Mass-metallicity relation from z=5 to the present: Evidence for a transition in the mode of galaxy growth at z=2.6 due to the end of sustained primordial gas infall

We analyze the redshift evolution of the mass-metallicity relation in a sample of 110 Damped Ly$\alpha$ absorbers spanning the redshift range $z=0.11-5.06$ and find that the zero-point of the correlation changes significantly with redshift. The evolution is such that the zero-point is constant at the early phases of galaxy growth (i.e. no evolution) but then features a sharp break at $z=2.6\pm 0.2$ with a rapid incline towards lower redshifts such that damped absorbers of identical masses are more metal rich at later times than earlier. The slope of this mass metallicity correlation evolution is $0.35 \pm 0.07$ dex per unit redshift. We compare this result to similar studies of the redshift evolution of emission selected galaxy samples and find a remarkable agreement with the slope of the evolution of galaxies of stellar mass log$(M_{*}/M_\odot) \approx 8.5$. This allows us to form an observational tie between damped absorbers and galaxies seen in emission. We use results from simulations to infer the virial mass of the dark matter halo of a typical DLA galaxy and find a ratio $(M_{vir}/M_{*}) \approx 30$. We compare our results to those of several other studies that have reported strong transition-like events at redshifts around $z=2.5-2.6$ and argue that all those observations can be understood as the consequence of a transition from a situation where galaxies were fed more unprocessed infalling gas than they could easily consume to one where they suddenly become infall starved and turn to mainly processing, or re-processing, of previously acquired gas.Comment: 8 pages, 5 figures, accepted for publication in MNRA

External quality assessment of urinary methylmalonic acid quantification - results of a pilot study

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work noncommercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http:// creativecommons.org/licenses/by-nc/3.0

Population studies on Phytophthora infestans on potatoes and tomatoes in southern Germany

Fifty-seven isolates of Phytophthora infestans from blighted potato foliage were collected in 1995 in southern Germany and analysed for mating type and sensitivity to metalaxyl. Fifty-six of them were characterised as A1 and one as A2 mating types. Resistance to metalaxyl was observed frequently: 53 isolates were resistant, three were partially sensitive, and one was sensitive. In a subsequent field study in 1999, 84 isolates collected from blighted potato and tomato foliage were analysed for mating type. Seventy-two were characterised as A1 and twelve as A2 mating types. The response of 76 isolates to metalaxyl and to propamocarb was tested. The majority (42) of the 76 isolates was classified as resistant to metalaxyl; 31 were partially sensitive and only three isolates were sensitive. The results with propamocarb were less discrete; 10 isolates were classified as resistant and three were clearly sensitive. AFLP fingerprinting was used to examine the genetic structure of the southern German P. infestans population collected in 1999 and indicated that the tested population can be sub-divided into a tomato group, a potato group and a mixed group containing isolates collected from both crops. The presence of Ia and IIa mitochondrial DNA haplotypes indicates that the German P. infestans isolates belong to the new pathogen population that has also been reported in neighbouring regions of Europe. The present study indicates that at the beginning of the season only a few genotypes were present, and the population became genetically more variable at the end of the growing season

A controlled study of the effect of domiciliary tuberculosis chemotherapy programme in a rural community in South India

