cells

A eukaryote (/juːˈkæri.oʊt/ or /juːˈkæriət/ yoo-karr-ee-oht or yoo-karr-ee-ət) is any organism whose cells contain a nucleus and other organelles enclosed within membranes. Eukaryotes belong to the taxon Eukarya or Eukaryota. The defining feature that sets eukaryotic cells apart from prokaryotic cells (Bacteria and Archaea) is that they have membrane-bound organelles, especially the nucleus, which contains the […]

A eukaryote (/ju??kæri.o?t/ or /ju??kæri?t/ yoo-karr-ee-oht or yoo-karr-ee-?t) is any organism whose cells contain a nucleus and other organelles enclosed within membranes.

Eukaryotes belong to the taxon Eukarya or Eukaryota. The defining feature that sets eukaryotic cells apart from prokaryotic cells (Bacteria and Archaea) is that they have membrane-bound organelles, especially the nucleus, which contains the genetic material, and is enclosed by the nuclear envelope.[2][3][4] The presence of a nucleus gives eukaryotes their name, which comes from the Greek?? (eu, “well”) and ?????? (karyon, “nut” or “kernel”).[5] Eukaryotic cells also contain other membrane-bound organelles such asmitochondria and the Golgi apparatus. In addition, plants and algae contain chloroplasts. Eukaryotic organisms may be unicellular, ormulticellular. Only eukaryotes have many kinds of tissue made up of different cell types.

Eukaryotes can reproduce both by asexual reproduction through mitosis and sexual reproduction through meiosis. In mitosis, one cell divides to produce two genetically identical cells. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells each with half the number of chromosomes as the original parent cell (haploid cells). These act as sex cells (gametes – each gamete has just one complement of chromosomes, each a unique mix of the corresponding pair of parental chromosomes) resulting from genetic recombination during meiosis.

The domain Eukaryota appears to be monophyletic, and so makes up one of the three domains of life. The two other domains,Bacteria and Archaea, are prokaryotes and have none of the above features. Eukaryotes represent a tiny minority of all living things;[6]even the cells in a human’s body are outnumbered ten to one by bacteria in the gut.[7][8] However, due to their much larger size, eukaryotes’ collective worldwide biomass is estimated at about equal to that of prokaryotes.[6] Eukaryotes first developed approximately 1.6–2.1 billion years ago.

A prokaryote is a single-celled organism that lacks a membrane-bound nucleus (karyon), mitochondria, or any other membrane-bound organelle.[1] The word prokaryote comes from the Greek ??? (pro) “before” and ?????? (karyon) “nut orkernel“.[2][3] Prokaryotes can be divided into two domains, Archaea and Bacteria. Species with nuclei and organelles are placed in the domain Eukaryota.[4]

In the prokaryotes all the intracellular water-soluble components (proteins, DNA and metabolites) are located together in thecytoplasm enclosed by the cell membrane, rather than in separate cellular compartments. Bacteria, however, do possess protein-based bacterial microcompartments, which are thought to act as primitive organelles enclosed in protein shells.[5][6]Some prokaryotes, such as cyanobacteria may form large colonies. Others, such as myxobacteria, have multicellular stages in their life cycles.[7]

Molecular studies have provided insight into the evolution and interrelationships of the three domains of biological species.[8]Eukaryotes are organisms, including humans, whose cells have a well defined membrane-bound nucleus (containing chromosomal DNA) and organelles. The division between prokaryotes and eukaryotes reflects the existence of two very different levels of cellular organization. Distinctive types of prokaryotes include extremophiles and methanogens; these are common in some extreme environments.[1]

connection

The 75-Year Study That Found The Secrets To A Fulfilling Life The Huffington Post  |  By Carolyn Gregoire Posted: 11/08/2013 18:22 IST Updated: 24/08/2013 03:25 IST http://c.brightcove.com/services/viewer/federated_f8/1460906593

The 75-Year Study That Found The Secrets To A Fulfilling Life

Posted: 11/08/2013 18:22 IST Updated: 24/08/2013 03:25 IST

http://c.brightcove.com/services/viewer/federated_f8/1460906593

love is wise

What would you think it’s worth telling future generations about the life you’ve lived and the lessons you’ve learned from it? “I should like to say two things, one intellectual and one moral. The intellectual thing I should want to … Continue reading

What would you think it’s worth telling future generations about the life you’ve lived and the lessons you’ve learned from it?

