Perbedaan Antara Otak Ekstrovert dan Introvert

Sedari dulu para ilmuwan mencoba meneliti bagaimana proses di otak mereka yang ekstrovert dan introvert.

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Mereka yang ekstrovert dan introvert memiliki cara pemrosesan di otak yang berbeda. Hasil penelitian yang dirilis oleh jurnal Frontiers in Human Neuroscience menemukan bahwa mereka yang ekstrovert akan lebih mengasosiasikan rasa bahagia pada lingkungan mereka.

Sedari dulu para ilmuwan mencoba meneliti bagaimana proses di otak mereka yang ekstrovert dan introvert. Peneliti menyimpulkan bahwa mereka yang ekstrovert menyukai pujian dan lebih berfokus pada wajah. Di sisi lain, mereka yang introvert sulit menerima terlalu banyak rangsangan dan lebih memperhatikan detail.

Yu Fu dan Richard Depue, ahli saraf dari Cornell University di New York, melakukan tes kepribadian pada mahasiswa baru. Partisipan mengkonsumsi ritalin, stimulan yang biasanya dipakai untuk menanggulangi gangguan akibat kurang perhatian atau malah hiperaktif (attention-deficit/hyperactivity disorder, atau ADHD). Ritalin merangsang munculnya dopamin yang memegang peran dalam motivasi. Sementara itu pada waktu yang sama partisipan menonton video.

Sesudahnya tim peneliti menguji bagaimana partisipan mengasosiasikan video dan lingkungannya serta hubungannya dengan dopamin yang terangsang Ritalin. Hasilnya efek Ritalin pada sistem dopamine tidak menjadi motivasi bagi mereka yang introvert. Ini berarti bahwa introvert memiliki pemrosesan yang berbeda mengenai apa ganjaran dari lingkungan dengan otak introvert lebih memikirkan apa yang ada dalam pikiran daripada motivasi eksternal. 

Penemuan ini menemukan hubungan antara sifat pribadi pada pemrosesan di sistem saraf manusia.
(Mohamad Takdir, Sumber: intisari-online.com, Huffington Post, http://nationalgeographic.co.id/berita/2013/08/perbedaan-antara-otak-ekstrovert-dan-introvert)

The Effect of Cultural Eutrofication For Our Water Environment Continuity

An activity of human has bothered the freshwater ecosystems passing what refer as cultural eutrofication. Cultural eutrofication was a made-up the density of photosynthetic organism by explosive that happened in water environment. A dismissal of liquid waste from factory, streams a surface of livestock dismissal from place of livestock animal, and fertilize from agriculture area, have encumbered the current water with anorganic nutrient so that cause explosion of population algae and sianobattery. The Population explosion causes the lower territorial water area becomes closed over by gulma, that making transportation irrigate and fish arrest not possible to conduct. Others, explosion of algae population sometime result the more oxygen production during daytime, but less at night amount the effect of respiration by a lot of population photosynthetic organism. When photosynthetic organism dead and organic substance accumulate in base water territorial, other organism like as detritivora use all oxygen in deeper water. All this influence causes some organism not possible to live. For example, cultural eutrofication at Erie Lake made the fish population which commercially had dead. After the time of they made a tighter regulation about waste dismissal in lake, so that enable some fish population to grow up return.

Hukum Mendel dalam Kehidupan Manusia

Hukum Mendel adalah hukum mengenai pewarisan sifat pada organisme. Hukum ini terdiri dari dua bagian, yaitu:

Hukum pemisahan (segregasi)

Hukum pemisahan menyatakan tiga hal pokok yaitu sebagai berikut:

·       Gen memiliki bentuk-bentuk alternatif yang mengatur variasi pada karakter keturunannya

·       Setiap individu membawa sepasang gen, satu dari induk jantan dan satu dari induk betina

