Genes from algae allow blind mice to see

 

 

 

BLIND people could one day have their sight restored thanks to a treatment that borrows a gene from an unlikely source - algae - and inserts it into the retina. The technique has succeeded in restoring the ability to sense light and dark to blind mice, and clinical trials in humans could begin in as little as two years.

"The idea is to develop a treatment for blindness," says Alan Horsager, a neuroscientist at the Institute of Genetic Medicine at the University of Southern California, Los Angeles, who leads the research. "We introduce a gene that encodes a light-sensitive protein, and we target the expression of that gene to a subset of retinal cells."

Some 15 million people worldwide have some form of blindness, such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). In people with these conditions the photoreceptors, which transform light hitting the eye into electrical impulses, are damaged, preventing the brain from receiving image information.

As the global population ages, it is thought that the number of people affected will increase. There are experimental attempts to develop electronic implants and to use stem cells to grow new retinal tissues to restore sight, but there is currently no commercial treatment available.

Horsager hopes his work will change that. His team's approach is based on gene therapy, where a "tame" virus is harnessed to transfer a gene into target cells in the recipient. In this case the gene of interest is one that makes Channelrhodopsin-2 (ChR2), a photosensitive protein used by unicellular algae to help them move towards light. The target cells are bipolar cells in the retina.

The retina contains three cellular layers that work together to detect and transmit light signals to the brain (see diagram). The first layer contains the photoreceptors - the rods and cones that detect light. The second layer is made of bipolar cells that act as a conduit between the photoreceptor and the third type of cell, the ganglion, which transmits the light signals to the brain.

In people with RP and AMD, the photoreceptors have been damaged and lost, so the ganglion cells do not receive signals and the brain cannot produce an image. The idea behind the gene therapy is to make the bipolar cells function as photoreceptors by producing ChR2. The modified bipolar cell would then be able to sense light and transmit a signal to the ganglion.

Horsager's team tested their technique using three groups of mice: one with normal vision, and two groups of mouse strains that naturally become blind with age in a similar way to people with RP and AMD. One blind group was treated with the gene therapy, while the other two groups were not.

Treated mice received a sub-retinal injection of the virus containing the algal gene. Ten weeks after the injection, the team dissected some of the mice and used immunolabelling to see whether ChR2 was being expressed in the retina. They found that the protein was being made by the bipolar cells.

But the strongest evidence of the treatment's success came when treated mice were put in the centre of a water maze with six possible corridors, only one of which led to a ledge that the mice could clamber out of the water onto. With a guiding light shining at the end of the corridor which contained the ledge, the gene-therapy mice were able to find the escape platform 2.5 times faster, on average, than the untreated blind mice. The work will appear in Molecular Therapy.

Repeating the test 10 months later, the team found that the treated mice were still showing significant improvements in vision compared with the untreated blind mice. "Our expectation is that this would be a one-time treatment that is permanent or semi-permanent," says Horsager.

Concerns have been raised about the safety of gene therapy in the past, not least about links between the viruses used to transfer the genes and disease. Horsager says the algal genes were only expressed in the target cells, and that there is no evidence of an immune response in the mice, suggesting that the transfer of the foreign gene has been restricted to the bipolar cells.

However, small amounts of ChR2 DNA were found in other tissues. "Regulatory agencies would be very concerned that ChR2 DNA was found in tissues outside of the treated eye," says Robert Lanza, of Advanced Cell Technology in Worcester, Massachusetts. Horsager's team believe the rogue DNA is due to cross-contamination during the analysis process.

"It's a good paper, and it's clear that they are heading towards a clinical trial with the information they are gathering," says Pete Coffey of the department of ophthalmology at University College London. But he points out that although there is a statistical difference between the performance of the treated and untreated mice, that difference is small.

http://www.newscientist.com/article/mg21028083.100-genes-from-algae-allow-blind-mice-to-see.html

 

Covert hard drive fragmentation embeds a spy's secrets

GOOD news for spies. There is now a way to hide data on a hard drive without using encryption. Instead of using a cipher to scramble text, the method involves manipulating the location of data fragments.

The inventors say their method makes it possible to encode a 20-megabyte message on a 160-gigabyte portable hard drive. It hides data so well that its existence would be "unreasonably complex" to detect, they say.

Encryption should sometimes be avoided, says Hassan Khan at the University of Southern California in Los Angeles, because the gobbledegook it creates is a dead giveaway: it shows someone might have something to hide. That could spell disaster for someone trying to smuggle information out of a repressive country.

So "steganography", hiding data in plain sight, is coming to the fore. Normally, data intended to be secret is added to the pixels in digital images, or used to change the transmission timing of internet packets. But these techniques are well known and easily detected, says Khan. So, with colleagues at the National University of Science and Technology in Islamabad, Pakistan, he has developed an alternative.

Their technique exploits the way hard drives store file data in numerous small chunks, called clusters. The operating system stores these clusters all over the disc, wherever there is free space between fragments of other files.

Khan and his colleagues have written software that ensures clusters of a file, rather than being positioned at the whim of the disc drive controller chip, as is usually the case, are positioned according to a code. All the person at the other end needs to know is which file's cluster positions have been encoded.

The code depends on whether sequential clusters in a file are situated adjacent to each other on the hard disc or not. If they are adjacent, this corresponds to a binary 1 in the secret message. If sequential clusters are stored in different places on the disc, this encodes a binary 0 (Computers and Security, DOI: 10.1016/j.cose.2010.10.005). The recipient then uses the same software to tell them the file's cluster positions, and hence the message. The researchers intend to make their software open source.

"An investigator can't tell the cluster fragmentation pattern is intentional- it looks like what you'd get after addition and deletion of files over time," says Khan. Tests show the technique works, as long as none of the files on the hard disc are modified before handover.