“I should like to say two things, one intellectual and one moral. The intellectual thing I should want to say is this: When you are studying any matter, or considering any philosophy, ask yourself only what are the facts and what is the truth that the facts bear out. Never let yourself be diverted either by what you wish to believe, or by what you think would have beneficent social effects if it were believed. But look only, and solely, at what are the facts. That is the intellectual thing that I should wish to say.

The moral thing I should wish to say… I should say love is wise, hatred is foolish. In this world which is getting more closely and closely interconnected we have to learn to tolerate each other, we have to learn to put up with the fact that some people say things that we don’t like. We can only live together in that way and if we are to live together and not die together we must learn a kind of charity and a kind of tolerance which is absolutely vital to the continuation of human life on this planet.”

— BBC’s Face to Face interview of Bertrand Russell, British philosopher, logician, mathematician, historian, Nobel Prize


Regrets – Reminders of What Could Have Been

When I look back into my life I see a shadow of what happened and sometimes I wonder of what could have been. With hindsight, it feels like one should have known all along the results of our actions. If … Continue reading

When I look back into my life I see a shadow of what happened and sometimes I wonder of what could have been. With hindsight, it feels like one should have known all along the results of our actions. If I had taken her to my apartment…, if I had taken that memo out of the briefing…, if …. Once we know the right answers to an exam, we can fantasize going back and ace it. The short term consequences of these alternative happenings might be more or less predictable but as time goes on it is impossible to tell if the future of the alternative past is better, worst, or even comparable to our actual present.
Hindsight bias, also known as the knew-it-all-along effect or creeping determinism, is the inclination, after an event has occurred, to see the event as having been predictable, despite little or no objective basis for predicting it, prior to its occurrence. Hindsight bias may cause memory distortion, where the recollection and reconstruction of content can lead to false theoretical outcomes. A person believes he or she “knew it all along”. Such examples are present in the writings of historians describing outcomes of battles, physicians recalling clinical trials, and in judicial systems trying to attribute responsibility and predictability of accidents.
You know (in a way) the way it was but it is impossible to know what could have been.
Regrets distort reality not only in the objectivity of causal dynamics but also in the subjective perception of our emotions. The pleasures and expectations I get from my dreams can never be matched by achieving them.
Real things are more complex and fuzzy than the ideas inside my head, but more important I have only one life, one moment to live and I can only experiment one thing. Once I do, all the I coulds are wasted and gone. There is an old tale that explains this: A man goes on the jungle when he realizes that a Tiger is stalking him. He falls into a panic and runs into a cliff. He rolls down the step and grabs a bush to stop the fall. He sees that another Tiger is waiting for him at the base of the cliff. At that moment a couple of rats start to mince the base of the bush and the man is certain to fall into the Tiger below. Then the man notices some berries just within his reach. He grabs them and his mouth is filled with the refreshing taste of the berries.

Regrets – Reminders of What Could Have Been

When I look back into my life I see a shadow of what happened and sometimes I wonder of what could have been. With hindsight, it feels like one should have known all along the results of our actions. If … Continue reading

When I look back into my life I see a shadow of what happened and sometimes I wonder of what could have been. With hindsight, it feels like one should have known all along the results of our actions. If I had taken her to my apartment…, if I had taken that memo out of the briefing…, if …. Once we know the right answers to an exam, we can fantasize going back and ace it. The short term consequences of these alternative happenings might be more or less predictable but as time goes on it is impossible to tell if the future of the alternative past is better, worst, or even comparable to our actual present.
Hindsight bias, also known as the knew-it-all-along effect or creeping determinism, is the inclination, after an event has occurred, to see the event as having been predictable, despite little or no objective basis for predicting it, prior to its occurrence. Hindsight bias may cause memory distortion, where the recollection and reconstruction of content can lead to false theoretical outcomes. A person believes he or she “knew it all along”. Such examples are present in the writings of historians describing outcomes of battles, physicians recalling clinical trials, and in judicial systems trying to attribute responsibility and predictability of accidents.
You know (in a way) the way it was but it is impossible to know what could have been.
Regrets distort reality not only in the objectivity of causal dynamics but also in the subjective perception of our emotions. The pleasures and expectations I get from my dreams can never be matched by achieving them.
Real things are more complex and fuzzy than the ideas inside my head, but more important I have only one life, one moment to live and I can only experiment one thing. Once I do, all the I coulds are wasted and gone. There is an old tale that explains this: A man goes on the jungle when he realizes that a Tiger is stalking him. He falls into a panic and runs into a cliff. He rolls down the step and grabs a bush to stop the fall. He sees that another Tiger is waiting for him at the base of the cliff. At that moment a couple of rats start to mince the base of the bush and the man is certain to fall into the Tiger below. Then the man notices some berries just within his reach. He grabs them and his mouth is filled with the refreshing taste of the berries.

