TED-Ed: Demodex mites, tiny arachnids living in human hair follicles, are harmless to most people and have co-evolved with humans.
TED: The video discusses the revival of traditional Polynesian voyaging techniques and the cultural significance of these practices.
CrashCourse: The video discusses the inadequacies of sex education in the U.S. and introduces a new comprehensive sex ed series by Crash Course.
TED-Ed - Yes, tiny mites live on your face — but is that a bad thing? - M. Alejandra Perotti
In 1841, Jacob Henle discovered tiny arachnids, later identified as Demodex mites, living in human hair follicles. These mites, specifically Demodex folliculorum and Demodex brevis, inhabit nearly everyone's skin, particularly on the face where oil glands are larger. They feed on oily secretions and are passed from mother to child during birth and breastfeeding. Mite populations increase after puberty due to hormonal changes. They are mostly harmless unless there's an immune dysfunction causing inflammation. Demodex mites have co-evolved with humans, and their genetic lineages can indicate human ancestry. Despite limited genetic diversity, they are not currently at risk of extinction.
Key Points:
- Demodex mites live in human hair follicles, especially on the face.
- They are mostly harmless unless immune dysfunction occurs.
- Mites are inherited from mothers and increase after puberty.
- Their genetic lineages can reveal human ancestry.
- Despite limited genetic diversity, they are not endangered.
Details:
1. 🔬 Discovery of Demodex Mites
- In 1841, German anatomist Jacob Henle discovered tiny, worm-like creatures in earwax, later identified as tiny arachnids.
- These creatures are part of a group of mites named Demodex, which includes over 100 species.
- Demodex mites inhabit and thrive in and around the hair follicles of mammals.
- The discovery of Demodex mites was significant as it opened new avenues in understanding parasitic relationships in mammals, leading to further research in dermatology and microbiology.
- Understanding Demodex mites has implications for diagnosing and treating skin conditions like rosacea and acne, highlighting their relevance in medical science.
2. 🧐 Human Hosts for Mites
- Nearly everyone is thought to host mites from at least one of the two Demodex species—Demodex folliculorum and Demodex brevis, which live specifically in human follicles.
- A single person's face might harbor hundreds or even thousands of these mites, living undetected.
- These microscopic arachnids are involved in a lifecycle of eating, mating, and laying eggs inside human pores daily.
- While mostly harmless, in some cases, mite activity can lead to skin irritation or conditions like rosacea.
3. 👶 Mite Lifespan and Human Interaction
- The difficulty of keeping Demodex mites alive off human skin poses challenges for scientific research, highlighting the importance of understanding their lifecycle and symbiotic relationship with humans.
- Mite ancestors developed and diversified alongside mammals, indicating a long evolutionary relationship that could provide insights into mammalian adaptation and health.
- Mites move into mammalian pores and feed on oily secretions in hair follicles, which plays a significant role in their survival and reproduction, affecting human skin health.
- Humans have their own specific follicular mites, suggesting a coevolutionary history that may influence human skin conditions and offer potential avenues for dermatological treatments.
4. 🌙 Mite Behavior and Nocturnal Activity
- Demodex mites are transmitted to babies through direct contact during birth and breastfeeding.
- After puberty, mite populations grow due to hormonal changes, increased oiliness, and immune responses.
- These mites primarily inhabit the face, targeting areas with larger pores and oil glands, such as around the nose.
- Their lifecycle spans approximately two weeks: one week to mature and an additional week of adult life.
- Mites are nocturnal, becoming active at night due to melatonin stimulation, coinciding with reduced human activity.
- Nocturnal mite activity may influence skin conditions by increasing exposure to mites when the human immune system is less active.
5. 🏃♂️ Mite Movement and Skin Health
- Demodex mites have lost genes for UV protection, adapted to living in pores and exploring in the dark, indicating a highly specialized lifestyle.
- These mites exhibit a movement speed of about one centimeter per hour on the face, primarily for mating purposes, demonstrating their localized activity.
- A single pore can host a family of around 14 mites, showing a significant population density on the skin, which is essential for understanding potential skin interactions.
- Demodex mites are universally present on human faces, suggesting their natural coexistence with humans without direct harm.
- Skin issues associated with Demodex mites are rare and usually involve additional factors, emphasizing the complexity of skin inflammation causes.
- Further research into the interaction between Demodex mites and the skin microbiome could provide insights into their role in skin health.
6. 🌍 Evolution and Genetic Diversity of Mites
- Immune dysfunction can cause inflammation due to a strong reaction or inadequate suppression of mite populations.
- Follicular mites are generally harmless for most people.
- Individuals tend to maintain their original mite lineages even when moving geographically.
- Different mite lineages have co-evolved with different human populations, potentially allowing ancestry to be determined through mite analysis.