"The real strength of this technique is that even a completely full drive can still have secret data added to it – simply by rearranging the clusters," adds Khan.

Others are impressed with the technique but see limitations.

"This type of steganography could be used by spies, police or informants - but the risk is that it requires direct contact to physically exchange the USB device containing the secret data," says Wojciech Mazurcyk, a steganographer at Warsaw University of Technology in Poland. "So it lacks the flexibility of internet steganography. Once you embed the secret data on the disk it is not easy to modify it."

But won't making the covert hard disk software open source – as the group plans - encourage its use by criminals and terror groups?

"It's how security vulnerability disclosure works," says Khan. "We have identified that this is possible. Now security agencies can devise techniques to detect it." He adds that his team have had no issues with either US or Pakistani security agencies over their development of this secret medium - despite current political tensions between the two nations.

"The use of steganographic techniques like this is likely to increase," says Fred Piper, director of information security at Royal Holloway, University of London. "Eavesdroppers can learn much from the fact that somebody is encrypting a message."

http://www.newscientist.com/article/mg21028095.200-covert-hard-drive-fragmentation-embeds-a-spys-secrets.html

Forensic Anthropology

Forensic Anthropology

What is Forensic Anthropology?

 

"Forensic anthropology is the scientific discipline that applies the methods of physical anthropology and archeology to the collection and analysis of legal evidence.  Description and identification of skeletonized human remains are standard work for forensic anthropologists, but the expertise of the forensic anthropologist is also applicable to a wide variety of other problems.  The common denominator is hard tissues:  bones, teeth, and sometimes cartilage"  (Burns 1999:3).

Therefore, in order to practice forensic anthropologist, one must first and foremost study physical anthropology, with an emphasis on skeletal biology, and secondarily, train in archaeology in order to assist in the search for and excavation of skeletal material.  A physical anthropologist may also be asked to examine a body that is badly or completely decomposed or burned. It is the job of the anthropologist to identify whether or not the bones are human, and if they are human, to develop a biological profile, which will aid in the identification of the person(s). A biological profile consists of the person's ancestry, sex, age at the time of death, and stature, as well as any trauma sustained to the skeleton that may aid in the identification of the individual, or give indications of cause or manner of death.

Trauma

Antemortem Trauma
Perimortem Trauma
Postmortem Trauma

What is the difference between Cause of Death and Manner of Death?  

Cause of death is the way in which someone died (or what caused his or her death). A few common examples are gunshot wound, stabbing, asphyxiation (strangulation), and being bludgeoned to death (usually referred to as blunt force trauma) Manner of death is classified as one of five types:  homicide, suicide, accidental, natural or unknown. 

Reference:
Burns, Karen Ramey
1999   Forensic Anthropology Training Manual.  Prentice-Hall, N.J.

How to become a Forensic Anthropologist?

If you want to become a forensic anthropologist, you have to go to university and study physical anthropology. Physical anthropology is one of four sub-disciplines of anthropology. Cultural anthropology, archaeology, and linguistics are the others. Physical anthropology encompasses  topics such as primatology, evolution, and skeletal biology, to name a few. So you have to go to university to get a degree in physical anthropology, and you should try and focus your studies on human osteology. From there, you must continue your education, because in order to practice as a forensic anthropologist, you need a minimum of a master's in physical anthropology with a lot of experience, or a PhD in physical anthropology. However it is possible to study specific aspects of physical anthropology at the master's level, such as skeletal biology. It is also possible to study forensic anthropology at the master's level.  There are no full time forensic anthropologists in Canada, so when skeletal remains are found, typically the police consult a physical anthropologist with a specialty in skeletal biology.  Almost all physical anthropologists in Canada teach at universities; others work in museums such as the Canadian Museum of Civilization in Ottawa (http://www.civilization.ca/).  Forensic anthropologists in Canada belong to the Canadian Association of Physical Anthropology (http://capa.fenali.net/)and, in many cases, to the Canadian Society of Forensic Sciences (http://www.csfs.ca/csfs_journal.aspx).  In the United States, the employment situation is similar.  However, there is also a professional organization to which physical anthropologists working in the forensic anthropology field can belong, the American Board of Forensic Anthropology  (www.csuchico.edu/anth/ABFA/).
Much of the work for forensic anthropologists today is in the area of human rights work with organizations like Physicians for Human Rights (http://physiciansforhumanrights.org/).  Another human rights organization is CIFA, the Center for International Forensic Assistance (www.cifa.ac/); it employs forensic scientists from all fields to do work when needed. Something like this would provide great field experience for an up-and-coming anthropologist. 




http://people.stu.ca/~mclaugh/specialties/forensic_anthropology.html

Anthropology Saluki Style

Anthropology Saluki Style

Here’s where I do my civic duty as an anthropology major and “talk up” the Anthro Department here at SIU. First and foremost, “talking up” the Anthropology department is probably not the best choice of words to start out my post largely because the SIU-C Anthropology doesn’t need talking up….it speaks for itself.