history of the universe

Uploaded on Apr 11, 2011 Backed by stunning illustrations, David Christian narrates a complete history of the universe, from the Big Bang to the Internet, in a riveting 18 minutes. This is “Big History”: an enlightening, wide-angle look at complexity, life and humanity, set against our slim share of the cosmic timeline.


Uploaded on Apr 11, 2011

Backed by stunning illustrations, David Christian narrates a complete history of the universe, from the Big Bang to the Internet, in a riveting 18 minutes. This is “Big History”: an enlightening, wide-angle look at complexity, life and humanity, set against our slim share of the cosmic timeline.

When I started loving myself

When I started loving myself – A poem by Charlie Chaplin written on his 70th birthday on April 16, 1959: When I started loving myself I understood that I’m always and at any given opportunity in the right place at … Continue reading

When I started loving myself

– A poem by Charlie Chaplin written on his 70th birthday on April 16, 1959:

When I started loving myself
I understood that I’m always and at any given opportunity
in the right place at the right time.
And I understood that all that happens is right –
from then on I could be calm.
Today I know: It’s called TRUST.

When I started to love myself I understood how much it can offend somebody
When I tried to force my desires on this person,
even though I knew the time is not right and the person was not ready for it,
and even though this person was me.
Today I know: It’s called LETTING GO

When I started loving myself
I could recognize that emotional pain and grief
are just warnings for me to not live against my own truth.
Today I know: It’s called AUTHENTICALLY BEING.

When I started loving myself
I stopped longing for another life
and could see that everything around me was a request to grow.
Today I know: It’s called MATURITY.

When I started loving myself
I stopped depriving myself of my free time
and stopped sketching further magnificent projects for the future.
Today I only do what’s fun and joy for me,
what I love and what makes my heart laugh,
in my own way and in my tempo.
Today I know: it’s called HONESTY.

When I started loving myself
I escaped from all what wasn’t healthy for me,
from dishes, people, things, situations
and from everyhting pulling me down and away from myself.
In the beginning I called it the “healthy egoism”,
but today I know: it’s called SELF-LOVE.

When I started loving myself
I stopped wanting to be always right
thus I’ve been less wrong.
Today I’ve recognized: it’s called HUMBLENESS.

When I started loving myself
I refused to live further in the past
and worry about my future.
Now I live only at this moment where EVERYTHING takes place,
like this I live every day and I call it CONSCIOUSNESS.

When I started loving myself
I recognized, that my thinking
can make me miserable and sick.
When I requested for my heart forces,
my mind got an important partner.
Today I call this connection HEART WISDOM.

We do not need to fear further discussions,
conflicts and problems with ourselves and others
since even stars sometimes bang on each other
and create new worlds.
Today I know: THIS IS LIFE!

attribution http://www.citehr.com/299788-when-i-started-loving-myself-poem-charlie.html#ixzz2rZjl7thk

Alan Wilson Watts

One of the most common questions and frustration we have in life is found in the question of what should I do with my life? Alan Wilson Watts (6 January 1915 – 16 November 1973) was a British-born philosopher, writer, … Continue reading

One of the most common questions and frustration we have in life is found in the question of what should I do with my life?

Alan Wilson Watts (6 January 1915 – 16 November 1973) was a British-born philosopher, writer, and speaker, best known as an interpreter and populariser of Eastern philosophy for a Western audience. Born in Chislehurst, he moved to the United States in 1938 and began Zen training in New York. Pursuing a career, he attended Seabury-Western Theological Seminary, where he received a master’s degree in theology. Watts became an Episcopal priest then left the ministry in 1950 and moved to California, where he joined the faculty of the American Academy of Asian Studies.

Watts gained a large following in the San Francisco Bay Area while working as a volunteer programmer at KPFA, a Pacifica Radio station in Berkeley. Watts wrote more than 25 books and articles on subjects important to Eastern and Western religion, introducing the then-burgeoning youth culture to The Way of Zen (1957), one of the first bestselling books on Buddhism. In Psychotherapy East and West (1961), Watts proposed that Buddhism could be thought of as a form of psychotherapy and not a religion. He also explored human consciousness, in the essay “The New Alchemy” (1958), and in the book The Joyous Cosmology (1962).

