~ QZ ~

Ternyata banyak sekali manfaat Teknologi Informasi dan Komunikasi dalam kehidupan kita sehari-hari.Misalnya dalam bidang pendidikan. Dengan pendidikan dimungkinkan terjadinya penyebarluasan Teknologi Informasi dan transformasi ilmu pengetahuan untuk sektor-sektor pendidikan. Para siswa yang duduk di bangku sekolah dan mahasiswa juga terbantu dengan adanya internet dalam mengerjakan tugas sekolah atau tugas kuliah. Para mahasiswa dapat mencari bahan skripsi di internet atau para siswa mencari bahan tugas makalahnya di internet. Dengan adanya pelajaran Teknologi Informasi dan Komunikasi di sekolah, para siswa dapat belajar dan memanfaatkan TIK dalam kehidupan mereka sehari-hari dengan baik.

Manfaat TIK tidak hanya pada bidang pendidikan saja, tetapi juga pada bidang ekonomi. TIK dapat mendorong usaha kecil dan menengah pedesaan agar dapat mendapatkan nilai lebih serta menggerakan roda perekonomian desa. Bayangkan manfaat yang didapat penduduk desa dalam mencari informasi terbaru tentang benih padi unggul, bibit uggul atau bibit unggul tanaman budidaya lainnya. Peternak juga bisa mengetahui produk unggulan peternakan. Lumayan membantu, kan?

Manfaat TIK lainnya dalam bidang e-education juga ada. Kita sudah mengenal program internet goes to school, community acces point, e-learning, smart campus.

Pemerintah juga harus menyiapkan perangkat peraturan terkait pembatasan kebebasan akses internet. Akses yang terlalu bebas bisa berakibat fatal bagi perkembangan masyarakat, terutama di daerah yang haus akan informasi.

Harus kita sadari, TIK khususnya internet hanyalah merupakan alat bantu saja dan bukan menjadi solusi dalam dunia pendidikan, formal maupun nonformal. Bagaimanapun pendidikan yang bermutu didapat dari para pendidik yang bermutu ditambah dukungan pemerintah dengan kurikulum yang sesuai dengan kebutuhan siswa didik yang diimplementasikan dengan benar dan kreatif.

Banyak sekali manfaat dari pelajaran Teknologi Informasi dan Komunikasi. Peningkatan kualitas hidup semakin menuntut manusia untuk melakukan berbagai aktifitas yang dibutuhkan dengan mengoptimalkan sumber daya yang dimilikinya. Teknologi Informasi dan Komunikasi yang perkembangannya begitu cepat secara tidak langsung mengharuskan manusia untuk menggunakannya dalam segala aktivitasnya. Beberapa penerapan dari Teknologi Informasi dan Komunikasi antara lain dalam perusahaan, dunia bisnis, sektor perbankan, pendidikan, dan kesehatan.


A. Penerapan Teknologi Informasi dan Komunikasi dalam Perusahaan

Penerapan Teknologi Informasi dan Komunikasi banyak digunakan para usahawan. Kebutuhan efisiensi waktu dan biaya menyebabkan setiap pelaku usaha merasa perlu menerapkan teknologi informasi dalam lingkungan kerja. Penerapan Teknologi Informasi dan Komunikasi menyebabkan perubahan bada kebiasaan kerja. Misalnya penerapan Enterprice Resource Planning (ERP). ERP adalah salah satu aplikasi perangkat lunak yang mencakup sistem manajemen dalam perusahaan.

B. Penerapan Teknologi Informasi dan Komunikasi dalam Dunia Bisnis Dalam dunia bisnis Teknologi Informasi dan Komunikasi dimanfaatkan untuk perdagangan secara elektronik atau dikenal sebagai E-Commerce. E-Commerce adalah perdagangan menggunakan jaringan komunikasi internet.

C. Penerapan Teknologi Informasi dan Komunikasi dalam Perbankan

Dalam dunia perbankan Teknologi Informasi dan Komunikasi adalah diterapkannya transaksi perbankan lewat internet atau dikenal dengan Internet Banking. Beberapa transaksi yang dapat dilakukan melalui Internet Banking antara lain transfer uang, pengecekan saldo, pemindahbukuan, pembayaran tagihan, dan informasi rekening.

