Term Paper About Tardiness

School engagement and participation have become the focus of educators over the past decade as they are linked to achievement and dropout rates. In order to learn, a student has to be both physically and mentally present in the classroom, on a consistent basis, ready to receive instruction.Students who are in class, on time, and behaving well are more likely to be actively and productively engaged in their own education. Conversely, students who are moving frequently between schools may be less likely to be engaged in their learning, much like a student who is frequently absent.Additionally, a high rate of mobility at a particular school can adversely affect every student at that school. Measures of engagement and participation vary; however, research has proven that high rates of absenteeism, tardiness, disciplinary incidents, or mobility signal disruptions in the continuity and quality of a student’s learning.Moreover, high rates of absenteeism can lead to course failure and , eventually, dropping out of school. The good news for educators is that all of this student information is accessible early and often in the school year, before course performance data is available.As a result, these data are powerful and useful early indicators for identifying students in need of immediate intervention. In the case of a student who is receiving interventions engagement and participation measures can also provide educators with an important measure of the â€Å"dosage† of the intervention.When viewed together, attendance, tardiness, discipline, mobility, dropout rate and participation metrics help educators understand the true story of how actively and productively individual students, groups of students, and their parents are engaged in school.

Biol 130 First Midterm Notes

Unit 1 – Introduction to the Cell Robert Hooke – built the first microscope (30x magnification); viewed slices of cork called cellula (little rooms). Antoni Van Leeuwenhoek – worked with glass huge improvement in quality of lenses nearly 300x magnification became possible first to observe: * single-celled organisms â€Å"animalcules† * protists from pond water * bacteria from his mouth – â€Å"father of microbiology† * blood cells * banded pattern in muscle cells * sperm from †¦ 1830s – Compound microscope – improved magnification and resolution and allowed visualization of objects less than 1 ? . 1000-1500x magnification Beginning of Cell Theory Robert Brown (botanist) – noticed that every plant cell contained a round structure called it ‘kernel’-nucleus Matthias Schleiden (another botanist) – all plant tissues are composed of cells; embryonic plant always arose from a single cell Theodor Schwann (zoologist) – similar observations in animal cells; recognition of structural similarities btw plants and animals! * Cell Theory formulated by Schwann Cell Theory 1. all organisms consist of one or more cells 2. he cell is the basic unit of structure for all organisms 3. added 20 years later: all cells arise only from pre-existing cells fact (scientific) – an attempt to state our best current understanding, based on observations and experiments(valid only until revised or replaced) Steps in Scientific Method 1. make observations 2. use inductive reasoning to develop tentative explanation (hypothesis) 3. make predictions based on your hypothesis 4. make further observations or design and carry out controlled experiments to test your hypothesis 5. nterpret your results to see if they support your hypothesis Theory – a hypothesis that has been tested critically under many different conditions andby many different investigators . using a variety of different approa ches. By the time an explanation is regarded as a theory it is widely accepted by most scientists in the cell * the â€Å"solid ground† of science: evolution, germ theory, cell theory *If a theory is thoroughly tested and confirmed over many years by such large numbers of investigators that there is no doubt of its validity †¦ it may eventually be regarded as a law.Gravity, laws of thermodynamics, laws that govern behaviour of gases ‘Strands’ of Cell Biology 13 cytology 1600s Hooke looks at cork Leeuwenhoek looks at lots of things 1800s Brown notes nuclei bio-chemistry synthesis of urea in lab fermentation done by cells! glycolysis Krebs cycle every cell comes from a cell Schleiden & Schwann formulate cell theory electron microscopy stains & dyes genetics Mendel, pea plants DNA chromosomes chromosome theory 1930s DNA double helix DNA sequencing Dolly the sheep! nano-technology! genetic code Light Microscopy:Bright field – light passes through specimen , contrast is slow and specimen is hard to see Phase contrast – contrast is changed by changing light in microscope DIC – uses optical modifications to change contrast between cell and background – due to density differential Staining – stain used to visualize cell and components, only some stains can be used on living cells 14 bright field phase contrast DIC unstained (sperm cells) stained blood cells tissue – small intestine Fluorescent Microscopy – fluorescent dyes bind to protein or DNA to see where they are in cells – tracks movement Electron Microscopy(Scanning & Transmission):SEM – scan surface of specimen to form image by detecting electrons from outer surface. Good surface images TEM – forms image from electrons passing through specimen therefore fine details of internal organelles 16 SEM TEM Basic Properties of Cells: * are highly complex and organized * atoms molecules macromolecules (organelles ) enclosed in plasma membrane * use the same ‘genetic program’ Central Dogma * DNA RNA protein * are capable of reproducing themselves * must first replicate genetic material acquire and use energy (â€Å"bioenergetics†) and carry out a variety of chemical reactions (â€Å"cellular metabolism†) * have many processes that are highly conserved at the molecular level * membrane structure, genetic code, ATP synthesizing enzymes, actin filaments, eukaryotic flagella, †¦ * engage in many mechanical activities * transport of materials in/out, within * assembly and disassembly of structures * motility / movement * respond to environmental signals * move away or toward stimuli * respond to hormones, growth factors, etc * are capable of self-regulationâ€Å"homeostasis† most evident when control systems break down; defects in DNA replication, DNA repair, cell cycle control Two Classes of Cells – karyon = nucleus Prokaryotic Cells: lack of nucleus, NO CYTOSKELET ON(very small), membrane bound organelles. Mostly unicellular. Bacteria and Archaea. Single, circular strand of DNA(fewer proteins). Cell wall in addition to PM 1-10 uM in diameter. 