To study thc ellicttq of a domiciliary drug-therapy programme in the control of tuberculosis in a rural community, an investigation was set lip in 1958 under the auspices of the Indian Council of Medlenl I{C!IClln:h ill 12 towns with populations ranging from 6000 to 25000, all within 160 km of Madanapallc (Andhra Pradt'Sh). The prevalences of bacillary and radioloj.(ic~ll cases of pulmonary tuberculosis in adults (llgcd 15 )T or more) were estimated in .. ch town by carrying out a hase-Iine random sample survey iu 1959; also, the prevalences of tuberculous infcl'tion in all schoolchildrt,n aged 5 to 9yr wen' estimated. These thn.'t' in.dices of prevalence were used to rank the 12 towns and tben ndomlyallocate them into two l'omparable groups of 6 towns each, designated as 'Ireatment' and '~:ontmJ' tOWIlS. In treatment tOWIIS, intensi"e case finding ,,-as undertaken hy means of 2 X-ray surveys (suney I during 1960-61 and survey II during 1962-64) l'ovcring alllldults, sputum examinations by microSl'op' Hnd culture when indicated, and eriodic follow lip of all 'suspect' cases with X-ray and SPlltuDl examinations. All bacillary cases were offered domiciliary treatment for onc ~'ear with isoniazid and PAS in the J treatment IOWll~ (selected at random) a.nd with isoniazid alone in the other 3 town.·,. Of 148 2easc~ eligible for trcat-at ment in tJlC 6 treatment towns, 15 per l'en.t refused treatment nd 29 per cent discontin.ued chemotherapy prematurely. In lhe rontrol towns, 0.0 spcdal faeililies for di~gn()sis 01' calment ,vere introduced, and patients w~'re left to the routine treatment facilities aV:lilahk' locally. A tuberculosis prcntlcm:e survey (~ul'l'ey Ill) t'O\'cri~ all adults was 1.1lrried out iD 9.1112 towns during 1965-68, am! lhi:; ~:l." followed hy a random tuberculin sample survey during 1966-69. The overall results of treatment at the end of one year ,,'eJ'e.' (i) among cases initially positive hy micro~opy, 10 per' nt died, 33 per locnt rcmllincd sputum-positive IUld 51 per cent became sputum-negative in INH-PAS towns, the mrl'lsponding percentages fur INH lowns being 15, 48 and 37 per cent respectivel~'; (ii): moug cases initially positive by culture ()nJy, 6 per ent died, 26 J1er cent remained sputum-posithc and 68 per cent became sputum negative in lNH-PAS towns, tbe correspondi percentages for tile INH town~ being 1, 38 an. 55 IJer cent respectively. All the bacillary cases (treated or untrcatt'lf) were followed up and their status at the end of 5 yr was 40.4 per cent dead, 18.2 per cent sputum-positive and 41.4 pCT cent sputum-ne'~ative. Spntum status at one year had considerable prognostic value. Of 532 sputum-negative ea .. at one year, 18 per l'ent were dead, 16 per CCDt sputuDl-posithe and 66 per cent sputum-ncgath'e 5 yr aftenvards, where'd!! the corresponding percentagt'S for (JIC 319 sputum-positive cases at one year were 56, 20 llnd 24 respectively. There was an intennl of about 2l ~'r between sunc)' [ and survey [[ and ahout 4 yr between survey [J and survey 111 in the 6 treatmellt towns. The prevalence of badllary cases in these sUr\'eys was age-standardised, cousidering separately l'UseS found hy microscopy and cases found by culture only. The lJlean prevalence of cases (Wsitive hy microscopy in the 6 treatment towns was 6.81 per thousand in survey I and it decre~sed significanUy (P < 0,01) to 5.01 in survey nand 4.83 in survey Ill. Change of culture technique during the course of the investi~ation complicated the interpretation of prcva· lenl'C:l of culture-positive cases. BetwCCR the 1959 base-line survey and tbe resurvey in 1965·68, the prevalence ()f smear-positive tuberculosis decreas~d from 5.92 per thousand adults to 4.78 in the 6 treatment towns, and similarly from 5.72 to 4.21 in the 6 control towns. The prcvalenl-e of 'culture only-positive' cases was 3.85 and 2.44 per thousand adults in the treatment and control towns respectively at the base-line survey and (with the more sesnsitive culture technique) 4.92 and 4.82 per thousand adults at the resurvey in 1965·68. Lastly, tho tuberculin survey in 1966·69 did not I" .,'ell! any' significant differences between the tr t· ment and the control towns. The inability ofthe domiciliary treatment programme to make an impact on the prevalefl:lc of tuberculosis in the rural community around Madanapalle is a finding that has cOllsidera lie siJ,(nilicance in the context of the tubercUlosis control programme in fndia; the rl'asons for the failure aud its implications are discussed

DGNB building certification companion: Sustainability Tool for Assessment, Planning, Learning, and Engaging (STAPLE)

In the construction industry, the popularity of sustainability and its benefits have been on the rise in recent years. Alas, with various building sustainability assessment schemes on the market, there is still no single general method for a comprehensive and inclusive design and building process for sustainable buildings. The literature describes several barriers of entry preventing actors in the industry from seeking sustainability certifications and prioritizing design methods, supporting sustainability in greater numbers. In the newly developed tool, “DGNB building certification companion: Sustainable Tool for Assessment, Planning, Learning, and Engaging (STAPLE)”, a new Excel-based, interactive, and iterative education focused platform is introduced, intended to engage dialog among stakeholders, building owners, and decision makers, and the assigned group team leaders, based on the five DGNB topics. In order to establish common levels of knowledge, terminology, and understanding for proper interdisciplinary discussions, which would result in suitable and timely decisions, personal and professional development is enabled by imbedded educational documents in multiple formats throughout the tool as plain-language, easily digestible summaries of various topics regarding sustainability and the DGNB certification scheme. The identified barriers are described in the tool followed by a solution to overcome them. The tool, tested at multiple stages of development and moulded by many individuals both within and outside of the sustainable building industry, has shown to achieve the primary goals of assessment of individual’s current knowledge, educating through multiple stages and formats, and the inspiring of conversation among team members through a graphical display of opinions. Based on user feedback, the conclusion was that this is a desired product on the market. This new approach is expected to dramatically reduce misunderstandings, conflicts, and mistakes during a sustainable design process, helping the design team plan a project to possibly obtain the highest DGNB score if desired and properly documented

