318 research outputs found
Dietary heavy metal exposure of Finnish 1-year-olds
The exposure of Finnish 1-year-olds to cadmium, lead and inorganic arsenic via food and drinking water was determined. The food consumption data consisted of 3-day records from 1010 children aged 12 months, collected during 2002 to 2005 in Southwest Finland. One fifth of these children were still breastfed when the consumption data were collected and their exposure was assessed separately from the non-breastfed children. The heavy metal concentration data in foodstuffs were mainly analysis results from national authorities and they were mostly from the years 2005 to 2012. Dietary exposure assessment was performed probabilistically using the online program MCRA. With middle bound estimates, 89% of the non-breastfed and 56% of the breastfed children exceeded the tolerable weekly intake of cadmium. The benchmark dose (BMDL01) for neurological damage caused by lead was exceeded by 60% of the non-breastfed and by 50% of the breastfed children, while the lowest BMDL01 for cancer risk increase caused by inorganic arsenic was exceeded by 77% of the non-breastfed and by 61% of the breastfed children. The assessment did not include the unknown heavy metal exposure from breast milk. Heavy metal exposure differences between the boys and the girls were also assessed. Breastfed girls had significantly higher heavy metal exposure relative to their bodyweight than the breastfed boys, while in the non-breastfed group there were no differences by sex
Spontaneous symmetry breaking in gauge theories via Bose-Einstein condensation
We propose a mechanism naturally leading to the spontaneous symmetry breaking
in a gauge theory. The Higgs field is assumed to have global and gauged
internal symmetries. We associate a non zero chemical potential to one of the
globally conserved charges commuting with all of the gauge transformations.
This induces a negative mass squared for the Higgs field triggering the
spontaneous symmetry breaking of the global and local symmetries. The mechanism
is general and we test the idea for the electroweak theory in which the Higgs
sector is extended to possess an extra global Abelian symmetry. To this
symmetry we associate a non zero chemical potential. The Bose-Einstein
condensation of the Higgs leads, at tree level, to modified dispersion
relations for the Higgs field while the dispersion relations of the gauge
bosons and fermions remain undisturbed. The latter are modified through higher
order corrections. We have computed some corrections to the vacuum
polarizations of the gauge bosons and fermions. To quantify the corrections to
the gauge boson vacuum polarizations with respect to the Standard Model we
considered the effects on the T parameter. We finally derive the one loop
modified fermion dispersion relations.Comment: RevTeX 4, 13 pages. Added references and corrected typo
Carbon Nanotubes as Nanoelectromechanical Systems
We theoretically study the interplay between electrical and mechanical
properties of suspended, doubly clamped carbon nanotubes in which charging
effects dominate. In this geometry, the capacitance between the nanotube and
the gate(s) depends on the distance between them. This dependence modifies the
usual Coulomb models and we show that it needs to be incorporated to capture
the physics of the problem correctly. We find that the tube position changes in
discrete steps every time an electron tunnels onto it. Edges of Coulomb
diamonds acquire a (small) curvature. We also show that bistability in the tube
position occurs and that tunneling of an electron onto the tube drastically
modifies the quantized eigenmodes of the tube. Experimental verification of
these predictions is possible in suspended tubes of sub-micron length.Comment: 8 pages, 5 eps figures included. Major changes; new material adde
Mikrobilääkeresistenssi ja -jäämät nautatilalla - vaikutukset ympäristöön ja terveyteen (NAMI)
Tässä Ruokaviraston (ennen Elintarviketurvallisuusvirasto Evira), Luken ja SYKEn yhteisprojektissa tutkittiin mikrobilääkejäämien ja resistenttien suolistobakteerien kulkeutumista lääkityistä lypsylehmistä navettaympäristön kautta lantavarastoihin. Lisäksi arvioitiin niiden leviämistä lannan peltolevitysten välityksellä luonnon eliöihin sekä elintarviketuotantoketjussa. Projektissa tutkittiin myös anaerobisen mesofiilisen mädätyksen vaikutuksia lannassa oleviin mikrobilääkejäämiin ja resistentteihin suolistobakteereihin sekä toisaalta lannan mikrobilääkejäämien vaikutusta mädädysprosessin toimintaan. Lisäksi arvioitiin erilaisten lannan prosessointitapojen elinkaarisia ympäristövaikutuksia sekä vaikutuksia mikrobilääkejäämiin ja -resistenssiin.