·   Jika sepasang gen merupakan dua alel (bentuk alternatif dari gen yang mengatur variasi karakter) yang berbeda, alel dominan akan selalu terekspresikan dan alel resesif yang tertutupi oleh alel dominan akan tetap diwariskan ke keturunannya

 Hukum perpasangan bebas (asortasi)

Hukum perpasangan bebas menyatakan bila individu mempunyai dua pasang atau lebih sifat, maka akan diturunkan sepasang sifat secara bebas pada keturunannya tidak bergantung pada pasangan sifat yang lain. Dengan kata lain, alel dengan gen, sifat yang berbeda tidak saling mempengaruhi. Hal ini menjelaskan bahwa gen yang menentukan warna kulit tidak berpengarus pada kriting atau lurusnya rambut yang dimiliki oleh individu.

(Referensi teori Hukum Mendel diambil dari modul kuliah Hukum Mendel oleh: dr. Pratika Yuhyi Hernanda, Msc lulusan Erasmus University Rotterdam, Netherland (Belanda) dalam bidang keahlian Genetics Epidemiology dan bekerja sebagai dosen di Universitas Wijaya Kusuma dalam bidang Medical Genetics)

Jadi, inti dari Hukum Mendel adalah mengenai cara kerja gen dalam pewarisan sifat dan variasi karakter individu.

            Dalam bahasan yang lebih jauh lagi, mungkin banyak yang bertanya-tanya mengenai apa sebenarnya hubungan antara Hukum Mendel dengan kehidupan? Pada manusia, ada banyak kelainan-kelainan yang mengikuti pola pewarisan Hukum Mendel. Para peneliti menemukan bahwa ada ribuan kelainan genetik diwariskan secara resesif atau tertutupi oleh alel dominan sehingga tak terekspresikan yang membuat kelainan itu terlambat didiagnosis. Kemudian ada istilah heterozigot yaitu individu yang memiliki fenotif (sifat tampak secara fisik) yang tidak jelas dan mereka diidentifikasi sebagai individu karier (pembawa kelainan) yang akan menurunkan alel resesif (gen dengan kelainan) pada keturunannya dan individu karier adalah individu normal karena ia hanya berperan sebagai pembawa dari gen yang mengandung kelainan, akan tetapi gen itu bersifat resesif karenanya kelainan yang dibawa sulit untuk dilacak. Kelainan itu kelak akan diturunkan pada keturunanya. Kemudian akibat dari sifat kelainan genetik yang tak terdistribusi secara merata, maka pada keturunan dari individu pembawa (karier), kelinan itu dapat muncul sewaktu-waktu. Jadi, peran Hukum Mendel dalam kehidupan manusia adalah untuk mendeteksi probabilitas fenotif spesifik yang dapat memunculkan kelainan dari gen yang diwariskan oleh individu karier. Contohnya adalah untuk mendeteksi probabilitas anak yang menderita buta warna dari kedua orang tua yang memiliki gen buta warna resesif. Dengan mengetahui probabilitas itu, maka dalam perencanaan untuk berkeluarga dan memiliki anak, individu yang berperan sebagai pembawa (karier) dapat menyusun pertimbangan yang matang agar keturunannya tidak memiliki kelainan (gen yang membawa kelainan tidak terekspresikan pada fenotif keturunannya).

            Dewasa ini, Hukum Mendel terus berkembang dan bukan hanya dijadikan sebagai pedoman dalam konsultasi keluarga dan perkawinan seperti penerapan prinsip pendeteksian probabilitas fenotif spesifik, tetapi juga digunakan dalam penelitian tentang tingkat usia seseorang dan penetian tentang mutasi gen yang menghasilkan gen yang kebal terhadap beberapa penyakit kronis. Penelitian yang baru-baru ini dilakukan oleh Giuseppe Passarino, seorang ahli genetika dari Universita ‘della Calabria dan timnya yang melakukan penelitian di wilayah Italia, Ekuador, California, Pensylvania, dan New York terhadap orang-orang yang berusia diatas 100 tahun dan mendekati 100 tahun yang masih memiliki fisik yang bugar dan ingatan yang baik. Dari penelitian itu, Passarino dan timnya berhasil menemukan mutasi gen yang tampaknya mencegah penyakit yang paling sering menimbulkan kematian di usia lanjut. Metode yang digunakan adalah implementasi dari Hukum Mendel dengan menelusuri sejarah keturunan, cangkupan gen, serta analisis terhadap isolasi gen akibat kondisi geografis dan budaya setempat. Hingga akhirnya para peneliti berhasil sampai di akar beberapa keturunan (ras) yang dianggap sebagai ras unggul yang memiliki gen yang mampu mencegah penyakit-penyakit kronis. Berikut adalah hasil penelitiannya:

