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Microplastics (MPs) are increasingly being studied because they have become ubiquitous in aquatic and terrestrial environments. However, little is known about the negative effects of co-contamination by polypropylene microplastic (PP MPs) and heavy metal mixtures on terrestrial environment and biota. This study assessed the adverse effects of co-exposure to PP MPs and heavy metal mixture (Cu2+, Cr6+, and Zn2+) on soil quality and the earthworm Eisenia fetida. Soil samples were collected in the Dong Cao catchment, near Hanoi, Vietnam, and analyzed for changes in extracellular enzyme activity and carbon, nitrogen, and phosphorus availability in the soil. We determined the survival rate of earthworms Eisenia fetida that had ingested MPs and two doses of heavy metals (the environmental level — 1 × — and its double — 2 ×). Earthworm ingestion rates were not significantly impacted by the exposure conditions, but the mortality rate for the 2 × exposure conditions was 100%. Metal-associated PP MPs stimulated the activities of β-glucosidase, β-N-acetyl glucosaminidase, and phosphatase enzymes in soil. Principle component analysis showed that these enzymes were positively correlated with Cu2+ and Cr6+ concentrations, but negatively correlated with microbial activity. Zn2+ showed no correlation with soil extracellular enzyme activity or soil microbial activity. Our results showed that co-exposure of earthworms to MPs and heavy metals had no impact on soil nitrogen and phosphorus but caused a decrease in total soil carbon content, with a possible associated risk of increased CO2 emissions.

The latest data from the United States Renal Data Systems show over 134,000 individuals with end-stage kidney disease (ESKD) starting dialysis in the year 2019. ESKD patients on dialysis, the default treatment strategy, have high mortality and hospitalization, especially in the first year of dialysis. An alternative treatment strategy is (non-dialysis) conservative management (CM). The relative effectiveness of CM with respect to various patient outcomes, including survival, hospitalization, and health-related quality of life among others, especially in elderly ESKD or advanced chronic kidney disease patients with serious comorbidities, is an active area of research. A technical challenge inherent in comparing patient outcomes between CM and dialysis patient groups is that the start of follow-up time is “not defined” for patients on CM because they do not initiate dialysis. One solution is the use of putative dialysis initiation (PDI) time. In this work, we examine the validity of the use of PDI time to determine the start of follow-up for longitudinal retrospective and prospective cohort studies involving CM. We propose and assess the efficacy of estimating PDI time using linear mixed effects model of kidney function decline over time via simulation studies. We also illustrate how the estimated PDI time can be used to effectively estimate the survival distribution.

3. B. viridipallidum Vuong, Aver. & V.C.Nguyen sp. nov. (Fig. 2). Type:— VIETNAM. Kon Tum Province, Dak Ha District, Dak Psi Commune, Dak Trua Forest, epiphyte on tall trees, 16 February 2023, Truong Ba Vuong, BV 1688 (holotype VNM00043087!). Etymology: —the specific epithet refers to the pale greenish yellow lateral sepals, a character common with related species. Description:—Herb perennial, epiphytic. Pseudobulbs densely clustering, ovoid to broadly ovoid, sometime slightly compress, 7–16 mm long, 5–17 mm in diameter, 2-leaved. Leaves deciduous, plant leafless at anthesis. Inflorescence from base of pseudobulbs; peduncle greenish-yellow, 39 – 40 cm long, at base with 2 scarious, brownish overlapping tubular bracts, above with 2 similar bracts; rachis pendulous, 3.5 – 4 cm long, bearing 6 simultaneously opening flowers; floral bract triangular, brown 1.7–2 mm long, acute; pedicel and ovary 2.5–3 mm long, pedicel terete shorter than conoid ovary. Flowers odorless, lateral sepals pale greenish yellow; median sepal and petals pale reddish brown, lip white speckled with pink or pink purple, callus yellow, with many pink dots at apex dark purple. Median sepal ovate to broadly ovate, ca. 5.5 mm long, ca. 3 mm wide, acuminate to attenuate, adaxially in middle with 2 prominent keels, in apical half sparsely hairy with stiff hairs. Lateral sepals obliquely oblong lanceolate, ca. 4 cm long, ca. 0.3 cm wide, acute, twisted at base, lower margin free at base, connate to the tip, adaxial surface sparsely hairy with short stiff hairs. Petals obliquely triangular, glabrous, 4–4.5 mm long, 1–1.5 mm wide, margin fimbriate, acuminate to attenuate. Lip simple, oblong in outline, 3–3.2 mm long, 1–1.5 mm wide, movably adnate to column foot by small ligament, apex rounded; margins in basal half erect, finely papillose, apical half fimbriate along the margin; adaxial surface at base with 2 rounded longitudinal calli fused distally into a single prominent central longitudinal keel inflated at the lip apex turn into prominent half-ovoid callus; abaxial sparely pillose. Column ca. 1.5 mm long, at front with inconspicuous rounded wings; column foot 2–2.5 cm long, forward directed, straight; stelidia subulate, ca. 1 mm long, slightly curved; stigma half circular, concave, ca. 1 mm across; rostelum non protruding; anther cap helmet shaped, ca. 1 mm long, apex with a gibbose densely papillose inflation; pollinia 4, bright yellow, half ovoid, inner smaller than outer. Fruits not seen. Habitat and phenology: —Epiphyte on tall trees in evergreen broad-leaved forest. Flowering observed during February. Distribution: — VIETNAM (Kon Tum Province, Dak Ha District). Endemic. Proposed conservation status:—According to currently available data, the new species is very rare and found only from one location. More field studies are required for preparing its conservation assessment. In view of gaps in data and in accordance with IUCN criteria (IUCN, 2022), the species should be assessed as Data Deficient (DD). Notes:—The new species in its entire median sepal is similar B. kanburiense and B. khaoyaiense. It also similar with B. wallichii in two prominent calli placed on the lip base. The dorsal sepal and flower comparison is presented on Fig. 3. The morphological differences of the new species and morphologically similar species are presented in the table. Data of B. wallichii based on BV 1484 (VNM 00043086), BV 1483 (LE 01123508 & LE 01169312); data of B. kanburiense based on Seidenfaden (1970: 344); data of B. khaoyaiense based on Seidenfaden & Smitinand (1965: 795) and Seidenfaden (1970: 342).

4. B. refractum (Zollinger 1847: 456) Reichenbach (1861: 259), Seidenfaden (1970: 347), Averyanov (1994: 284), Seidenfaden (1992: 263). (Fig. 4). ≡ Cirrhopetalum refractum Zollinger 1847: 456. Type:— INDONESIA. Java, Zollinger, 2261 (G00165064 photo!). ≡ Phyllorkis refracta (Zollinger 1847: 456) Kuntze (1891: 677). ≡ Tripudianthes refracta (Zollinger 1847: 456) Szlachetko & Kras (2007: 96). Habitat and phenology: —Epiphyte on tall trees in primary evergreen broad-leaved forests. Flowering observed in December–February. Distribution: — Vietnam (Lam Dong, Gia Lai, Dak Nong, Binh Phuoc, Dien Bien provinces), Bhutan, India, Myanmar, Thailand, Java and Sumatra. Proposed conservation status:—According to currently available data, B. refractum seems quite common in Vietnam. Due to attractive nature of flowers, the species is widely collected for trade. Based on the national EOO 148,826.741 km 2 and AOO 28.000 km 2, and in accordance with IUCN criteria (IUCN, 2022), the species should be assessed in Vietnam as VU B2ab(v). The verifiable data for this species’ conservation status outside Vietnam is not available. Note:—Common in Vietnam, with relatively large flowers having a large dorsal sepal. The species is sometime misidentified as B. kanburiense; the main differences is indicated under the note for B. kanburiense. The drawing of Pham Hoang Ho (1992: 844) named as B. refractum possibly based on specimens of Tixier 15 (P 00348218) having a very small dorsal sepal typical for B. wallichii. Studied specimens: — VIETNAM, Lam Dong Province, Annam: piste de Fyan, 1957, Tixier, 15 (P 00348218 photo!). VIETNAM, Gia Lai Province, 1987, Averyanov, LX-VN 2143a/190a (photos LE 01057662!, LE 01087253!). VIETNAM, Binh Phuoc Province, 2005, Averyanov et al., HLF 4932a (photos LE 01087116!). VIETNAM, Lam Dong Province, 2011, NPT 006 (photos LE 0105766!, LE 01070245!). VIETNAM, Lam Dong Province, 2018, Truong Ba Vuong, Ngo Quang Dang, BV 1035 (VNM 00043084!). VIETNAM, Gia Lai Province, Truong Ba Vuong, BV 1083 (VNM 00043085!). VIETNAM, Dak Nong Province, 2019, Averyanov, Nguyen Van Canh, T. Maisak, AL 1183.4 (photos LE 01067185!). VIETNAM, Dak Lak, 2019, Truong Ba Vuong, BV 532 (VNM 00043069!). VIETNAM, Lam Dong Province, 2021, Truong Ba Vuong, Ngo Quang Dang, BV 1046 (photos LE 01089814!, VNM 00043072!). VIETNAM, Dien Bien Province, 2023, Nguyen Sinh Khang, AL 2191 (photos LE 01123884!). INDONESIA, Java, 1844, Zollinger, 2261 (isotype P 00347107 photo!)., Published as part of Nguyen, Van Canh, Averyanov, Leonid V., Maisak, Tatiana V., Nguyen, Thi Lien Thuong, Nguyen, Van Khuong, Pham, Thi Thanh Dat, Nguyen, Danh Duc, Dang, Van Son, Aromyen, Warapong & Truong, Ba Vuong, 2023, The review of Bulbophyllum section Tripudianthes (Orchidaceae) in the flora of Vietnam with the description of new species, B. viridipallidum, pp. 59-68 in Phytotaxa 598 (1) on pages 66-67, DOI: 10.11646/phytotaxa.598.1.4, http://zenodo.org/record/7958804, {"references":["Zollinger, H. (1847) Orchidaee. In: Observationes phytographicae, praecipue genera et species nova nonnulla respicientes. Flora oder Botanische Zeitung: welche Recensionen, Abhandlungen, Aufsatze, Neuigkeiten und Nachrichten, die Botanik betreffend, enthalt 30: 456.","Reichenbach, H. G. (1861) Orchides. In: Mueller, C. (ed.) Synopsis plantarum phanerogamicarum novarum omnium. Walpers Annales Botanices Systematicae 6: 167 - 933.","Seidenfaden, G. (1970) Contributions to the Orchid Flora of Thailand II. Botanisk Tidsskrift 65 (4): 313 - 370.","Averyanov, L. V. (1994) Identification guide to Vietnamese orchids. World & family. Saint-Petersburg. 432 pp.","Seidenfaden, G. (1992) The Orchid of Indochina. Opera Botanica 114: 1 - 502.","Kuntze, O. (1891) Cirrhopetalum refracta. Revisio generum plantarum: vascularium omnium atque cellularium multarum secundum leges nomenclaturae internationales cum enumeratione plantarum exoticarum in itinere mundi collectarum. Vol. 2. Leipzig. 1011 pp. https: // doi. org / 10.5962 / bhl. title. 124064","Szlachetko, D. L. & Kras, M. (2007) Contribution a la revision generique de Bulbophyllinae (Epidendroideae) 5 - Tripudianthes (Seidenfaden). Richardiana 7: 94 - 96.","IUCN Standards and Petitions Committee (2022) Guidelines for Using the IUCN Red List Categories and Criteria. Version 15.1. Prepared by the Standards and Petitions Committee. Available from: https: // nc. iucnredlist. org / redlist / content / attachment _ files / RedListGuidelines. pdf (accessed 2 April 2023)"]}

