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New particle formation in the upper free troposphere is a major global source of cloud condensation nuclei (CCN)1,2,3,4. However, the precursor vapours that drive the process are not well understood. With experiments performed under upper tropospheric conditions in the CERN CLOUD chamber, we show that nitric acid, sulfuric acid and ammonia form particles synergistically, at rates that are orders of magnitude faster than those from any two of the three components. The importance of this mechanism depends on the availability of ammonia, which was previously thought to be efficiently scavenged by cloud droplets during convection. However, surprisingly high concentrations of ammonia and ammonium nitrate have recently been observed in the upper troposphere over the Asian monsoon region5,6. Once particles have formed, co-condensation of ammonia and abundant nitric acid alone is sufficient to drive rapid growth to CCN sizes with only trace sulfate. Moreover, our measurements show that these CCN are also highly efficient ice nucleating particles—comparable to desert dust. Our model simulations confirm that ammonia is efficiently convected aloft during the Asian monsoon, driving rapid, multi-acid HNO3–H2SO4–NH3 nucleation in the upper troposphere and producing ice nucleating particles that spread across the mid-latitude Northern Hemisphere.
Background: To assess the influence of ridge preservation procedures on the healing of extraction sockets under antiresorptive therapy.
Material and Methods: A total of 10 Dutch Belted rabbits were randomly allocated to either the intravenous administration of amino‐bisphosphonate (zoledronic acid) (Za) (n = 5) or a negative control group (no Za [nZa]) (n = 5). At 6 months, the mandibular and maxillary molars were extracted and the four experimental sites randomly allocated to the following subgroups: (a) socket grafting using a collagen‐coated natural bone mineral (BOC) + primary wound closure, (b) coronectomy (CO), or (c) spontaneous healing + primary wound closure (SP). Za medication was continued for another 4 months. Histomorphometrical analyses considered, for example, crestal hard tissue closure of the extraction site (C) and mineralized tissue (MT) formation.
Results: Za‐SP was associated with an incomplete median C (31.76% vs 100% in nZa‐SP) and signs of bone arrosion along the confines of the socket. BOC had no major effects on increases in C and MT values in the Za group. CO commonly resulted in an encapsulation and partial replacement resorption of residual roots by MT without any histological signs of osteonecrosis.
Conclusions: (a) Za‐SP was commonly associated with a compromised socket healing and signs of osteonecrosis, (b) BOC had no major effect on socket healing in the Za group, and (c) CO at noninfected teeth might be a feasible measure for the prevention of a Za‐related osteonecrosis of the jaw.
Objective: To assess the influence of biphasic calcium phosphate materials with different surface topographies on bone formation and osseointegration of titanium implants in standardized alveolar ridge defects.
Materials and methods: Standardized alveolar ridge defects (6 × 6 mm) were created in the mandible of 8 minipigs and filled with three biphasic calcium phosphate materials (BCP1–3, 90% tricalcium phosphate/10% hydroxyapatite) with different surface properties (micro- and macroporosities) as well as a bovine-derived natural bone mineral (NBM) as a control. At 12 weeks, implants were placed into the augmented defects. After further 8 weeks of healing, dissected blocks were processed for histological analysis (e.g., mineralized (MT), residual bone graft material (BS), bone-to-implant contact (BIC)).
Results: All four biomaterials showed well-integrated graft particles and new bone formation within the defect area. MT values were comparable in all groups. BS values were highest in the NBM group (21.25 ± 13.52%) and markedly reduced in the different BCP groups, reaching statistical significance at BCP1-treated sites (9.2 ± 3.28%). All test and control groups investigated revealed comparable and statistically not significant different BIC values, ranging from 73.38 ± 20.5% (BCP2) to 84.11 ± 7.84% (BCP1), respectively.
Conclusion* All bone graft materials facilitated new bone formation and osseointegration after 12 + 8 weeks of healing.
