188,292 research outputs found
Gastromyzon ingeri Tan 2006
No full textGastromyzon ingeri Tan Remarks. A common species of Gastromyzon found in riffles of forested streams and rivers. The live colouration of this species has not been documented previously (see Tan, 2006). Living fish having a brownish-yellow body colouration, turquoise sheen over body dorsum, with gold highlights on every dorsal and lateral body scale; eye with a thin gold iris; dorsal fin hyaline with 2–3 rows of black spots; pectoral and pelvic fins brownish-yellow; anal fin hyaline; base of caudal peduncle and fin is grey, caudal fin is light-blue with up to 5 rows of black spots (Fig. 7).Published as part of Wilkinson, Clare L. & Hui, Tan Heok, 2018, Fishes of the Brantian drainage, Sabah, Malaysia, with description of a new Rasbora species (Teleostei: Cyprinidae), pp. 595-609 in Raffles Bulletin of Zoology 66 on page 601, DOI: 10.5281/zenodo.536011
Additions to the moss flora of Endau Rompin National Park, Johore State, peninsular Malaysia
No full textIn a recent survey of the Endau Rompin National Park (ERNP) in Johore State, 81 species and 4 varieties of mosses were documented. This increases the previous count from 62 species and 3 varieties of mosses in ERNP to 111 species and 5 varieties in total. Of these, 30 species are new records for Johore State. Rhaphidostichum bunodicarpum and Trichosteleum stigmosum are two species new to Peninsular Malaysia. Thuidium assimile is a new record for West Malesia. A new combination, Papillidiopsis aquaticum (Dix.) Boon-Chuan Ho & B.C. Tan is proposed. In terms of species composition, the pan-tropical families of Calymperaceae, Fissidentaceae, Leucobryaceae and Sematophyllaceae predominate the moss flora of ERNP
Analysis of aluminium sensitivity in sorghum (Sorghum bicolor (L.) Moench) genotypes.
No full textTwelve genotypes of sorghum ( Sorghum bicolor (L.) Moench) differing in Al sensitivity were grown in an acid soil (with additions of lime or MgSO <sub>4</sub> ) and in nutrient solutions (with or without Al at constant pH) for periods between 14 and 35 days. The objective was the identification of the factors controlling dry matter yield of sorghum under different growth conditions. In both media Al was the major constraint, restricting growth in two independent ways: (1) by inducing Mg deficiency and (2) via damaging the roots ( i.e. by giving them a stubby and discolorated appearance and by reducing their specific root length, m g <sup>-1</SUP>dry root). The sensitivities of the genotypes against Al-induced Mg deficiency and Al-induced root damage were not correlated. At moderate acidity (pH around 4.8), Mg deficiency dominantly limited growth whilst at a higher acidity (pH ~4.2) root damage overruled Mg deficiency in its negative effect on growth. At pH 4.8, addition of Mg improved growth by reducing the degree of Mg deficiency. At pH 4.2, Mg improved growth mainly by preventing the roots from Al- induced damage.Several external factors modified the AI sensitivity of the genotypes by strengthening or weakening the negative effects of Al on Mg nutrition and root development. At pH 4.2, Ca and NH <sub>4</sub> both counteracted AI-induced root damage but aggravated Al-induced Mg deficiency. The contrary was true for NO <sub>3</sub> . When the concentration of soluble Al was kept approximately constant at 15 μM, both Al-induced root damage and Mg deficiency were aggravated by acidity in the range pH 3.9-4.8. Aluminium toxicity in sorghum grown in nutrient solution was independent of P deficiency, although an increased P supply partly eliminated Al phytotoxicity.The results stress the importance of both Al and Mg ions and their interactions in determining growth response of sorghum and other cereals to acid soils
Total synthesis of TAN-1057 and analogues
No full text1997 Spring.Includes bibliographical references.Part I. An asymmetric and stereochemically unambiguous construction of diaminopimelic acid and related system using the chiral, non-racemic diphenyl oxazinones glycinate templates has been developed. The preparations of (R,R)-DAP, (S,S)-DAP, (S,S)-2,7-diaminosuberic acid, and mono-N-protected (S,R)-DAP are described. The synthesis of γ-D(L)-glutamyl-L-meso-diaminopimelic acid dipeptide, a subunit of both FK-156 and FK-565, is also described. The availability of both optical antipodes of the glycinate templates renders this chemistry adaptable to prepare all possible diastereoisomers of substances based on the DAP skeleton in optically pure form.Part II. The first total synthesis of anti-MRSA dipeptides TAN-1057 A~D has been achieved. A new efficient method for preparation of amidinoureas has been developed and successfully applied to the total synthesis of TAN-1057. More importantly, this concise total synthesis paves the way for access to analogues that are not available from natural sources. Eight new analogues of TAN-1057 were designed, synthesized and assayed against MRSA. A new synthetic analogue 102 (CY-1800) showed very similar activity to that of TAN-1057. Other analogues prepared showed weak or no activity against Staphylococcus aureus up to 1 mg/mL. The success on discovery of a new potent anti-MRSA analogue proved the usefulness of this highly flexible strategy for the development of better analogues than the natural ones for the potential use as antibiotics
Lobocheilos aurolineatus Ciccotto & Tan 2018, sp. n.