What is Anthropology?
“Anthropology is the study of humans and their cultures in the broadest sense. It is the study of humanity, past and present, in all its biological and cultural aspects. Anthropologists study the diversity, origins, and evolution of human and primate culture and behavior, the development of human culture and the processes of culture change, the phenomenon of language, and the structure and meaning of human interaction.”                                                                                                                   -Southern Illinois University- Carbondale, Department of Anthropology Website

Anthropology at SIU-C

The SIU-C Anthropology Department is divided up according to the four field holistic approach of American Anthropology- Linguistic, Biological (Physical), Socio-cultural, and Archaeology. Ourdepartment also offers several field schools where aspiring anthropologists can gain real-life experience conducting archaeological excavations hosted by professors and researchers, ethnographic field schools where students can gain experiences visiting and conducting research with another culture, and research opportunities with professors and other students here at the university.   **Quick note- SIU-C has the only Forensic Anthropology Minor in the state of Illinois!**
My Experiences as an Anthropology Major:

As an undergraduate I have taken a broad range of classes that have expanded not only my knowledge but my worldview and outlook on life. Courses in anthropology have challenged me to reaffirm my values and beliefs as well as expand my knowledge base of human origins, histories, behavior, and present day social constructs.
I hope to become a socio-cultural anthropologist studying religiosity in the military. Although SIU-C doesn’t have strong roots in socio-cultural anthropology its roots in biological anthropology and archaeology are above par. If you are looking for a major that will allow you to play in the dirt, play with the bones of primates…including humans, challenge your beliefs, and allow you to have a blast while doing it then anthropology is what you seek.
I began my SIU career as an Agriculture Education major but quickly found out I wasn’t in the right field. After taking the course America’s Diverse Cultures I knew that Anthropology was my fate. The course material was interesting, the instructor, a PhD student, was VERY knowledgeable and hooked my interest from day one; this course remains one of my favorites out of the over 190 credit hours I have taken as an undergraduate. Anthropology is not for everyone and for my career’s sake I hope not everyone chooses to be an anthropology major BUT I hope that I have given you insight on what anthropology is and the caliber of the program we have here at SIU-C.

What is Anthropology?
“Anthropology is the study of humans and their cultures in the broadest sense. It is the study of humanity, past and present, in all its biological and cultural aspects. Anthropologists study the diversity, origins, and evolution of human and primate culture and behavior, the development of human culture and the processes of culture change, the phenomenon of language, and the structure and meaning of human interaction.”                                                                                                                   -Southern Illinois University- Carbondale, Department of Anthropology Website
Anthropology at SIU-C
The SIU-C Anthropology Department is divided up according to the four field holistic approach of American Anthropology- Linguistic, Biological (Physical), Socio-cultural, and Archaeology. Our department also offers several field schools where aspiring anthropologists can gain real-life experience conducting archaeological excavations hosted by professors and researchers, ethnographic field schools where students can gain experiences visiting and conducting research with another culture, and research opportunities with professors and other students here at the university.
My Experiences as an Anthropology Major:
As an undergraduate I have taken a broad range of classes that have expanded not only my knowledge but my worldview and outlook on life. Courses in anthropology have challenged me to reaffirm my values and beliefs as well as expand my knowledge base of human origins, histories, behavior, and present day social constructs.
I hope to become a socio-cultural anthropologist studying religiosity in the military. Although SIU-C doesn’t have strong roots in socio-cultural anthropology its roots in biological anthropology and archaeology are above par. If you are looking for a major that will allow you to play in the dirt, play with the bones of primates…including humans, challenge your beliefs, and allow you to have a blast while doing it then anthropology is what you seek.
I began my SIU career as an Agriculture Education major but quickly found out I wasn’t in the right field. After taking the course America’s Diverse Cultures I knew that Anthropology was my fate. The course material was interesting, the instructor, a PhD student, was VERY knowledgeable and hooked my interest from day one; this course remains one of my favorites out of the over 190 credit hours I have taken as an undergraduate. Anthropology is not for everyone and for my career’s sake I hope not everyone chooses to be an anthropology major BUT I hope that I have given you insight on what anthropology is and the caliber of the program we have here at SIU-C.




http://anthony.siuc.edu/2011/03/anthropology-saluki-style/

Anthropology

Anthropology is a science of humankind. It studies all facets of society and culture. It studies tools, techniques, traditions, language, beliefs, kinships, values, social institutions, economic mechanisms, cravings for beauty and art, struggles for prestige. It describes the impact of humans on other humans. With the exception of the Physicial Anthropology discipline, Anthropology focuses on human characteristics generated and propogated by humans themselves.
Physical Anthropology studies anatomy and biology -- race, gender, adaptation. It studies humankind as a biology type, describing physical development over the millenia.
Linguistics studies the structures of language and historic relationships among them.
Ethnology studies human culture in a historic and comparative perspective. There is a subfield that concentrates on myth, music, and folklore to study human geography and human passage in time.
Applied Anthropology uses anthropological knowledge and expertise to deal with modern problems. For example, it aids in impact studies of technological innovations, public health schemes, or economic development patterns. Applied Physical Anthropology can be important in the design of work stations, cockpits, airplane seats.
It is our hope that the Web pages at this site lead you to projects and studies of humankind. There are pages which can lead you to reference material, academic departments, libraries, museums, publications, organizations, and other endeavors.

BlackBerry PlayBook teardown

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BlackBerry PlayBook Teardown

With its BlackBerry PlayBook, Research in Motion joins the growing tablet market and sets its sights on the Apple iPad 2 and Motorola XOOM. TechRepublic's Jason Hiner was one hand at the PlayBook launch event and snagged one for us to test and crack open. Follow along as we take a peak at the hardware inside RIM's tablet.

Photo by: Bill Detwiler / TechRepublic
Caption by: Bill Detwiler

BlackBerry PlayBook Teardown - Image 1 of 80

With its BlackBerry PlayBook, Research in Motion joins the growing tablet market and sets its sights on the Apple iPad 2 and Motorola XOOM. TechRepublic's Jason Hiner was one hand at the PlayBook launch event and snagged one for us to test and crack open. Follow along as we take a peak at the hardware inside RIM's tablet.


http://www.techrepublic.com/photos/blackberry-playbook-teardown/6220365?tag=mantle_skin;landing

Elephant Information

 

Trunk
The elephant's nose and upper lip are elongated into a muscular, powerful trunk. This truly multi-purpose tool is powerful enough to uproot trees but dextrous enough that the two 'fingers' at its tip can pick up single seeds. Elephants can swim considerable distances and, in deeper water, will use their trunks like snorkels.

