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Das unter Informatik-Studenten und professionellen Programmierern sehr
beliebte Buch "Java ist auch eine Insel" steht ab sofort in der siebten
Auflage zur Verfügung. Neben der gedruckten Variante für knapp 50 Euro
steht es auch online zum Lesen bereit.
Es richtet sich sowohl an Einsteiger und Profis. Es behandelt
die zahlreichen Gebiete der Java-Programmierung sehr kompakt aber
trotzdem verständlich. Neben den Grundlagen der Programmiersprache
werden auch die mehr ins Detail gehenden Themen behandelt,
beispielsweise Sicherheitskonzepte, Datenbankmanagement sowie
JavaServer Pages und Servlets.
Die neue siebte Auflage enthält erstmals Informationen zur kommenden
Java-Ausgabe 7. Zudem wurden die Kapitel über die Themen
Objektorientierung, Swing und JSP überareitet. Außerdem geht der Autor
Christian Ullenbooms auf die Änderungen in den Entwicklungsumgebungen
Eclipse 3.3 und NetBeans 6 ein. Das Buch umfasst inzwischen 1492 Seiten
und ist dadurch 12,5 Megabyte groß. Alternativ steht auch eine
HTML-Version online zur Verfügung.
HTML-Ausgabe: Java ist auch eine Insel - 7. Auflage
Download: Java ist auch eine Insel - 7. Auflage (12,5 MB)Powered by ScribeFire.
Over
70 % of the adult body is made of water. Our body cannot function
without water: a human will die faster of thirst than of hunger. A 68
kg person has about 40 liters of water in the body. 23-26% is found
inside the cells, 7,5 % in the space between the cells and up to 4
liters in the blood. This volume must be kept constant. Food does not
deliver enough moisture; doctors say we should drink two liters of
water daily, since our body eliminates water through urine, sweat (we
sweat even when temperature is under 0), feces and breath.
Water is never enough: you will compensate for the body's ability to
eliminate water (a state called hyperhydration) only by drinking over
7.5 liters of water in 24 hours. Here are 14 reasons why you should
drink a sufficient amount of water daily:
1. Dehydration (lower water amount) affects body functioning
- Digestion, excretion and the constant maintenance of the body
temperature cannot be ensured if water is under the normal levels in
the body. The water balance is connected to the electrolyte levels
(mineral salts blood ratio). The sodium level in the blood is the
source which can ‘tell’ us the hydration level in our body.
When there is too much sodium in the blood, the body retains water to
dilute the sodium excess and less urine is produced.
2. Thirst - this is a sensation forming in the brain nuclei, which can
be easily ‘cheated’. That's why dehydration may not cause
immediate thirst. You may be dehydrated without being thirsty. When
you're thirsty, you're already dehydrated. Dehydration and thirst are
more connected when you practice sports.
3. Diet - Dieting means eating less, and since foods can be an
important source of water for our body, you must replace the water
ingested through food by drinking that equal amount.
4. Temperature - Heat boosts the required amount of water, as you sweat
more to cool down the body. Water consume must increase during summer.
The same happens during exercising: muscular contraction releases heat,
the body temperature increases, and so does sweating. An adult needs
one extra liter of water for each hour of exercising.
5. Kidney - Chronic dehydration has been connected to the development
of kidney calculi. This works also for chronic urinary infections. Also
the kidneys work better with abundant water.
6. Skin - Aging skin loses water. Hydrated skin is smoother and
healthier. Water feeds the skin and cleans the body of toxins,
that’s why hydrated skin looks healthy and shiny.
7. Toxins - Water is involved in all the metabolic reactions. Diets
rich in proteins require higher amounts of water, because higher
amounts of toxic nitrogen compounds form and they are easier to be
eliminated by the organism in the presence of abundant water (because
kidney and sweat glands work faster).
8. Diuresis - Water ingestion speeds up the elimination of liquids and drugs from the organism.
9. Aging - In case of elder people, the sensation of thirst decreases,
especially if they are sedentary or suffer from dementia. Their kidneys
lose more water and they should drink a cup of water every two hours.
10. Slimming – Water has no calories. Drink water before eating,
and it will decrease the sensation of an ‘empty stomach’,
the hunger sensation. Do not drink water after eating! This will dilute
the ingested food, which will pass faster through the stomach and
hunger sensation will return earlier. Also, water dilutes the digestive
juices in the stomach.
11. Vomits. People may not realize that through vomiting they lose huge
amounts of water and electrolytes. Diarrhea and fever (through sweat)
too have the same effect and the body loses sodium and potassium, which
are very important in the water balance. Up to 4 liters daily can be
lost through severe vomiting or diarrhea, that's why salts must have a
replacement. Isotonic drinks or alkaline solutions are recommended,
too.
