1,858 research outputs found
Waxiella DE LOTTO
No full textWAXIELLA DE LOTTO Waxiella De Lotto, 1971: 148. Waxiella De Lotto; De Lotto (1971); Ben-Dov (1986); Hodgson (1994). Type species: Ceroplastes subdenudatus Newstead, by original designation.Published as part of Hodgson, Chris J. & Peronti, Ana L. B. G., 2012, 3372, pp. 1-265 in Zootaxa 3372 on page 19
High-energy cosmic rays
No full textIn the past few years significant progress has been made towards identifying and understanding cosmic particle accelerators. Nevertheless some critical, long-standing questions remain unanswered, and the field is as active as ever. I review recent experimental results on high-energy (HE, > 1015 eV) cosmic rays (CR). I will focus on direct CR electron and positron measurements and indirect ultra-HE (> 1018 eV) CR measurements, and on Very-HE (> 100 GeV) gamma ray detections. Open questions and prospects are addressed, and proposed and upcoming experiments are outlined
Interconnection phenomena in W pair production at LEP2
No full textIn this paper the status of the experimental analysis on interconnection effects between W pairs hadronically decaying at LEP 2 is reviewed. (9 refs)
Interconnection phenomena in W pair production at DELPHI
No full textInteractions between the products of the hadronic decays of different Ws in WW pair events can occur at several stages: from the colour rearrangement between the quarks coming from the primary branching, to the gluon exchange during the parton cascade, to the mixing of identical pions due to Bose-Einstein correlations. Besides the intrinsic interest of their study related to the understanding of the multiparticle production mechanisms, these phenomena can affect the ultimate accuracy in the W mass measurement by LEP 2. The status of the DELPHI experimental analysis on interconnection effects between W pairs hadronically decaying is reviewed in this paper. (3 refs)
Procedurally Fair and Stable Matching
No full textWe motivate procedural fairness for matching mechanisms and study two procedurally fair and stable mechanisms: employment by lotto (Aldershof et al., 1999) and the random order mechanism (Roth and Vande Vate, 1990, Ma, 1996). For both mechanisms we give various examples of probability distributions on the set of stable matchings and discuss properties that differentiate employment by lotto and the random order mechanism. Finally, we consider an adjustment of the random order mechanism, the equitable random order mechanism, that combines aspects of procedural and "endstate'' fairness. Aldershof et al. (1999) and Ma (1996) that exist on the probability distribution induced by both mechanisms. Finally, we consider an adjustment of the random order mechanism, the equitable random order mechanism.procedural fairness, random mechanism, stability, two-sided matching
Ceroplastes rufus De Lotto
No full textCeroplastes rufus De Lotto (Fig. 50; Map fig. 104) Ceroplastes rufus De Lotto, 1966: 143. Cerostegia rufa (De Lotto); De Lotto, 1969b: 215. Material examined: Paratype ♀: South Africa, Western Cape Province, Bitterfontein, on Ruschia (spelt Rhushia) sp., 18.ii.1965, J.H. Giliomee (BMNH): 2/2 (good but only very young adult females available). Also seen 2 slides with single specimens present in USNM (good). Note. Data in brackets from De Lotto, 1966. Unmounted material. “Test of young adult female rounded, low convex, with dorsal and lateral plates poorly marked; colour reddish brown with a large elongate opaque white boss on the centre of the dorsum; wax very soft.” (De Lotto, 1966: 143). Mounted material. Body of young adult females broadly oval with rather marked clefts; without dorsal processes. Caudal process apparently quite large and extending dorso-posteriorly but mainly only lightly sclerotised; process unusual, with anal lobes near apex of caudal process (see figure). Body length 1.5–1.67 (1.4–1.8) mm, width 1.07 mm. Dorsum. Derm entirely membranous on young individuals, except for a small area of sclerotisation around anal plates. Caudal process also mainly membranous, area of sclerotisation 235–280 µm long, 170–175 µm wide; dorsally, sclerotisation surrounded by a large clear area without dorsal pores or setae. Derm with 6 further clear areas: anterior, medio-dorsal and 1 above each stigmatic cleft; posterior abdominal clear areas apparently absent; each clear area with 1 or 2 dorsal setae. Dorsal setae rather variable in shape, mostly rather pointed but some shorter and more blunter; each about 3–5 µm long, subequal to or slightly longer than width of basal socket (basal socket about 3.5–4.5 µm wide); frequent throughout except scarce in clear areas. Dorsal pores: (i) loculate microducts of complex type, each about 3–5 µm wide, with mainly 1 or 2 small satellite loculi, but pores with 3 loculi quite frequent; frequent throughout but absent from all clear areas; also present on ventral surface of anal process; wax-plate lines not detected; and (ii) simple microducts, rather abundant in all clear areas but not detected elsewhere. Preopercular pores: about 20 pores present in a broad transverse band about 2–3 pores wide, extending along entire anterior margin of anal plates. Anal plates each 153–158 (145–190) µm long, combined width 125 µm; each with 2 or 3 long dorsal