2. B. wallichii Reichenbach (1861: 259). (Fig. 1). Type:— NEPAL. 1832, Wall. Cat. n. 1980 (K000894326 photo!). ≡ Cirrhopetalum wallichii Lindley (1839: 72), non Wallich (1830: 51). ≡ Tripudianthes wallichii (Reichenbach) Szlachetko & Kras (2007: 96). ≡ Bulbophyllum refractoides Seidenfaden (1970: 342), nom. superfluum. Habitat and phenology: —Epiphyte on tall trees in evergreen broad-leaved forest. Distribution: — Vietnam (Lam Dong Province), Nepal, NE India, Myanmar, China, Thailand, Laos. Proposed conservation status:—According to currently available data, B. wallichii is found only in one location as a clustering epiphyte on tall tree in primary broad-leaved forest in Lam Dong Province. There is no direct threat to this habitat. Hence the species can be assessed in Vietnam as Vulnerable based on small AOO, VU D2. Meanwhile, there is insufficient data for global distribution area of this specie where its conservation status should be identified as Data Deficient (DD). Note:— Seidenfaden (1970: 342) considered the collection, Tixier 15 (P00348218) as Bulbophyllum refractoides, which is currently accepted as a synonym of B. wallichii. However, the line drawing of Tixier on the herbarium sheet clearly shows the dorsal sepal with stiff hairs on inner surface and on the margin (not fimbriate as in B. wallichii). We suspect the identification of this specimen may be incorrect. Meanwhile, additional specimens of the true B. wallichii were recently collected in Vietnam, in Lam Dong Province. These collections are presently confirmed by the voucher specimens (BV 1483, 1484) stored at LE (LE01169312! & LE01169312!) and VNM (VNM00043086!) Herbaria. At the same time, the specimen from NE India collected by Hooker and Thomson (P00362039) seem different from the type in a longer dorsal sepal with acuminate (not caudate) apex, and may represent separate variety or even species; which require detailed study. Studied specimens: — VIETNAM, Lam Dong Province, 14 December 2021, Truong Ba Vuong & Nguyen Phi Tam, BV 1483 (photos LE01123508!, LE01169312), BV 1484 (VNM00043086!). INDIA, Sikkim, Donné par M. M. J-D. Hooker et Thomson 1859 s.n. (P00362039 photo!). INDIA, Sikkim Himalaya, December 1892, Pantling 24 (P00362038 photo!)., Published as part of Nguyen, Van Canh, Averyanov, Leonid V., Maisak, Tatiana V., Nguyen, Thi Lien Thuong, Nguyen, Van Khuong, Pham, Thi Thanh Dat, Nguyen, Danh Duc, Dang, Van Son, Aromyen, Warapong & Truong, Ba Vuong, 2023, The review of Bulbophyllum section Tripudianthes (Orchidaceae) in the flora of Vietnam with the description of new species, B. viridipallidum, pp. 59-68 in Phytotaxa 598 (1) on page 61, DOI: 10.11646/phytotaxa.598.1.4, http://zenodo.org/record/7958804, {"references":["Reichenbach, H. G. (1861) Orchides. In: Mueller, C. (ed.) Synopsis plantarum phanerogamicarum novarum omnium. Walpers Annales Botanices Systematicae 6: 167 - 933.","Lindley, J. (1839) Cirrhopetalum in Miscellaneous Notices. Edwards's botanical register 25: 72.","Wallich, N. (1830) Cirrhopetalum wallichii. In: Plantae Asiaticae rariores, or, Descriptions and figures of a select number of unpublished East Indian plants. London, Treuttel and Wu ¨ rtz. pp. 53, Tab. 67. https: // doi. org / 10.5962 / bhl. title. 468","Szlachetko, D. L. & Kras, M. (2007) Contribution a la revision generique de Bulbophyllinae (Epidendroideae) 5 - Tripudianthes (Seidenfaden). Richardiana 7: 94 - 96.","Seidenfaden, G. (1970) Contributions to the Orchid Flora of Thailand II. Botanisk Tidsskrift 65 (4): 313 - 370."]}

1. B. tripudians Parish & Reichenbach (1875: 154), Seidenfaden (1970: 341, 1979: 189), Ormerod et al. (2021: 50). Type:— MYANMAR. Mon State: Mawlamyine District, Parish 308 (K 000829091 photo!). ≡ B. tripudianthe Shaw (2016: 124), nom. superfluum. ≡ Tripudianthes tripudians (Parish & Reichenbach 1875: 154) Szlachetko & Kras (2007: 96). Habitat and phenology: —Epiphyte on tall trees in broad-leaved evergreen forest. Flowering observed in February– March. Distribution: — Myanmar, Thailand, Laos, Vietnam (?). Proposed conservation status:—According to currently available data, B. tripudians is a very rare species recorded from a single collection made by Poilane in 1933. More field studies are necessary for the identification of its conservation status. In view of lack of current data and in accordance with IUCN criteria (IUCN, 2022), the species should be assessed as Data Deficient (DD). Note: —The occurrence of this species in Vietnam is based on a single collection by Poilane (P 00362016) made in Lam Dong Province, in Bao Loc District. However, specimens on the herbarium sheet (especially on the rightside) show a large dorsal sepal do not attenuate at apex that is typical for B. refractum, hence the identification on our opinion may be doubtful. Studied specimens: — VIETNAM, Lam Dong Province, “Annam: un peu au sud de la station agricole de Blao, prov. du Haut Donaï”, 1933, Poilane, 22157 (P 00362016 photo!)., Published as part of Nguyen, Van Canh, Averyanov, Leonid V., Maisak, Tatiana V., Nguyen, Thi Lien Thuong, Nguyen, Van Khuong, Pham, Thi Thanh Dat, Nguyen, Danh Duc, Dang, Van Son, Aromyen, Warapong & Truong, Ba Vuong, 2023, The review of Bulbophyllum section Tripudianthes (Orchidaceae) in the flora of Vietnam with the description of new species, B. viridipallidum, pp. 59-68 in Phytotaxa 598 (1) on pages 60-61, DOI: 10.11646/phytotaxa.598.1.4, http://zenodo.org/record/7958804, {"references":["Seidenfaden, G. (1970) Contributions to the Orchid Flora of Thailand II. Botanisk Tidsskrift 65 (4): 313 - 370.","Seidenfaden, G. (1979) Orchid genera in Thailand 8: Bulbophyllum. Dansk Botanisk Arkiv 33 (3): 1 - 228.","Ormerod, P, Kurzweil, H. & Watthana, S. (2021) Annotated List of Orchidaceae for Myanmar. Phytotaxa 481 (1): 1 - 262. https: // doi. org / 10.11646 / phytotaxa. 481.1.1","Shaw, J. M. H. (2016) Bulbophyllum tripudianthe in Orchid Review 124 (1314): 35.","Szlachetko, D. L. & Kras, M. (2007) Contribution a la revision generique de Bulbophyllinae (Epidendroideae) 5 - Tripudianthes (Seidenfaden). Richardiana 7: 94 - 96.","IUCN Standards and Petitions Committee (2022) Guidelines for Using the IUCN Red List Categories and Criteria. Version 15.1. Prepared by the Standards and Petitions Committee. Available from: https: // nc. iucnredlist. org / redlist / content / attachment _ files / RedListGuidelines. pdf (accessed 2 April 2023)"]}

