Smooth Muscle cells by Polarlys

The human body has three different kinds of muscle: smooth, skeletal and cardiac. Smooth muscle is the involuntary, non striated muscle that is found in your digestive tract, blood vessels, lymph system, bladder, respiratory system, uterus, skin – almost any part of the body you can think of that requires movement of some type that is automatically regulated without your conscious control. For example, smooth muscle lines your digestive tract and is responsible for moving the partially digested food through the small and large intestine by peristalsis, the systematic contraction and relaxation of muscle fibers that produces a squeezing effect. Peristalsis is what happens when you swallow food as well. Smooth muscle cells contain only one nucleus; whereas skeletal muscle cells contain multiple nuclei.

Skeletal muscle is under our conscious control and is involved in every movement the human body

Skeletal muscle structure by Raul654

makes; be it walking, talking, chewing, riding a bike, and so on. Skeletal muscle fibers are structurally different from smooth muscle in that they are striated – under a microscope, dark lines appear along their length. Each space between two striations in a skeletal muscle cell is called a sarcomere and is made up of actin and myosin proteins. When a muscle contracts or relaxes, actin and myosin fibers slide against one another becoming closer together or further apart. Thus the striations appear (if we could see this in action under a microscope) to come closer together or further apart.

Individual smooth muscle cells are fusiform in shape and flatten out in their relaxed state and fatten up in their contracted state. Individually, these cells have more elasticity than skeletal muscle cells.

Heart Muscle fibers by Dr.S. Girod, Anton Becker

Cardiac muscle cells are striated, involuntary cells found in the heart. They differ from skeletal and smooth muscle in many ways, but two are key: cardiac muscle fibers appear branched under the microscope, but still have a striated appearance and the chemical mechanisms that activate their contraction or relaxation are different from those of skeletal or smooth muscle.

Crab Nebula taken by the Hubble Telescope

For two words so similar, they could hardly be more different in meaning. Astronomy is the study of celestial objects; in short, objects outside the Earth’s atmosphere. Astrology is a philosophy that teaches that placement of celestial objects – the sun, moon and stars determines and influences your personality. Astronomy is a science whereas Astrology is is a pseudoscience.  Historically, the two disciplines were related but parted ways in the 17th century when core scientific principles such as the Earth revolves around the Sun which is the centre of the solar system became widely accepted as fact.

Put in another way; Astronomy is the study of celestial objects and Astrology is the study of how the position of said celestial objects affects mood, personality and world events. Astrology is not empirically provable. There is no evidence that the predictions made by Astrology are true and many followers of Astrology suffer from Confirmation Bias – that is, they tend to believe outcomes that support their preconceptions: cherry picking the evidence as it were. Simply put, they believe that Astrology is true and confirm their belief by only paying attention to the data that supports their belief and ignoring evidence against.

Astronomy’s divergence as a separate science began in earnest with the invention of the telescope. Until then; ancient civilizations studied the predictable movement of the sun and stars and used this data for celestial navigation and calender making. The science of Astronomy as we know it today could also be called Astrophysics.

Anders Celsius

Both Celsius and Fahrenheit are temperature measurement systems developed by scientists in the 1700′s.  The Celsius system was credited to Anders Celsius, a Swedish astronomer, who invented a virtually identical system 2 years before his death. Celsius’ original measurements where simply reversed; 100 degrees Celsius, in his original system was the freezing point of water and 0 degrees was the boiling point. The term Centigrade was used interchangeably with Celsius: “Centi” meaning 100 and “grade” meaning steps and seemed to be a more apt description for this measurement system, but was officially changed to Celsius in 1948 to avoid confusion, as the term Centigrade is used by the Spanish and French as a unit of angular measurement.

The Fahrenheit scale was developed by Daniel Gabriel Fahrenheit, a German physicist who based his scale on the work of Romer. Fahrenheit altered Romer’s scale by multiplying each standard Romer gradation (boiling and freezing) by 4. This allowed for larger numbers to be used, eliminating the need for fractional measurements.

The Celsius scale is by far the most widely used measure of temperature with a few exceptions; the United States and Belize still commonly use the Fahrenheit scale, although the worldwide scientific community, including in the US and Belize use the Celsius or Kelvin scale.

