Scientific writing 3.0: A reader and writer's guide - Jean-Luc Lebrun, Justin Lebrun 2021

Solution
Set progression tracks for fluid reading
The reading toolkit

· Author’s intention and key points

The author seems to be making two points in this paragraph. Firstly, an explanation of the propagation cycle of the dengue virus (sentences 1, 3, and 4); and secondly, the conditions for rapid disease spread (sentence 2).

· Topic and progression scheme

There are at least two possible topics: the virus (repeated three times) and the mosquito (repeated four times). Either one can be the constant topic in all sentences. Regarding sentence order, since the paragraph (not shown here) that follows our sample paragraph describes what the community can do to stop the propagation of dengue fever, the last sentence must be similar to sentence (2).

· Text restructure taking into account the reader’s prior knowledge and anticipating what the reader may not know

Having monitored how thousands of scientists rewrite this paragraph in our workshops, I would like to warn you about potential time-wasting pitfalls. Some of you may think that reordering the sentences to fix the lack of progression is enough. You clearly see that the second sentence is out-of-place and move sentence 2 to sentence 4.

(1) The transmission of the dengue virus to a human occurs through the bite of an infected female Aedes mosquito. (3) The mosquito becomes infected when it feeds on a blood meal from a human carrier of the virus. (4) The virus multiplies inside the infected mosquito over three to five days and resides within its salivary gland. (2) In addition, the disease spreads rapidly in densely populated areas because of the lack of effective mosquito control methods, the increase in air travel, and poor sanitation in areas with a shortage of water.

However, this creates a disconnection between part 1 of the paragraph (the transmission cycle) and part 2 (spread of the disease). Why? After moving sentence 2 to the end of the paragraph, sentence 4 now becomes sentence 3 which ends with “and resides within its salivary gland.” Moving from the salivary gland of a mosquito to the spread of the disease is a conceptual jump too great for the reader. Therefore, do not describe the cycle using the sequence Mosquito infects Human — Human infects Mosquito, but instead choose the sequence Human infects Mosquito — Mosquito infects Human. That way, the salivary gland sentence will be the second sentence in the paragraph, in the middle of the sequence. In that position, it does not create any problem.

The sentence that ends the paragraph has three problems.

In addition, the disease spreads rapidly in densely populated areas because of the lack of effective mosquito control methods, the increase in air travel, and poor sanitation in areas with a shortage of water.

1. The bogus transition word “in addition” must go. But even when it is removed, the sentence starts with the wrong topic: the disease. Either you write an additional sentence with words extracted from the last sentence to act as glue between the two parts (cycle and spread), or you find in that last sentence old information that can be brought upfront and used as the sentence topic.

2. Examine the information given in that sentence. Is all of it useful? Remember that the next paragraph following the one you rewrite is about community action to stop the spread of the disease.

3. You are probably new to the topic of dengue fever. Yet, you know that mosquitoes need water to breed their larvae. Knowing this, does everything in that sentence make sense? Is there a knowledge gap that needs to be bridged?

Final text (version one — Virus is the constant topic)

The dengue virus from a human carrier enters the female Aedes mosquito via the infected human blood she feeds on. The virus then multiplies inside the mosquito’s salivary gland over three to five days. It is transmitted back into another human through the saliva injected by the infected mosquito when she bites. The virus spreads rapidly in areas where large numbers of humans and mosquitoes cohabit. This spread is accelerated with human travel (air travel particularly), ineffective mosquito control methods, and poor sanitation in areas with water shortages.

Progression is built around a constant topic. The progression is also a time-based progression (the transmission cycle) and a logical progression (amplification: from limited to extended, from specific to general). The fourth sentence acts as a bridge between the two parts. It is built by removing an element from the last sentence of the original version — ’densely populated areas’ — and developing it as a full sentence.

This paragraph is understandable by experts who have lived in tropical countries, but not by “the rest of us”. Some say: I know that mosquitoes breed in water, so if there is a shortage of water, how do mosquitoes reproduce? The lack of knowledge leads to a lack of understanding even though the text is clear.