12. Diabetes – the only symptoms of the diabetes insipidus are
the exaggerated thirst and the excessive amount of urine. It can start
gradually or suddenly at any age and it is the result of a deficiency
of antidiuretic hormones, which limit the production of excessive
urine. A person can drink enormous amounts (4 to 30 liters) of liquid
to compensate the loss produced by so much urine.
13. Coffee and tea – caffeine is a mild diuretic, speeding up the
urination cycle, but at the same time, it "steals" the calcium and
electrolytes (that are eliminated through urine). Coffee also increases
water loss through feces, since it functions as a laxative.
14. Alcohol – you say that you're going to get hydrated with a
beer. That's false: you're going to lose more water. It's not only
about the diuretic effect of the beer. After a drinking bout, on
average 3 glasses of water are required to rehydrate your body. Because
by drinking you lose many fluids, going to bed dehydrated will make the
body unable to eliminate the alcohol, and (in concentrated levels) the
alcohol will induce nasty effects in time.Powered by ScribeFire.
Some
are trying hard to show the beneficial effects that coffee has on our
health, others see it as the devil’s beverage. Others say it’s rather a
bogus. Read on and decide for yourself who’s right!
1. Some say that the energy boosting effect of the morning coffee is
only in your mind and you should sleep more. The caffeine eases
withdrawal symptoms accumulating overnight, but does not make people
more alert. Only people who do not regularly drink coffee will get a
‘push-up’ from caffeine, while the British Coffee Association insists
that regular drinkers do feel more alert.
Regular coffee drinkers swear that their morning caffeine wakes them
up, and in case they don’t take it, they feel they have no energy and
will surely be less efficient in their activities. Researches show that
a first caffeine intake does not make the individuals more alert than
those who do not drink coffee are.
Others insist that moderate coffee consumption of four to five cups per
day is perfectly safe for the general population and has a beneficial
effect on alertness and performance even in the case of regular coffee
drinkers.
Caffeine, the main active chemical of coffee, blocks adenosine, a
chemical that makes you naturally drowsy, increasing concentration and
reaction speed. But the long term effects can be really tricky. Once
the temporary stimulation stops, the brain cells start needing caffeine
for stimulation and a sudden neural sluggishness installs.
2. Caffeine has been found to prevent cognitive decline in the elderly
women. Women aged 65 and older who consumed over three cups of coffee
(or the same caffeine levels in tea) daily scored better over time on
memory tests than women who drank one cup or less of coffee/tea daily
did. The memory benefits of the caffeine rise with age – coffee
drinkers being 30 % less exposed to memory impairment at age 65 and 70
% less over 80. Still, caffeine consumers did not have lower rates of
dementia.
Caffeine seems to slow the dementia process rather than prevent it. Why
caffeine has a slightly different effect on women than it does in men
is a puzzle.
Caffeine has been found also to protect against Parkinson’s disease and
depression, and this could be linked to its inhibiting effect on
adenosine receptors. Depression is eased because caffeine increases
dopamine, the "happy feeling" hormone, in your brain.
3. Italian researchers found that coffee defends against blepharospasm,
an involuntary eye spasm which makes patients blink uncontrollably,
which may turn into a severe vision impairment, and in severe cases,
this can make the patients functionally blind (despite intact eyeballs)
as they cannot impede closing their eyes. One to two cups daily have
this effect. The blepharospasm onset age was delayed by coffee
drinking, with 1.7 years for each extra daily cup, and this could be
due to caffeine's effect on the adenosine receptors.
4. Everybody knows the laxative effect of coffee. Brewed coffee also
contains soluble cellulose fibers, which help the body absorb vital
nutrients, keep a lid on cholesterol and fight constipation. The
amounts are of 0.47-0.75 grams of fiber per 100 ml. Freeze-dried coffee
came out on top. Men comsume on average about 38 g of fiber a day and
women around 25 g. A 240 ml cup of coffee could contain as much as 1.5
g of fiber (3.2 cups means 5 g of fiber).
5. High coffee consumption (more than three cups per day for years)
increases loss of bone mineral density. Caffeine is a mild diuretic,
speeding up the urination cycle, but "steals" calcium which is lost
through urine. Long term, heavy caffeine use leads to a rapid
development of osteoporosis.
6. The effect of coffee on the cardiovascular health is controversial:
some say it’s good, others that it is a risk factor. Caffeine blocking
adenosine constricts the brain's blood vessels. The heart beats rate
increases, muscles tighten, the blood pressure booms, blood vessels
near the surface constrict and more blood flows to the muscles.
Researches show that blood pressure and heart rate spurred in healthy
sedentary adults drinking two cans of caffeine containing drinks daily
by up to 11 %.
But if you're going to practice sports, the heart beats can increase up
to a dangerously high level, while triggering extremities shivering and
nausea. On the long term, the unnatural heart racing is unhealthy, and
can trigger heart conditions.