5. B. kanburiense Seidenfaden (1970: 344), Seidenfaden (1979: 190), Ormerod et al. (2021: 36). Type: — THAILAND, Thawng Phaphum, Kanburi, Seidenfaden & Smitinand, GT 4259 (C). ≡ Tripudianthes kanburiensis (Seidenfaden) Szlachetko & Kras (2007: 95). Habitat and phenology: —Epiphyte on tall trees in primary evergreen broad-leaved forests. Distribution: — Myanmar, Thailand, Vietnam (?) Proposed conservation status:—According to currently available data, the occurrence of B. kanburiense in Vietnam is unclear. More field studies are required to confirm the distribution of this species in Vietnam. In view of lack of current data and in accordance with IUCN criteria (IUCN, 2022), the species is assessed nationally as Data Deficient (DD). The conservation status of this species outside Vietnam has not been evaluated yet. Studied specimens:— MYANMAR, 1932, Dickason 5770, (A02386360 photo!,AMES45519photo!). VIETNAM, Lam Dong, 1982, Averyanov, LX-VN 973 (photos LE01055686!, LE01055687!). Note:—This species is similar to B. refractum, from which it differs by having a smaller median sepal, less than 5.5 mm long (vs. median sepal longer than 8 mm), shorter lateral sepals 2.5 cm (vs. longer than 3 cm), and acuminate petals (vs. petals acute). Two collections housed in LE Herbarium: LE01055686 and LE01055687 identified as B. kanburiense show entire dorsal sepal and subulate petals typical for B. refractum according to Seidenfaden (1992: 261). However, these specimens have lateral sepals 3.5–4 cm long (vs. median sepal of B. kanburiense according to protologue is about 2.5 cm long), hence the identification of mentioned collection remains somewhat doubtful. We have not seen any more collections from Vietnam, which can confirm the occurrence of B. refractum in Vietnam., Published as part of Nguyen, Van Canh, Averyanov, Leonid V., Maisak, Tatiana V., Nguyen, Thi Lien Thuong, Nguyen, Van Khuong, Pham, Thi Thanh Dat, Nguyen, Danh Duc, Dang, Van Son, Aromyen, Warapong & Truong, Ba Vuong, 2023, The review of Bulbophyllum section Tripudianthes (Orchidaceae) in the flora of Vietnam with the description of new species, B. viridipallidum, pp. 59-68 in Phytotaxa 598 (1) on page 67, DOI: 10.11646/phytotaxa.598.1.4, http://zenodo.org/record/7958804, {"references":["Seidenfaden, G. (1970) Contributions to the Orchid Flora of Thailand II. Botanisk Tidsskrift 65 (4): 313 - 370.","Seidenfaden, G. (1979) Orchid genera in Thailand 8: Bulbophyllum. Dansk Botanisk Arkiv 33 (3): 1 - 228.","Ormerod, P, Kurzweil, H. & Watthana, S. (2021) Annotated List of Orchidaceae for Myanmar. Phytotaxa 481 (1): 1 - 262. https: // doi. org / 10.11646 / phytotaxa. 481.1.1","Szlachetko, D. L. & Kras, M. (2007) Contribution a la revision generique de Bulbophyllinae (Epidendroideae) 5 - Tripudianthes (Seidenfaden). Richardiana 7: 94 - 96.","IUCN Standards and Petitions Committee (2022) Guidelines for Using the IUCN Red List Categories and Criteria. Version 15.1. Prepared by the Standards and Petitions Committee. Available from: https: // nc. iucnredlist. org / redlist / content / attachment _ files / RedListGuidelines. pdf (accessed 2 April 2023)","Seidenfaden, G. (1992) The Orchid of Indochina. Opera Botanica 114: 1 - 502."]}

3. B. viridipallidum Vuong, Aver. & V.C.Nguyen sp. nov. (Fig. 2). Type:— VIETNAM. Kon Tum Province, Dak Ha District, Dak Psi Commune, Dak Trua Forest, epiphyte on tall trees, 16 February 2023, Truong Ba Vuong, BV 1688 (holotype VNM00043087!). Etymology: —the specific epithet refers to the pale greenish yellow lateral sepals, a character common with related species. Description:—Herb perennial, epiphytic. Pseudobulbs densely clustering, ovoid to broadly ovoid, sometime slightly compress, 7–16 mm long, 5–17 mm in diameter, 2-leaved. Leaves deciduous, plant leafless at anthesis. Inflorescence from base of pseudobulbs; peduncle greenish-yellow, 39 – 40 cm long, at base with 2 scarious, brownish overlapping tubular bracts, above with 2 similar bracts; rachis pendulous, 3.5 – 4 cm long, bearing 6 simultaneously opening flowers; floral bract triangular, brown 1.7–2 mm long, acute; pedicel and ovary 2.5–3 mm long, pedicel terete shorter than conoid ovary. Flowers odorless, lateral sepals pale greenish yellow; median sepal and petals pale reddish brown, lip white speckled with pink or pink purple, callus yellow, with many pink dots at apex dark purple. Median sepal ovate to broadly ovate, ca. 5.5 mm long, ca. 3 mm wide, acuminate to attenuate, adaxially in middle with 2 prominent keels, in apical half sparsely hairy with stiff hairs. Lateral sepals obliquely oblong lanceolate, ca. 4 cm long, ca. 0.3 cm wide, acute, twisted at base, lower margin free at base, connate to the tip, adaxial surface sparsely hairy with short stiff hairs. Petals obliquely triangular, glabrous, 4–4.5 mm long, 1–1.5 mm wide, margin fimbriate, acuminate to attenuate. Lip simple, oblong in outline, 3–3.2 mm long, 1–1.5 mm wide, movably adnate to column foot by small ligament, apex rounded; margins in basal half erect, finely papillose, apical half fimbriate along the margin; adaxial surface at base with 2 rounded longitudinal calli fused distally into a single prominent central longitudinal keel inflated at the lip apex turn into prominent half-ovoid callus; abaxial sparely pillose. Column ca. 1.5 mm long, at front with inconspicuous rounded wings; column foot 2–2.5 cm long, forward directed, straight; stelidia subulate, ca. 1 mm long, slightly curved; stigma half circular, concave, ca. 1 mm across; rostelum non protruding; anther cap helmet shaped, ca. 1 mm long, apex with a gibbose densely papillose inflation; pollinia 4, bright yellow, half ovoid, inner smaller than outer. Fruits not seen. Habitat and phenology: —Epiphyte on tall trees in evergreen broad-leaved forest. Flowering observed during February. Distribution: — VIETNAM (Kon Tum Province, Dak Ha District). Endemic. Proposed conservation status:—According to currently available data, the new species is very rare and found only from one location. More field studies are required for preparing its conservation assessment. In view of gaps in data and in accordance with IUCN criteria (IUCN, 2022), the species should be assessed as Data Deficient (DD). Notes:—The new species in its entire median sepal is similar B. kanburiense and B. khaoyaiense. It also similar with B. wallichii in two prominent calli placed on the lip base. The dorsal sepal and flower comparison is presented on Fig. 3. The morphological differences of the new species and morphologically similar species are presented in the table. Data of B. wallichii based on BV 1484 (VNM 00043086), BV 1483 (LE 01123508 & LE 01169312); data of B. kanburiense based on Seidenfaden (1970: 344); data of B. khaoyaiense based on Seidenfaden & Smitinand (1965: 795) and Seidenfaden (1970: 342)., Published as part of Nguyen, Van Canh, Averyanov, Leonid V., Maisak, Tatiana V., Nguyen, Thi Lien Thuong, Nguyen, Van Khuong, Pham, Thi Thanh Dat, Nguyen, Danh Duc, Dang, Van Son, Aromyen, Warapong & Truong, Ba Vuong, 2023, The review of Bulbophyllum section Tripudianthes (Orchidaceae) in the flora of Vietnam with the description of new species, B. viridipallidum, pp. 59-68 in Phytotaxa 598 (1) on pages 61-66, DOI: 10.11646/phytotaxa.598.1.4, http://zenodo.org/record/7958804, {"references":["IUCN Standards and Petitions Committee (2022) Guidelines for Using the IUCN Red List Categories and Criteria. Version 15.1. Prepared by the Standards and Petitions Committee. Available from: https: // nc. iucnredlist. org / redlist / content / attachment _ files / RedListGuidelines. pdf (accessed 2 April 2023)","Seidenfaden, G. (1970) Contributions to the Orchid Flora of Thailand II. Botanisk Tidsskrift 65 (4): 313 - 370.","Seidenfaden, G. & Smitinand, T. (1965) The orchids of Thailand (Preliminary list). Siam Society. 870 pp."]}