Species of Calloeneis Grote (Coleoptera: Coccinellidae) are discussed, and a key to all recognized species is provided. New species described are C. alexandra, C. angelica, C. blanca, C. bennetti, C. bethany, C.brooke, C. francis, C. jacquelin, C. johnnie, C. kara, C. krista, C. leticia, C. lynne, C. robyn, C. marianne, C. myra,C. rosalie, C. roxanne and C. sheri, all authored by Gordon and Hanley.
Twenty new species are described in Pentilia Mulsant (Coleoptera: Coccinellidae: Scymninae: Cryptognathini) by Gordon and González: Pentilia bernadette, P. chelsea, P. dianna, P. elena, P. ernestine, P. estelle, P. kari, P. jasmine, P. jody, P. kendra. P. krystal, P. lora, P. mable, P. muriel, P. nichole, P. nadine. P. paulette, P. rachael, P. sadie and P. traci. A lectotype is here designated for Pentilia egena Mulsant.
Genera of Cryptognathini (Coleoptera: Coccinellidae) are discussed and a key to all recognized genera is provided. Cryptognatha is revised, and species of this genus are keyed. New species, authored by González and Hanley, are Cryptognatha pam, C. kellie, C. hannah, C. whitney, C. karla, C. celia, C. shelia, C. gayle, C. della and C. vicki. The following new synonymies are proposed: Cryptognatha simillima Sicard = Cryptognatha gemellata Mulsant, Cryptognatha fryii Crotch = Cryptognatha pudibunda Mulsant, Cryptognatha bryanti Brèthes = Cryptognatha pudibunda Mulsant. Lectotypes are here designated for Cryptognatha amicta Gorham, C. weisei Brèthes, C. pudibunda Mulsant and C. fryii Crotch.
Nucleation and growth of aerosol particles from atmospheric vapors constitutes a major source of global cloud condensation nuclei (CCN). The fraction of newly formed particles that reaches CCN sizes is highly sensitive to particle growth rates, especially for particle sizes <10 nm, where coagulation losses to larger aerosol particles are greatest. Recent results show that some oxidation products from biogenic volatile organic compounds are major contributors to particle formation and initial growth. However, whether oxidized organics contribute to particle growth over the broad span of tropospheric temperatures remains an open question, and quantitative mass balance for organic growth has yet to be demonstrated at any temperature. Here, in experiments performed under atmospheric conditions in the Cosmics Leaving Outdoor Droplets (CLOUD) chamber at the European Organization for Nuclear Research (CERN), we show that rapid growth of organic particles occurs over the range from −25 ∘C to 25 ∘C. The lower extent of autoxidation at reduced temperatures is compensated by the decreased volatility of all oxidized molecules. This is confirmed by particle-phase composition measurements, showing enhanced uptake of relatively less oxygenated products at cold temperatures. We can reproduce the measured growth rates using an aerosol growth model based entirely on the experimentally measured gas-phase spectra of oxidized organic molecules obtained from two complementary mass spectrometers. We show that the growth rates are sensitive to particle curvature, explaining widespread atmospheric observations that particle growth rates increase in the single-digit-nanometer size range. Our results demonstrate that organic vapors can contribute to particle growth over a wide range of tropospheric temperatures from molecular cluster sizes onward.
