669 research outputs found
A study of infant mortality from linked records by age of mother, total-birth order, and other variables; United States, 1960 live-birth cohort
No full textInfant mortality in the United States, based on a cohort study for infants born alive during 1960, related to age of mother, total-birth order of infant, and other characteristics reported on birth or death records; considers color, sex, and age at death of infants who died during the first year of life.[by Helen M. Vavra and Linda J. Querec]Includes bibliographical references
Theoretical investigations of the properties of oblique detonation waves
No full textIncludes supplementary materialOne method of solving the problem of burning or combustion at supersonic speed is by combusting in a stationary detonation wave. Stabilization of a detonation wave has been recently accomplished and is reproducible, but only in laboratory type apparatus. Using two-dimensional steady flow, perfect gas theory, this paper provides solutions for the changes in properties that may be expected across any oblique detonation wave. Equation are established and solved using the Control Data Corporation 1604 digital computer of the U.S. Naval Postgraduate School, Monterey, California, fordifferent values of specific heat ratio, initial Mach number, a function of the flow deflection angle, and the amount of heat added in the detonation. The results appear in tabular form and for several specific values of Mach number and heat addition in graphical form. An example of use of the data is shown with reference to a ramjet engine operating with a stationary detonation wave for the combustion process. The author wishes to express his sincere appreciation to Professor Michael H. Vavra for his encouragement, supervision, and patience during the period of this work.Approved for public release; distribution is unlimited.Lieutenant, United States Navyhttp://www.archive.org/details/theoreticalinv00gib
Helquat-induced chiroselective aggregation of Au NPs
No full textAu nanoparticles (NPs) are functionalized with chiral (R) or (S) binaphthol phenylboronic acid ligands, (1a) or (1b). The (R)- or (S)-binaphthol phenylboronic acid ligands form donor-acceptor complexes with the chiral dicationic helicene, helquat (P)-HQ2+ or (M)-HQ2+, (2a) or (2b). The association constants between (1a)/(2a) and (1a)/(2b) correspond to (7.0 ± 0.5) × 105 M-1 and (2.5 ± 0.3) × 105 M-1, respectively, whereas the association constants between (1b)/(2b) and (1b)/(2a) correspond to (4.0 ± 0.5) × 105 M-1 and (1.8 ± 0.3) × 10 5 M-1, respectively. Chiroselective aggregation of chiral binaphthol phenylboronic acid-capped Au NPs triggered by the chiral helquats, is demonstrated. © 2012 American Chemical Society
Candonopsis falklandica Vavra 1898
No full textCandonopsis falklandica Vávra, 1898 Listed in: Ringulet (1955); Smith and Sayers (1971). Recorded from: freshwater lakes and/or pools. Location: Falkland Is. Family CYPRIDIDAE Baird, 1845 5 Cypridae of authors sensu Bowman and Abele (1982).Published as part of Pugh, P. J. A., Dartnall, H. J. G. & McInnes, S. J., 2002, The non-marine Crustacea of Antarctica and the Islands of the Southern Ocean: biodiversity and biogeography, pp. 1047-1103 in Journal of Natural History 36 (9) on page 1067, DOI: 10.1080/00222930110039602, http://zenodo.org/record/530099
Ecosystem services of urban agriculture: Perceptions of project leaders, stakeholders and the general public
No full textWithin the scholarly debate, Urban Agriculture (UA) has been widely acknowledged to provide diverse environmental and socio-cultural ecosystem services (ESs) for cities. However, the question of whether these potential benefits are also recognized as such by the involved societal groups on the ground has not yet been investigated. This paper aims at (1) assessing the perceived ESs of UA, comparing the views of different societal groups in the city of Bologna, Italy (namely: UA project leaders, stakeholders and the general public) and (2) to identify differences in the evaluation of specific UA types (indoor farming, high-tech greenhouses, peri-urban farms, community-supported agriculture, community rooftop garden and urban co-op). In