johvdvutqrpvcaaasalertsorg science online week science alert 319 5864 current issue previous issue science express science products science journal week science volume 319 issue 5864 cities dated february 8 2008 available httpwwwsciencemagorgcontentvol319issue5864twisdtl copy week science section appended week science february 8 2008 319 5864 week science quantum phase via geometry phase wave function collapses measurements made additional information needed determine phase several methods developed based interference reference waves moon et al p 782 describe noninterferometric approach phasedetermination based isospectrality describes pairs simple polygonal shapes frequency responsethat shapes drumheads could sound indistinguishable authors used scanning tunneling microscopy position co molecules cu111 surface cryogenic temperatures bound isospectral shapes despite imperfect nature boundary spectral fingerprints twodimensional electronic states terahertz range within experimental error authors used property extract wave function phase phase extraction possible twodimensional quantum systems provided boundary shapes constructed credit hari manoharanstanford university spin hall effect light hall effects manifest transverse movements carriers electronic current presence external field recent work concentrated spin hall effect effects depend spin electron charge hosten kwiat p 787 published online 10 january see perspective resch report observation optical version spin hall effect developed sensitive metrological technique capable detecting displacements angstrom scale light refracts airglass interface additional displacement light depends polarization optical system polarization light interacts refractive index gradient manner analogous electronic spins affected electric fields moving heat materials positive coefficient thermal expansionthey expand heatedbut exceptions cubic zirconium tungstate contract wide temperature range silveri hexacyanocobaltate iii framework material highly underconstrained cocnagncco linkages goodwin et al p 794 find wide temperature range material either contract expand along orthogonal lattice directions coefficient order magnitude greater materials attribute large movements framework flexing like hinged lattice sort commonly seen garden fencing credit goodwin et al every step take walk expend energy pushing planted leg also leg decelerates makes contact ground donelan et al p 807 developed mechanical device harvest expended energy deceleration step much fashion hybrid automobiles utilize regenerative braking device light fastens knee produces 5 watts power potentially enough power charge portable medical devices bonds shaken sliced soon development narrowfrequency laser sources chemists attempted use sources excite specific chemical bonds unfortunately deposited energy usually spread around rest molecular framework rapidly chosen bond break recently studies shown collisions molecules catalytic surfaces occur soon enough vibrational excitation reaction efficiencies selectively enhanced killelea et al p 790 see perspective mullins sitz take approach step show exciting ch stretch chd3 isotopomer methane prior collision nickel surface achieve 301 ratio ch cd bond cleavage relative 13 ratio thermally equilibrated sample quantification selective scission required technically demanding massresolved detection scheme thermally desorbed products sounding earths core earths solid inner core predominantly phase iron high pressures one important clue determining properties core sound waves passing earths solid inner core propagate fastest along northsouth direction suggests preferred alignment iron crystals belonoshko et al p 797 present numerical calculations show bodycentered cubic form iron strongly anisotropic seismic waves match observed 12 anisotropy whereas hexagonal closepacked form previously thought make inner core mixedup microflora relationship animal host complex mixture microbes carries gut delicate one exact role host immune system plays maintaining commensal homeostasis remains unclear ryu et al p 777 see perspective silverman paquette published online 24 january examined expression antimicrobial proteins gut fruit fly drosophila melanogaster although key immune transcriptional regulator nuclear factor kappa b nfb chronically activated flies indigenous gut microflora subset nfbregulated antimicrobial genes actually expressed transcriptional repression exerted intestinal homeobox gene caudal disruption caudal expression resulted expression different subset antimicrobial peptides well dramatic change composition intestinal microflora led apoptosis intestinal epithelial cells loss host viability tangled food web weave direct indirect effects mediate bottomup influences diversity complexity food web bukovinszky et al p 804 compared effects two related plants domestic brussels sprouts feral brassica aphid herbivores aphids parasitoid wasps wasps secondary parasitoids examine resource quality affects food web structure