bluuebunny/crossref_metadata_2025 huggingface dataset:
Þátttaka í sjálfboðastarfi á Íslandi
Authors: Hrafnsdóttir Steinunn , Jónsdóttir Guðbjörg Andrea , Kristmundsson Ómar H.
Published: January 2015

Í greininni er fjallað um þátttöku Íslendinga í sjálfboðastarfi. Rannsóknin sem byggir á gagnasafni Evrópsku lífsgildakönnunarinnar (EVS) frá 1990-2010 er sett í samhengi við alþjóðlega fræðilega umræðu um sjálfboðaliða og þátttöku í sjálfboðastörfum. Um þriðjungur Íslendinga 18 ára og eldri tók þátt í sjálfboðastörfum 2009-2010, örlítið færri en 1990, 75% voru í félögum og er það svipað hlutfall og 1990. Flestir vinna fyrir íþrótta- og tómstundafélög og félagsaðild í þeim er einnig mest. Því næst koma velferðarfélög en hlutfallslega mest hefur dregið úr sjálfboðastörfum á sviði velferðarmála. Karlar eru mun líklegri en konur til að sinna sjálfboðastörfum hjá íþrótta-og æskulýðsfélögum en í öðrum sjálfboðastörfum er ekki munur á kynjum. Algengara er að fólk eldra en 50 ára sinni sjálfboðastörfum en yngra fólk, sérstaklega fyrir velferðarfélög. Háskólamenntaðir eru líklegastir til að sinna sjálfboðastörfum. Staða á vinnumarkaði hefur áhrif hvort fólk vinnur sjálfboðastörf, sérstaklega meðal íþrótta-og æskulýðsfélaga. Gift fólk er í öllum tilvikum líklegra en aðrir hópar til að stunda sjálfboðastörf og þeir sem búa í dreifbýli eru einnig líklegri en þeir sem búa í þéttbýli til að sinna slíkum störfum. Niðurstöðurnar eru að meginstefnu sambærilegar niðurstöðum erlendra rannsókna og veita mikilvægar upplýsingar um þátttöku í sjálfboðastarfi á Íslandi og þróun hennar í alþjóðlegu samhengi.
Umhverfisleg sjálfbærni Íslands: Staðan og aðkoma stjórnvalda
Authors: Jóhannsdóttir Lára , Davíðsdóttir Brynhildur , Ólafsson Snjólfur
Published: January 2015

Umhverfisleg sjálfbærni miðar að því að ekki sé gengið á höfuðstól náttúrunnar þannig að komandi kynslóðir beri skarðan hlut frá borði þegar kemur að því að hagnýta náttúrugæði. Tilgangur með rannsókn þessari var að fá sýn sérfræðinga á umhverfislega sjálfbærni Íslands, styrkleika, veikleika og möguleika til úrbóta. Gagna var aflað með rýnihópaviðtölum við sérfræðinga á sviði líffræðilegs fjölbreytileika, orku, vatns, landnýtingar, úrgangsmála, hafs og stranda, og lofthjúps, auk þess að meistaranemar tóku þátt í rýnihópaviðtali. Niðurstaðan leiddi í ljós að þrátt fyrir að sérfræðingahópunum hafi verið ætlað að fjalla um umhverfislega sjálfbærni út frá ólíkum umhverfislegum þemum þá komu fram svipaðar áherslur innan hópanna hvað stjórnsýsluleg atriði varðar. Áherslurnar voru á stefnumörkun stjórnvalda, mælingar og eftirlit, lög og reglur, hagræn stjórntæki, stjórnsýslu, pólitík, skipulagsmál, hagsmunaaðila, rannsóknir og samvinnu. Umræðan í rýnihópunum snérist í meira mæli um veikleika og hvar úrbóta er þörf, fremur en um styrkleika. Því má álykta sem svo að það sé verk að vinna þegar kemur að stjórnsýslulegum þáttum sem snúa að umhverfislegri sjálfbærni Íslands.
Leyfi til raforkuframleiðslu – Skyldur ríkja samkvæmt raforkutilskipuninni í ljósi reglna um jafnræði og gagnsæi
Authors: Haraldsdóttir Kristín
Published: January 2015

Í greininni er fjallað um það fyrirkomulag leyfa til raforkuframleiðslu, sem mælt er fyrir um í 7. gr. tilskipunar 2009/72/EB um innri markað raforku. Fyrirkomulagið á að stuðla að greiðum aðgangi að framleiðslu raforku og virkri samkeppni. Leitað er svara við því hvaða skyldur ríkin verða að uppfylla samkvæmt reglum 7. gr., einkum í ljósi krafna um jafnræði og gagnsæi í málsmeðferðinni, og jafnframt hvort reglurnar þjóni tilgangi sínum. Færð eru rök fyrir því að óljóst sé hvaða skyldur reglurnar leggi á ríkin. Þær taki ekki nægilega vel mið af því hve málsmeðferð vegna leyfa til að reisa og reka raforkuver er ólík og flókin í aðildarríkjunum og því hve raforkuver eru ólík að stærð og gerð.
Iceland’s External Affairs from 1550-1815: Danish societal and political cover concurrent with a highly costly economic policy
Authors: Þórhallsson Baldur , Joensen Tómas
Published: January 2015

