5,766 research outputs found
Vascular functioning and development of the kiwifruit berry (Actinidia deliciosa)
No full textThe aim of this study was to understand kiwifruit berry development and the role of cell turgor and the phloem unloading pathway in development. Important aspects of berry development include the size of the fruit and its composition. The fresh weight growth curve of the kiwifruit berry was shown to be double sigmoid in shape. Dry weight accumulated linearly for the initial 139 days after anthesis (DAA). At this time the soluble solids concentration began to increase. Berry firmness was measured using two methods, with the penetrometer and with a new non-destructive method, utilising skinfold callipers. Both methods exhibited similar results, indicating that the skin callipers may be useful in the future for non-destructive berry rheological measurements.
Cell turgor was measured indirectly from measurements of symplasmic and apoplasmic solute potentials, and the matric potential of the berry. Apoplasmic sap, required to measure the apoplasmic solute potential, was extracted using two different methods the pressure chamber and through centrifugation. Measurements of sap osmotic potential suggest that the sap extracted using the centrifuge was contaminated with symplasmic sap, resulting in a negative cell turgor estimate. However, the pressure chamber technique provided apoplasmic sap that produced a more accurate estimate of cell turgor. Direct estimates of cell turgor were only obtained from the midpoint of the growing season because of contamination with symplasmic sap, but the values obtained were comparable to literature values for developing grape and tomato berries.
The phloem unloading pathway in the fruit was investigated using a symplasmic tracer dye, carboxyfluorescein diacetate coupled with 14C labelling and autoradiography. The phloem unloading pathway was symplasmic until 91 DAA when the dye was restricted to the phloem cells only, indicating a change to an apoplasmic pathway. However, due to the lack of functional unloading seen in radiolabelled samples, a change in the phloem unloading pathway could not be confirmed
Fake Airy functions and the asymptotics of reflectionlessness
No full textTwo classes of analytic refractive-index profile P2(z,ε ), whose reflection coefficients r are zero for all values of a parameter in , are studied as in to 0. The aim is to understand why r=0 rather than r varies as exp(-1/ε ) as for generic profiles. The authors find that reflectionlessness is a consequence of the fact that transition points of P2 (zeros or poles in the complex z plane) form tight clusters (whose size vanishes with in ) which can be regarded neither as coalesced nor well separated. Expansion near a cluster yields the local wave not as the usual Airy function, whose Stokes phenomenon generates reflection, but as Bessel functions of half-integer order (fake Airy functions) which are exactly trigonometric functions with no Stokes phenomenon and so no reflection
Unfolding the high orders of asymptotic expansions with coalescing saddles: singularity theory, crossover and duality
No full textWe study the leading behaviour of the late coefficients (high orders r) of asymptotic expansions in a large parameter k, for contour integrals involving a cluster of coalescing saddles, and thereby establish the form of the divergence of the expansions. The two principal cases are: 'saddle-to-cluster’, where the integral is through a simple saddle and its expansion diverges because of a distant cluster; and 'cluster-to-saddle', where the integral is through a cluster and its expansion diverges because of a distant simple saddle. In both, the large-r coefficients are dominated by the 'factorial divided by power' familiar in asymptotics, but this changes its form as the saddles in the cluster are made to coalesce and separate by varying parameters A= {A1,A2....} in the integrand. The 'crossover' between different forms is described by a series of canonical integrals, built from the cuspoid catastrophe polynomials of singularity theory that describe the geometry of the coalescence. The arguments of these integrals involve not only the A but also fractional powers of r, which by a curious duality replace the powers of the original large parameter k which occur in uniform approximations involving these integrals. A by-product of the cluster-to-saddle analysis is a new exact formula for the coefficients of uniform asymptotic expansions
Sex Addiction: the Chicken-and-Egg Dilemma of Diagnosis
No full textIn May 2013, the American Psychiatric Association will release the next version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). Interestingly, sex addiction, despite significant attention from mainstream media, will be omitted from the manual. This omission presents a challenge to clinicians who treat sex addiction, and researchers aiming to further our understanding of the issue. This commentary outlines some of the reasons sex addiction was not included in the DSM-V, including a ‘chicken-and-egg’ conundrum, which makes it difficult to generate research without a clear diagnosis, and difficult to establish a definitive diagnosis without a supportive body of research
Labahitha nicobarensis Magalhaes & Berry & Koh & Gray 2022, comb. nov.