Tabel 1.1, Hasil Penelitian Giuseppe Passarino dan Timnya (dipublikasikan di Majalah National Geographic edisi Mei 2013 hal. 39)

Gen dengan mutasi	Ras yang memgalami mutasi	Penyakit yang dapat dicegah
CETP & APOC-3	Yahudi Ashkenazi, Keturunan Yahudi Eropa Tengah.	Mencegah tekanan darah tinggi dan menurunkan risiko Alzheimer
GHR, mutasi ini menhalangi hormon pertumbuhan insulin dan menyebabkan kekerdilan	Penderita Sindrom Laron di wilayah Ekuador	Menghambat penyakit diabetes dan kanker
APOC-3	Amish Ordo Lama, anggota ordo yang sangat mengelompok ini diteliti di Lancaster Pennsylvania	Menurunkan kadar kolesterol dalam darah secara drastic
FOXO3a	Orang Amerika keturunan Jepang	Pada kaum pria, mutasi gen ini menurunkan kemungkinan kanker dan penyakit jantung. Gen FOXO ini diduga menjadi faktor utama dari umur panjang.

            Mungkin sekarang banyak yang bertanya-tanya, apakah ada hubungan antara Hukum Mendel dengan Psikologi Pendidikan? Tentu jawabannya ada, hubungan antara Hukum Mendel dengan Psikologi Manusia adalah Hukum Mendel merupakan hukum yang berlaku untuk pewarisan sifat-sifat melalui gen dan dalam gen juga terkandung benih-benih bakat dari individu yang baru terlahir ke dunia sebagai seorang anak. Salah satu tujuan dari pendidikan adalah untuk menumbuh kembangkan pontesi anak didik. Dengan mengetahui konsep dasar dari Hukum Mendel tentang pewarisan sifat, maka diharapkan bahwa para pendidik di sekolah maupun perguruan tinggi mampu memandang setiap peserta didiknya sebagai individu yang memiliki keunikan atau kekhasan tersendiri dan memiliki potensi yang menunggu siraman air dari sungai pengetahuan agar potensi itu bisa tumbuh dan mekar secara maksimal. Dengan demikian, sistem pendidikan yang ideal tentunya dapat terwujud bagi semua anak didik.

(Referensi teori diambil dari resume buku: Mustaqim dan Abdul Wahid. 1991. “Psikologi Pendidikan.” Jakarta: Rineka Cipta resuman oleh Ruby Andriny Mahasiswa FKIP Universitas Muhammadiyah Purwokerto tahun 2010 hal. 7)

“Semangat Memajukan Sistem Pendidikan di Indonesia!”

Microbes Help Children Breathe Easily? Bacteria and Fungi May Offer Protection Against Asthma, Study Suggests

Children who grow up on farms are less likely to suffer from asthma than other rural children. (Credit: iStockphoto/Linda Kloosterhof)

ScienceDaily (Feb. 24, 2011) — Children who grow up on farms are less likely to suffer from asthma than other rural children. An international team of researchers including Dr. Markus Ege and Professor Erika von Mutius at Ludwig-Maximilians-Universitaet (LMU) has published a large-scale study that now indicates that this may be due to differences in the spectrum of microbes the two groups are likely to encounter. This findings suggest that certain microorganisms may protect against the disease.

