Incidental motor sequence learning: Investigations into its cognitive basis and the effects of neurological impairment and treatment

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.To survive in a complex changing environment humans frequently need to adapt their behaviour incidentally from normal interactions in the environment without any specific intention to learn. Whilst there is a considerable body of research into incidental learning of sequential information there is still fundamental debate regarding its cognitive basis, the associated neural mechanisms and the way in which it is affected by neurological disease. These issues were explored, in normal participants and neurological patients, using manipulations of the Serial Reaction Task [SRT] in which participants gradually learn a stimulus sequence (usually screen locations) after responding to each item by pressing corresponding response buttons. The first two experiments (chapter 3) demonstrate that the specific metric used to quantify learning and the occurrence of highly salient repeat locations may inflate estimates of learning in tasks with increased motor demands. The next three experiments (chapter 4) examine whether a secondary (not directly behaviourally relevant) information source during the SRT facilitates chunking in memory and overall learning. In a spatial SRT task (specified by horizontal location), additional spatial information (vertical location) enhanced learning but a secondary perceptual property (colour) produced a cost. However, in a perceptual SRT a secondary perceptual property (colour) had no effect. The next study demonstrates that impairments of incidental learning in Parkinson’s disease are partially reduced by administration of l-Dopa. Implications for models of striatal function and studies suggesting implicit learning is impaired by l-Dopa are discussed. Finally, the impact of Deep Brain Stimulation of the GPi is investigated in a population known to have only limited cognitive deficits relating to their illness (dystonia). Despite previous reports of impaired intentional learning in participants with a high genetic risk of Dystonia, there was no evidence for any impairment before or after stimulation. Implications across studies and future research directions are also discussed

Wear Performance Of Alumina Based Cutting Tool When Machined With AISI 1045 Carbon Steel

Latest developments in the manufacturing industry aim to produce high quality products with reduced time and cost. Automated and flexible manufacturing systems such as the computerized numerical control (CNC) machines are employed due to the capable of minimizing the processing time while achieving high accuracy. Machining essentially will produce high cutting temperature that reduce tool life. Tool wear is a paramount factor in determining tool life. It affects surface quality and precision of dimensions of the workpiece. Therefore, ceramic cutting tools are widely used for machining hard materials such as cast irons, alloy steels and carbon steels. These materials are so hard that they possess wide range of hardness and high temperature resistance due to high hot hardness and very good chemical stability (Whitney, 1994). Alumina cutting tool is commonly used for machining hard materials in high speed. It is also suitable for dry machining for its uniqueness in mechanical and chemical properties, especially at high temperature, such as high wear resistance, relatively low chemical reactivity with steels, high hot hardness, chemical inertness and high abrasion resistance (Deng et al., 2012). However, it is still expected that there will be temperature rise that may result to molten metal to cause material deformation. Another type of alumina cutting tool; alumina with zirconia reinforcement is said to offer an improved properties from the alumina based. The two types of ceramic cutting tool are fabricated and machined using AISI 1045 carbon steel to evaluate and compare the performance of tool wear and surface roughness of the workpiece. Results shows that both alumina and alumina-zirconia is capable to be fabricated as cutting tools and solidly represent the round shape of cutting tool with adequate hardness. Cutting tool fabricated with alumina and zirconia powder exhibited better wear performance as compared to the cutting tool with alumina only. The alumina-zirconia based cutting tool recorded a maximum of 200s tool life as compared to 145s for alumina based cutting tool. Surface roughness when AISI 1045 is machined with both cutting tools exhibited almost similar characteristics. Maximum value is recorded at 3.16 μm when machining with alumina-zirconia cutting tool after 150s. Whereas, minimum surface roughness is recorded at 0.67 μm with the same cutting tool type; the alumina-zirconia based which is at 150s cutting time. Wear development of cutting tool demonstrated uniform wear land at the early stage of machining before gradually notching at the specific region of wear before attachment of built up edge along cutting edges. For alumina based tool, the wear mechanism is dominated by the obvious formation of built up edge and adhesive wear. Whereas for alumina-zirconia based cutting tool, wear mechanism is dominated by the minor formation of built up edge and small particles detachment at the cutting edge

