917 research outputs found
Inhomogeneous metallic phase upon disordering a two dimensional Mott insulator
We find that isoelectronic disorder destroys the spectral gap in a
Mott-Hubbard insulator in 2D leading, most unexpectedly, to a new metallic
phase. This phase is spatially inhomogeneous with metallic behavior coexisting
with antiferromagnetic long range order. Even though the Mott gap in the pure
system is much larger than antiferromagnetic exchange, the spectral gap is
destroyed locally in regions where the disorder potential is high enough to
overcome the inter-electron repulsion thereby generating puddles where charge
fluctuations are enhanced. With increasing disorder, these puddles expand and
concomitantly the states at the Fermi energy get extended leading to a metallic
phase. We discuss the implications of our results for experiments.Comment: (4 pages, 5 figures
Kontribusi Optimisme Terhadap Kebahagiaan Pada Karyawan
Kebahagiaan dalam kehidupan merupakan suatu hal yang menjadi harapan dalam kehidupan banyak individu, maka dalam mencapai kehidupan yang berbahagia tersebut, banyak individu yang mencapainya dengan cara bekerja. Sayangnya, di Indonesia masih banyak karyawan atau pekerja yang tidak bahagia dengan pekerjaannya. Berdasarkan latar belakang yang dicantumkan terdapat alasan karyawan diberhentikan dari pekerjaannya yaitu menghilangnya rasa optimis dari karyawan tersebut. Tujuan dari penelitian ini adalah untuk menguji kontribusi optimisme terhadap kebahagiaan pada karyawan. Penelitian ini menggunakan metode kuantitaif dengan menggunakan kuesioner yang terdiri dari dua alat ukur, yaitu skala kebahagiaan dan skala optimisme (LOT-R). Sampel dalam penelitian ini adalah karyawan tetap dan jabatan setara staff dan berjenis kelamin laki-laki ataupun wanita sebanyak 80 responden. Uji hipotesis dalam penelitian ini dilakukan dua tahap, yang pertama yaitu uji hubungan yang menunjukkan hasil bahwa optimisme memiliki hubungan yang sangat signifikan dengan kebahagiaan. Dan selanjutnya uji regresi yang menunjukkan hasil bahwa hipotesis diterima dengan nilai F sebesar 216,511 dan signifikasi sebesar 0,000 serta R Square sebesar 0,735. Artinya optimisme memiliki kontribusi yang sangat signifikan terhadap kebahagiaan pada karyawan dengan sumbangan relatif sebesar 73,5% dan sisanya 26,5% merupakan faktor lain diluar penelitian
Stroke Prediction from Hypertensive Retinopathy
Hypertensive Retinopathy (HR) is known as the damage to the eye which occurs due
to high blood pressure. This HR may lead to permanent vision lost hence timely
diagnosis and treatment of this disease is very important. Fundus image analysis is
used to diagnose HR and stroke prediction. There are four steps in the proposed
systems which are the Image Enhancement, Fourier Fractal Dimension, Logistic
Regression Classifier and Stroke Prediction Model. The proposed system consists of
method used to analyse retina blood vessels using Fourier Fractal Dimension to
extract the complexity of the retina blood vessels enhanced in different scales.
Logistic regression was used to model the classifier for stroke prediction. The
probability from 0 to 0.5 was classified as control case and the probability from 0.5
to 1 was classified as stroke case. From 20 images used in this project only 14
images was classified as the stroke case. The estimated percentage increase in the
odds of incident of stroke is calculated and categorised according to the Hypertensive
Retinopathy stages
Hubungan Antara Regulasi Emosi Dengan Problem Focused Coping Pada Taruna Tingkat III Akademi Kepolisian Semarang
Taruna Akademi Kepolisian adalah calon perwira pertama Polri yang akan menjadi penegak hukum di Indonesia. Adanya tuntutan dan kewajiban yang harus dijalani Taruna Akpol dapat menimbulkan stres, sehingga Taruna Akpol perlu melakukan coping stress dengan menggunakan problem focused copingdan menghindari perilaku yang dapat menyebabkan emosi negatif dengan melakukan regulasi emosi.Penelitian ini bertujuan untuk mengetahui hubungan antara regulasi emosi dengan problem focused coping pada Taruna. Subjek penelitian ini adalah Taruna tingkat III Akademi Kepolisian Semarang. Subjek penelitian berjumlah 181 Taruna dari 346 populasi jumlah Taruna tingkat III Akpol tahun ajaran 2013-2014. Teknik pengambilan sampel menggunakan simple random sampling. Pengumpulan data dengan menggunakan skala, yaitu skala problem focused coping (25 aitem valid α =0,885) dan skala regulasi emosi (26 aitem valid α=0,898).Analisis regresi sederhana menunjukkan hasil koefisien korelasi rxy= 0,860 dengan p=0,000 (p<0,05), artinya terdapat hubungan positif yang signifikan antara regulasi emosi dengan problem focused coping pada Taruna tingkat III Akademi Kepolisian Semarang.Hasil tersebut menunjukkan bahwa semakintinggi regulasi emosi, maka semakin tinggi problem focused coping yang dimiliki Taruna.Sebaliknya, apabila semakin rendah regulasi emosi maka problem focused copingTaruna terhadapsemakin rendah. Sumbangan efektifregulasi emosi dengan problem focused coping yaitu sebesar 73,9% sedangkan 26,1% berasal dari faktor-faktor lain yang tidak diungkap dalam penelitian ini yaitu sepertidukungan sosial, status sosial ekonomi, konsep diri, religiusitas dan kondisi stressor
Assessment of knowledge regarding prevention and treatment of Ebola virus among undergraduate medical students in Chennai, India: a questionnaire based study
Background: Ebola virus disease is a dreadful condition associated with high mortality rate threatening the entire world. Our study was aimed to assess the knowledge and to create awareness about Ebola among undergraduate medical students.Methods: A self-administered, pretested questionnaire with 30 questions focusing on the general information of virus, mode of transmission, clinical features and complications of the infection, diagnosis, treatment, preventive measures, and epidemiological features was given to the study participants. Scoring system was followed, and statistical analysis was done using Chi-square test and comparison between different sections by one-way analysis of variance.Results: Totally, 263 medical students participated in the study. Based on the percentile of scores obtained they were categorized into three groups, better knowledge (18-30), average knowledge (10-17), poor knowledge (0-9). On the whole 70% students had an average level of knowledge 25% students had better knowledge and 5% students had poor knowledge. Female students had better knowledge when compared to male students (p<0.0001). Similarly, second year students had better knowledge than interns and final year students (p<0.0001). Students had less knowledge regarding clinical features, epidemiological features and relatively poor knowledge regarding diagnosis and treatment. Comparatively, knowledge about mode of transmission, preventive measures and general information of virus were better.Conclusion: This study demonstrates apparent lack of knowledge regarding various aspects of Ebola and emphasis to conduct awareness programs to manage the dreadful consequences of the disease if rises
Electrostatic- and Parallel Magnetic Field- Tuned Two Dimensional Superconductor-Insulator Transitions
The 2D superconductor-insulator transition in disordered ultrathin amorphous
bismuth films has been tuned both by electrostatic electron doping using the
electric field effect and by the application of parallel magnetic fields.