Resistentit ja moniresistentit suolistobakteerit kulkeutuivat lypsykarjatilalla lantavarastoihin, mutta ne eivät rikastuneet lantaketjussa. Lypsykarjan lietelannasta mitattiin hyvin pieniä pitoisuuksia mikrobilääkkeitä. Lääkittyjen eläinten sonnasta ja virtsasta taas mitattiin hoidon aikana hyvin korkeita pitoisuuksia mikrobilääkejäämiä, jolloin niistä muodostuvissa (kuivissa) lannoissa voi olla korkeita paikallisia pitoisuuksia mikrobilääkkeitä.
Suomessa myös mikrobilääkkeillä lääkittyjen eläinten lannat levitetään pääosin käsittelemättöminä kasvinravinteiksi pelloille, jolloin lannan mukana voi levitä mikrobilääkejäämiä ja resistenttejä suolistobakteereita.
Luonnon eliöt voivat altistua lannassa oleville mikrobilääkkeille ja resistenteille suolistobakteereille myös Suomen olosuhteissa. Lääkittyjen eläinten lantojen lannoitekäyttöä käsittelemättömänä tulisi arvioida kriittisesti.
Mesofiilinen anaerobinen mädätys voi vähentää mikrobilääkejäämiä lannasta, mutta ei välttämättä hajota niitä. Se vähentää elävien suolistobakteerien määrää lannassa, mutta merkittävää vaikutusta resistenttien E. coli -bakteerien osuuteen ei havaittu. Erilaiset lannankäsittelytavat voivat kuitenkin soveltua – ravinteiden kierrätyksen ja energiantuoton lisäksi – mikrobilääkejäämien ja resistenssin torjumiseen, ja niitä tulisikin tässä tarkoituksessa tutkia tarkemmin Suomessa.I detta samprojekt mellan Livsmedelsverket (före detta Livsmedelssäkerhetsverket Evira), Luke och SYKE
undersöktes spridningen av resthalter av antimikrobiella läkemedel och resistenta tarmbakterier från behandlade mjölkkor till gödsellager via ladugårdsmiljön. Därtill uppskattades spridningen till organismer i naturen via gödselspridning på åkrar samt i livsmedelskedjan. I projektet undersöktes även effekten av anaerob mesofil rötning på resthalter av antimikrobiella medel i gödsel och resistenta tarmbakterier samt även effekten av resthalter av antimikrobiella medel på rötningsprocessen. Dessutom analyserades livscykeln för miljöpåverkan av de olika gödselbearbetningsmetoderna samt effekterna på resthalter av antimikrobiella medel och resistens.
Resistenta och multiresistenta tarmbakterier spreds på mjölkgården till gödsellagren, men anrikades inte i gödselkedjan. Mycket små halter av antimikrobiella medel uppmättes i mjölkkornas flytgödsel. Men mycket höga resthalter av antimikrobiella medel uppmättes i gödsel och urin medan djuren behandlades, och då kan det finnas höga lokala halter av antimikrobiella medel i deras (torr)gödsel.
I Finland sprids gödsel även av antibiotikabehandlade djur till största delen obehandlad som växtnäring på åkrar, och då kan resthalter av antimikrobiella medel och resistenta tarmbakterier spridas med gödseln. Organismer i naturen kan utsättas för antimikrobiella medel i gödsel och resistenta tarmbakterier även i finländska förhållanden.
Användningen av obehandlad gödsel från medicinerade djur borde utvärderas kritiskt.