Bulbophyllum sect. Tripudianthes Seidenfaden (1979: 188). Type:— B. tripudians Parish & Reichenbach (1875: 154). = Tripudianthes Szlachetko & Kras (2007: 94). 10–11 species in Nepal, Bhutan, NE India, Myanmar, S China, Thailand, Laos, Vietnam, Java, and Sumatra. In Vietnam 3–5 species, 1 endemic. Identification key to species of Bulbophyllum section Tripudianthes reported in the flora of Vietnam Species, the occurrence of which needs confirmation are designated by asterisk (*) 1. Median sepal with entire margin........................................................................................................................................................2 –. Median sepal with ciliate or fimbriate margin....................................................................................................................................4 2. Median sepal attenuate, with filiform appendage at apex................................................................................................. B. wallichii –. Median sepal acuminate, rarely with short seta at apex.....................................................................................................................3 3. Median sepal ovate, acuminate; lateral sepals 3–5.5 cm long; petals acuminate.......................................................... B. tripudians * –. Median sepal narrowly ovate, acute; lateral sepals ca. 2.5 cm long; petals aristate.................................................. B. kanburiense * 4. Median sepals ovate, attenuate................................................................................................................................. B. viridipallidum –. Median sepal elliptic, obtuse to acute............................................................................................................................... B. refractum, Published as part of Nguyen, Van Canh, Averyanov, Leonid V., Maisak, Tatiana V., Nguyen, Thi Lien Thuong, Nguyen, Van Khuong, Pham, Thi Thanh Dat, Nguyen, Danh Duc, Dang, Van Son, Aromyen, Warapong & Truong, Ba Vuong, 2023, The review of Bulbophyllum section Tripudianthes (Orchidaceae) in the flora of Vietnam with the description of new species, B. viridipallidum, pp. 59-68 in Phytotaxa 598 (1) on page 60, DOI: 10.11646/phytotaxa.598.1.4, http://zenodo.org/record/7958804, {"references":["Seidenfaden, G. (1979) Orchid genera in Thailand 8: Bulbophyllum. Dansk Botanisk Arkiv 33 (3): 1 - 228.","Szlachetko, D. L. & Kras, M. (2007) Contribution a la revision generique de Bulbophyllinae (Epidendroideae) 5 - Tripudianthes (Seidenfaden). Richardiana 7: 94 - 96."]}

This study investigates the influence of personality traits on positivity at work and officer performance at the district-level administrative agency in Hanoi. Based on the information obtained from 420 officers, the structural equation model was adopted to assess the impact of the Big Five model of personality on positivity at work and job performance. The results showed a positive relationship between personality traits, positivity at work, and job performance. At the same time, positivity at work positively impacts officers’ job performance. These findings suggest recommendations for district-level administrative agencies to enhance positivity at work and improve officers’ performance. This paper provides empirical evidence of the role of the Big Five model of personality. In addition, this study can serve as a reference for further research on organizational behavior in both public and private organizations.

Placed in cavity resonators with three-dimensionally confined electromagnetic wave, the interaction between quasiparticles in solids can be induced by exchanging virtual cavity photons, which can have a non-local characteristic. Here we investigate the possibility of utilizing this nonlocality to realize the remote control of the topological transition in mesoscopic moir\'{e} superlattices at full filling (one electron/hole per supercell) embedded in a split-ring terahertz electromagnetic resonator. We show that gate tuning one moir\'{e} superlattice can remotely drive a topological band inversion in another moir\'{e} superlattice not in contact but embedded in the same cavity. Our study of remote on/off switching of a topological transition provides a novel paradigm for the control of material properties via cavity vacuum fields.

We explore theoretically how the topological properties of 2D materials can be manipulated by cavity quantum electromagnetic fields for both resonant and off-resonant electron-photon coupling, with a focus on van der Waals moir\'e superlattices. We investigate an electron-photon topological Chern number for the cavity-dressed energy minibands that is well defined for any degree of hybridization of the electron and photon states. While an off-resonant cavity mode can renormalize electronic topological phases that exist without cavity coupling, we show that when the cavity mode is resonant to electronic miniband transitions, new and higher electron-photon Chern numbers can emerge., Comment: 4 pages with 5 figures, plus bibliography and Supplementary Material

The study is done to analyse the serious relationship between psychological capital, organisational commitment, and job satisfaction in the fisheries sector, a case study of Fisheries Sub-Department of Thai Binh Province. The empirical data collects through 237 questionnaires surveyed by civil servants working at the Fisheries Sub-Department of Thai Binh Province. The study applies exploratory factor analysis, confirmatory factor analysis, structural equation modeling to evaluate the relationship between psychological capital, organisational commitment, and job satisfaction of civil servants. The analysis results show a direct impact of psychological capital on organisational commitment, and psychological capital has an indirect effect on job satisfaction. The results also show a correlation between organisational commitment and job satisfaction. The study suggested significant policy implications for the Fisheries Sub-Department of Thai Binh Province to increase organisational commitment and job satisfaction.

Conamomum vietnamense, a new species of Zingiberaceae family, has been discovered and described from Tay Nguyen (Central Highlands, Vietnam) in 2022. The present study described the preparation of essential oil from leaves and rhizomes of the plant by hydrodistillation process. Then, the chemical composition of these essential oils was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS), which indicated that limonene (18.74 and 26.20%) and eucalyptol (40.47 and 49.49%) were the main components, respectively. The essential oils also showed moderate antimicrobial activities against Gram-positive bacterial strains (Enterococcus faecalis ATCC 299212, Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579), Gram-negative bacterial strains (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Salmonella enterica ATCC 13076), and a pathogenic yeast (Candida albicans ATCC 10231) in the MIC range of 32–256 μg/mL, which was comparable to those of positive controls, streptomycin and cycloheximide. For the first time, the chemical composition and antimicrobial activity of the essential oil of C. vietnamense were studied.

Supplemental material, sj-docx-1-npx-10.1177_1934578X231167229 for Phytochemical Analysis of the Essential Oils From the Rhizomes of Three Vietnamese Curcuma Species and Their Antimicrobial Activity by Hieu Tran-Trung, Xuan Duc Dau, Thi Chung Nguyen, Hien Nguyen-Thi-Thu, Hieu Nguyen-Ngoc, Thi Giang An Nguyen, Van Trung Hoang, Dang-Khoa Nguyen, Danh Duc Nguyen, Chen Tran Van and Le Duc Giang in Natural Product Communications

Supplemental material, sj-docx-1-npx-10.1177_1934578X231167229 for Phytochemical Analysis of the Essential Oils From the Rhizomes of Three Vietnamese Curcuma Species and Their Antimicrobial Activity by Hieu Tran-Trung, Xuan Duc Dau, Thi Chung Nguyen, Hien Nguyen-Thi-Thu, Hieu Nguyen-Ngoc, Thi Giang An Nguyen, Van Trung Hoang, Dang-Khoa Nguyen, Danh Duc Nguyen, Chen Tran Van and Le Duc Giang in Natural Product Communications

Placed in cavity resonators with three-dimensionally confined electromagnetic wave, the interaction between quasiparticles in solids can be induced by exchanging virtual cavity photons, which can have a non-local characteristic. Here we investigate the possibility of utilizing this nonlocality to realize the remote control of the topological transition in mesoscopic moiré superlattices at full filling (one electron/hole per supercell) embedded in a split-ring terahertz electromagnetic resonator. We show that gate tuning one moiré superlattice can remotely drive a topological band inversion in another moiré superlattice not in contact but embedded in the same cavity. Our study of remote on/off switching of a topological transition provides a novel paradigm for the control of material properties via cavity vacuum fields.

We explore theoretically how the topological properties of 2D materials can be manipulated by cavity quantum electromagnetic fields for both resonant and off-resonant electron-photon coupling, with a focus on van der Waals moiré superlattices. We investigate an electron-photon topological Chern number for the cavity-dressed energy minibands that is well defined for any degree of hybridization of the electron and photon states. While an off-resonant cavity mode can renormalize electronic topological phases that exist without cavity coupling, we show that when the cavity mode is resonant to electronic miniband transitions, new and higher electron-photon Chern numbers can emerge., 4 pages with 5 figures, plus bibliography and Supplementary Material

A long-term field study on corrosion of STK400 steel was established at Phu My port. The large steel pile, which was equivalent to real structures, was placed in all environmental zones to evaluate the overall corrosive effects of the brackish water. After 5 years, the corrosion rate over the entire length of the steel pile was measured and the rust at the boundary altitude between the zones was characterized. The corrosion rate profile shows the polarization of the entire pile length into two large anodic areas at the highest water level and submerged zones, where had high corrosion rate and pitting corrosion form. X-ray diffraction and metallographic of rust layers showed that Fe3O4 phase increased with water depth, allowing to strong diffusion of Fe2+ ion from steel substrate into the environment. The change in organism populations along water altitude in the tidal and submerged zones made the rust layers more complicated. Such distribution of polarized electrodes and composition of rust were due to the renewal of the corrosive agent by tidal cycles and organism population in water. As a result, the steel substrate in the tidal and mud zones was protected as cathodic areas.