Tusks
The tusks are elongated upper incisor teeth and are not necessarily the same size. Some adults lack tusks and some have only one. Bulls typically have thicker, heavier tusks than females. Elephants will often uproot trees and then use their tusks to chisel the bark off.
Eyes and Ears
An elephant's eyes are small relative to the huge size of the animal. The ears are very large, flat and roughly the shape of the African continent, often with tears and holes in them. The ears are laden with blood vessels and when flapped, help bring down the huge beast's body temperature.
Feet and Tail
The front feet are roughly circular, with five blunt toenails; the hind feet are oval, with four blunt toenails. The soles are padded, allowing amazingly silent movement for such a large amimal. The tail is thin, up to 1.5 m long, and has a whisk of long, thick hairs at the end.
Visible Male/Female Differences
Females have one pair of mammae, low on the sides of the chest, just behind the forelegs. Both sexes have a thick flap of skin hanging between their hind legs. Males are larger, taller and twice as heavy as cows. Bulls have wider heads and in profile they have a more rounded forehead.
Diet
Very unselective; when browsing acacias they swallow more wood than leaves. In summer, grass forms the bulk of the diet, replaced in winter by woody plants. Intake is about 150kg wet weight per day while water intake is 120 litres a day for an adult bull.
Reproduction
Single calves weighing 120kg are born throughout the year after a gestation of 22 months. Calves are weaned at 3-8 years, just before the birth of the next calf.
Sounds
Elephants are very vocal, producing a wide variety of squeals, screams and high-pitched trumpeting which are audible to humans. Seventy-five percent of the vocal communication uses frequencies too low for humans to hear.
Above information from The Ultimate Field Guide and other African mammal field guides.
If you'd like to find out more about how elephants communicate, you should read this in-depth yet fascinating academic paper

Read more: http://www.wildlife-pictures-online.com/elephant-information.html

Quality of Light

The quality of light is often described in terms of hard or soft light. These terms may seem a bit nebulous. If you tell a non-photographer that you took a picture in soft light, she will probably have no idea what you are talking about. Actually, there is a somewhat objective way to view hard and soft light. Hard and soft light can be characterized in terms of contrast, shadow detail, and dynamic range. In addition, although less objective, hard and soft light can be characterized in terms of the emotional response that each tends to create in the viewer.

Quality of Light: Hard

Figure 7: Hard Light

Hard light is a very direct, harsh, often unflattering light.
Figure 7 is an example of hard light. This image was shot in the desert under the mid-day sun. The result is a rather unflattering image. The sunlit earth is very bright and the shadows hold little or no visible detail. This image may be of interest to someone who is interested in old cars or car remains, but it would not hold the interest of most other people.
Hard light has a very high contrast. This can be seen very well in Figure 7. The dirt in the sunlight is very bright almost to the point of being uncomfortable. The dirt that is in shadow is very dark. Furthermore, the dividing line between the sunlit and shadow areas is very sharp, almost knife like. At no point in this image is there a smooth transition from light to shadow. The changes are all abrupt.
Hard light tends to lack shadow detail. As can be seen in Figure 7, it is very hard to see any detail in the shadow areas under this hard light. One could bring out the shadow detail with some extra exposure, but that would make the sunlit dirt even brighter. This lack of shadow detail is related to the large dynamic range of hard light. Dynamic range is a measure of the span of tonal values over which a device (in this case a camera) can hold detail. In other words, it is the tonal distance from the darkest point at which the device holds detail to the lightest point. Dynamic range is measured in stops of light. When light is increased by one stop, the amount of light is doubled. (going in the other direction, it is cut in half). Color print film and the better digital cameras have a dynamic range of about five or so stops. That means that the brightest areas in which they can hold detail are about 32 times brighter than the darkest areas that hold detail (each stop is a doubling of light, so five stops = 2 X 2 X 2 X 2 X 2 = 32). Color slide film only has about three stops of dynamic range. Unfortunately, an environment illuminated by hard light can have ten or more stops of dynamic range. In other words, your camera can not capture all of the detail (unless you are shooting with black and white film some of which can have a dynamic range of around ten stops). In hard light conditions, either the highlights or shadows will likely lose detail when photographed in color. Generally, experienced photographers prefer to lose detail in the shadows rather than the highlights -- thus, the lack of detail in the shadows in hard light conditions.
Hard light generally creates feelings of harshness or starkness. Often, this is an uncomfortable feeling. This can work to the detriment of the photographer. For instance, a beautiful flower shot in hard light conditions will not look very attractive. Part of this is due to the harsh contrast and dark shadows. Another factor is the fact that hard light generally tends to desaturate colors. So, in addition, the flower will have washed out colors.

Figure 8: Hard Light

However, this does not mean that hard light should never be used. Hard light has its place. Hard light can be used to emphasize harshness or starkness. For instance, a photographer may choose to shoot a desert scene in hard light in order to emphasize the harsh nature of the environment. Figure 8 is a case where the photographer deliberately chose hard light to accentuate this desert grave and its harsh environment.
Hard light is created when a scene is illuminated by a small light source. Direct mid-day sun is a typical example. While the sun may be very large, it is also very far away and appears to be small to a person on earth. Thus, direct sunlight that is not filtered or reflected in any way tends to be hard. As a result, photographs taken in clear sky conditions during the day will exhibit the typical traits of hard light.

Color and Saturation

There is another aspect of color that is important to the photographer: saturation. From the photographer's point of view, saturation refers to the intensity of the color. A color that is very vivid is a saturated color. Colors that appear dull or washed out are unsaturated colors. From a technical viewpoint, saturation refers to how much white light is mixed in with the color. Saturated colors contain very little or no white light. That is why they are very vivid. Unsaturated colors have been diluted by the addition of white light.