So; how do you convert Celsius to Fahrenheit and Fahrenheit to Celsius? Fahrenheit = (Celsius x 9/5) + 32 and Celsius = (Fahrenheit – 32) x 5/9

To make it easier to estimate; to convert Celsius to Fahrenheit, double and add 32 and to convert Fahrenheit to Celsius, subtract 32, then divide by 2. Thus; 100 degrees Fahrenheit is approximately 34 degrees Celsius. It is exactly 37.78 degrees Celsius. 15 degrees Celsius is approximately 62 degrees Fahrenheit. It is exactly 59 degrees Fahrenheit.

Cow Pox pustules on a Cow's Udder

Both viruses and bacteria cause diseases in plants and animals. It’s important to note, though, the vast majority of bacteria are harmless to humans, and a great number of bacteria are essential to our survival. Viruses, bacteria, prions and fungus that cause disease are known as pathogens. Pathogens are simply infectious agents; as the word origin suggests in this case: “pathos” means suffering and “gen” means the generation of.  A virus is an interesting entity that hovers on the cusp of being life. It is basic genetic material boiled down to the most essential elements: genes, protein and sometimes, a lipid outer shell, built using the host’s cellular material. That’s it. Bacteria are prokayotic cells, of which there are many, many varieties. Prokaryotes lack a nucleus and have very few (if any) membrane bound organelles (cellular organs wrapped in their own individual coating).

A virus cannot multiply on its own; it needs to be inside a cell in order to divide. Typically, a virus is proliferated in the following manner: first, it attaches to the outer shell of a cell and either through diffusion or chemical messenger channels, is absorbed. Next, the protein covering protecting the viral DNA or RNA (there are both DNA and RNA viruses) dissolves, releasing the virus’ genetic material. The plant, animal, or fungi cell then combines its own DNA with the viral DNA and begins making copies. Since the viral DNA is actually combined with the host’s DNA, any host cell division will also make a copy of the virus. Viruses can also proliferate by cellular lysis: the host cell completely fills up with copies of the virus, causing the cell to burst and spew out viruses which can then infect other cells in the body. The perfect parasite!

Now the biggest, medically relevant difference between viruses and bacteria is how they are treated when infecting a body. Antibiotics only treat bacterial infections; not viral ones; like the Common Cold or Influenza. Your body needs to just batten down the hatches and kill the viral invaders on its own. It has only been very recently that drugs have been developed to treat a virus once it has become symptomatic: Tamiflu and Relenza are but a few. The main defense against viruses is still vaccines: altered forms of the virus introduced to the body to create an immunity “memory”. Our body then recognizes subsequent exposures to the same virus and can mobilize an immune attack accordingly. The etching at the right is Cow Pox, the much less dangerous form of a similar strain called Small Pox. It was discovered that those who were exposed to Cow Pox, did not succumb to Small Pox as the Cow Pox created an immunity memory.

Hospice de la Salpêtrière by Gautier

A psychiatrist is a medical doctor who specializes in mental, illness that can prescribe medications.  Psychiatrists must go to medical school first, then they spend time specializing in their field. Their approach to therapy tends to be more biological and physiological in nature; looking into the physical causes of mental disease.

Psychologists also work with individuals suffering from mental disease, but employ a wider variety of treatment modalities/theories. Psychologists are not medical doctors, therefore, they cannot order tests, perform physical examinations or prescribe medication. Psychologists can be employed in clinical practice – providing individual or group therapy, or in research – working at a university teaching and researching.

In Canada; psychiatrists are medical professionals whose fees are covered by our national medical plan. Psychologists charge an hourly rate and are covered only by extended medical. Because visit to a psychiatrist doesn’t cost a patient out of pocket, wait lists in Canada to see psychiatrists are very long and can take months, and sometimes years before an appointment becomes available.

The lithograph shown here is an artist rendition of 8 different mental disorders – or what were at the time, considered to be mental disorders (all definitions are from Wikipedia):

Dementia: A serious loss of cognitive ability in a previously unimpaired person beyond what might be expected with normal aging.

