Slow motion can be an invaluable tool in creating compelling scenes, but overuse of its use may make the scene unnatural and distract from what was intended. When overdone, however, slow motion may appear forced or artificial and lose its impactful qualities altogether. Many bridge cameras, DSLM camcorders and higher-end compact camcorders now allow users to record slow motion by saving high frame rate video directly into their final file.
The Human Genome
Researchers have made progress toward understanding a class of genes that shuffle about in the human genome using advanced statistical methods, leading them closer to unravelling its inner workings and possibly providing new insight into evolutionary processes, which could also have significant ramifications for diseases like cancer.
Researchers from the University of Illinois, Urbana-Champaign conducted research that involved analyzing DNA extracted from tumors that tend to produce more jumping genes than normal cells. Their team discovered that these LINE-1 and Alu-type jumping genes tend to land in areas of the genome where they may disrupt gene function or even trigger production of proteins linked with certain forms of cancer.
Jumping genes belong to a class of DNA sequences known as transposable elements, which can move through your genome more or less randomly and “copy themselves” across other areas. Some relics from early humans and four-limbed vertebrates have been passed down genetically while others were acquired via infection with viruses.
More than 50 years ago, Barbara McClinock from Cold Spring Harbor Laboratory in New York City first discovered that DNA sequences can move around freely within an organism’s genome. McClinock’s discovery challenged long-held beliefs that gene copies in an organism remain stable over generations and accurately reproduced by future generations.
Transposable elements (TEs), also known as jumping genes, were discovered to be widespread within human genome sequencing data and in most sequenced eukaryotic genomes to date, as well as occurring frequently among bacteria and simple eukaryotic organisms.
LINE-1 and Alu are the two most prevalent jumping genes. LINE-1 represents interspersed repetitive DNA, where repeated units of its repeat units appear randomly throughout the genome; Alu’s repeat units are more densely spaced out within tandemly repeated DNA.
U of I researchers utilized computational techniques similar to those employed by statistical physics researchers when simulating ecological interactions, to model how LINE-1 and Alu move through genome. Their models suggest that interaction between these elements resembles that of cuckoo birds: SINEs steal molecular machinery used by LINE-1 for copying itself, competing for scarce resources with it for survival.
The Human Brain
Human brains contain roughly 14-16 billion neurons that communicate via dendrites and myelinated axons – these transmit micro-electric signal pulses called action potentials to other parts of the brain or distant regions of the body, often for complex cognitive purposes such as planning, memory retention or self-regulation. Researchers in many fields including neuroscience, neurology and psychiatry have spent significant resources investigating our human minds in recent decades.
Researchers long believed there must be something unique to the human brain that makes us different from other mammals’ brains, something which allows us to do things other creatures cannot, like plan our lives, solve crossword puzzles and crack witty jokes. Perhaps this also explained why only humans experience severe conditions like schizophrenia and bipolar disorder.
Over the past several years, massive data streams from cell atlases, brain organoids and other techniques are providing answers to this age-old question. Scientists are learning that brain cellular architecture across species is strikingly similar and that most variance lies in how cells express genes rather than in actual sequence.
As humans have evolved, their brain has expanded significantly relative to body size. But it hasn’t done so uniformly: Certain brain areas relating to reasoning and language have seen particularly rapid expansion.
Brain development doesn’t end when someone reaches adulthood – in fact, it continues at a much faster rate than any other organ or tissue in their bodies. By the time a person reaches their late 40s, their brain has expanded more than sevenfold from what was expected when they entered middle age.
Human brains contain different cell types connected by nearly 100 trillion synapses – connections made of protein molecules which connect two neurons by binding to them – each neuron is capable of creating thousands of these connections to process sensory input, form new memories, and regulate bodily functions.
The Human Immune System
The human immune system is an intricate network of organs, cells and proteins that work to defend against infection by attacking microbes (germs). If any returning microbes return, their record will allow the immune system to recognize and destroy them quickly – any irregularities in this area could lead to allergic diseases, immunodeficiencies and autoimmune disorders.
Immunity is determined by an individual’s genetic make-up. Different gene variants have different risk levels for developing infectious and autoimmune disorders; consequently, different people respond differently to vaccines and medicines; individual differences also depend on environmental influences such as age, socio-economic circumstances and geographical location.
Researchers have recently demonstrated that human genome genes live an active life, adapting quickly to changing environmental conditions. Furthermore, researchers discovered that immune system subsystems each possess unique molecular properties which influence how it responds to infectious agents or vaccinations.
Jumping genes play a crucial role in genetic diversity, not only by creating mutations but also through transposons that move from part of the genome to another – these jumping genes comprise an estimated 30-40 percent of our genome but don’t always function at once.
Pancreatic cancer may be linked to LINE-1, an old gene with jumping properties. When this gene enters tumor cell DNA and jumps around activating production of its protein product LINE-1 can alter tumor growth or even make it resistant to treatment.
Other jumping genes may contribute to degenerative brain disorders, including Alzheimer’s. These transposon relics have been transformed into small RNAs which promote or restrict protein production or gene activity within cells.
The Human Embryonic Development
Fertilized human eggs embark on an extraordinary journey during the first eight weeks of gestation. From single-celled zygote to primitively functioning organs – known as human embryogenesis – during this period. Scientists are closely watching these early developmental stages with great interest as they may provide insights into fundamental biological processes responsible for healthy children and disease states such as achondroplasia, spina bifida, and first arch syndrome.
Researchers use serial sections of natural embryos to understand these events, with The Carnegie Collection of Embryos serving as an invaluable resource in their studies of human development. The Collection holds specimens preserved from ovulation through to week one of gestation, and are numbered accordingly. Furthermore, abnormal embryos provide valuable insight into causes of chromosome aneuploidy – a major cause of miscarriage and birth defects – providing important data that helps researchers better understand causes associated with miscarriage and birth defects.
Franklin Mall pioneered a method for staging embryos based on their morphological features in the early 20th century, which proved more accurate than assigning stages based on size or time since ovulation, both of which can differ by up to 50% in preservation fluid. His approach proved so effective that it remains used today to categorize embryos based on their characteristics rather than growth stage or time since ovulation.
At each week of gestation, embryos undergo the germinal stage – lasting from fertilization until implantation in the uterus – which involves various developmental events known as the germinal stage. At this stage, fertilized eggs undergo cleavage followed by morula formation before becoming implanted in the uterus as a blastocyst. Subsequently, gastrulation takes place whereby three germ layers develop through histogenesis, eventually reaching blastocyst status before implanting into its home uterus home for birthing.
A team led by Sozen has recently developed a model of human embryo development which they believe accurately represents early development of an average embryo. However, as part of its reductionist approach to studying natural human development this model shows great promise.
