The Experts below are selected from a list of 1986 Experts worldwide ranked by ideXlab platform
Russell D. Gray - One of the best experts on this subject based on the ideXlab platform.
-
new caledonian crows corvus moneduloides attend to barb presence during pandanus tool manufacture and use
Behaviour, 2015Co-Authors: Brenna Knaebe, Alex H Taylor, Rachael Miller, Russell D. GrayAbstract:New Caledonian crows craft wooden hook tools and incorporate naturally occurring barbs into the leaf tools that they manufacture. This raises the question as to whether, or to what degree, these birds are sensitive to the hooks on their hooked and barbed tools. Past research in this area has provided equivocal results. We tested whether New Caledonian crows attend to the presence and orientation of barbs on pandanus leaves and tools during tool manufacture and selection tasks. Our results show that New Caledonian crows attend to barb presence during both pandanus tool manufacture and use, but do not attend to barb direction during pandanus tool use. We conclude that task context, the time and energetic costs of attending to barbs, relative foraging efficiency, and different experimental designs may influence whether, and to what degree, NC crows attend to pandanus barbs.
-
The development of pandanus tool manufacture in wild New Caledonian crows
Behaviour, 2010Co-Authors: Jennifer C. Holzhaider, Gavin R. Hunt, Russell D. GrayAbstract:New Caledonian crows have remarkably complex tool manufacturing abilities. Here we document the ontogeny of pandanus tool manufacture in wild NC crows. Our results show that the development of wide pandanus tool manufacture is a lengthy process comparable to the development of tool use in primates. Juveniles pass through four main stages of tool manufacture before they acquire adult-like proficiency. By 10 to 12 months of age most juveniles can manufacture tools with adult-like competency, but adult-like speed in manufacture and tool use is only reached in their second year. Whilst individual trial and error learning appears to play a major role in juveniles' development of pandanus tool skills, this development takes place in an environment scaffolded by parental birds. Juveniles stay close to their parents for their first year and have ample opportunity to observe parental tool manufacture and use. Parents influence the juveniles' early learning by leading them to Pandanus sp. trees where they provide discarded tools for early tool use. Exposure to parental tools might help juveniles form a mental template of functional tool design and, thus, facilitate the faithful transmission of local design traditions.
-
do wild new caledonian crows corvus moneduloides attend to the functional properties of their tools
Animal Cognition, 2008Co-Authors: Jennifer C. Holzhaider, Gavin R. Hunt, Victoria M Campbell, Russell D. GrayAbstract:New Caledonian crows are the most proficient non-hominin tool manufacturers but the cognition behind their remarkable skills remains largely unknown. Here we investigate if they attend to the functional properties of the tools that they routinely use in the wild. Pandanus tools have natural barbs along one edge that enable them to function as hooking implements when the barbs face backwards from the working tip. In experiment 1 we presented eight crows with either a non-functional (‘upside-down’) or a functional pandanus tool in a baited hole. Four of the crows never flipped the tools. The behaviour of the four flipping birds suggested that they had a strategy of flipping a tool when it was not working. Observations of two of the eight crows picking up pandanus tools at feeding tables in the wild supported the lack of attention to barb direction. In experiment 2 we gave six of the eight crows a choice of either a barbed or a barbless pandanus tool. Five of the crows chose tools at random, which further supported the findings in experiment 1 that the crows paid little or no attention to the barbs. In contrast, a third experiment found that seven out of eight crows flipped non-functional stick tools significantly more than functional ones. Our findings indicate that the crows do not consistently attend to the presence or orientation of barbs on pandanus tools. Successful pandanus tool use in the wild seems to rely on behavioural strategies formed through associative learning, including procedural knowledge about the sequence of operations required to make a successful pandanus tool.
-
cognitive requirements for tool use by new caledonian crows corvus moneduloides
New Zealand Journal of Zoology, 2007Co-Authors: Gavin R. Hunt, C Lambert, Russell D. GrayAbstract:Cumulative technological evolution has been suggested to explain the existence of different pandanus tool designs manufactured by New Caledonian crows. Circumstantial evidence from the distribution...
