Pollen from a variety of common plants as seen through an electron microscope: sunflower (Helianthus annuus), morning glory Ipomoea purpurea, hollyhock (Sildalcea malviflora), lily (Lilium auratum), primrose (Oenothera fruticosa) and castor bean (Ricinus communis). The image is magnified some x500, so the bean shaped grain in the bottom left corner is about 50 ¼m long. The photo was taken at the Dartmouth Electron Microscope Facility, Dartmouth College. (Date of Image: Unknown).

Pollen from a variety of common plants as seen through an electron microscope: sunflower (Helianthus annuus), morning glory Ipomoea purpurea, hollyhock (Sildalcea malviflora), lily (Lilium auratum), primrose (Oenothera fruticosa) and castor bean (Ricinus communis). The image is magnified some x500, so the bean shaped grain in the bottom left corner is about 50 ¼m long. The photo was taken at the Dartmouth Electron Microscope Facility, Dartmouth College. (Date of Image: Unknown).

Soap Bubbles for Predicting Cyclone Intensity?

image

Could soap bubbles be used to predict the strength of hurricanes and typhoons? However unexpected it may sound, this question prompted physicists at the Laboratoire Ondes et Matière d’Aquitaine (CNRS/université de Bordeaux) to perform a highly novel experiment: they used soap bubbles to model atmospheric flow. A detailed study of the rotation rates of the bubble vortices enabled the scientists to obtain a relationship that accurately describes the evolution of their intensity, and propose a simple model to predict that of tropical cyclones.

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Evidently bats understand just how important foreplay is when it comes to worthwhile sex.
Male flying foxes have been observed grooming their genital organ prior to mating attempts, leading to arousal. They will then approach a female who will give something of a chase, backing away for approximately a minute. The female will then stop and allow the male to perform cunnilingus before mounting her. After copulation is through, the actions of the male depend on which species of bat you’re observing. Some will resume cunnilingus, while others will groom their own genitals once more. The current theory is that oral sex is important for competition, as it can clean the genitals of a previous mate’s sperm, and it also leads to longer sex.
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Evidently bats understand just how important foreplay is when it comes to worthwhile sex.

Male flying foxes have been observed grooming their genital organ prior to mating attempts, leading to arousal. They will then approach a female who will give something of a chase, backing away for approximately a minute. The female will then stop and allow the male to perform cunnilingus before mounting her. After copulation is through, the actions of the male depend on which species of bat you’re observing. Some will resume cunnilingus, while others will groom their own genitals once more. The current theory is that oral sex is important for competition, as it can clean the genitals of a previous mate’s sperm, and it also leads to longer sex.

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sinobug

sinobug:

FAMILY PLANNING

This montage documents the growth of the same Paper Wasp nest (Polistes sp., Vespidae) from the time when the cells were small and contained eggs only, progressively expanding to house several generations of wasps-to-be from eggs to chubby larva to capped pupal cells. And always there is a vigilant and defiant adult to guard the brood.

Click the images to see larger size and the dates the images were taken. (Top two images, April 7th, 2012; centre image, June 5th, 2012; fourth image, June 17th, 2012; final image, July 4th, 2012)

by Sinobug (itchydogimages) on Flickr.
Pu’er, Yunnan, China

See more Chinese Hymenopterans (wasps, hornets, bees, ants and sawflies) on my Flickr site HERE…..

nursingisinmyblood

bklynmed:

What is apoptosis?


There are two ways that a cell can die: necrosis and apoptosis. Necrosis occurs when a cell is damaged by an external force, such as poison, a bodily injury, an infection or getting cut off from the bloodsupply (which might occur during a heart attack or stroke). When cells die from necrosis, it’s a rather messy affair. The death causes inflammation that can cause further distress or injury within the body.

Apoptosis, on the other hand, is relatively civil, even though it may not sound so at first — it’s when a cell commits suicide. How is that better than necrosis? For one thing, the cleanup is much easier. It’s sometimes referred to as programmed cell death, and indeed, the process of apoptosis follows a controlled, predictable routine.

When a cell is compelled to commit suicide (we’ll get to the triggers for apoptosis in just a minute), proteins called caspases go into action. They break down the cellular components needed for survival, and they spur production of enzymes known as DNases, which destroy the DNA in the nucleus of the cell. It’s like roadies breaking down the stage in an arena after a major band has been through town. The cell shrinks and sends out distress signals, which are answered by vacuum cleaners known as macrophages. The macrophages clean away the shrunken cells, leaving no trace, so these cells have no chance to cause the damage that necrotic cells do.

Apoptosis also differs from necrosis in that it’s essential to human development. For example, in the womb, our fingers and toes are connected to one another by a sort of webbing. Apoptosis is what causes that webbing to disappear, leaving us with 10 separate digits. As our brains develop, the body creates millions more cells than it needs; the ones that don’t form synaptic connections undergo apoptosis so that the remaining cells function well. Programmed cell death is also necessary to start the process of menstruation.

That’s not to say that apoptosis is a perfect process. Sometimes, the wrong cells kill themselves off, and sometimes, the ones that should say “auf Wiedersehen” stick around instead. This brings us to our discussion of the triggers of apoptosis. Rather than dying due to injury, cells that go through apoptosis die in response to signals within the body. When cells recognize viruses and gene mutations, they may induce death to prevent the damage from spreading. When cells are under stress, as may happen when free radicals are on the loose or when a person undergoes radiation, apoptosis can occur. But there are also signals within the body that send the message that a cell should continue living. All cells have varying level of sensitivity to the positive and negative triggers, so sometimes the wrong cells live and die.

Scientists are trying to learn how they can modulate apoptosis, so that they can control which cells live and which undergo programmed cell death. Anti-cancer drugs and radiation, for example, work by triggering apoptosis in diseased cells. Many diseases and disorders are linked with the life and death of cells — increased apoptosis is a characteristic of AIDS, Alzheimer’s and Parkinson’s disease, while decreased apoptosis can signal lupus or cancer. Understanding how to regulate apoptosis could be the first step to treating these conditions.

source 

photo one by Sarit Larisch and Hermann Steller , Rockefeller University

latter photo sources