2 types: 1. Eubacteria – all have cells walls except for mycoplasma(resistant to antibiotics that target cell wall synthesis). Mycoplasma(smallest) Cyanobacteria (largest and most complex). 2.Archaeabacteria – all have cell walls and are known as extermophiles, occupy broad range of habitats, halophiles=salty, acidophiles=acid, thermophiles= hot. Eukaryotic Cells: 10x larger than prokaryotic cells, membrane bound nucleus/organelles. More complex DNA due to histones/proteins. 4 groups: 1. Protists- very diverse group – mostly single cells; algae, water molds, slime molds, protozoa 2. Fungi – single cell(yeast) or multi-cellular(mushrooms) and have cell walls. Heterotrophs; depend on external source of organic compounds 3. Plant cells- multi-cellular and have cell walls. . Anima ls- multi-cellular, no cell walls and are heterotrophs Cytoplasm – everything between plasma membrane and nuclear membrane, includes all membrane-bound organelles (except nucleus) Cytosol – only fluid component Endomembrane system – internal membranes that are either in direct contact or connected via transfer of vesicles (sacs of membrane). including: nuclear envelope / membrane, endoplasmic reticulum (ER), Golgi apparatus, lysosomes, vacuoles Nucleus – stores genetic information Endomembrane System – creates intracellular compartments with different functions.Endoplasmic reticulum (ER; rough, smooth), Golgi apparatus, lysosomes. Mitochondria – generate energy to power the cell Chloroplasts – capture energy from sunlight, convert to carbohydrate Cytoskeleton – regulates cell shape, movements of materials within the cell, movement of the cell itself Flow of Traffic in EMS – Rough ER: synthesis of proteins for – ex port (secretion) – insertion into membranes – lysosomes Golgi apparatus: collection, packaging & distribution Lysosomes * cell ‘stomachs’ have enzymes that can digest †¦ * all 4 classes of biological macromolecules worn-out organelles (mitochondria replaced every 10 days) * material brought into cell by phagocytosis Phagocytosis – plasma membrane engulfs smaller molecule and then called phagosome. Lysosome takes it in and digests, small particles are releases into the cytoplasm. Autophagy – lysosome digests a damaged organelle, small particles are released into cytosol. mitochondria (all eukaryotic cells) and chloroplasts (plant cells): * contain DNA that encodes some (but not all) of their own proteins * have unusual double layers of membranesOrigin of Eukaryotic Cells: Endosymbiont Theory * once believed that eukaryotes evolved gradually, organelles becoming more and more complex * now accepted that early eukaryotes originated as preda tors * certain organelles (mitochondria, chloroplasts) evolved from smaller prokaryotes engulfed by larger cell * later chloroplasts and the ability to perform photosynthesis Symbiosis – Mutual Advantage advantage to host cell: * aerobic respiration (aerobic bacteria mitochondria) * photosynthesis (cyanobacteria chloroplasts) advantage to bacteria: * protected environment supply of carbon compounds from host cell’s other prey Evidence Supporting Endosymbiont Theory mitochondria and chloroplasts †¦ * are similar size to bacteria, reproduced by fission like bacteria * have double membranes, consistent with engulfing mechanism * have their own ribosomes, which resemble those of prokaryotes rather than eukaryotes in terms of size, composition and sensitivity to antibiotics * have their own genomes, which are organized like those of bacteria last but not least: * are genetically similar to proposed ‘parent’ bacteria rather than ukaryotic cells Cytoskeleton important in: * cell shape * cell motility * movement / position of organelles * movement of materials within cell * movement of chromosomes during mitosis Cytoplasm in a living cell is never static * cytoskeleton is constantly being taken apart and rebuilt * organelles and vesicles are racing back and forth * can cross the cell in ~ 1 second * unattached proteins moving randomly, but rapidly * can visit every corner of the cell within a few seconds * contents of cytosol are in constant thermal motionCommon to all cells: * selectively permeable plasma membrane * genetic code; mechanism of transcription and translation * ATP for the transfer of energy and metabolic pathways Model Organisms 45 Unit 2a – Intro to Cellular Chemistry Most Common Elements in Living Organisms: * C H O N – make up 96% – also P and S are common too * Exist as complex macromolecules and simpler forms like water and carbon dioxide nucleus – dense core in centre, consists of protons and neutrons electrons – continually orbit the nucleus # of protons – defining feature of an element = atomic number – # protons + # neutrons = mass of an atom = mass number – by default, an atom is ‘neutral’, with # protons = # electrons – electrons influence reactivity of an atom †¦ Atomic mass = atomic number + # of neutrons (electrons are neglected because mass is so small) Isotopes – same number of protons but different number of neutrons in the same element Anion – gain electron and are negatively charged Cation – lose electron and are positively chargedOutermost ‘valence’ shell influences an atom’s reactivity * electrons in outermost shell valence electrons * unpaired valance electrons determine the number of bonds an atom can make * atoms with filled valance shell = most stable, atoms that are closest to filling are most reactive * elements abundant in organisms have at least one u npaired valence electron Some Definitions: covalent bonds – two or more atoms share pairs of valence electrons * strong bonds of biological systems non-covalent bonds, including * ionic bonds * hydrogen bonds (H-bonds) * hydrophobic interactions olecule – group of atoms held together by energy in a stable association compound – molecule composed of two or more different types of atoms Types of Covalent Bonds * electrons shared ‘equally’ * non-polar covalent bond * can be single (like H2), double (O2) or even triple, depending on number of electrons shared * electrons not shared equally * polar covalent bond * one of the atoms has a stronger pull on the electrons than the other * pull on electrons = electronegativity * water is the most abundant molecule in biological organisms * human body is ~70% water water as a solvent can dissolve more types of molecules than other molecule known * the polarity of water is key to its role in biology hydrogen bon ding – electrical attraction between electronegative atom and partial