Final text (version two — Mosquito is the constant topic)

The female Aedes mosquito feeds on the infected blood of a human carrier of the dengue virus. Inside the mosquito salivary gland, the virus multiplies over a period of three to five days. Subsequently, when the infected mosquito bites, its saliva carries the virus back into another human. Ineffective mosquito control methods cause the dengue virus to spread rapidly, particularly in densely populated areas at the end of the rainy season due to the sporadic rains. At that time, mosquitoes enjoy abundant breeding sites such as puddles of stagnant water and large opened vats storing rainwater for the dry season.

In the second version, the mosquito is the constant topic in all sentences. The connection between the end of the transmission cycle and the spread of the disease is established simply by bringing upfront in the rewritten sentence an element — ’ineffective mosquito control’ — that was in the middle of the last sentence in the original version. Some information from the original sentence was removed, and extra details were added to make this paragraph clearer and to prepare the transition to the next paragraph on community action. The disappearance of air travel is intentional since air travel is not directly relevant to the villagers who are part of the community; and so is the removal of ’water shortages’, which is counterintuitive since mosquitos need water to breed. The additional information clarifies the link between the shortage of water and the spread of the disease.

Final text (version three — sequence progression and Cycle topic)

The reproduction of the dengue virus relies on a three-step cycle. First, the virus enters the female Aedes mosquito when the mosquito feeds on the infected blood of a human host. Once inside the mosquito salivary gland, the virus then multiplies over a period of three to five days. The cycle is complete when the virus returns to another human through the saliva injected by the infected mosquito when it bites. This cycle is repeated rapidly (sometimes at epidemic speed) in densely populated areas when people travel, and when mosquito control is ineffective, particularly in areas with water shortages where mosquitoes breed in open air water storage containers.

In this case, the progression is sequential: three steps. The reader is counting. When the sequential progression ends, the constant topic “Cycle” returns at the end of the paragraph.

Final text (version four — greater knowledge gap — children with some prior knowledge on mosquitos)

People sick with Dengue fever carry the dengue virus inside their blood. When that blood is sucked by a female mosquito called Aedes Aegypti — that’s her family name — the blood carries the virus inside of her. It does not harm her, it simply invades her body. Fifteen days after it got in, it arrives inside her saliva and stays there to multiply, and multiply, and multiply for 3 to 5 days. So when the female mosquito bites someone else, her saliva carries a whole army of dengue viruses into the blood, enough to make that person sick. Where many mosquitos and people live together, dengue fever spreads very fast. It spreads even faster when people travel by plane, or when people are careless and let the Aedes Aegypti mosquitos lay thousands of eggs on the side of open water containers like old tires or flower pot plates.

Children require less sophisticated vocabulary. Carrier, infected, densely populated, control method, these are all adult words. They need spoken language, not written language. They need intermediary explanations, examples, numbers, personification, and drama.

One final word of caution: Do not attempt to “fix” progression problems in a paragraph without taking into account the topic of the next paragraph. Progression applies between paragraphs as much as it applies between the sentences of a paragraph. Progression problems are not always fixed by moving sentences around. In many cases, an unclear text needs complete restructuring. To restructure, understand the author’s intention, and identify the key points of the argument presented and their underlying logical connections.

¹ Reprinted excerpt with permission from Wolynes PG. (2001) Landscapes, Funnels, Glasses, and Folding: From Metaphor to Software, Proceedings of the American Philosophical Society 145: 555—563

² ibid.

³ Widjaja E, Li C, Garland M. (2004) Algebraic system identification for a homogeneous catalyzed reaction: application to the rhodium-catalyzed hydroformylation of alkenes using in situ FTIR spectroscopy. Journal of Catalysis 223: 278—289, with permission from Elsevier.

⁴ Reprinted excerpt with permission from Wolynes PG. (2001) Landscapes, Funnels, Glasses, and Folding: From Metaphor to Software, Proceedings of the American Philosophical Society 145: 555—563