The purpose of the study is to examine the relationship of workplace turnover of officers with organizational commitment and job satisfaction at the Hanoi City Public Administration Centre. The structural equation model (SEM) was used to analyze the data provided by 246 officers working at the Hanoi City Public Administration Centre in order to assess the influence of organizational commitment and job satisfaction on workplace turnover. The results show a favorable correlation between organizational commitment and work satisfaction. In addition, job satisfaction and organizational commitment are negatively correlated with the workplace turnover of officers. The result of the study suggested several important implications for the Hanoi City Public Administration Centre on how to increase organisational commitment, job satisfaction in order to reduce workplace turnover of officers.

Microplastics (MPs) are increasingly being studied because they have become ubiquitous in aquatic and terrestrial environments. For example, little is known about the negative effects of co-contamination by polypropylene microplastic (PP MPs) and heavy metal mixtures on terrestrial environment and biota. This study assesses the adverse effects of co-exposure to PP MPs and heavy metal mixture (Cu2+, Cr6+ and Zn2+) on soil quality and the earthworm Eisenia foetida. Soil samples were collected in the Dong Cao catchment, near Hanoi, Vietnam, and analyzed for changes in extracellular enzyme activity and carbon, nitrogen and phosphorus availability in the soil. We determined the survival rate of earthworms Eisenia foetida that had ingested MPs and two doses of heavy metals (the environmental level – 1X – and its double – 2X). Earthworm ingestion rates were not significantly impacted by the exposure conditions but the mortality rate for the 2X exposure conditions was 100%. Metals-associated PP MPs stimulated the activities of β-glucosidase, β-N-acetyl glucosaminidase and phosphatase enzymes in soil. Principle component analysis showed that these enzymes were positively correlated with Cu2+ and Cr6+ concentrations, but negatively correlated with microbial activity. Zn2+ showed no correlation with soil extracellular enzyme activity or soil microbial activity. Our results showed that co-exposure of earthworms to MPs and heavy metals had no impact on soil nitrogen and phosphorus but caused a decrease in total soil carbon content, with a possible associated risk of increased CO2 emissions.

Sea level rise and land subsidence — induced flooding are projected to have severe impacts on highly populated Asian deltaic cities. These cities are already suffering from frequent floods, though few comparative analyses have been conducted on the similarities and differences of their adaptation approaches. Thus, this study aims to investigate the current adaptation pathways of Asian deltaic cities to flooding induced by slow onset events such as urbanization-induced land subsidence and sea level rise, by looking at Tokyo, Jakarta, Manila, and Ho Chi Minh City as case studies. Evidence from them shows that an engineering approach towards flooding adaptation is shaping the future of Asian deltaic cities. However, emerging challenges question the sustainability of this approach. Recommendations on how to improve current adaptation pathways and direction for future research are also provided.

Tupistra thangii N. Tanaka & D.D.Nguyen, sp. nov. Differs from the most similar species T. clarkei mainly by its wider leaves, upright or ascending spike, smaller flowers, perianth dark purple on both sides, laterally strongly revolute perianth lobes, and stamens adnate to the subbasal portion of the lobes. Type:— VIETNAM. Lam Dong Province: Bao Lam District, Loc Bao Commune, around point 11°44’16.8”N 107°42’08.4”E; flat areas to steep slopes along river valley at elevation 800–900 m a.s.l.; very humid, primary to secondary broad-leaved forest mixed with bamboo; terrestrial herb with leaves to 1.5 m long in acidic soil rich in silicates, rarely on shady wet rocks, common locally; 18 December 2021, Nguyen Danh Duc & Nguyen Van Canh 2021493 (holotype VNMN). Description:— Plant terrestrial, herbaceous, rosulate, rhizomatous, glabrous, perennial. Rhizome ascending to erect, usually unbranched, terete, stout, dirty brown, 7–15 cm long, 2.5–3.5 cm in diameter, covered with brown, coriaceous, partially disintegrated remnants of cataphylls and leaf sheaths. Roots sparse, almost straight or curved downward from near base, cord-like, fleshy, 2–6 mm in diameter, covered throughout with light brown root hairs. Stem erect, 2–6 cm long, enclosed by distichous conduplicate leaf sheaths and cataphylls. Cataphylls straight, ensiform or narrowly triangular, conduplicate, light grassy green, turning white in proximal half with age, 10–20 cm long, (1.5)2.5–4(6)cm wide (at base when flattened), basal portion abruptly widened up to 6 cm wide, soon becoming dry, coriaceous and almost brown, withering earlier than foliage leaves. Leaves (4)6–10(12), erect, arcuate or distally pendulous, basally equitant, (0.8)0.9–1.6(1.8) m long; blade narrowly elliptic to oblanceolate, (40–)50–60(–70) cm long, (5)7–18(20) cm wide (at the widest portion), wavy, leathery, uniformly dark green, glossy, midvein prominent abaxially, gradually tapering to thick, rigid, canaliculate petiole-like base (10–)15–30(–40) cm long, apex acute to shortly acuminate. Peduncle arising from leaf axil in distal part of stem, erect, oblique or almost horizontal, straight or ascending, slightly thickened upward, obscurely angled longitudinally, naked, fleshy, rigid, erect and reddish green at early anthesis, becoming curved and white at late anthesis, elongating with age; 7–10 cm long at early anthesis, 10–15 cm at late anthesis, and 20–30 cm after anthesis (or in fruit), 6 mm in diameter. Inflorescence (excluding peduncle) a dense spike, many-flowered, upright or ascending, 10–15 cm long, 3–3.5 cm in diameter; rachis obscurely and irregularly multi-angled longitudinally, fleshy, pinkish, turning green at late anthesis, portions from which flowers arise slightly concave. Bracts borne directly on rachis, 2 per flower, scarious along margins; outer bract located 2–3 mm below flower base, cucullate, obscurely rectangular, rather fleshy, white or light green, 4–6 mm long and wide, truncate to acute at apex, after anthesis becoming dry, brown and coriaceous; inner bract (bracteole) located lateral to flower, ovate to rectangular, light greenish, 3–4 mm long, 2.5–3 mm wide, apically acuminate, antrorse. Flower buds obliquely spheroidal or oblate, external side of perianth lobes dull whitish green with purplish rims. Flowers sessile, actinomorphic (or slightly zygomorphic), 1.2–1.6 cm across; Perianth 6-parted, broadly campanulate, dull dark purple to reddish purple, fleshy, with 6 white longitudinal stripes which correspond to decurrent portions of staminal filaments; proximal tube cup-like, 2.5–3.5 mm high, 5–7 mm in diameter; distal lobes broadly ovate, laterally strongly revolute (hence lobes look narrowly triangular), 6–8 mm long, 5–7mm wide. Stamens 6, opposite to perianth lobes; filaments adnate to subbasal portion of perianth lobes, shortly subterete, fleshy, 0.3–0.5 mm long, 0.4–0.6 mm in diameter, white, portions adnate (decurrent) to the perianth tube white; anthers dorsifixed, elliptic or broadly ovate, concavo-convex, pale yellowish, introrse, 1.4–1.6 mm long, 1.2–1.4 mm wide; pollen yellow. Pistil 1, straight (horizontal) or slightly ascending, 11–13 mm long; ovary superior, shortly subterete or oblate, later becoming ovoid, 1.2–1.8 mm long, 2–2.5 mm wide, glossy, cream white, turning green at late anthesis; style cylindric, white to pale yellow, 9.5–11.2 mm long, (0.5)1.3–1.5(1.6) mm in diameter; stigma peltate with nearly flat top, 2- to 7-lobed, each lobe somewhat irregularly dentate-crenate, white to pale yellow, turning pale brown with age, frontal surface papillulate, 3–5 mm in diameter. Fruiting scape descending or curved downward, but distal part of infructescence ascending. Immature fruit globular, fleshy, dark green, ca. 3 cm in diameter, verruculose, normally 2-seeded; seeds ellipsoid or ovoid, ivory or off-white in color. Etymology: —The specific epithet honors Hoang Minh Thang who is a Vietnamese gardener and the first discoverer of this new species. Habitat and conservation status: — Tupistra thangii occurs on the floor of a primary to secondary evergreen broad-leaved forest mixed with bamboo at elevations 800– 900 m. Approximately 100 mature plants of this species were found in an area of 1 km 2 along a stream. They usually grew terrestrially on flat or steep locations, but sometimes also on shady wet rocks. The soil was rich in silicates and acidic. The habitat area as a whole, including its biotic and abiotic elements, appears not particularly endangered or damaged by human activities such as deforestation, but may be partially disturbed by grazing and/or trekkers’ camping. Since our data on the distribution and ecological aspects of this species are still very limited, we assign the species to the category “Data Deficient (DD)” in IUCN (2022). Distribution: ―Currently known only from the type locality in Lam Dong Province, southern Vietnam. Phenology: —Flowering in November–December. Fruiting: Only immature green fruit has been seen. Judging from the states of ripening fruit in May (Fig. 1J) and December (Fig. 1I), full ripening may require at least one year and a few months after fertilization (Tanaka 2010a). Taxonomic relationships:— Tupistra thangii is most similar to T. clarkei Hooker (1892: 325) from eastern Nepal and northeastern India (Tanaka 2010a), for it shares (broadly) campanulate flowers with ovate or broadly ovate, slightly recurved lobes, perianth tubes internally dark purple with six white longitudinal stripes, and peltate stigmas with a dentate-crenate margin. However, it differs from the latter mainly by its wider (up to 20 vs. 11 cm) leaves, upright or ascending (vs. descending) spike, smaller flowers (1.2–1.6 vs. 1.5–2.5 cm in diameter), perianth dark purple on both sides (vs. pale dull yellowish brown except internally dark purple perianth tube), laterally more strongly revolute perianth lobes, stamens adnate to the subbasal (vs. basal) portion of perianth lobes, and whitish (vs. purplish) stigma. The new species is also similar to T. natmataungensis Y.H. Tan & H.B. Ding in Ding et al. (2019: 137) described recently from western Myanmar in sharing campanulate flowers, internally white-striped, dark purple perianth tube, whitish peltate stigma, etc. It is, however, distinguished chiefly by its ascending or erect (vs. creeping) rhizome, wider (to 20 vs. to 3.8 cm) leaves, much longer (7–15 vs. 1–1.6 cm at anthesis) peduncle, much longer (10–15 vs. 5.1–6 cm), ascending (vs. nearly horizontal) spike, numerous (vs. 3), smaller (1.2–1.6 vs. ca. 2.7–3.2 cm in diameter), aerial (vs. epigenous) flowers, abaxially dark (reddish) purple (vs. pale yellow orange) perianth, laterally more strongly revolute perianth lobes, stamens arising from the subbasal (vs. basal) portion of perianth lobes, and 2- to 7-lobed (vs. 3-lobed) stigma. It is quite a unique trait that these three species possess an internally white-striped, dark purple perianth tube. Interestingly, this trait is also shared by other species having a pendulous spike such as T. fungilliformis F.T.Wang & S.Yun Liang in Wang & Tang (1978: 249) and T. tupistroides (Kunth 1850: 319) Dandy (1932: 329) (Tanaka 2010a). Since most other species of Tupistra (Tanaka 2010a) and all species of Rohdea (Tanaka 2010b) have an upright or ascending spike, the pendulous spike is deemed as an advanced or specialized state (i.e. apomorphy) originated from the upright or ascending spike (plesiomorphy). In this respect, T. thangii is viewed as retaining a more primitive state than T. natmataoungensis with an almost horizontal spike and T. clarkei and some other species (e.g. T. fungilliformis) with a pendulous spike. As these species are considered to be monophyletic, sharing a white-striped purple perianth as a synapomorphy, the ancestor of T. thangii is likely to have been deeply associated with the evolution of species with such non-ascending spikes. It is also of interest that T. thangii, T. clarkei and T. natmataoungensis are far apart in distribution in spite of their presumed phyletic proximity. This disjunctive distribution may not only reflect the past long-distance migration of this plant group, but also implies close historical connections between the floras of the Central Highlands of southern Vietnam, eastern Himalayan region and western Myanmar. The present discovery of Tupistra thangii in southern Vietnam has largely extended the known range of this genus in eastern Indochina (e.g. Averyanov & Tanaka 2012, Averyanov et al. 2015, Tanaka et al. 2018) southward. This suggests that new members of Tupistra may still be found by further floristic expeditions in regions between Lam Dong Province and the northern regions of Vietnam.