positive of hydrogen hydrophobic – no affinity for water – â€Å"water fearing† hydrophilic – affinity for water – â€Å"water loving† Acid-base Reaction substance that gives up (donates) protons acid (increases [H+] in solution) substance that accepts protons base (decreases [H+] in solution) chemical reaction that involves transfer of protons acid-base reaction * most olecules act as either an acid or a base * water can be both (both gives up and accepts protons) weak acid: very few molecules dissociated (acetic acid, water) strong acid: readily gives up protons (hydrochloric acid) when pH = pKa species is 50% ionized Carbon is the most important element in biology carbon atoms give biomolecules their shape but other atoms attached to carbons determine their reactivity * critical H, N, O containing attachments called functional groups *learn orgo functional groups for this courseMacromolecules * large, organized molecules that are typically created by polymerization * biological macromolecules (biomolecules) provide the structure and carry out the activities of a cell 4 groups: * carbohydrates(polysaccharides) * lipids(fats) * proteins * nucleic acids * monomers of groups are different – chemical reactions used to make the chains are similar Overview of Macromolecules 3 Proteins – more functions than any other group of macromolecule * enzymes – catalysis; accelerate chemical reactions transport – through cell membranes, in circulation * support – cytoskeleton, fibres of cartilage, hair, nails * signalling / regulatory – hormones, membrane proteins, intracellular messengers * movement- of the cell itself – contractile proteins, flagella – within the cell – motor proteins * defense – antibodies, complement proteins Proteins are Polymers * amino acids are connected in linear polymers of a specific sequence * 20 genetically encoded amino acid monomers to pick from * string of amino acids (AAs) = peptide or polypeptide polypeptide folded and coiled into a specific conformation = protein * sometimes 2 or more peptide chains (subunits) combine to form mature, functional protein Amino Acid Structure AAs are ionized under physiological conditions ionization increases solubililty, facilitates interactions with each other and other solutes, increases reactivity (zwitterions) 7 non-ionized ionized R group unique to each AA oxygens tend to pull electrons away, making it easy to lose proton gains a proton Amino Acid Side Chains – R Groups: * nonpolar – hydrophobic R groups no charged or electronegative atoms to form H bonds * insoluble in water * R groups bury themselves with the peptide chain to ‘hide’ from water * polar side chains – soluble in water * uncharged – but partial charges can form H-bonds * charged – gr oups containing acids or bases – highly soluble in water AA are linked together by covalent peptide bonds: carbon from carboxyl group is linked to N terminus of amino group. R groups and central C’s do not participate in the bond. Condensation Reaction – making the chain Hydrolysis – breaking the chain Polypeptide chain: side chains extend from peptide-bonded backbone * chain is flexible – can rotate at single bonds on either side of peptide bonds * so side chains are not all projecting to one side! * chains can be from 2-3 to thousands of AAs in length * backbone is directional, convention is to number AA ‘residues’ starting at N terminus this is the primary sequence Sickle Cell Anemia – disease in which red blood cells are abnormally shaped. Caused by single point mutation which results in substitution of single amino acid in one chain of hemoglobin protein Protein Structure:Primary Structure – unique sequence of amino acids Secondary Structure – Folding into elements of structure, hydrogen bonding between amino acids(R groups not involved). 2 shapes: alpha helix and beta pleated sheet(parallel and antiparallel). * learn more Tertiary Structure- interactions of elements of secondary structure forming a global fold, folded into these unique shapes by ionic bonds (electrostatic),hydrogen bonds, disulphide bridges, hydrophobic interaction, van der waals – dipole-dipole(all non-covalent except for S-S). Order of amino acids determines final shape.Maintain globular shape even if very weak. Quaternary Structure – more than one polypeptide chain put together to form the final functional protein, linked by covalent and non-covalent interactions. Protein Domain – segment of polypeptide that forms a compact, stable and independently folding structure. Often the building blocks for larger, more complex proteins. Disulfide bonds * covalent stabilization of protein structure found i n secreted proteins (destined for a more hostile extracellular environment) * formed in ER (oxidizing environment)Once folded, do proteins ever unfold? changes in physical or chemical conditions (pH, salt concentration, temperature) disruption of H-bonds, ionic bonds, disulfide bridges, etc that maintain the protein’s shape protein ‘denatures’ or unfolds Possible to renature Do proteins ever fold incorrectly? any mutation that leads to a missing or incorrect amino acid can lead to incorrectly folded protein WHY 32 Possible outcomes: mutation – leads to incorrectly folded protein * protein never functions properly loss of function protein folds properly at first but unfolds under certain conditions eventually loss of function * protein misfolds AND is deposited in insoluble aggregates within cell * loss of function and disruption of other aspects of cell activity * many human diseases now known to be associated with misfolded proteins . Alzheimers, cystic f ibrosis, type II diabetes, retinitis pigmentosa, Parkinsons, Creutzfeldt-Jakob, some cancers *read about catalysts and enzymes in Janelle’s notes, page 8-9 Nucleic Acids: Information Polymers * deoxy ribo nucleic acid (DNA) sequence of subunits in DNA polymer directs RNA synthesis * ribo nucleic acid (RNA) * RNA directs ordering of AAs in a peptide chain * information stored as DNA sequences enables living organisms to pass on hereditary information * also allows each cell to pass on hereditary information to the next generation of cells Monomers of Nucleic Acids: Deoxyribo nucleotides – phosphate + deoxyribose + nitrogenous base(A,C, G, or T) Ribo nucleotides – phosphate + ribose + base (A,C,G, or U) Nucleic acids are linear (unbranched) polymers of nucleotides * each nucleotide consists of three parts: * a nitrogenous base a (5-carbon) pentose sugar * a phosphate group Purines = A&GPyramidines= C,T and U * Ribose + base = nucleoside * Ribose + base + phosphate = nucleotide Functions of