jmalloldiaz's blog

On page 28 there are two sets of three pictures displaying different parts of a tree. Assuming that the top row of pictures was taken independently, and that the bottom row of pictures tried to replicate the original set, we can infer different facts. The first inference is that the person who took the original set of pictures wrote as well a description of how they were obtained, and the second person followed this set of instructions to produce his photographs. We can infer this because both sets of pictures look very similar, and if someone had the task to photograph a tree they could have gone to any tree, but in this case all the pictures show the same tree and the same areas of it.

We can infer as well that the two sets of pictures were taken with different cameras or filters, since the bottom row has different lightning than the top row, which could be due to a failure to explicitly explain to use the normal set up of the camera or a specific model of photographic device. It can be inferred as well that the sets of pictures were probably taken at different times of the day, although with no major differences in timing, because the position of the light falling over the sap in the middle picture changes slighlty between rows.

Looking at picture b in the top and bottom row, we can notice that the top row is clearly focused on the trunk of the tree and there is no background, while in the bottom row there is a little bit of background on the left and more space of the tree can be appreciated. From these observations we can infer that the second person took this picture further away from the tree than the first person, or that the first person zoomed in closer to the tree trunk than the second person.

Regarding the format of the figures, the top row of pictures has white letters in black boxes placed on the upper left corner of each image. While the bottom row of pictures has also black boxes with letters on the upper left corner of each image, the size of the letters is much smalller, and the placement of the boxes shifts slightly out of frame for the left and right pictures. As well, the spacing between pictures differs between the top and bottom rows, the top one having bigger pictures with less space in-between. From these observations we can infer that in the description of the methods of the first person there were no specifications regarding letter size or spacing, but there were mentions to using specific letters for labelling each picture, as well as using black boxes on the top left corners and white color for the letters.

On page 28 there are two sets of three pictures displaying different parts of a tree. Assuming that the top row of pictures was taken independently, and that the bottom row of pictures tried to replicate the original set, we can infer different facts. The first inference is that the person who took the original set of pictures wrote as well a description of how they were obtained, and the second person followed this set of instructions to produce his photographs. We can infer this because both sets of pictures look very similar, and if someone had the task to photograph a tree they could have gone to any tree, but in this case all the pictures show the same tree and the same areas of it. We can infer as well that the two sets of pictures were taken with different cameras or filters, since the bottom row has different lightning than the top row, which could be due to a failure to explicitly explain to use the normal set up of the camera or a specific model of photographic device. Finally, we can infer that the sets of pictures were probably taken at different times of the day, although with no major differences in timing, because the position of the light falling over the sap in the middle picture changes slighlty between rows.

Komodo dragons live in the island of Flores, in Indonesia, and apart from being one of the heaviest lizards (~ 70 kg) they are also one of the few with a venomous bite. They are usually unsuccessful in actively hunting prey, specially when trying to bring down animals much bigger than them like water buffalo (300-550 kg). Nonetheless, once a komodo dragon bites a water buffalo it is just a matter of patience and tracking down with the sense of smell, to find a few days later the carcass of the buffalo ready for feeding.

People used to think that due to their scavenging nature, Komodo dragons have deadly bacteria in their saliva from the decaying flesh on which they feed, which could eventually induce sepsis in another prey if bitten. But researchers have discovered that Komodo dragons have venom in their saliva, which is designed for exsanguination by causing blood pressure to plummet, inhibiting coagulation, and inducing shock in the victim. Still, water buffalo are too big for bleeding to death from a Komodo dragon bite injury on just flesh. On the other hand, clean water is scarce in the island of Flores, which forces the buffalo to live in warm waters swarming with bacteria that enter through the open wounds inflicted by the Komodo dragons and cause the actual sepsis that leads to their death.

Figure 1. Andean Flamingo (Phoenicoparrus andinus) in Potosi, Bolivia. Flickr photo by Sergey Pisarevskiy https://farm6.staticflickr.com/5334/9282732023_ef0c9b21d2_z_d.jpg shared under a Creative Commons (CC BY-NC-SA 2.0) license.

Previous to the appearance of modern wildlife tracking technologies, little was known about many aspects of the life histories of marine creatures, including how they use space and their migratory habits. A long-term study performed by researchers in the coast of South Africa used photographic identification data since 1997 for recording white shark activity in Gansbaai. With the development of electronic tagging devices such as acoustic tags, PAT tags, and satellite tags, the researchers were able to take their study a step further and discover where white sharks go when they are not roaming along the coast of South Africa. Among the tagged white sharks of their study, a female classified as P12 performed the fastest return migration ever recorded in a marine animal, when it traveled to Australia and back to its natal range in South Africa in less than 9 months, navigating more than 20,000 km at a minimum speed of 4.7 kilometres per hour. Although more data from individual migrations of white sharks should be recorded, this first transoceanic journey suggests a connection between two important populations in South Africa and Australia, and offers important information for conservation efforts of endangered marine fauna.

When I'm at UMass I rarely take the bus, and since I don't have a car or a bike I walk to most places. For example, yesterday over the course of the morning, I walked to all the locations where I needed to be. Early in the morning I walked to Worcester DC to have breakfast, then went back to my dorm using the same method of transportation to brush my teeth and get my backpack. Later, I walked to Morrill where I had to go up the stairs to meet with my Marine Vertebrates professor. After the meeting, I walked downstairs to my lab where I worked until lunch. Once lunch time arrived, I walked to Franklin DC to get some food before my class started.

Regarding the cephalothorax of this specimen, it seems to have two dark spots located on the top as well, which may be another set of eyes, and due to the nature of this spider they might be used simply for light detection and thus be less developed than its other sets of eyes. When we think about eyes, we tend to think about our own and asume that the rest of animals view the world in a very similar way as us. Nonetheless, there are many different kinds of eyes in nature, some more developed and complex than human eyes, others more simple and primitive. Since this specimen seems to be a cellar spider, we can asume that its habitat is mostly dark and moist, and in such environment possesing fully developed eyes capable of distinguishing shapes, features, and colors, may not be useful and actually have a great energy investment that does not compensate. Instead, maybe this species relies on other senses such as chemoreception or mechanoreception, and while some of its sets of eyes may actually have a tapetum or similar structure that allows them to see in the dark, the most probable role of the set of eyes located on top of the cephalothorax may be just perceiving subtle changes in light intensity, so that the spider has a way of telling if it is exposed to the open where it could be easily predated, or if it is instead inside a dark environment like a cellar where it has an advantage over its prey.

This specimen seems to be a male cellar spider. I think it is a male because it has huge pedipalps, most commonly found in male arachnids. Its pedipalps are about the same size as its cephalothorax, and they are transparent.

It is difficult to see the complete set of eyes of this spider, but it seems to have two tiny principal eyes, also known as AME's (anterior medial eyes) and two pairs of bigger eyes located to the sides of the AME's.

The whole body of the spider is about the size of my thumbnail, which maybe around 1 cm more or less. The color of the body, disregarding the cephalothorax which is translucid, seems to be grey and it might be just because it is transparent as well and the organs are showing.