total, 406 individuals evaluated 25 ESs via a standardized Likert-scale survey. The study unveiled similarities and divergences of perceptions among the different societal groups. The statistical analysis indicated that the general public and UA stakeholders agree on the high relevance of socio-cultural ESs, while provisioning ESs was considered as less significant. UA types focusing on social innovation were expected to provide higher socio-cultural ESs whereas peri-urban activities were more closely linked to habitat ESs. We assume that involvement and knowledge of UA are determining factors for valuing the provision of ESs through UA, which needs to be considered for ES valuation, particularly in a policymaking context
Strandesia mercatorum Vavra 1895
No full textStrandesia mercatorum (Vavra, 1895) (Figs 13 –18, 20) Cypris (Strandesia) mercatorum Vavra, 1895: 18 Strandesia mercatorum (Vavra, 1895) — Müller, 1912: 187. Material examined. Type material, c. 30 males and females in EtOH, Zanzibar, Africa; collected by F. Stuhlmann, 2 May 1888) (Zoologisches Institut und Zoologisches Museum, Hamburg). Lectotype (here designated): a male, with soft parts dissected in glycerine in a sealed slide, and valves stored dry in a micropalaeontological slide. (ZIZM-K 19115 C) Additional material examined: c. 25 males and females in a sample from C.S.I.R. water research (GEN 568 D), collected from Dambo pan, Mozambique, 30 June 1960. Measurements (in μ m). Female: LV (n= 3), L = 1970, H = 1050; RV (n= 3), L = 1910, H = 1150; W = 1020. Male: LV (n= 1), L = 1810, H = 978; RV (n= 1), L = 1720, H = 1040; W = 824. Diagnosis. Carapace laterally elongated with height c. half the length. RV mid-dorsally with fin-shaped protuberance (anterior end blunt, posterior end pointed), somewhat curved outwardly. Valve surface set with small shallow pits and short setae. LV border slightly swollen and with small hollow channel inside along anterior, ventral and posterior margins; anterior part with broad margin, without inner list. RV with selvage along valve margin. Caudal ramus slender, ventral margin set with 4 groups of finely serrated spines; proximal and distal claws denticulated, set with 2 groups of spines. Hemipenis with medial shield rounded; lateral shield large, wing-like; lateral, finger-like protuberance. Description of female. Carapace in lateral view (Fig 13 D–E) elongated, with rounded anterior and posterior margins, length c. twice the height; greatest height situated at one-third of length. Surface set with small shallow pits and short setae (Fig 14 I–J). Carapace in dorsal view (Fig 13 F) egg-shaped, with bluntly pointed anterior and posterior edges, slightly rostrum-like anteriorly; protuberance on RV concave at the middle of inner margin, forming a half circle; greatest width c. half of length; LV overlapping RV anteriorly, posteriorly and ventrally. Carapace in ventral view (Fig 13 G) with LV overlapping RV and with slightly protruding valve margin at the middle of carapace. Outer list on RV margin narrow, no outer list on LV. LV in inner view (Fig 14 A, E–F) dorsally straight over c. one-third of the length, sloping down to the rounded anterior and posterior margins; ventral margin slightly sinuous in the anterior half; anterior margin broadly rounded. Valve border slightly swollen, with unequal, hollow channel inside (Fig 20), anteriorly larger, ventrally small and narrow and posteriorly medium-size. A continuous groove situated along anterior, ventral and posterior margins. Calcified inner lamella descending into the cavity of the valve, anteriorly wide, without inner list, posteriorly narrower. RV in inner view (Fig 14 B, G–H) with both anterior and posterior margins rounded, dorsally with finshape protuberance, anterior end of protuberance sloping, posterior end spine-like; the protuberance somewhat curved outwardly, shape variable, higher or lower, with stronger or weaker posterior spine, in some specimens with rounded edges; selvage set along anterior, ventral and posterior margins; calcified inner lamella narrow, anteriorly wider than posteriorly; anteroventral margin with flange. Muscle scars as in Fig 14 K. A 1 (Fig 15 A): first segment with 3 setae (1 short subapical