D. Penerapan Teknologi Informasi dan Komunikasi dalam Pendidikan

Teknologi pembelajaran terus mengalami perkembangan seirng perkembangan zaman. Dalam pelaksanaan pembelajaran sehari-hari Makalah Teknologi Informasi dan Komunikasi sering dijumpai kombinasi teknologi audio/data, video/data, audio/video, dan internet. Internet merupakan alat komunikasi yang murah dimana memungkinkan terjadinya interaksi antara dua orang atau lebih. Kemampuan dan karakteristik internet memungkinkan terjadinya proses belajar mengajar jarak jauh (E-Learning) menjadi lebih efektif dan efisien sehingga dapat diperoleh hasil yang lebih baik.




E. Penerapan Teknologi Informasi dan Komunikasi dalam Kesehatan

Sistem berbasis kartu cerdas (smart card) dapat digunakan juru medis untuk mengetahui riwayat penyakit pasien yang datang ke rumah sakit karena dalam kartu tersebut para juru medis dapat mengetahui riwayat penyakit pasien. Digunakannya robot untuk membantu proses operasi pembedahan serta penggunaan komputer hasil pencitraan tiga dimensi untuk menunjukkan letak tumor dalam tubuh pasien.

1. Terhadap Kehidupan Bermasyarakat

Proses penggunaan teknologi informasi dan komunikasi merupakan dasar yang muncul dan dikenal sebagai Informatika Masyarakat. Masyarakat informatika melibatkan diri lebih dari sekedar pengadopsian teknologi informasi dan komunikasi di dalamnya, tetapi ikut dalam penerapan teknologi informasi dan komunikasi demi keuntungan masyarakat lokal. Masyarakat informatika tidak hanya menghadapkan teknologi, tetapi juga gagasan sosial yang dikenal sebagai modal sosial. Masyarakat informatika juga memperkenalkan dimensi baru ke dalam konsep pembagian masyarakat berdasarkan modal budaya dan kelas sosial yang menstratifikasi masyarakat.

Michael Gurstein, (Gurstein, 2000), mendeskripsikan masyarakat informasi dengan cara berikut: Masyarakat Informatika adalah aplikasi teknologi informasi dan komunikasi untuk memungkinkan proses masyarakat dan pencapaian tujuan masyarakat yang mencakup pembagian digital di dalam maupun antar masyarakat. Masyarakat informatika muncul sebagai kerangka untuk mendekati Sistem Informasi secara sistematis dari perspektif masyarakat dan sejajar dengan Sistem Informasi Manajemen dalam pengembangan strategi dan teknik untuk manajemen penggunaan dan aplikasi sistem informasi masyarakat.

Masyarakat informatika mengatasi hubungan antara teori akademik dan penelitian, masalah kebijakan dan pragmatis yang timbul dari puluhan ribu “Jaringan Masyarakat”, “Pusat Teknologi Masyarakat”, Telecentre, Pusat Komunikasi Masyarakat, dan Telecottage yang saat ini berada secara global.

Sebagai satu bidang akademik, masyarakat informatika mengambil sumber daya dan partisipan dari serangkaian latar belakang, termasuk Ilmu Komputer, Manajemen, Ilmu Informasi dan Perpustakaan, Perencanaan, Sosiologi, Pendidikan, Kebijakan Sosial, dan penelitian Pedesaan, Regional, dan Pembangunan.

Sebagai suatu praktik, masyarakat informatika merupakan kepentingan bagi mereka yang perhatian dengan Pengembangan Masyarakat dan Ekonomi Lokal di Negara Berkembang maupun Maju dan memiliki hubungan dekat dengan mereka yang bekerja di bidang-bidang seperti Pembangunan Masyarakat, Pembangunan Ekonomi Masyarakat, Informatika Kesehatan Berbasis Masyarakat, Pendidikan Dewasa dan Lanjutan.