No full textLabahitha nicobarensis (Tikader, 1977) comb. nov. Filistata nicobarensis Tikader, 1977: 160, fig. 1A–C. Holotype female and paratype male and females from India, Car Nicobar, 8 Mar. 1970, B.K. Tikader leg., deposited in the National Collection, Zoological Survey of India, Calcutta or in the Zoological Survey of India, Poona, not examined. Pritha nicobarensis – Patel 1978: 186. Notes We have not examined the type specimens, but the teardrop-shaped bulb with a keel-like paraembolic lamina figured in the original description (Tikader 1977: fig. 1C) clearly indicates this species belongs to Labahitha. We provided a tentative diagnosis and consider this species as valid, but re-examination of the type material would be desirable to confirm its validity. It should be noted that there is an older available name based on specimens also from the Nicobar islands, Filistata insularis Thorell, 1891, which we were unable to examine; it is not unlikely that they could be synonyms. Diagnosis Males are similar to those of L. oonopiformis, L. ryukyuensis and L. garciai by the teardrop-shaped bulb with a keel-shaped paraembolic lamina. They differ from all these species by the shorter, more straight and robust embolus (Tikader 1977: fig. 1c). The female genitalia has never been illustrated and thus we are unable to provide a diagnosis for the female at this time. Description See Tikader (1977). Distribution India, Andaman and Nicobar islands (Fig. 1B).Published as part of Magalhaes, Ivan L. F., Berry, James W., Koh, Joseph K. H. & Gray, Michael R., 2022, Labahitha spiders (Arachnida: Araneae: Filistatidae) from islands in the Indian and Pacific Oceans, pp. 1-51 in European Journal of Taxonomy 805 (1) on page 36, DOI: 10.5852/ejt.2022.805.1693, http://zenodo.org/record/637382
Labahitha ryukyuensis Magalhaes & Berry & Koh & Gray 2022, comb. nov.
No full textLabahitha ryukyuensis (Ono, 2013) comb. nov. Tricalamus ryukyuensis Ono, 2013: 16, figs 1–11. Holotype male (NSMT-Ar 9930) and paratype males and females (NSMT-Ar 9931–9935) from Kamara, Okinawa-shi, Okinawa Prefecture (Okinawajima Island), Japan, 22 May 2011, T. Naka leg., deposited in the National Museum of Nature and Science, Tokyo, not examined. Notes The structure of the male palp (drop-shaped bulb with a keel-shaped paraembolic lamina; Ono 2013: figs 1–3) and somatic morphology indicate this species belongs in Labahitha and is a close relative of L. oonopiformis, L. garciai and L. nicobarensis, thus we propose the new combination. Diagnosis Males are similar to those of L. oonopiformis, L. garciai and L. nicobarensis by the teardrop-shaped bulb with a keel-shaped paraembolic lamina. They differ by the more slender palpal tibia, the less globose base of the bulb (Ono 2013: figs 1–3) (vs palpal tibia shorter and stouter, bulb base globose). Females are more similar to those of L. oonopiformis, L. garciai and L. gibsonhilli by the large membranous base of the receptacles and well-developed median receptacle; they differ in having the median receptacles smaller than the laterals (Ono 2013: fig. 9) (vs median receptacles subequal in size or larger than the laterals). Description See Ono (2013). Natural history Ono (2013) reports that specimens were collected in delicate webs with a central tubular retreat in inclined ground in the edge of a forest. One egg-sac had approximately 40 eggs. Distribution Known only from the type locality (Okinawajima Island, Japan) (Ono 2013) (Fig. 1).Published as part of Magalhaes, Ivan L. F., Berry, James W., Koh, Joseph K. H. & Gray, Michael R., 2022, Labahitha spiders (Arachnida: Araneae: Filistatidae) from islands in the Indian and Pacific Oceans, pp. 1-51 in European Journal of Taxonomy 805 (1) on pages 41-43, DOI: 10.5852/ejt.2022.805.1693, http://zenodo.org/record/637382
Technical and marketing support systems for successful small and medium-size enterprises in four countries
Get PDFStudies of successful and medium-size enterprises (SMEs) and their marketing and technical support systems were undertaken for Colombia, Indonesia, Japan, and the Republic of Korea. Three to four subsectors were examined in each country. The sample worldwide amounted to 445 firms. Mechanisms to support export marketing varied across countries and subsectors. How they varied depended greatly on whether SMEs operated within well-developed private networks. When market penetration begins, transaction costs are high and collective marketing support can be important. As markets"thicken,"initiatives by foreign buyers become more important. Generally the most effective collective marketing support was of the kind that can be provided more effectively by decentralized organizations - such as industry associations or local governments and chambers of commerce (support firms'participation in trade fairs, for example) - than by central government institutions. Private mechanisms were more important than collective mechanisms for helping firms improve their technological capability. Demand for collective mechanisms tended to be greater when technological requirements of production were complex or when the endowments of private technological networks in certain countries or industries were weak. Broad-based collective technical support facilitates the emergence of an information-rich environment for firms, and may be worth pursuing in many settings. Examples of such support include: 1) sponsoring courses in specialized topics; 2) facilitating the use of expert consultants (either directly, by making a consultant available to a broad array of firms, or indirectly, by providing financial support for the use of consultants); and 3) promoting information-sharing among firms. Countries that already have strong broad-based collective support and that are moving into technologically more advanced activities might consider"high-intensity"support, but should proceed with caution.Microfinance,Small and Medium Size Enterprises,Small Scale Enterprise,Markets and Market Access,Water Conservation,Microfinance,Private Participation in Infrastructure,Small Scale Enterprise,Access to Markets,Markets and Market Access
Labahitha fuscata Magalhaes & Berry & Koh & Gray 2022, comb. nov.