The paper argues that there is not necessarily a correlation between political, economic and societal shelter. Iceland received considerable societal and political shelter from Denmark in the period under study, but Denmark failed to provide its remote island with economic cover. Firstly, and most importantly, it provided substantial and highly valuable societal shelter. Copenhagen was the main channel by which new knowledge and technology could enter Iceland. The islanders benefited from educational, health-care and social policies of the crown and it played an invaluable role in preserving Iceland’s cultural heritage. Secondly, Denmark provided partial protection of Icelandic waters and land though Iceland’s peripheral position continued to be its main protection from outside attacks. However, at the end of our period, the Danish kingdom was in decline and unable to provide political cover. Nevertheless, increased centralization, initiated from Denmark, provided internal order and political stability and citizens became more equal before the law. Thirdly, Icelanders paid a heavy price for the Danish trade monopoly though Icelanders continued to receive partial economic and societal shelter from foreign merchants and fishermen. The crown’s policies towards Iceland can largely be explained by current ideological trends at any given time. By being in constant contact with the European continent through Denmark, Icelandic society was part of the societal, political and economic evolution in Europe and managed to avoid isolation despite its geographical remoteness.
Sætaskipun á Alþingi
Authors: Magnússon Þorsteinn
Published: January 2015

Tæp hundrað ár eru liðin síðan samþykkt var á Alþingi að þingmönnum skyldi skipað til sætis með drætti við upphaf hvers þings. Sú skipan þekkist ekki nú meðal annarra þjóðþinga. Ekki hefur legið fyrir hvers vegna sætadráttur var innleiddur á Alþingi, hvernig framkvæmd hans hefur verið, hver hafa verið viðhorf þingmanna til sætadráttar eða hvort þetta fyrirkomulag hafi haft einhver áhrif á samskipti þingmanna og starfsemi Alþingis. Í þessari grein eru birtar niðurstöður fyrstu rannsóknar á þessu efni hérlendis. Jafnframt er sætaskipun Alþingis sett í alþjóðlegt samhengi, en meginreglan um heim allan er að þingmenn sitja saman í flokkahópum. Niðurstöður rannsóknarinnar eru m.a. þær að mestar líkur eru á því að fyrirmyndin að sætadrætti sé sótt til fulltrúadeildar Bandaríkjaþings, en þar tíðkaðist sætadráttur á árunum 1845- 1913. Þá leiðir rannsóknin í ljós að það liðu rúmlega 40 ár þar til sætadráttur festist að fullu í sessi á Alþingi. Í efri deild var á flestum þingum fram til 1959 fallið frá sætadrætti og virðast þingmenn þá einkum hafa setið eftir flokkum. Í neðri deild var algengt að ýmsir þingmenn skiptu á sætum að loknum sætadrætti og þar var líka um tíma uppi viðleitni til að koma á sætaskipun eftir flokkun en hún fékk ekki hljómgrunn. Síðan 1959 hefur ekki verið neinn ágreiningur um sætadrátt. Almennt virðast alþingismenn þeirrar skoðunar að sætaskipun Alþingis hafi jákvæð áhrif á samskipti þingmanna, sé jákvætt mótvægi við skiptingu þingheims í stjórnarliða og stjórnarandstæðinga og auk þess sé sætadráttur sanngjörn leið til að skipa mönnum til sætis. Reynslan af sætadrætti á Alþingi er því vísbending um að það geti skipt máli fyrir þingmenn hvernig sætaskipun er háttað.
Samanburður á ráðningarferli við embættisveitingar á Íslandi fyrir og eftir efnahagshrunið
Authors: Aðalsteinsson Gylfi Dalmann , Möller Berglind
Published: January 2015

Í þessari rannsókn er farið yfir ráðningarferli í skipun embætta hjá hinu opinbera á tímabilinu 2004 til 2012 og kannað hvort ráðningarferlið að undangenginni veitingu embættis hafi breyst eftir efnahagshrunið haustið 2008. Um er að ræða 68 embættisveitingar, 40 fyrir efnahagshrun og 28 eftir hrun, sem uppfylltu skilyrði 13. töluliðar 22. gr. starfsmannalaga og töldust vera embætti. Við úrvinnslu og greiningu gagna var notuð innihaldsgreining sem er blanda af eigindlegri og megindlegri rannsóknaraðferð. Greint var hvort auglýsingarnar uppfylltu skilyrði um auglýsingar eins og þau birtast í reglum nr. 464/1996 um auglýsingar á lausum störfum, hvort auglýsingar um laus embætti birtust í Lögbirtingablaðinu, hvort umsóknarfrestur væri í samræmi við 7. gr. starfsmannalaga, hvort stuðst hafi verið við hæfnisnefndir og loks hversu langt ráðningarferlið var. Niðurstöður þessarar rannsóknar gefa til kynna að breytingar hafi orðið til batnaðar á ráðningarferlinu eftir efnahagshrunið, einkum hvað varðar starfsauglýsingar, útfærslu þeirra og birtingu, rétt tilgreindan umsóknarfrest, hæfnisnefndir oftar notaðar á kostnað ráðningar- og ráðgjafafyrirtækja. Hins vegar hefur ráðningarferlið lengst eftir efnahagshrunið.
Vilji, völd og veruleiki í opinberri stefnumótun á Íslandi. Af óförum Íbúðalánasjóðs 2003-2005
Authors: Sigurgeirsdóttir Sigurbjörg
Published: January 2015