Megalomania: A psychopathological condition characterized by delusional fantasies of wealth, power, or omnipotence.

Acute Mania: AKA Bipolar Disorder is a category of mood disorders defined by the presence of one or more episodes of abnormally elevated energy levels, cognition, and mood with or without one or more depressive episodes.

Melancholia: a mood disorder of non-specific depression, characterized by low levels of both enthusiasm and eagerness for activity.

Idiocy: a mentally deficient person.

Hallucination: perception in the absence of a stimulus.

Erotic Mania – Wikipedia doesn’t have an article on this disorder which I find quite interesting.

Paralysis – the complete loss of muscle function for one or more muscle groups.

Typical Plant Cell

The biggest difference between plant cells and animal cells is that plant cells have a cell wall surrounding their cell membrane. Animal cells have no such wall. This gives plant cells rigidity and allows them to remain upright. Plant cells have a large vacuole that takes up most of the room inside their membrane. The vacuole controls the movement and storage of nutrients and waste within the cell, and helps maintain the cell’s structure using fluid for support. Plant cells are relatively uniform in structure – they are all roughly the same shape. whereas there are many different kinds, sizes and shapes of animal cells. Plant cells also contain chloroplasts; the organelles that make food needed for the plant’s growth, using sunlight to convert carbon dioxide and water into sugar and oxygen in a process known as photosynthesis (meaning to synthesize using light). The oxygen biproduct of photosynthesis allows Earth to be inhabited by air breathing organisms; simply put, plants make air for us to breathe. Plant cells have plasmodesmata; pores in the cell wall that allow chemical communication between cells.

Typical Animal Cell

Animal cell membranes have all sorts of receptor proteins that become activated to trigger an opening in the membrane to allow hormones, nutrients and waste to move into and out of the cell. Some substances, such as water can diffuse through the cell wall without needing a chemical signal to do so.

Sodium Hydroxide Pellets

An acid is a substance which has a high concentration of H+ ions. Acids have a pH of between 1 and 7. A base is a substance with a high concentration of OH- ions. Bases have a pH of between 8 and 14. The pH scale is defined by Wikipedia as the negative decimal logarithm of hydrogen ion activity in a solution; in laymen’s terms, a substance with less hydrogen ions (H+) and more hydroxide ions (OH-) is said to be basic, or alkaline. A substance with more hydrogen ions and less hydroxide ions is said to acidic. Water, an almost neutral substance, has a pH of approximately 7. When an acid and a base are combined, the main resultant bi-product is water: HOH. Both acids and bases have the potential to be corrosive.

Examples of very corrosive bases include sodium hydroxide (also known as caustic soda or lye) with a pH of 13 (out of a possible 14) and potassium hydroxide (ph 13.5). Highly acidic substances include sulphuric acid; used in car batteries with a pH of 3 and hydroiotic acid (closely monitored acid used for making methamphetamine) with a pH of 1.

Scanning electron microscope image of gold. Individual gold atoms are visible.

In layman’s terms, an atom can only be one atom of one element on the periodic table. You can have an atom of oxygen, or hydrogen. Anymore than one atom; even of the same type (2 oxygens, or 2 hydrogens) is a molecule. One oxygen, one hydrogen and one hydrogen combine to make water, a molecule.

Atoms are basic units of matter, consisting; in most cases, of protons, neutrons and electrons (most hydrogen has no neutrons). Protons are positively charged, meaning they exert a positive force when near other objects of matter. Electrons are negatively charged. Neutrons carry no charge. Think of the ends of batteries. When you insert batteries into a device, the ends must oppose each other. The little nubbin on the top of a battery is the positive end, and the flat end is the negative end. If you are placing two batteries into your, let’s say, xbox 360 remote, one battery will be positive side up and the other will be negative side up. Like charges repel each other whereas opposite charges attract each other. When batteries are placed in this matter, electricity is pulled through the entire device to complete a circuit allowing you to kill that dragon on screen.