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The incidence of asthma among children in Europe continues to rise. But not all children are equally at risk. Several studies published over the past few years have shown that children living on farms are significantly less likely to develop asthma than others. An international team of researchers including Dr. Markus Ege and Professor Erika von Mutius of Children's Surgical Clinic in the Dr. von Hauner Children's Hospital (Medical Center of the University of Munich) has just published an epidemiological study that confirms this finding. It shows that the lower susceptibility of farm children to asthma can largely be accounted for by the fact that they are exposed to a greater variety of microorganisms than other children living in the same regions.

The physiological mechanisms underlying the effect remain to be elucidated, but the investigators have identified several species that might be responsible for the reduction in asthma risk. The results have broad implications for the prevention of asthma in other sectors of the population. "We have a long way to go before we can present new preventive measures, but at least we now have candidates for the development of a vaccine," says Ege. (New England Journal of Medicine online, 24 February 2011) Asthma is among the most prevalent chronic illnesses among children in Europe, and in many cases the condition will remain with them all their lives.

This is why asthma presents such a challenge for health-care systems. The disease results from a combination of genetic and environmental factors, and various studies have shown that farm children have a significantly lower risk of developing the condition than other children. In order to identify the reasons for this difference, LMU researchers selected a group of Bavarian schoolchildren for detailed study. In the context of two large-scale, pan-European, epidemiological projects, named GABRIEL and PARSIFAL, Ege and his colleagues compared children living on farms with others from the same rural districts who had little direct contact with farms.

In the new work, the investigators focused on the microbes present in domestic interiors. They collected household dust from children's bedrooms, and analyzed the bacterial and fungal DNAs in the samples. The results showed that farm children must cope with a much greater range of microorganisms than are children who live in other types of environment. The bacteria and fungi seem to act as guardians of health, for it turned out that the more diverse the microbial population, the lower the risk of asthma.

Exactly how the cells and spores perform this trick is still unclear, but the researchers suggest a couple of possible explanations. "One possibility is that a particular combination of microbial species stimulates the innate immune system and so prevents it from entering a state that promotes the development of asthma," says Ege. Another model proposes that continuous exposure to many different microorganisms makes it more difficult for the species that potentially induce asthma to become the dominant forms in the lower respiratory tract -- similarly to the gastrointestinal tract, where a balanced population of microbes is necessary for optimal organ function.

Microbial diversity alone, however, is not enough to prevent asthma. More probably, it takes a particular consortium of species to exert a protective effect. "Within the large spectrum of organisms that we examined, there are some that may be of special interest," reports Ege. "Among these are certain species of bacilli and staphylococci -- Staphylococcus sciuri, for instance -- as well as fungi of the genus Eurotium."

The next challenge facing the team is to elucidate, at the level of single species, the nature of the link between the microorganisms in household dust and the protective effect, with the long-term goal of identifying candidates that might serve as the basis of a live vaccine against asthma. In addition to the LMU researchers, investigators from the Technical University of Munich, the Universities of Besançon (France), Marseille (France), Ulm, Basel (Switzerland), Utrecht (The Netherlands) and Imperial College London (UK) participated in the study. The work was supported by the European Commission (GABRIEL and PARSIFAL) and by the DFG (Deutsche Forschungsgemeinschaft) as part of its Priority Program Transregio 22.

Brown Recluse Spider: Range Could Expand in N. America With Changing Climate

Brown recluse spider. (Credit: iStockphoto/William Howe)

ScienceDaily (Apr. 23, 2011) — One of the most feared spiders in North America is the subject a new study that aims to predict its distribution and how that distribution may be affected by climate changes.

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When provoked, the spider, commonly known as the brown recluse (Loxosceles reclusa), injects powerful venom that can kill the tissues at the site of the bite. This can lead to a painful deep sore and occasional scarring.