Masyarakat informatika adalah bagian dari struktur masyarakat di dunia yang muncul dan memiliki peran di sejumlah tingkat fundamental dalam masyarakat yang berkembang. Masyarakat informatika dapat dideskripsikan sebagai penggunaan teknologi informasi dan komunikasi untuk praktik masyarakat, yang didefinisikan oleh Glen (1993) sebagai Penyampaian Layanan Masyarakat, dan Tindakan Masyarakat. Khususnya, Praktik Masyarakat semakin dianggap fundamental untuk masalah-masalah sosial karena masyarakat di suatu tempat menghadapi dunia perdagangan modern yang kurang menjadi subyek negara/ bangsa.

Komunikasi telah memainkan peranan penting dalam mengembangkan dan mempertahankan kesehjateraan masyarakat secara geografis sepanjang sejarah. Informatika Masyarakat adalah sebuah fenomena terkini pada masyarakat jaringan modern, dapat dilacak pada pemrakarsa komunikasi masyarakat akhir 1980 sampai awal 1990.

Sejak permulaan, tujuan utama teknologi masyarakat adalah untuk menggunakan prasarana, aplikasi, dan layanan informasi dan komunikasi untuk memberdayakan dan melestarikan modal sosial masyarakat lokal (jaringan, organisasi, kelompok, aktivitas, dan nilai yang mendasari kehidupan masyarakat).

1.Terhadap Pembelajaran di sekolah


Kita harus tahu bahwa untuk memanfaatkan TIK dalam hal pembelajaran tidak semudah dibayangkan.Perlu beberapa syarat yang harus dipenuhi demi terwujudnya pemanfaatan TIK dalam pembelajaran,diantaranya :
-Adanya akses teknologi internet untuk guru maupun siswa,baik di dalam kelas,sekolah,maupun lembaga pendidikan guru,
-Adanya materi yang bermutu bagi guru dan siswa,
-Guru harus harus produktif terhadap perkembangan TIK.

Selain itu,untuk menghindari pemanfaatan teknologi yang kurang bermanfaat apalagi dalam hal negatif oleh siswa karena pembelajaran TIK antar siswa dengan cepat maka mengarahkan pemanfatan TIK dalam pembelajaran menjadi sangat penting sehingga siswa disibukkan dengan eksplorasi subjek positif dalam penggunaan TIK.Bentuk nyatanya dapat berupa penugasan pencarian artikel,sumber bacaan,atau pengiriman tugas(PR) melalui e-mail

Dan juga harus tercipta kemudahan akses internet di lingkungan yang terkontrol seperti di sekolah atau rumah melebihi kemudahan akses di tempat umum seperti warnet agar aktivitas on-line siswa lebih terkontrol.

Beberapa pemanfaatan TIK dalam pembelajaran diantaranya :
-Presentasi
-Demonstrasi
-Kelas Virtual

Blog sekarang memang menjadi tempat bagi semua orang seperti pelajar untuk munumpahkan semua ilmu dan aktifitas sehari-harinya.Dengan menulis di Blog kita dapat :
-Mengembangakan kreatifitas kalian dalam menulis.Selain itu apabila tulisan kalian bagus maka kita akan mendapatkan komentar sebagai bentuk penghormatan terhadap tulisan kita,
-Mempersiapkan diri kita untuk bersaing di dunia global yang menuntut kita terjun dalam teknologi, nah apabila kita terbiasa menulis di Blog maka kita akan terbiasa menggunakan teknologi dalam menjalani kehidupan.

Dengan e-mail,kita bisa mengirimkan tugas yang diberikan oleh guru tanpa harus bertatap muka langsung.Dan dengan menjelajah internet,kita akan tahu banyak hal yang bisa di dapat melalui internet seperti mencari artikel yang berkaitan dengan mata pelajaran di sekolah.Ini semua sangat menunjang sekali terhadap proses belajar di sekolah.

Microsoft PowerPoint


Microsoft PowerPoint is a presentation program by Microsoft. It is part of the Microsoft Office suite, and runs on Microsoft Windows and Apple's Mac OS X operating system.


PowerPoint is used by business people, educators, students, and trainers. Beginning with Microsoft Office 2003, Microsoft revised the branding to emphasize PowerPoint's place within the office suite, calling it Microsoft Office PowerPoint instead of just Microsoft PowerPoint. The current versions are Microsoft Office PowerPoint 2010 for Windows and 2008 for Mac.

