476 research outputs found

    Anatomy of an organizational change effort at the Lewis Research Center

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    By 1979, after a long decline following the end of the Apollo program, the Lewis Research Center found its very existence endangered because it was not doing the kind of research that could attract funding at the time. New management under Andrew J. Stofan applied a program of strategic planning, participative management, and consensus decision making. A corporate-cultural change was effected which enabled Lewis to commit itself to four fundable research and development projects. Morale-building and training programs which were essential to this change are described

    Individuals that are consistent in risk-taking benefit during collective foraging

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    It is well established that living in groups helps animals avoid predation and locate resources, but maintaining a group requires collective coordination, which can be difficult when individuals differ from one another. Personality variation (consistent behavioural differences within a population) is already known to be important in group interactions. Growing evidence suggests that individuals also differ in their consistency, i.e. differing in how variable they are over time, and theoretical models predict that this consistency can be beneficial in social contexts. We used three-spined sticklebacks (Gasterosteus aculeatus) to test whether the consistency in, as well as average levels of, risk taking behaviour (i.e. boldness) when individuals were tested alone affects social interactions when fish were retested in groups of 2 and 4. Behavioural consistency, independently of average levels of risk-taking, can be advantageous: more consistent individuals showed higher rates of initiating group movements as leaders, more behavioural coordination by joining others as followers, and greater food consumption. Our results have implications for both group decision making, as groups composed of consistent individuals are more cohesive, and personality traits, as social interactions can have functional consequences for consistency in behaviour and hence the evolution of personality variation

    Perancangan Dan Implementsi Alat Ukur Daya Listrik Arus Bolak-Balik Satu Fasa Berbasis Personal Computer

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    Design measurement instrument is not easy. Because that instrument to measure something, it is mean that used as reference, so in designing the used reference is as good as possible. Measuring electric power can be done in many ways, measure voltage, current, and power factor then cross that is the one way. This electric power equipment for measure electronic equipment and electrics equipment. Analog to Digital Converter (ADC) determines the capability of this Digital Measurement Instrument. ADC0804LCN is product of National Semiconductor, one of ADC can be used. ADC0804LCN is 8bit resolution ADC with serial control. Maximum clock is 640 KHz determining data transfer rate. Microcontroller is used to control ADC0804LCN

    Perancangan Program Aplikasi Customer Service Berbasis Online

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    Kegiatan bisnis Perusahaan saat ini yang dapat didukung oleh teknologi informasi dapat digunakan juga untuk divisi customer service dalam melakukan pelayanan service. Salah satu bidang bisnis yang akan dibahas dalam skripsi ini adalah program aplikasi customer service berbasis online untuk menghubungkan dengan teknologi informasi maka diperlukan dukungan kajian ilmu dalam pengembangan sistem informasi, kajian ilmu tersebut yaitu sistem informasi. Sistem informasi adalah proses yang menjalankan fungsi mengumpulkan, memproses, menyimpan, menganalisis, dan menyebarkan informasi untuk tujuan tertentu. Metodologi yang dipakai dalam perancangan applikasi ini adalah System Development Life Cycle (SDLC). Dengan adanya aplikasi customer serivce yang sudah berbasis online dapat memudahkan staff bagian customer serivice dalam melakukan aktivitas menerima dan mengatur jadwal perbaikan. Sistem ini dirancang untuk membantu staff customer service dalam mencatat permintaan perbaikan, jadwal kunjungan dan memberikan laporan tentang customer service yang terdapat di divisi customer service

    The relationship between ABO/rhesus blood groups and type 2 diabetes mellitus in Maghnia, western Algeria

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    Background: To determine the relationship between ABO/rhesus (Rh) blood groups and type 2 diabetes mellitus in a western Algerian population.Method: This case-control study was conducted at the Regional Hospital Centre of Maghnia, Tlemcen, from July 2008 to May 2009, involving 280 patients with type 2 diabetes mellitus and 271 healthy controls. Blood samples were collected from the patients after consent had been obtained. The samples were tested for ABO and Rh blood groups, using the Beth-Vincent and Simonin-Michon methods. The allele frequencies were calculated according to the Bernstein formulas. Results: The χ2 test results showed that there was no association between the ABO blood group and type 2 diabetes mellitus. It was also noted that the O blood group was distributed with the highest frequency among diabetic subjects (52.85%). For the Rh system, d allele frequency presence was higher in diabetics than in nondiabetics (0.3778 and 0.3644 respectively). The difference between phenotype frequencies was not significant (p = 0.733). The distribution of ABO/Rh blood groups between gender and ethnic group showed no significant difference (p > 0.05). Conclusion: Our study confirms that there is no association between ABO/Rh blood group and diabetes mellitus in this Algerian population.Keywords: ABO, rhesus, type 2 diabetes, Algeri