But the wounds are not always easy to diagnose. Medical practitioners can confuse the bite with other serious conditions, including Lyme disease and various cancers. The distribution of the spider is poorly understood as well, and medical professionals routinely diagnose brown recluse bites outside of the areas where it is known to exist.

By better characterizing its distribution, and by examining potential new areas of distribution with future climate change scenarios, the medical community and the public can be more informed about this species, said study author Erin Saupe. Saupe is a graduate student in Geology and a Biodiversity Institute student.

To address the issue of brown recluse distribution, Saupe and other researchers used a predictive mapping technique called ecological niche modeling. They applied future climate change scenarios to the spider's known distribution in the Midwest and southern United States. The researchers concluded that the range may expand northward, potentially invading previously unaffected regions. Newly influenced areas may include parts of Nebraska, Minnesota, Wisconsin, Michigan, South Dakota, Ohio, and Pennsylvania.

"These results illustrate a potential negative consequence of climate change on humans and will aid medical professionals in proper bite identification and treatment, potentially reducing bite misdiagnoses," Saupe said.

The paper is published in the March 25 edition of the journal PLoS ONE. The research team included Saupe; Monica Papes, a Biodiversity Institute and Ecology and Evolutionary Biology alumna; Paul Selden, Director of the Paleontological Institute and Gulf-Hedberg Distinguished Professor of Invertebrate Paleontology, Department of Geology; and Richard S. Vetter, University of California-Riverside.

Protein-Patterned Fibers: Researchers Combine Active Proteins With Material Derived from Fruit Fly

Strands of Ubx fiber patterned with fluorescent protein are the result of research by scientists at Rice University and Texas A&M. The strands can contain active proteins that may find use as chemical catalysts and biosensors and in tissue engineering. (Credit: Zhao Huang/Rice University)

ScienceDaily (Apr. 20, 2011) — Researchers at Rice University and Texas A&M have discovered a way to pattern active proteins into bio-friendly fibers. The "eureka" moment came about because somebody forgot to clean up the lab one night.

The new work from the Rice lab of biochemist Kathleen Matthews, in collaboration with former Rice faculty fellow and current Texas A&M assistant professor Sarah Bondos, simplifies the process of making materials with fully functional proteins. Such materials could find extensive use as chemical catalysts and biosensors and in tissue engineering, for starters.

Their paper in the online edition of Advanced Functional Materials details a method to combine proteins with a transcription factor derived from fruit flies and then draw it into fine, strong strands that can be woven into any configuration.

Bondos and Matthews led the team that included primary author Zhao Huang and research technician Taha Salim, both of Rice, and research assistants Autumn Brawley and Jan Patterson, both of Texas A&M.

The research had its genesis while Bondos was in Matthews' Rice lab studying Ultrabithorax (Ubx), a recombinant transcription factor protein found in Drosophila melanogaster (the common fruit fly). This protein regulates the development of wings and legs.

"It's biodegradable, nontoxic and made of naturally occurring proteins -- though we have no reason to believe that fruit flies ever produce enough of these proteins to actually make fibers," Bondos said.

It was a surprise, then, to find that Ubx self-assembles into a film under relatively mild conditions.

"I was cleaning up in the lab one morning and I noticed what appeared to be a drop of water suspended in midair beneath a piece of equipment I was using the previous night," Bondos recalled.

It turned out the droplet was water encased in a sac of Ubx film. The sac was hanging by a Ubx fiber so thin that it was more difficult to see than a strand of a spider's web, Bondos said.

"It clued us in that this was making materials," said Matthews, Rice's Stewart Memorial Professor of Biochemistry and Cell Biology and former dean of the Wiess School of Natural Sciences.

The chance discovery prompted a 2009 paper in the journal Biomacromolecules about the material they dubbed "ultrax," a superstrong and highly elastic natural fiber.