Tupistra thangii N. Tanaka & D.D.Nguyen, sp. nov. Differs from the most similar species T. clarkei mainly by its wider leaves, upright or ascending spike, smaller flowers, perianth dark purple on both sides, laterally strongly revolute perianth lobes, and stamens adnate to the subbasal portion of the lobes. Type:— VIETNAM. Lam Dong Province: Bao Lam District, Loc Bao Commune, around point 11°44’16.8”N 107°42’08.4”E; flat areas to steep slopes along river valley at elevation 800–900 m a.s.l.; very humid, primary to secondary broad-leaved forest mixed with bamboo; terrestrial herb with leaves to 1.5 m long in acidic soil rich in silicates, rarely on shady wet rocks, common locally; 18 December 2021, Nguyen Danh Duc & Nguyen Van Canh 2021493 (holotype VNMN). Description:— Plant terrestrial, herbaceous, rosulate, rhizomatous, glabrous, perennial. Rhizome ascending to erect, usually unbranched, terete, stout, dirty brown, 7–15 cm long, 2.5–3.5 cm in diameter, covered with brown, coriaceous, partially disintegrated remnants of cataphylls and leaf sheaths. Roots sparse, almost straight or curved downward from near base, cord-like, fleshy, 2–6 mm in diameter, covered throughout with light brown root hairs. Stem erect, 2–6 cm long, enclosed by distichous conduplicate leaf sheaths and cataphylls. Cataphylls straight, ensiform or narrowly triangular, conduplicate, light grassy green, turning white in proximal half with age, 10–20 cm long, (1.5)2.5–4(6)cm wide (at base when flattened), basal portion abruptly widened up to 6 cm wide, soon becoming dry, coriaceous and almost brown, withering earlier than foliage leaves. Leaves (4)6–10(12), erect, arcuate or distally pendulous, basally equitant, (0.8)0.9–1.6(1.8) m long; blade narrowly elliptic to oblanceolate, (40–)50–60(–70) cm long, (5)7–18(20) cm wide (at the widest portion), wavy, leathery, uniformly dark green, glossy, midvein prominent abaxially, gradually tapering to thick, rigid, canaliculate petiole-like base (10–)15–30(–40) cm long, apex acute to shortly acuminate. Peduncle arising from leaf axil in distal part of stem, erect, oblique or almost horizontal, straight or ascending, slightly thickened upward, obscurely angled longitudinally, naked, fleshy, rigid, erect and reddish green at early anthesis, becoming curved and white at late anthesis, elongating with age; 7–10 cm long at early anthesis, 10–15 cm at late anthesis, and 20–30 cm after anthesis (or in fruit), 6 mm in diameter. Inflorescence (excluding peduncle) a dense spike, many-flowered, upright or ascending, 10–15 cm long, 3–3.5 cm in diameter; rachis obscurely and irregularly multi-angled longitudinally, fleshy, pinkish, turning green at late anthesis, portions from which flowers arise slightly concave. Bracts borne directly on rachis, 2 per flower, scarious along margins; outer bract located 2–3 mm below flower base, cucullate, obscurely rectangular, rather fleshy, white or light green, 4–6 mm long and wide, truncate to acute at apex, after anthesis becoming dry, brown and coriaceous; inner bract (bracteole) located lateral to flower, ovate to rectangular, light greenish, 3–4 mm long, 2.5–3 mm wide, apically acuminate, antrorse. Flower buds obliquely spheroidal or oblate, external side of perianth lobes dull whitish green with purplish rims. Flowers sessile, actinomorphic (or slightly zygomorphic), 1.2–1.6 cm across; Perianth 6-parted, broadly campanulate, dull dark purple to reddish purple, fleshy, with 6 white longitudinal stripes which correspond to decurrent portions of staminal filaments; proximal tube cup-like, 2.5–3.5 mm high, 5–7 mm in diameter; distal lobes broadly ovate, laterally strongly revolute (hence lobes look narrowly triangular), 6–8 mm long, 5–7mm wide. Stamens 6, opposite to perianth lobes; filaments adnate to subbasal portion of perianth lobes, shortly subterete, fleshy, 0.3–0.5 mm long, 0.4–0.6 mm in diameter, white, portions adnate (decurrent) to the perianth tube white; anthers dorsifixed, elliptic or broadly ovate, concavo-convex, pale yellowish, introrse, 1.4–1.6 mm long, 1.2–1.4 mm wide; pollen yellow. Pistil 1, straight (horizontal) or slightly ascending, 11–13 mm long; ovary superior, shortly subterete or oblate, later becoming ovoid, 1.2–1.8 mm long, 2–2.5 mm wide, glossy, cream white, turning green at late anthesis; style cylindric, white to pale yellow, 9.5–11.2 mm long, (0.5)1.3–1.5(1.6) mm in diameter; stigma peltate with nearly flat top, 2- to 7-lobed, each lobe somewhat irregularly dentate-crenate, white to pale yellow, turning pale brown with age, frontal surface papillulate, 3–5 mm in diameter. Fruiting scape descending or curved downward, but distal part of infructescence ascending. Immature fruit globular, fleshy, dark green, ca. 3 cm in diameter, verruculose, normally 2-seeded; seeds ellipsoid or ovoid, ivory or off-white in color. Etymology: —The specific epithet honors Hoang Minh Thang who is a Vietnamese gardener and the first discoverer of this new species. Habitat and conservation status: — Tupistra thangii occurs on the floor of a primary to secondary evergreen broad-leaved forest mixed with bamboo at elevations 800– 900 m. Approximately 100 mature plants of this species were found in an area of 1 km 2 along a stream. They usually grew terrestrially on flat or steep locations, but sometimes also on shady wet rocks. The soil was rich in silicates and acidic. The habitat area as a whole, including its biotic and abiotic elements, appears not particularly endangered or damaged by human activities such as deforestation, but may be partially disturbed by grazing and/or trekkers’ camping. Since our data on the distribution and ecological aspects of this species are still very limited, we assign the species to the category “Data Deficient (DD)” in IUCN (2022). Distribution: ―Currently known only from the type locality in Lam Dong Province, southern Vietnam. Phenology: —Flowering in November–December. Fruiting: Only immature green fruit has been seen. Judging from the states of ripening fruit in May (Fig. 1J) and December (Fig. 1I), full ripening may require at least one year and a few months after fertilization (Tanaka 2010a). Taxonomic relationships:— Tupistra thangii is most similar to T. clarkei Hooker (1892: 325) from eastern Nepal and northeastern India (Tanaka 2010a), for it shares (broadly) campanulate flowers with ovate or broadly ovate, slightly recurved lobes, perianth tubes internally dark purple with six white longitudinal stripes, and peltate stigmas with a dentate-crenate margin. However, it differs from the latter mainly by its wider (up to 20 vs. 11 cm) leaves, upright or ascending (vs. descending) spike, smaller flowers (1.2–1.6 vs. 1.5–2.5 cm in diameter), perianth dark purple on both sides (vs. pale dull yellowish brown except internally dark purple perianth tube), laterally more strongly revolute perianth lobes, stamens adnate to the subbasal (vs. basal) portion of perianth lobes, and whitish (vs. purplish) stigma. The new species is also similar to T. natmataungensis Y.H. Tan & H.B. Ding in Ding et al. (2019: 137) described recently from western Myanmar in sharing campanulate flowers, internally white-striped, dark purple perianth tube, whitish peltate stigma, etc. It is, however, distinguished chiefly by its ascending or erect (vs. creeping) rhizome, wider (to 20 vs. to 3.8 cm) leaves, much longer (7–15 vs. 1–1.6 cm at anthesis) peduncle, much longer (10–15 vs. 5.1–6 cm), ascending (vs. nearly horizontal) spike, numerous (vs. 3), smaller (1.2–1.6 vs. ca. 2.7–3.2 cm in diameter), aerial (vs. epigenous) flowers, abaxially dark (reddish) purple (vs. pale yellow orange) perianth, laterally more strongly revolute perianth lobes, stamens arising from the subbasal (vs. basal) portion of perianth lobes, and 2- to 7-lobed (vs. 3-lobed) stigma. It is quite a unique trait that these three species possess an internally white-striped, dark purple perianth tube. Interestingly, this trait is also shared by other species having a pendulous spike such as T. fungilliformis F.T.Wang & S.Yun Liang in Wang & Tang (1978: 249) and T. tupistroides (Kunth 1850: 319) Dandy (1932: 329) (Tanaka 2010a). Since most other species of Tupistra (Tanaka 2010a) and all species of Rohdea (Tanaka 2010b) have an upright or ascending spike, the pendulous spike is deemed as an advanced or specialized state (i.e. apomorphy) originated from the upright or ascending spike (plesiomorphy). In this respect, T. thangii is viewed as retaining a more primitive state than T. natmataoungensis with an almost horizontal spike and T. clarkei and some other species (e.g. T. fungilliformis) with a pendulous spike. As these species are considered to be monophyletic, sharing a white-striped purple perianth as a synapomorphy, the ancestor of T. thangii is likely to have been deeply associated with the evolution of species with such non-ascending spikes. It is also of interest that T. thangii, T. clarkei and T. natmataoungensis are far apart in distribution in spite of their presumed phyletic proximity. This disjunctive distribution may not only reflect the past long-distance migration of this plant group, but also implies close historical connections between the floras of the Central Highlands of southern Vietnam, eastern Himalayan region and western Myanmar. The present discovery of Tupistra thangii in southern Vietnam has largely extended the known range of this genus in eastern Indochina (e.g. Averyanov & Tanaka 2012, Averyanov et al. 2015, Tanaka et al. 2018) southward. This suggests that new members of Tupistra may still be found by further floristic expeditions in regions between Lam Dong Province and the northern regions of Vietnam., Published as part of Nguyen, Danh Duc, Nguyen, Van Canh & Tanaka, Noriyuki, 2022, Tupistra thangii (Asparagaceae), a new species from southern Vietnam, pp. 267-273 in Phytotaxa 552 (4) on pages 268-271, DOI: 10.11646/phytotaxa.552.4.4, http://zenodo.org/record/6785883, {"references":["IUCN (2022) Guidelines for using the IUCN red list categories and criteria, version 15. Prepared by the Standards and Petitions Committee. Available from: https: // www. iucnredlist. org / documents / RedListGuidelines. pdf (accessed 15 March 2022)","Tanaka, N. (2010 a) A taxonomic revision of the genus Tupistra (Asparagaceae). Makinoa New Series 9: 55 - 93.","Hooker, J. D. (1892) Flora of British India 6 (part 18), L. Reeve & Co., London, pp. 225 - 448.","Ding, H. B., Yang, B., Zhou, S. S., Maw, M. B. & Maung, K. W. (2019) New contributions to the flora of Myanmar I. Plant Diversity 41 (3): 135 - 152. https: // doi. org / 10.1016 / j. pld. 2019.05.002","Wang, F. T. & Tang, T. (1978) Flora Reipublicae Popularis Sinicae 15. Science Press, Beijing, 280 pp.","Kunth, C. S. (1850) Enumeratio Plantarum 5. Sumtibus J. G. Cottae, Stutgardiae et Tubingae, 908 pp.","Dandy, J. E. (1932) Tupistra tupistroides (Kunth) Dandy. Journal of Botany, British and Foreign, London 70: 329.","Tanaka, N. (2010 b) A taxonomic revision of the genus Rohdea (Asparagaceae). Makinoa New Series 9: 1 - 54.","Averyanov, L. V. & Tanaka, N. (2012) New species of Peliosanthes and Tupistra (Aparagaceae) from eastern Indochina. Taiwania 57 (2): 153 - 167. [http: // tai 2. ntu. edu. tw / taiwania / pdf / tai. 2012.57.153. pdf]","Averyanov, L. V., Tanaka, N., Nguyen, K. S., Nguyen, H. T. & Konstantinov, E. L. (2015) New species of Ophiopogon Ker Gawl., Peliosanthes Andrews and Tupistra Ker Gawl. (Asparagaceae) in the flora of Laos and Vietnam. Adansonia, ser. 3, 37 (1): 25 - 45.","Tanaka, N., Hannon, D. P. & Vislobokov, N. A. (2018) Tupistra siphonantha (Asparagaceae), a new species from Lao P. D. R. with a simple pistil. Kew Bulletin 73: 32. http: // dx. doi. org / 10.1007 / S 12225 - 018 - 9754 - 5"]}

