Category: biology

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Through the Fantastic Eyes of Frogs and Toads: How Scientists Study what Frogs and Toads See

with Rayna Bell Ph.D., Assistant Curator of Herpetology, California Academy of Sciences

NEW DATE! Wednesday, November 15th, 2023 – TLHS Innovation Hub – 7:30 – 8:30pm

Green tree frog. Photo by Andrew Stanbridge
A Hyperolius molleri frog on São Tomé Island. Photo by Andrew Stanbridge

Dr. Rayna Bell grew up in Marin County and her love of science was nurtured by several wonderful teachers at Drake (now Archie Williams) High School. Rayna attended College of Marin and the University of California, Berkeley where she studied biology and interned at U.C. Berkeley’s Museum of Vertebrate Zoology where she started doing research on Australian frogs and lizards. She received her Ph.D. in Ecology and Evolutionary Biology from Cornell University, during which she conducted research on African tree frogs, and joined the Smithsonian Institution’s National Museum of Natural History as Curator of Amphibians and Reptiles. In 2019, Rayna moved back home to the California Academy of Sciences where she is the Associate Curator of Herpetology. Rayna’s research focuses on the ecology, evolution, and conservation of amphibians and reptiles with an emphasis on island biogeography, hybrid zones, and coloration.

Links:

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We Need New Antibiotics – Why Do We Have So Few?

with Julia Schaletzky Ph.D. of the Center for Emerging and Neglected Diseases and the Drug Discovery Center at UC Berkeley

Wednesday, November 1, 2023, Terra Linda High School Innovation Hub

Center for Emerging and Neglected Diseases
Center for Emerging and Neglected Diseases

Description: Antibiotics are one of the triumphs of science and we have become used to them as “silver bullets”, fighting potentially life-threatening infections. As drug-resistant pathogens continue to emerge, what are our options? Why are so few new antibiotics being developed and how do we have to think about the market-driven model of drug development in this context? Dr. Schaletzky will provide an overview about chemistry, discovery/development, overuse and the economics of antibiotic development, and discuss potential solutions to a problem that should be on everyone’s mind.

Bio.: Dr. Julia Schaletzky is the Executive Director of the Center for Emerging and Neglected Diseases and the Drug Discovery Center at UC Berkeley. After studying biochemistry in her native Germany, she moved to Harvard Medical School for graduate school. Interested in applied science, Dr. Schaletzky joined a biotechnology company, Cytokinetics, to develop new therapies for heart disease and neurodegenerative disorders, with several molecules in late-stage clinical trials. In her role at UC Berkeley, she focuses on interdisciplinary approaches and public/private partnership for the discovery and development of new therapies and tools, particularly for unmet medical needs. Dr. Schaletzky is also is a lecturer at the Haas School of Business, teaching Bioentrepreneurship, Access to Medicines and Drug Development for Neglected Diseases. She has received NIH-funded grants to support underrepresented minorities and women in STEM in the U.S. and runs a program in Uganda to build local research capacity. Dr. Schaletzky is broadly interested in global public health, bioethics, and the governance of processes that end up influencing who gets care and who does not.

Julia Schaletzky Ph.D. of the Center for Emerging and Neglected Diseases and the Drug Discovery Center at UC Berkeley
Julia Schaletzky

Links

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Blinded by the Lack of Light

Meredith Protas and student

Genetics of Pigmentation and Eye Loss in the Cave-dwelling Crustacean, Asellus aquaticus

with Meredith Protas, Ph.D. of Dominican University of California, San Rafael

Join us for a Zoom session with Dominican University’s Dr. Meredith Protas. Dr. Protas’s lab investigates the genetics and evolution of cave dwelling animals, specifically crustaceans. The isopod crustacean, Asellus aquaticus, has two different forms: a cave dwelling form and a surface dwelling form. Interestingly, these two forms can be mated together which ultimately allows for an understanding of the genetics behind characteristics found in the cave form such as eye and pigment loss. The questions the lab are asking include:

  • What are the genes and mutations responsible for cave-specific characteristics like eye loss, pigment loss and increased appendage length?
  • In different cave populations are the same or different genes responsible?
  • Where does the variation that causes cave-specific characteristics come from?

To register for this event ask your teacher to contact us, or send a request for registration information via our contact form.

Meredith Protas PhD
Meredith Protas PhD

Before joining the Dominican faculty, Dr. Protas did research at UC Berkeley on cave-dwelling crustaceans and studied the genetic basis of human eye disease in her research work at UCSF. Currently, she uses genetic, molecular, and developmental techniques to answer evolutionary questions about cave animals. Dr. Protas holds a BA in Biology from Pomona College and a PhD in Genetics from Harvard University.