No full textLobocheilos aurolineatus Ciccotto and Tan, sp. n. Figs. 1–2, Table 1 ? Tylognathus hispidus (non Valenciennes, in Cuvier & Valenciennes 1844): Vaillant 1902: 108; and Popta 1906: 108.? Lobocheilus hispidus (non Valenciennes, in Cuvier & Valenciennes 1844): Christensen 1992: 600.? Lobocheilos kajanensis (Popta 1904): Kottelat 1995: 404. Holotype. MZB 17222, 55.6 mm SL; Indonesia: Borneo: East Kalimantan: Mahakam River at Kota Bangum, 0°16.02’S 116°35.16’E; H.H. Tan & D. Wowor, 7–9 Nov 1999. Paratypes. MZB 17223, 5, 52.9–59.1 mm SL; Indonesia: Borneo: East Kalimantan: Mahakam basin, Lake Jempang, 0°25.29’S 116°15.78’E; H.H. Tan and D. Wowor, 9 Nov 1999; UF 191478, 2, 55.7–58.7 mm SL, same data as MZB 17223; ZRC 54764, 4, 48.9–54.9 mm SL, same data as MZB 17222; ZRC 54765, 5, 53.2–59.9 mm SL, same data as MZB 17223. Other material. ZRC 51577, 17, 39.8–55.6 mm SL; Indonesia: Borneo: East Kalimantan: Aquarium trade; ZRC 54745, 7, 36.3–42.5 mm SL; Indonesia: Borneo: East Kalimantan: Balikpapan, aquarium trade. Diagnosis. A member of Lobocheilos as diagnosed by Kottelat & Tan (2008). Lobocheilos aurolineatus is differentiated from all other members of the genus except for L. ixocheilos Kottelat & Tan and L. tenura Kottelat & Tan in possessing a single, broad black midlateral stripe extending from the operculum to the caudal-fin base. Lobocheilos aurolineatus differs from L. ixocheilos and L. tenura in possessing a thin cream to yellow stripe on the anterior ¾ of the flank, separating the midlateral stripe from the brown dorso-lateral scales (vs. stripe absent in L. ixocheilos and L. tenura; Fig. 3) and a small mouth width (23.5–29.9% HL in L. aurolineatus vs. 32.1–45.0% and 34.4–46.4% HL in L. ixocheilos and L. tenura, respectively). Description. Morphometric and variable meristic data presented in Table 1. Dorsal profile of head and body continuous; body deepest at dorsal-fin origin. Ventral profile from tip of snout to anal fin slightly rounded. Snout conical. Head short, longer than wide. Eyes lateral. Dorsal-fin origin anterior of pelvic-fin origin. Pectoral fin pointed, positioned ventrally, reaching ¾ distance between pectoral-fin origin and pelvic-fin origin when adpressed. Pelvic fin pointed, concave, reaching anus when adpressed. Anal fin reaching ¼ distance to base of caudal fin when adpressed. Dorsal and anal fins slightly concave. Caudal fin deeply forked with pointed lobes, approximately equal in length. Axillary pelvic lobe well developed. Mouth inferior. Rostral cap covering most of upper lip; smooth edge. Upper lip fused with upper jaw; continuous with lower lip around corner of mouth; edge smooth; small papillae present at corner connection with lower lip. Lower jaw straight; cornified at edge. Lateral and anterior portions of lower lip free, forming a distinct fleshy pad; posterior portion thinner and connected to upper lip; anterior edge with small papillae. Maxillary barbels present, shorter than eye diameter. Dorsal-fin rays iii,8, posteriormost split to base; anal-fin rays iii,5, posteriormost split to base; pelvic-fin rays i,8; pectoral-fin rays i,14–16, mode 15; principal caudal-fin rays 10+9, branched caudal-fin rays 9+8. Body entirely scaled, scales large. Lateral-line scales and pored scales on caudal fin 31–32 + 2–3, mode 32 + 2; predorsal scales 10–11, mode 11; scale rows above lateral line 5½; scale rows below lateral line 4½; scale rows between pelvic-fin origin and lateral line 3½ (rarely 3); circumpeduncular scales 16. Color in Preservative. See Figure 1. Dorsum of head and body brown, dark brown blotch posterior to eyes on head, black midline from posterior of head to caudal peduncle, approximately ¼ scale height in thickness, scales with fine black spots around posterior edges. Dorsal half of side of head light to dark brown, ventral half cream to yellow; silver on cheek and ventral half of operculum. Broad, black midlateral stripe extending from operculum to insertion of caudal fin, not extending onto middle caudal-fin rays. Thin cream to yellow stripe above anterior ¾ of midlateral stripe posterior to operculum, separating black midlateral