History


The first version of PowerPoint was initially developed on 14 August 1984 by Robert Gaskins and Dennis Austin of Forethought, Inc. of Sunnyvale, California. The original version of this program was created by Dennis Austin and Thomas Rudkin. Originally designed for the Macintosh computer, the initial release was called "Presenter". In 1987, it was renamed to "PowerPoint" due to problems with trademarks, the idea for the name coming from Robert Gaskins. In August of the same year, Forethought was bought by Microsoft for $14 million USD ($26.2 million in present-day terms), and became Microsoft's Graphics Business Unit, which continued to further develop the software.

PowerPoint changed significantly with PowerPoint 97. Prior to PowerPoint 97, presentations were linear, always proceeding from one slide to the next. PowerPoint 97 introduced hyperlinks, which allowed users to jump around during a presentation.
PowerPoint 2000 (and the rest of the Office 2000 suite) introduced a clipboard that could hold multiple objects at once. Another noticeable change was that the Office Assistant, whose frequent unsolicited appearance in PowerPoint 97 had annoyed many users, was changed to be less intrusive.

PowerPoint 2007 (and the rest of the Office 2007 suite) introduced a complete redesign of the user interface where commands could be found in the "ribbon," rather than in traditional menus.

Operation


PowerPoint presentations consist of a number of individual pages or "slides". The "slide" analogy is a reference to the slide projector, a device that has become obsolete with the use of PowerPoint and other presentation software. Slides may contain text, graphics, movies, and other objects, which may be arranged freely on the slide. PowerPoint, however, facilitates the use of a consistent style in a presentation using a template or "Slide Master".

The presentation can be printed, displayed live on a computer, or navigated through at the command of the presenter. For larger audiences the computer display is often projected using a video projector. Slides can also form the basis of webcasts.

Cultural impact


Supporters and critics generally agree that the ease of use of presentation software can save a lot of time for people who otherwise would have used other types of visual aid—hand-drawn or mechanically typeset slides, blackboards or whiteboards, or overhead projections. Ease of use also encourages those who otherwise would not have used visual aids, or would not have given a presentation at all, to make presentations. As PowerPoint's style, animation, and multimedia abilities have become little more sophisticated, and as the application has generally made it easier to produce presentations (even to the point of having an "AutoContent Wizard" (discontinued in PowerPoint 2007) suggesting a structure for a presentation), the difference in needs and desires of presenters and audiences has become more noticeable.

The benefit of PowerPoint is continually debated. Its use in classroom lectures has influenced investigations of PowerPoint’s effects on student performance in comparison to lectures based on overhead projectors, traditional lectures, and online lectures. Not only is it a useful tool for introductory lectures, but it is also has many functions that allow for review games, especially in the younger grades. There are no compelling results to prove or disprove that PowerPoint is more effective for learner retention than traditional presentation methods. The effect on audiences of poor PowerPoint presentations has been described as PowerPoint hell.

PowerPoint Viewer


The Microsoft Office PowerPoint Viewer is a program used to run presentations on computers that don't have Microsoft PowerPoint installed. The Office PowerPoint Viewer is added by default to the same disk or network location that contains one or more presentations you packaged by using the Package for CD feature.

The PowerPoint Viewer is installed by default with a Microsoft Office 2003 installation for use with the Package for CD feature. The PowerPoint Viewer file is also available for download from the Microsoft Office Online Web site.

Presentations password-protected for opening or modifying can be opened by the PowerPoint Viewer. The Package for CD feature allows you to package any password-protected file or set a new password for all packaged presentations. The PowerPoint Viewer prompts you for a password if the file is open password-protected.

The PowerPoint Viewer supports opening presentations created using PowerPoint 97 and later. In addition, it supports all file content except OLE objects and scripting.

File formats


The binary format specification has been available from Microsoft on request, but since February 2008 the .ppt format specification can be freely downloaded.

