令和 4 年度
Ａ Ｏ 入 試 問 題 集（歯学部）公表期限：2025 年 3 月末
東北大学入試センター※ 以下の(1),(2)の場合を除き，複製，転載，転用することを禁じます。
(1)受験予定者が自主学習のために使用する場合(2)学校その他の教育機関(営利目的で設置されているものを除く。)の教職員が教育の一環として使用する場合（Excerpts from THE GOLDEN BOOK ON WRITING by David Lambuth, et al., copyright ©1963 byS. Heagan Bayles; Copyright © 1964, renewed 1992 by The Viking Press, Inc. on Introduction.
Used by permission of Viking Books, an imprint of Penguin Publishing Group, a division ofPenguin Random House LLC. All rights reserved.より一部改変）

world, the requirement of nutrients will be 28.8 million tons while the availability will be only
21.6 million tons, creating a shortage of about 7.2 million tones of required nutrients. To feed
the growing population with the deficit amount of available nutrients, the world certainly needs
to flourish agricultural productivity and that too indeed in a sustainable and ecofriendly way.
Considering the hazardous effects of chemical fertilizers, biofertilizers are supposed to be a safe
alternative to chemical inputs and minimizes ecological disturbance to a great extent.
Biofertilizers are cost-effective, ecofriendly in nature, and their prolonged use enhances soil
fertility substantially. It was reported that the use of biofertilizers elevate crop yield around 1040 % by increasing contents of proteins, essential amino acids, vitamins, and nitrogen fixation.
The benefits of using biofertilizers includes cheap source of nutrients, excellent suppliers of
micro chemicals and micronutrients, suppliers of organic matter, secretion of growth hormones,
and counteracting negative impact of chemical fertilizers. Different microbes are vital
components of soil and they play a crucial role in various biotic activities of the soil ecosystem
which make the soil dynamic for nutrient mobilization and sustainable for crop production.
(4) Plant growth-promoting bacteria includes those bacteria that are free-living, andform specific symbiotic relationship with plants, bacterial endophytes that can colonize atsome portions of plant tissue, and *Cyanobacteria. Although all the bacteria are distinct fromeach other in various ways, they all exhibit the same mechanisms while promoting bacterialgrowth. They may promote growth directly by either facilitating resource acquisition ormodifying plant hormone levels and indirectly by reducing the inhibitory effects of various
pathogenic agents on plant growth and development.
（Adapted from "Biofertilizers: a potential approach for sustainable agriculture
development" by Trishna Mahanty et al; Springer Nature. Copyright © 2016,Springer Nature.より一部改変）*indiscriminate : 無差別*eutrophication : 富栄養化
*phosphates: リン酸塩
*rhizosphere : 根圏（植物の根の分泌物と土壌微生物とによって影響されている土壌空間である）*Cyanobacteria: ラン藻類

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[ III ]Our findings show how complex the relationship between maintaining a healthy

weight and brain health is. While our study doesn't show obesity or excess weight to be a directcause of Alzheimer's disease, the findings do suggest that being overweight or obese throughout
a person's lifetime lowers the brain's *resilience to the damaging effects of the disease. This
results in more severe symptoms and faster decline in those who develop Alzheimer's.
Our study also highlights the importance of looking after our weight from an early
age to avoid the negative effects of excess weight on the brain. This is especially important after
middle age, where the risk of developing Alzheimer's disease increases considerably - andbecause damage to the brain is usually not reversible and accumulates over time.
Although the cause of Alzheimer's disease is not known, we know that a number offactors can increase our risk of developing it - excess weight being one of them. Obesity puts
a severe strain on the * cardiovascular system and damages the brain *vessels' walls.
This in tum results in high levels of *inflammation, *toxicity to brain cells, and lower
metabolism and blood flow in the brain. Our study adds to the large body of evidence thatindicates the damaging effects of obesity on the *vascular system worsen some of themechanisms that cause Alzheimer's disease.
There's still no cure for Alzheimer's disease, which is why it's important to take as
many precautions as possible from an early age to prevent the likelihood of developing it.

（Adapted from "Alzheimer’s disease: obesity may worsen its effects – new research" by Matteo De（出典： "Alzheimer's disea se: obesity may worsen its effects - new resea rch" February 1,Marco, The Conversation, February 1, 2021. Copyright©2021, The Conversationより一部改変）

2021, THE CONVERSATION より一部改変）*exacerbate: 悪化させる*cognitive impairment: 認知機能障害*dementia: 認知症*body mass index: ボディマス指標 (BMI: 体重と身長から算出される肥満度を表す体格指数）*waist circumference: 腹囲- 11 -