stripe from brown dorso-lateral scales. Dorsolateral scales brown centrally with yellowish margin, overlain with scattered dark brown flecks on posterior edges; scales below midlateral stripe cream to yellow. Venter cream to yellow with silver patch on breast and isthmus. Dorsal fin with scattered black speckling, more concentrated on medial portions of interradial membranes. Caudal fin with scattered black speckling, concentrated on distal portions of upper and lower lobes and occasionally on middle rays. Pectoral, pelvic, and anal fins hyaline. Smaller specimens notably more silvery on head and body. Color in Life. See Figure 2. Dorsum of head and body yellowish-brown, golden-brown patch posterior to eyes on head. Black stripe from tip of snout to anterior edge of mid-eye, continuous after eye to operculum edge; black midline from posterior of head to caudal peduncle continuous to middle of caudal-fin margin. Gold stripe above black midline, ending at caudal-fin base. Posterior lower half of black midline slightly edged with gold. Lower half and ventrum of body cream. All fins hyaline, except dorsal-fin with mid-row of black pigments on interradial membrane and caudal fin with scattered black speckling. Remarks. The minimum polygon clusters formed by plotting the second and third sheared principal components of the morphometric data of L. aurolineatus, L. ixocheilos, and L. tenura are presented in Fig. 4. Size accounted for 98.4% of the observed variance. The second sheared principal component accounted for 4.0% of the observed variance. Mouth width (0.63) and body depth (-0.53) had the highest loadings on the sheared second principal component. The third sheared principal component accounted for 3.5% of the observed variance, and mouth width (0.61) and the length of the anal-fin base (-0.55) had the highest loadings. The minimum polygon of L. aurolineatus does not overlap with the polygons of L. ixocheilos and L. tenura, indicating the former is distinct in body shape from the latter two species. In the description of L. tenura, Kottelat & Tan (2008) tentatively noted that this species from the Kapuas basin in West Kalimantan, Indonesia was figured in Roberts (1989) as L. hispidus (Valenciennes, in Cuvier & Valenciennes). We examined two specimens listed by Roberts (1989) as L. hispidus (USNM 230178, 53.7–66.5 mm SL). Both of these specimens possess a slender caudal-peduncle depth (10.7–10.9% SL) within the range listed by Kottelat & Tan (2008) in diagnosing L. tenura. Specimens of L. ixocheilos examined here possess a deeper caudal peduncle (11.2–12.9% SL) as well, although this range is somewhat below the range of 12.3–13.7% SL listed by Kottelat & Tan (2008) in the description of that species. Despite some overlap in the minimum polygon clusters (Fig. 2), we tentatively identify these specimens as L. tenura based on differences in caudal-peduncle depth. Kottelat & Tan (2008) noted some variation in overall body depth among the types of L. tenura, with the holotype and one paratype (ZRC 51178) being more slender than the other type material. Here also the paratype is more slender than the other specimens examined (Fig. 2). Distribution. Lobocheilos aurolineatus occurs in the Mahakam River (up to Kampung Data Belang [00°13.968’N, 115°27.610’E]) and Lake Jempang, a seasonal floodplain of the river, in East Kalimantan, Indonesian Borneo (Fig. 5). Etymology. aurolineatus from the Latin aureus, gold, and lineatus, lined, in reference to the gold stripe along the flank in live specimens.Published as part of Ciccotto, Patrick J. & Tan, Heok Hui, 2018, A new species of Lobocheilos (Teleostei: Cyprinidae) from East Kalimantan, Indonesian Borneo, pp. 543-552 in Zootaxa 4399 (4) on pages 544-547, DOI: 10.11646/zootaxa.4399.4.4, http://zenodo.org/record/120686
Host-parasite interactions in tan spot [Pyrenophora tritici-repentis] of wheat
