Feathers (Bulu)



Feather evolution










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Nail structure (Struktur kuku)



Integumentary system (Sistem kulit)

Structure and Functions of Integumentary system…


Taring ular berbisa

Biasanya ular berbisa mempunyai taring yang tajam yang digunakan sebagai senjata untuk memasukkan bisa ke dalam tisu mangsanya. Taring dikatakan berasal atau berkembang daripada gigi.

Artikel di bawah ini memuatkan informasi tentang taring ular berbisa dan struktur yang berkaitan dengannya.

Fangs Venomous snakes

The fangs of venomous snakes, which evolved from teeth, are among “the most advanced bioweapon systems in the natural world,” says Freek Vonk of Leiden University in the Netherlands. “There is not a comparable structure as advanced, as sophisticated, as for example a rattlesnake fang and venom gland.”

Source

Bagaimanakah perkembangan taring ular??

How Snakes Got Their Fangs

By Jeanna Bryner, Senior Writer
30 July 2008

Biologists have sunk their teeth into the question of snake fang development, revealing how these poison prickers have evolved from regular teeth and allowed snakes to become such champion biters.

The research suggests that both rear and front fangs in venomous snakes developed from separate teeth-forming tissue at the rear of the mouth — unlike the situation for non-venomous snake dentition and human teeth. This finding, detailed in the July 31 issue of the journal Nature, could explain why snakes flourished beginning some 60 million years ago, geologically soon after non-avian dinosaurs went extinct.

“The snake venom system is one of the most advanced bioweapon systems in the natural world,” said lead researcher Freek Vonk of Leiden University in the Netherlands. “There is not a comparable structure as advanced, as sophisticated, as for example a rattlesnake fang and venom gland.”

Fang factors

Snake fangs are sharp, enlarged teeth positioned along the upper jaw at the front or rear of a snake’s mouth and connected to venom glands. Only the venomous snakes, which are considered advanced snakes, sport such fangs, while the non-venomous snakes like pythons are equipped with only the normal rows of teeth.

The Asian vine snake (Aheatulla prasina) sports rear fangs. The enlarged teeth in front of the jaw are not fangs, but teeth used for grabbing their prey, which are fast lizards. Credit: © Freek Vonk.

And sometimes even a venomous snake will impart a “dry” bite, not delivering the potent venom.

Most venomous snakes, including grass snakes, have fangs positioned in the rear of the mouth, while a few groups, including rattlesnakes, cobras and vipers, have fangs jutting down from their upper jaws in the front of the mouth.

“If you want to eat a very dangerous prey, like a big rat with razor-sharp rat teeth, then it would be more advantageous to have your fangs in front of the mouth so you can just bite it quickly and then let go,” Vonk told LiveScience, “instead of biting it and holding on and then chewing the venom into the tissue, because then the rat can bite back.

Fang development

To figure out how both types of snake fangs evolved from non-fanged species, Vonk and his colleagues looked at fang development in 96 embryos from eight living snake species. Here are their names:

Non-venomous snakes:

* Water python (Liasis mackloti)

Venomous front-fanged snakes:

* Indonesia pit viper or Hageni’s treeviper (Trimeresurus hageni)
* Rhombic Night Adder (Causus rhombeatus)
* Malayan pit viper (Calloselasma rhodostoma)
* Asian spitting cobra (Naja siamensis)
* Cape Coral Snake (Aspidelaps lubricus infuscatus)

Rear-fanged venomous snakes:

* Rat snake (Elaphe obsolete)
* Grass snake (Natrix natrix)

The team’s analyses showed that the front and rear fangs develop from a separate teeth-forming tissue at the back of the upper jaw. For all front-fanged venomous snake species, the front fangs displaced forward during embryo development by rapid growth of the embryonic upper jaws. The rear fangs stayed put where they formed.

That’s unlike the dental development scenario for humans and non-venomous snakes, such as pythons. As an embryo, all of our teeth in the upper jaw sprout from one tooth-forming tissue, while all the bottom teeth develop from another tooth-forming tissue.

“The uncoupled rear part of the teeth-forming tissue evolved in close association with the venom gland, thereafter forming the fang-gland complex,” Vonk said. “The uncoupling allowed this to happen, because the rear part of the teeth-forming tissue did not have constraints anymore from the front part.”

Super snakes

The separate development of the rear part of the tissue, Vonk said, may have played a major role in snakes’ ability to diverge into the 3,000 species found throughout the world today.

“It sheds light on one of those nagging questions in herpetology — how did a diversity of fang types among snakes evolve?” said David Kizirian, a herpetologist at the American Museum of Natural History in New York who was not involved in the study.

The research was funded by the Netherlands Organization for Scientific Research, Dutch government, Dutch Technology Foundation, Curatoren fund, LUSTRA fund, Australian Research Council, Australian Academy of Science, Whitman College and Leiden University Fund.

