly on the dorsal-ventral (DV) axis and subsequently formed a cluster at the DV boundary of the animal. We propose that three landmarks of pre-existing tissue at wounds set the location of anterior pole formation: a polarized AP axis, the pre-existing midline, and the dorsal-ventral median plane. Subsequently, blastema pattern is organized around the anterior pole. This process, utilizing positional information in existing tissue at unpredictably shaped wounds, can influence the patterning of new tissue in a manner that facilitates integration with pre-existing tissue in regeneration.National Institute of General Medical Sciences (U.S.) (Award T32GM007753)National Institutes of Health (U.S.) (Grant R01GM080639

Possible A2E Mutagenic Effects on RPE Mitochondrial DNA from Innovative RNA-Seq Bioinformatics Pipeline

Mitochondria are subject to continuous oxidative stress stimuli that, over time, can impair their genome and lead to several pathologies, like retinal degenerations. Our main purpose was the identification of mtDNA variants that might be induced by intense oxidative stress determined by N-retinylidene-N-retinylethanolamine (A2E), together with molecular pathways involving the genes carrying them, possibly linked to retinal degeneration. We performed a variant analysis comparison between transcriptome profiles of human retinal pigment epithelial (RPE) cells exposed to A2E and untreated ones, hypothesizing that it might act as a mutagenic compound towards mtDNA. To optimize analysis, we proposed an integrated approach that foresaw the complementary use of the most recent algorithms applied to mtDNA data, characterized by a mixed output coming from several tools and databases. An increased number of variants emerged following treatment. Variants mainly occurred within mtDNA coding sequences, corresponding with either the polypeptide-encoding genes or the RNA. Time-dependent impairments foresaw the involvement of all oxidative phosphorylation complexes, suggesting a serious damage to adenosine triphosphate (ATP) biosynthesis, that can result in cell death. The obtained results could be incorporated into clinical diagnostic settings, as they are hypothesized to modulate the phenotypic expression of mtDNA pathogenic variants, drastically improving the field of precision molecular medicine

Next generation semiconductor based sequencing of the donkey (Equus asinus) genome provided comparative sequence data against the horse genome and a few millions of single nucleotide polymorphisms

Few studies investigated the donkey (Equus asinus) at the whole genome level so far. Here, we sequenced the genome of two male donkeys using a next generation semiconductor based sequencing platform (the Ion Proton sequencer) and compared obtained sequence information with the available donkey draft genome (and its Illumina reads from which it was originated) and with the EquCab2.0 assembly of the horse genome. Moreover, the Ion Torrent Personal Genome Analyzer was used to sequence reduced representation libraries (RRL) obtained from a DNA pool including donkeys of different breeds (Grigio Siciliano, Ragusano and Martina Franca). The number of next generation sequencing reads aligned with the EquCab2.0 horse genome was larger than those aligned with the draft donkey genome. This was due to the larger N50 for contigs and scaffolds of the horse genome. Nucleotide divergence between E. caballus and E. asinus was estimated to be similar to 0.52-0.57%. Regions with low nucleotide divergence were identified in several autosomal chromosomes and in the whole chromosome X. These regions might be evolutionally important in equids. Comparing Y-chromosome regions we identified variants that could be useful to track donkey paternal lineages. Moreover, about 4.8 million of single nucleotide polymorphisms (SNPs) in the donkey genome were identified and annotated combining sequencing data from Ion Proton (whole genome sequencing) and Ion Torrent (RRL) runs with Illumina reads. A higher density of SNPs was present in regions homologous to horse chromosome 12, in which several studies reported a high frequency of copy number variants. The SNPs we identified constitute a first resource useful to describe variability at the population genomic level in E. asinus and to establish monitoring systems for the conservation of donkey genetic resources