setae on posterior quarter of each plate, each 45–80 µm long, plus a shorter setose seta on apex, about 35 µm long. Anal tube short, subequal to length of anal plates or shorter; anal ring setae each about 130–135 µm long. Margin. Marginal setae intermingled amongst roundly conical stigmatic setae which extend around most of margin; each marginal seta setose, 11–13 µm long; with 6–9 anteriorly between eyespots; 0–2 between eyespots and anterior stigmatic setae, 0 or 1 on each side between stigmatic clefts and about 12–17 on each side of abdomen, mainly along posterior margin where conical stigmatic setae mainly absent; margin also extending from venter along ventral surface of caudal process, each side with 6–11 marginal setae, mostly rather larger than elsewhere, up to 25 µm long; anal lobe setae apparently present on apex of caudal process, each 27–35 µm long. Stigmatic clefts quite deep, each with a group of stigmatic setae about 3–5 setae deep in each cleft but narrowing to 1–2 setae deep along most of rest of margin [De Lotto, 1966, p. 144 shows the marginal band as being up to perhaps 3 setae wide]; those along margin mainly quite small (about 5–7 µm long, 4–5 µm wide at base) but with a few rather larger setae slightly displaced onto dorsum (each about 9 µm long, 7.5 µm wide at base); each cleft with up to 10 even larger setae; all stigmatic setae either roundly conical or with a slightly flattened apex; frequency impossible to count but with 30–34 small and 2–7 larger setae between eyespots; totals perhaps about 180 per side; stigmatic setae absent from posteriormost part of margin. Eyespots rather small and inconspicuous, each about 17–20 µm wide. Venter. Derm entirely membranous in young specimens. Pregenital disc-pores present around vulva and across preceding segment, and then with 1–3 medially and 5–13 associated with anogenital fold in segment V plus 1 medially in IV; none on thorax. Spiracular disc-pores in broad bands about as wide as peritreme; with none more medially. Ventral microducts absent medially on abdominal segments V–VII. Ventral tubular ducts, each with a short bulbous inner ductule, present in a sparse group of 10–24 anterior to antennae and in a very sparse submarginal band (1 or 2 laterally on head, 1–8 on thorax and several laterally on abdomen); most abundant posteriorly associated with anogenital fold where frequent (probably at least 10–14 on each side); absent medially. Submarginal setae much more frequent than marginal setae. Antennae each with 8 (7 or 8) segments but segmentation often obscure; segment III with 2 pseudo-articulations; total length 175–200 (170–190) µm. Clypeolabral shield about 165 µm long. Spiracular peritremes each 58–60 µm wide; muscle plate very short. Legs much reduced but generally with all 5 segments visible although tibia and tarsus often fused; without a tibio-tarsal articulation and sclerosis; total length of metathoracic legs 140–145 µm; tarsal digitules 21–25 µm long, probably not capitate; claw digitules both narrow, with very small capitate apices, each about 17 µm long; claws all very short, without a denticle. Discussion: C. rufus De Lotto is rather unlike any other Ceroplastes species known from Africa. De Lotto (1966) suggested that this species is close to C. rubens (Maskell) but it is not clear why he thought this. Although the available specimens were very young, they were unique in having the following combination of characters: (i) roundly convex stigmatic setae extending around most of the margin, mainly in a double band, the more dorsal setae largest (C. singularis Newstead also has stigmatic setae all around margin but they are more sharply pointed and not in this arrangement); (ii) ventral tubular ducts in a sparse submarginal band (De Lotto (1966) stated that their frequency varied greatly between specimens); submarginal bands of tubular ducts are also found in C. deceptrix, C. madagascariensis, and C. rusticus; (iii) the shape and structure of the anal process – with a small area of sclerotisation (but which might be much larger in older specimens), and with the body margin extending to the apex of the anal process; (iv) only 6 dorsal clear areas; (v) very reduced legs (also known in C. brevicauda, C. destructor, C. luteolus, C. reunionensis and C. rubens), (vi) rather pointed dorsal setae, and (vii) 7- or 8-segmented antennae (although some other specimens might not have complete pseudoarticulations and thus appear 6 segmented). At the present time, C. rufus is only known from Cape Province, South Africa, on Ruschia sp. (Aizoaceae).Published as part of Hodgson, Chris J. & Peronti, Ana L. B. G., 2012, 3372, pp. 1-265 in Zootaxa 3372 on pages 96-9
Ceroplastes stenocephalus De Lotto. As 1961
