May 14, 2016

A hole in the heart

We always talk about conditions affecting the heart later in life such as hypertension, coronary heart disease and heart failure. We don't talk much of any conditions of the heart which are present at birth, known as congenital heart disease or defects. Congenital heart disease, also abbreviated to CHD and not to be confused with coronary heart disease, is a type of defect or malformation in one or more structures of the heart or blood vessels that occurs before birth. These defects happen as the foetus is developing. CHD is more common than one thinks, occurring around 8 to 10 out of every 1,000 births. The cause is unknown in the majority of cases although certain conditions or factors can predispose a child to being born with CHD. They include genetic or chromosomal abnormalities in the child such as Down's Syndrome, viral infections in the mother during pregnancy such Rubella, and consumption of certain drugs or alcohol by the mother during pregnancy. There are many different types of CHD and they range from a mild form that can go undetected until much later in life to the very severe where the baby is cyanosed - bluish discolouration of the lips and face because of lack of oxygen in the blood - within days of being born. Let us just limit the discussion here to atrial and ventricular septal defects, known as ASD and VSD respectively. In layman's term, they are also known as hole-in-the-heart. You all knoe that the heart is divided into four chambers - two on the left where blood rich in oxygen from the lungs passes through to get to the body - and two on the right where blood lacking in oxygen returning from the body goes to before it gets back to the lungs. It is vital that the wall separating the two sides called the septum is intact. Any breach in the wall will mean that blood with different oxygen concentrations are mixed together. ASD is when the breach is in the septum between the two atria and likewise, VSD denotes a defect in the ventricular septum. This may not be a big problem in the beginning as the left chambers which have a higher pressure system than the right will direct blood to the right chambers via the hole or defect in the wall. However, as the pressure rises in the right chambers through the years because of constant flow of high pressure from the left, it can damage the lung causing pulmonary hypertension. When it comes to a point where both sides have the same blood pressure level, there is then a free mixing of high and low oxygenated blood on both sides resulting in body tissues being compromised of good oxygenation. The person will be cyanosed and breathless and may also have symptoms of heart failure. Of course, that is the extreme end of the spectrum. For most with ASD or VSD, they are fairly asymptomatic and the condition only gets discovered during a routine medical examination when a murmur - a characteristic sound heard by using a stethoscope placed on the chest over the heart - is detected. The definitive test is an echocardiogram which is an ultrasound scan test of the heart. When the septal defect is small the doctor will usually advise the person concerned to come back for a checkup every year or so. No regular medication is needed. He will be advised to take antibiotics as a preventative measure against bacterial infection affecting the heart (endocarditis) if he is going to have a dental procedure or any procedure that may cause bleeding. If the defect is big from the echocardiogram, then an interventional procedure or surgery to close the hole has to be considered. If you are a parent and you notice the following in your child - cyanosis of the skin, lips and fingernails, poor weight gain, fast breathing, recurrent lung infections and inability to exercise well, it is suggested that you bring your child to the attention of your doctor or paediatrician. There is a possibility that he or she has a congenital heart disease.