Nucleotides * monomeric units of RNA and DNA * important signal molecules within cells * cyclic adenosine monophosphate (cAMP) * important agents in energy transfer reactions * cleave off phosphate group to release stored energy * act as coenzymes – organic non-protein molecules required for enzyme function * usually adenine-containing nucleotides combined with B vitamins 8 condensation reaction 5’ end – beginning of chain. Chains always built 5’ 3’.Look at above example phosphate group is 5’ 3’ end – where new bases can be added Polymerization rxn’s are endergonic: * making phosphodiester bonds requires energy * energy comes from addition of 2 phosphate groups. * Activated nucleotides = nucleotide triphophates The most famous phosphorylated nucleotide †¦ adenosine triphosphate = ATP 11 adenine 4’ 5’ 5 6 1 2 3 9 4 8 7 1’ 3’ 2’ O P CH2 O O O– P O O O– P O –O O– OH OH O NH2 N N N N ribose adenine + ribose (= adenosine) Secondary Structure of DNA: two strands of DNA align in ‘antiparallel’ arrangement with bases facing inwards. H-bonds form between bases. P P P P P P P P C C G G AA T T P O O O O O O O O O O O C G OH P Note: 3 H-bonds between C and G, 2 between A and T. Only space in the sugar phosphate backbone is for Pyramidine and Purine to bond together. Features of DNA Double Helix * stabilized by H-bonds between complementary bases and hydrophobic interactions between bases * entire molecule water-soluble because charged phosphates backbone face outward * major and minor grooves are significant in regulation of gene transcription Higher Order DNA Structure: DNA molecules can adopt higher order structure – Allows for compact packaging and strict regulation of gene expression RNA vs DNA like DNA: sugar-phosphate backbone covalently linked by phosphodiester bonds * 4 different bases unl ike DNA: * uracil (U) instead of thymine (T) * pairing is A-U, C-G * sugar is ribose instead of deoxyribose * hydroxyl group makes ribose much more reactive * RNA is much less stable than DNA Secondary Structure of RNA: like DNA: * H-bonds form between complementary base pairs unlike DNA: * most of the time, this base-pairing is between bases on the same strand * leads to formation of ‘stem and loop’ structures with single-stranded regions and double-stranded antiparallel regions * H-bonding is spontaneous, stabilizes the molecule final molecule is single-stranded * Complex folds can result in some RNA having catalytic activity Carbohydrates * Group of molecules that contain carbon, hydrogen and oxygen in a 1:2:1 ratio: (CH2O)n Only monomers are in this ratio, oligomers you lose water * Monomer=monosaccharide * Dimer=disaccharide * Trimer=trisaccharide/oligosaccharide Types: 1. Monosaccharides – simple sugars 2. Oligosaccharides – small chains (oligo=few) * Attached to proteins – glycoproteins * Attached to lipids – glycolipids 3. Polysaccharides – very long sugar chains Typical Structural Features of Sugar Monomers: carbonyl group (either ketone or aldehyde) * lots of -OH groups * vary in length of carbon skeleton (C3, C5, C6, †¦) – triose, pentose, hexose * isomeric forms (glucose, fructose, galactose) * identical chemical groups arranged differently * monosaccharides often form rings in solution Isomers – same atoms, different arrangements structural isomer – identical groups but bonded to different carbons stereo (optical) isomer – identical groups bonded to same carbons but in different orientations sixteen different hexose structures possible, all with formula C6H12O6 C OH C OH OH H C OH H HO C H C O H C OH H H C OH H C OH H C OH H HO C H H C OH H structural isomer stereo- isomer H C C O HO C H H C OH H C OH H HO C H H C OH H fructose glucose galactose *arrangement of hydrox yl groups make a big difference in biological function Disaccharide – 2 sugar monomer: * glucose + fructose = sucrose(table sugar) * glucose + lactose = lactose * glucose + glucose = maltose Formation of disaccharides by condensation reactions. monomers are linked when C1 of one monosaccharide binds to a C on another – often C4 geometry of bond different depending on hether OH group of C1 is in ? or ? position which C of other sugar is involved in linkage 7 C1, ? C4 ?-glucose ?-glucose maltose, ? -1,4 glycosidic bond ?-galactose ?-glucose lactose, ? -1,4 glycosidic bond (glucose has flipped over) C1, ? C4 Polymerization to build Polysaccharides starch both are storage forms for energy starch – plants; glycogen – animals both consist of ? -glucose monomers linked by ? -1,4 bonds both coil into a helix (due to geometry of linkages) starch is mixture of unbranched amylose and branched amylopectin glycogen is highly branched lycogen Structural Polysaccharide in Plants: Cellulose 9 polymer of ? -glucose, joined by ? -1,4 linkages each glucose is flipped relative to adjacent ones allows for H-bonding between adjacent strands extremely stable most abundant organic molecule on earth parallel strands joined by H-bonds Structural Polysaccharide in Animals: Chitin a component of cell walls of fungi, exoskeletons of arthropods (insects, crustaceans), radulas of molluscs, beaks of cephalopods second most abundant organic molecule on earth like cellulose, joined by ? 1,4 linkages but rather than glucose, monomer is N-acetylglucosamine like cellulose, also strengthened by H-bonding btw strands 10 Structural Polysaccharide in Bacteria: Peptidoglycan component of bacterial cell walls the most complex CHO so far! two different alternating monomers linked by ? -1,4 bonds chain of amino acids attached to one of the sugars – peptide bonds instead of H-bonds (stronger) Significance of how monosaccharides are linked: * ? -1-4 linkages of starch and glycogen readily hydrolyzed * ? 