1,721,066 research outputs found
Herdmania Lahille 1888
No full textHerdmania sp. All tiny juveniles less than 1 cm. #1214; #1230A, three; #3728C; #3827E, on Polycarpa argentata.Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 29, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/454784
Perophora Wiegmann 1835
No full textPerophora sp. #4630B, small colony, immature.Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 18, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/454784
Microcosmus Heller 1877
No full textMicrocosmus sp. #4651, tiny; reddish tunic. Size fully relaxed 1.2 cm in length, 0.8 cm wide at base of red-striped siphons. Gonad not well developed.Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 29, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/454784
Sorptivity of water in sound and demineralised enamel / Gan Siew Chen
Get PDFInitial caries which present clinically as white spot lesions typically start with
demineralisation of the enamel surface which causes an increase in surface porosity. At
the same time, non-porous highly mineralised surface layer which is commonly known
as “surface layer” progressively forms on the enamel. If demineralisation continues, the
surface layer breaks down and the enamel surface becomes porous again. The intermittent
presence of the surface layer in the cycle of remineralisation and demineralisation could
be the reason for the lack of conclusive evidence of success in remineralisation therapies.
Remineralisation materials may not be penetrating the surface efficiently when the
surface layer is present. There are currently no clinical methods to determine the porosity
of the enamel surface. If porosity and presence of the highly mineralised surface layer on
white spot lesions can be determined, the success of remineralisation therapy can be
improved. In this research, it is hypothesised that the measured rate of absorption using
sorptivity on sound and demineralised enamel surface can be used to determine the level
of porosity and presence of a surface layer on the enamel surface. The aim of this thesis
is to determine the association between sorptivity of water and the state of mineralisation
of surface enamel by first, exploring the viability of sorptivity as a tool to measure surface
absorption rate on sound and demineralised enamel. Secondly, is to explore the
associations between sorptivity with mineral density on sound and demineralised enamel
surface. A 0.7 microliter droplet of water was placed with a micropipette on the exposed
enamel of 96 teeth (192 test sites) which had undergone various duration of pH cycling
(GS- group of specimens that did not undergo pH cycling, G7- group of specimens that
underwent 7 days pH cycling, G14- group of specimens that underwent 14 days pH
cycling, G21- group of specimens that underwent 21 days pH cycling, G28- group of
specimens that underwent 28 days pH cycling and G35- group of specimens that
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underwent 35 days pH cycling). Thorlabs Swept-Source OCT system (OCS 1300SS) was
used to measure the height of the drop every 10 seconds for 2 minutes. Sorptivity of each
test site was then computed after accounting for evaporation. Total Delta Z of grey scale
value from 10µm (TDZ10) to 50µm (TDZ50) was calculated using images taken with
microcomputed tomography (Micro- CT). Integrated reflectivity is measured from 10 µm
(IR10) to 50 µm (IR500 using images taken with OCT1300SS. SEM, Micro-CT,
photography and stereo microscope images were taken to provide qualitative analysis.
SPSS 25 (IBM) with One-way ANOVA, post-hoc Tukey and Dunnett’s T3 was used to
compare means and Bivariate (Pearson) Correlations was used to compare 2 variables.
Results show that mean sorptivity increased from GS to G14 and from G21 to G35,
juxtaposed by a decline between G14 and G21. One-Way ANOVA showed significant
difference of mean sorptivity between groups (p<0.0). Mean TDZ10 and mean IR10 seem
to project the same relationship between groups. This appears to confirm the cycle of
remineralisation and demineralisation and the presence of a surface layer in G21. The
most significant correlation was found between sorptivity and TDZ10 with Pearson
Correlation coefficient of 0.461. IR10 show significant correlations with sorptivity when
results from GS, G7, G14 and G21 were chosen with Pearson correlation coefficient of
0.275. Qualitatively, the presence of a surface layer in many test sites in G21 explains the
reason for low mean sorptivity value for this group. In conclusion, these tests have shown
for the first time that sorptivity of water is linearly and inversely correlated with the state
of mineralisation at the surface of enamel. Sorptivity can be used to determine the
presence of a surface layer
Didemnidae Giard 1872
No full textFamily Didemnidae Giard, 1872 Most of the didemnids remain unidentified and examined only externally, but every specimen collected is included in Supplement 1 with its identifying number.Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 5, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/454784
Pyuridae Hartmeyer 1908
No full textUnidentified Pyuridae #3858A, small individual, 1 cm across out of tunic. Tunic covered with very long slender tunic spines/tubercles. Siphons striped red and white.Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 31, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/454784
Aplidiopsis Lahille 1890
No full textAplidiopsis sp. #4636, tan cushion, tunic light brown in fixative, translucent, pale yellowish zooids visible through tunic; zooids very contracted, not possible to count rows of stigmata. No branchial papillae (characteristic of Polyclinum spp.), stomach smooth, no larvae.Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 11, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/454784
Botrylloides sp. Milne-Edwards 1841
No full textBotrylloides sp. #3795, zooids orange in life, brown in fixative with many small dark red pigment spots on body wall. Second row of stigmata incomplete. Zooids well relaxed; atrial languet brown, flat ended, huge, in some zooids almost as long as the entire zooid. Nine stomach lobes, with expanded bulbous distal ends. No discernible caecum. No gonads or larvae.Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 19, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/454784
FIGURE 4. A–D in Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop
No full textFIGURE 4. A–D: Eudistoma laysani. A: whole living colony 3 cm across; B: one head; C: unhatched tadpole 800 µm in length; D: one head of preserved colony. E: Eudistoma regina, part of large colony; F: Aplidium cf. grisiatum colony 1.5 cm in width; G–H: Pseudodistoma fragile. G: whole living colony 4 cm across; H: single zooid 8 mm in length, somewhat contracted. Scale bar: E, 0.4 cm.Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 12, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/454784
Eusynstyela Michaelsen 1904
No full textEusynstyela sp. #3858B, attached to #3858A, a juvenile pyurid. Only a few zooids, separated from each other by stolons. Single row of gonads on each side, with two elongate testes in each gonad. Seven gonads on one side, 11 on the other side.Published as part of Lambert, Gretchen, Lee, Serina Siew-Chen & Teo, Serena Lay-Ming, 2021, Ascidians collected during the 2013 Singapore Strait International Marine Biodiversity Workshop, pp. 1-38 in Zootaxa 4933 (1) on page 20, DOI: 10.11646/zootaxa.4933.1.1, http://zenodo.org/record/454784
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