Figure 4: Saturated Colors

Figure 4 shows an image with saturated colors. The colors are fairly vivid and pleasing to the eye. In particular, the reds, oranges, and yellows of the leaf stand out. The objects in the image are actually rather mundane; it is the saturated colors that define this image.

Figure 5: Desaturated Colors

Figure 5 shows what an image with desaturated colors looks like. In particular, the greens of the grass and bushes are relatively washed out. This is a result of the image being shot in unfavorable light (yes, I know better, but I was hiking through this area at mid day and decided to take an "I was here, too" shot).
Since color affects the mood and impact of an image, saturation becomes important. Often, photographers want rich, intense colors. Sunsets are an example of this. The best sunset images contain very saturated colors. Therefore, photographers need to understand what factors can be used to control saturation.

One of the biggest factors that affects saturation is time of day. Early morning and late afternoon generally provide more saturated colors than mid-day. If you look at the landscapes of some of the most successful photographers, you will find that most of their images were taken early or late in the day, partly, for this reason.
A polarizer filter is another way that can be used, in many situations, to increase the saturation of colors. Part of the light that dilutes saturation is polarized light. Polarized light is light that vibrates only in one direction (this has to do with the electromagnetic waves of which light is composed). A polarizer can reduce the amount of polarized light and improve the saturation of the colors. However, a polarizer is not equally effective under all circumstances. A polarizer has the greatest affect when the camera is pointed at right angles (perpendicular) to the direction of the sunlight.

Figure 6: Optimum Polarizer Angle

Figure 6 shows the optimum positioning of the camera, in relation to the object to be photographed and the sun, for the maximum polarizer effect. As the camera moves away from this perpendicular position, the affect of the polarizer is reduced. If the light is coming directly from behind or in front of the camera lens, the polarizer will have no affect at all.
Polarizers can cause problems with wide angle shots. With wide angle lenses, the angle from the camera to the objects changes, relative to the direction of the sunlight, depending on where the object is located in the wide field of view. Thus, the polarizer will have a different affect on different parts of the wide angle image. A typical example of this is a wide angle shot of a landscape where a polarizer was used. The saturation of the blue in the sky may change across the sky due to this polarizer affect.
Another factor that can affect saturation is exposure. An image may get different amounts of saturation depending on how much exposure is given. For instance, photographers that use slide film often underexpose by about a half stop to increase the saturation of the image. The affect that exposure has on saturation varies depending on what film/sensor is used, the color, and other factors. This makes it difficult to predict the impact that changes in exposure will have on saturation. The best advice is to bracket the exposures. Then, pick the best image from the bracketed exposures.

http://www.ronbigelow.com/articles/light/light.htm

The nature of light

Article and Photography by Ron Bigelow

www.ronbigelow.com

It is very instructive to take note of what issues top photographers tend to write and talk about. For these are likely the issues that these photographers consider critical to their success. This being the case, the one topic that I see covered by top photographers, time and again, is the topic of light. The nature photographers often talk about seeking out certain light conditions or only shooting in specific types of light. The portrait specialists often discuss the lighting set ups and how it affects the final image. Even the photojournalists and travel photographers talk about trying to catch people in light conditions that best exemplify the people and the environments in which they live.
If light and its qualities are so important to top photographers, it would behoove us to examine light and understand its influence on our photography. Therefore, the purpose of this article is to look at light, its characteristics, and how it influences our images.

The Triple Nature of Light

Knowledgeable photographers will tell you that light has a triple nature for the photographer: color, direction, and quality. It is these characteristics of light that determine how our images turn out. It is an understanding and mastery of these characteristics that is often, at least partly, responsible for the best images that we see.

Color of Light

In 1665, Sir Isaac Newton was able to show, by using a double prism experiment, that ordinary, visible light is actually composed of seven colors (red, orange, yellow, green, blue, indigo, and violet). We now know that visible light is actually a continuous color distribution that starts with red light at the long wavelength end of the spectrum (wavelength has to do with the electromagnetic properties of light and refers to the distance from one crest of the electromagnetic wave to the next; if that doesn't make sense, don't worry about it) and ends with violet at the short end. In reality, visible light is only a portion of the light spectrum (light continues with infrared at one end of the spectrum and ultraviolet at the other).
Pure, white light is composed of a balance of these colors. However, light is not always pure. Often, the color balance of the light has been altered. Most frequently, this occurs because one or more of the colors have been, at least partially, filtered out of the light. When this happens, the color of the light changes. Because of this, the light that we experience is constantly changing color all day long and this affects the color balance of the images that we take. As covered in my article on advanced composition (Advanced Composition -- Part II) color affects the mood of an image. Consequently, the color of the light that illuminates a scene will impact the mood of the image and its ability to impart what the photographer wanted to communicate to the viewer of the final image. This works to great advantage for the knowledgeable photographer that uses her knowledge of light color to capture images where the color of the light is in harmony with the mood that the photographer wishes to create in the image. Conversely, the light often works to the detriment of the less knowledgeable photographer to contradict the mood that he intended to create or, at best, leaves him with an occasional, lucky image that impresses his friends but which he can not replicate due to his lack of understanding of the effect of the light on the emotional impact of the image.
Luckily, for photographers, we can simplify the color of light down to three basic categories of color: neutral light (no strong hue), warm light (tinted with yellow, orange, and red), and cool light (tinted with blue). We can simplify color down to these three categories because each of these categories has a different effect on how people respond to an image.