Þessi rannsókn beinist að samspili stjórnmála, stjórnsýslu og markaðar á Íslandi. Markmið hennar er að varpa fræðilegu ljósi á það hvernig stjórnmál og stjórnsýsla virka þegar stjórnvöld taka ákvarðanir og framfylgja þeim í umhverfi þar sem ákvarðanir og áhrif þeirra eru á mörkum valdsviðs hins opinbera og markaðarins. Ákvörðun um hækkun í 90% lánshlutfall Íbúðalánasjóðs er tilvikathugun sem skoðuð er í ljósi dagskrárkenninga í opinberri stefnumótun. Rannsóknin byggir á gögnum úr Rannsóknarskýrslum Alþingis um orsakir og fall íslensku bankanna og Íbúðalánasjóð, og á upplýsingum úr viðtölum höfundar innanlands og utan. Rannsóknin sýnir að þegar ákvörðunin var tekin var blásið til samkeppni við og milli einkavæddra banka. Tilraunir sjálfstæðismanna í ríkisstjórn til að hafa áhrif á niðurstöðuna með því að hnika til ákvörðun framsóknarmanna fólu í sér kerfisbreytingu studdar stjórntæki til að verja sjóðinn áhlaupi. Áhrif stjórntækisins, þ.e. uppgreiðslugjalds, samrýmdist ekki flokkspólitískum hagsmunum framsóknarmanna. Í kapphlaupi um að koma kosningaloforði sínu að komu framsóknarmenn sér hjá því að taka mið af gjörbreyttum fjármálamarkaði sem sjóðurinn var orðinn hluti af. Niðurstöður rannsóknarinnar benda til þess að þeir sem horfa til lengri tíma í pólitík marki opinbera stefnu með breytingum á gangverki kerfa og láti stefnuna gerast sjálfkrafa. Þeir sem horfa til skemmri tíma breyti einstaka verkefnum. Aftur á móti raska kerfislægar breytingar dreifingu valds og áhrifa og setja frekari tilraunum stjórnvalda til breytinga á kerfinu skorður, nema því aðeins að saman fari eindregin pólitískur vilji og samstaða stjórnvalda samfleytt yfir nægilega langan tíma til að vilji stjórnvalda gangi eftir.
Facebook og flokkarnir: Rannsókn á notkun íslenskra stjórnmálaflokka á samfélagsmiðlum
Authors: Bergsson Baldvin Þór
Published: January 2015

Vægi samfélagsmiðla í þjóðmálaumræðunni eykst stöðugt en lítið er vitað um raunveruleg áhrif þeirra á pólitískan áhuga og þátttöku. Í þessari grein er skoðað hvað einkenndi notkun íslenskra stjórnmálaflokka á þessum miðlum fyrir alþingiskosningarnar 2013 og hvort merkja megi áhrif kjósenda á flokkana í gegnum samfélagsmiðla. Einnig eru skoðuð gögn úr Íslensku kosningarannsókninni um tengsl pólitísks áhuga og netnotkunar. Stuðst er við erlendar rannsóknir á samfélagsmiðlum og farið yfir helstu kenningar fræðimanna um eðli þeirra og möguleg áhrif. Umræða um samfélagsmiðla virðist oft einkennast af rómantískum hugmyndum, en endurspeglar ekki endilega raunveruleikann eins og hann birtist okkur í rannsóknum. Niðurstaða greinarinnar er að notkun íslensku flokkanna einkenndist af einhliða samskiptum en ekki samræðum við kjósendur. Facebook er mikilvægasti samfélagsmiðillinn og nýtist best til auglýsinga og til að dreifa skilaboðum á einfaldan hátt til hóps kjósenda. Fátt bendir til að almenningur hafi haft mikil áhrif á kosningabaráttuna í gegnum þessa miðla, eða að þeir hafi haft veruleg áhrif á niðurstöðu kosninganna. Þá virðist fólk með mikinn pólitískan áhuga vera líklegra til að nýta sér netið til að fá upplýsingar frá framboðum.
Siðfár í íslensku samfélagi? Koma e-töflunnar til Íslands
Authors: Jónasson Jónas Orri , Gunnlaugsson Helgi
Published: January 2015

Neysla ólöglegra vímuefna hefur sýnt sig að vera einkar vel fallin til að skapa ótta og óöryggi í samfélaginu. Þegar ný efni koma fram á sjónarsviðið eykst oft umfjöllun fjölmiðla um notkun efnisins og þá hættu sem af neyslunni stafar. Skömmu eftir að e-taflan barst til landsins á tíunda áratug síðustu aldar fór neyslan að valda miklum usla og öryggisleysi hér á landi. Hér verður kenningunni um siðfár beitt til að kanna hvort koma e-töflunnar til landsins beri merki siðfárs. Greint verður frá umfjöllun fjölmiðla, viðbrögðum almennings, fagstétta og stjórnvalda við komu efnisins hingað til lands. Stuðst er við orðræðugreiningu á öllum fréttum um e-töfluna, sem birtust á tímabilinu 1985- 1997, til að meta hvort siðfár hafi skapast í íslensku samfélagi. Niðurstöðurnar benda til að viðbrögð hér á landi hafi sýnt ýmis merki siðfárs eins og lýst er í þekktum kenningum um fyrirbærið.
Post-harvest height growth of Norway spruce seedlings in northern Finland peatland forest canopy gaps and comparison to partial and complete canopy removals and plantations
Authors: Hökkä Hannu , Mäkelä Hanna
Published: January 2015

Recent studies have shown the establishment of Norway spruce (Â (L.) Karst.) to be successful in small canopy gaps cut in drained spruce mire stands in northern Finland. The aim of this study was to quantify seedling height growth in gaps and compare it to that observed in other canopy cuttings and plantations. We sampled spruce crop seedlings (maximum density ca. 3000 ha) in the spring of 2013 in a field experiment in which canopy gaps of 10, 15 and 20 m in diameter had been cut in winter 2004. The total seedling height in 2013 and the length of annual shoots over the past five years (2012â2008) were recorded in the survey. Seedling height varied from 20 cm to 2.7 m, with an average of 65 cm. The average annual height growth was 7.1 cm. A mixed linear model analysis was carried out to investigate seedling height growth variation. Seedling height was linearly and positively related to growth. Height growth started to increase in the fifth growing season after cutting. Seedling height growth in the 20 m gap was slightly better than in the smaller ones. In the 15 m gap, both the centrally located seedlings and those located at the northern edge grew best. In the 20 m gap, southerly located seedlings grew more slowly than seedlings in all other locations. The average seedling height growth in this study was about 60% of that in peatland plantations, but comparable to that in mineral soil gaps, and 2â3 times higher than in uneven-age cut stands.Picea abiesâ1
Risk, Information, and Incentives in Online Affiliate Marketing
Authors: Edelman Benjamin , Brandi Wesley
Published: January 2015