-
Design complexity and strength of laterality are correlated in New Caledonian crows' pandanus tool manufacture
Proceedings. Biological sciences, 2006Co-Authors: Gavin R. Hunt, Michael C. Corballis, Russell D. GrayAbstract:Population-level laterality is generally considered to reflect functional brain specialization. Consequently, the strength of population-level laterality in manipulatory tasks is predicted to positively correlate with task complexity. This relationship has not been investigated in tool manufacture. Here, we report the correlation between strength of laterality and design complexity in the manufacture of New Caledonian crows' three pandanus tool designs: wide, narrow and stepped designs. We documented indirect evidence of over 5800 tool manufactures on 1232 pandanus trees at 23 sites. We found that the strength of laterality in tool manufacture was correlated with design complexity in three ways: (i) the strongest effect size among the population-level edge biases for each design was for the more complex, stepped design, (ii) the strength of laterality at individual sites was on average greater for the stepped design than it was for the simpler wide and narrow, non-stepped designs, and (iii) there was a positive, but non-significant, trend for a correlation between the strength of laterality and the number of steps on a stepped tool. These three aspects together indicate that greater design complexity generally elicits stronger lateralization of crows' pandanus tool manufacture.
Wuryandari Wahyu - One of the best experts on this subject based on the ideXlab platform.
-
Aktivitas Antifungi Seduhan Daun Pandan Wangi (Pandanus amaryllifolius Rxb.) Terhadap Pertumbuhan Candida albicans dengan Metode Sumuran
2019Co-Authors: Tias, Presti Dwi Ayuning, Wuryandari WahyuAbstract:Tias, Presti Dwi Ayuning. 2019. Aktivitas Antifungi Seduhan Daun Pandan Wangi (Pandanus amaryllifolius Roxb.) Terhadap Pertumbuhan Candida albicans dengan Metode Sumuran. Karya Tulis Ilmiah Akademi Farmasi Putra Indonesia Malang. Pembimbing: Dra Wahyu Wuryandari, M.Pd. Kata Kunci: Antifungi, Candida albicans, Daun Pandan Wangi. Pandan wangi merupakan tanaman yang sering dimanfaatkan daunnya sebagai bahan tambahan makanan, umumnya sebagai pemberi aroma. Kandungan senyawa kimia berupa tannin, saponin, alkoloid, flavonoid, pada tumbuhan pandan wangi memiliki aktivitas antifungi. Secara empiris Daun Pandan Wangi (Pandanus amaryllifolius Roxb.) digunakan sebagai obat keputihan dengan cara direbus. Keputihan salah satu permasalahan yang meresahkan kaum wanita, penyebab keputihan yang sering terjadi disebabkan oleh adanya jamur Candida albicans. Penelitian ini bertujuan untuk mengetahui aktivitas antifungi dengan perbedaan waktu penyeduhan seduhan daun pandan wangi (Pandanus amaryllifolius Roxb.) terhadap pertumbuhan Candida albicans. Metode penelitian ini menggunakan metode sumuran pada media SDA dengan perlakuan variasi waktu penyeduhan 15 menit, 30 menit dan 45 menit. Dari hasil penelitian menunjukan penyeduhan 45 menit Daun Pandan Wangi (Pandanus amaryllifolius Roxb.) memberikan aktifitas antifungi terhadap pertumbuhan Candida albicans dengan membentuk zona bening atau zona hambat sebesar 4,3 mm yang masuk dalam kategori lemah dalam aktifitas antifungi
-
AKTIVITAS ANTIFUNGI REBUSAN DAUN PANDAN WANGI (Pandanus amaryllifolius Roxb.) TERHADAP PERTUMBUHAN candida albicans DENGAN VARIASI LAMA WAKTU REBUSAN
2019Co-Authors: Dewi, Sari Ulfiana, Wuryandari WahyuAbstract:Kandidiasis merupakan infeksi yang disebabkan oleh spesies Candida. Spesies Candida yang dianggap paling patogen yaitu Candida albicans. Secara empiris rebusan daun pandan wangi (Pandanus amaryllifolius Roxb) digunakan masyarakat untuk mengobati infeksi Candida albicans. Penelitian menunjukkan bahwa senyawa metabolit sekunder daun pandan wangi memiliki pengaruh terhadap pertumbuhan Candida albicans. Penelitian ini bertujuan untuk mengetahui aktivitas antifungi rebusan daun pandan wangi (Pandanus amaryllifolius Roxb.) terhadap pertumbuhan Candida albicans dengan variasi lama waktu rebusan. Uji aktivitas lama waktu rebusan daun pandan wangi dilakukan menggunakan metode difusi sumuran dengan variasi rebusan mendidih 0 menit, mendidih 30 menit, dan mendidih 60 menit. Variasi rebusan mendidih 0 menit membentuk zona hambat dengan rata-rata 2,5 mm, dan untuk variasi rebusan mendidih menit 30 dan mendidih 60 menit tidak membentuk zona hambat. Berdasarkan hasil peneltian yang telah dilakukan dapat disimpulkan bahwa terdapat aktivitas antifungi daun pandan wangi (Pandanus amaryllifolius Roxb) terhadap pertumbuhan Candida albicans dengan variasi lama waktu rebusan pada variasi mendidih 0 menit. Kata kunci : Candida albicans. Daun Pandan Wangi, Metabolit Sekunder dan Zona Hambat