Figure 1: Neutral Light

Neutral light, which has no strong hue, is best used when a photographer wants the natural color of the objects to shine forth.
Figure 1 shows an image that was taken under fairly neutral light conditions. Under these conditions, the light did not add any significant colorcast to the image. This was desirable in this wave image. The white of the foam is critical to this image, and it was necessary to capture this white without any hue being introduced by the light. The use of neutral light allowed this to be done.
Neutral light is found away from both ends of the day (not in very early morning or in late afternoon). Light from a direct, overhead sun on a clear day may have a fairly neutral color. Photographers that wish to use neutral light need to beware of certain conditions. Heavy cloud cover will likely shift the color of the light toward blue. Also, shadows generally have a bluish tint. Light that is filtered or reflected in any way may pick up a hue. For instance, a photographer standing in a forest will likely find that the light has picked up a green hue from the leaves overhead. A photographer in a canyon with light reflected off the canyon walls will likely find that the light has picked up a color from the walls (probably a warm tone).
Warm light is good for creating inviting, dreamy moods in an image. People tend to associate warm light with feelings of comfort, friendship, and romance. The roaring fireplace that two lovers sit by casts a warm light on them. A husband and wife celebrating their anniversary eat dinner at a table illuminated by the warm, flickering light of a candle.

Figure 2: Warm Light

Figure 2 shows an image that was taken under conditions of warm light. At the time this image was taken, the sun had dropped low on the horizon and the light had developed a warm tone. This warm tone is most noticeable on the face of the cliff with the waterfall. The warm light gave the scene a gentle, enticing mood. The importance of the color of the light used to create this image can not be over emphasized. The waterfall in this image is the McWay Falls in Big Sur, CA. It is reported to be one of the most photographed waterfalls in the state. I have seen images of this waterfall from several professional photographers, and every single one of those images was taken in warm light conditions. In other words, for this and many other successful images, having the correct color of light is not something that is desirable; it is something that is mandatory.
Warm light is best found just after sunrise or just before sunset. This is because of the interaction of light and air molecules. Air molecules scatter the short wavelength blue light more than the long wavelength red light. Just after sunrise and before sunset, the sun is low on the horizon. This causes the sunlight to travel through more of the thicker air near the earth (the air gets thinner the higher one goes in the atmosphere). As a result, much of the blue part of the light is scattered. This leaves a warm light.
While the warmest light will generally occur within about a half hour of sunrise and sunset, the light can, sometimes, begin to pick up a warm tone a couple of hours before sunset (my experience has been that the light tends to lose its warm tone fairly quickly after the first half hour of sunlight in the morning). My experience is also that the late afternoon tends to produce warmer light than in the morning. Photographers that wish to use warm light need to watch out for clouds and shadows; both produce a bluish light.
Cool toned light is good for creating feelings of calm or cold. People tend to think of deep, calm lakes as being blue. A calm sky is usually blue. On the other hand, people also tend to associate blue with cold: ice may have a blue tint as well as the light of an early, winter morning.

Figure 3: Mixed Cool and Warm Light

Figure 3 illustrates the use of cool light. Actually, this image illustrates a mixture of light. The clouds low on the horizon display the very warm light of the last few rays of sunlight. However, the ocean has already fallen into the shadow of evening. The ocean is dimly lit by the sky above that has cast a cold, blue calm over the ocean. This contrast of light adds impact to the image. This image represents the dividing line of the day: the warm of the sun departing as the cold, ocean wind begins to chill the night air.
Cool light can often be found in the time between the first light of day and sunrise as well as between sunset and darkness. These twilight times often cast a soft, dim, bluish light over the terrain. Sometimes, a mixture of light is created at these times (as in Figure 3). Blue light can also be found under cloudy skies and in shadows.
Cool blue light is caused by the same phenomenon that causes warm light. Remember a few paragraphs back it was stated that the air molecules scatter the cool, blue light more than the warm, red light. This explained why the light just after sunrise and before sunset was warm, but what happened to all that blue light that was scattered? It was scattered into the sky. This is why the sky is blue. It is due to the scattering of the blue part of the light spectrum (this scattering happens all day long; it is just more pronounced during the very early and very late portions of the day).
During the twilight times, the sun is below the horizon. The landscape is illuminated by the sky alone. The light from the sky has a blue tint due to the scattered, blue light. This is also why the shadows are blue as they get most of their light from the sky rather than light directly from the sun.

Cuba: The Accidental Eden

Photos: Snails of Cuba

Cuba, an isolated paradise at the confluence of the Gulf of Mexico, Caribbean Sea, and Atlantic Ocean, provides a fertile laboratory in which biologists can observe and study unique creatures in unspoiled habitats.

Cuba is known as the “Paradise of Snails.” The beautiful “painted snails” or land snails of Cuba, called Polymita, are a snail species that occupy large, brightly colored and highly sought after shells.

Polymita have a wide array of color varieties and markings.

With eyes perched on long stalks, Polymita seek out water and lichen on the leaves of ferns and other plants.

Polymita are hermaphrodites, both male and female, which means that anyone is a potential partner. This sexual characteristic has grown increasingly more important as populations are put at risk by poachers and growing tobacco farms.

They use their brightly colored, swirled shells to attract potential mates. These two painted snails are engaging in a mating ritual, a mysterious dance which begins as the couple slowly circles one another.

Polymita extend a piercing weapon, known as a “love dart” to puncture one another in the so-called "sensitive zone," until they successfully exchange sperm. After the mating ritual has concluded, they linger for a short while and slowly part, both going on to lay fertilized eggs.

What once served as Polymita’s elegant armor now puts them in danger of their greatest threat yet. Poachers hunt them to sell as shell necklaces and trinkets, and the snails are now endangered.

The red valleys of Viñales provide more than fertile soil; they also provide an evolutionary microcosm for the study of the painted snail. Erosion-carved limestone faces provide an environment, like the Galapagos, that allows snails to undergo evolutionary forces in isolation. The snails here never venture more than 60 feet from their home. The shape, color, and behavior of these snails are therefore dictated by the land.