    Persistent androgen receptor-mediated transcription in castration-resistant prostate cancer under androgen-deprived conditions

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    The androgen receptor (AR) is a ligand-inducible transcription factor that mediates androgen action in target tissues. Upon ligand binding, the AR binds to thousands of genomic loci and activates a cell-type specific gene program. Prostate cancer growth and progression depend on androgen-induced AR signaling. Treatment of advanced prostate cancer through medical or surgical castration leads to initial response and durable remission, but resistance inevitably develops. In castration-resistant prostate cancer (CRPC), AR activity remains critical for tumor growth despite androgen deprivation. Although previous studies have focused on ligand-dependent AR signaling, in this study we explore AR function under the androgen-deprived conditions characteristic of CRPC. Our data demonstrate that AR persistently occupies a distinct set of genomic loci after androgen deprivation in CRPC. These androgen-independent AR occupied regions have constitutively open chromatin structures that lack the canonical androgen response element and are independent of FoxA1, a transcription factor involved in ligand-dependent AR targeting. Many AR binding events occur at proximal promoters, which can act as enhancers to augment transcriptional activities of other promoters through DNA looping. We further show that androgen-independent AR binding directs a gene expression program in CRPC, which is necessary for the growth of CRPC after androgen withdrawal

    Changes in soil properties following the establishment of exclosures in Ethiopia : a meta-analysis

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    Acknowledgements This work is part of the RALENTIR (Reducing land degradation and carbon loss from Ethiopia's soils to strengthen livelihoods and resilience) project, funded by GCRF (Global Challenges Research Fund) and University of Aberdeen. We are grateful to Abeyou Wale for his assistance in developing the map of agroecological zones of Ethiopia.Peer reviewedPublisher PD

    Multivariate phenotypic divergence due to the fixation of beneficial mutations in experimentally evolved lineages of a filamentous fungus

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    The potential for evolutionary change is limited by the availability of genetic variation. Mutations are the ultimate source of new alleles, yet there have been few experimental investigations of the role of novel mutations in multivariate phenotypic evolution. Here, we evaluated the degree of multivariate phenotypic divergence observed in a long-term evolution experiment whereby replicate lineages of the filamentous fungus Aspergillus nidulans were derived from a single genotype and allowed to fix novel (beneficial) mutations while maintained at two different population sizes. We asked three fundamental questions regarding phenotypic divergence following approximately 800 generations of adaptation: (1) whether divergence was limited by mutational supply, (2) whether divergence proceeded in relatively many (few) multivariate directions, and (3) to what degree phenotypic divergence scaled with changes in fitness (i.e. adaptation). We found no evidence that mutational supply limited phenotypic divergence. Divergence also occurred in all possible phenotypic directions, implying that pleiotropy was either weak or sufficiently variable among new mutations so as not to constrain the direction of multivariate evolution. The degree of total phenotypic divergence from the common ancestor was positively correlated with the extent of adaptation. These results are discussed in the context of the evolution of complex phenotypes through the input of adaptive mutation

    Penerapan Model Problem Based Learning (PBL) Berbasis Pendekatan Saintifik untuk Meningkatkan Penguasaan Konsep pada Materi Pokok Kelarutan dan Hasil Kali Kelarutan