This paper “describes” the investigation of the stability of a single Degree of Freedom (DOF) flexible robotic arm by the diagrams shown below. The derived model is based on Euler- Lagrange approach. Exploration of a flexible robotic arm with using state-of-the-art controllers is essential for intelligent applications. These robot arms have joints that work independently of each other in order to create a smooth connection between joints. They still ensures the natural properties like a real human arm. The use of polarity assignment method “helps” the system to achieve desired output signals which has not been thoroughtly studied before for this system. The author can also compare the effectiveness of control methods for this system to find the most effective method for control strategies. In particular, ANN ( artificial neural network) is the most modern technique currently applied to this system to investigate the security and stability of the system through this program. This is new and it has never been used before for a system of this type. Neural networks strategy has been implemented in this paper as an application of artificial intelligence. It has successfully performed a mission in re-simulating functions of another control method: Polarity assignment method. Simulation results are done by Matlab.

Today, classical control methods are still widely used because of their excellent performance in a working enviroment with noise signals. Besides, they are suitble for functiions of the system : operations to control a machine are more flexible, easy to perform, less unwanted risks occur, the efficiency of controlling a system better. In the early years of the 21st century, traditional algorithms still promote their effects. Besides the traditional control methods, the author has applied more moderm and smarter algorithms such as adjusting Linear Quadratic Gaussian (LQG) to control a system on the ground or a system moving in the air. In the paper, LQG regulator is applied to a flight model to demonstrate its effectiveness in all cases. LQG regulator has not been applied before for this model. Results are as expected by the author for the working enviroment with noise signals affecting the system. Kalman filter used in this paper has shown its usefulness in the problem of dealing with unwanted signals. Simulation is done by Matlab.