Source

Rawatan kelemumur

Banyak orang menghadapi masalah kelemumur, tapi tahapnya berbeza-beza kerana lain orang lain kadar terjadinya kelemumur di atas kulit kepala. Pada mereka yang mempunyai masalah kulit kepala yang kering, kelemumur memang banyak, kerana lapisan korneum pada kulit kepala berganti dengan cepat dan menghasilkan kelemumur yang banyak.

Berikut ada beberapa saranan untuk merawat kelemumur dengan menggunakan beberapa jenis shampoo yang sesuai….

Understanding Dandruff — Treatment

Reviewed by Norman Levine, MD

What Are the Treatments for Dandruff?

Mild cases of dandruff may need nothing more than shampooing more frequently. Daily cleansing with a dandruff shampoo to decrease oil and cell buildup can keep moderate dandruff in check, but consult your doctor about more stubborn forms such as seborrheic dermatitis.

Not all dandruff shampoos are alike, so you may need to experiment with them to find the one that works best for you. Here are some examples of some effective over-the-counter shampoos you can try.

* Coal-tar preparations (Neutrogena T/Gel, Tegrin)

* Pyrithione zinc (Suave Dandruff Control, Pert Plus Dandruff Control, Head & Shoulders)

* Salicylic acid and sulfur (T-Sal, lonil T, Sebulex)

* Selenium sulfide (Selsun Blue)

* Ketoconazole (Nizoral A-D) available as a 1% over-the-counter shampoo and a 2% prescription-strength shampoo.

You may need to alternate between types of shampoos if one type initially controls the dandruff but later loses its effectiveness. If you find that you are still scratching and shedding after trying over-the-counter preparations, see your doctor. You may be using the wrong shampoo for your condition. For really stubborn dandruff cases you may need to use a prescription lotion or shampoo.

Most doctors recommend that dandruff sufferers use a medicated shampoo daily, rubbing your scalp well and leaving the lather on for at least five minutes. Be sure to rinse thoroughly; shampoo and soap residue can actually aggravate skin problems. Brush your hair from your scalp outward with steady, firm strokes. This will carry oil from your scalp, where it can cause dandruff, along the hair strands, which need the oil to stay shiny and healthy.

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Cara mengatasi warna hitam dan bengkak di bawah mata

Di antara tanda-tanda proses penuaan ialah warna hitam bulat dan bengkak di bawah mata. Jika tidak dijaga, tanda-tanda ini akan cepat muncul sebelum tiba masanya.

Banyak terdapat pelbagai iklan anti-penuaan yang mendakwa dapat mengubati tanda-tanda ini dengan pelbagai jenis krim dan alat solek yang lain. Rawatan dalaman dengan mengenalpasti dan seterusnya menghindari faktor penyebabnya adalah lebih berkesan daripada rawatan luaran semata-mata.

Artikel berikut memfokuskan kepada cara menyelesaikan masalah warna hitam dan bengkak di bawah mata dengan kaedah menjaga kulit secara semulajadi dan menghindari faktor penyebab kepada gejala tersebut….

Solutions for Dark Circles and Puffy eyes

By Wendy C. Fries
Reviewed By Louise Chang, MD

Do you have puffy eyes or under-eye circles? Whether the cause is a few long days or too many restless nights, you’ve probably dealt with both at one time or another.

If your solution is to splash a little cold water on your face or grab a concealer, stop right there. There’s more that you can do to unpack those under-eye bags and prevent eye puffiness. These simple tips from skin care pros can get you started.

What Causes Dark Under-Eye Circles

Dark circles, or bags under your eyes, have many causes. These include:

* Increased melanin (also called hyperpigmentation)
* Fat loss beneath the eye
* Broken blood vessels

Hard living — too much caffeine and tobacco and too little sleep — is a less common cause of eye puffiness and bags.

6 Solutions for Under-Eye Circles and Bags

Try these tips for brightening your baby blues or bodacious browns:

* Get enough sleep. Sound sleeping is an inexpensive, easy way to help minimize dark under-eye circles, no matter what the cause. Sleep not only helps keep eyes bright. It also aids your body in repairing cell damage to your skin.

* Avoid alcohol and caffeine. Though they may perk you up in the short term, caffeine and alcohol don’t do the same for your skin. They can cause mild dehydration, making dark circles more obvious.

* Consider skin lighteners or bleaching agents. If the dark circles under your eyes are due to too much melanin, creams containing lightening agents such as retinol, hydroquinone, kojic acid, green tea, vitamin C, or soy can be helpful, according to California dermatologist Sonia Badreshia-Bansal, MD. To help skin-lightening products work their best, avoid the sun and use sunscreen daily. Badreshia-Bansal suggests a sunscreen with zinc and a sun-protection factor (SPF) of 30.

* Check out injectable fillers. A dermatologist may administer these if your dark eye circles are due broken blood vessels, says Badreshia-Bansal. Fillers can also help if fat loss is the cause of bags under the eyes.

* Look into laser treatments and vitamin K. Laser treatmentsmay reduce the look of dark circles due to broken blood vessels. Skin care products containing vitamin K can also help.

* Go a shade lighter in your concealer. A concealer one shade lighter than your skin tone can help disguise under-eye circles. A concealer with an SPF of 15 or higher provides double benefits. If your skin tends to be oily or acne-prone, use an oil-free concealer.

6 Strategies to Prevent Eye Puffiness

Lots of things can lead to puffy eyes — from too much to too little sleep, from eating poorly to getting older. To help reduce the look of eye puffiness, the pros offer these suggestions:

* Sleep. It’s as important to preventing puffy eyes as it is to diminishing dark circles. Start by getting at least eight hours of good sleep a night.

* Drink. Staying well-hydrated can help prevent puffy eyes, says Chicago dermatologist Carolyn Jacob, MD. Drinking plenty of healthy liquids, especially water, helps keep overall skin tone firm and full looking.

* Cut back on salt. Retaining body fluid can cause puffy, doughy looking skin. Reducing salt intake helps reduce the tendency to retain excess water. An easy way to cut back on salt? Reduce the processed foods in your diet.

* Use cool compresses. Florida dermatologist Andrea Cambio, MD, advocates the de-puffing power of chilled, moist green tea bags. Elizabeth L. Tanzi, MD, a Washington, DC dermatologist, suggests gently placing cool cucumber slices or a bag of frozen peas or carrots on the eyes for 10 to 15 minutes. A gel eye-mask will also do the trick.

* Consider fillers. These can help if collagen and elastin break down — “causing surrounding skin to pooch out,” in the words of dermatologist Fredric Brandt, MD, in his book 10 Minutes, 10 Years. Fillers can actually make puffiness look smaller.

* Learn to accept the look of your eyes. Some people are just more prone to puffy eyes or dark eye circles, according Brandt. As we grow older, skin naturally weakens and becomes less resilient, so puffy eyes or dark circles naturally become more noticeable.

These tips may help you keep your eyes looking their best. But the most effective eye-brightening tip may also be the easiest one to implement: Smile!

Source

Apa itu Kolagen?

Kolagen adalah protein utama pada tisu penghubung dalam mamalia dan merupakan salah satu protein yang panjang di samping struktur fibrous protein yang berbeza daripada protein globul (enzim). Terdapat lebih daripada 25 jenis kolagen wujud dalam badan secara semulajadi.

Kolagen memainkan peranannya dalam kesihatan penjagaan kulit, otot, tulang, rawan, urat, rambut, kuku dan gigi. Rantaian kolagen yang kuat yang juga dikenali sebagai fiber kolagen merupakan komponen utama pada matrik ekstraselular yang mengukuhkan tisu serta struktur sel. Kolagen merupakan komponen utama dan fascia, cartilage, ligamen, tendon tulang serta kulit. Dengan adanya lapisan keratin yang lembut, ia membantu dalam menguatkan struktur lapisan kulit di samping elastisiti kulit. Selain itu, kolagen juga membantu dalam menguatkan saluran darah serta memainkan peranannya dalam membentuk tisu tubuh.

Secara semulajadi, ia memerangkap kelembapan dan untuk keanjalan kulit.

Seringkali kolagen dikaitkan dengan kesihatan kulit manusia. Ia bersama-sama keratin menjadikan kulit kuat dan anjal. Kolagen menjadi kurang dengan bertambahnya usia. Kulit menjadi berkedut. Oleh itu, tidak hairanlah sekiranya ramai yang mencari-cari sumber dalam usaha menangani kesan ketara penuaan pada kulit. Selain itu, kolagen diperlukan dalam hal perubatan, turut dijual sebagai suplemen bagi melancarkan pergerakan sendi. Kadang-kadang digunakan dalam merawat dan mengubat kes-kes melecur yang serius. Bagi merawat kes melecur, ia digunakan bagi mencipta ganti kulit palsu.

Salah satu fungsi kolagen adalah merawat luka pada kulit. Ia merangsang platelet darah agar cepat membeku dan membentuk selapisan bagi melindungi luka.

Tahukah anda dari mana sumber kolagen dalam suplemen yang ada di pasaran??

1) Daripada bovine (lembu) – diternak secara tertutup contohnya di Australia dan New Zealand
2) Daripada babi (porcine origin)
3) Daripada haiwan laut – contohnya ikan dan gamat
4) Daripada tumbuhan – contohnya kacang soya
5) Daripada Yak – produk dari China
6) Daripada manusia – plasenta, janin yang digugurkan dan ada cerita dari banduan yang ditembak mati!

Oleh itu, pastikan kolagen yang anda makan/gunakan itu dari sumber yang halal. Kalau tidak pasti, sila tanya ahli farmasi yang bertugas, tentu mereka bersedia membantu (kalau mereka ikhlas).

Hati-hati! Terdapat produk kolagen yang tidak dapat dipastikan sumbernya dengan jelas dan produk ini adalah diragui. Walau bagaimanapun, jika produk kolagen tersebut jelas berasal daripada `Seafood’ atau gamat atau tumbuhan, memang tidak diragukan halalnya. Kalau sumber selain daripada itu perlulah diselidiki sebelum dibeli/dimakan/digunakan kerana sumber kolagen yang paling mudah diperolehi adalah daripada kulit babi atau gamat.

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