- Mite populations' genetic diversity is limited due to restricted breeding opportunities from sticking with one host.
- This limited diversity might lead to eventual extinction, but this is a long-term possibility.
- The co-evolution of mites with human populations can help trace human migration and lineage.
- Follicular mites may play a role in skin health, balancing microbial populations.
- Understanding mite genetic diversity could improve insights into human health and ancestral links.
TED - What You Can Learn Crossing the Ocean in a Canoe | Lehua Kamalu | TED
The speaker, Leua Kamalu, a captain and navigator, explains the importance of traditional Polynesian voyaging canoes in connecting distant islands and preserving cultural heritage. Over time, the need for deep ocean travel diminished, and with colonization, much of the navigational knowledge was lost. In the mid-20th century, prevailing scientific views doubted the navigational skills of Polynesians, attributing their island settlements to chance. However, a team decided to revive these traditional practices by rebuilding canoes and learning ancient navigation techniques. This effort was supported by teachers like Mao, who helped navigate a newly built canoe to Tahiti in 1976, marking the beginning of modern Polynesian navigation. Kamalu, part of the third generation of modern voyagers, emphasizes the reliance on natural observations for navigation, highlighting the cyclical patterns in nature. She stresses the importance of understanding the impact of voyages on places and people, aiming to share knowledge and experiences for a better future.
Key Points:
- Traditional Polynesian voyaging techniques were crucial for connecting islands and preserving culture.
- Colonization led to the loss of navigational knowledge, with scientific views doubting Polynesian skills.
- A revival effort in the 1970s rebuilt canoes and relearned navigation, proving traditional methods viable.
- Navigators rely on natural patterns and observations, such as stars and weather, for guidance.
- Voyages aim to impact positively, sharing knowledge and experiences for cultural and personal growth.
Details:
1. 🌊 Embracing the Voyage: Unplugging and Unity
- Voyaging requires individuals to disconnect from digital devices, which can pose emotional challenges as it involves leaving behind familiar routines and interactions.
- To ensure a successful voyage, each participant must focus on understanding and executing their specific role effectively.
- The overarching goal of the voyage is to navigate the canoe successfully from start to finish, which necessitates teamwork and unity among all participants.
2. 🛶 Traditional Navigation: A Cultural Heritage
- Leua Kamalu is a captain and navigator specializing in traditional voyaging canoes.
- Her work is associated with the Polynesian Voyaging Society, emphasizing cultural heritage.
- The Polynesian Voyaging Society plays a crucial role in preserving traditional navigation techniques, fostering cultural pride and historical understanding.
- Traditional navigation is not just a method of travel but an integral part of cultural identity, connecting communities with their ancestral roots.
- The society's efforts have led to a resurgence in interest and respect for these ancient techniques, highlighting their relevance in contemporary times.
3. 🌺 The Decline of Polynesian Navigation
- Polynesian navigation originally played a crucial role in connecting distant islands via voyaging canoes, facilitating cultural exchange and resource sharing.
- Over time, the necessity for deep ocean travel diminished due to increased settlement and self-sufficiency of island communities, leading to a decline in traditional navigation practices.
- Technological advancements and the introduction of Western navigation tools further contributed to the decline, as reliance on indigenous methods decreased.
- The decline in navigation skills resulted in a loss of cultural heritage and traditional knowledge, impacting societal structures and inter-island relationships.
- Efforts to revive traditional navigation, such as the formation of groups like the Polynesian Voyaging Society, highlight the cultural significance and renewed interest in preserving these skills.
4. 📜 Reawakening Ancestral Skills: The Canoe Revival
- Colonization in Polynesia and Hawaii led to a significant decline in traditional navigational skills and canoe building due to the death of native Navigators and cultural suppression.
- Although traditional knowledge persisted in stories, the lack of practice resulted in skepticism about its authenticity and continued existence.
- The decline in population and cultural practices due to colonization critically endangered these skills, highlighting the need for a cultural revival to preserve and honor ancestral heritage.
5. 🚢 Reviving the Art of Navigation: A New Era Begins
- A prevailing narrative from the 1950s to 1970s suggested that Hawaiians or Polynesians lacked the skills to construct or navigate canoes, implying island settlement was accidental via drifting on winds and currents.
- A group challenged this narrative by planning to rebuild a traditional canoe and navigate it using ancestral methods, demonstrating intentionality and skill in Polynesian navigation.
- Teachers, including one named Mao, played a crucial role in educating the group in traditional navigation techniques.
- The newly built canoe, designed to replicate historical methods, was successfully sailed to Tahiti, showcasing the effectiveness of traditional Polynesian navigation.