Genera of Cephaloscymnini (Coleoptera: Coccinellidae: Coccidulinae) are discussed and a key to all recognized genera and species is provided. Succinctonotum, new genus, is proposed. Scymnus laboulbenii Mulsant and Prodilis maculata Weise are transferred to Neaporia as new combinations. Prodiloides bipunctata Weise, and Neaporia compta are transferred to Prodilis as new combinations. Neaporia cuprea Gorham is considered a junior synonym of Neaporia viridiscens Gorham and Cephaloscymnus bruchi Weise a junior synonym of Prodilis volgus Mulsant. New species described in Cephaloscymnus are C. beulah, C. candice, C. juanita. New species described in Neaporia are N. becky, N. bobbie, N. brandy, N. carole, N. cassandra, N. christy, N. daisy, N. deanna, N. dianne, N. felicia, N. gwendolyn, N. hilda, N. irma, N. jennie, N. jenny, N. kay, N. kayla, N. kristine, N. leah, N. lena, N. leona, N. longifrons, N. mabel, N. mae, N. margie, N. marsha, N. miriam, N. misty, N. myrtle, N. naomi, N. nina, N. nora, N. olga, N. opal, N. patsy, N. penny, N. priscilla, N. shelley, N. sonia, N. tracey, and N. violet. New species described in Succinctonotum is S. frosti. New species described in Prodilis are P. ada, P. alberta, P. alison, P. amelia, P. angie, P. araguaensis, P. bartletti, P. belinda, P. blanche, P. brandi, P. cecilia, P. claire, P. cora, P. dubitalis, P. erika, P. eunice, P. fannie, P. faye, P. flora, P. geneva, P. guadalupe, P. harriet, P. hattie, P. inez, P. iris, P. isabel, P. jan, P. janie, P. joanna, P. jodi, P. katrina, P. kristi, P. kristy, P. lindsey, P. lola, P. lula, P. lynda, P. madeline, P. maggie, P. mamie, P. margarita, P. maryann, P. melody, P. molly, P. monique, P. natasha, P. olivia, P. pecki, P. ramona, P. rosie, P. sabrina, P. sandy, P. shelley, P. sherri, P. sheryl, P. sonya, P. susie, and P. yvette. Ponaria, new genus of Coccidulini is proposed. Neaporia caerulea Gorham is transferred to Ponaria as a new combination. New species described in Ponaria are P. daviesi, P. hurtadoi, and P. paprzyckii. Lectotypes are here designated for Neaporia arrowi, N. coelestis, N. metallica, N. guatemalana, N. indagator, and Prodilis pallidifrons.
A systematic redefinition of the species belonging to the genus Geomyphilus Gordon and Skelley, 2007 (Coleoptera: Scarabaeidae: Aphodiinae) of Mexico and neighboring countries is presented. The new species G. tuzincola of Mexico is described and figured. The new combination Coelotrachelus macgregori (Islas, 1955) is proposed.
The formation of secondary particles in the atmosphere accounts for more than half of global cloud condensation nuclei. Experiments at the CERN CLOUD (Cosmics Leaving OUtdoor Droplets) chamber have underlined the importance of ions for new particle formation, but quantifying their effect in the atmosphere remains challenging. By using a novel instrument setup consisting of two nano-particle counters, one of them equipped with an ion filter, we were able to further investigate the ion-related mechanisms of new particle formation. In autumn 2015, we carried out experiments at CLOUD on four systems of different chemical compositions involving monoterpenes, sulfuric acid, nitrogen oxides, and ammonia. We measured the influence of ions on the nucleation rates under precisely controlled and atmospherically relevant conditions. Our results indicate that ions enhance the nucleation process when the charge is necessary to stabilize newly formed clusters, i.e. in conditions where neutral clusters are unstable. For charged clusters that were formed by ion-induced nucleation, we were able to measure, for the first time, their progressive neutralization due to recombination with oppositely charged ions. A large fraction of the clusters carried a charge at 1.2 nm diameter. However, depending on particle growth rates and ion concentrations, charged clusters were largely neutralized by ion–ion recombination before they grew to 2.2 nm. At this size, more than 90 % of particles were neutral. In other words, particles may originate from ion-induced nucleation, although they are neutral upon detection at diameters larger than 2.2 nm. Observations at Hyytiälä, Finland, showed lower ion concentrations and a lower contribution of ion-induced nucleation than measured at CLOUD under similar conditions. Although this can be partly explained by the observation that ion-induced fractions decrease towards lower ion concentrations, further investigations are needed to resolve the origin of the discrepancy.