Getting along with your teachers

Your Maths teacher wears clothes from 1982 and always mispronounces your name. Your English teacher loves to start classes with pop quizzes. It can be hard to think of these givers of grades as real people. But they eat nasi lemak, drink teh tarik, watch movies, and enjoy sports on the weekends, just like you. So how can you get along with your teachers? Here are some tips. Why Work on Good Relationships With Teachers? A good relationship with a teacher today may help you in the future. You will need teachers' written recommendations to apply to a college or for a job after school. And if you're thinking about going into a career in science, who better to ask about the field than your science teacher? Teachers are often plugged into the community and may be the first to find out about local competitions, activities, or contests. They also may know about scholarships. Teachers are another group of adults in your life who can look out for you, guide you, and provide you with an adult perspective. Many are willing to answer questions, offer advice, and help with personal problems. Developing Good Teacher-Student Relationships We all have our favourite teachers — those who seem truly interested and treat us as intelligent beings. But what about teachers we don't know as well (or even don't like much)? You can do lots of things to get a good connection going with your teacher. First, do the obvious stuff: show up for class on time, with all assignments completed. Be alert, be respectful, and ask questions. Show an interest in the subject. Obviously, your teachers are really interested in their subjects or they wouldn't have decided to teach them! Showing the teacher that you care — even if you're not a math whiz or fluent in English — sends the message that you are a dedicated student. You can also schedule a private conference during a teacher's free period. Use this time to get extra help, ask questions, inquire about a career in the subject, or talk about your progress in class. You may be surprised to learn that your teacher is a bit more relaxed one-on-one than when lecturing in front of the whole class. It is possible to try too hard, though. Here are some things to avoid when trying to establish a relationship with your teacher: Not being sincere. Teachers sense when your only motivation is to get special treatment, a college reference, or a recommendation. Trying to be teacher's pet. Your behaviour will come off as phony and your classmates may start to resent you. Giving extravagant gifts. It's OK to offer a small token of appreciation to teachers if they've been helpful to you. But flashy, expensive items could send the wrong message, and a teacher is usually not allowed to accept anything expensive. Common Teacher-Student Problems If you're having problems with a teacher, try to figure out why. Do you dislike the subject? Or do you like the subject but just can't warm up to the teacher? If you don't like the subject being taught, it can affect your relationship with the teacher. Some students say it helps them to think of classes that seem like chores as stepping stones toward a bigger goal, like getting a diploma or going on to college. That allows them to keep the class in perspective. Other students say they try to find the practical value in classes they don't like. You may hate maths, but learning how to calculate averages and percentages can help you in everything from sports to leaving a tip. If you find a subject hard, talk to your teacher or a parent about extra tutoring. If you find it boring, talk to your teacher (or another favourite teacher, friend, or parent) about ways to see the subject in a different light. Mat constantly fell asleep in his sophomore history class because the past seemed so removed from reality. But things changed when he mentioned his struggle over a project to his homeroom teacher. The teacher talked to Mat and found out that his great-grandfather had fought with the communist. The teacher suggested Mat uses his great-grandfather's letters in his project. Not only did Mat get an A, he also learned a lot about a family member he barely remembered from childhood. What if you just don't like the teacher? When it comes to working with teachers, personality can come into play just as it can in any relationship. People naturally just get along better with some people than with others — it's impossible to like everyone all the time. Learning to work with people you don't connect with easily is a good skill to have in life, no matter what your goals are. If you feel at odds with your teacher, pick your battles carefully. Questioning a grade or asking to retake a test once is fine. But second-guessing a teacher's judgment on your grades all the time may annoy him or her. Constantly squabbling over a few points on every test can cause friction in your relationship. Common courtesy and respect are basic requirements of any relationship. Just as teachers need to be fair and treat everyone equally, students have responsibilities too. You don't have to like your teacher or agree with what he or she says, but it is necessary to be polite. If you need to be out of school for medical or other reasons, let your teacher know. And it's your responsibility to make up the work from missed classes. Don't expect your teacher to hunt you down or take class time to fill you in. Just like personal problems can sometimes slow you down, the same is true for your teachers. Job stress, family issues, or health problems are all factors that can affect a teacher's performance, leaving him or her cranky, irritable, or unable to concentrate. Keep in mind that too much disciplinary action can show up on a student's permanent record. This means that when someone asks for your school record, they can see the things you did — even if they happened years ago. What to Do if You Don't Get Along Before you try to get out of a class to escape a teacher you don't like, here are a few things you can try to make a difficult relationship work: Meet with the teacher and try to communicate what you're feeling. Tell him or her what's on your mind, using statements such as, "It embarrasses me in class when I feel like my intelligence is being put down" or "I can't learn in class when I feel like only a few people ever get called on to participate." See if you can work it out between the two of you. Ask yourself, "What can I learn from this teacher?" Even if you don't worship his or her personality or lectures, dig deep until you find a subject in which your teacher is very knowledgeable. Focus on that part of the teacher's personality, and use it as a tool for learning. Not only will you gain more knowledge in that subject, but a closer relationship with your teacher may help you understand one another better. Talk to students who are doing well in the class and ask them for tips, tools, and a plan of action to get along with the teacher better. Sometimes having a second set of notes can be helpful, so asking a classmate who is willing to share them with you is a great idea. If you're too shy to talk to other students, study their actions and behaviour in the classroom and try to follow that lead. If you still can't get along, make an appointment with the school counselor, who can offer many tips and suggestions for getting more out of difficult teacher relationships. Sometimes a counselor can act as a mediator between you and the teacher. Teachers are there for more than just homework, and they know about more than just their subject matter. They can help you learn how to function as an adult and a lifelong learner. Undoubtedly, there will be a few teachers along the way who you'll always remember — and who might change your life forever.