Pengaruh Kinerja Lingkungan terhadap Nilai Perusahaan dan Kinerja Keuangan

The objective of this study is to examine the influence of enviromental performance to firm value with financial performance as intervening variable. This study takes sample from 31 companies in the Indonesian Stock Exchange, which were published in financial report from 2010-2011. The method of analysis of this research used multi regression and path analysis. The results of this study show that (1) enviromental performance had significant influence to financial performance, (2) enviromental performance had not significant influence to firm value, (3) financial performance had significant influence to firm value, (4) enviromental performance had significant influence on the financial performance of the firm's value through. Financial performance is an intervening variable in the relationship between environmental performance and the audit committee of the firm's value

Analisis Dampak Pemindahan Ibu Kota Negara (IKN) Terhadap Social Security

Di Indonesia, terdapat berbagai faktor yang menjadi pertimbangan perlunya dilakukan pemindahan Ibu Kota Negara. Antara lain faktor sosial, ekonomi, politik, budaya, pertahanan dan kemanan, hingga faktor bencana alam. Kesenjangan sosial ekonomi dan kependudukan merupakan salah satu faktor pendorong rencana pemindahan Ibu Kota Negara ndonesia. Pemindahan Ibu Kota Negara ke luar Jawa bertujuan untuk mengurangi beban ekologis kota Jakarta yang sudah sangat berat. Baik itu berupa kepadatan penduduk, kemacetan lalu lintas, polusi udara hingga kondisi air yang kurang baik. Pemindahan ibu kota bukanlah hal yang mudah karena ibu kota adalah kota utama dalam kegiatan sosial, ekonomi, dan politik sehingga kesalahan pemindahan berpotensi menimbulkan berbagai permasalahan. Penelitian ini dilakukan untuk mengetahui dampak pemindahan Ibu Kota Negara terhadap social security. Baik untuk masyarakat di daerah eks ibu kota maupun di daerah ibu kota baru. Penelitian dilakukan dengan metode kualitatif menggunakan pendekatan historis. Proses pengumpulan data dilakukan dengan mempelajari buku, jurnal, berita maupun bahan bacaan lainnya yang berhubungan dengan topik pemindahan Ibu Kota Negara untuk kemudian diklasifikan berdasarkan pokok bahasan masing-masing. Hasil penelitian menunjukkan bahwa pemindahan Ibu Kota Negara mampu menjadi solusi dalam menyelesaikan permasalahan yang terjadi sekaligus memberikan dampak positif terhadap social security bagi masyarakat baik di daerah eks Ibu Kota (DKI Jakarta) maupun untuk masyarakat di daerah Ibu Kota Negara baru (Kalimantan Timur)

ANALISIS KUALITAS SUMBER AIR BAKU PADA SUMUR BOR DI DEPOT AIR MINUM ISI ULANG (STUDI KASUS DEPOT AIR MINUM ISI ULANG (DAMIU) DI KABUPATEN SELUMA)

Telah dilakukan penelitian dengan judul Analisis Kualitas Sumber Air Baku Pada Sumur Bor Di Depot Air Minum Isi Ulang (Studi Kasus Depot Air Minum Isi Ulang (DAMIU) Di Kabupaten Seluma), adapun tujuan penelitian ini adalah untuk Mengidentifikasikan sumber air baku dari sumur bor yang digunakan oleh DAMIU di Kabupaten Seluma sesuai dengan PERMENKES RI Nomor 492/MENKES/PER/IV/2010, Mendeskripsikan bahan, peralatan, proses pengelolaan, dan perilaku sanitasi DAMIU di Kabupaten Seluma dan menganalisis Kualitatif Fisik dan Biologi Air Minum Isi Ulang di Kabupaten Seluma. Metode penelitian deskriptif kualitatif dan sampel sebanyak 6 sampel 4 DAMIU memenuhi syarat dan 2 DAMIU tidak memenuhi syarat

Reverse total shoulder arthroplasty—from the most to the least common complication

Reverse total shoulder arthroplasty (RTSA) has been reported to be associated with a complication rate that is four times that of conventional total shoulder arthroplasty. It is the purpose of this article to identify and understand the most common and most serious complications of RTSA and to review current methods of prevention and treatment. The current literature was reviewed to identify type and prevalence of reported complications and to identify risk factors, preventive measures as well as technical details for management strategies for complications of RTSA. The variable accuracy of reporting and the heterogeneity of methodology in the literature limited our study, however, a definitive ranking of most to least common complication emerged. The currently identified most common complication is scapular notching. The clinically most relevant complications are infection, instability and acromial fractures. Haematoma formation used to be very frequent but can be controlled, glenoid component loosening, however, is rare when compared with conventional total shoulder replacement. In conclusion, RTSA is associated with a high rate of complications. Their incidence and the results of their treatment are inconsistently reported. To document and then prevent complications, a standardised monitoring tool including clear definitions and assessment instructions appears necessar

Analisis Pengenaan Pajak Final dan Non Final pada Perusahaan Jasa Konstruksi di Bei

Penelitian ini dilakukan untuk mengetahui perbedaan antara pengenaan pajak final dan pajak non final. Penelitian ini menggunakan data laporan keuangan yang telah dipublikasi selama kurun waktu 2010-2014 (lima tahun). Metode statistik dalam penelitian ini menggunakan uji normalitas, uji homogenitas, uji ANOVA, dan Uji Independent t-Test. Berdasarkan hasil analisis statistik bahwa terdapat perbedaan yang signifikan antara pengenaan pajak final dan pajak non final dalam menentukan besarnya pajak yang terutang. Pengenaan pajak final lebih besar secara signifikan dibandingkan dengan pengenaan pajak non final. Bagi pemerintah, pengenaan pajak secara final dinilai sangat menguntungkan karena dapat menambah sumber penerimaan dalam keuangan negara. Namun, disisi lain bagi wajib dinilai sangat merugikan karena pengenaan pajak secara final tidak memperhatikan biaya-biaya yang dikeluarkan dalam memperoleh penghasilan tersebut

Pengaruh Iradiasi Gamma Pada Aktivitas Sitotoksik Daging Buah Mahkota Dewa (Phaleria Macrocarpa (Scheff) Boerl.)

Iradiasi gamma telah digunakanoleh industri obat herbal untuk pengawetan simplisia tanaman obat, tetapi pengaruh iradiasiterhadap khasiatnya belum diteliti. Tujuan penelitian adalah memperoleh dosis iradiasi optimaluntuk pengawetan simplisia daging buah mahkota dewa tanpa merusak khasiatnya. Telahdilakukan iradiasi gamma terhadap simplisia daging buah kering mahkota dewa pada variasidosis 0; 5; 7,5 ; 10; 15; 20 kGy. Cemaran mikroba diuji dengan metode yang mengacu padaSNI, yang menunjukkan bahwa dosis 5 kGy telah dapat membunuh seluruh mikroba. Masingmasingsampel dimaserasi dengan etanol, lalu ekstrak yang diperoleh difraksinasi dengankromatografi kolom, diperoleh 8 fraksi. Uji sitotoksisitas fraksi-fraksi terhadap sel leukemiaL1210 menunjukkan bahwa Fr.3 merupakan fraksi paling sitotoksik. Untuk menentukan dosisiradiasi optimal dalam menghambat pertumbuhan serta membunuh semua bakteri dankapang/khamir pada simplisia daging buah mahkota dewa tanpa menurunkan aktivitassitotoksik, dilakukan analisis kromatografi lapis tipis (KLT) dan kromatografi cair kinerja tinggi(KCKT) terhadap Fr.3. Hasil penelitian menunjukkan bahwa iradiasi dengan dosis > 5 kGy padasimplisia daging buah mahkota dewa dapat menghambat pertumbuhan dan membunuh semuabakteri serta kapang khamir yang ada tanpa menurunkan aktivitas sitotoksik ekstrak etanolsecara nyata terhadap sel leukemia L1210. Penurunan aktivitas sitotoksik ekstrak etanolterhadap sel leukemia L1210 secara nyata terjadi setelah iradiasi pada dosis > 10 kGy. Padadosis 10 kGy, aktivitas sitotoksik sudah terlihat menurun meskipun belum melampaui batassuatu fraksi dinyatakan tidak aktif dan hasil analisis profil kromatogram KLT menunjukkanbahwa Fr. 3 sedikitnya mengandung 10 komponen. Iradiasi sampai dengan dosis 20 kGymengakibatkan intensitas salah satu puncak mayor menurun, dan penurunannya sebandingdengan besarnya dosis. Dosis 5 sampai 10 kGy merupakan dosis optimum untuk tujuanpengawetan tanpa merusak aktivitas sitotoksiknya