The authors examine online affiliate marketing programs in which merchants oversee thousands of affiliates they have never met. Some merchants hire outside specialists to set and enforce policies for affiliates, whereas other merchants ask their marketing staff to perform these functions. For clear violations of applicable rules, the authors find that outside specialists are the most effective at excluding the responsible affiliates, which can be interpreted as a benefit of specialization. However, in-house staff are more successful at identifying and excluding affiliates whose practices are viewed as “borderline” (albeit still contrary to merchants’ interests), forgoing the efficiencies of specialization in favor of the better incentives of a company's staff. The authors consider the implications for marketing of online affiliate programs and for online marketing more generally.
Coleman–Gross height pairings and the p-adic sigma function
Authors: Balakrishnan Jennifer S. , Besser Amnon
Published: January 2015

We give a direct proof that the Mazur–Tate and Coleman–Gross heights
on elliptic curves coincide. The main ingredient is to extend the
Coleman–Gross height to the case of divisors with non-disjoint
support and, doing some p-adic analysis, show that, in particular,
its component above p gives, in the special case of an ordinary
elliptic curve, the p-adic sigma function.
We use this result to give a short proof of a theorem of Kim characterizing integral points
on elliptic curves in some cases under weaker assumptions. As a
further application, we give new formulas to compute double Coleman
integrals from tangential basepoints.
Population Genetics ofAnopheles coluzziiImmune Pathways and Genes
Authors: Rottschaefer Susan M , Crawford Jacob E , Riehle Michelle M , Guelbeogo Wamdaogo M , Gneme Awa , Sagnon N’Fale , Vernick Kenneth D , Lazzaro Brian P
Published: January 2015

Natural selection is expected to drive adaptive evolution in genes involved in host–pathogen interactions. In this study, we use molecular population genetic analyses to understand how natural selection operates on the immune system of Anopheles coluzzii (formerly A. gambiae “M form”). We analyzed patterns of intraspecific and interspecific genetic variation in 20 immune-related genes and 17 nonimmune genes from a wild population of A. coluzzii and asked if patterns of genetic variation in the immune genes are consistent with pathogen-driven selection shaping the evolution of defense. We found evidence of a balanced polymorphism in CTLMA2, which encodes a C-type lectin involved in regulation of the melanization response. The two CTLMA2 haplotypes, which are distinguished by fixed amino acid differences near the predicted peptide cleavage site, are also segregating in the sister species A. gambiae (“S form”) and A. arabiensis. Comparison of the two haplotypes between species indicates that they were not shared among the species through introgression, but rather that they arose before the species divergence and have been adaptively maintained as a balanced polymorphism in all three species. We additionally found that STAT-B, a retroduplicate of STAT-A, shows strong evidence of adaptive evolution that is consistent with neofunctionalization after duplication. In contrast to the striking patterns of adaptive evolution observed in these Anopheles-specific immune genes, we found no evidence of adaptive evolution in the Toll and Imd innate immune pathways that are orthologously conserved throughout insects. Genes encoding the Imd pathway exhibit high rates of amino acid divergence between Anopheles species but also display elevated amino acid diversity that is consistent with relaxed purifying selection. These results indicate that adaptive coevolution between A. coluzzii and its pathogens is more likely to involve novel or lineage-specific molecular mechanisms than the canonical humoral immune pathways.
hecd-1ModulatesNotchActivity inCaenorhabditis elegans
Authors: Chen Yunting , Greenwald Iva
Published: January 2015

Notch is a receptor that mediates cell–cell interactions that specify binary cell fate decisions in development and tissue homeostasis. Inappropriate Notch signaling is associated with cancer, and mutations in Notch pathway components have been associated with developmental diseases and syndromes. In Caenorhabditis elegans, suppressors of phenotypes associated with constitutively active LIN-12/Notch have identified many conserved core components and direct or indirect modulators. Here, we molecularly identify sel(ar584), originally isolated as a suppressor of a constitutively active allele of lin-12. We show that sel(ar584) is an allele of hecd-1, the ortholog of human HECDT1, a ubiquitin ligase that has been implicated in several different mammalian developmental events. We studied interactions of hecd-1 with lin-12 in the somatic gonad and with the other C. elegans Notch gene, glp-1, in the germ line. We found that hecd-1 acts as a positive modulator of lin-12/Notch activity in a somatic gonad context—the original basis for its isolation—but acts autonomously as a negative modulator of glp-1/Notch activity in the germ line. As the yeast ortholog of HECD-1, Ufd4p, has been shown to function in quality control, and C. elegansHECD-1 has been shown to affect mitochondrial maintenance, we propose that the different genetic interactions between hecd-1 and Notch genes we observed in different cell contexts may reflect differences in quality control regulatory mechanisms or in cellular metabolism.
Condensins Exert Force on Chromatin-Nuclear Envelope Tethers to Mediate Nucleoplasmic Reticulum Formation in Drosophila melanogaster
Authors: Bozler Julianna , Nguyen Huy Q , Rogers Gregory C , Bosco Giovanni
Published: January 2015