No full text<i>Ceroplastes stenocephalus</i> De Lotto <p>(Fig. 72; Map fig. 105)</p> <p> <i>Ceroplastes stenocephalus</i> De Lotto, 1961: 320.</p> <p> <i>Gascardia stenocephala</i> (De Lotto); De Lotto, 1965: 206.</p> <p> <b>Material examined:</b> <b>Paratype</b> ♀, <b>Kenya,</b> Magadi, 6.x.1957, <i>Acacia</i> sp., G. De Lotto (BMNH): 2/2 (good).</p> <p> <b>Note</b>. Data given in brackets from De Lotto (1961).</p> <p> <b>Unmounted material</b>. "Tests crowded and fused together so as to form an indistinct mass of creamy-yellow wax, suffused with a pinkish tinge; wax rather hard." (De Lotto, 1961: 320).</p> <p> <b>Mounted material</b>. Body roundly oval and convex, with distinct, quite deep, stigmatic clefts; dorsum without lateral tubercles. Caudal process large but probably not very convex, set almost medially on dorsum. Body length 2.2–2.25 (1.9–2.5) mm, width across abdomen 2.07–2.08 (1.8–2.4) mm; caudal process 0.87–1.0 mm long and 1.17–1.23 mm wide.</p> <p> <b>Dorsum</b>. Derm membranous except for caudal process which is heavily sclerotised; without obvious clear areas but dorsal setae and loculate microducts sparse where these areas would be expected. Dorsal setae each sharply spinose, length at least twice width of basal socket, length 10–15 µm; basal socket width 5–7 µm; present sparsely throughout. Dorsal pores: (i) loculate microducts of complex type, each with 1–4 satellite loculi; those with 3 satellite loculi most abundant, each about 4–5 µm wide, generally clearly smaller than width of basal socket of dorsal setae; those with 2 loculi significantly less frequent; those with 1 satellite loculus only occasional and those with 4 loculi rare; microducts frequent throughout but each “clear area” with a sparse covering of pores with 1 or no satellite loculi; wax-plate lines not detected; and (ii) simple microducts with sclerotised pore about 1–2 µm wide, with a similar distribution to loculate microducts but also present very sparsely along margins. Preopercular pores: 24 or 25 present in a narrow transverse band about 2–3 pores deep. Anal plates together rather rounded; length of plates 150 (150–175) µm, combined widths 170 µm; each with 3 long dorsal setae, that nearest outer margin about 110 µm long; apical setae all missing. Anogenital fold with 9 setae along anterior margin, longest laterally, about 30 µm long; and with 1 shorter seta on each lateral margin ventrally. Anal tube very short, only about 2/3rds length of anal plates; anal ring setae each about 115 µm long.</p> <p> <b>Margin</b>. Marginal setae stoutly setose, each about 17–23 µm long; present in a broad, sparse band except in stigmatic clefts; some clefts have 1 or more much larger, more spinose, marginal setae, up to about 35 µm long; each anal lobe with 1–3 slightly longer setae, longest about 35 µm long. Stigmatic clefts quite deep, each with a compact group of rather narrow, sharply-conical setae extending in a broad group onto dorsum; each group with about 100 (80–110) setae, all similar in size, each 13–20 µm long and 7.5–9 µm wide at base, pointed, with rather straight sides. Eyespots each about 25 µm wide.</p> <p> <b>Venter</b>. Derm entirely membranous. Pregenital disc-pores abundant around genital opening (segment VII) and across segments VI and V, plus 1 or more generally present medially on IV and III; absent more anteriorly. Spiracular disc-pores each mainly with 5 loculi but those nearest margin larger with more loculi; present in bands of about 75 pores, each band sparse and narrow near spiracles but broadening and pores becoming denser near margin; with a few extending medially past peritreme, which tend to have more loculi. Ventral microducts showing nothing distinctive. Ventral tubular ducts absent in cephalic region; anogenital region covered by sclerotised caudal process and so presence hard to determine but 1 duct definitely located, with outer ductule about 10–12 µm long, associated with anogenital fold between segments V and VI. Submarginal setae each 14–17 µm long, set some distance in from margin.</p> <p>Antennae each with 7 or 8 segments, when 7, generally with pseudo-articulations in segment IV; total length 295–325 (300–335) µm. Clypeolabral shield about 175–185 µm long. Spiracles: width of peritremes 50–60 µm. Legs well developed, each with a distinct tibio-tarsal sclerosis; each claw with hint of a denticle; claw digitules both broad and subequal to or slightly longer than tarsal digitules; dimensions of metathoracic legs (µm): coxa 150–157; trochanter + femur 195–200 (180–220); tibia 145–157; tarsus 100–105 (tibia + tarsus 230–250), and claw 33.</p> <p> <b>Discussion</b>. The adult female of <i>C. stenocephalus</i> is very distinctive, with the broad group of densely packed, narrow, sharply-conical setae in each stigmatic cleft. Other diagnostic characters are: (i) the size and position of the caudal process; (ii) the absence of clear areas on the dorsum; (iii) dorsal setae quite large and sharply-spinose; (iv) antennae 7 or 8 segmented; (v) loculate microducts smaller than width of basal socket of dorsal setae, and (v) ventral tubular ducts absent from cephalic region.</p> <p>This description differs slightly from the original description (De Lotto's (1961) characters in brackets) in having: (i) dorsal pores with 1–4 satellite loculi (only 2 or 3); (ii) some antennae apparently 8 segmented (7 segmented); (iii) ventral tubular ducts at least sometimes present on the abdomen (absent), and (iv) claws with a hint of a denticle (absent in figure).</p> <p> <i>C. stenocephalus</i> is only known from the original collection from Kenya on <i>Acacia</i> sp. (Fabaceae).</p>Published as part of <i>Hodgson, Chris J. & Peronti, Ana L. B. G., 2012, 3372, pp. 1-265 in Zootaxa 3372</i> on pages 159-16
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