complexity multilevel trophic system differences resource base cascaded system via array direct indirect effects led substantial differences structure complexity resulting food webs growing role centrosomes genetic analyses individuals extreme forms short stature provide insights biological mechanisms regulating human growth rauch et al p 816 published online 3 january see perspective delaval doxsey identified mutant gene responsible microcephalic osteodysplastic primordial dwarfism type ii mopd ii adults rare inherited condition reach average height 100 centimeters although brain comparable size threemonthold baby nearnormal intelligence culprit gene pcnt encodes pericentrin centrosomal protein implicated mitotic spindle anchoring chromosome separation cell division although precise mechanisms cellular phenotype produces size phenotype remains determined intriguing inherited forms microcephaly disorders characterized small brain size likewise genetically linked centrosomal mitotic spindle genes credit rauch et al tipping balance cell decisions thymus key developmental decisions made farreaching consequences immune system perhaps notable commitment thymocytes becoming cd4 helper cd8 cytotoxic cells transcriptional factor thpok commits thymocytes still express cd4 cd8 coreceptors becoming cd4 cells alternate developmental option generated setoguchi et al p 822 find cells would otherwise destined become cd8 cells redirected cd4 lineage loss members another transcription factor family runx seems normal circumstances runx complex represses thpok expression allows cd8 cells emerge heme balancing act heme component several hemoproteins required aerobic cells oxygen transport storage hemoglobin myoglobin electron transfer drug metabolism cytochromes signal transduction nitric oxide synthases however free heme toxic intracellular concentration must carefully regulated keel et al p 825 generated mice lacking heme export protein flvcr feline leukemia virus subgroup c receptor show factor required terminal red blood cell development suggest heme toxicity may common pathophysiology erythroid disorders freehemebalance perturbed additionally flvcr functions recycling hemeiron senescent red cells hemeiron trafficking via flvcr involved systemic iron homeostasis uneven heat gain recent global warming uniform across regions order predict accurately impacts warming spatial pattern temperature change needs understood lozier et al p 800 published online 3 january examined north atlantic gained heat past 50 years total amount heat gained within basin approximately would expected tropics subtropics warmed subpolar ocean cooled results interpreted help ocean general circulation model mostly result wind buoyancy forcing associated north atlantic oscillation although spatial pattern temperature change north atlantic directly reflect global warming may indirect result warming transmitted largescale changes atmospheric circulation nanoscale 3d imaging superresolution fluorescence microscopy methods capable breaking diffraction limit resolution conventional light microscopy 200 300 nanometers nm techniques improved twodimensional 2d image resolution achieving 3d nanoscale resolution remained challenge huang et al p 810 published online 3 january used optical astigmatism method develop 3d stochastic optical reconstruction microscopy storm examined intracellular clathrincoated pits microtubules image resolution 20 30 nm lateral dimensions 50 60 nm axial dimension fixed cells specifying gene expression efficiency gene transcription rna polymerase ii modulated composition promoter chromatin including presence nucleosomebinding proteins using genomic approach krishnakumar et al p 819 show polyadpribose polymerase1 parp1 linker histone h1 two nucleosomebinding proteins compete binding nucleosomes vitro exhibit reciprocal pattern binding many promoters vivo positively regulated promoters parp1 bound h1 thus promoter localization patterns nucleosomebinding factors specify global gene expression outcomes vivo relatedness reproductive success appears marrying cousin may bad idea provided sufficient distance degree relatedness helgason et al p 813 analyzed recorded genealogies 10 generations icelanders test effect relatedness reproductive success marriages third fourth cousins produced children grandchildren marriages highly related less related people icelandic society urbanized past 200 years rural populations moving urban areas relatedness married couples diminished accompanied drop reproductive success unsubscribe edit subscriptions service httpwwwsciencemagorgcgialertsmain written requests unsubscribe may sent customer service 1454 page mill road palo alto ca 94304 usa magazine news signaling careers multimedia collections help site map rss subscribe feedback privacy legal us advertise us contact us 2008 american association advancement science rights reservedaaas partner hinari agora patientinform crossref counter tue 05 aug 2008 123604 0800 science citetrack week science