No full textLabahitha fuscata (Nakatsudi, 1943) comb. nov. Figs 2A–B, 4–6, 29C Filistata fuscata Nakatsudi, 1943: 148, fig. 1a–c. Female holotype from Palau, Koror Island, Aug.1941, T. Ogata leg., presumably deposited in the Tokyo University of Agriculture (Ono 2011), not examined. Filistata fuscata Kishida, 1947: 999, fig. 2839. Syntypes from Japanese Micronesia, currently untraceable (Ono 2011), not examined. First considered a junior synonym and homonym of Filistata fuscata Nakatsudi, 1943 by Ono (2011). Nr. Wandella sp. – Gray 1995: 84, figs 15, 19. Tricalamus fuscatus – Ono 2011: 185, figs 1–11; 2013: 19. Notes Although neither Ono (2011) nor we have examined the type specimens, we have seen plenty of specimens from the type locality and neighbouring islands that tally with the original descriptions of this species. Ono (2013) recorded this species in the Ogasawara Islands in Japan. Gray (1995: fig. 15) was the first to figure the male of this species. See Ono (2011) for a discussion regarding the correct authorship of this species and the priority of Nakatsudi’s (1943) name over Kishida’s (1947). Diagnosis The male is similar to that of Labahitha gibsonhilli in the sharp, triangular apex of the paraembolic lamina and the gently curved distal portion of the sperm duct. It differs by the shorter, more stout palpal bulb and the relatively larger paraembolic lamina (Fig. 5B, J–L) (vs palpal bulb longer and slender, with smaller paraembolic lamina in L. gibsonhilli). Females can be distinguished from all congeners by the very small median receptacles, which are reduced to a bump with pores, placed posteriorly to the larger, oval lateral receptacles (Fig. 6). The deep brown and uniform colouration is also characteristic (Fig. 4), although also present in L. ryukyuensis (Ono 2013). Material examined AUSTRALIA • 1 ♂; Queensland, Torres Strait, Darnley Island; [9.59747° S, 143.76142° E]; AM. BRUNEI • 1 ♀; Tutong, Tasek Merimbun Park HQ; [4.59444° N, 114.67083° E]; 13 Feb. 2013; J.K.H. Koh leg.; wooden wall crevices; JK 130213.1101 • 1 ♀; same collection data as for preceding; 16 Apr. 2011; JK 110416.1907. FIJI • 1 ♀; Vanua Levu, Lasema; [16.62682° S, 179.01793° E]; W.M. Mann leg.; MCZ 40200. MARSHALL ISLANDS • 1 ♀; Kwajalein Atoll, Ennugarret Island; [9.38452° N, 167.4881° E]; 9 Jul. 1968; J.W. Berry leg.; beating trees in Pandanus forest; JBJB • 1 ♂; Majuro Atoll, Woja; [7.09171° N, 171.38268° E]; 26 Jul. 1968; J.W. Berry leg.; in coconut litter; JBJB. MICRONESIA • 1 ♀; Caroline Islands, “ Truk Islands ” [Chuuk Island], “ Moen Island ” [Weno Island]; [7.45575° N, 151.84985° E]; 12 Jun. 1978; J. Berry and Beatty leg.; in crevices on buildings; JBJB • 1 ♀; Caroline Islands, Yap Island, Yap District, Fedor; [9.45056° N, 138.06269° E]; 1 Feb. 1980; J.W. Berry leg.; in banana leaves; JBJB • 1 ♀; Caroline Islands, Yap Island, Yap District, Fedor; [9.45056° N, 138.06269° E]; 13 Apr. 1980; J.A. Beatty leg.; in web on tree trunk; JBJB • 1 ♂, 1 ♀; Caroline Islands, Yap Island, Yap, near Gilman Point; [9.45056° N, 138.06269° E]; 15 Apr. 1980; webs in crevices on mango tree bark; JBJB. NEW CALEDONIA • 2 ♀♀, 1 imm.; Nord, Poum; [20.23333° S, 164.01667° E]; 13 Feb. 1993; N.I. Platnick, R.J. Raven and M.S. Harvey leg.; coastal cliffs; AMNH IFM-0917, IFM-0918. PALAU • 1 ♂; Caroline Islands, Koror Island; [7.34068° N, 134.4792° E]; 17 Mar. 1973; J. Berry and Beatty leg.; in cave entrance rock cracks; JBJB • 1 ♀; same collection data as for preceding; JBJB • 1 ♀; Caroline Islands, Koror Island; [7.34068° N, 134.4792° E]; 17 Mar. 1973; J. Berry and J. Beatty leg.; in crevices of tree trunk bark; JBJB • 1 ♂, 1 ♀; Caroline Islands, Koror Island, on Entomology