No full textTan spot of wheat, caused by the ascomycete Pyrenophora tritici-repentis, is an economically important disease in all the major wheat growing areas worldwide. Even though the pathogen was known to occur on grasses and episodically on wheat for more than eight decades, large-scale epidemics of tan spot were first recorded in the early 1970s. The increased incidence was associated with stubble retention, a practice implemented in the context of soil conservation. The present review highlights some of the recent developments that have occurred in studies of the wheat - P. tritici-repentis interaction and discusses the implications for our understanding of host-parasite relations in general. Races of P. tritici-repentis produce at least three host-specific toxins, effective on particular host lines or cultivars. Single dominant and independently inherited genes control host reaction to these toxins, with one gene for each toxin. Eight races of the pathogen have now been identified from collections made in several parts of the world, accounting for all virulence patterns expected from three toxins matching three "susceptibility" genes in the host. Genetic analyses of host and pathogen suggested that a one-to-one relationship existed in the wheat - P. tritici-repentis interaction. The model described for tan spot of wheat appears to be a mirror image of the classical gene-for-gene in that it is based on compatibility. Thus, it is proposed that the gene-for-gene model can be extended, as previously predicted by others, to pathosystems involving multiple host-specific toxins. The relationship between toxin production and the evolution of new races is also discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Otizm spektrum bozuklu u tan l çocukta motor becerilerinin geli iminin incelenmesi: Vaka çal mas
No full textAmaç: Otizm Spektrum Bozuklu u (OSB) tan s alm çocuklar n geli imsel sorunlar n
çözme temel amac ile bir vakan n öncelikli olarak motor geli im becerilerini
hedefleyen ve bununla birlikte di er geli im alanlar ndaki etkilerinin incelemesi
amaçlanm t r.
Gereç ve Yöntem: Ara t rmada karma ara t rma yöntemi ve aç mlay c s ral desen ile
çal lm t r. Kat l mc 5 ya nda OSB tan s alm bir erkek çocu udur. Veriler nicel
boyutta BüKBÖT ve Denver II testleri ile elde edilmi tir. Nitel boyutta gözlem, bireysel
görü me ve alan notlar ndan faydalan lm t r. Çocu un problemlerine özgü temelinde
motor becerileri kapsayan 6 ayl k bir program tasarlanm t r. Testler e itime
ba lamadan ve e itim bitiminde ilk ve son test eklinde tekrar edilmi tir.
Bulgular: Haz rlanan 6 ayl k motor geli im program ndan önce ve sonra yap lan testler
incelendi inde BüKBÖT alt boyutlar nesne kontrol ve lokomotor becerilerinde geli im
görülmü tür. Denver II testinin tüm alt boyutlar nda geli me görülmü tür. Nitel
yöntemler ile takibini yapt m z di er parametrelerde önemli geli meler sa lanm t r.
Sonuç: Sonuç olarak haz rlanan 6 ayl k motor geli im temelli program n n OSB tan l
çocu un geli im parametrelerinde ilerleme sa lad bulunmu tur. Çocuklar n geli im
sürecinde motor geli im parametrelerinin önemi bu çal mayla da desteklenmi tir
Iterative Soft Interference Cancellation Aided Minimum Bit Error Rate Uplink Receiver Beamforming
No full textIterative multiuser receivers constitute an effective solution for transmission over Multiple Access Interference (MAI) infested channels, when invoking a combined multiuser detector and channel decoder. Most reduced-complexity methods in this area use the Complex-valued Minimum Mean Squared Error (CMMSE) Multiuser Detector (MUD). Since the desired output of BPSK systems is real-valued, minimizing the Mean Square Error (MSE) between the beamformer’s desired output and the real part of the beamformer output has the potential of significantly improving the attainable Bit Error Rate (BER) performance. We refer to this MMSE design as the Real-valued MMSE (RMMSE) receiver. In this paper, we explore a new Soft-Input Soft-Output (SISO) interference cancellation multiuser detection algorithm based on the novel Minimum BER (MBER) criterion. We demonstrate that the MBER turbo receiver outperforms both the CMMSE and the RMMSE algorithms, particularly in so-called ‘overloaded’ beamforming systems, where the number of receiver antennas is lower than the number of users supported
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