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Ecological Succession

Submitted by mpetracchi on Thu, 11/07/2019 - 01:04

In ecological terms, succession is the process by which a community's composition changes over time. Succession begins in an environment where there is no life present. In such an area, a species hearty enough to survive extreme conditions must be introduced first. Once a species takes hold in this harsh environment, it becomes known as a pioneer species which launches the the area into the pioneer stage. These first species usually create changes in the area through their existence by simply carrying out their natural functions. Eventually, once pioneer species have molded the environment enough, other species begin to inhabit the area even though they may not have been able to beforehand. Overtime species will be added and removed from the community putting it in an intermediate stage. Through enough trial and error via natural selection, amongst other factors, a community may reach what is known as the climax stage. In this stage, a community is thought to be a stable endpoint where the ecosystem is harmoniously functioning. At any one of the three major stages disturbances such as fires, storms, eruptions, etc, could send the community back to any one of the earlier stages.

Photosynthesis: Dark Reactions

Submitted by mpetracchi on Thu, 11/07/2019 - 00:36

After a plant has taken in sunlight and water to produce ATP and NADPH, it has the necessary ingredients to produce a sugar molecule. First, a plant must take in CO2 to be fixed using the 5 carbon molecule Rubisco or RuBP. Carbon fixing is the process by which gaseous carbon is converted to a non-gaseous molecule. Exactly 3 CO2's and 3 RuBP's are used to produce 6 3-PGA's. The 6 3-PGA's are then are reduced using 6 ATP's and 6 NADPH's into 6 G3P molecules. One of these G3P molecules is set aside as a sugar product and the remaining 5 are used to regenerate RuBP. The product, G3P, is composed of 3 carbons, oxygen, hydrogen, and phosphorus. Regenerating RuBP requires an additional 3 ATP and the 5 leftover G3P's. Once RuBP has been regenerated it can be used to fix more CO2 and continue the dark reaction cycle.

Harappan Civ 2

Submitted by mpetracchi on Wed, 11/06/2019 - 01:40

The occupations people held determined their standing in society. Archaeologists uncovered only a few seals, which indicate it is likely that they were used by individuals or communities with considerable power, such as landowners, merchants, and religious leaders (Kenoyer). If everyone in the society were equal, then many seals would have been found because everyone would have the opportunity to have one, yet this is not the case. Instead, a select few were discovered. This implies a small group of people interacted with these items and possibly received more economic gains than others in society. Reports on early Harappan settlers say they, “seem to have exploited the rich agricultural and grazing lands along the Ravi River to sustain themselves as they built economic and political power through craft production and trade” (Kenoyer). A system of trade, or economy, is a capitalistic idea and capitalism encourages the summation of wealth, usually by individuals. Some initial settlers must have made good livings off trading goods while others not so much. Over time, as these settlers became the Harappan people we know today, it is possible wealth disparities increased amongst the population. Again, if there are disparities in wealth, there are disparities in social class and therefore a social hierarchy is present.

Harappan Civ

Submitted by mpetracchi on Wed, 11/06/2019 - 01:38

Human civilizations tend to possess similar characteristics even across religious, linguistic, spatial barriers. Civilizations such as Harappa and Sumer may appear to be completely different, and there are many reasons why they were. However, similar traits can be observed through artifacts found at these ancient sites, one of which is a social hierarchy. In general, a polarized social hierarchy develops due to power dynamics from a ruling class legitimized by another social factor. In the case of the Harappans, their social hierarchy was much less polarized than ancient Sumers and was legitimized through the economy rather than a ruling class.

    Archaeologists studying Harappan civilization in the Indus river valley have uncovered many artifacts which, I believe, show society to be a hierarchy. Some artifacts were identified as jewelry or luxury goods which were likely used by an upper class “to demonstrate their wealth and status” (Kenoyer). A society without a hierarchy implies there is little to no social stratification among the people and everyone has similar opportunities. If these luxury goods and jewels were used to demonstrate status and wealth then there must have been a disparity in wealth. Interestingly, children, commoners, or both, were found to be wearing terra-cotta items whereas members of the upper class wore exotic stones (Kenoyer). If there weren’t a disparity then demonstrating their wealth would be pointless because everyone would have had the same jewelry. However, commoners and the upper class did not have the same jewelry, likely due to a disparity in wealth. Where there are wealth disparities, there are social disparities. After some time, I believe social classes based on wealth gaps evolved in Harappan society forming a hierarchy. 


Poster review pt 2

Submitted by mpetracchi on Mon, 11/04/2019 - 01:28

The organization of this poster does not follow conventional scientific sections (abstract, introduction, methods) as it is more of a review than a study. The flow of the poster is choppy and confusing. Although there are numbered sections, it stills feels clunky when following the sections in order. The beginning of the flow is in the upper middle, then it goes left and down, then up to the middle, then down, then right, then up, then down. In my opinion, this is not an optimum flow. The charts and images are simple and can be understood by reading them, requiring no additional information. As well, each section focuses on what the header prompts and properly informs the reader on the subject of that section. Overall the organization is lacking, however, the information is easily presented.