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    Telah dilakukan penelitian yang bertujuan untuk mengetahui keefektifan penerapan model problem based learning berbasis pendekatan saintifik terhadap penguasaan konsep. Desain penelitian menggunakan  pretest-posttest  control  group  design.  Populasi  penelitian  ini  terbagi  atas  dua  kelas paralel  sebanyak  58  siswa.  Teknik  pengambilan  sampel  menggunakan  teknik  purposive  sampling. Sampel penelitian ini yaitu kelas XI-IPA4  sebagai kelas eksperimen sebanyak 29 siswa dan kelas XI- IPA1   sebagai kelas kontrol sebanyak 29 siswa. Instrumen penelitian untuk menentukan karakteristik konsep menggunakan format analisis konsep dan format peta konsep. Profil penguasaan konsep menggunakan butir tes pilihan ganda beralasan sebanyak 10 nomor. Peningkatan penguasaan konsep menggunakan  rumus  N-gain.  Efektivitas  pembelajaran  menggunakan  rumus  uji  beda  (t).  Serta tanggapan siswa menggunakan angket. Berdasarkan hasil analisis ditemukan data: (1) Terdapat 14 label  konsep  pada  materi  pokok  Kelarutan  dan  Hasil  Kali  Kelarutan,  terdiri  dari  28%  konsep menyatakan prinsip abstrak meliputi: Kesetimbangan Kelarutan, Hasil Kali Ion Kesetimbangan (Ksp), Hasil Kali Ion (Qsp), dan Elektrolit Sukar Larut, terdapat 14,29% konsep yang menyatakan ukuran atribut meliputi: Suhu dan Derajat Keasaman (pH), Serta terdapat 57,14% konsep yang menyatakan proses meliputi: Kelarutan, Ion Senama, Pengendapan, Larutan Elektrolit, Elektrolit Biner, Elektrolit Terner, Elektrolit Kuarterner, Larutan Jenuh; (2) Diperoleh perbandingan rerata skor post-test tertinggi dan terendah penguasaan konsep siswa kelas eksperimen dan kelas kontrol. Perbandingan untuk skor post-test tertinggi yaitu 97,04>94,58 pada label konsep Larutan Jenuh, sedangkan perbandingan skor post-test terendah kelas eksperimen yaitu 72,70 pada label konsep Elektrolit Terner dan 70,43% pada kelas kontrol; (3) Indeks N-gain kelas eksperimen sebesar 0,77 berkategori tinggi dibandingkan kelas kontrol sebesar 0,70 berkategori sedang; (4) Penerapan model problem based learning berbasis pendekatan saintifik pada kelas eksperimen efektif meningkatkan penguasaan konsep siswa dengan post-test dan N-gain sig. (2-tailed) < 0,05, selanjutnya efektif untuk diterapkan pada kelompok siswa berkemampuan tinggi dan sedang; (5) Penerapan model problem based learning berbasis pendekatan saintifik memiliki tanggapan baik dengan persentase 75,16%. Kata kunci Model Problem Based Learning, Pendekatan Saintifik, Penguasaan Konsep, Kelarutan dan Hasil Kali KelarutanHas conducted research that aims to determine the effectiveness of the application of models problem based learning based on a scientific approach to the mastery of concepts. The study design using pretest-posttest control group. The study population was divided into two parallel classes as many as 58 students. The sampling technique used technique. purposive sampling Samples of this research is class XI-IPA4 as an experimental class at 29 students and class XI IPA1 as the control class as many as 29 students. Research instruments to determine the characteristics of the concept of using the format of concept analysis and concept map format. Profile mastery of concepts using reasoned multiple choice test items as much as 10 numbers. Increasing mastery of the concept of using formula. The N-gain The effectiveness of learning using different test formula (t). As well as the responses of students using a questionnaire. Based on the analysis found the data: (1) There are 14 label concept in the   subject matter  solubility  and  solubility  product,  consisting  of  28%  concept  stating  abstract principles include:  Equilibrium  Solubility,  K o n s t a n t a  S o l u b i l i t y  P r o d u c t  (Ksp),  Q u o s i e n  S o l u b i l i t y P r o d u c t  (Qsp), and the electrolyte is difficult Late, there are 14.29% concept that states the size of the attributes include: temperature and degree of acidity (pH), as well  as 57.14% are concepts that  express  the process include: solubility, homogenity ion, Precipitation, electrolytes, electrolytes binary, ternary electrolytes, electrolytes Quaternary, Saturated solution; (2) Obtained comparisonmean score of post- test  the  highest  and  lowest  grade  students  mastery  of  concept  experiment  and control   class. Comparison of scores post-test highest, 97.04> 94.58 on the label Saturated Solution concept, while the scores compare post-test experimental class that is 72.70 lows on the label concept ternary electrolytes and 70.43% in the control group; (3) The N-Indexgain of 0.77 categorized experimental class  higher  than  the  control  class  was  0.70  category  being;  (4)  The  application  of models problem based learning based on experimental class scientific approach effectively improve the mastery of concepts students with post-test and N-gain sig. (2-tailed) <0,05, then effective to apply to groups of high and medium-ability students; (5) The application ofmodels problem based learning based on scientific approach has a good response with the percentage of 75.16%.  Keywords Problem Based Learning Model, Approach Scientific, Control Concepts, solubility and Solubility Product Constant
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