-
AKTIVITAS ANTIFUNGI PERASAN DAUN PANDAN WANGI (Pandanus amaryllifolius Roxb.) TERHADAP PERTUMBUHAN Candida albicans
2019Co-Authors: Nanda, Nita Fentia, Wuryandari WahyuAbstract:Keputihan merupakan gejala yang paling sering dialami oleh sebagian besar wanita. Penyebab keputihan yang sering terjadi disebabkan oleh jamur yang sifatnya parasit yaitu Candida albicans. Salah satu pengobatan tradisional menggunakan daun pandan wangi (Pandanus amaryllifolius Roxb.) untuk mengobati keputihan dengan cara direbus. Penelitian ini bertujuan untuk mengetahui aktivitas antifungi perasan daun pandan wangi terhadap pertumbuhan Candida albicans. Pemilihan metode perasan karena dinilai praktis dan mudah dilakukan oleh masyarakat. Manfaat dari penelitian ini dapat memberikan informasi kepada masyarakat tentang khasiat daun pandan wangi. Penelitian ini menggunakan metode difusi sumuran pada media SDA. Hasil identifikasi fitokimia secara kualitatif terhadap empat senyawa yaitu: flavonoid, saponin, tanin dengan hasil positif dan alkaloid dengan hasil negatif. Hasil identifikasi fungi uji Candida albicans berwarna krem serta berbentuk oval. Perasan daun pandan wangi (Pandanus amaryllifolius Roxb.) tidak mempunyai aktivitas antifungi terhadap pertumbuhan Candida albicans Kata Kunci: Antifungi, Daun Pandan Wangi, Candida albicans
Gavin R. Hunt - One of the best experts on this subject based on the ideXlab platform.
-
new caledonian crows corvus moneduloides pandanus tool designs diversification or independent invention
The Wilson Journal of Ornithology, 2014Co-Authors: Gavin R. HuntAbstract:Abstract New Caledonian Crows (Corvus moneduloides) manufacture the most complex foraging tools used by nonhuman animals. Not only do they shape multiple tool designs of different complexity out of raw material using distinct, design-specific manufacture techniques, they are the only species to incorporate hook technology. The three different hook tool designs that they cut out of barbed Pandanus spp. leaves are suggested to have evolved by a process of diversification through cumulative changes rather than independent invention. Here, I describe three examples of an oversized version of the so-called ‘narrow’ pandanus tool design in an area where narrow tools are also made. My observation of the way a crow used one of these oversized tools in the wild suggests that they may be efficient for foraging in especially deep probe sites. The co-occurrence of two different designs originating from a very similar manufacture technique is consistent with diversification. Furthermore, qualitative data suggest that ...
-
The development of pandanus tool manufacture in wild New Caledonian crows
Behaviour, 2010Co-Authors: Jennifer C. Holzhaider, Gavin R. Hunt, Russell D. GrayAbstract:New Caledonian crows have remarkably complex tool manufacturing abilities. Here we document the ontogeny of pandanus tool manufacture in wild NC crows. Our results show that the development of wide pandanus tool manufacture is a lengthy process comparable to the development of tool use in primates. Juveniles pass through four main stages of tool manufacture before they acquire adult-like proficiency. By 10 to 12 months of age most juveniles can manufacture tools with adult-like competency, but adult-like speed in manufacture and tool use is only reached in their second year. Whilst individual trial and error learning appears to play a major role in juveniles' development of pandanus tool skills, this development takes place in an environment scaffolded by parental birds. Juveniles stay close to their parents for their first year and have ample opportunity to observe parental tool manufacture and use. Parents influence the juveniles' early learning by leading them to Pandanus sp. trees where they provide discarded tools for early tool use. Exposure to parental tools might help juveniles form a mental template of functional tool design and, thus, facilitate the faithful transmission of local design traditions.