The Sightline to Q2343-BX415: Clues to Galaxy Formation in a Quasar Environment

(Abridged) We have discovered a strong DLA coincident in redshift with the faint QSO Q2343-BX415 (R = 20.2, z_em = 2.57393). Follow-up observations at intermediate spectral resolution reveal that the metal lines associated with this 'proximate' DLA consist of two sets of absorption components. One set is moving towards the quasar with velocities of ~ 150-600 km/s; this gas is highly ionized and does not fully cover the continuum source, suggesting that it is physically close to the active nucleus. The other, which accounts for most of the neutral gas, is blueshifted relative to the QSO, with the strongest component at ~ -160 km/s. We consider the possibility that the PDLA arises in the outflowing interstellar medium of the host galaxy of Q2343-BX415, an interpretation supported by strong C IV and N V absorption at nearby velocities, and by the intense radiation field longward of the Lyman limit implied by the high C II*/H I ratio. If Q2343-BX415 is the main source of these UV photons, then the PDLA is located at either ~ 8 or ~ 37 kpc from the active nucleus. Alternatively, the absorber may be a foreground star-forming galaxy unrelated to the quasar and coincidentally at the same redshift, but our deep imaging and follow-up spectroscopy of the field of Q2343-BX415 has not yet produced a likely candidate. We measure the abundances of 14 elements in the PDLA, finding an overall metallicity of ~ 1/5 solar and a normal pattern of relative element abundances for this metallicity. Thus, in this PDLA there is no evidence for the super-solar metallicities that have been claimed for some proximate, high ionization, systems.Comment: Accepted for publication in the Astrophysical Journal. 27 pages, 8 tables, 21 postscript figure

Optical/near-infrared selection of red QSOs: Evidence for steep extinction curves towards galactic centers?

We present the results of a search for red QSOs using a selection based on optical imaging from SDSS and near-infrared imaging from UKIDSS. For a sample of 58 candidates 46 (79%) are confirmed to be QSOs. The QSOs are predominantly dust-reddened except a handul at redshifts z>3.5. The dust is most likely located in the QSO host galaxies. 4 (7%) of the candidates turned out to be late-type stars, and another 4 (7%) are compact galaxies. The remaining 4 objects we could not identify. In terms of their optical spectra the QSOs are similar to the QSOs selected in the FIRST-2MASS red Quasar survey except they are on average fainter, more distant and only two are detected in the FIRST survey. We estimate the amount of extinction using the SDSS QSO template reddened by SMC-like dust. It is possible to get a good match to the observed (restframe ultraviolet) spectra, but for nearly all the reddened QSOs it is not possible to match the near-IR photometry from UKIDSS. The likely reasons are that the SDSS QSO template is too red at optical wavelengths due to contaminating host galaxy light and that the assumed SMC extinction curve is too shallow. Our survey has demonstrated that selection of QSOs based on near-IR photometry is an efficent way to select QSOs, including reddened QSOs, with only small contamination from late-type stars and compact galaxies. This will be useful with ongoing and future wide-field near-IR surveys such as the VISTA and EUCLID surveys. [Abridged]Comment: 74 pages, 6 figures. Accepted for for publication in ApJ

Three-loop matching coefficients for hot QCD: Reduction and gauge independence

We perform an integral reduction for the 3-loop effective gauge coupling and screening mass of QCD at high temperatures, defined as matching coefficients appearing in the dimensionally reduced effective field theory (EQCD). Expressing both parameters in terms of a set master (sum-) integrals, we show explicit gauge parameter independence. The lack of suitable methods for solving the comparatively large number of master integrals forbids the complete evaluation at the moment. Taking one generic class of masters as an example, we highlight the calculational techniques involved. The full result would allow to improve on one of the classic probes for the convergence of the weak-coupling expansion at high temperatures, namely the comparison of full and effective theory determinations of the spatial string tension. Furthermore, the full result would also allow to determine one new contribution of order O(g**7) to the pressure of hot QCD.Comment: 19 pages, 2 figures. v2: new Section 6 discussing applications, to match journal versio