1-4 linkages in structural polysaccharides very resistant to enzymatic degradation For example: enzymes that digest cellulose (cellulase) produced only by certain classes of bacteria, fungi and protozoa Difference between glycosidic bonds from peptide and phosphodiester bonds: in common: * condensation reactions different: * peptide and phosphodiester bonds always occur at the same position within their monomers * each sugar monomer has several hydroxyl groups, and geometry of glycosidic bonds is highly variable Functions of Carbohydrates: Structural: * cellulose, chitin and peptidoglycanCell-cell recognition: * membrane proteins covalently bonded to oligosaccharides Energy Storage * ? -1,4 –linkages of starch and glycogen are readily hydrolyzed to release stored energy Lipids * group of carbon-containing compounds that are largely non-polar / hydrophobic * significant proportion of a given lipid molecule is hydrocarbon * the only macromolecul e that is not a polymer major groups of lipids in cells: * fats / oils – energy storage * sterols * cholesterol – membrane component * steroids – hormones * * Phospholipids * major component of biological membranesFats (Triacylglycerols, Triglycerides) * form that fat is stores in apidose tissie * glycerol with 3 fatty acids attached * the link between glycerol and fatty acid = ester bond: condenstation rxn (liberates water) * hydrophobic * fatty acid(carboxylic acid with long hydrocarbon tail) Saturated Fatty Acid – have maximum number of hydrogen atoms on each atom; straight and flexible because of only single bonds Unsaturated Fatty Acid – contain at least 1 double bond. The double bond is rigid and creates a kink in the chain. The rest of the chain however is free to rotate about C-C bonds.Cis – H on the same side of double bond; don’t solidify easily Trans – H on the opposite side of the double bond. Hydrogenation – making a fat saturated/more solid at room temperature to improve shelf life therefore less healthy. Sterols – group of steroids based on cholesterol(important component of cell membrane) Phospholipids : * 1 glycerol, 2 fatty acids, 1 phosphate group(polar head group) * Amphipathic = hydrophilic and hydrophilic regions – their most important feature with respect to biology Micelles – sphere with hydrophobic tails ‘hiding’ in centre . Can only occur with relatively short tails Lipid Bilayer:Universal Structure for all Biological Membranes composition varies with: type of organism (prokaryote vs animal vs plant vs †¦) type of cell within organism (muscle, liver, sperm, egg, †¦) type of membrane within cell (plasma membrane, Golgi, ER) inner versus outer layer different patches or ‘domains’ within a particular membrane Fig 11-4 two closely apposed sheets of lipids, studded with proteins lipids serve as permeability barrier protei ns perform most of the functions carbohydrates (sugars) attached to protein and lipids in a non-random manner *all membrane lipids are amphipathic Lipid bilayers form spontaneously: hydrophobic molecules would exclude water, clustering together to minimize energy cost of organizing water molecules * form large droplets or surface film * amphipathic molecules are subject to conflicting forces * solved by formation of bilayer * energetically most favourable stable, spontaneous * lipid bilayers are †¦ * closed – no free edges * self-sealing * important feature for cell fusion, budding, locomotion Fluid Mosaic Model * The plasma membrane is described to be fluid because of its hydrophobic integral components such as lipids and membrane proteins that move laterally or sideways throughout the membrane.That means the membrane is not solid, but more like a ‘fluid'. * phospholipids are constantly moving spinning in place; travelling laterally within ‘leaflet’ * phospholipids are occasionally ‘flipped’ to the opposite leaflet during membrane synthesis but they rarely ‘flop’ back * even proteins cruise slowly through the membrane! Membrane fluidity – how easily lipid molecules move within a membrane leaflet Alignment of phospholipid tails * tightly packed tails membrane more viscous, less fluid * freely moving tails higher fluidity What aspects of phospholipid composition influence this? length of fatty acids * from 14-24 carbons, 18-20 carbons most common * degree of saturation of fatty acids # double bonds * typically one saturated fatty acid and one with one or more double bonds Cholesterol: * under physiological conditions, cholesterol makes membrane stiffer – less fluid * cholesterol can make up to 50% of plasma membrane lipid in some animal cells Regulation of Membrane Fluidity: – fluid state must be maintained for normal cell function strategies for maintaining membrane fluidity: * chang e composition of membranes * alter phospholipids desaturate fatty acids (to deal with cold) eg cold water vs warm water fish * change length of FA chains (yeast, bacteria) * adjust amounts of cholesterol (animals) these mechanisms have been demonstrated in: * pond fish dealing with dramatic day / night temp differences * cold-resistant plants * extremophile bacteria living in hot springs * winter wheat preparing for autumn ^ polyunsaturated FAs * sperm reduce their cholesterol just before fertilization †¦ Functions of Lipids: * storage of chemical energy * signal molecules * vitamins * wax coating on leaves * biological membranes

Department of Peace Essay

1 Internet is always been a source of information. With just one click, all the information you want to know is right in front of your eyes. It always caters to different topics such as: academics, religion, sports, entertainment and even politics. Today, there is probably hundreds of website that discuss about politics and their relevance to national issues. Such website provides information on what they do and on what they will do in the future. A site of the â€Å"U. S. Department of Defense† provides information that caters the entire American citizen. It allows every concern people to have an access or information regarding the department of U. S. defense. Also, the site enables its reader to have an idea or knowledge about the service that the government is doing for them. It provides different links as to explain everything that the defense is responsible of and to give its readers a chance to understand clearly its purpose. The site actually convinces its readers that the U. S. Department of defense’s main goal is to protect the countrymen. Definitely, the site is successful in inducing the citizen to join and unite as one for peace and humanitarian services through the information they have provided. The site was able to affirm that it is there duty to serve and defend the American people whether saving lives or spreading peace in the community. The values are still in tack and the need to share all the information was manifested clearly in the site. They do not only provide the purpose, mission and vision of the department but they have successfully managed to disseminate information through the site. The U. S. Department of Defense official site is convincing primarily because it showed what the people would want to know. Amidst politics intrigues, the department remains stand still and still uphold to its virtues. The use of this site for understanding the duties and responsibilities of the department gives its reader the capacity to make good judgment and to support the department’s mission and vision. Indeed, the site provided by the U. S. department of defense is capable of persuasion because of its plain and truthful explanation of its purpose and of its current activities that is for the betterment of the country. 