seta, 2 long apical setae) and a small, unsegmented, tube-like proximal Wouters organ (Fig 15 C–D). Second segment wider than long, with 1 short apical seta and small, short, unsegmented, subapical Rome organ (Fig 15 B). Third segment bearing 2 short setae (the longer one as long as fourth segment). Fourth segment with 2 short and 2 long setae. Fifth segment with 1 short (reaching beyond the terminal segment) and 3 long setae. Sixth segment with 4 long setae. Terminal segment apically bearing aesthetasc ya and 3 setae, 2 long and 1 short, the latter approximately twothirds of the length of ya. A 2 (Fig 15 E–F) with penultimate segment undivided. Exopodite with 2 short and 1 long (reaching distal end of first endopodite) setae. First segment of endopodite with 5 + 1 natatory setae, the shortest one c. half of penultimate segment, the 5 remaining setae long, reaching beyond the end claws of the last two segments; aesthetasc Y short, but with a long terminal part. Penultimate segment undivided, with distally 3 serrated claws and with aesthetasc y 2 c. half the length of the terminal segment; z 1 –z 3 setae long; medially with 2 (1 long, 1 shorter (c. two-thirds of the long one)) anterior setae and 4 posterior setae (t 1 –t 4). Terminal segments (Fig 15 F) with 2 serrated claws, a g-seta and an aesthetasc y 3, the latter about as long as the accompanying seta. Md (Fig 15 H–I): first segment of palp with a large respiratory plate, 2 subapical setae (s 1 and s 2), a long seta and relatively long, slender, unsegmented and smooth α-seta. Second segment dorsally with a group of 3 (2 long, 1 short) apical setae, ventrally with a stout, plumose, cone-shape, subapical β-seta, surrounded by 3 hirsute and 1 long bald setae. Penultimate segment with 3 groups of setae; dorsally with a subapical group of 3 long and 1 shorter setae, laterally with 1 stout, long and hirsute, apical γ-seta and 3 smooth subapical setae, ventrally with 1 long and 1 short (c. half of terminal segment) setae. Terminal segment apically with 3 shorter setae and 3 claws, the latter weakly set with setulae. Rake-like organ (Fig 15 L) stout, solid and T-shape, with c. 10 blunt teeth. Mx 1 (Fig 16 A) comprising a large respiratory plate (Fig 17 A), 3 endites and a 2 -segmented palp. Basal segment of palp with an apical group of 5 long setae and 2 (1 long, 1 short) subapical setae. Terminal palpsegment elongated and with 3 claws and 3 setae, the former weakly sclerified. Third endite with 2 large bristles, apically serrated and with c. 8 other setae. Sideways-directed bristles on first endite subequal. T 1 (Fig 16 B–C) with 2 short a-setae and long b- and d-setae, apically with a group of 14 hirsute, unequal setae. Endopodite a weakly built palp with 3 unequal apical setae. Exopodite a respiratory plate, with 5 + 1 hirsute setae. T 2 (Fig 16 D–E) with seta d 2 c. half the length of seta d 1. Second segment with 1 long apical seta (c. half of penultimate segment). Penultimate segment medially divided into a- and b-segments, the former with 1 long apical seta, the latter with a pair (1 long, 1 spine-like) of apical setae. Terminal segment with an apical, serrated claw and 2 (1 subapical, 1 apical) long setae (length c. one-fourth of claw). T 3 (Fig 16 F–G) a cleaning limb. First segment with 3 long setae. Second segment with 1 apical seta. Third segment undivided, with medially 1 lateral seta. Terminal segment with an apical pincer and 1 reflexed subapical seta. Caudal ramus (Fig 16 I) slender, rather straight and set with 4 groups of fine spines on the ventral margin; claws (Fig 16 J) straight, set with 2 groups of fine spines (c. two-thirds of their length); distal claw c. one-third of ramus; proximal claw slightly more than half of distal claw; distal end of both claws slightly curved; distal seta hirsute, short (c. half of distal claw). Attachment of the caudal ramus (Fig 16 H) slim and with Triebel’s loop situated in the main branch; dorsal branch elongated, thin; ventral branch elongated, with distally swollen end. Description of male. Carapace and valves (Fig 13 H–J, Fig 14 C–D) as in the female, generally somewhat smaller. All limbs as in the female, except for T 1 (Figs 17 B,C) and the last two segments