Lab building; [7.34068° N, 134.4792° E]; 7 Mar. 1973; J.A. Beatty leg.; JBJB • 1 ♀; same collection data as for preceding; 6 Mar. 1973; J. Berry and J. Beatty leg.; JBJB. PAPUA NEW GUINEA • 2 ♀♀; Bismarck Islands; [5.55234° S, 150.13883° E]; 18 Nov. 1896; ZMB. Description Male (from Palau, Koror Island, Entomology Laboratory, JBJB) COLOURATION (in ethanol). Carapace grey-brown, with darker irregular patterning in the median postocular area and the weakly defined mid-lateral and lateral marginal bands. Chelicerae, labium, endites and sternum brown. Legs with dark grey-brown pigmentation on femora, paler on tibiae and reduced to absent on remaining segments. Abdomen colour brownish grey with and several indistinct chevrons, but patterning poorly preserved. HABITUS. Anterior margin of carapace subrounded, sclerotized but apical part with an unsclerotized curved edge. Sternum subrounded, posteriorly bluntly pointed, a pair of posterior sigilla present. MEASUREMENTS. Total length 3.23. Carapace length 1.37, width 1.13. Clypeus length 0.33. Eye diameters and interdistances: AME 0.05, PME 0.08, ALE 0.09, PLE 0.09, AME–AME 0.05, PME–PME 0.09. Sternum length 0.95, width 0.71. Palp: femur length 0.77, height 0.23; tibia length 0.49, height 0.22. Legs 1423. Leg I: 6.33 (1.63, 0.49, 1.80, 1.42, 0.99). II: 4.63 (1.24, 0.43, 1.14, 1.18, 0.64). III: 4.26 (1.10, 0.39, 0.95, 1.07, 0.75). IV: 5.41 (1.41, 0.49, 1.43, 1.44, 0.64). Abdomen length 1.86, width 0.86. LEG MACROSETAE. Metatarsus (Mt) I 1 a.vr. PALP (Fig. 5). Cymbium horseshoe shaped; bulb enlarged with a median constriction, sperm duct Nshaped with a single coil; tegulum with a large prolateral excavation, its surface adorned with strongly spined short ridges (each typically bispinate); large crest-like paraembolic process with a fimbriated dorsal margin bent more or less prolaterally, and narrowing distally to end in an extension above the embolus; comb-like microtooth arrays present on paraembolic process; embolus slender, slightly curved. Female (from Palau, Koror Island, Entomology Laboratory, JBJB) COLOURATION. Carapace similar to male, but anterior margin of carapace pigmented. Abdomen greyish brown with a longitudinal pale patch mid-dorsally and several indistinct pale chevrons laterally. One pair of posterior sternal sigilla present. MEASUREMENTS. Total length 4.75. Carapace length 1.69, width 1.33. Clypeus length 0.29. Sternum length 0.95, width 0.71. Palp: femur length 0.91, height 0.3; tibia length 0.42, height 0.3. Leg I: 5.71 (1.45, 0.52, 1.49, 1.32, 0.93). II: 4.22 (1.16, 0.49, 0.95, 0.95, 0.67). III: 3.7 (1.05, 0.48, 0.78, 0.85, 0.54). IV: 4.92 (1.41, 0.60, 1.25, 1.05, 0.61). Abdomen length 3.06, width 2.07. LEG MACROSETAE. Absent. Calamistrum with three rows. EPIGASTRIC FURROW. Unmodified. ENDOGYNE (Fig. 6). Median lobes very small with a few clustered pores; lateral lobes large, ovoid in side view, with scattered pores. Variation Male genitalia is similar across islands (Fig. 5). The shape of the lateral receptacles varies from rounded to oval, and the pores in the lateral receptacles may be concentrated in the ectal side or dispersed throughout the receptacle (Fig. 6). Natural history Specimens have been collected in habitats as diverse as wooden wall crevices, in coconut litter, in crevices on buildings, by beating trees in Pandanus forest, in banana leaves, in web on tree trunk, in webs in crevices on tree bark, in coastal cliffs and in cave entrance rock cracks. Distribution Widespread in Micronesia and Melanesia, extending into Borneo and Japan (Fig. 1).Published as part of Magalhaes, Ivan L. F., Berry, James W., Koh, Joseph K. H. & Gray, Michael R., 2022, Labahitha spiders (Arachnida: Araneae: Filistatidae) from islands in the Indian and Pacific Oceans, pp. 1-51 in European Journal of Taxonomy 805 (1) on pages 6-12, DOI: 10.5852/ejt.2022.805.1693, http://zenodo.org/record/637382
