GE 7 Finals

• Biodiversity is the term used to refer to the variety of living organisms on earth
• Biodiversity provides fresh air, safe drinking water, and food
• Biodiversity and the environment are so intricately linked, interacting, and interconnected which means that they both affect each other in ways that are direct and indirect
• A changing environment has tremendous impacts on biodiversity and vice versa
• Humans rely heavily on the environment, specifically on the resources and services that it provides
• Environmental changes and biodiversity loss can lead to the emergence of infectious diseases
• Biodiversity


  The variability of all living organisms that live in land and water
• Different views on biodiversity

  • Biologists: The diversity of all living beings
  • Farmers: Potential resources derived from soils, territories, and regions
  • Industry: Reservoir of genes useful in biotechnology; Set of exploitable biological resources (timber, fish, etc.)
  • General public: The landscapes and charismatic species threatened by extinction
• Niche


  The set of ecological conditions under which a species can exploit a source of energy effectively enough to be able to reproduce and colonize further such sets of conditions
• Niche


  The role that the organism plays in the ecosystem: 'the habitat is the ''address'' so to speak, and the niche is the ''profession'
• Biodiversity ensures health and food security, helps fight disease, benefits business, provides livelihoods, and protects us
• There is a clear link between biodiversity, climate, and global health pandemics
• Biodiversity loss and ecosystem collapse is one of the top five risks in the World Economic Forum's 2020 Global Risks Report
• Biodiversity loss undermines the achievement of most of the UN sustainable development goals
• Biodiversity loss leads to only a few species and these species will carry the diseases that are transmissible to humans
• Environmental changes that contribute to the spread of diseases

  • Agricultural intensification
  • Increased temperature
  • Deforestation and habitat encroachment
  • Dams, canals, irrigation
• Zoonosis refer to diseases that come from animals and that can be passed to humans
• The emergence and outbreak of diseases which and affect human populations have been linked to changes in the environment
• Electron Microscopy (EM)


  A tool that enables biologists to capture photos of their samples at a greater and better resolution, than with a light microscope. Also used for obtaining high-resolution images of non-biological specimens.
• Electron Microscope


  • Utilizes a beam of electrons to illuminate a specimen and produce high precision and a magnified image
  • Produces greater and better resolution photos than conventional microscopes
• Types of Electron Microscopy

  • Scanning Electron Microscopy (SEM)
  • Transmission Electron Microscopy (TEM)
• Scanning Electron Microscopy (SEM)

  1. Electrons are backscattered due to surface interactions

  2. Interactions produce secondary electrons which are also backscattered

  3. Both types of electrons are detected and used to build an image
• Transmission Electron Microscopy (TEM)


  1. Electrons don't scatter, rather they pass through the material and are detected

  2. Some electrons are scattered and can be analyzed using reflection electron microscopy (REM)
• EM methods can clearly image (with a high resolution), analyze and provide a lot of information of all types of nanomaterials, nanostructures and nanoscale surfaces
• Optical microscopes can be adapted to observe the nanoscale, but this is currently a less popular option with the other microscope technologies available nowadays
• Nanosized particles


  Exhibit different properties than larger particles of the same substance
• Study of phenomena at the nanoscale


  • Leads to learning more about the nature of matter
  • Develop new theories
  • Discover new questions and answers in many areas, including health care, energy, and technology
  • Figure out how to make new products and technologies that can improve people's lives
• Property


  • Describes how a material acts under certain conditions
  • Usually measured by looking at large (~10^23) aggregations of atoms or molecules
• Types of Properties


  • Optical Property
  • Electrical Property
  • Physical Property
  • Chemical Property
• Optical Property - Gold


  • Bulk gold appears yellow in color but nanosized gold appears red in color
  • The particles are so small that electrons are not free to move about as in bulk gold, so they react differently with light
• Optical Property - Zinc Oxide (ZnO)

  • Large ZnO particles can block UV light and scatter visible light, appearing white
  • Nanosized ZnO particles can also block UV light, but are so small compared to the wavelength of visible light that they don't scatter it and appear clear
• Electrical Property - Nanotubes


  • Nanotubes are long, thin cylinders of carbon
  • They are 100 times stronger than steel, very flexible, and have unique electrical properties that change with diameter, "twist", and number of walls
  • They can be either conducting or semi-conducting
• Melting Point (Microscopic Definition)


  • The temperature at which the atoms, ions, or molecules in a substance have enough energy to overcome the intermolecular forces that hold them in a "fixed" position in a solid
  • Surface atoms require less energy to move because they are in contact with fewer atoms of the substance
• At the nanoscale, the melting point is lower for smaller particles
• Why do properties change at the nanoscale?

  • Dominance of electromagnetic forces (gravity becomes negligible)
  • Importance of quantum mechanical models (instead of classical mechanics)
  • Higher surface area to volume ratio (more atoms on the surface)
  • Random (Brownian) motion becomes more important
• Richard Feynman


  • American theoretical physicist widely regarded as the most brilliant, influential, and iconoclastic figure in his field in the post-World War II era
  • Made key contributions to quantum electrodynamics, Feynman diagrams, superfluidity, weak force theory, and parton theory
• Eric Drexler


  • American engineer best known for seminal studies of the potential of molecular nanotechnology (MNT)
  • Wrote the book "Nanosystems: Molecular Machinery, Manufacturing, and Computation" which received an award
  • Current research explores prospects for advanced AI technologies
• Gerd Binnig


  • German-born physicist who shared the 1986 Nobel Prize in Physics with Heinrich Rohrer for their invention of the scanning tunneling microscope (STM)
  • The STM produces images of surfaces in such fine detail that individual atoms can be clearly identified
• Heinrich Rohrer


  • Swiss physicist who co-invented the scanning tunneling microscope (STM) with Gerd Binnig
  • The achievement garnered them half of the 1986 Nobel Prize in Physics, with the other half going to Ernst Ruska for the invention of the electron microscope
• Nanoscience


  The study, manipulation and engineering of matter, particles and structures on the nanometer scale