The study aims to analyse the impact of personality traits on multidimensional organisational commitment of public servants working at the Administrative units and in Public non-business units of the Hanoi People’s Committee in Vietnam. From the data provided by 587 public servants at the Administrative units and Public non-business units, the structural equation model was applied to evaluate the impact of personality traits on three components of organisational commitment. The results showed a positive relationship between conscientiousness, extroversion, and agreeableness with multidimensional organisational commitment. Besides, openness to new experiences and neuroticism are negatively correlated with multidimensional organisational commitment. The result of the study suggests significant implications for Administrative units and Public non-business units of the Hanoi People’s Committee to increase organisational commitment of public servants in the future.

Improvement to the image of fractured granite basements is among the most sought-after goals for processing seismic data in Cuu Long basin, the most proliferous petroleum basin. Unlike a clear layering structure of the sediment, fuzzy images of the granite basement are often the source of confusion for interpreters to identify which structures are presented inside it. In such a low signal to noise ration (SNR) environment, extracting geological information such as fault systems and fracture becomes challenging. In this study, diffraction imaging is employed in an effort to identify and enhance the fault system inside the basement. The comparison of the study result with various standard post-stack attribute approaches shows the effectiveness of the diffraction imaging method.

The introduction, methods, results, and discussion (IMRaD structure) is a structure used by many journals and publishers in its publications since the early twentieth century. This research aims to survey and analyze some prestigious Open Access journals in the field of educational science in the world and in Vietnam on the use of IMRaD structure in presenting research results. We selected 05 open journals with the highest IF in the 2018 Scopus list and 05 prestigious journals in this field in Vietnam to conduct analysis of the articles in the latest 03 issues of these journals. The results of the survey of manuscript draft requirements and the frequency of articles written according to the IMRaD structure of the above journals show that: the IMRaD structure is commonly used in the articles in the field of Educational science in the world. However, in Vietnam, there is no journal that fully meets the contents compared to the basic IMRaD structure. The analysis of the content of articles published in journals in Vietnam shows that the weakest point of the researches is that the research methodology section is almost absent. Finally, we propose some solutions to improve scientific editing in Educational science journals in Vietnam to meet international publishing standards.

The sustainable livelihoods framework (SLF) is a comprehensive way to study agricultural issues. So far, to our best knowledge, no study has applied the SLF to examine the influence of land quality on land use intensively. The current research examines the effects of land quality on farmers’ decision-making on land use in Vietnam by modifying the sustainable livelihoods framework and using the fixed effects regression model. The method controlled the household and commune-level unobserved invariant characteristics and resulted in more robust estimates than pooled Ordinary Least Squares (OLS) estimation. The sample is a five-wave panel dataset of 2008-2016 with 1,534 farm households. The results reveal that land quality affects land-use choices through several aspects of land quality. More specifically, regarding topography, plot fertility level, plot locations, and soil and water conservation, results show that their effects reflect the cultivating practices for each land-use type in the sample. Findings also show that the irrigation system positively affects rice production in Vietnam. Policymakers should consider various aspects of land quality when designing policies and programs relating to land use, irrigation distribution, and especially the master plan for agricultural production and rural development. Flexible guidance for land uses of each type is closely connected with land quality in each region that may be most suitable for sustainable agriculture development.

Managers normally have an advantage over the market in predicting firm-specific events. This creates information asymmetry between managers of the firm and the market. The purpose of this paper is to investigate the relationship between firm value and information asymmetry in Vietnam. Our data include 202 non-financial companies with 606 firm-year observations collected from the two main stock exchange markets in Vietnam including Hanoi Stock Exchange and Ho Chi Minh Stock Exchange, covering 3 years from 2017-2019. The finding of this study indicates that two variables measuring information asymmetry (ASYDISP, ASYDUM) negatively impact firm value. Besides, control variables such as return on assets, leverage, firm size, and intangible assets are found to have significant effects on firm value.

Objective: Rickettsioses remains one of the most common infectious diseases in Vietnam, the atypical disease’s manifestation often leads to misdiagnosis with other diseases and results in a delayed proper treatment. The study aimed to characterise the clinical and laboratory features of rickettsioses. Subject and method: This was a retrospective cohort study. The clinical and sub-clinical features of rickettsioses were described. All patients admitted to the 108 Military Central Hospital, Hanoi from May 2020 to September 2021. Result: There were 22 patients enrolled into the study and 15/22 (68.2%) hospitalised 5 days after fever onset. The most common clinical features were abrupt fever (100%), headache (100%), myalgia (100%), and skin hyperemia (100%). Some rare signs were recorded: Eschars (9.1%), lymphadenopathy (0%), and rash (4.8%). The laboratory findings showed 95% of the patients with elevated liver transaminases and 51.1% cases with thrombocytopenia. All of the patients were treated with doxycycline and 100% (22/22) fully recovered. The defervescence time was 74.9 ± 38.6 hours and the hospitalisation time was 7.1 ± 1.4 days. Conclusion: The study demonstrated that the appearance of longer than five days fever, severe headache, thrombocytopenia, and elevated liver transaminase could suggest a diagnosis of rickettsioses.

This paper reviews the barriers to ethnic minority women in the development and effectiveness of the credit assistance package for women in poor ethnic minority households in the northern region of Vietnam. Based on data on poor ethnic minority household survey, covering 1685 ethnic households of 4 provinces (Lang Son, Ha Giang, Dien Bien, and Thanh Hoa) in 2018, the analysis emphasized the usefulness of ethnic minority women’s capital and the support of Women’s Union to help members use loans effectively. Since 2003, the Government of Vietnam has launched the solution in poverty reduction strategies and sustainable development in ethnic minority areas in the policy package to support loans for poor minorities. Through the credit support package, ethnic minority women are more proactive in planning production and selling products, with higher incomes from household production activities. Ethnic minority women have overcome many barriers to take initiative in accessing bank credit for household economic development. The credit has been used for development of household economy and improving their position in the family and community, toward sustainable poverty reduction.

Teaching and learning English as a foreign language in a non-native community poses a lot of challenges to both teachers and students. While it is commonly shared that in-class learning does not guarantee the success of the learning, the need for the extension of learning opportunities beyond the class has been remarkably increasing, encouraging English educators to create an environment for English learning beyond the class door. This study aims to set up such environment for non-English majors at Thai Nguyen University of Education, Vietnam. A series of out-of-class English activities were conducted during October 2020 to May 2021 for non-English majors at the University. 200 students joined the study as questionnaire respondents in two phases (before and after the implement of the activities) and 10 students were selected for focus group interview. Results revealed that the majority of the students believed in-class English learning were insufficient for their demands and needs and thus expected similar activities should be carried out beyond the class. The research would be a significant case study to illustrate that efforts to include out-of-class activities in the learning process should be encouraged for the development of an extended language learning environment for the benefits of the students in places where English is largely limited within the classroom walls.

The study aims to evaluate factors affecting the quality of fishery public services in Vietnam’s coastal areas and islands through the level of resident satisfaction. The study interviewed 477 households directly and obtained 450 valid survey forms. The data is collected through surveys in 5 representative localities of the coastal areas and islands including Thai Binh, Nghe An, Binh Dinh, Kien Giang, and Ca Mau provinces and are processed by descriptive statistics, Cronbach’s alpha, exploratory factor analysis, correlation analysis, and regression analysis. The results show that the factor with the lowest rating in fishery public services is assurance. Public utilities have lower quality assessment scores than public non-business services and public administration services.

The study is carried out to analyze the impact of HRM practices on job satisfaction, organizational commitment, and turnover intention of officers working at State agencies in the fisheries sector on the Northern Coast. From the data provided by 350 officers, the structural equation model was applied to evaluate the impact of HRM practices on job satisfaction, organizational commitment, and turnover intention. The results showed a positive relationship between HRM practices and job satisfaction, and organizational commitment. In addition, HRM practices, job satisfaction, and organizational commitment have an inverse correlation with the turnover intention of officers. Moreover, job satisfaction has a positive impact on organizational commitment. The result of the study suggests some important implications for State agencies in the fisheries sector in the Northern Coast to increase job satisfaction, and organizational commitment and reduce turnover intention.

This study examines factors affecting resident satisfaction of the quality of fishery public services. The data collected from 398 interviewees living in Quang Ngai and Binh Dinh provinces are processed with descriptive statistics, Cronbach's alpha, Exploratory Factor Analysis (EFA), and multivariate regression analysis. It is indicated in the research that there are six factors affecting resident satisfaction of the quality of fishery public services including: i) empathy; ii) tangibles; iii) reliability; iv) responsiveness; v) assurance; and vi) transparence. Based on the research results, a number of solutions have been proposed so as to improve resident satisfaction of the quality of fishery public services.