In Microsoft Office 2007 the binary file formats were replaced as the default format by the new XML based Office Open XML formats, which are published as an open standard. Nevertheless, they are not complete as there are binary blobs inside of the XML files, and several pieces of behaviour are not specified but refer to the observed behaviour of specific versions of Microsoft product.

From Wikipedia, the free encyclopedia

Microsoft Excel


Microsoft Excel (full name Microsoft Office Excel) is a spreadsheet application written and distributed by Microsoft for Microsoft Windows and Mac OS X. It features calculation, graphing tools, pivot tables and a macro programming language called VBA (Visual Basic for Applications). It has been the most widely used spreadsheet application available for these platforms since version 5 in 1993[citation needed]. Excel forms part of Microsoft Office.




History

Excel 2.0

Microsoft originally marketed a spreadsheet program called Multiplan in 1982. Multiplan became very popular on CP/M systems, but on MS-DOS systems it lost popularity to Lotus 1-2-3. Microsoft released the first version of Excel for the Mac in 1985, and the first Windows version (numbered 2.05 to line up with the Mac and bundled with a run-time Windows environment) in November 1987. Lotus was slow to bring 1-2-3 to Windows and by 1988 Excel had started to outsell 1-2-3 and helped Microsoft achieve the position of leading PC software developer. This accomplishment, dethroning the king of the software world, solidified Microsoft as a valid competitor and showed its future of developing GUI software. Microsoft pushed its advantage with regular new releases, every two years or so. The current version for the Windows platform is Excel 12, also called Microsoft Office Excel 2007. The current version for the Mac OS X platform is Microsoft Excel 2008.

Early in 1993 Excel became the target of a trademark lawsuit by another company already selling a software package named "Excel" in the finance industry. As the result of the dispute Microsoft had to refer to the program as "Microsoft Excel" in all of its formal press releases and legal documents. However, over time this practice has been ignored, and Microsoft cleared up the issue permanently when they purchased the trademark of the other program.[citation needed] Microsoft also encouraged the use of the letters XL as shorthand for the program; while this is no longer common, the program's icon on Windows still consists of a stylized combination of the two letters, and the file extension of the default Excel format is .xls.

Excel offers many user interface tweaks over the earliest electronic spreadsheets; however, the essence remains the same as in the original spreadsheet software, VisiCalc: the program displays cells organized in rows and columns, and each cell may contain data or a formula, with relative or absolute references to other cells.

Excel became the first spreadsheet to allow the user to define the appearance of spreadsheets (fonts, character attributes and cell appearance). It also introduced intelligent cell recomputation, where only cells dependent on the cell being modified are updated (previous spreadsheet programs recomputed everything all the time or waited for a specific user command). Excel has extensive graphing capabilities, and enables users to perform mail merge.

Since 1993 Excel has included Visual Basic for Applications (VBA), a programming language based on Visual Basic which adds the ability to automate tasks in Excel and to provide user-defined functions (UDF) for use in worksheets. VBA is a powerful addition to the application which, in later versions, includes a fully featured integrated development environment (IDE). Macro recording can produce VBA code replicating user actions, thus allowing simple automation of regular tasks. VBA allows the creation of forms and in-worksheet controls to communicate with the user. The language supports use (but not creation) of ActiveX (COM) DLL's; later versions add support for class modules allowing the use of basic object-oriented programming techniques.

The automation functionality provided by VBA made Excel a target for macro viruses. This caused serious problems until antivirus products began to detect these viruses. Microsoft belatedly took steps to prevent the misuse by adding the ability to disable macros completely, to enable macros when opening a workbook or to trust all macros signed using a trusted certificate.

Excel 5.0

Versions 5.0 to 9.0 of Excel contain various Easter eggs, although since version 10 Microsoft has taken measures to eliminate such undocumented features from their products.

Excel 2000

For many users, one of the most obvious changes introduced with Excel 2000 (and the rest of the Office 2000 suite) involved a clipboard that could hold multiple objects at once. In another noticeable change the Office Assistant, whose frequent unsolicited appearance in Excel 97 had annoyed many users, became less intrusive.


