fmillanaj's blog

Our project involves measuring the width of spiders, along with their weight to determine a possible relationship. We accomplished this by using an advanced microscope and individual spider silk. Silk was obtained from the spiders. The spiders were all in the same environment to ensure the variables were the same. Our results showed a negative trend in the relationship, with the heaviest spiders having the thinnest silk. This could be a potential sampling error, and increasing the sample size would offset this. 

The aim of this study was to determine if there is a relationship present between the body weight of spiders and silk thickness, as well as to determine the relationship between weight and thickness among various species of spiders (Pholcus phalangioides, Araneus diadematus, Nephila edulis, Latrodectus mactans, and Euprosthenops sp). We hypothesized that spider silk thickness would increase with the weight of a spider.

Exploring the various factors that contribute to differences in spider web characteristics, such as thickness, could help us learn more about the factors that contribute to their high elasticity and can be useful for the material engineering of a material that is both strong and soft. The diameter of the web is important because it provides some clue as to what the spider uses the web for. There is some variation in spider silk diameters, as well as the mechanical characterization of silk (Blackledge et. al. 2005).

In this study, three spiders were weighed at the beginning of the experiment and they spun webs for 3 days after being weighed to allow for the production of a sufficient amount of silk. After the third day, the thickness of an individual strand of silk from each web was measured using a microscope and micrometre. The measurements of weight and silk thickness were compared to data retrieved from another study (Shao, Z. Vollrath, F. 1999), in which the same variables were measured under similar conditions to determine if a relationship existed between weight and silk thickness.

The conclusions reached as a result of this experiment is that there is a negative relationship in the spider weight-silk diameter of Pholcus phalangioides. However, out data has a wide range of data and may not be conclusive. According to measurement results retrieved from another article for (Araneus diadematus, Nephila edulis, Latrodectus mactans, and Euprosthenops sp), these spiders do not have a clear pattern between weight and silk thickness. This suggests that there is no correlation between the weight of a spider and the thickness of the silk.

Several different studies described spider webs as depending upon the mechanical performance of capture threads, and states that web function arises from the architecture and mechanical performance of silk (2). This study also used microscopy, and measured the web thickness of different web types: orb webs, funnel webs, dome webs, and irregular mesh webs. The different types of webs yielded different thicknesses on average, with orb webs being the thickest. Since spider webs must be strong enough to withstand the weight of the spider on the web, and be durable enough to support the spider’s movement, it is plausible that spider weight could also be a factor in web thickness, in addition to web type.  

Glomerular Filtration occurs in the Bowmans capsule. The forces that control this filtration from the glomerulus to the Bowmans capsule are known as Starling Forces. These consist of Hydrostatic pressure of the glomerulus, Bowman's capsule oncotic pressure, Bowman's capsule hydrostatic pressure, and Glomerular oncotic pressure. The forces that work for filtration are hydrostatic pressure of the glomerulus (how much pressure is on the surface) and the Bowmans capsule oncotic pressure. The forces that work against filtration are the Bowmans hydrostatic pressure and the Glomerular oncotic pressure. 

Several different studies described spider webs as depending upon the mechanical performance of capture threads, and states that web function arises from the architecture and mechanical performance of silk (2). This study also used microscopy, and measured the web thickness of different web types: orb webs, funnel webs, dome webs, and irregular mesh webs. The different types of webs yielded different thicknesses on average, with orb webs being the thickest. Since spider webs must be strong enough to withstand the weight of the spider on the web, and be durable enough to support the spider’s movement, it is plausible that spider weight could also be a factor in web thickness, in addition to web type.  

There have been numerous studies on spider silk and silk characteristics as well as their
applications towards creating new technology. Spider silk is extremely thin, the largest silk fibers
being only 5-10 μm. Some can be as thin as only 50 nm, making spider silk very difficult to
measure. Although spider webs are very thin and flexible, they are remarkably strong. The
tensile strength of spider webs is comparable to steel, with strength as high as 1.75 GPa. (5)
Due to the small size of spider silk, there have been few studies on how its properties
can be exploited, and even replicated. A common tool used to measure spider silk is using a
microscope. In an experiment done by researchers at UCLA (1), light microscopy was used to
compare spider silk from different species. In this study, spider silk was stretched out on a
microscope slide. The silk was then measured using a micrometer to obtain its diameter. This
method was used in several different studies to measure the diameter of spider silk in different
conditions, allowing for researchers to compare each silk effectively.​

The aim of this study is to determine if there is a relationship present between spider body weight and spider silk thickness among various species. Discovering the various factors that contribute to differences in spider web characteristics, such as thickness, could help us learn more about the factors that contribute to their extreme elasticity and could be useful for material engineering of a material that is both strong and soft. Previous studies have shown that there is some variation in spider silk diameters, as well as the mechanical characterization of spider-silk. Light-microscopy is a proven method to study the differences between objects that are small, such as spider silk, and will be used in this study to measure the diameter differences. A total of two each from three different species will be obtained. These spiders will then be weighed on analytical scales after exactly four days of feeding to ensure they have the adequate nutrition to spin spider silk. The spider silk will then be measured and compared throughout the species.

Vitamin D is indicated to be lacking in my diet, for the target of 15 micrograms is not met for I only consume about 3 micrograms on average. Not getting enough vitamin D can be dangerous for it plays the role of modulating cell growth, neuromuscular and immune functions, absorption of calcium, therefore, contributing to bone growth. Deficiency not very uncommon because vitamin D is naturally not present in many foods, making it more important that we are aware of our intakes8. Given that we are entering the colder months it also is more challenging to obtain vitamin D from the sun, therefore it must be done by selecting proper foods. As mentioned before, fat-soluble vitamins are more likely to cause toxicity for it is stored in the body, therefore monitoring the intake of this vitamin is extremely important. In most extreme cases toxicity may raise blood levels of calcium, in turn leading to damage to the heart, blood vessels and kidneys8. Some of the best sources of Vitamin D are fatty fish, including salmon and tuna, both of which are foods I enjoy and will add to my diet in greater amounts to make up for the lack of Vitamin D in my diet. Beef liver, cheese, and egg yolks also contain some amounts of vitamin D.

Antagonistic control of the heart is an important element to its function. Antagonistic control in a system is when two things do the opposite job (push or pull etc..) work together to control a system (such as the heart). Specifically, the type of antagonistic control of the heart when the sympathetic nervous system acts as an antagonist with the parasympathetic nervous system. 

There are two ways that the pressure of the heart can be affected immediately. The first is by reducing the volume of the container without reducing the volume of the liquid. This causes a pressure buildup in the hearts chambers. Another is to increase the volume of the liquid without increasing the volume of the container. This also causes a pressure buildup.