2 Another site is the â€Å"U. S. Department of Peace† that also caters for the American people. While the department of defense serves for defending its countrymen and for building peace, the U. S. Department of Peace develops programs and campaigns as to promote peace and for national interest. There main goal is to â€Å"take the field of peace building from the margins of the political† and hopefully, bring it to a better place. They intend to apply peace building as to lessen all the conflicts before it gets even worse. The site also provides ample information regarding the association from its mission, vision, goal and their current focus today. The site indicated that the association is not just about the politics but mainly it’s about the effective and practical way in promoting and developing peace. In the site, they’ve explained that the U. S. department of peace is an association that encourages citizen activist to join in building peace for a prosperous nation. Their intention as a peace alliance is well explained in the site because they have indicated their campaigns, programs and activities. Their means of persuading its readers is credible because they have explained point by point their mission and their plans. At first visit to the site, you’ll automatically recognize that they encourage everyone to subscribe holiday cards and at the same time support the work of the peace alliance. In that way, they encourage the readers to support their campaign and offer them such good card. The use of this technique is probably a best way to encourage people since holidays is fast approaching. Nonetheless, the U. S. department of peace is an association that continue to grow as they progress and plan campaigns. Through the help of volunteers and activist, they continue to develop and put into works all of the association’s plan and goal. The use of the internet to promote the association is one of the best way to explain their purpose as an association and as well as to have a discussion board to all the concern people and to those who wanted to support. Indeed, the site also provided the necessary information and they were able to persuade its readers through their truthful agenda and well explained purpose. 3 A related site entitled â€Å"U. S. Peace Government† is about preventing war and terrorism and promotes peace. The site is for promoting peace and establishes peace-creating groups for the nation and other states. The U. S. peace government is pro-peace and in the site they clearly illustrated their purpose. The peace government is composed of hundreds of American scientist and researchers in medical field. These scientist and experts are capable of strong commitment in terms of leading the nation to peaceful direction. The site also includes the introduction of different programs for developing peace. Their ways of promoting peace in its realistic ways is explained in the site. The main purpose of the site is to share to its reader the possible effect of permanent peace if they developed their programs. Their goal as an organization is very simple and they need not to compete with existing governments but instead they will try to prevent problems from occurring. Upon reading the site, you’ll notice that it is trying to persuade its readers by laying all the facts and there agenda as an organization. Their way of imparting information to its readers is clearly manifested in the site. It also includes their stand and perceptions on the current issues that the government is experiencing now. As said, they are not merely a â€Å"policy think tank† but they will contribute to the development of peace in the country. The site has transformed the association’s mission into a realistic way because they put more information about their goal rather than discussing about other matters. They intend to spread peace all over the nation and lessen the conflict. Indeed, the association has come along way in promoting their mission because there is improvement in the nation. 4 â€Å"Daily Kos† is an on-line blog that tackles about the political issues that the present administration is facing now. Contrary to the previous site that was discuss, Daily Kos is far from what those site is all about. The blog talks about the opinions and the suggestions of different writers who share their thoughts fearlessly without hesitations and doubts. The blog define the very essence of being an opposition and the articles talks about the â€Å"what should the government do† instead of some other not so important matters. The writers of the said blog discussed point by point their stand regarding all the current issues. While they cited all their grievances, there is also a link where you can comment and side your side. The blog indicates their own perception according to their virtues and they are not persuaded by the current government. They stand on their own, believing that the government should improve and most of all focus on other important issues. The blog is not actually pro-peace because instead of delivering good feedbacks for the government, they criticize and find fault in the current administration. With their writings, they manifested the idea of a conflict between the government and its people. Nonetheless, we are all entitled for our freedom of speech and the liberation to address our concerns. We cannot deny the fact that there are disagreements and probably arguments that is widely expressed by people all over the nation not just in the internet. Now if you’re for pro-peace, you’ll not be able to be persuaded by the ideas and opinions of the blog’s writers but instead you’ll end up switching or finding another blog that tackles about peace and promoting it. On the positive side, the blog just shared their insights and probably their way of solving the problems that they think is more practical. The better thing to do is to also get the side of the government and let them take their part in explaining to the people the real agenda and their plans for the government in improving peace and not war. Works Cited â€Å"U. S. Department of Defense. † 2007. 21 November 2007 http://www. defenselink. mil â€Å"The Peace Alliance Campaign to Establish a U. S. Department of Peace. † 2007. 21 November 2007 http://www. thepeacealliance. org â€Å"The U. S. Peace Government. † 2007. 21 November 2007 http://uspeacegovernment. org â€Å"Daily Kos. † 20 November 2007. 21 November 2007 http://www. dailykos. com.

