Road Traffic Emissions Lead to Much Enhanced New Particle Formation through Increased Growth Rates

New particle formation (NPF) is a major source of atmospheric aerosol particles, including cloud condensation nuclei (CCN), by number globally. Previous research has highlighted that NPF is less frequent but more intense at roadsides compared to urban background. Here, we closely examine NPF at both background and roadside sites in urban Central Europe. We show that the concentration of oxygenated organic molecules (OOMs) is greater at the roadside, and the condensation of OOMs along with sulfuric acid onto new particles is sufficient to explain the growth at both sites. We identify a hitherto unreported traffic-related OOM source contributing 29% and 16% to total OOMs at the roadside and background, respectively. Critically, this hitherto undiscovered OOM source is an essential component of urban NPF. Without their contribution to growth rates and the subsequent enhancements to particle survival, the number of &gt;50 nm particles produced by NPF would be reduced by a factor of 21 at the roadside site. Reductions to hydrocarbon emissions from road traffic may thereby reduce particle numbers and CCN counts.</p

Pienhiukkasten haihtuvuusmittaukseen käytettävän FIGAERO-ToF-CIMS-laitteiston karakterisointi

Ilmakehän aerosolit vaikuttavat maapalloon ja ihmiskuntaan monin tavoin, kuten säteilypakotteena ja terveysongelmia aiheuttavina hiukkaspäästöinä. Aerosolit jaetaan kemiallisen koostumuksensa perusteella orgaanisiin ja epäorgaanisiin aerosoleihin, ja aerosolihiukkaset voidaan muodostumisreittinsä perusteella luokitella primäärisiin ja sekundäärisiin aerosolihiukkasiin. Primääriset hiukkaset ovat jo ilmakehään päätyessään tiivistyneessä faasissa, kun taas sekundääriset hiukkaset muodostuvat ilmakehässä kaasuista erilaisten prosessien myötä. Ilmakehässä olevan kaasun kylläinen höyrynpaine kuvaa sitä, kuinka todennäköisesti kaasu tiivistyy hiukkasfaasiin. Tämän vuoksi aerosoleja tutkiessa on hyödyllistä tietää sen sisältämien yhdisteiden kylläisiä höyrynpaineita. Tässä kandidaatintyössä perehdytään sekundääriseen orgaaniseen aerosoliin ja suoritetaan karakterisointi ja kalibrointi FIGAERO-ToF-CIMS-laitteistolle (Filter Inlet for Gases and AEROsols, Time-of-Flight Chemical Ionisation Mass Spectrometer). FIGAERO-ToF-CIMS on laitteisto, jolla voidaan selvittää ympäröivän ilman kaasu- ja hiukkaskoostumusta sekä mitattavien yhdisteiden kylläisiä höyrynpaineita, mistä johtuen laitteisto sopii haihtuvuusmittauksiin ja aerosolin tutkimiseen. FIGAERO-ToF-CIMS koostuu FIGAEROsta, joka on moniporttinen näytteenottolaite massaspektrometrille, ja ToF-CIMS:stä, eli kemiallisesti ionisoitujen molekyylien lentoajan mittaukseen perustuvasta massaspektrometristä. Jokainen FIGAERO on ominaisuuksiltaan yksilöllinen, joten ne on kalibroitava kappalekohtaisesti. FIGAEROn kalibrointiin käytetään kahta eri tapaa: pipetointimetodia ja pirskotinmetodia. Tämän työn kokeellisissa mittauksissa käytettiin pipetointimetodia. Kalibrointistandardeina käytettiin polyetyleeniglykoleja PEG-6 ja PEG-8 asetonitriiliin liuotettuina. Kalibrointistandardeille määritettiin kalibraatiokertoimet, joiden avulla voidaan jatkossa laskea pelkästä massaspektrometrin signaalista FIGAEROn suodattimella ollut massa. Mittaustulokset osoittavat, että laitteisto havaitsee PEG-8:aa paremmin kuin PEG-6:ta. Voi olla, että laitteisto havaitsee paremmin suurempimassaisia molekyylejä, sillä PEG-8:n moolimassa on suurempi kuin PEG-6:n. Muita mahdollisia selityksiä havaintotehokkuuksien erolle on, että PEG-8 ionisoituu tai kulkee laitteiston läpi todennäköisemmin kuin PEG-6. Laitteiston mallintamisen parantamiseksi olisi hyvä tutkia havaintotehokkuuksia myös epäorgaanisilla ja erilaisia funktionaalisia ryhmiä sisältävillä yhdisteillä. PEG-liuoksille määritettiin myös Tmax-arvot, eli lämpötilat, joissa massaspektrometrin havaitsema signaali on korkeimmillaan. Tmax-arvojen avulla voidaan määrittää yhdisteiden kylläisiä höyrynpaineita. Tmax-arvojen todettiin pysyvän pienillä massoilla lähestulkoon vakiona, mutta suurilla massoilla ne kasvavat massan kasvaessa. Tämä Tmax-arvojen riippuvuus massasta suurilla massoilla tulee ottaa huomioon mittaustekniikassa, kun laitteistoa käytetään todellisiin mittauksiin