Although the nuclear envelope is known primarily for its role as a boundary between the nucleus and cytoplasm in eukaryotes, it plays a vital and dynamic role in many cellular processes. Studies of nuclear structure have revealed tissue-specific changes in nuclear envelope architecture, suggesting that its three-dimensional structure contributes to its functionality. Despite the importance of the nuclear envelope, the factors that regulate and maintain nuclear envelope shape remain largely unexplored. The nuclear envelope makes extensive and dynamic interactions with the underlying chromatin. Given this inexorable link between chromatin and the nuclear envelope, it is possible that local and global chromatin organization reciprocally impact nuclear envelope form and function. In this study, we use Drosophila salivary glands to show that the three-dimensional structure of the nuclear envelope can be altered with condensin II-mediated chromatin condensation. Both naturally occurring and engineered chromatin-envelope interactions are sufficient to allow chromatin compaction forces to drive distortions of the nuclear envelope. Weakening of the nuclear lamina further enhanced envelope remodeling, suggesting that envelope structure is capable of counterbalancing chromatin compaction forces. Our experiments reveal that the nucleoplasmic reticulum is born of the nuclear envelope and remains dynamic in that they can be reabsorbed into the nuclear envelope. We propose a model where inner nuclear envelope-chromatin tethers allow interphase chromosome movements to change nuclear envelope morphology. Therefore, interphase chromatin compaction may be a normal mechanism that reorganizes nuclear architecture, while under pathological conditions, such as laminopathies, compaction forces may contribute to defects in nuclear morphology.
Identification of New Players in Cell Division, DNA Damage Response, and Morphogenesis Through Construction of Schizosaccharomyces pombe Deletion Strains
Authors: Chen Jun-Song , Beckley Janel R , McDonald Nathan A , Ren Liping , Mangione MariaSanta , Jang Sylvia J , Elmore Zachary C , Rachfall Nicole , Feoktistova Anna , Jones Christine M , Willet Alaina H , Guillen Rodrigo , Bitton Danny A , Bähler Jürg , Jensen Michael A , Rhind Nick , Gould Kathleen L
Published: January 2015

Many fundamental biological processes are studied using the fission yeast, Schizosaccharomyces pombe. Here we report the construction of a set of 281 haploid gene deletion strains covering many previously uncharacterized genes. This collection of strains was tested for growth under a variety of different stress conditions. We identified new genes involved in DNA metabolism, completion of the cell cycle, and morphogenesis. This subset of nonessential gene deletions will add to the toolkits available for the study of biological processes in S. pombe.
Electro-Optical Detection of Single Nanoparticles on a Nanopore-Optofluidic Chip
Authors: Liu Shuo , Zhao Yue , Stott Matthew , Parks Joshua W. , Hawkins Aaron R. , Schmidt Holger
Published: January 2015

A solid-state nanopore was integrated into an optofluidic sensor chip, liquid-core anti-resonant reflecting optical waveguide (ARROW). The solid-state nanopore worked as a smart gate, which simultaneously provided characteristic electrical signals and controlled the entry of single nanoparticles into the liquid-core channel. The subsequent fluorescence detection further identified the nanoparticles by providing optical signals within a specific wavelength range. In this work, correlated electrical and optical detection of single nanoparticles, H1N1 viruses, and λ-DNA molecules was demonstrated. Different types of particles in a mixture were successfully discriminated. Moreover, the flow velocity in the liquid-core channel was extracted with the help of combined analysis of electrical and optical signals. Enhanced electrical sensitivity using a solid-state nanopore with a thin limiting aperture sculpted by SiO2 deposition was also shown.
PbS/CdS Core/Shell Nanocrystals For Solution-Processed Colloidal Quantum Dot Solar Cells
Authors: Neo Darren C. J. , Cheng Cheng , Assender Hazel E. , Watt Andrew A. R.
Published: January 2015

An epitaxial shell of cadmium sulphide is grown on lead sulphide quantum dots in order to reduce the concentration of surface defects. Thin solid films of these core/shell materials are found to have low carrier concentrations due to effective surface passivation which reduces the number of dangling bonds. In this paper PbS/CdS is used as a quasi-intrinsic layer in p-i-n photovoltaic devices where PbS acts as the p-layer and ZnO the n-layer. By studying different permutations of these layers and the degree of PbS p-type doping by annealing we optimise fill factor and open-circuit voltage.
Electrical Conductivity and Structural Order of p-Type Amorphous Silicon Thin Films
Authors: Shrestha K. , Whitfield D. , Lopes V. C. , Syllaios A. J. , Littler C.L.
Published: January 2015

The dependence of dark conductivity and room temperature Raman spectra on boron and hydrogen incorporation in thin films of hydrogenated amorphous silicon (a-Si:H) prepared by plasma enhanced chemical vapor deposition was investigated. It was found that the dominant conductivity is Mott variable range hopping conduction. However, at lower temperatures, Efros-Shklosvkii hopping conduction is observed and contributes to the total conductivity. For structural characterization, transverse optical (TO) and transverse acoustic (TA) modes of the Raman spectra were studied to relate changes in short- and mid-range order to the effects of boron and hydrogen incorporation. With an increase of hydrogen incorporation and/or substrate temperature, both short and mid-range order improve, whereas the addition of boron results in the degradation of the short range order. The line width and frequency of the Raman TO Raman peak correlate with electrical measurements and suggest that this technique can be used for non-destructive characterization of a-Si:H.
Weight, Length, and Body Mass Index Growth of Children under 2 Years of Age with Cleft Lip and Palate
Authors: Miranda Gabriela Serrano , Marques Ilza Lazarini , De Barros Suely Prietto , Arena Eliane Petean , De Souza Luiz
Published: January 2015

Objective

To study the growth of length-for-age (L/A), weight-for-age (W/A), and body mass index (BMI) of children with cleft lip and palate receiving a normal diet; to establish specific growth curves for children with cleft palate with or without cleft lip (CLP/ICP) who had not undergone palatoplasty and for children with isolated cleft lip (ICL); and to assess if CLP/ICP growth differed from ICL growth and if CLP/ICP and ICL growth differed from growth for typical children.