6. 🌌 Navigating by Nature: Observations and Impact
- In 1976, modern voyagers revived traditional Polynesian navigation by launching the Hokulea, a historic Hawaiian canoe, without GPS or modern equipment.
- The speaker, part of the third generation and the first woman to solo navigate Hokulea traditionally in over 300 years, emphasizes the importance of these methods.
- Traditional navigation uses natural patterns, such as celestial movements, weather cycles, and ocean waves, requiring keen environmental awareness and all senses, including the scent of coconuts from islands.
- These voyages underscore the sensitivity to one's environmental impact and aim to leave a positive legacy for future generations.
- The goal is to not only navigate but also to share knowledge and experiences that contribute to a better future, demonstrating the practical and cultural significance of these methods.
CrashCourse - Crash Course Sex Ed Preview
The video highlights the lack of comprehensive sex education in the U.S., noting that only 29 states require some form of sex ed, and many do not mandate medically accurate information. Shan Boodram, a certified sex educator, emphasizes the need for better education, sharing her personal experiences with inadequate sex ed. The new Crash Course series aims to provide a more inclusive and accurate sex education, covering topics like STIs, pregnancy, orgasms, consent, and societal influences on sexuality. It also addresses gaps in current education, such as contraception and LGBTQ+ issues, promising a more engaging and informative approach.
Key Points:
- Only 29 U.S. states require sex education, and many lack medical accuracy.
- Less than half of U.S. states include contraception in sex ed curricula.
- LGBTQ+ topics are often excluded or misrepresented in sex ed programs.
- Crash Course offers a new series covering comprehensive sex ed topics.
- The series aims to be inclusive, accurate, and engaging for all learners.
Details:
1. 🚨 Catchy Introduction: Questioning Sex Education
1.1. The Ubiquity of Sex
1.2. Misinformation in Sex Education
2. 📊 The State of Sex Education in the US
- As of 2022, only 29 U.S. states required some form of sex education in schools, highlighting a significant gap in nationwide educational standards.
- More than half of these states did not require the information to be medically accurate, which poses risks for misinformation and ineffective public health education.
- The lack of mandatory standards for medically accurate information can lead to inconsistent and potentially harmful educational outcomes for students.
- In comparison, countries with comprehensive and medically accurate sex education often report lower rates of teen pregnancy and sexually transmitted infections, suggesting potential benefits of standardized education.
- Addressing the discrepancies in sex education can improve public health outcomes and provide young people with the necessary knowledge to make informed decisions.
3. 👩🏫 Meet Shan Boodram: Your Guide to Intimacy
- Shan Boodram is an AASECT-certified sex educator and an ABS-certified sexologist, holding a master’s degree in psychology.
- She is known for her role as the workshop teacher on the reality show 'Too Hot to Handle,' where she educates participants on intimacy and connection.
- Her journey into intimacy education began due to a noticeable lack of information on body awareness and consensual human connections, motivating her to fill this gap.
- Boodram has authored books and hosted digital content aimed at improving personal relationships and understanding of intimacy, making significant contributions to public discourse on these topics.
4. 📚 Personal Insights: The Flaws in Traditional Sex Ed
- Traditional sex education often provides incomplete and simplistic explanations, as exemplified by the anecdote of a fourth-grade class being told that sex is simply a tight hug between a man and a woman who love each other and want to make a baby.
- Individuals often find themselves seeking more comprehensive sex education outside of traditional systems, as seen in the example of using a library card to self-educate at the age of nineteen.
- The current state of sex education in North America is criticized for being dry, impersonal, and ineffective, similar to bad sexual experiences, leaving students disengaged and uninformed.
- Personal experiences highlight the inadequacies of traditional sex education, leading many to seek alternative resources for learning, such as books and online platforms.
- A broader critique suggests that traditional methods fail to engage students effectively, often resulting in misinformation and a lack of preparedness for real-life situations.
5. 🏫 Varying Sex Ed Across States and Inclusivity Issues
5.1. Contraception Education Gap
5.2. Inclusivity in Sex Education
6. 🎓 Crash Course's Innovative Approach to Sex Ed
6.1. Traditional and Societal Topics in Sex Ed Series
6.2. Societal Aspects and Educational Goals
7. 🔍 Exploring Complex Questions About Sex
- The lack of a male birth control pill reflects a notable gap in contraceptive options, highlighting ongoing gender disparities in sexual health responsibilities.
- Understanding the characteristics that define 'kinky' behavior sheds light on the diversity of sexual preferences, emphasizing the importance of inclusivity in sexual education.
- The questioning of the concept of virginity suggests it is a social construct, challenging traditional views and encouraging a more progressive understanding of sexual health.
- Crash Course Sex Ed provides educational resources to both newcomers and those experienced in sexual matters, aiming to enhance knowledge and promote informed discussions.
