Primary neurons that express the L2/HNK-1 carbohydrate during early development in the zebrafish

In zebrafish, many nerve pathways in both the CNS and periphery are pioneered by a small and relatively simple set of ‘primary’ neurons that arise in the early embryo. We now have used monoclonal antibodies to show that, as they develop, primary neurons of several functional classes express on their surfaces the L2/HNK-1 tetrasaccharide that is associated with a variety of cell surface adhesion molecules. We have studied the early labeling patterns of these neurons, as well as some non-neural cells, and found that the time of onset and intensity of immunolabeling vary specifically according to cell type. The first neuronal expression is by Rohon-Beard and trigeminal ganglion neurons, both of which are primary sensory neurons that mediate touch sensitivity. These cells express the epitope very strongly on their growth cones and axons, permitting study of their development unobscured by labeling in other cells. Both types initiate axogenesis at the same early time, and appear to be the first neurons in the embryo to do so. Their peripheral neurites display similar branching patterns and have similar distinctive growth cone morphologies. Their central axons grow at the same rate along the same longitudinal fiber pathway, but in opposite directions, and where they meet they appear to fasciculate with one another. The similarities suggest that Rohon-Beard and trigeminal ganglion neurons, despite their different positions, share a common program of early development. Immunolabeling is also specifically present on a region of the brain surface where the newly arriving trigeminal sensory axons will enter the brain. Further, the trigeminal expression of the antigen persists in growth cones during the time that they contact an individually identified central target neuron, the Mauthner cell, which also expresses the epitope. These findings provide descriptive evidence for possible roles of L2/HNK-1 immunoreactive molecules in axonal growth and synaptogenesis

Myc Oncogene-Induced Genomic Instability: DNA Palindromes in Bursal Lymphomagenesis

Genetic instability plays a key role in the formation of naturally occurring cancer. The formation of long DNA palindromes is a rate-limiting step in gene amplification, a common form of tumor-associated genetic instability. Genome-wide analysis of palindrome formation (GAPF) has detected both extensive palindrome formation and gene amplification, beginning early in tumorigenesis, in an experimental Myc-induced model tumor system in the chicken bursa of Fabricius. We determined that GAPF-detected palindromes are abundant and distributed nonrandomly throughout the genome of bursal lymphoma cells, frequently at preexisting short inverted repeats. By combining GAPF with chromatin immunoprecipitation (ChIP), we found a significant association between occupancy of gene-proximal Myc binding sites and the formation of palindromes. Numbers of palindromic loci correlate with increases in both levels of Myc over-expression and ChIP-detected occupancy of Myc binding sites in bursal cells. However, clonal analysis of chick DF-1 fibroblasts suggests that palindrome formation is a stochastic process occurring in individual cells at a small number of loci relative to much larger numbers of susceptible loci in the cell population and that the induction of palindromes is not involved in Myc-induced acute fibroblast transformation. GAPF-detected palindromes at the highly oncogenic bic/miR-155 locus in all of our preneoplastic and neoplastic bursal samples, but not in DNA from normal and other transformed cell types. This finding indicates very strong selection during bursal lymphomagenesis. Therefore, in addition to providing a platform for gene copy number change, palindromes may alter microRNA genes in a fashion that can contribute to cancer development

Addressing Teacher Shortages in the COVID-19 Landscape: Viewing Teacher Candidates as Assets

COVID-19 continues to impose dire consequences on all sectors of our public education system. Many students, particularly those from vulnerable populations, are receiving reduced amounts of direct instruction and are experiencing significant losses in learning. At the same time, educator preparation programs (EPPs) are struggling to ensure that teacher candidates have ample opportunities to apply their newly acquired pedagogical skills in high quality clinical placements. In this article we describe and provide exemplars as to how teacher candidates can serve as assets to school districts as they complete their field placements. We also offer specific strategies and practices for EPPs and school districts to maximize the productive and efficient integration of teacher candidates in both virtual and in-person environments

CDK4 regulation by TNFR1 and JNK is required for NF-κB–mediated epidermal growth control

Nuclear factor κB (NF-κB) mediates homeostatic growth inhibition in the epidermis, and a loss of NF-κB function promotes proliferation and oncogenesis. To identify mechanisms responsible for these effects, we impaired NF-κB action in the epidermis by three different genetic approaches, including conditional NF-κB blockade. In each case, epidermal hyperplasia was accompanied by an increase in both protein levels and tissue distribution of the G1 cell cycle kinase, CDK4. CDK4 up-regulation required intact TNFR1 and c-Jun NH2-terminal kinase (JNK) function. Cdk4 gene deletion concomitant with conditional NF-κB blockade demonstrated that CDK4 is required for growth deregulation. Therefore, epidermal homeostasis depends on antagonist regulation of CDK4 expression by NF-κB and TNFR1/JNK

Notes on Iowa Tardigrades

Five species of tardigrades, Macrobiotus areolatus, M. islandicus M. hufelandii, Milnesium tardigradum, and Hypsibius tuberculata are reported from lichens growing on Iowa trees. Factors influencing tardigrade distribution are discussed, especially with reference to the lichen species represented in the samples, and the tree substrate. Hypsibius tuberculata was found to be most abundant about 2 meters above ground level, and to become less abundant below, while the other four species were found to be most abundant near the ground and decline steadily with increasing height. No clear evidence of preference of northern, southern, eastern, or western exposures was found

Pengantar Akuntansi Buku 1 -7/E.

PENGANTAR AKUNTANSI BUKU 1 -7/E. Materi Buku Pengantar Akuntansi Edisi 7 ini merupakan salah satu buku teks terbaik yang membahas berbagai konsep dasar akuntansi keuangan, yang dimulai dari siklus akuntansi untuk perusahaan jasa, siklus akuntansi untuk perusahaan dagang, dan perlakuan akuntansi untuk akun-akun utama perusahaan seperti kas, piutang, kewajiban, investasi, dan lain-lain. Buku ini dilengkapi dengan contoh dan kasus perusahaan nyata yang ditampilkan dalam Kotak Wawasan Etika, Wawasan e-Business, dan Wawasan Internasional. Laporan keuangan dan perusahaan terkemuka, yaitu PepsiCo dan Coca-Cola Company dilampirkan pada bagian akhir untuk memberikan gambaran kepada pembaca mengenai hasil akhir proses akuntansi yang dibahas. Selain itu, latihan dan soal yang beragam akan membantu para pembaca untuk semakin memahami konsep-konsep akuntansi yang dijelaskan. Buku ini ditujukan bagi mahasiswa yang mengambil mata kuliah Pengantar Akuntansi maupun bagi siapa saja yang ingin mengenal dan bermaksud mendapatkan pemahaman dasar akuntansi. Daftar Isi Bab 1 Penerapan Akuntansi Bab 2 Proses Pencatatan Bab 3 Penyesuaian Akun Bab 4 Penyelesaian Siklus Akuntansi Bab 5 Akuntansi untuk Perusahaan Dagang Bab 6 Persediaan Bab 7 Sistem Informasi Akuntansi Bab 8 Pengendalian Internal dan Kas Bab 9 Akuntansi untuk Piutang Bab 10 Aset Tetap, Sumber Daya Alam, dan Aset Tidak Berwujud