The Effects of Aluminum Ion Exposure on Planarian Photophobic Response to Different Wavelengths of Light

Aluminum exposure has been linked to the development of neurological diseases (Kim et al., 2021). It has increased in quantity in the environment due to industrial activity in producing personal care products and fast food (Tietz et al., 2019). The freshwater invertebrate planarian flatworm Giardia dorotocephala (G. dorotocephala) serves as a model organism. Humans and planarians both express the ion channel transient receptor potential ankyrin 1 (TRPA1), which is responsible for thermotaxis, locomotive response to heat, and pain reception (Arenas et al., 2017). Aluminum exposure can exert ion channel-related toxicity via the TRPA1 protein. It has been found that planarian TRPA1 activates when exposed to light. The planarians have a photophobic reaction to light sources, meaning that when exposed to a light source they will instinctually swim away and towards the darkest area they can reach. This experiment addresses the question of what effect aluminum has on planarian photophobic behavior. We hypothesize that aluminum ion exposure increases photophobic behavior in planarians. The study was split into different parts that built off each other. First, planarians were exposed to various concentrations to determine their aluminum to reference dosage. It was determined that 300 mg/L aluminum was the highest dosage without acute behavioral toxicity. Next, we observed their reaction to different wavelengths of light to observe natural photophobic behavior in G. dorotocephala. The results suggest that all light sources garnered a photophobic response, while the no light control did not. The next experiment co-exposed the planarians to 300 mg/L aluminum and different wavelengths of light. It was found that white exposure did not elicit photophobic behavior, while UV light did cause photophobia, though this was dependent on the duration of aluminum exposure. To observe the planarians\u27 behavior to light when TRPA is modulated, they were exposed to HC-030031 dissolved in DMSO and DMSO alone. For both white and UV light, there was a steady decrease in their photophobic behavior. Taken together these results suggest that aluminum does not amplify their photophobic behavior. We suggest aluminum may instead inhibit planarian motility

PENGARUH DEBT DEFAULT DAN FINANCIAL DISTRESS TERHADAP OPINI AUDIT GOING CONCERN (Studi Empiris Pada Perusahaan Manufaktur Yang Terdaftar di Bursa Efek Indonesia (BEI) Tahun 2009-2013)

ABSTRAK Opini audit going concern yang diterima oleh sebuah perusahaan menunjukkan adanya kondisi dan peristiwa yang menimbulkan keraguan auditor akan kelangsungan hidup perusahaan. Opini audit going concern dapat digunakan sebagai peringatan awal bagi para pengguna laporan keuangan guna menghindari kesalahan dalam pembuatan keputusan. Beberapa penelitian mengenai faktorfaktor yang mempengaruhi terhadap opini audit going concern telah dilakukan. Namun, hasil penelitian tersebut masih menunjukkan ketidakkonsistenan. Penelitian ini bertujuan menguji kembali faktor-faktor yang berpengaruh terhadap opini audit going concern. Faktor-faktor yang diuji dalam penelitian ini lebih memfokuskan pada faktor debt default dan financial distress. Penelitian ini bertujuan untuk mengetahui besarnya pengaruh debt default dan financial distress terhadap opini audit going concern. Penelitian ini menggunakan perusahaan manufaktur yang terdaftar di Bursa Efek Indonesia periode 2009-2013 sebagai sampel penelitian. Berdasarkan hasil purposive sampling diperoleh 13 perusahaan manufaktur yang memenuhi kriteria sampel. Pengujian hipotesis dalam penelitian ini dilakukan dengan menggunakan analisis regresi logistik. Hasil pengujian hipotesis secara parsial menunjukan bahwa debt default berpengaruh signifikan terhadap opini audit going concern. Sedangkan financial distress tidak berpengaruh signifikan terhadap opini audit going concern, namun dengan arah koefisien yang negatif artinya semakin kecil nilai Zscorenya maka semakin besar terhadap penerimaan opini audit going concern. Berdasarkan hasil pengujian hipotesis secara simultan menunjukan bahwa debt default dan financial distress secara bersama-sama berpengaruh signifikan terhadap opini audit going concern. Kata kunci : Debt Default, Financial Distress, Opini Audit Going Concern

Pengaruh dimensi komitmen organisasi terhadap perilaku kerja proaktif pegawai pada Kantor Sekretariat Daerah Kota Palangka Raya

Penelitian ini bertujuan untuk memberikan penjelasan secara empiris tentang Dimensi Komitmen Organisasi terhadap Perilaku Kerja Proaktif Pegawai Kantor Sekretariat Daerah Kota Palangka Raya. Metode penelitian yang digunakan adalah kuantitatif dengan menggunakan pendekatan Partial Least Square (PLS), Sofware yang digunakan versi 3.2.8. Unit analisa penelitian ini adalah para pegawai yang berjumlah 112 orang. Hasil penelitian menunjukkan bahwa: a) Komitmen Afektif memiliki pengaruh positif signifikan terhadap Perilaku Kerja Proaktif Pegawai, b) Komitmen Normatif memiliki pengaruh positif signifikan terhadap Perilaku Kerja Proaktif Pegawai c) Komitmen Berkelanjutan memiliki pengaruh positif signifikan terhadap Perilaku Kerja Proaktif Pegawa

IMPROVING STUDENTS’ ABILITY IN USING PRESENT PERFECT CONTINUOUS TENSE THROUGH CONTEXTUAL TEACHING AND LEARNING

AbstractThis study aims to determine whether students’ abilities in using present perfect continuous tense can be improved through contextual teaching and learning and to explain the implementation of contextual teaching and learning in teaching present perfect continuous tense sentences to tenth grade students of Social Science at Sekolah Kristen AbdiWacana Pontianak. This research is based on a preliminary study which shows that the students still have lack of understanding of grammar patterns, especially in present perfect continuous tense sentences.This study implemented Classroom Action Research applied to address students’ problem in understanding and using present perfect continuous tense sentences. This study follows the basic pattern of Kurt Lewin and it is carried out in two cycles. The subjects in this study were students of class X IPS in SMA Kristen AbdiWacana Pontianak. The techniques used in collecting data were observation notes, interviews, questionnaires and tests. The result of this study indicates that the implementation of contextual teaching and learning was declared successful according to the achievement of criteria of success. The first criterion is that majority of students can reach a score ≥70, the second criterion is that the students were more active in learning activities.  Key Words: Classroom Action Research, Contextual Teaching and Learning, Present Perfect Continuous Tens