of A 2 (Fig 15 G) with sexual dimorphism. Setae z 1 and z 2 of the penultimate segment of A 2 transformed to claws; claws G 1 and G 3 reduced, the former short, the latter seta-like; Gm on terminal segment of A 2 reduced, appearing smaller and shorter (c. 50 % of GM); y 3 and g-seta different in length between male and female, y 3 in male shorter (c. half the length of GM claw) than that of female (c. two-thirds of the length of GM claw), g-seta in male shorter (less than half the length of GM claw) than that of female (c. slightly more than half the length of GM claw). T 1 with asymmetrical prehensile palps (endopodite forming prehensile palp); right prehensile palp (Fig 17 C) anteriorly with large triangular lobe and 2 apical spines; left palp (Fig 17 B) bearing elongated, curved lobe, 1 apical spine and a group of small tubercles. Zenker’s organ (Fig 17 F, 18 C–I) elongated, length c. 3.2 times the width, set with c. 27 chitinous spiny whorls, distal end set with crowns of petal-like structure encircled by a cone-shaped chitinous sheet, proximal end set with a bunch of hirsute filaments encircled by a cone-shaped chitinous sheet. Hemipenis (Fig 16 D–E, 18 A–B) relatively large; medial shield rounded; lateral shield large, distal end forming a narrow wing; lateral side with finger-like protuberance. Proximal connected bases of hemipenes with a symmetrical penile attachment. Middle of hemipenis with 1 loop of the postlabyrinthal spermiduct.Published as part of Savatenalinton, Sukonthip & Martens, Koen, 2009, Redescription of the type species of Strandesia Stuhlmann, 1888 and Cypricercus Sars, 1895 (Crustacea, Ostracoda, Cypricercinae), with a description of a new species of Cypricercus from South Africa, pp. 1-42 in Zootaxa 2007 on pages 21-29, DOI: 10.5281/zenodo.18570
Single-electron transport and magnetic properties of Fe-SiO2 nanocomposites prepared by ion implantation
No full textThe electric transport, magnetic, and magnetotransport properties of Fe-SiO2 nanocomposites prepared by Fe-ion implantation into silica were investigated. The structural studies revealed bcc Fe nanoparticles of an average size of 3 nm dispersed in a 100-nm-thick nanocomposite layer formed within the silica substrate. Using special thin-film electrodes that were only 100 nm apart, in-plane electrical measurements were performed in a temperature range of 4-300 K. Though no external gate electrode was used, single-electron transport phenomena (Coulomb blockade and Coulomb staircase) were observed at 4 K. The presence of Coulomb steps in I-V curves implies that the electric transport was realized by the tunneling of electrons via a random quasi-one-dimensional chain of a few isolated iron nanoparticles. The magnetic properties of the nanoparticles were determined by surface effects and by the superparamagnetic behavior. The nanoparticles exhibited enhanced anisotropy and were dipolarly interacting. However, the tunneling current was found to be independent of external magnetic field; i.e., no tunneling magnetoresistivity (TMR) was measured at 77 K. At this temperature the nanoparticles were superparamagnetic. Presumably, a low volumetric concentration of Fe nanoparticles (< 14%) and a spin-flip process due to residual single Fe atoms present in the silica barriers were responsible for the absence of the TMR effect
Acocypris Vavra 1895
No full textAcocypris Vávra, 1895 Acocypris acuminata Rome, 1962: AT Acocypris angulosa (Daday, 1910) Martens 1984: AT Eucypris angulosa Daday, 1910 * Acocypris capillata (Vávra, 1895) G.W. Müller 1898: AT Cypris capillata Vávra, 1895 Syn.: Parastenocypris unispinosa Onyedineke, 2000 (fide Martens 2001a) Acocypris hirsuta Rome, 1965: AT Acocypris hyalina Lowndes, 1931: AT Acocypris longiuscula Rome, 1965: AT Acocypris platybasis (Lowndes, 1932) Martens 1984: AT Stenocypris platybasis Lowndes, 1932 Acocypris stenocyproides Klie, 1938: ATPublished as part of Meisch, Claude, Smith, Robin J. & Martens, Koen, 2019, A subjective global checklist of the extant non-marine Ostracoda (Crustacea), pp. 1-135 in European Journal of Taxonomy 492 on page 24, DOI: 10.5852/ejt.2019.492, http://zenodo.org/record/327109
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