Women longing for a baby advised to opt for ugly men
Handsome men who are lucky in love may not be the best bet as a mate for women hoping to get pregnant, researchers have said.
Published: 7:00AM BST 10 Jul 2009
Uglier men with fewer notches on their belts are likely to be more productive between the sheets, it is claimed.
Research suggests that in many species, the most desirable males restrict their "sperm load" with each mating to ensure enough to go around.
The same could be true of humans and other primates, say scientists.
If they are right, women looking for the best chance of getting pregnant might be advised to avoid handsome lotharios.
The theory proposes that males have evolved to look for the optimum "sperm load" per mating.
This varies depending on how many available females there are to mate with, and what the chances of mating with them are.
Males with the opportunity to mate with a lot of females would be likely to produce less sperm on each occasion than those making fewer sexual conquests.
A smaller "sperm load" reduces the chances of any individual female getting pregnant. However, this is outweighed by the fact that many different females can be impregnated.
Such a trade-off is seen in the wild and has been observed in chickens and fish.
Researchers modelled the concept of "spreading sperm" mathematically in a paper to be published in the journal American Naturalist.
One member of the team, PhD student Sam Tazzyman, from the Centre for Mathematics and Physics in the Life sciences and Experimental biology (CoMPLEX) at University College London, said: "In some species, females mate with many different males. Each male's sperm competes with that of other males in a process known as 'sperm competition'. Since males have finite resources to allocate to breeding, they allocate them carefully to each mating to maximise their number of offspring.
"If a male puts a lot of resources into each mating he will get more offspring per mating, but at the expense of fewer matings. If, on the other hand, a male puts few resources into each mating he will secure less paternity per mating, but will be able to carry out more matings overall. Thus, there is a trade-off between number of matings and success per mating.
"How a male negotiates this trade-off depends on how easy he finds it to attract females. The more attractive a male is, the more females will be willing to mate with him, reducing the value of each mating to him. This means it is optimal for him to contribute fewer sperm per mating. Although this reduces fertility per mating, it maximises the number of offspring he sires overall. Less attractive males secure fewer matings but value each of them more highly, and by allocating more sperm to each mating make the most of their meagre opportunities.
"This leads to the rather paradoxical prediction that matings with attractive males may be less fertile than those with unattractive males."
Whether or not the same principle applied to humans and other primates was still unknown, said the researchers – but there every possibility that it did.
"Human attractiveness is complicated and influenced by a number of factors, including cultural preferences," said Mr Tazzyman.
"Nonetheless, ejaculate size and sperm quality are likely to have been moulded by similar forces, like attractiveness and the number of sexual partners, that are important in other species."
- wong chee tat :)
Friday, July 10, 2009
Absolute darkness to envelop Earth on July 22
Absolute darkness to envelop Earth on July 22
Source: Pravda.Ru
A total solar eclipse is expected to take place on July 22, at about 8:00 a.m. Beijing time. The Moon will cast its shadow on planet Earth for 6 minutes and 39 seconds. It will be the longest eclipse during the latest two millenniums, China’s official Xinhua news agency said.
It will be possible to eyewitness the spectacular phenomenon in India, Nepal, Bhutan, China and Japan. The eclipse will be partially seen in the north-west of Oceania, in Russia’s Far East and in Kazakhstan.
The amazing natural phenomenon will appear in all its beauty for China , scientists of the Chinese Academy of Sciences said.
The last total eclipse of the Sun occurred on August 1, 2008. The next is expected on July 11, 2010. The most remarkable eclipse took place on August 11, 1999, when it coincided with the planet parade and could be observed all across Europe.
Total solar eclipses are rare events. Although they occur somewhere on Earth every 18 months on average, it has been estimated that they recur at any given place only once every 370 years, on average. The total eclipse only lasts for a few minutes at that location, as the Moon's umbra moves eastward at over 1700 km/h. Totality can never last more than 7 min 31 s, and is usually much shorter: during each millennium there are typically fewer than 10 total solar eclipses exceeding 7 minutes.
The next eclipse exceeding seven minutes in duration will not occur until June 25, 2150. The longest total solar eclipse during the 8,000-year period from 3000 BC to 5000 AD will occur on July 16, 2186, when totality will last 7 min 29 s.
- wong chee tat :)
Source: Pravda.Ru
A total solar eclipse is expected to take place on July 22, at about 8:00 a.m. Beijing time. The Moon will cast its shadow on planet Earth for 6 minutes and 39 seconds. It will be the longest eclipse during the latest two millenniums, China’s official Xinhua news agency said.
It will be possible to eyewitness the spectacular phenomenon in India, Nepal, Bhutan, China and Japan. The eclipse will be partially seen in the north-west of Oceania, in Russia’s Far East and in Kazakhstan.
The amazing natural phenomenon will appear in all its beauty for China , scientists of the Chinese Academy of Sciences said.