-
do wild new caledonian crows corvus moneduloides attend to the functional properties of their tools
Animal Cognition, 2008Co-Authors: Jennifer C. Holzhaider, Gavin R. Hunt, Victoria M Campbell, Russell D. GrayAbstract:New Caledonian crows are the most proficient non-hominin tool manufacturers but the cognition behind their remarkable skills remains largely unknown. Here we investigate if they attend to the functional properties of the tools that they routinely use in the wild. Pandanus tools have natural barbs along one edge that enable them to function as hooking implements when the barbs face backwards from the working tip. In experiment 1 we presented eight crows with either a non-functional (‘upside-down’) or a functional pandanus tool in a baited hole. Four of the crows never flipped the tools. The behaviour of the four flipping birds suggested that they had a strategy of flipping a tool when it was not working. Observations of two of the eight crows picking up pandanus tools at feeding tables in the wild supported the lack of attention to barb direction. In experiment 2 we gave six of the eight crows a choice of either a barbed or a barbless pandanus tool. Five of the crows chose tools at random, which further supported the findings in experiment 1 that the crows paid little or no attention to the barbs. In contrast, a third experiment found that seven out of eight crows flipped non-functional stick tools significantly more than functional ones. Our findings indicate that the crows do not consistently attend to the presence or orientation of barbs on pandanus tools. Successful pandanus tool use in the wild seems to rely on behavioural strategies formed through associative learning, including procedural knowledge about the sequence of operations required to make a successful pandanus tool.
-
cognitive requirements for tool use by new caledonian crows corvus moneduloides
New Zealand Journal of Zoology, 2007Co-Authors: Gavin R. Hunt, C Lambert, Russell D. GrayAbstract:Cumulative technological evolution has been suggested to explain the existence of different pandanus tool designs manufactured by New Caledonian crows. Circumstantial evidence from the distribution...
-
Design complexity and strength of laterality are correlated in New Caledonian crows' pandanus tool manufacture
Proceedings. Biological sciences, 2006Co-Authors: Gavin R. Hunt, Michael C. Corballis, Russell D. GrayAbstract:Population-level laterality is generally considered to reflect functional brain specialization. Consequently, the strength of population-level laterality in manipulatory tasks is predicted to positively correlate with task complexity. This relationship has not been investigated in tool manufacture. Here, we report the correlation between strength of laterality and design complexity in the manufacture of New Caledonian crows' three pandanus tool designs: wide, narrow and stepped designs. We documented indirect evidence of over 5800 tool manufactures on 1232 pandanus trees at 23 sites. We found that the strength of laterality in tool manufacture was correlated with design complexity in three ways: (i) the strongest effect size among the population-level edge biases for each design was for the more complex, stepped design, (ii) the strength of laterality at individual sites was on average greater for the stepped design than it was for the simpler wide and narrow, non-stepped designs, and (iii) there was a positive, but non-significant, trend for a correlation between the strength of laterality and the number of steps on a stepped tool. These three aspects together indicate that greater design complexity generally elicits stronger lateralization of crows' pandanus tool manufacture.
Maribel G Nonato - One of the best experts on this subject based on the ideXlab platform.
-
isolation and absolute configuration determination of alkaloids from pandanus amaryllifolius
Tetrahedron, 2017Co-Authors: Yuanbin Cheng, Maribel G Nonato, Yu Chi Tsai, Shu Li Chen, Mohamed Elshazly, Fang Rong ChangAbstract:Abstract Seven new alkaloids belonging to three typical classes, isolated from an ethanolic extract of Pandanus amaryllifolius , were applied to establish the models in structural elucidation. The first type [pandanusines A and B ( 1 and 2 )] was applied to alkaloids with a diazaspirocyclic ring system. The absolute stereochemistry of aminal carbon is determined by analysis of J -based configuration analysis and circular dichroism spectroscopy, which has never been revealed before. The second type [pandalizines C–E ( 3 – 5 )], the stereochemistry of unusual indolizinone with chiral hydroxyl substitutions were determined by circular dichroism spectroscopy and vibrational circular dichroism experiments. The last type [norpandamarilactonines C and D ( 6 and 7 )], a comparing model in determination of diastereomers of pyrrolidinyl α , β -unsaturated γ -lactone alkaloids was established. Our study provides solutions for a challenging subject in stereochemistry determination for three different types of Pandanus alkaloids.
-
isolation of pandamarilactonine h from the roots of pandanus amaryllifolius and synthesis of epi pandamarilactonine h
Journal of Natural Products, 2010Co-Authors: Mario A Tan, Maribel G Nonato, Mariko Kitajima, Noriyuki Kogure, Hiromitsu TakayamaAbstract:A new alkaloid (1a), named pandamarilactonine-H, which possesses a methyl-2-(pyrrolidin-2-yl)acetate function, was isolated from the roots of Pandanus amaryllifolius. Eleven known alkaloids were also isolated. Unambiguous assignment of the structure of 1a, including the absolute configuration, was accomplished by spectroscopic analysis and total synthesis of its enantiomer.