Towards the end of his life, he divided his time between a houseboat in Sausalito and a cabin on Mount Tamalpais. His legacy has been kept alive by his son, Mark Watts, and many of his recorded talks and lectures are available on the Internet. According to the critic Erik Davis, his “writings and recorded talks still shimmer with a profound and galvanizing lucidity.”[3]

New Microbe Found in Two Distant Clean Rooms

November 06, 2013 A rare, recently discovered microbe that survives on very little to eat has been found in two places on Earth: spacecraft clean rooms in Florida and South America. Microbiologists often do thorough surveys of bacteria and other microbes in spacecraft clean rooms. Fewer microbes live there than in almost any other environment […]

November 06, 2013

A rare, recently discovered microbe that survives on very little to eat has been found in two places on Earth: spacecraft clean rooms in Florida and South America.

Microbiologists often do thorough surveys of bacteria and other microbes in spacecraft clean rooms. Fewer microbes live there than in almost any other environment on Earth, but the surveys are important for knowing what might hitch a ride into space. If extraterrestrial life is ever found, it would be readily checked against the census of a few hundred types of microbes detected in spacecraft clean rooms.

The work to keep clean rooms extremely clean knocks total microbe numbers way down. It also can select for microbes that withstand stresses such as drying, chemical cleaning, ultraviolet treatments and lack of nutrients. Perversely, microbes that withstand these stressors often also show elevated resistance to spacecraft sterilization methodologies such as heating and peroxide treatment.

“We want to have a better understanding of these bugs, because the capabilities that adapt them for surviving in clean rooms might also let them survive on a spacecraft,” said microbiologist Parag Vaishampayan of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead author of the 2013 paper about the microbe. “This particular bug survives with almost no nutrients.”

This population of berry-shaped bacteria is so different from any other known bacteria, it has been classified as not only a new species, but also a new genus, the next level of classifying the diversity of life. Its discoverers named it Tersicoccus phoenicis. Tersi is from Latin for clean, like the room. Coccus, from Greek for berry, describes the bacterium’s shape. The phoenicis part is for NASA’s Phoenix Mars Lander, the spacecraft being prepared for launch in 2007 when the bacterium was first collected by test-swabbing the floor in the Florida clean room.

Some other microbes have been discovered in a spacecraft clean room and found nowhere else, but none previously had been found in two different clean rooms and nowhere else. Home grounds of the new one are about 2,500 miles (4,000 kilometers) apart, in a NASA facility at Kennedy Space Center and a European Space Agency facility in Kourou, French Guiana.

A bacterial DNA database shared by microbiologists worldwide led Vaishampayan to find the match. The South American detection had been listed on the database by a former JPL colleague, Christine Moissl-Eichinger, now with the University of Regensburg in Germany. She is first co-author of the paper published this year in the International Journal of Systematic and Evolutionary Microbiology identifying the new genus.

The same global database showed no other location where this strain of bacteria has been detected. That did not surprise Vaishampayan. He said, “We find a lot of bugs in clean rooms because we are looking so hard to find them there. The same bug might be in the soil outside the clean room but we wouldn’t necessarily identify it there because it would be hidden by the overwhelming numbers of other bugs.”

A teaspoon of typical soil would have thousands more types of microbes and billions more total microbes than an entire cleanroom. More than 99 percent of bacterial strains, as identified from DNA sequences, have never been cultivated in laboratories, a necessary step for the various types of characterization required to identify a strain as a new species.

Microbes that are tolerant of harsh conditions become more evident in clean room environments that remove the rest of the crowd.

“Tersicoccus phoenicis might be found in some natural environment with extremely low nutrient levels, such as a cave or desert,” Vaishampayan speculated. This is the case for another species of bacterium (Paenibacillus phoenicis) identified by JPL researchers and currently found in only two places on Earth: a spacecraft clean room in Florida and a bore hole more than 1.3 miles (2.1 kilometers) deep at a Colorado molybdenum mine.

Ongoing research with Tersicoccus phoenicis is aimed at understanding possible ways to control it in spacecraft clean rooms and fully sequencing its DNA. Students from California State University, Los Angeles, have participated in the research to characterize the newly discovered species.

The California Institute of Technology, Pasadena, operates JPL for NASA.

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov