135,203 research outputs found
Fig. 1 in On the status of some species of Cheirostylis Blume (Orchidaceae) from India
No full textFig. 1. – Comparison plate: 'Cheirostylis chinensis var. glabra Bhaumik & M. K. Pathak'. A. Labellum; B. Petal; C. Column with anther-cap – Cheirostylis moniliformis (Griff.) Seidenf.; D-E. Labellum; F. Petal; G. Column – 'Cheirostylis seidenfadeniana C. S. Kumar & F. N. Rasm.'; H. Labellum – Cheirostylis parvifolia Lindl.; I-J. Labellum. [A-C: after BHAUMIK & PATHAK, 2006; D, F-G: A. Bhattacharjee 34819 A, CL; E: A. Bhattacharjee 34819 B, CAL; H: after SATHISH KUMR & RASMUSSEN, 1987; I: Sathish Kumar s.n., TBGT, spirit; J: A. Bhattacharjee 38142 A, CAL]Published as part of Bhattacharjee, Avishek, 2012, On the status of some species of Cheirostylis Blume (Orchidaceae) from India, pp. 31-35 in Candollea 67 (1) on page 33, DOI: 10.15553/c2012v671a3, http://zenodo.org/record/570865
FIGURE 3 in Gastrochilus pseudocalceolaris, a new species of epiphytic orchid from India
No full textFIGURE 3. Labellum of – A, B. Gastrochilus calceolaris (Buch.-Ham. ex Sm.) D. Don; C. G. acaulis (Lindl.) Kuntze; D, E. G. pseudocalceolaris S. Dey, L. Phom, Av. Bhattacharjee, Moaakum & K. Eshuo.Published as part of Dey, Santanu, Phom, Limamanen, Bhattacharjee, Avishek & Eshuo, Kazhuhrii, 2022, Gastrochilus pseudocalceolaris, a new species of epiphytic orchid from India, pp. 295-300 in Phytotaxa 574 (4) on page 298, DOI: 10.11646/phytotaxa.574.4.5, http://zenodo.org/record/738910
Fig. 2 in On the status of some species of Cheirostylis Blume (Orchidaceae) from India
No full textFig. 2. – 'Cheirostylis munnacampensis A. N. Rao'. A. Flower; B. Petal; C. Labellum; D. Column with anther-cap – Cheirostylis yunnanensis Rolfe; E. Flower; F-G. Petal; H. Labellum (partly fragmented); I. Portion of hypochile with appendages (magnified); J. Column. [A-D: after RO, 1988; E-J: T. K. Paul 43698, CAL, dissected from dry and pressed specimen]Published as part of Bhattacharjee, Avishek, 2012, On the status of some species of Cheirostylis Blume (Orchidaceae) from India, pp. 31-35 in Candollea 67 (1) on page 35, DOI: 10.15553/c2012v671a3, http://zenodo.org/record/570865
Theory of tunneling conductance of graphene normal metal-insulator-superconductor junctions
No full textWe calculate the tunneling conductance of a graphene normal metal-insulator-superconductor (NIS) junction with a barrier of thickness d and with an arbitrary voltage V0 applied across the barrier region. We demonstrate that the tunneling conductance of such a NIS junction is an oscillatory function of both d and V0. We also show that the periodicity and amplitude of such oscillations deviate from their universal values in the thin barrier limit as obtained in an earlier work [ S. Bhattacharjee and K. Sengupta Phys. Rev. Lett. 97 217001 (2006)] and become a function of the applied voltage V0. Our results reproduce the earlier results on tunneling conductance of such junctions in the thin [ S. Bhattacharjee and K. Sengupta Phys. Rev. Lett. 97 217001 (2006)] and zero [ C. W. J. Beenakker Phys. Rev. Lett. 97 067007 (2006)] barrier limits as special limiting cases. We discuss the experimental relevance of our results
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
RBECA: A regularized Bi-partitioned entropy component analysis for human face recognition
