Ecologies Final

What are the 8 risk factors for asthma

Family history, viral respiratory infections, allergies, occupational exposures, smoking, air pollution, obesity


Family history

• If you have a parent with asthma, you are three to six times more likely to develop asthma than someone who does not have a parent with asthma.

Viral respiratory infections

• Respiratory problems during infancy and childhood can cause wheezing. Some children who experience viral respiratory infections go on to develop chronic asthma.

Allergies

• Having an allergic condition, such as atopic dermatitis (eczema) or allergic rhinitis (hay fever), is a risk factor for developing asthma.

Occupational exposures

• If you have asthma, exposures to certain elements in the workplace can cause asthma symptoms. And, for some people, exposure to certain dusts (industrial or wood dusts), chemical fumes and vapors, and molds can cause asthma to develop for the very first time.

Smoking

• Cigarette smoke irritates the airways. Smokers have a high risk of asthma. Those whose mothers smoked during pregnancy or who were exposed to secondhand smoke are also more likely to have asthma.

Air Pollution

• Exposure to the main component of smog (ozone) raises the risk for asthma. Those who grew up or live in urban areas have a higher risk for asthma.

Obesity

• Children and adults who are overweight or obese are at a greater risk of asthma. Although the reasons are unclear, some experts point to low-grade inflammation in the body that occurs with extra weight. Obese patients often use more medications, suffer worse symptoms and are less able to control their asthma than patients in a healthy weight range.

What is the old friends/hygiene hypothesis?

The decreasing incidence of infections in western countries and more recently in developing countries is at the origin of the increasing incidence of both autoimmune and allergic diseases.

What spurred the birth of the environmental justice movement?

Protests over hazardous waste sites in three southeastern states that were disproportionately located near Black communities

What are the areas of the brain impacted by depression?

Thalamus, hypothalamus, amygdala, ACC, prefrontal cortex

• Thalamus – Increased activity – arousal and awareness, sleep and hygiene. Stimulates the Amygdala

• Hypothalamus – neurotransmitters responsible for mood and emotional expression. Serotonin pathways regulate mood and appetite. Norepinephrine pathways regulate emotions and energy level.

• Amygdala: Regulate feelings (higher). Hippocampus releases cortisol enlarging this part of the brain

• Anterior cingulate cortex – Emotional response to pain and regulation of anger (higher)

• Prefrontal cortex – complex thinking, personality, social behavior (Norepinephrine and serotonin affect this) Attention, concentration, memory information processing (decreased activity).

Main physiological properties and hormones of the HPG axis?

HPG axis: The hypothalamus and the pituitary gland produce hormones that control the reproductive organs (gonads). 

• Hypothalamus: Gonadotropin Releasing Hormone (GnRH) – peptide hormone

• Pituitary gland: glycoprotein hormones

  • Follicle Stimulating Hormone (FSH)

  • Luteinizing Hormone (LH)

• Gonads (ovaries & testes): steroid hormones

  • Produces gametes (egg and sperm cells)

  • Produces major sex hormones (steroids)

  • Testosterone – major role in males

  • Estradiol and progesterone – major roles in females

What is the Barker hypothesis?

Links conditions in the intrauterine environment to the later development of adult chronic disease

Sensitive periods for brain synapse formation:

• Language peaks at 9 months 

• Higher cognitive function peaks at 1 year 

• Sensing pathways (vision/hearing) peaks at 3 months 

How do we evaluate reproductive health using our frameworks? (Epigenetics, across the life course, evolutionary biology, in regard to one health, etc)

Adaptation, maladaptation, etc.

Adaptation – suppressing reproduction temporarily to allow for energy expenditures necessary to accommodate other essential activities

• Common throughout history

• Common in both developing and “developed” societies

Maladaptation – negatively impacting reproduction, sometimes permanently, in response to stressors/exposures

• Common in modern society

Many types of reproductive suppression, not as pathology, but as adaptation resulting from natural selection during human evolution.  

• Assumption – during times of temporary adversity when offspring are less likely to survive, those who temporarily suppress reproduction in response to environmental cues may have selective advantage.