Design

Prospective and cross-sectional study.

Setting

Hospital for Rehabilitation of Craniofacial Anomalies, Bauru, São Paulo, Brazil.

Main Outcome Measures

Weight and length of 381 children with cleft lip and palate and who were younger than 2 years were recorded and used to calculate W/A, L/A, and BMI growth curves. The 2006 World Health Organization growth charts were used as a reference for typical children. All children received a normal diet for age.

Results

Children with CLP/ICP had median W/A and BMI growth curves below growth curves for typical children but showed spontaneous recovery starting at approximately 5 months of age, even with nonoperated cleft palate. Children with ICL had growth similar to that of typical children. Children with CLP/ICP, who initially had W/A and BMI values less than those of the ICL group, had W/A and BMI equal to or higher than the ICL group after 9 months of age.

Conclusion

Children with CLP/ICP had impaired W/A and BMI growth with spontaneous recovery starting early in childhood. This study established specific W/A, BMI, and L/A growth curves for children with cleft lip and palate.
Multidisciplinary Aspects of 104 Patients with Pierre Robin Sequence
Authors: Filip Charles , Feragen Kristin Billaud , Lemvik Jorunn Skartveit , Lindberg Nina , Andersson Els-Marie , Rashidi Mitra , Matzen Michael , Høgevold Hans Erik
Published: January 2015

Objective

To describe Pierre Robin sequence patients with a cleft palate from a multidisciplinary perspective.

Patients

A total of 104 individuals with Pierre Robin sequence and cleft palate, born between 1980 and 2010.

Method

Data were collected retrospectively and compared with large control groups.

Results

Of 104 patients, 19 (18.3%) were treated with a nasopharyngeal or oropharyngeal tube, continuous positive airway pressure, and/or a tracheotomy. The mean weight percentile for newborns with Pierre Robin sequence was 30.9. It decreased to 29.9 at the time of cleft palate repair (mean age, 13.7 months) ( P = .78). Of 87 patients, 30 (34.5%) developed normal speech after cleft palate repair. Of 93 nonsyndromic Pierre Robin sequence patients, 31 (33.3%) had or are having surgery for velopharyngeal insufficiency, a rate that is significantly higher when compared with a control group of cleft palate–only patients (19.4%; P = .004). Of 31 patients, 25 (80.6%) developed normal resonance after surgery for velopharyngeal insufficiency. There was no significant difference in the rate of syndromes between the Pierre Robin sequence patients and a control group of cleft palate patients without Pierre Robin sequence ( P = .25). Seven of 39 boys (17.9%) with Pierre Robin sequence had a diagnosis of autism spectrum disorder.

Conclusion

Even though the mean weight percentile for newborns with Pierre Robin sequence was low, the patients did not show a growth spurt during the first year of life. The high rate of velopharyngeal insufficiency after cleft palate repair in patients with Pierre Robin sequence needs further investigation. Also, the high rate of autism spectrum disorder among boys with Pierre Robin sequence prompts further investigation.
A Novel Water-Injectivity Model and Experimental Validation With CT-Scanned Corefloods
Authors: Yerramilli Ramesh Chandra , Zitha P.L.J.. L.J. , Yerramilli Sanjay Surya , Bedrikovetsky Pavel
Published: January 2015

Injectivity decline is an issue during produced-water reinjection (PWRI) for water disposal in aquifers, waterflooding, chemical enhanced oil recovery, and geothermal-energy exploitation. A novel model for injectivity decline under flow conditions reminiscent of PWRI was developed taking into account deep-bed filtration and buildup of external filter cake. A distinct feature of the model is that it describes particle-retention kinetics responsible for internal filtration by an exponential decaying function of the retained-particle concentration. The corresponding nonlinear governing partial-differential equations were solved numerically and coupled with a known analytical model for external filtration with the concept of transition time. Coreflood experiments consisting of the injection of brine containing suspended hematite particles (volume fractions in the range of 2 to 6 ppm) were also performed. Computed-tomography (CT) scans of the core were taken to obtain deposition profiles along the core at different times. In addition, effect of various parameters (particle concentration and number of grids) on injectivity was investigated. From CT-scan and optical-microscope analyses, it was found that surface deposition in the porous medium and face plugging at the injection face of the core were responsible for decline in injectivity. The transition time from pure internal to external filtration was accurately determined from the CT-scan and pressure data. The newly proposed model and experiments were found to be in excellent agreement, indicating that the adopted retention function is a good heuristic description of particle retention.
Understanding Shale Gas Flow Behavior Using Numerical Simulation
Authors: Sun Hao , Chawathé Adwait , Hoteit Hussein , Shi Xundan , Li Lin
Published: January 2015

Shale gas has changed the energy equation around the world, and its impact has been especially profound in the United States. It is now generally agreed that the fabric of shale systems comprises primarily organic matter, inorganic material, and natural fractures. However, the underlying flow mechanisms through these multiporosity and multipermeability systems are poorly understood. For instance, debate still exists about the predominant transport mechanism (diffusion, convection, and desorption), as well as the flow interactions between organic matter, inorganic matter, and fractures. Furthermore, balancing the computational burden of precisely modeling the gas transport through the pores vs. running full reservoir scale simulation is also contested. To that end, commercial reservoir simulators are developing new shale gas options, but some, for expediency, rely on simplification of existing data structures and/or flow mechanisms.

We present here the development of a comprehensive multimechanistic (desorption, diffusion, and convection), multiporosity (organic materials, inorganic materials, and fractures), and multipermeability model that uses experimentally determined shale organic and inorganic material properties to predict shale gas reservoir performance. Our multimechanistic model takes into account gas transport caused by both pressure driven convection and concentration driven diffusion. The model accounts for all the important processes occurring in shale systems, including desorption of multicomponent gas from the organics' surface, multimechanistic organic/inorganic material mass transfer, multimechanistic inorganic material/fracture network mass transfer, and production from a hydraulically fractured wellbore.