"We found that if you put a little drop of this protein solution on a slide, the Ubx forms a film. And if you touch a needle to that film, you can draw a fiber," Matthews said. "Then we asked, What if we could incorporate other functions into these materials? Can we make chimeras?" The answer was yes, though it took ingenuity to prove.

Chimeras in the biological world contain genetically distinct cells from two or more sources. In Greek mythology, chimeras are beings with parts from multiple animals; a pig with wings, for instance, would qualify. But real chimeras are usually more subtle. On the molecular level, chimeras are proteins that are fused into a single polypeptide and can be purified as a single molecular entity.

As a proof of principle, the team used gene-fusion techniques to create chimeras by combining Ubx with fluorescent and luminescent proteins to see if they remained functional. They did. The combined materials still formed a film on water. Drawn into fibers and put under a microscope, Ubx combined with enhanced green fluorescent protein (EGFP) kept its bright green color. Ubx-mCherry was bright red, the brown protein myoglobin (from sperm whales) was brown, and luciferase glowed.

Huang was able to make patterns with strands generated by the chimeras by twisting red and green fluorescent proteins into candy cane-like tubes, or lacing them on a frame. "This patterning technique is pretty unique and very simple," said Huang, who recently defended his thesis on the subject. He said making solid materials with functional proteins often requires harsh chemical or physical processing that damages the proteins' effectiveness. But creating complex three-dimensional structures with Ubx is efficient and requires no specialized equipment.

Bondos is studying how many proteins are amenable to fusion with Ubx. "It looks like it's a fairly wide range, and even though Ubx is positively charged, both positively and negatively charged proteins can be incorporated." She said even proteins that don't directly fuse with Ubx may be able to connect through intermediary binding partners.

Bondos said the 2009 paper "showed we could make three-dimensional scaffolds. We can basically make rods and sheets and meld them together; anything you can build with Legos, we can build with Ubx."

Ubx-based materials can match the natural properties of elastin, the protein that makes skin and other tissues pliable, Bondos said. "You don't want to make a heart out of something hard, and you don't want to make a bone out of something soft," she said. "We can tune the mechanical properties by changing the diameter of the fibers."

She said functionalized Ubx offers a path to growing three-dimensional organs layer by layer. "We should be able to build something shaped like a heart, and because we can pattern the chimeras within fibers and films, we can build instructions into the material that cause cells to differentiate as muscle, nerves, vasculature and other things."

Bondos suggested the material might also be useful for replacing damaged nerves. "We should be able to stimulate cell attachment and nerve growth along the middle and factors on the ends to enhance attachment to existing nerve cells, to tie it into the patient. It really is pretty exciting."

Matthews said the ability to characterize and pattern fibers for different functions should find many uses, because enzymes, antibodies, growth factors and peptide recognition sequences can now be incorporated into biomaterials. She said sequential arrays of functional fibers for step-by-step catalysis of materials is also possible.

"You're only limited by your mechanical imagination," she said.

The Robert A. Welch Foundation and Texas A&M Health Science Center Research Development and Enhancement Awards Program supported the research.

"Nipah Virus" Strikes Again

Breaking the Chain in Bangladesh

Nipah virus claims few lives, but in Bangladesh, where nearly all known cases in the past decade have occurred, the virus kills almost three-quarters of those it infects and leaves many survivors with crippling neurological disorders. Almost every winter since 2001, the virus has flared up in Bangladesh and has killed 111 people in the past decade; 50 people died in 2004, the worst year. This winter is shaping up to be bad, with the death toll at 27 as Science went to press—and 2 months to go in the Nipah season. Disease hunters believe they have pinned down the virus's natural reservoir—fruit bats—and they have nailed a transmission route in Bangladesh: consumption of contaminated date palm sap. But fruit bats test positive for Nipah antibodies across southern Asia, and date palm sap is a delicacy throughout Bangladesh. Yet the virus mostly haunts only what investigators call "the Nipah belt," a clutch of districts near the Ganges River in western Bangladesh.

(Source:Sciecemag)