Radioactivity and Nuclear Equations (Section)
The naturally occurring radioactive decay series that begins with 23592U stops with formation of the stable 20782Pb nucleus. The decays proceed through a series of alpha-particle and beta-particle emissions. How many of each type of emission are involved in this series?
Epigenesis- Dynamic system approach, life span development approach, how genes affect behavior, how experience reflects presentation of genes Interactions= bidirectional Chapter Four Early changes in body size Height Weight Girls are shorter and lighter in in infancy, have higher fat to muscle tone, Asian American smaller and African Americans larger than normal Trends in development Cephalcocaudal- head before arms & trunk before legs Proximodistal – control of head & trunk before arms and legs Changes in body proportions= hands and feet grow faster then body catches up with growth Brain Development Neurons and Synopses over produced- over abundance Excess eliminated-Synaptic Pruning OR Programmed cell death -Nature and Nurture Cerebral Cortex Dived into lobes, 85% of brains weight -frontal lobe= slowest to develop, responsible for cognitive development Lateralization= specialization of left and right brain hemispheres for different types of brain functions -left hemisphere= sensory info from & control of right side of body, verbal abilities, positive emotion, analytical processing -right hemisphere= sensory info from & control of left side of body, spatial abilities, negative emotions, holistic processing Corpus collousm unites both hemispheres Brain Plasticity Plasticity=changes to brain in respoinse to experience -during normal brain development -in response to brain injury -changes with age At birth hemispheres have already begun to specialize Highly plastic cerebral cortex has high capacity for learning If brain damaged, other areas take over tasks Older kids and adults retain some plasticity Sensitive Periods Experience expectant growth -Experience “expected” by brain for normal growth….vision easy to test from little vision to increased vision over time Experience dependent growth - Unique growth from specific learning experiences …. Taught to write, play musical instrument Orphan studies - Early prolonged insitituzionlization leads to: Decreased brain activity, high stress activity, attention deficits, impulsivity -high quality care can prevent deficits Changing states of arousal Sleep/ wake pattern moves to night/day… due to melatonin By 2 years, sleep drops to 12 hr/day Affected by cultural values -cosleeping ( bed sharing with infants) Influnece on early growth Heredity -MZ twins more alike in size than DZ Nutrition -breastfeeding vs. bottle-feeding -risks of overfeeding Malnutrition -20% of worlds children before age 5 Benefits of Breast feeding Correct balance of fat and protein -higher in fat and lower in protein nutrional compleeteness protects against disease… inhances immune function healthy physical growth…. Infants breastfed tend to grow faster in height in weight healthy dental development ensures digestibility…constipation rate= lower smooth transition to solid foods… expands flavors infant likes Malnutrition Marasmus -wasting condition -diet low in all nutrients…occurs in 1 year of life, not receiving enough nutrients in diet, if mother is also malnourished she cant give breast- milk to child -consequences: physical damage, learning deflects, behavioral effects, risk of death Kwashiorkor -diet very low in protein…calories come from starchy foods, abdomen swells -consequences: physical damage( lose hair, skin rash), learning deficits, behavioral affects -common ages 1-3 Food Insecurity -uncertain access to food -affects 21% of US children -consequences: poor physical growth, learning defeicits Motor Development Gross= control over actions that help infants get around enviorment Fine- control over smaller movements (reaching and grasping) Motor development as dynamic systems - mastery involves acquiring increasingly complex systems of action - motor skills as a system: - CNS development, Bodys movement capacities, childs goals, enviormental support Milestones Hold head erect when upright - Average 6 weeks - Range 3 weeks-4 months Lift self by hands -average 2 months range 3 weeks - 4 months Rolls from side to back -average 2 months -range 3 weeks-5 months Rolls back to side -average 4.5 months -range 2-7 months Sits alone -average 7 months Crawls -average 7 months -range 5-11 months - Standard - Army - Inchworm - Bear - “bum shuffling” - spider - log roll Pulls to stand -average 8 months -range 5-12 months Walks alone -average 11 months, 3 weeks -range 9-17 months - Walking -intermediate movements -experimenting with balancing on feet can lead to less stability sitting Reaching and Grasping Pre-reaching -birth- 7 weeks -poorly coordinated swipes Reaching -2 hands= 3-4 months -1 hand= 7 months Ulnar Grasp -Fingers close against palm -Adjust grip to object -4-5 months= move objects from hand to hand Pincer grasp -use thumb and index finger opposably -9 months Thelen and collegaues -motor development as dynamic system -lontiudinal research -when infants first reach movment is jerky, but by end of first year movement is smoother and straighter White and held (1966)- having stimulation leads to early reaching (moderate reached 6 weeks earlier than massive stim) -connection b/w stimulation and onset of reaching -instituinalized infants --control, moderate stim, massive stim -more stim= more crying Dennis (1960) -Iranian orphans -uninteresting cribs -do not move on own until about 2 years old -at 3-4 years of age were only 15% were walking alone Cultural variations in motor development Rates and patterns of development affected by; -early movement opportunities, environmental stimulation, child- rearing practices Learning in Infancy