Our results show that a dual porosity, dual permeability (DPDP) model with Knudsen diffusion is generally adequate to model shale gas reservoir production. Adsorption can make significant contributions to original gas in place, but is not important to gas production because of adsorption equilibrium. By comparing triple porosity, dual permeability; DPDP; and single porosity, single permeability formulations under similar conditions, we show that Knudsen diffusion is a key mechanism and should not be ignored under low matrix pressure (Pematrix) cases, whereas molecular diffusion is negligible in shale dry gas production. We also guide the design of fractures by analyzing flow rate limiting steps. This work provides a basis for long term shale gas production analysis and also helps define value adding laboratory measurements.
The First Visualization of Acid Treatments on Carbonates With 3D Nuclear-Magnetic-Resonance Imaging
Authors: Krebs M.. , Lungwitz B.. , Souza A.. , Pépin A.. , Montoya S.. , Schlicht P.. , Boyd A.. , Vidoto E.. , Polli R.. , Bonagamba T..
Published: January 2015

Carbonate reservoirs often show great heterogeneity in their inner rock structure, and stimulation treatments are often necessary to maintain or establish fluid production. Therefore, core-flow tests are usually conducted to test and model stimulation treatments within a laboratory scale to predict their performance. The visualization of wormholes that were created within core-flow tests requires novel technologies for evaluation and pathway-prediction purposes. Unfortunately, past visualization techniques were always associated with the destruction of the core sample, creating a demand for nondestructive methods.

Nuclear-magnetic-resonance imaging (NMRI) is such a method that fulfills the approach of being nondestructive. The technology is widely known by medical applications, and this study developed a procedure on how to use the NMRI technology to visualize wormholes with NMRI in 3D.

The study was started by initially choosing and obtaining various core samples that have different contents of calcite and dolomite. These core samples were imaged with the NMRI and microfocus-computed-tomography (µCT) technology in their unchanged state, and basic petrophysical experiments were conducted for initial experiments. The μCT technology was used as a reference visualization technique, because it provides a very high resolution with a corresponding high level of detail. Afterward, core-flow tests were conducted on the core samples with various acid systems and wormholes generated. Finally, the core samples with wormholes were imaged again with the NMRI and μCT technology, whereby the NMRI acquisition technique was improved toward imaging of rock samples, and the results were compared with the μCT results. The NMRI results showed moderate imaging achievements for the unchanged rock samples and high-quality imaging achievements for the extracted wormholes.
Dynamic Modeling of Channel Formation During Fluid Injection Into Unconsolidated Formations
Authors: Ameen S.. , Taleghani A. Dahi
Published: January 2015

Injectivity loss is a common problem in unconsolidated-sand formations. Injection of water into a poorly cemented granular medium may lead to internal erosion, and consequently formation of preferential flow paths within the medium because of channelization. Channelization in the porous medium might occur when fluid-induced stresses become locally larger than a critical threshold and small grains are dislodged and carried away; hence, porosity and permeability of the medium will evolve along the induced flow paths. Vice versa, flowback during shut-in might carry particles back to the well and cause sand accumulation inside the well, and subsequently loss of injectivity. In most cases, to maintain the injection rate, operators will increase injection pressure and pumping power. The increased injection pressure results in stress changes and possibly further changes in channel patterns around the wellbore. Experimental laboratory studies have confirmed the presence of the transition from uniform Darcy flow to a fingered-pattern flow. To predict these phenomena, a model is needed to fill this gap by predicting the formation of preferential flow paths and their evolution. A model based on the multiphase-volume-fraction concept is used to decompose porosity into mobile and immobile porosities where phases may change spatially, evolve over time, and lead to development of erosional channels depending on injection rates, viscosity, and rock properties. This model will account for both particle release and suspension deposition. By use of this model, a methodology is proposed to derive model parameters from routine injection tests by inverse analysis. The proposed model presents the characteristic behavior of unconsolidated formation during fluid injection and the possible effect of injection parameters on downhole-permeability evolution.
Evaluation of the effects of hospital visit stress on physiologic variables in dogs
Authors: Bragg Ryan F. , Bennett Jennifer S. , Cummings Annelise , Quimby Jessica M.
Published: January 2015

Objective—To evaluate differences in pulse rate, rectal temperature, respiratory rate, and systolic arterial blood pressure in dogs between the home and veterinary hospital environments.

Design—Prospective observational study.

Animals—30 client-owned healthy dogs.

Procedures—Study dogs had respiratory rate, pulse rate, rectal temperature, and systolic arterial blood pressure measured in their home environment. Dogs were then transported to the veterinary hospital, and measurements were repeated.

Results—Significant differences in blood pressure, rectal temperature, and pulse rate were observed between measurements obtained in the home and hospital environments. Mean blood pressure increased by 16% (95% confidence interval [CI], 8.8% to 24%), rectal temperature increased by < 1% (95% CI, 0.1% to 0.6%), and pulse rate increased by 11% (95% CI, 5.3% to 17.6%). The number of dogs panting in the hospital environment (19/30 [63%]) was significantly higher than the number of dogs panting in the home environment (5/30 [17%])

Conclusions and Clinical Relevance—Results of the present study suggested that practitioners should consider stress from transportation and environmental change when canine patients have abnormalities of vital signs on initial examination, and the variables in question should be rechecked before a definitive diagnosis of medical illness is reached or extensive further workup is pursued.
Double pigtail ureteral stenting and renal pelvic lavage for renal-sparing treatment of obstructive pyonephrosis in dogs: 13 cases (2008–2012)
Authors: Kuntz Jodi A. , Berent Allyson C. , Weisse Chick W. , Bagley Demetrius H.
Published: January 2015

Objective—To describe the technical aspects and clinical outcome of endoscopic- and fluoroscopic-guided ureteropelvic lavage and ureteral stent placement for treatment of obstructive pyonephrosis in dogs.