Nov 21, 2014


Jun 30, 2014

Peperiksaan Pusat Amali Sains untuk subjek Physics, Chemistry, Biology dan Additional Science SPM 2015

Biology Workshop Paper 2 and Paper 3 (SM Sains Kubang Pasu)

Jun 17, 2014

Jaundice among newborns

Jaundice refers to the yellow colour of the skin and whites of the eyes caused by excess bilirubin in the blood. Bilirubin is produced by the normal breakdown of red blood cells.

Normally, bilirubin passes through the liver and is excreted as bile through the intestines. Jaundice occurs when bilirubin builds up faster than a newborn's liver can break it down and pass it from the body. Reasons for this include:
  Newborns make more bilirubin than adults do since they have more turnover of red blood cells. 
  A newborn baby's still-developing liver may not yet be able to remove adequate bilirubin from the blood. 
  Too large an amount of bilirubin is reabsorbed from the intestines before the baby gets rid of it in the stool. 

High levels of bilirubin — usually above 25 mg — can cause deafness, cerebral palsy, or other forms of brain damage in some babies. In less common cases, jaundice may indicate the presence of another condition, such as an infection or a thyroid problem. The American Academy of Pediatrics (AAP) recommends that all infants should be examined for jaundice within a few days of birth.

Types of Jaundice
The most common types of jaundice are:
Physiological (normal) jaundice: occurring in most newborns, this mild jaundice is due to the immaturity of the baby's liver, which leads to a slow processing of bilirubin. It generally appears at 2 to 4 days of age and disappears by 1 to 2 weeks of age.
Jaundice of prematurity: occurs frequently in premature babies since they are even less ready to excrete bilirubin effectively. Jaundice in premature babies needs to be treated at a lower bilirubin level than in full term babies in order to avoid complications.
Breastfeeding jaundice: jaundice can occur when a breastfeeding baby is not getting enough breast milk because of difficulty with breastfeeding or because the mother's milk isn’t in yet. This is not caused by a problem with the breast milk itself, but by the baby not getting enough to drink.
Breast milk jaundice: in 1% to 2% of breastfed babies, jaundice may be caused by substances produced in their mother's breast milk that can cause the bilirubin level to rise. These can prevent the excretion of bilirubin through the intestines. It starts after the first 3 to 5 days and slowly improves over 3 to 12 weeks.

In mild or moderate levels of jaundice, by 1 to 2 weeks of age the baby will take care of the excess bilirubin on its own. For high levels of jaundice, phototherapy — treatment with a special light that helps rid the body of the bilirubin by altering it or making it easier for your baby's liver to get rid of it — may be used.

More frequent feedings of breast milk or supplementing with formula to help infants pass the bilirubin in their stools may also be recommended. In rare cases, a blood exchange may be required to give a baby fresh blood and remove the bilirubin.

If your baby develops jaundice that seems to be from breast milk, your doctor may ask you to temporarily stop breastfeeding. During this time, you can pump your breasts so you can keep producing breast milk and you can start nursing again once the condition has cleared.

If the amount of bilirubin is high, your baby may be readmitted to the hospital for treatment. Once the bilirubin level drops and the treatment is stopped, it is unlikely that treatment for jaundice will need to be restarted.

Blood group incompatibility (Rh or ABO problems): if a baby has a different blood type than the mother, the mother might produce antibodies that destroy the infant's red blood cells. This creates a sudden buildup of bilirubin in the baby's blood. Incompatibility jaundice can begin as early as the first day of life. Rh problems once caused the most severe form of jaundice, but now can be prevented with an injection of Rh immune globulin to the mother within 72 hours after delivery, which prevents her from forming antibodies that might endanger any subsequent babies.

Symptoms and Diagnosis
Jaundice usually appears around the second or third day of life. It begins at the head and progresses downward. A jaundiced baby's skin will usually appear yellow first on the face, followed by the chest and stomach, and finally, the legs. It can also cause the whites of an infant's eyes to appear yellow.

Since many babies are now released from the hospital at 1 or 2 days of life, it is best for the baby to be seen by a doctor within 1 to 2 days of leaving the hospital to check for jaundice. Parents should also keep an eye on their infants to detect jaundice.

If you notice your baby’s skin or eyes looking yellow you should contact your child's doctor to see if significant jaundice is present.