No full textThis paper presents a novel approach for Human Face Recognition, namely Regularized Bi-partitioned Entropy Component Analysis (RBECA). This conservative approach regularizes the kernel entropy components by deterring the noise and affecting the lower entropy regions area, making the method robust to noise. The kernel feature space, formed by the kernel entropy component analysis (KECA), is divided into two partitions: the High Entropy Space (HES) and the Low Entropy Space (LES). The noise-laden low entropy spectrum is regularized by predicting entropy values obtained from the information-filled High Entropy Spectrum. The corresponding projection vectors are adjusted accordingly. A null space, comprising the negligible information and many dimensions, is eliminated using a Golden Search minimization function at two stages. The method retains the maximum entropy property and high recognition accuracy while using the optimum number of features. This resultant feature vector is classified using the cosine similarity measure. The algorithm is successfully tested on several benchmark databases like AR, FERET, FRAV2D, and LFW, using standard protocols and compared with other competitive methods. The proposed method achieves much better recognition accuracy than other well-known methods like PCA, ICA, KPCA, KECA, LGBP, ERE, etc., in all considered cases. Moreover, we have also proposed a CNN for the comparative analysis. For unbiased or fair performance evaluation, the sensitivity and specificity are also reported
Theory of tunneling conductance of graphene normal metal-insulator-superconductor junctions
No full textWe calculate the tunneling conductance of a graphene normal metal-insulator-superconductor (NIS) junction with a barrier of thickness d and with an arbitrary voltage applied across the barrier region. We demonstrate that the tunneling conductance of such a NIS junction is an oscillatory function of both d and . We also show that the periodicity and amplitude of such oscillations deviate from their universal values in the thin barrier limit as obtained in an earlier work [S. Bhattacharjee and K. Sengupta, Phys. Rev. Lett. 97, 217001 (2006)] and become a function of the applied voltage . Our results reproduce the earlier results on tunneling conductance of such junctions in the thin [S. Bhattacharjee and K. Sengupta, Phys. Rev. Lett. 97, 217001 (2006)] and zero [C. W. J. Beenakker, Phys. Rev. Lett. 97, 067007 (2006)] barrier limits as special limiting cases. We discuss the experimental relevance of our results
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Third EuCAPT Annual Symposium
No full textBrown dwarfs (BDs) are celestial objects representing the link between the least massive main-sequence stars and giant gas planets. I will present a recent analysis (Bhattacharjee et al.,2023) where consider a sample of nine nearby ( 11 pc distance), cold and old BDs and look for gamma-ray signal from the direction of these objects using 13 years of \textit{Fermi}-LAT data. In the absence of any gamma-ray excess, we set 95\% confidence level upper limits on the gamma-ray flux with a binned-likelihood approach.
I will then show how this null result can be used to constrain particle dark matter (DM). If the DM of the universe is constituted of particles with non-negligible couplings to the standard model, BDs may efficiently accumulate them through scatterings. DM particles eventually thermalize and can annihilate into light, long-lived, mediators which later decay into photons outside the BD.
Within this framework, we set a stacked upper limit on the DM-nucleon elastic scattering cross section at the level cm for DM masses below 10 GeV. Our limits are comparable to similar bounds from the capture of DM particles in celestial objects but have the advantage of covering a larger portion of the parameter space in mediator decay length and DM mass and being less affected by DM modeling uncertainties.
Reference:
Bhattacharjee et al.,2023 - ``Gamma-ray flux limits from brown dwarfs: Implications for dark matter annihilating into long-lived mediators'' -Pooja Bhattacharjee, Francesca Calore, and Pasquale Dario Serpico - Phys. Rev. D 107, 043012 – Published 10 February 202
Gastrochilus pseudocalceolaris S. Dey, L. Phom, Av. Bhattacharjee, Moaakum & K. Eshuo 2022, sp. nov.
No full textGastrochilus pseudocalceolaris S. Dey, L. Phom, Av. Bhattacharjee, Moaakum & K. Eshuo, sp. nov. FIGURE 1, 2 Types:— INDIA. Nagaland, Longleng district, Yingyushang Mountain, 1854 m, 7 April 2022, S. Dey 1342 (holotype CAL!, barcode CAL0000217503; isotype CAL!, barcode CAL0000217504) Diagnosis: — Gastrochilus pseudocalceolaris is morphologically allied to G. calceolaris, but differs in having much shorter stem and a labellum-epichile without long, papillose hairs on its adaxial surface, and epichile with shortly erose margins. Description: —Epiphytic, pendent herbs, 12–16 cm long (including leaves). Roots velamenous, up to 12 cm long, thin. Stem 1–3 cm long, 0.5–1 cm thick, internodes clasped with sheathing leaf bases. Leaves 4–5, narrowly oblong to linear-lanceolate, 6–15 × 0.6–2 cm, fleshy, nearly flat, with narrower bases, unequally bifid at apex, sheathing and articulate at base. Inflorescences lateral, 1–2.5 cm long, subumbellate, 4–6-flowered. Floral bracts ovate-triangular, ca. 0.2 × 0.15 cm, much shorter than pedicel plus ovary, pale pinkish-brown, acute to subacute at apex. Flowers 1.7–2.3 cm long, 1.2–1.5 cm across, faintly fragrant; sepals and petals yellowish-green blotched with reddish-brown; hypochile greenish-yellow, spotted with purplish-red; epichile white except the yellow, subtriangular disc near center, blotched with purplish-red; pedicel plus ovary 1.3–1.6 cm long. Sepals subequal, obovate-oblong to obovate-lanceolate, 0.5–0.7 × 0.18–0.24 cm, spreading, obtuse at apex, laterals slightly narrower. Petals obliquely oblong-obovate to oblongspathulate, 0.5–0.65 × 0.18–0.22 cm, spreading, obtuse at apex. Labellum adnate to lower half of column; hypochile cup-shaped, 0.6–0.7 × 0.5–0.6 cm, rim of hypochile forming almost oblique to subvertical front edges with the base of epichile; epichile subreniform to subovate, 0.2–0.25 × 0.4–0.4.8 cm, without any long, papillose hair on adaxial surface, with a few minute blister-like protuberances near central cushion, with a cavity at base of cushion, abaxial surface glabrous, shortly erose at margins. Column 0.2–0.3 cm long. Anther 0.16–0.2 × 0.18–0.2 cm; pollinia 2, ovoidelliptic, 0.07–0.09 × 0.04–0.07 cm, monoporate; stipe linear, 0.14–0.18 cm long, hyaline; viscidium oblong-elliptic, 0.05–0.08 × 0.04–0.06 cm. Capsule ca. 2 × 0.6 cm, with 4 ridges, dark brown in maturity. Flowering & Fruiting: —Both observed in April. Habitat: —On tree trunks and branches in subtropical semi evergreen forest at 1854 m elevation; abundance rare. Distribution: — INDIA: Nagaland (Endemic) Etymology: —The specific epithet is derived from the Greek ‘ pseudo-’ (false) and after ‘ Gastrochilus calceolaris ’ referring to its close similarity with G. calceolaris. Note: —Though Gastrochilus pseudocalceolaris apparently looks alike to G. calceolaris, it can be distinguished by its much shorter stem (1–3 cm long), labellum-epichile without numerous, long, papillose hairs on its adaxial surface, and epichile with shortly erose margins (FIGURE 1, 2, 3 D, E). G. calceolaris is a highly variable species which is reported from Nepal to Hainan and West Malesia (Liu et al. 2019, Govaerts et al. 2022). Bhattacharjee et al. (2021) reported variations (based on freshly collected as well as herbarium-specimens) in G. calceolaris with respect to stem length (4–10 cm long); size of the leaves and nature of apex; number and size of the flowers; size, density and intensity of blotches on perianth; texture and thickness of sepals, petals and labellum; the cupular hypochile with or without a rim at the juncture with the epichile; density and distribution of papillate hairs on epichile; shape and margins of epichile; and presence or absence of purplish spots on the yellow cushion on the epichile. Though in all studied specimens of G. calceolaris, numerous, long, papillose hairs on the epichile are prominent (FIGURE 3 A, B), these are completely lacking in G. pseudocalceolaris and is the most prominent diagnostic character of the new species. Based on morpho-molecular studies, Liu et al. (2019) separated two new species from G. calceolaris and described G. changjiangensis Q. Liu & M.Z. Huang and G. zhenyuanensis Q. Liu & D.P. Ye., but they did not report any specimen of G. calceolaris without numerous, long, papillose hairs. Gastrochilus pseudocalceolaris is also close to G. acaulis (Lindley 1833: 227) Kuntze (1891: 661), but the shape of sepals and petals are different (broadly obovate to spathulate and much incurved) in G. acaulis and it has a projection inside the hypochile (FIGURE 3C) which is absent in the new species.Published as part of Dey, Santanu, Phom, Limamanen, Bhattacharjee, Avishek & Eshuo, Kazhuhrii, 2022, Gastrochilus pseudocalceolaris, a new species of epiphytic orchid from India, pp. 295-300 in Phytotaxa 574 (4) on pages 295-299, DOI: 10.11646/phytotaxa.574.4.5, http://zenodo.org/record/738910
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