Each slope of the behemoth limestone karsts, called mogotes, has its own species and different variations of snails which all belong to the same species. Depending on the slightly different environments, humidity, wind resistance, and available nutrition differ, which results in a relatively large diversity of forms in a very small area.

The bistec de mogote, or “pancake slug” is an example of evolutionary adaptation in Cuba. The snail traded its shell for a different defense: it’s perfectly camouflaged to disappear into the crevices of the limestone rock face. Still, they are losing habitat to expanding tobacco farms, and many are hunted for much-needed protein.

http://www.pbs.org/wnet/nature/episodes/cuba-the-accidental-eden/photos-snails-of-cuba/5788/

CORAL REEFS

CORAL REEFS

Coral reefs are the most diverse and beautiful of all marine habitats. Large wave resistant structures have accumulated from the slow growth of corals. The development of these structures is aided by algae that are symbiotic with reef-building corals, known as zooxanthellae. Coralline algae, sponges, and other organisms, combined with a number of cementation processes also contribute to reef growth.
The dominant organisms are known as framework builders, because they provide the matrix for the growing reef. Corals and coralline algae precipitate calcium carbonate, whereas the framework- building sponges may also precipitate silica. Most of these organisms are colonial, and the slow process of precipitation moves the living surface layer of the reef upward and seaward.
The reef is topographically complex. Much like a rain forest, it has many strata and areas of strong shade, cast by the overtowering coral colonies. Because of the complexity, thousands of species of fish and invertebrates live in association with reefs, which are by far our richest marine habitats. In Caribbean reefs, for example, several hundred species of colonial invertebrates can be found living on the undersides of platy corals. It is not unusual for a reef to have several hundred species of snails, sixty species of corals, and several hundred species of fish. Of all ocean habitats, reefs seem to have the greatest development of complex symbiotic associations.

Branching and Mound-Shaped Corals

Photo by Phil Dustan
Reef-building corals may occur in a variety of growth forms, and there often is strong variation in coral shape even within a species. In this photograph, we can see the branching elkhorn coral Acropora palmata (upper left), with arms showing strong orientation into an oscillatory current between left and right. In the right foreground is the mound-shaped coral Montastrea annularis. It is of great interest that such differently shaped corals can occur side by side. What might that indicate to you?

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Intraspecific Variation in Growth Form

Here is an intraspecific example of variation in growth. We see two colonies of Montastrea annularis, but one (center) is platy in appearance, whereas the other (right) is more mound-shaped.

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Deeper Water form of "Monastrea annularis"

Photo by Phil Dustan
In deeper waters (ca. 30 m) in the reefs of the north coast of Jamaica, one finds a greatly flattened species of Montastrea, which is a very close relative of the mound-building shallow water Montastrea annularis. The flattened mushroom-like shape may be an adaptation to capture light efficiently.

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Plate-like Growth of Agaricia sp.

Photo by Phil Dustan
By contrast, species of Agaricia tend to be plate-like in form and do not display nearly as much variation as some other dominant corals on the reef. A large fauna of sponges, bryozoans, articulate brachiopods, and other sessile epibenthic invertebrates live on the undersides of these platy corals.

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Oriented Branches of the Elkhorn Coral

Photo by Phil Dustan
Here we see the occurrence of a group of colonies of the elkhorn coral Acropora palmata, with arms conspicuously oriented left to right. This probably reflects a predictably strong bidirectional current. Because of the extensive growth plasticity of some corals, it is often difficult to distinguish between distinct biological species and plasticity of form within a species.

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Platy Form of the Elkhorn Coral

Dancing Lady Relief, Jamaica

Photo by Phil Dustan
This shot of a reef on the north coast of Jamaica vividly captures the large amount of shade cast by the dominant elkhorn coral Acropora palmata. Because reef-building corals depend upon zooxanthellae for colony growth, the shaded areas are not good areas for vigorous coral growth, which depends upon light.

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Hexacoral Polyps, Closeup

Photo by Robert Richmond
Hexacoral polyps (e.g., stony corals) have tentacles in groups of six. In hermatypic - or reef-building - corals symbiotic zooxanthellae are found within the endoderm and are usually concentrated in the tentacles, which increases exposure to light. The tentacles are also the site of enormous numbers of nematocysts, which can ensnare or puncture prey.

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Polyps of Montastrea cavernosa

Photo by James W. Porter
This is a closeup of the massive scleractinian coral Montastrea cavernosa. The tentacles capture smaller zooplankton, by means of nematocysts.

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Octocoral Polyps

Photo by Robert Richmond
Octocoral polyps (e.g., sea whips, sea fans) have 8 tentacles, instead of 6. Particles such as smaller zooplankton are probably captured by direct interception on the tentacles. In some cases, such as in sea fans, water streams around the colony and polyps capture particles in the quiet eddies that are formed on the downstream side of the colony.

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Crown-of-Thorns Starfish, Acanthaster planci

Photo by Robert Richmond
Acanthaster planci is a carnivorous asteroid starfish whose principal prey are corals. It has sharp dorsal spines that penetrate human skin and cause sickness. Normally it occurs at low density and is nocturnal. In the 1960s, population explosions were found all over the Indo-Pacific and the starfish were moving in large numbers during the day. Instead of being of minor impact, they were now major predators on the reef. In Guam, for example, over 90% of the corals were killed. The explanation of the origin of the outbreaks is still very controversial. Charles Birkland suggested that they were related to storms that could wash out nutrients from atolls, which stimulated phytoplankton grown, which, in turn, increased the survival of starfish planktotrophic larvae. Others have argued that larval starvation is not a limiting factor in larval survival. It was also argued that typhoons and other storms killed corals, causing starvation among the starfish and a switch to roving in aggregations in search of food.
Pacific shallow reefs are often dominated by the the erect coral Pocillopora damicornis. When the crown-of-thorns starfish tries to mount and consume the coral, several species of shrimps and crabs that live among the coral branches move to attack the starfish, thus defending the coral.

plant growth facilities

Botany's eight greenhouses, encompassing 8,000 square feet, are located north of University Avenue and bounded by Chamberlain, Lathrop and Birge Halls. The facility features more than 1,000 species and aquatic, desert and tropical communities. Botany and other UW departments make extensive use of this working facility, permitting faculty and students to undertake a variety of research projects in plant geography, physiology, anatomy, ecology, taxonomy and other related areas.