At the doctor's office, a small sample of your infant's blood can be tested to measure the bilirubin level. Some offices use a light meter to get an approximate measurement, and then if it is high, check a blood sample. The seriousness of the jaundice will vary based on how many hours old your child is and the presence of other medical conditions.

Feb 25, 2014

Biological Terms

One of the keys to being successful in biology is being able to understand the terminology. Difficult biology words and terms can be made easy to understand by becoming familiar with common prefixes and suffixes used in biology. These affixes, derived from Latin and Greek roots, form the basis for many difficult biology words.
Below is a list of a few biology words and terms that many biology students find difficult to understand. By breaking these words down into discrete units, even the most complex terms can be understood. 
1. Autotroph
This word can be separated as follows: Auto - troph.
Auto - means self, troph - means nourish. Autotrophs are organisms capable of self nourishment.
2. Cytokinesis
This word can be separated as follows: Cyto - kinesis.
Cyto - means cell, kinesis - means movement. Cytokinesis refers to the movement of the cytoplasm that produces distinct daughter cells during cell division.
3. Eukaryote
This word can be separated as follows: Eu - karyo - te.
Eu - means true, karyo - means nucleus. A eukaryote is an organism whose cells contain a "true" membrane bound nucleus.
4. Heterozygous
This word can be separated as follows: Hetero - zyg - ous.
Hetero - means different, zyg - means yolk or union, ous - means characterized by or full of. Heterozygous refers to a union characterized by the joining of two different alleles for a given trait.
5. Hydrophilic
This word can be separated as follows: Hydro - philic.
Hydro - refers to water, philic - means love. Hydrophilic means water-loving.
6. Oligosaccharide
This word can be separated as follows: Oligo - saccharide.
Oligo - means few or little, saccharide - means sugar. An oligosaccharide is a carbohydrate that contains a small number of component sugars.
7. Osteoblast
This word can be separated as follows: Osteo - blast.
Osteo - means bone, blast - means bud or germ (early form of an organism). An osteoblast is a cell from which bone is derived.
8. Tegmentum
This word can be separated as follows: Teg - ment - um.
Teg - means cover, ment - refers to mind or brain. The tegmentum is the bundle of fibers that cover the brain.
Yes, this is an actual word. What does it mean? Biology can be filled with words that sometimes seem incomprehensible. By "dissecting" these words into discrete units, even the most complex terms can be understood. To demonstrate this concept, let's begin by performing biology word dissections on the word above.
To perform our biology word dissection, we'll need to proceed carefully. First, we come to the prefix (pneu-), or (pneumo-) which means lung. Next, is ultra, meaning extreme, and microscopic, meaning small. Now we come to (silico-), which refers to silicon, and (volcano-) which refers to the mineral particles that make up a volcano. Then we have (coni-), a derivative of the Greek word konis meaning dust. Finally, we have the suffix (-osis) which means affected with. Now lets rebuild what we have dissected:
Considering the prefix (pneumo-) and the suffix (-osis), we can determine that the lungs are affected with something. But what? Breaking down the rest of the terms we get extremely small (ultramicroscopic) silicon (silico-) and volcanic (volcano-) dust (coni-) particles. Thus, pneumonoultramicroscopicsilicovolcanoconiosis is a disease of the lungs resulting from the inhalation of very fine silicate or quartz dust. That wasn't so difficult, now was it?
Now that we've honed our dissection skills, let's try some frequently used biology terms. For instance:
(Arth-) refers to joints and (-itis) means inflammation. Arthritis is the inflammation of a joint(s).
(Erythro-) means red and (-cyte) means cell. Erythrocytes are red blood cells.
Okay, let's move on to more difficult words. For instance:
Dissecting, we have (electro-), pertaining to electricity, (encephal-) meaning brain, and (-gram) meaning record. Together we have an electric brain record or EEG. Thus, we have a record of brain wave activity using electrical contacts.
Individuals with this disorder suffer from delusions and hallucinations. (Schis-) means split and (phren-) means mind.
These are ancient bacteria that live in extremely hot and acidic environments. (Therm-) means heat, next you have (-acid), and finally (phil-) means love. Together we have heat and acid lovers.
Once you understand the commonly used prefixes and suffixes, obtuse words are a piece of cake! Now that you know how to apply the word dissection technique, I'm sure you'll be able to determine the meaning of the word thigmotropism (thigmo - tropism).