    Formating was well done, but the writing requires editing. In the four paragraphs, the word count is kept minimal and paragraph form is used which prevents the poster from becoming busy. However, as I previously stated, the writing needs editing. There are grammatical errors present in all four of the paragraphs and unnecessary phrases added to sentences. This writing is not suitable for scientific purposes.


Poster review pt 1

Submitted by mpetracchi on Mon, 11/04/2019 - 00:17

This poster created by Hamza Nabhan and Amhed Sultan discusses the benefits of nuclear energy and whether or not it should be implemented in Oman. A peer-review of the poster has yet to be conducted so the information presented may have some factual errors. In my breakdown analysis, I’ll be looking at four categories; design, organization, writing, and content.

    At first glance, the poster looks visually appealing, however, there are some clear setbacks as it’s further analyzed. The initial pop of the colors invites the eyes to delve deeper into the content. They aren’t too bright, and when placed over a grey background give the poster a mellow yet inviting look. Besides color, the rest of the poster seems to be lacking in the design component. Next to the pie chart, there’s an awkward spot of white space and there are typography inconsistencies across the entirety of the poster. The same font is used throughout the text boxes however they have different spacing patterns and alignments. Text in section 4 is more left-aligned in the top paragraph than the bottom one. This poster design requires design tweaks to improve the overall presentation.


Minoan Civilization 2

Submitted by mpetracchi on Thu, 10/31/2019 - 21:30

Palaces were large scale structures commissioned by elites who had some control over the people living on Crete. The elites used 3 strategies to get the Minoan masses to accept their rule. First, benefits included being a part of a group with an impressive and immense structure used for rituals and gatherings and fortifications to towns for protection (Minoans of). Second and third, according to archaeologists, previous religious sites were replaced by the palaces or ‘state’ shrines, which implies the elites may have coerced people into abandoning their previous beliefs and pushed people to adopt a new ideology. These state shrines or palaces were large building complexes with multiple floors and specialized rooms. The elites that lived here enjoyed lavish lifestyles; bathrooms with wooden seats and possible flushing apparatuses leading to the main drainage system (First Aegean). In lower rooms, large ceramic jars indicate palaces were storage facilities used for storing, redistributing, and trading wine and olive oil (Minoans of). Evidence also shows the Minoans were in contact with Egypt, exchanging their cloth, timber, and foodstuffs, for copper, tin, gold, silver, and hippopotamus ivory (Minoans of).


Photosynthesis: Light Reactions

Submitted by mpetracchi on Tue, 10/29/2019 - 11:23

Plants require light energy and water to produce energy-rich compounds which can later be used to fuel sugar making mechanisms. In order to first capture light energy, a plant will use chlorophylls a and b in a chloroplast. These kinds of chlorophylls absorb red and blue light, therefore reflect green light waves and appear green to us. The electrons are captured in photosystem 2 and transferred to photosystem 1 and eventually to the NADP reductase where they are used to add a Hydrogen to it and make NADPH. Water is broken down in photosystem 2, removing the hydrogen and producing free hydrogen and a diatomic oxygen molecule. The hydrogen goes into the thylakoid lumen of a chloroplast to create a high gradient that is then used to drive ATP synthase to make ADP into ATP. 

Lotka-Volterra competition model

Submitted by mpetracchi on Tue, 10/29/2019 - 11:00

In any given ecological community where multiple species use the same resource, there is bound to be competition. Competition between two species will always hinder both populations as long as both are present because the maximum capacity of the environment can only hold so many individuals. Studying these sorts of interactions allows scientists to understand how two species interact and how stable their interaction is. In order to quantify the competition of two species, scientists use the Lotka-Volterra equation. This equation takes into account the populations of both species, the effect of one on the other, and the total carrying capacity to produce a value indicating how the target population will grow. A graph can be plotted using the zero growth isoclines for each species; the number of individuals that could be sustained given only 1 species is present. Interpreting the graph will grant the best understanding of how these populations are interacting. If the species populations seem to converge at 1 point in the graph then there is said to be a stable equilibrium. An unstable equilibrium happens when there are 'risk' zones and if the number of individuals falls within these zones it is likely one population will push the other to extinction.

Minoan Civilization

Submitted by mpetracchi on Mon, 10/28/2019 - 23:55

Located on an island in the south Aegean sea, an ancient civilization known as the Minoans ruled for over 600 years. Archaeologists know of this great civilization in part due to Sir Arthur Evans, a very rich man who was determined to discover who these people were. At some point in his life, Evans came across some seal stones which depicted bulls and mythological creatures with origins supposedly on the island of Crete. Not much else was known at the time, and because of that Evans became inspired to pursue his curiosity. Excavations went underway, lead by specialists Evans hired, and quickly they began to uncover the secrets of Crete. Being the eccentric person Evans was, he took it upon himself to reconstruct many of the damaged sites he was exhuming based on his interpretations. On Crete, there were great palaces and villas, many adorned with paintings referred to as frescos depicting life in ancient Minoan society such as the sport of bull-leaping and elite women. Explorations uncovered large ceramic jars at the palace of Knossos estimated to collectively house 62,000 gallons of liquids. Evidence of the types of foods grown here suggests these liquids were olive oil and wine collected as taxes from nearby estates. 


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