Describe the 3 frameworks

One Health

• The triad of human, animal and ecosystem health are inextricably linked

• The ill health of one affects the health of the others

• The determinants and contributing factors affecting a health issue in one area very often apply to the other two as well

Life Course Theory

• Looks back across the lifespan/generations for clues to current pattern of health and disease, recognizing that both past and present experiences are shaped by the wider social, economic and cultural context

• T2E2: Timing, Timeline, Environment, Equity

Evolutionary Biology

• Natural selection promotes fitness to reproduce, not for health/longevity

• Evolutionary history does not cause disease, it impacts our risk of developing disease in particular environments

• We are now living in novel environments compared to where we evolved

What are harmful agricultural practices and their effects?

Monocropping, tillage-based farming, chemical fertilizers and pesticides

Monocropping 

• Many industrial farms grow one single crop, year after year after year. 

• Depletes the soil of nutrients and contributes to soil carbon loss and soil erosion

• Monocropping can threaten food security. With a single species of crop on millions of acres, one disease could potentially wipe out an entire food system.

Tillage-based farming

• Tilling reduces microbe populations in the soil, promotes soil erosion, and releases greenhouse gases. 

• Today, 93% of the world’s cropland uses tilling-based methods for production.

Chemical fertilizers and pesticides 

• ​​Herbicides, pesticides, and fungicides can help increase crop yield by keeping weeds and harmful organisms under control.

• Pesticides that kill bugs and disease-causing microbes can also destroy the instrumental microbial populations in the soil.

• Pesticides can also disrupt pollinator life cycle

What are the effects of urbanization on plant and human health? + the heat island effect

• Human health 

  • Industrialization, blurred lines between rural and urban, plants and concrete 

  • Medicinal plant knowledge and food/nutrition knowledge 

  • Habitat destruction increases contact between wildlife and humans, and intensive farming and exotic animal trade amplify disease spillover risk.

• Plant health 

  • Spring-blooming plants in a variety of ecosystems in North America, Europe, and China tend to bloom earlier in the city than in the surrounding un-urbanized habitat.

  • Researchers attribute advanced flowering in urban environments to the Heat Island Effect.

    • Phenomenon where urban areas experience higher temperatures than surrounding rural or suburban areas, primarily due to the increase concentration of heat absorbing surfaces (buildings, roads, paved areas made of asphalt and concrete), reduced vegetation, human activities (driving, industrial processes, air conditioner) 

What is bioremediation?

The use of living organisms, especially microbes, to clean up contaminated environments

• Soil microbes can naturally detoxify environments polluted by pesticides

Describe the basics of the two immune systems

Innate Immune System: Rapid response, no memory, not specific to a particular antigen, constant during a response, send chemical messages to the adaptive immune system

Adaptive/acquired immune system: Slower response, long lived memory, specific to particular antigen

• Cell mediated - T-lymphocyte: Killer cells & Helper cells

• Humoral - B-lymphocytes (IgG, etc.)

What are allergies?

Excessive and undesired reaction by the body to an allergen/antigen, ex: pollen/dust, animal hair/saliva/scales, food additives, etc.

What are the types of allergic reactions?

• Type I

  • Anaphylactic / Immediate 

• Type II

  • Cytotoxic

• Type III

  • Immune complex 

• Type IV

  • Cellular

• IgE responsible for 90% of response

  • Triggers mast cells to release histamine 

  • Histamine’s effects

    • Nose/eyes/mouth increase mucus production 

    • Airway smooth muscle contraction (shortness of breath)

  • Skin inflammation – hives/redness, itchiness

What are the main greenhouse gas emissions?

• Carbon Dioxide 

  • 65% of global CO2 emissions are caused by fossil fuels and industrial processes

  • 11% of global CO2 emission are caused by forestry and other land use 

• Methane

  • 16% of global emissions 

• Nitrous oxide 

  • 6% of global emissions

What are the imapcts of climate change? On biodiversity, emerging diseases, and micro/macro events?

• Impact on Biodiversity

  • Decreased plant and soil organism’ species diversity

  • Loss of nutrients and soil structure, reduced soil conservation, and soil erosion 

    • Reduces primary production and nutrient cycling → desertification 

• Impact on Emerging Diseases

  • Pathogen/host/vector dynamic changes 

• Micro events

  • The Metabolic Theory of Ecology - Predicts how metabolic rate, by setting the rates of resource uptake from the environment and resource allocation to survival, growth, and reproduction, controls ecological processes at all levels of organization from individuals to the biosphere

• Macro events 

  • Periodic plant and animal life cycle events 

  • Migration pattern changes 

  • Loss of biodiversity