Road Traffic Emissions Lead to Much Enhanced New Particle Formation through Increased Growth Rates

New particle formation (NPF) is a major source of atmospheric aerosol particles, including cloud condensation nuclei (CCN), by number globally. Previous research has highlighted that NPF is less frequent but more intense at roadsides compared to urban background. Here, we closely examine NPF at both background and roadside sites in urban Central Europe. We show that the concentration of oxygenated organic molecules (OOMs) is greater at the roadside, and the condensation of OOMs along with sulfuric acid onto new particles is sufficient to explain the growth at both sites. We identify a hitherto unreported traffic-related OOM source contributing 29% and 16% to total OOMs at the roadside and background, respectively. Critically, this hitherto undiscovered OOM source is an essential component of urban NPF. Without their contribution to growth rates and the subsequent enhancements to particle survival, the number of &gt;50 nm particles produced by NPF would be reduced by a factor of 21 at the roadside site. Reductions to hydrocarbon emissions from road traffic may thereby reduce particle numbers and CCN counts.</p

GATA4-dependent organ-specific endothelial differentiation controls liver development and embryonic hematopoiesis

Abstract Microvascular endothelial cells (ECs) are increasingly recognized as organ-specific gatekeepers of their microenvironment. Microvascular ECs instruct neighboring cells in their organ-specific vascular niches through angiocrine factors, which include secreted growth factors (angiokines), extracellular matrix molecules, and transmembrane proteins. However, the molecular regulators that drive organ-specific microvascular transcriptional programs and thereby regulate angiodiversity are largely elusive. In contrast to other ECs, which form a continuous cell layer, liver sinusoidal ECs (LSECs) constitute discontinuous, permeable microvessels. Here, we have shown that the transcription factor GATA4 controls murine LSEC specification and function. LSEC-restricted deletion of Gata4 caused transformation of discontinuous liver sinusoids into continuous capillaries. Capillarization was characterized by ectopic basement membrane deposition, formation of a continuous EC layer, and increased expression of VE-cadherin. Correspondingly, ectopic expression of GATA4 in cultured continuous ECs mediated the downregulation of continuous EC-associated transcripts and upregulation of LSEC-associated genes. The switch from discontinuous LSECs to continuous ECs during embryogenesis caused liver hypoplasia, fibrosis, and impaired colonization by hematopoietic progenitor cells, resulting in anemia and embryonic lethality. Thus, GATA4 acts as master regulator of hepatic microvascular specification and acquisition of organ-specific vascular competence, which are indispensable for liver development. The data also establish an essential role of the hepatic microvasculature in embryonic hematopoiesis

Female leadership and welfare state reform: the development of Australia’s first national paid parental leave scheme