Design—Retrospective case series.

Animals—13 client-owned dogs (14 obstructed ureters).

Procedures—All patients with obstructive pyonephrosis were treated with a ureteral stent. Medical records were reviewed for history, clinical signs, pre- and postprocedural clinical and imaging data, and short- and long-term outcomes.

Results—13 dogs (14 ureters) had unilateral or bilateral ureteral obstructions and pyonephrosis due to ureterolithiasis (n = 13) or a suspected ureteral stricture (1). Eleven dogs had positive results of bacteriologic culture of urine obtained from the bladder, renal pelvis, or both. Ten were thrombocytopenic, and 8 were azotemic. Stents were placed fluoroscopically with endoscopic (n = 11) or surgical (3) assistance. Median hospitalization time was 48 hours (range, 6 to 260 hours). Median follow-up time was 480 days (range, 2 to 1,460 days). Intraoperative complications occurred in 2 patients (stent occlusion from shearing of a guide wire, and wire penetration of the ureter at the location of a stone). Short-term complications included a bladder hematoma (n = 1) and transient dysuria (1). Long-term complications included stent encrustation (n = 1), stent migration (1), and tissue proliferation at the ureterovesicular junction (5), which had no clinical implications. Recurrent urinary tract infections were documented in 7 dogs.

Conclusions and Clinical Relevance—Ureteral stenting was a successful renal-sparing treatment for obstructive pyonephrosis in dogs and could often be performed in a minimally invasive manner. There were few major complications. This technique may be considered as an effective treatment option for this condition in dogs.
Unilateral choristoma of the nictitating membrane in a horse
Authors: Gornik Kara R. , Pirie Christopher G. , Beamer Gillian L.
Published: January 2015

Case Description—A 2-year-old Morgan mare was evaluated because of a corneal ulceration.

Clinical Findings—An irregular, deep stromal corneal ulcer in an area of malacia was noted in the left eye. Hypopyon was present in the ventral portion of the anterior chamber with moderate aqueous flare. The nictitating membrane of the left eye had hairs originating from its leading edge that contacted the corneal surface.

Treatment and Outcome—General anesthesia was induced, and a bulbar pedicle conjunctival graft was performed. The conjunctiva at the leading edge of the nictitating membrane, including the aberrant hair follicles, was excised. Microscopically, a nonkeratinized stratified squamous epithelium, sebaceous glands, and hair shafts were present, confirming a choristoma of pilosebaceous origin at the leading edge of the nictitating membrane. Six weeks after surgery, the horse had no signs of discomfort, with no regrowth of the hairs; no loss of vision was evident.

Clinical Relevance—Ocular choristomas develop secondary to defective fetal cellular differentiation and are rarely reported in the equine literature. The choristoma in this horse contained ectopic hair follicles with hair growth as well as sebaceous glands. This finding emphasizes the importance of a thorough adnexal examination in horses with corneal disease.
Sensitivity and specificity of repeated test results from a commercial milk enzyme-linked immunosorbent assay for detection of Mycobacterium avium subspecies paratuberculosis in dairy cattle
Authors: Lavers Carrie J. , Dohoo Ian R. , McKenna Shawn L. B. , Keefe Greg P.
Published: January 2015

Objective—To investigate the sensitivity and specificity of results of initial and repeated milk ELISAs (at 6- or 12-month intervals) to detect cows that were shedding Mycobacterium avium subsp paratuberculosis (ie, were infectious) and to evaluate factors influencing the probability that the results of a repeated milk ELISA would be positive for an infectious cow if the results of the initial milk ELISA were negative.

Design—Prospective cohort study.

Animals—3,145 dairy cows from 32 herds.

Procedures—Herds from the 3 Maritime provinces in Canada (Prince Edward Island, New Brunswick, and Nova Scotia), participating in a Dairy Herd Improvement program, and that had undergone a prior Mycobacterium avium subsp paratuberculosis awareness project were selected for the study. Sample collection occurred between April 2009 and March 2011 with milk and fecal samples collected from all lactating cows in study herds every 6 months. Herds completing < 3 herd visits with collection of individual cow fecal or milk samples, within this sampling timeframe, were excluded from analyses. Fecal samples were cultured in liquid medium and a cow was defined as infectious if ≥ 1 sample was culture positive (reference test). A milk ELISA (index test) was completed with a commercial kit, following manufacturer's instructions.

Results—For a 6-month test interval, sensitivities of the milk ELISA to detect infectious cows were 22.0% and 32.6% for initial and combined initial and repeated tests (parallel interpretation), respectively. Specificity of the initial ELISA was 99.6% and was 99.2% for combined tests. For a 12-month test interval, sensitivities of the milk ELISA to detect infectious cows were 25.6% and 45.3% for initial and combined initial and repeated tests (parallel interpretation), respectively. Specificity of the initial ELISA was 99.6% and was 98.9% for combined tests. In infectious cows, magnitude of the initial negative ELISA result was a positive predictor for a positive repeated ELISA result.

Conclusions and Clinical Relevance—Results of a repeated milk ELISA improved detection of Mycobacterium avium subsp paratuberculosis infectious cows, with minimal loss of specificity. A 12-month test interval provided a greater increase in sensitivity, relative to an initial test, than did a 6-month interval. Infectious cows with an initial negative milk ELISA result close to the cutoff for a positive test were more likely to have positive results on a repeated ELISA. Repeated testing improved detection of infectious cows and reduced risk of misclassification compared with a single ELISA result.