Atoms can gain or lose electrons, not protons. Therefore, an atom or molecule that is negatively charged has gained electrons and and one that is positively charged has lost electrons. This is where understanding ions can be a bit confusing: a gain in electrons is denoted by a minus (-) symbol and a loss in electrons is noted by a (+) symbol. The most common examples of ions are H+ and OH- and/or Na+ and Cl-. H+ is hydron. It is an anion of hydrogen (“an” means without, so anions are minus electrons resulting in a positive charge). It is also a measure of acidity on the Ph scale. OH- is hydroxide. It’s a polyatomic cation (“ca” means with, so cations are with extra electrons resulting in a negative charge). OH- is also a measure of alkalinity on the Ph scale. One H+ and one OH- combine to form water; a neutral molecule.

A molecule is two or more atoms combined into a neutral group. Molecules have the same number of protons and electrons so they hold neither a positive or negative charge. Two or more atoms joined together that hold a positive or negative charge are called polyatomic ions (the prefix “poly” means many, but in this specific case, it means two or more).

In summary, I could go into minute details about the nature of atoms and molecules, but to simplify, atoms are single units of one element on the Periodic Table of Elements. Molecules are two or more atoms, of the same or different element bonded together to make a neutral grouping.

Mmmmm. A tasty subject that I can get behind!

Gelato first appeared on the scene in the ancient Roman Empire when snow was brought down from mountain tops, stored underground mixed with flavorings. It didn’t become mainstream, however until just after the Renaissance when refrigeration techniques and special recipes were developed to combine the ingredients for maximum effect. As with many of the best things in life; red wine, sports cars, fine food and coffee, the birthplace of modern ice cream was Italy.

Gelato was the predecessor to ice cream. After the Italians perfected the recipe, Caterina de’ Medici shared the love with France and the rest, to be trite, is history. If Caterina were around, and not covered in worms and dirt, I would kiss her.

So, the main differences between gelato and ice cream then? Gelato has less fat, less sugar, and a more concentrated flavor. It is made in smaller batches that refrigerate and spoil more quickly.

This, keep in mind, is if ice cream is made with real cream; most of the brands in the supermarket are not made with real cream, but rather modified milk ingredients. Food technology being as it is, milk powder, often coming from New Zealand is reconstituted in food factories in the U.S. where a bunch of other non dairy ingredients like seaweed and hydrogenated vegetable oil. In Canada, many ice “cream” manufacturers use a butter-oil sugar blend. Like its name implies, it is made using a combination of fat and sugar; specifically, 51% sugar, classifying it as a confectionery (candy) product, and thus exempt from many of the import tariffs levied on milk products; making it much cheaper to manufacture; and yet, these frozen desserts are increasing in cost. Read your labels.

I digress. Traditionally made ice cream makers use cream and/or egg yolk as the stabilizer to stop it from freezing solid. Gelato makers use a more finely tuned technique of finding the perfect balance between the sugar and water content.

The truly best gelato comes from Italy! Even immigrant Italian families, using traditional Italian recipes, in Italian bowls, and Italian freezers adding bits of ground up Italians, cannot possibly compare. Must be those magic Italian dairy cows!

Alzheimer’s Disease is a neurodegenerative disease characterized in its early stages by the difficulty in acquiring new memories, diminished language capacity, depression, irritability, apathy, aggression, inability to concentrate, long term memory loss, and/or loss of motor control (no, we don’t all have it even when it feels like it sometimes . This combination of symptoms combined with an examination of a patient’s brain post mortem, confirms a diagnosis of Alzheimer’s Disease. Dementia can include all of these symptoms and more, but can have a number of different causes such as stroke, physical injury or substance abuse. Dementia is not a specific diagnosis, but a description of a collection of symptoms that has or has not necessarily been attributed to a specific cause, like injury, etc. The word dementia, although referring to a completely different host of symptoms, is used similarly to the word colic in that they both describe manifestations of a symptoms, but are not a specific diagnosis (colic describes extended periods of crying and irritability in infants between 2 weeks and 3 months old).

In summary, Alzheimer’s Disease is a specific diagnosis, named after a the guy who discovered it – Alois Alzheimer in 1906, whereas dementia describes a collection of symptoms that have a number of possible causes. Alzheimer’s Disease is confirmed by cognitive – behavioural assessments and brain scans, and is confirmed post mortem by an autopsy.