From Wikipedia, the free encyclopedia

Microsoft Word
 


History


Word 1981 to 1989

Concepts and ideas of Word were brought from Bravo, the original GUI writing word processor developed at Xerox PARC on February 1, 1983. With this, development on what was originally named Multi-Tool Word began.

Richard Brodie renamed it Microsoft Word, and Microsoft released the program on October 25, 1983, for the IBM PC. Free demonstration copies of the application were bundled with the November 1983 issue of PC World, making it the first program to be distributed on-disk with a magazine. However, it was not well received, and sales lagged behind those of rival products such as WordPerfect. Although MS-DOS was a character-based system, Microsoft Word was the word processor for the IBM PC that showed actual line breaks and typeface markups such as bold and italics directly on the screen while editing, although this was not a true WYSIWYG system because available displays did not have the resolution to show actual typefaces. Other DOS word processors, such as WordStar and WordPerfect, used simple text only display with markup codes on the screen or sometimes, at the most, alternative colors.

As with most DOS software, each program had its own, often complicated set of commands and nomenclature for performing functions that had to be learned. For example, in Word for MS-DOS, a file would be saved with the sequence Escape-T-S: pressing Escape called up the menu box, T accessed the set of options for Transfer and S was for Save (the only similar interface belonged to Microsoft's own Multiplan spreadsheet). As most secretaries had learned how to use WordPerfect, companies were reluctant to switch to a rival product that offered few advantages. Desired features in Word such as indentation before typing (emulating the F4 feature in WordPerfect), the ability to block text to copy it before typing, instead of picking up mouse or blocking after typing and a reliable way to have macros and other functions that always replicate the same function time after time, were just some of Word's problems for production typing.

Word for Macintosh, despite of the major differences in look and feel from the DOS version, was ported by Ken Shapiro with only minor changes from the DOS source code, which had been written with high-resolution displays and laser printers in mind although none were yet available to the general public. Following the precedents of LisaWrite and MacWrite, Word for Macintosh attempted to add closer WYSIWYG features into its package. After Word for Mac was released in 1985, it gained wide acceptance.

There was no Word 2.0 for Macintosh. Instead, the second release of Word for Macintosh, shipped in 1987, was named Word 3.0; this was Microsoft's first attempt to synchronize version numbers across platforms. Word 3.0 included numerous internal enhancements and new features including the first implementation of the Rich Text Format (RTF) specification, but was plagued with bugs. Within a few months Word 3.0 was superseded by Word 3.01, which was much more stable. All registered users of 3.0 were mailed free copies of 3.01, making this one of Microsoft's most expensive mistakes up to that time
In 1986, an agreement between Atari and Microsoft brings Word to the Atari ST. The Atari ST version was a translation of Word 1.05 for the Apple Macintosh, however it was released under the name Microsoft Write (the name of the word processor included with Windows during the 80s and early 90s). Unlike other versions of Word, the Atari version was a one time release with no future updates or revisions. The release of Microsoft Write was one of two major PC applications that were released for the Atari ST (the other application being WordPerfect). Microsoft Write was released for the Atari ST in 1988.

Word 2007

Siput Pertama Berbadan Setengah Flora Setengah Fauna


Rabu, 13 Januari 2010
18:27 WIB


Para ilmuwan memperkirakan, siput cerdik tersebut mencuri gen dari alga yang mereka makan sehingga bisa menghasilkan klorofil. Dengan gen "curian", mereka bisa berfotosintesis, yaitu proses tumbuhan untuk mengubah cahaya matahari menjadi energi.

"Hewan ini bisa membuat molekul berisi energi tanpa makan apa-apa," kata Sydney Pierce, pakar biologi dari Universitas South Florida di Tampa. Pierce telah mempelajari mahluk unik tersebut, yang telah resmi dinamakan Elysia chlorotica, selama 20 tahun.

Ia mengajukan temuan terbarunya pada tanggal 7 Januari 2010, pada pertemuan tahunan Komunitas Integratif dan Perbandingan Biologi di Seattle. Temuan ini dilaporkan pertama kali oleh jurnal Science. "Ini pertama kalinya hewan multiseluler bisa menghasilkan klorofil," tutur Pierce.