-
isolation and total syntheses of two new alkaloids dubiusamines a and b from pandanus dubius
Tetrahedron, 2010Co-Authors: Mario A Tan, Maribel G Nonato, Mariko Kitajima, Noriyuki Kogure, Hiromitsu TakayamaAbstract:Chemical investigation of the crude base of Pandanus dubius led to the isolation of two new alkaloids, dubiusamine-A (1) and dubiusamine-B (2). The structures of the two alkaloids including their absolute configuration were unambiguously confirmed by 1D and 2D NMR analysis and asymmetric total synthesis.
-
isolation and characterization of two new alkaloids norpandamarilactonine a and b from pandanus amaryllifolius by spectroscopic and synthetic methods
Journal of Natural Products, 2001Co-Authors: Hiromitsu Takayama, Tomotake Ichikawa, Mariko Kitajima, Maribel G Nonato, Norio AimiAbstract:Two new alkaloids, norpandamarilactonine-A (1) and -B (2), which have a pyrrolidinyl-α,β-unsaturated γ-lactone moiety as in the known pandamarilactonine alkaloids, were isolated from the leaves of Pandanus amaryllifolius. Their structures were determined by spectroscopic analysis and total synthesis.
-
a new alkaloid pandanamine finding of an anticipated biogenetic intermediate in pandanus amaryllifolius roxb
Tetrahedron Letters, 2001Co-Authors: Hiromitsu Takayama, Tomotake Ichikawa, Mariko Kitajima, Norio Aimi, Dazy Lopez, Maribel G NonatoAbstract:A novel alkaloid having a symmetrical structure, which was anticipated to be a biogenetic precursor of pandamarilactonines and pandamarilactone-1, was found in the fresh leaves of Pandanus amaryllifolius Roxb.
Eletskaya Maria - One of the best experts on this subject based on the ideXlab platform.
-
FIGURE 6 in A new species of the pandalid shrimp genus Pandalus (Crustacea: Decapoda: Caridea) from the Sea of Okhotsk off eastern Sakhalin, Russian Far East
2018Co-Authors: Komai Tomoyuki, Eletskaya MariaAbstract:FIGURE 6. Photographs showing coloration in fresh. A, Pandalus ivanovi n. sp., paratype, female (CL 31.4 mm; CBM- ZC 9222); B, Pandalus hypsinotus Brandt, 1851, female (CL 33.8 mm; CBM-ZC 9473), Canada
-
FIGURE 1. Pandalus ivanovi n in A new species of the pandalid shrimp genus Pandalus (Crustacea: Decapoda: Caridea) from the Sea of Okhotsk off eastern Sakhalin, Russian Far East
2018Co-Authors: Komai Tomoyuki, Eletskaya MariaAbstract:FIGURE 1. Pandalus ivanovi n. sp. Holotype, female (CL 28.4 mm; CBM-ZC 9221), habitus in lateral view, in preservative
-
FIGURE 7. Pandalus hypsinotus Brandt, 1851 in A new species of the pandalid shrimp genus Pandalus (Crustacea: Decapoda: Caridea) from the Sea of Okhotsk off eastern Sakhalin, Russian Far East
2018Co-Authors: Komai Tomoyuki, Eletskaya MariaAbstract:FIGURE 7. Pandalus hypsinotus Brandt, 1851. Syntypes (ZISP 1453). A, four specimens removed from jar; B, one of the syntypes; C, largest syntype (CL about 38.0 mm)
-
FIGURE 8 in A new species of the pandalid shrimp genus Pandalus (Crustacea: Decapoda: Caridea) from the Sea of Okhotsk off eastern Sakhalin, Russian Far East
2018Co-Authors: Komai Tomoyuki, Eletskaya MariaAbstract:FIGURE 8. Scatter plot of the relative length of the rostrum (indicated by rostral length / carapace length against carapace length) between Pandalus ivanovi n. sp. and P. hypsinotus Brandt, 1851
-
FIGURE 3. Pandalus ivanovi n in A new species of the pandalid shrimp genus Pandalus (Crustacea: Decapoda: Caridea) from the Sea of Okhotsk off eastern Sakhalin, Russian Far East
2018Co-Authors: Komai Tomoyuki, Eletskaya MariaAbstract:FIGURE 3. Pandalus ivanovi n. sp. Holotype, female (CL 28.4 mm; CBM-ZC 9221), thoracic appendages in lateral view. A, left third maxilliped; B, left first pereopod; C, left second pereopod; D, right second pereopod; E, left third pereopod; F, left fourth pereopod; G, left fifth pereopod. Scale bar: 5 mm