Electrostatic doping was carried out in both zero and nonzero magnetic fields,
and magnetic tuning was conducted at multiple strengths of electrostatically
induced superconductivity. The transitions were analyzed using finite size
scaling with critical exponent products nu*z = 0.65-0.7. The parallel critical
magnetic field increased with electron transfer as (dn_c-dn)^0.33, where dn is
the electron transfer and dn_c is its critical value, and the critical
resistance decreased linearly with dn. However at lower temperatures, in the
insulating regime, the resistance became larger than expected from
extrapolation of its temperature dependence at higher temperatures, and scaling
failed. These observations imply that although the electrostatic- and parallel
magnetic field- tuned superconductor-insulator transitions would appear to
belong to the same universality class and to be delineated by a robust phase
boundary that can be crossed either by tuning electron density or magnetic
field, in the case of the field-tuned transition at the lowest temperatures,
some different type of physical behavior turns on in the insulating regime.Comment: About 11 pages, with 14 figures. To be submitted to Phys Rev
Recommended from our members
Predictability and prediction of persistent cool states of the Tropical Pacific Ocean
The Tropical Pacific Ocean displays persistently cool sea surface temperature (SST) anomalies that last several years to a decade, with either no El Niño events or a few weak El Niño events. These cause largescale droughts in the extratropics, including major North American droughts such as the 1930s Dust Bowl, and also modulate the global mean surface temperature. Here we show that two models with different levels of complexity— the Zebiak–Cane intermediate model and the Geophysical Fluid Dynamics Laboratory Coupled Model version 2.1— are able to produce such periods in a realistic manner. We then test the predictability of these periods in the Zebiak– Cane model using an ensemble of experiments with perturbed initial states. Our results show that in most cases the cool mean state is predictable. We then apply this method to make retrospective forecasts of shifts in the decadal mean state and to forecast the mean state of the Tropical Pacific Ocean for the upcoming decade. Our results suggest that the Pacific will undergo a shift to a warmer mean state after the 2015–2016 El Niño. This could imply the cessation of the drier than normal conditions that have generally afflicted southwest North America since the 1997–1998 El Niño, as well as the twenty-first-century pause in global warming. Implications for our understanding of the origins of such persistent cool states and the possibility of improving predictions of large-scale droughts are discussed
Automated Protein Subfamily Identification and Classification
Function prediction by homology is widely used to provide preliminary functional annotations for genes for which experimental evidence of function is unavailable or limited. This approach has been shown to be prone to systematic error, including percolation of annotation errors through sequence databases. Phylogenomic analysis avoids these errors in function prediction but has been difficult to automate for high-throughput application. To address this limitation, we present a computationally efficient pipeline for phylogenomic classification of proteins. This pipeline uses the SCI-PHY (Subfamily Classification in Phylogenomics) algorithm for automatic subfamily identification, followed by subfamily hidden Markov model (HMM) construction. A simple and computationally efficient scoring scheme using family and subfamily HMMs enables classification of novel sequences to protein families and subfamilies. Sequences representing entirely novel subfamilies are differentiated from those that can be classified to subfamilies in the input training set using logistic regression. Subfamily HMM parameters are estimated using an information-sharing protocol, enabling subfamilies containing even a single sequence to benefit from conservation patterns defining the family as a whole or in related subfamilies. SCI-PHY subfamilies correspond closely to functional subtypes defined by experts and to conserved clades found by phylogenetic analysis. Extensive comparisons of subfamily and family HMM performances show that subfamily HMMs dramatically improve the separation between homologous and non-homologous proteins in sequence database searches. Subfamily HMMs also provide extremely high specificity of classification and can be used to predict entirely novel subtypes. The SCI-PHY Web server at http://phylogenomics.berkeley.edu/SCI-PHY/ allows users to upload a multiple sequence alignment for subfamily identification and subfamily HMM construction. Biologists wishing to provide their own subfamily definitions can do so. Source code is available on the Web page. The Berkeley Phylogenomics Group PhyloFacts resource contains pre-calculated subfamily predictions and subfamily HMMs for more than 40,000 protein families and domains at http://phylogenomics.berkeley.edu/phylofacts/
- …