Mesofil anaerob rötning kan minska på mängden resthalter av antimikrobiella medel i gödseln, men bryter inte nödvändigtvis ned dem. Den minskar på mängden levande tarmbakterier i gödseln, men ingen betydande effekt på andelen resistenta E.coli-bakterier påvisades. Olika sätt att behandla gödsel kan ändå, utöver återvinning av näringsämnen och energiproduktion, lämpa sig för bekämpning av antimikrobiella resthalter och resistens, och de borde undersökas mera detaljerat i Finland i det syftet.This study was conducted by Finnish Food Authority (formerly Finnish Food Safety Authority Evira), Natural Resources Institute Finland Luke and Finnish Environment Institute SYKE in 2015–2018. The aims of the study were to examine how antimicrobial residues and antimicrobial-resistant E. coli bacteria spread via the manure chain from the dairy cows treated with antimicrobials to the farm environment and manure storages. Furthermore, the dissemination routes to the surrounding environment, ecosystems and back to the food chain in Finnish conditions were profiled. The effect of mesophilic anaerobic digestion process on the level of antimicrobial residues and antimicrobial-resistant E. coli was examined and, conversely, the effect of antimicrobial residues on the process as well. Finally, the life-cycle of different manure handling and processing methods, and their potential effects on nutrient recycling, energy production, antimicrobial residues and resistant bacteria were evaluated.
Resistant and multi-resistant E. coli spread to the manure storages, although enrichment in their proportion over the manure chain was not detected. Only minor concentrations of antimicrobial residues were measured from the liquid manure. Instead, very high concentrations of antimicrobial residues were measured from the faeces, urine and milk of dairy cows medicated with antimicrobials, which may lead to high local concentrations in (dry) manures composed of them.
In Finland, there is no withdrawal period for manure of medicated animals to be used as a fertilizer. Therefore, manures may contain antimicrobial residues, as well as resistant bacteria, which disseminate to the environment when applied to the fields. Animals and plants may be exposed to antimicrobial residues and resistant bacteria in agricultural and natural ecosystems in Finnish conditions as well. Therefore, fertilizer usage of faeces, urine and milk excreted by animals treated with antimicrobials should be subjected to critical assessment.
Treating the manure with mesophilic anaerobic digestion may reduce the concentration of antimicrobial residues but does not necessarily destroy them. Furthermore, the process reduced the number of total E. coli bacteria, although it did not have an effect on the proportion of resistant E. coli. Along with energy production and nutrient recycling, different manure handling and processing methods may, however, be suitable for destroying and reducing antimicrobial residues and resistant bacteria from manure, and substantially reduce the emission of antimicrobial residues and resistant bacteria to the environment, as well as to the food chain. The aspect of tackling the spread of antimicrobial resistance is
to be considered when manure processing methods are developed in Finland
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV
Isolated photon production is measured in proton-proton and lead-lead
collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the
pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80
GeV with the CMS detector at the LHC. The measured ET spectra are found to be
in good agreement with next-to-leading-order perturbative QCD predictions. The
ratio of PbPb to pp isolated photon ET-differential yields, scaled by the
number of incoherent nucleon-nucleon collisions, is consistent with unity for
all PbPb reaction centralities.Comment: Submitted to Physics Letters
Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
The Lambda(b) differential production cross section and the cross section
ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum
pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7
TeV using data collected by the CMS experiment at the LHC. The measurements are
based on Lambda(b) decays reconstructed in the exclusive final state J/Psi
Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and
Lambda to proton pion, using a data sample corresponding to an integrated
luminosity of 1.9 inverse femtobarns. The product of the cross section times
the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls
faster than that of b mesons. The measured value of the cross section times the
branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06
+/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for
anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are
statistical and systematic, respectively.Comment: Submitted to Physics Letters
Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV
A search is presented for physics beyond the standard model (BSM) in final
states with a pair of opposite-sign isolated leptons accompanied by jets and
missing transverse energy. The search uses LHC data recorded at a
center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to
an integrated luminosity of approximately 5 inverse femtobarns. Two
complementary search strategies are employed. The first probes models with a
specific dilepton production mechanism that leads to a characteristic kinematic
edge in the dilepton mass distribution. The second strategy probes models of
dilepton production with heavy, colored objects that decay to final states
including invisible particles, leading to very large hadronic activity and
missing transverse energy. No evidence for an event yield in excess of the
standard model expectations is found. Upper limits on the BSM contributions to
the signal regions are deduced from the results, which are used to exclude a
region of the parameter space of the constrained minimal supersymmetric
extension of the standard model. Additional information related to detector
efficiencies and response is provided to allow testing specific models of BSM
physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO
Measurement of the mass difference between top quark and antiquark in pp collisions at root s=8 TeV
Peer reviewe
- …