The last total eclipse of the Sun occurred on August 1, 2008. The next is expected on July 11, 2010. The most remarkable eclipse took place on August 11, 1999, when it coincided with the planet parade and could be observed all across Europe.
Total solar eclipses are rare events. Although they occur somewhere on Earth every 18 months on average, it has been estimated that they recur at any given place only once every 370 years, on average. The total eclipse only lasts for a few minutes at that location, as the Moon's umbra moves eastward at over 1700 km/h. Totality can never last more than 7 min 31 s, and is usually much shorter: during each millennium there are typically fewer than 10 total solar eclipses exceeding 7 minutes.
The next eclipse exceeding seven minutes in duration will not occur until June 25, 2150. The longest total solar eclipse during the 8,000-year period from 3000 BC to 5000 AD will occur on July 16, 2186, when totality will last 7 min 29 s.
- wong chee tat :)
fsck
Decided to test some odd programs and play with my linux box yesterday evening, and I got this (see pic) after booting up. This could be likely that the system may not be properly shutdown. A simple fix using:
fsck -p -v , -p for automatic repair and v for verbose.
If you don't want,
fsck -v , then you have to select yes (y) or no (n) if you want to fix the errors.
Anyway, details about fsck is shown below:
fsck is a Unix utility for checking and repairing file system inconsistencies . File system can become inconsistent due to several reasons and the most common is abnormal shutdown due to hardware failure , power failure or switching off the system without proper shutdown . Due to these reasons the superblock in a file system is not updated and has mismatched information relating to system data blocks, free blocks and inodes .
Modes of operation :
fsck operates in two modes interactive and non interactive :
interactive : the fsck examines the file system and stops at each error it finds in the file system and gives the problem description and ask for user response usually whether to correct the problem or continue without making any change to the file system.
noninteractive :fsck tries to repair all the problems it finds in a file system without stopping for user response useful in case of a large number of inconsistencies in a file system but has the disadvantage of removing some useful files which are detected to be corrupt .
If file system is found to have problem at the booting time non interactive fsck fsck is run and all errors which are considered safe to correct are corrected. But if still file system has problems the system boots in single user mode asking for user to manually run the fsck to correct the problems in file system
Running fsck :
fsck should always be run in a single user mode which ensures proper repair of file system . If it is run in a busy system where the file system is changing constantly fsck may see the changes as inconsistencies and may corrupt the file system .
if the system can not be brought in a single user mode fsck should be run on the partitions ,other than root & usr , after unmounting them . Root & usr partitions can not be unmounted . If the system fails to come up due to root/usr files system corruption the system can booted with CD and root/usr partitions can be repaired using fsck.
command syntax:
fsck [ -F fstype] [-V] [-yY] [-o options] special
-F fstype type of file system to be repaired ( ufs , vxfs etc)
-V verify the command line syntax but do not run the command
-y or -Y Run the command in non interactive mode - repair all errors encountered without waiting for user response.
-o options Three options can be specified with -o flag
b=n where n is the number of next super block if primary super block is corrupted in a file system .
p option used to make safe repair options during the booting process.
f force the file system check regardless of its clean flag.
special - Block or character device name of the file system to be checked/repaired - for example /dev/rdsk/c0t3d0s4 .Character device should be used for consistencies check & repair
phases:
fsck checks the file system in a series of 5 pages and checks a specific functionality of file system in each phase.
** phase 1 - Check Blocks and Sizes
** phase 2 - Check Pathnames
** phase 3 - Check Connectivity
** phase 4 - Check Reference Counts
** phase 5 - Check Cylinder Groups
Error messages & Corrective action :
1.Corrupted superblock - fsck fails to run
If the superblock is corrupted the file system still can be repaired using alternate superblock which are formed while making new file system .
the first alternate superblock number is 32 and others superblock numbers can be found using the following command :
newfs -N /dev/rdsk/c0t0d0s6
for example to run fsck using first alternate superblock following command is used
fsck -F ufs -o b=32 /dev/rdsk/c0t0d0s6
2.Link counter adjustment : fsck finds mismatch between directory inode link counts and actual directory links and prompts for adjustment in case of interactive operation .Link count adjustments are considered to be a safe operation in a file system and should be repaired by giving 'y' response to the adjust ? prompt during fsck.
3.Free Block count salvage : During fsck the number of free blocks listed in a superblock and actual unallocated free blocks count does not match .fsck inform this mismatch and asks to salvage free block count to synchronize the superblock count. This error can be corrected without any potential problem to the file system or files.
4.Unreferenced file reconnection : While checking connectivity fsck finds some inodes which are allocated but not referenced -not attached to any directory . Answering y to reconnect message by fsck links these files to the lost+found directory with their inode number as their name .
To get more info about the files in lost+found 'file' command can be used to see the type of files and subsequently they can be opened in their applications or text editors to find out about their contents. If the file is found to be correct it can be used after copying to some other directory and renaming it.
- http://adminschoice.com/docs/fsck.htm
- wong chee tat :)
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