Siput laut ini tinggal di rawa-rawa air asin di New England, Kanada. Selain "mencuri" gen untuk menghasilkan pigmen hijau klorofil, hewan ini juga mencuri bagian-bagian kecil sel yang disebut kloroplas, yang dipakai untuk melakukan fotosintesis. Kloroplas menggunakan klorofil untuk mengubah cahaya matahari menjadi energi, seperti tanaman, sehingga hewan ini tak perlu makan untuk mendapatkan energi.

"Kami mengumpulkan sejumlah hewan tersebut dan menyimpannya di akuarium selama berbulan-bulan," kata Pierce, "Asalkan diberi cahaya selama 12 jam sehari, mereka bisa bertahan (tanpa makan)."

Para peneliti memakai pelacak radioaktif untuk memastikan bahwa siput-siput ini benar-benar menghasilkan klorofil, dan bukan mencurinya dari pigmen yang sudah pada alga. Nyatanya, siput-siput ini mengintegrasikan materi genetika dengan sangat sempurna sehingga bisa diturunkan pada generasi selanjutnya.

Anak-anak dari siput yang sudah "mencuri" gen juga bisa menghasilkan klorofil sendiri, walaupun mereka tak bisa berfotosintesis sebelum mereka makan cukup alga hingga bisa "mencuri" cukup kloroplas. Sejauh ini, kloroplasnya belum bisa mereka produksi sendiri. Keberhasilan siput-siput ini mengagumkan, dan para ilmuwan juga masih belum bisa memastikan, bagaimana hewan ini bisa memilih gen yang mereka butuhkan.

"Mungkin saja DNA dari satu spesies bisa masuk ke spesies yang lain, seperti yang telah dibuktikan oleh siput jenis ini. Tapi mekanismenya masih belum diketahui," ungkap Pierce.

Sumber: Kompas.com

Piano










While the clavichord allowed expressive control of volume and sustain, it was too quiet for large performances. The harpsichord produced a sufficiently-loud sound, but had little expressive control over each note. The piano was likely formed as an attempt to combine loudness with control, avoiding the trade-offs of available instruments.


Cristofori's great success was in solving, without any prior example, the fundamental mechanical problem of piano design: the hammer must strike the string, but not remain in contact with it (as a tangent remains in contact with a clavichord string) because this would damp the sound. Moreover, the hammer must return to its rest position without bouncing violently, and it must be possible to repeat a note rapidly. Cristofori's piano action served as a model for the many different approaches to piano actions that followed. While Cristofori's early instruments were made with thin strings and were much quieter than the modern piano, compared to the clavichord (the only previous keyboard instrument capable of minutely controlled dynamic nuance through the keyboard) they were considerably louder and had more sustaining power.


Cristofori's new instrument remained relatively unknown until an Italian writer, Scipione Maffei, wrote an enthusiastic article about it (1711), including a diagram of the mechanism. This article was widely distributed, and most of the next generation of piano builders started their work because of reading it. One of these builders was Gottfried Silbermann, better known as an organ builder. Silbermann's pianos were virtually direct copies of Cristofori's, with one important addition: Silbermann invented the forerunner of the modern damper pedal, which lifts all the dampers from the strings at once.


Silbermann showed Johann Sebastian Bach one of his early instruments in the 1730s, but Bach did not like it at that time, claiming that the higher notes were too soft to allow a full dynamic range. Although this earned him some animosity from Silbermann, the criticism was apparently heeded. Bach did approve of a later instrument he saw in 1747, and even served as an agent in selling Silbermann's pianos.


Piano making flourished during the late 18th century in the Viennese school, which included Johann Andreas Stein (who worked in Augsburg, Germany) and the Viennese makers Nannette Streicher (daughter of Stein) and Anton Walter. Viennese-style pianos were built with wood frames, two strings per note, and had leather-covered hammers. Some of these Viennese pianos had the opposite coloring of modern-day pianos; the natural keys were black and the accidental keys white. It was for such instruments that Wolfgang Amadeus Mozart composed his concertos and sonatas, and replicas of them are built today for use in authentic-instrument performance of his music. The pianos of Mozart's day had a softer, clearer tone than today's pianos or English pianos, with less sustaining power. The term fortepiano is nowadays often used to distinguish the 18th-century instrument from later pianos.