Links:

Photo of Asellus aquaticus, a crustacean
Asellus aquaticus, a crustacean

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“When Parasites Kill” – An Interview With Stephanie Rasmussen, M.S.

By Rachael Metzger, Marin Science Seminar Intern 


Stephanie Rasmussenholds a Bachelor’s degree in Biochemistry and a Master’s degree in Biology from Dominican University of California and is coming to Marin Science Seminar Wednesday, October 18th, 2017 to speak about her research on malaria in Uganda.
Stephanie Rasmussen first became interested in biology as a high school student, but it was not until her freshman year of college that she learned what research was and thus realized her passion. Research sparked her fascination with lab work, which allowed her to test biological theories in a lab. Rasmussen decided to study biochemistry because she wanted to “have a deeper understanding of why different reactions happen inside cells to make them work correctly,” as well as to “help scientists, doctors, and other health professionals understand how and why different diseases make people sick.”
As a sophomore in college, Rasmussen worked in her graduate student advisor’s malaria lab. She volunteered in the lab all through her undergraduate years and continued to work in the lab after she graduated to get her Master’s degree in biology. Rasmussen’s passion is in studying human diseases; working in the malaria lab helped further her interest. Graduate school was when she started studying malaria parasites on location in Uganda. Rasmussen shares how this excited her, “I got to travel to a malaria endemic region, where I worked on parasites coming directly from malaria patients.”

Mosquitoes carry malaria (Source: scientistsagainstmalaria.net)
Today, Rasmussen’s lab works with people both in the USA and in Uganda. On the importance of teamwork she says, “I love all of my coworkers. Success in science is all about teamwork and collaboration.” She enjoys working with a diverse group of people that share similar interests and have a shared goal: reducing the malaria burden. She encourages anyone interested in pursuing biomedical research to make connections with those in the field, and to learn about the work they are doing. She emphasizes the importance of taking advantage of research opportunities in college, “The only way people can find out if they like it is to try it.”


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Stephanie Rasmussen is happy to answer any questions about research as a career at: Stephanie.rasmussen16@gmail.com
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An Interview With Diara Spain, Ph.D

By Rachael Metzger, MSS Intern

 Ocean acidification is an issue becoming apparent in the effects on both sea creatures and humans. Diara Spain, the Associate Professor of Biology at Dominican University, came to Marin Science Seminar to talk to us about her studies in marine invertebrates and the damage ocean acidification is causing them. 

 To learn more about Diara Spain and what inspired her studies we conducted an interview:


 1. How did you get interested in biology? Is there a time, event, 
or person in your life that inspired you to pursue the study?

I’ve always been interested in biology, really science in general. I grew up in rural North Carolina and as a kid it was expected that you’d spend most of your free time outside playing with your friends and pets.  One thing that sparked my interest in marine organisms were the summer vacations at the undeveloped beaches in North Carolina. 
2. Why did you specifically decide to focus on functional morphology, locomotion in echinoderms, and the mechanical properties of crustacean exoskeletons? How do studying these subjects help expand your view on the ocean and how humans are affecting it? 
The essence of functional morphology is “function from form”, this gives us insight into how biological structures can actually work mechanically or physiologically. I find this compelling, especially when you consider marine invertebrates which have a wide array of morphological features. At first glance locomotion in sea cucumbers and properties of crustacean exoskeletons may seem to have little in common, but both topics are based on skeletal support systems which is my major interest. I’ve learned quite a bit about different marine habitats as well as how populations size and  species diversity has changed from my studies.
3. What is the most interesting study you have done to date?
I’d have to say my work on locomotion in echinoderms, specifically sea cucumbers. These are very unusual organisms and the average person may not know much about them, but when I describe them it never fails to amaze. My students enjoy watching the time-lapse videos, I actually gave a talk at the seminar several years ago titled “Life in the Slow Lane”. My studies on crustaceans are just beginning but I fully expect some interesting stories in the future.

4. How do you hope the ocean will look in 20 years and what are some steps we can take to get there?
The oceans are important for the functioning of our global ecosystem as well as the global economy. I’d like to see a habitat that is healthier for animals (including humans)  to live, play and work. 
An example of a smaller step is decreasing the widespread use of disposable plastics while increasing the usage of recyclable/reusable materials. A much larger step is the approval of ocean friendly policies that support conservation and sustainability while restricting damage and pollutants. 
5. What is your advice to teens and young adults who want to help preserve our oceans and the creatures that live in it? 
The best advice is to become involved, this can be done at multiple levels from local and regional up to globally in a way you feel most comfortable. Every fall there is a International Coastal Cleanup Day, San Rafael’s Volunteer Program coordinates people with specific sites locally. Volunteers and donations are also welcome at marine conservation organizations, some focus on a specific animal like sea turtles or dolphins while others focus on a issue such as ocean pollution or habitat restoration. 

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Ocean Acidification: How the Ocean is Acidifying and Affecting the Organisms That Call it Home

By Zack Griggy, San Marin HS

             Pollution is a global problem. One way to find proof of this is to look to the seas. We all know that the oceans have suffered greatly from pollution, evidence of which can be seen almost anywhere, from areas suffering from oil spills to the huge cluster of garbage floating in the North Pacific Ocean. We also know that many aquatic species are dying and going extinct because of ocean pollution. However, oils spills and trash aren’t the only causes. Another cause is ocean acidification, which is caused by air pollution.
             Ocean acidification begins with carbon dioxide. Carbon dioxide is an essential part of photosynthesis in plants. However, it is also a greenhouse gas, and carbon dioxide emissions have become a global problem. Carbon Dioxide is one of the main contributors to both global climate change and ocean acidification. Carbon dioxide is emitted in huge quantities around the world. Part of these emissions are absorbed by the oceans. This leads to chemical reactions within the oceans to form Carbonic Acid from carbonate and hydrogen ions, which are formed using CO2 absorbed by the oceans. Carbonic Acid is the main cause of ocean acidification. For the past 300 million years, the oceans have had a pH of 8.2, but recently since the industrial revolution, that pH has dropped to 8.1. Estimates say that the ocean acidity may drop by another 0.5 pH
            The effects of ocean acidification can be very harmful to marine ecosystems. Many marine organisms such as arthropods, coral, and plankton will be impacted by ocean acidification. These organisms use the process of calcification to create shells, exoskeletons, etc. Calcification relied on using two ions, carbonate and calcium ions. However, Carbonic Acid also uses carbonate ions, which makes it more difficult for the aforementioned organisms to make their exoskeletons or shells. In addition, when more carbon is absorbed by the oceans, hydrogen ions become more abundant, which makes it increasingly more difficult for the organisms to make their exoskeletons.

Sources:
1. https://www3.epa.gov/climatechange/science/indicators/oceans/acidity.html
2. http://www.iiasa.ac.at/web/home/about/news/150203-Ocean-Acid.html
3. http://www.co2science.org/subject/c/summaries/calcification.php
4. http://www.pmel.noaa.gov/co2/story/Ocean+Acidification
5. http://hilo.hawaii.edu/academics/hohonu/documents/Vol09x06OceanAcidification.pdf

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Angiosperms: How the Disappearance of Bees Put Flowers At Risk


By Zack Griggy, San Marin HS

          Plants are unique organisms. They have unique cell structures, ways of making energy, and reproduction. There are many different kinds of plants, but a category of plants called angiosperms makes up 80% of plants. But some of these angiosperms are at risk, as bees and other pollinators, which are vital to angiosperm reproduction, are disappearing.
         Plant reproduction varies among different kinds of plants in two significant ways. The two distinguishing factors that divide the kingdom Plantae are seeding and flowering. Angiosperms are the only group of plants that makes both flowers and seeds.

The various parts of a flower.

         Flowers are the reproductive system of an angiosperm. In a flower, two structures in particular play a vital role in plant reproduction. These parts are the pistil and stamen of a flower. The pistil consists of the ovary, the style and the stigma. The ovary is a small are in the bulb of the flower where eggs are stored. Atop the ovary is the style, a narrow region of the pistil that elevates the stigma. The stigma is the tip of the pistil that catches pollen and directs it down a tube so it can fertilize an ovule. The stamen consists of anthers and filaments. The anther rests atop a filament, which is a long narrow structure that supports the anther, and produces pollen, which can fertilize ovules in the ovary. The plant uses pollination to move pollen from the stamen to the pistil. However, the anther is not capable of pollinating on its own, as the pistil and anther are separated by a small distance. Something needs to pollenate the flower, whether it be wind or a pollinating insect, for the plant to be able to reproduce.
          Bees are unbelievably important pollinators. According to the Michigan State University, bees play a huge role in the environment by maintaining many plant communities. Many of these pant communities are farmed for food. Most fruits and nuts, along with cotton and alfalfa are maintained by bee populations. We need bees for our food and as our population grows, so will our need for bees. 
          Unfortunately, the bee population has been declining over the past 50 years. The decline of the bee population is due to many causes, including pesticides, colony collapse disorder (in which worker bees leave their queen and a few young and nursing bees), predators, and carnivorous plants. These causes are serious threats to the bee population and therefore a serious threat to us.
          Angiosperms are flowering plants that make up 80% of the plant population. They are at risk because bees, their primary source for pollination are disappearing. This can lead to agricultural problems for humans when bees cannot pollinate all of our crops.

Sources:
http://nativeplants.msu.edu/about/pollination
http://www2.epa.gov/pollinator-protection/colony-collapse-disorder
http://time.com/3821467/bees-honeybees-environment/

To learn more about the disappearance of bees, attend Dr. Amber Sciligo’s research presentation on Wednesday, October 21st at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30. 

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Carnivorous Plants

by Jane Casto, Terra Linda High School Freshman

Carnivorous plants is a term often associated with flies and Venus fly traps. There is much more however, to learn about these organisms, and about their complex functions that allow optimal survival and ideal food supply. Scientists have been unraveling the true genius of these plants for years, and even now, breakthroughs are being made in research. To begin, we answer the question: what is a carnivorous plant? 
Carnivorous plants, or insectivorous plants, are plants that have adapted to consuming and digesting insects and other animals. These plants work in a variety of ways based on their species, of which there are 600 known to man. The basic understanding of the makeup of carnivorous plants is uniform throughout the different species. Carnivorous plants have adapted to a low-nutrient environment, making digestion of invertebrates optimal, as it is a low-nutrient energy method of consumption.
the Venus fly trap’s deadly leaves, the vibrant trap ready for action

In the example of a Venus fly trap, this ability to digest small insects and organisms is remarkably dependent on the transfer of electrical signaling. According to ScienceLine, “Each trap is actually a modified leaf: a hinged midriB . . which joins two lobes and secretes a sweet sap to attract insects.” This modified leaf is constant throughout all carnivorous plants, while the sap it produces varies in color, sweetness, and other qualities. Following the example of a Venus fly trap, the sap can attract virtually any small creature, and thus, the Venus fly trap often digests small frogs along with the usual fly. When the actual trap of the Venus fly trap is open, the red belly is exposed for all invertebrates to see. Once the prey has been attracted to the trap, the lips of the trap, or the lobes, close within one tenth of a second! So how does a plant move so quickly?
The answer is within the lobes of the Venus fly trap, where three or more small hairs lie. These hairs act as sensors, and if something brushes against two of these hairs, or brushes against one hair twice, the lobes of the plant will snap shut within 30 seconds of initial contact.
small hairs on specialized leaf, or lobe, of the Venus fly trap.
The science behind the closing of the trap is in the pressure caused by something brushing against the hair. This mechanical energy is translated into electrical energy, causing a small electrical signal. This electrical signal is enough to open pores within the center of the lobe, which allow water flow between the cells on the surface of the lobe. Thus water is transferred from the inner layers of the cells to the outer layer of the cells. During the transfer of water, the pressure within the lobes is drastically changed, causing the lobes to invert. This is how the effect of the Venus fly trap is achieved. 
These beautiful and deadly plants have a unique way of maintaining survival, and in turn are incredibly interesting to learn about and study. 
More on carnivorous plants and when
insects fall victim to them
during the October 21st seminar,
7:30 – 8:30 P.M.
Terra Linda High School, Room 207
320 Albion Way, San Rafael, CA 94903
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Bacteria, Botulism, and Beauty

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By Talya Klinger, MSS Intern

The molecular structure of botulinum toxin
What do foodborne illnesses, neck dystonia treatments, and celebrities’ beauty regimens have in common? Clostridium botulinum, baratii, and other species of Clostridium bacteria produce all of the above and more. These seemingly innocuous, rod-shaped bacteria, commonly found in soil and in the intestinal tracts of fish and mammals, produce one of the most deadly biological substances: botulinum toxin, a neurotoxin that intercepts neurotransmitters and paralyzes muscles in the disease known as botulism. Nonetheless, botulinum toxin isn’t all bad: this chemical not only protects the bacteria from intense heat and high acidity, but it makes for an effective treatment for medical conditions as wide-ranging as muscle spasms, chronic migraines, and, yes, wrinkles. 


C. botulinum
Clostridium botulinum and similar bacteria can make their way into the human body in a number of ways. Wounds infected with Clostridium botulinum or spores ingested by infants can lead to the rare but serious disease of botulism, as can accidental overdoses of medicinal or cosmetic botulinum toxin. Botulism is often foodborne, usually contracted by infants from honey or by adults from improperly home-canned foods and unrefrigerated herb-infused oils. Regardless of where any case of botulism comes from, it causes muscle paralysis, which can manifest as blurred vision, dry mouth, and muscle weakness in adults or lethargy and constipation in infants. These are only early warning signs for an illness that, if left untreated, can paralyze a patient’s respiratory muscles to the point of asphyxiation. Although 95-97% of botulism patients receive treatment and survive, they often require months of intensive care and suffer years of muscle weakness, fatigue, and shortness of breath.