7. Caffeine causes sleep disturbances. Don't even think about drinking
coffee or other caffeine containing beverages before sleep. And
remember that the alkaloid needs 12 hours to be completely eliminated
from your body.
8. A new research has found that coffee could cut the risk of skin
cancer. 6 cups of caffeinated coffee daily lowered the likelihood of
developing skin cancer by 35 %, while 2-3 cups lowered it by 12 %.
Caffeine is believed to impede cells dividing in the tumor, or to work
as an antioxidant. One research found coffee and exercising fight
against sun-induced skin cancer by 400 %.
Other researches suggest that coffee could be beneficial also against breast cancer.
9. Coffee fights gout symptoms! The beverage lowers uric acid levels on
short term, easing the most common and excruciatingly painful
inflammatory arthritis in adult males. Drinking 4-5 cups of coffee
daily significantly decreases the risk of gout by 40 % and over 6 cups
per day by 59 %. Tea (which contains caffeine) has no impact on gout
incidence, thus other chemical than caffeine induces this effect; the
main suspected being the phenol chlorogenic acid, a powerful
antioxidant.
10. Two cups of coffee reduce significantly post-gym muscle pain.
Caffeine consumed one-hour before going to the gym induces a 48 %
decrease in pain; those who drink caffeine before the near-maximum
force test have 26 % drop in soreness. Caffeine boosts endurance, and
one study discovered caffeine to decrease pain during
moderate-intensity cycling. By blocking the receptors for adenosine,
released in response to inflammation and implied in pain sensation,
coffee could have this effect. Caffeine seems to be more efficient than
conventional pain and soreness reliever drugs, like naproxen (the
active ingredient in Aleve), aspirin and ibuprofen.
11. Caffeine mixed with acetaminophen (paracetamol),
one of the most common painkillers used in the US and Europe could harm
your liver. The caffeine was discovered to triple the quantity of a
toxic byproduct, N-acetyl-p-benzoquinone imine (NAPQI), produced by the
enzyme that breaks down the acetaminophen. Still, the effects would be
determined by the daily consume of 20-30 cups of coffee.
12. Caffeine gets women in the mood for sex, especially in moderate
amounts and when the women are not heavy drinkers. The chemical is also
known to increase excitability in men.
Interestingly, female rats that received the middle dose of caffeine
had quicker return visits to the males than the highest dose tested.
13. Researches show that the consume of unfiltered coffee increases the
level of cholesterol. Why? Because coffee contains a substance called
cafestol which triggers the rise of cholesterol levels. The cafestol
blocks a receptor in an intestinal pathway crucial for cholesterol
regulation, and is the most potent food chemical to do this.
By pouring hot water over the ground coffee, the cafestol is extracted.
The same thing happens when the ground coffee is boiled in water by
several times, like in the case of Turkish coffee or Scandinavian brew,
or a paper filter is employed, like in French coffee. If the coffee is
made without the filter, the cafestol remains in the prepared beverage.
A cup of unfiltered coffee contains up to 4 milligrams of cafestol that
can raise the cholesterol level by 1 %. The espresso coffee contains
cafestol, as it is not prepared with a filter. Still, this type of
coffee can increase less the cholesterol if you use a small cup. Less
espresso means less cafestol, probably just 1-2 mg per cup. Still, 5
cups of espresso can raise the cholesterol by 2 %.
Decaffeinated coffee contains cafestol, since removing caffeine does not influence the other compound.
14. Coffee can kill you! Just as any other drug, in small amounts,
caffeine (and coffee) is a stimulant. But the coffee plant synthesizes
the alkaloid with the purpose of killing…its natural consumers. The
grazer eating too much coffee will die. We, too, may be killed. The
uncontrolled heart beats are the prelude of a heart attack.
Over 400 mg of caffeine (found in 4-5 cups of brewed coffee) can cause
caffeine intoxication. Some even snort caffeine powder, which results
in a more rapid and intense reaction. The symptoms are just like those
induced by any other drug: restlessness, nervousness, excitement,
insomnia, face flushing, increased urination, gastrointestinal
disturbance, muscle twitching, a rambling flow of thought and speech,
irritability, irregular heart beat, and psychomotor agitation.
Deadly coffee doses have not been tested on people, but in rats the
average lethal dose (LD50) of caffeine is 192 mg/kg: 50 % of the rats
died after consuming this quantity. In humans, however, the value would
be linked to weight and each one's sensitivity, to about 150 to 200
mg/kg of body mass.
So, you have to drink 80 to 100 cups of coffee very quickly to die...
This also varies with the coffee variety, and cup size, as this
determines how much caffeine enters your body. Actually, cases of death
caused by coffee drinking have not been reported yet (at least from
rapid drinking; the chronic effects are another story) but caffeine
pills (just 2 g) are much more effective and have been proven lethal. Powered by ScribeFire.