The modern piano (the pianoforte) was developed from the harpsichord around 1720, by Bartolomeo Cristofori of Padua, Italy. His new instrument had a delicate pianissimo (very soft sound), a strong fortissimo (a very loud, forceful sound), and every level in between. The first upright piano was made around 1780 by Johann Schmidt of Salzburg, Austria. Thomas Loud of London developed an upright piano whose strings ran diagonally (in 1802), saving even more space.


Development of the modern piano


In the period lasting from about 1790 to 1860, the Mozart-era piano underwent tremendous changes that led to the modern form of the instrument. This revolution was in response to a consistent preference by composers and pianists for a more powerful, sustained piano sound, and made possible by the ongoing Industrial Revolution with technological resources such as high-quality steel, called piano wire, for strings, and precision casting for the production of iron frames. Over time, the tonal range of the piano was also increased from the five octaves of Mozart's day to the 7¼ or more octaves found on modern pianos.





One of the major technical innovations that helped to create the sound of the modern piano was the use of a strong iron frame. Also called the "plate", the iron frame sits atop the soundboard, and serves as the primary bulwark against the force of string tension. The increased structural integrity of the iron frame allowed the use of thicker, tenser, and more numerous strings. In a modern grand the total string tension can exceed 20 tons. The single piece cast iron frame was patented in 1825 in Boston by Alpheus Babcock, combining the metal hitch pin plate (1821, claimed by Broadwood on behalf of Samuel Hervé) and resisting bars (Thom and Allen, 1820, but also claimed by Broadwood and Érard). Babcock later worked for the Chickering & Mackays firm who patented the first full iron frame for grand pianos in 1843. Composite forged metal frames were preferred by many European makers until the American system was fully adopted by the early 20th century.


Other innovations for the mechanism included the use of felt hammer coverings instead of layered leather hammers. Felt hammers, which were first introduced by Henri Pape in 1826, were a more consistent material, permitting wider dynamic ranges as hammer weights and string tension increased. The sostenuto pedal (see below), invented in 1844 by Jean Louis Boisselot and improved by the Steinway firm in 1874, allowed a wider range of effects.


Other important technical innovations of this era included changes to the way the piano was strung, such as the use of a "choir" of three strings rather than two for all but the lower notes, and the use of different stringing methods. With the over strung scale, also called "cross-stringing", the strings are placed in a vertically overlapping slanted arrangement, with two heights of bridges on the soundboard instead of just one. This permits larger, but not necessarily longer, strings to fit within the case of the piano. Over stringing was invented by Jean-Henri Pape during the 1820s, and first patented for use in grand pianos in the United States by Henry Steinway, Jr. in 1859.

Duplex scaling: Treble strings of a 182 cm. grand piano. From lower left to upper right: dampers, main sounding length of strings, treble bridge, duplex string length, duplex bridge (long bar perpendicular to strings), hitchpins


With duplexes or aliquot scales, which was patented in 1872 by Theodore Steinway, the different components of string vibrations are controlled by tuning their secondary parts in octave relationships with the sounding lengths. Similar systems developed by Blüthner (1872), as well as Taskin (1788), and Collard (1821) used more distinctly ringing undamped vibrations to modify tone.




The very tall cabinet piano was introduced about 1805 and was built through the 1840s. It had strings arranged vertically on a continuous frame with bridges extended nearly to the floor, behind the keyboard and very large sticker action. The short cottage upright or pianino with vertical stringing, made popular by Robert Wornum around 1815, was built into the 20th century. They are informally called birdcage pianos because of their prominent damper mechanism. Pianinos were distinguished from the oblique, or diagonally strung upright made popular in France by Roller & Blanchet during the late 1820s. The tiny spinet upright was manufactured from the mid-1930s until recent times. The low position of the hammers required the use of a "drop action" to preserve a reasonable keyboard height.


Modern upright and grand pianos attained their present forms by the end of the 19th century. Improvements have been made in manufacturing processes, and many individual details of the instrument continue to receive attention.

From: Wikipedia, the free encyclopedia

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