So how does the neurotoxin that makes botulism so deadly work? Clostridium bacteria produce several protein compounds with similar structures and molecular weights, consisting of two chains of amino acids—one small and one large. These two amino acid chains are linked together by a covalent bond between two sulfur atoms, one in each chain. The botulinum toxin proteins bind to nerve endings where they join muscles, blocking the neurotransmitter acetylcholine, which ordinarily causes muscle contractions. This blockage is permanent, paralyzing the muscle until a new nerve ending forms a synaptic connection with it. Because the process of forming new neuromuscular junctions takes at least 2 or 3 months, the affected muscle will often atrophy in the meantime, causing the long-term side effects that plague botulism survivors.

Ironically, the very mechanisms that make botulinum toxin so dangerous give it a wide range of beneficial medical applications. When botulinum toxin is administered in small, controlled doses, its muscle-contraction preventing effects make it a viable treatment for neck dystonia, sustained involuntary eyelid closure, chronic migraines, neurogenic bladder dysfunction, and other conditions caused by involuntary muscle movements. In popular culture and tabloid media, Botox’s serious medical applications are often overshadowed by its cosmetic notoriety: smoothing out wrinkles. Cosmetic Botox inhibits the neuromuscular activity that leads to wrinkles, relaxing the surrounding skin. Seeming to reverse one of the telltale signs of aging may have given botulinum toxin its Hollywood appeal, but its wide ranging pharmaceutical uses are what continue to fascinate research scientists.

In a nutshell, the molecule botulinum toxin is a toxic protein made by clostridium botulinum bacteria. In measured amounts, the toxic protein is marketed as Botox for pharmaceutical uses. When uncontrolled doses of the bacteria are ingested, however, Clostridium botulinum can result in deadly cases of muscle paralysis called botulism. 

 If you are intrigued by the terrible beauty of such a versatile molecule as botulinum toxin, come to Marin Science Seminar on September 30th, at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30 pm, when bioanalysis and pharmacology expert Dr. Erik Foehr will discuss his research on botulinum toxin.


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An Interview With Dr. Erik Foehr

By Zack Griggy, MSS Intern, San Marin High School, Novato

          In today’s world, infectious disease remains a deadly concern to humanity. Some of these diseases include anthrax, Venezuelian equine encephalitis, bubonic plague, MERS, Eastern equine encephalitis, and, of course, botulism. Botulism is a disease that can cause paralysis and even death, but what makes botulism so different from the rest of these diseases is that the substance that causes it, botulinum toxin, is widely marketed as a beauty product under the name Botox. Dr. Erik Foehr, an expert in the fields of bioanalysis, immunogenicity risk assessment, and drug development, is currently investigating the toxin and how the body responds to it. Attend his presentation at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30 pm on September 30th.

In order to gain a little more insight before his talk, we interviewed Dr. Foehr about his work and research.

1. What drew you into the fields of pharmacology and bioanalysis?
I have always enjoyed learning about biology and how living things work.  After high school at Drake, I went to UC Davis and studied genetics and biochemistry.  I eventually worked in the biotechnology industry and specialized in pharmacology and bioanalysis.

 2. What have you studied in the past and how did this lead to your study on botulinum toxin?

I studied cell biology and how cells signal and function. I also spent many years studying immunology.  In my current job I study how botulinum toxin works and test if people develop antibodies to the toxin.

 3. How is botulinum toxin used in beauty products? How are dangers minimized by these products?

Its a bit crazy to think something so dangerous can be used as a beauty product (it removes wrinkles).  The trick is to use a tiny amount and inject it at the site of the wrinkle. The toxin inhibits the neuro-muscular activity so that the skin looks “relaxed”. They are finding other more medically relevant uses of the toxin.
 4. What do you enjoy the most about your work? What do you enjoy the least?
I enjoy learning about the huge number of experimental new drugs being developed for unmet medical needs and helping to study them. Sometimes I would like to spend more time “thinking” and less time “doing”.
 5. Do you have any advice for high school students who aspire to be pharmacologists?
Study what interests you and be prepared to be a life-time learner. Science and technology move really fast and you need to adapt and learn on the go. Don’t get replaced by robots!
Join us Wednesday, September 30th, at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30 to hear Dr. Foehr talk about his work and his study on botulinum toxin and other lethal diseases. 
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