Research controversy surrounding the constitutionality of using civil Paper

Controversy surrounding the constitutionality of using civil junctions against gangs - Research Paper Example Law enforcement department simply requires to present concrete and enough evidence associating the person to the named gang. The law enforcement agency should provide the identity of people they hang out with, the color of clothes they wear and the tattoos on their body. Due to this, gang injunctions in the US have elicited a heated debate and controversy. Civil rights lobbyists argue that the strategy and the system is not effective and that it violates human rights. They assert that it is unconstitutionally wrong to allow gangs to operate legally. This according to the civil rights movement motivates racial profiling and suppressive policing. Further, they assert that it criminalizes young individuals who may never have done or committed some crimes (O'Deane 48). Wearing wrong colors or a minor mistake or being spotted conversing with a known gang member can be sufficient to get you listed as a gang member. Once an individual is on the list, it is difficult to get a job and difficu lt to escape the area that funnels you into a gang. Law enforcement agents have used injunctions for a long time in fighting gang violence in California. It was first used in Los Angeles in the 1980s; the strategy has proved ineffective in fighting gang violence. ... Supporters of gang injunctions have asserted that the various limitations and threat of penalties act as a deterrent to criminal activities. Nevertheless, in case the reason injunctions are successful has nothing to do with the penalties and limitations that draw the attention of civil rights lawyers. The answer centers on what happens to the gang members when police officers give them evidence they possess of their criminal activities. Traditionally, police officers conceal the information before letting the case to proceed to trial. The law enforcers assume that informing the criminals or gang members about the evidence they have collected against them only assists them defend themselves during trial. However, the success of the gang injunctions is psychological in that by informing the criminals know that they are being monitored, they eventually change and modify their actions and behaviors (Grogger 77). Civil gang injunctions emerged out of extreme anxiety. In the early 190s, th e Los Angeles law enforcers were finding it to control and manage the gangs and these gangs were almost taking control of the city. Assault, homicide, and robbery rates were increasing rapidly. The drug business seemed to be increasing. The gang fights and shooting happened in daylight in public areas. Due to these heinous and criminal activities, gang injunctions were introduced as a strategy for the law enforcement agencies to control the gang activities in the city. Police officers and other law enforcers got a civil court injunction forbidding gang activity in some cities such as Pomona, West Covina, and Santa Ana in Los Angeles. The civil injunctions saw police officers address gang members as a group

Identity Formation and Globalization Essay Example | Topics and Well Written Essays - 3000 words

Identity Formation and Globalization - Essay Example The term "globalisation", in essence, refers to the change of spatial and temporal limitations, which is the reduction of distance because of the remarkable reduction in the time required to bridge spatial differences which has, in turn, caused the slow integration of economic, social and political space across state borders. Even though, globalisation is often solely related to the financial field, which is with processes of distribution, production and consumption along with financial services and growing global trade, financial globalisation is intractably interwoven with changes in the cultural, social and political fields. In addition, globalisation is an extremely multifaceted and complex occurrence. There is, on the one hand, the tendency towards synchronisation, homogeneity, unity, integration and universalism. Also, there is the tendency for localisation, differentiation, heterogeneity, particularism and variety. These procedures are intricately intertwined. They represent, in reality, two sides of the same coin. Hence, the phrase "globalisations" is at times used to show that globalisation is not an ever-present or standardised process, but involves a variety of manifests, terrains differently in diverse contexts. The term – "globalisation" – is used to show that globalisation has different effects for individuals in diverse contexts (Cunningham, 2001). In this rapid globalising planet with all its challenges, struggles for identity have come out as one of the most outstanding traits of the cultural, social and political field.... According to the cultural scientist, this outburst has since 1996 prompted an avalanche. A few other features of modern life have succeeded in drawing the same amount of awareness. "Identity studies" has not only turned into a thriving industry, but the concept of identity has also turned into the prism through which a majority other features of modern life are premeditated. Even traditional issues of social analysis are reformulated and refurbished to fit into the identity dialogue (Cunningham, 2001). Hence, discussions on "equality" and "justice" are discussed in terms of acknowledgment of the right to a separate identity. Culture also is studied in terms of categorical, individual and/or group differences and thoughts such as "hybridity" and "creolisation". In addition, political dialogues often centre on group or individual rights. Talks about identity are, nevertheless, not limited to the ivory towers of academic circles. Also, struggles of identity have become an essential elem ent of intra-individual procedures, as well as of the political, and social scene. As such, struggles and discourses of identity have significant and extensive implications for policymaking on every level. Also, in an endeavor to develop national, local and global people-centered rules, with regard to information and communication technologies, as well as the media, cognizance will have to be taken of these struggles and discourses. Given the importance and prominence of these struggles and discourses and their far-reaching effects, this paper will look at a number of definitions of identity. In addition, it will give attention to the complicated relationship between processes related to globalisation on a variety of levels and struggles for identity. In echoing on identity discourses on

Costing, Budgeting for Projects Accounting Essay