The Howard Government's commitment to supporting the male breadwinner policy model was a major barrier to the efforts of female political leaders to influence the development of a national paid parental leave scheme. Associated with this model was the argument that paid parental leave 'discriminated' against nonworking women and devalued their contribution to society as mothers. Despite a change of government in 2007 this argument remained influential through the Productivity Commission's Inquiry into Paid Maternity, Paternity and Parental Leave (2009). Key to the eventual legislation of the scheme in 2010 was female leaders' strategy of aligning with, rather than disrupting, this narrative. As such, women in trade unions, political parties, women's groups and the bureaucracy framed paid parental leave as supporting women in their maternal roles as it allowed them the financial breathing room to stay at home for longer with their newborn

Functional hemispheric disconnection procedures for chronic epilepsy: history, indications, techniques, complications and current practice in Europe. A consensus statement on behalf of the EANS functional neurosurgery section

Introduction: The surgical procedure for severe, drug-resistant, unilateral hemispheric epilepsy is challenging. Over the last decades the surgical landscape for hemispheric disconnection procedures changed from anatomical hemispherectomy to functional hemispherotomy with a reduction of complications and stable good seizure outcome. Here, a task force of European epilepsy surgeons prepared, on behalf of the EANS Section for Functional Neurosurgery, a consensus statement on different aspects of the hemispheric disconnection procedure. Research question: To determine history, indication, timing, techniques, complications and current practice in Europe for hemispheric disconnection procedures in drug-resistant epilepsy. Material and methods: Relevant literature on the topic was collected by a literature search based on the PRISMA 2020 guidelines. Results: A comprehensive overview on the historical development of hemispheric disconnection procedures for epilepsy is presented, while discussing indications, timing, surgical techniques and complications. Current practice for this procedure in European epilepsy surgery centers is provided. At present, our knowledge of long-term seizure outcomes primarily stems from open surgical disconnection procedures. Although minimal invasive surgical techniques in epilepsy are rapidly developing and reported in case reports or small case series, long-term seizure outcome remain uncertain and needs to be reported. Discussion and conclusion: This is the first paper presenting a European consensus statement regarding history, indications, techniques and complications of hemispheric disconnection procedures for different causes of chronic, drug-resistant epilepsy. Furthermore, it serves as the pioneering document to report a comprehensive overview of the current surgical practices regarding this type of surgery employed in renowned epilepsy surgery centers across Europe.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Functional hemispheric disconnection procedures for chronic epilepsy : history, indications, techniques, complications and current practice in Europe. A consensus statement on behalf of the EANS functional neurosurgery section

Introduction: The surgical procedure for severe, drug-resistant, unilateral hemispheric epilepsy is challenging. Over the last decades the surgical landscape for hemispheric disconnection procedures changed from anatomical hemispherectomy to functional hemispherotomy with a reduction of complications and stable good seizure outcome. Here, a task force of European epilepsy surgeons prepared, on behalf of the EANS Section for Functional Neurosurgery, a consensus statement on different aspects of the hemispheric disconnection procedure. Research question: To determine history, indication, timing, techniques, complications and current practice in Europe for hemispheric disconnection procedures in drug-resistant epilepsy. Material and methods: Relevant literature on the topic was collected by a literature search based on the PRISMA 2020 guidelines. Results: A comprehensive overview on the historical development of hemispheric disconnection procedures for epilepsy is presented, while discussing indications, timing, surgical techniques and complications. Current practice for this procedure in European epilepsy surgery centers is provided. At present, our knowledge of long-term seizure outcomes primarily stems from open surgical disconnection procedures. Although minimal invasive surgical techniques in epilepsy are rapidly developing and reported in case reports or small case series, long-term seizure outcome remain uncertain and needs to be reported. Discussion and conclusion: This is the first paper presenting a European consensus statement regarding history, indications, techniques and complications of hemispheric disconnection procedures for different causes of chronic, drug-resistant epilepsy. Furthermore, it serves as the pioneering document to report a comprehensive overview of the current surgical practices regarding this type of surgery employed in renowned epilepsy surgery centers across Europe.Peer reviewe