The Botanical Garden serves both teaching and research as a living reference for plant families, genera and species. Examples of plants from around the world demonstrate the diversity and beauty of the plant kingdom. This is the first garden in the world to be designed based on the new Angiosperm Phylogeny Group (APGII) system of molecular classification of plants.

 
LEFT: Little Stinker, a rare Amorphophallus titanum, blooms in Greenhouse number 8.
RIGHT: The Botanical Garden with Birge Hall and Greenhouses in the background.
INSETS: A silver-spotted skipper enjoys a lobelia; the shade garden features over 100 lily varieties.

In addition to meeting essential teaching and research interests, the greenhouses and garden are an aesthetic resource for students and the community. Botany staff assist visitors seeking advice on plants for their homes and gardens, and touring school children gather the seeds of environmental stewardship.

Comments, Questions, Desire to Support: Contact Mo Fayyaz, Greenhouse/Garden Director, 608 262 2235.

Marine Science

Marine Science is a well-rounded and multi-disciplinary program which has been carefully designed to take full advantage of the unique variety of marine environments available for study around the island of Hawaiʻi. Introductory lecture and laboratory courses in general oceanography and marine biology are followed by intermediate-level courses in marine ecology, marine monitoring techniques, and statistical applications in marine science. The most advanced level of the program is composed of specialized courses in geological, chemical, physical, and biological oceanography. The program culminates in a student’s choice of one of three capstone sequences: (a) Senior Thesis, a research sequence involving proposal writing, library research, field data collection, laboratory work, computer analysis of data, report writing, and oral presentation; (b) Senior Internship, a sequence providing students the opportunity to apply their knowledge and skills in an agency or organization involved in marine science education or research; or (c) Senior Seminar, a sequence involving discussion, critique, and presentation of marine science-oriented seminars, and grant proposal writing.

Goodbye Firefox. Hello Chromium.

After using Firefox for six years, I’ve finally come to the end of the road with it. Learn why, as well as why I chose Chromium to replace it as my primary Web browser.
My relationship with Firefox has been on the rocks for a while. It officially ended this week. Time to move on.
While Firefox started out as a small, fast, and secure browser — everything that Internet Explorer wasn’t back in 2004 — in the last several years Firefox has unfortunately become a bit of a slow, bloated, resource hog. Nevertheless, since I’ve been such a long-time Firefox user, I’ve been hanging on and waiting for the final release of Firefox 4, hoping that would give the ‘fox some new life.
After using Firefox 4 for less than a week, it’s clear to me that Mozilla hasn’t fixed the speed issues or the resource problems, and I’ve finally reached the point where I’m tired of fighting with Firefox. I’m tired of constantly looking at my open processes to see what’s bogging down my system and virtually every time it turns out to be Firefox.
The situation finally came to a head on Monday and Tuesday of this week when both cores of the CPU on my system were at 80% for big chunks of the day on both days, and the culprit was, naturally, my newly-installed Firefox 4. The clincher was when I took all of the tabs that I had open in Firefox (about 10 of them) and copied and pasted the URLs from Firefox into Chromium. Then, I closed down Firefox. The CPU utilization immediately dropped under 20% and everything on the system started running at normal speeds again.

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I used Chromium all day on Wednesday as my primary Web browser for all of my TechRepublic tasks — content management, blogging, selecting articles for our front door, creating photo galleries, running reports, and doing Web research. Chromium performed like a champ, opening most pages faster than Firefox and never bogging down the processor except for two occasions when I played large videos.
I’m sure some of you are asking, “What’s Chromium?” or “Why Chromium instead of Google Chrome?” Chromium is the open source project that serves as the foundation for Google Chrome. Think of Chromium as the bleeding edge version of Chrome created by the open source community. However, Chromium is not for everyone. It’s not nearly as polished or bug-free as Chrome, and while Chrome silently updates itself in the background, Chromium has to be updated manually (and there a new builds available almost every day). The process of updating to the latest build of Chromium is made easier by tools such as Chromium Updater.
However, my biggest motivation for choosing Chromium over Chrome is security. While Google promises that Chrome isn’t reporting back to Google with any additional data about your browsing habits — at last no more than any other Web browser — I don’t completely trust Google in that regard. The company has too much to benefit from gathering as much data as possible from every single user. Because Chromium is open source, if there was any kind of supposedly-harmless data collection going on, the open source coders would likely spot it and alert the community and the public. That, and the extra speed boost from running the cutting edge software builds, are what led me to Chromium.
I had been using Firefox as my primary Web browser for six years. That’s certainly the longest I’ve ever stuck with a single browser — I was on Netscape and then IE for 3-4 years each before jumping to Firefox in late 2004. Still, I’m not going to be uninstalling Firefox. I’ll keep it around for occasional testing — especially for new TechRepublic features. But, I don’t see much chance of it regaining its spot as my primary Web browser.

The About pages for Chromium and Chrome show the open source roots and legacy behind Chromium.

http://www.techrepublic.com/blog/hiner/goodbye-firefox-hello-chromium/8085