Costing, Budgeting for Projects Accounting - Essay Example 9018088 0.000842049 12 8 13 9 7.703656443 1.680506618 13 9 14 7 7.414185094 0.171549292 14 7 15 4.791208791 44.00883114 -1.008791209 19.92307692 0.247845443 2.110327908 0.57993311 3.738278384 16.56687898 12 231.5175824 167.6967033 Estimating Learning-Curve Functions 2 2) I used the formula approach and forecast approach to estimate non-linear functions such as the learning-curve function. The predicted value for 15 units is 4.791209. Note: When I used the forecast approach, either there was an error in the formula or the predicted value is wrong. The formula on p.209 is =FORECAST(15,B1:B14,A1:A14), but I came up with a predicted value of 4.32967. But since I must arrive at the value 4.791209, I figured the formula should’ve been =FORECAST(15,B2:B15,A2:A15). I finally succeeded at having the same value 4.791209. I think my formula is more accurate because for 14 units of outputs, the DLH value is already given with a value of 7. The formula for regression analysis is Y = a + bX where a is the constant term and b is the slope. When estimating LCR, I used Solver routine in Excel. I started with an estimated LCR of .80 and entered that figure in cell D2. For getting the predicted DLHs, I used Excel learning-curve formula which is =$B$2*A2^(LN($D$2)/LN(2)). For unit 1 (X), the predicted value is an exact match. It is the same as the actual DLH, 29. The rest of the predicted DLHs for outputs 2-14 were a close match except for 9 and 11 units (in thousands) of outputs. Next, I calculated the â€Å"squared-error.† The obvious answer is 0, since there is no error. The predicted DLH is exactly the same as the actual DLH. The formula for â€Å"squared-error† in Excel is =(C2-B2)^2 for 1 unit (in thousands). The rest can be calculated in Solver routine by dragging the cells when copying the formula for 1 unit of output. Estimating Learning-Curve Functions 3 3) Shown on the graph with the downward slope, as the total outputs increased, the cumulative uni ts produced decreased. In other words, the more experience there is in producing outputs, the amount of time to perform the task decreases. The plot is consistent with the data given for units produced and DLHs. 4) I estimated the LCR with the â€Å"incremental unit-time learning-curve model† using Solver routine and I arrived at 0.69 or .70. In the Solver routine window, I entered the â€Å"target cell† as $E$2 which is the â€Å"squared error† contained in E2 and the â€Å"changing cell† as $D$2 which is the Estimating Learning-Curve Functions 4 LCR contained in D2. The exponent in learning-curve model, b, is -0.51681. So for DLH 29, the incremental unit-time learning-curve model is Y = 29.0*X^-0.51681. 5) The formula for cumulative average time per unit to produce x units is Y = ax^b; where Y = cumulative average time per unit to produce x units, a = the time taken for the first unit of output, x = the cumulative number of units, and b = the index of l earning (log LR/log 2). Using the calculation in Excel spreadsheet, I entered the formula =$B$2*A2^(Ln($D2$/Ln(2)) for cumulative av

Forensic Evidence Research Paper Example | Topics and Well Written Essays - 1250 words

Forensic Evidence - Research Paper Example Current technological trends have revolutionized the methods of storing data along with different advanced access mechanisms. These systems facilitate law enforcement agencies by providing instant access to these characteristics. Although, computer forensics also facilitates in investigation of crimes within themselves in order to gather evidence associated with criminal activities that breaches violation of an organizations policy. The data can be extracted from storage devices including hard drives, flash drives, memory cards etc (Computer forensics – a critical need in computer, n.d ) Every online user leaves behind logs related to activities that he or she performs online. This digital traceability can reveal activities that are performed by the user on the Internet by identifying who has identified which files along with logs of each website visited. Temporary files can also reveal flash templates and buffered videos. These traceable logs, files, cookies, templates can fa cilitate a great deal to analyze crimes that are committed from computers and may provide solid evidence against the hacker or cyber-criminal. However, many users trust in files after deleting them from the hard drive but there are many ways and methods via which these files can be recovered. The operating system usually does not delete complete files from the hard drive, even if the user deletes the files from the recycling bin. The files are still present, until they are replaced or overwritten by new files. These traceability factors can lead to aid in forensic investigations and can track down criminals by investigating their computer. For instance, during the execution of a search warrant at the residence of John Robinson who was a serial killer, law enforcement agencies discovered two bodies that were badly decomposed along with seizing of five computers (Computer forensics, n.d ). After investigating computers, it was discovered that the serial killer John Robinson was using internet to find people to schedule a meeting. Afterwards they were killed by sexually assaulting them. These facts were only possible by forensic computing techniques and were not possible by physical evidence and investigation (Computer forensics, n.d ). However, many techniques are associated with forensic computing, few techniques are categorized in to two groups i.e. Graphical User Interface (GUI) based forensic tools and Command line forensic tools (Conklin 2005). The command line tools are relatively small, they can be stored in floppy disks as compared to heavy, and slow GUI based forensic tools. However, command line tools also share some disadvantages in terms of their limitations as they are not capable to identify .zip files and .cab files. GUI based tools provide a graphical user interface and is said to be user friendly because specialized knowledge is not required as compared to command line tools requiring commands on every operation. The disadvantage for GUI based t ools is that they are large and cannot be saved in a floppy disk (Conklin 2005). Similarly, organizations also require a proactive approach for threats that may penetrate within the internal network and extracts or expose sensitive information. There are many ways of forensic data acquisition on a network; we will only consider best practices. Network-Based Evidence Acquisition Practices Network management is effective on many vital management functions. If any one of them is not properly configured, effective network management is not possible. Data acquisition is classified as a vital management process that needs to be addresses proficiently. Likewise, Wireshark will only utilize data that is available