Enhancing the Polymeric Landscape for 3D Printing Using Post-Fabrication and Supramolecular Design
No full textAdditive manufacturing, also known as 3D printing, is a process of materials fabrication assisted
by computer aided design (CAD) to form three-dimensional objects with complex geometry. Many
3D printing techniques have been developed since the inception of the process, with three of the
most popular and affordable being Fused Deposition Modeling (FDM), Stereolithography (SLA)
and Direct-Ink Writing (DIW). While 3D printing has many advantages, it is plagued with
limitations such as poor interlayer adhesion, limited resolution, rough surface finish, limited
mechanical properties of printed parts, and limited compatible materials. For these reasons, 3D
printing has been mainly limited to prototyping and has not been adapted for mass production
manufacturing. To address the limitations associated with 3D printed objects, we have developed
several techniques and formulations to improve the performance and broaden the applications of
3D printed materials. To address the poor resolution associated with FDM printing, we have
employed a base hydrolysis reaction of the common 3D printing filament polylactic acid. We
demonstrated how printed microneedle arrays could be “chemically etched” with a potassium
hydroxide solution to the appropriate dimensions for applications as transdermal drug delivery
devices. To address mechanical strength, we introduced a cost effective, biopolymer-based
hydrogel for applications in water purification fabricated via DIW. It was demonstrated that the
addition of chitosan to a commercially available shear-thinning polymer resulted in an increase in
Young’s modulus as well as functionality capable of chelating toxic heavy metals, which was
enhanced by increased surface area only achievable through 3D printing. We have also shown how
post-fabrication of hydrogels can be achieved through base catalyzed thiol-Michael click
chemistry, which in contrast to traditional radical crosslinking methods, allowed for tuning the of
mechanical properties through the use of various crosslinkers and also enhanced degradation, a
feature of the thiol/acrylate Michael addition adduct. Lastly, we aimed to address limitations in
available materials by developing a facile method of synthesizing slide-ring gel materials through
a catalyst-free thiol-Michael addition, which resulted in a stretchable gel material. We hope to
further characterize and adapt this method to be compatible with the EMB3D 3D printing process.
Chapter 1 provides and introduction to available 3D printing techniques, previous methods of
addressing limitations associated with 3D printing, and a background on new materials and
potential materials for 3D printing.
Chapter 2 describes our advances in 3D printing through the development of chemical etching
methods for the fabrication of biodegradable 3D printed microneedles for transdermal drug
delivery, and the formulation and fabrication of a biopolymer-based hydrogel for toxic heavy metal
absorption from water.
Chapter 3 describes chemical methods for 3D printing through a radical free post-fabrication
method of crosslinking hydrogels in solution through a based catalyzed thiol-Michael addition.
Chapter 4 describes potential new materials for 3D printing through the fabrication of slide-ring
gel materials using a “one-pot” synthetic approach, with the end goal of adapting the system for
EMB3D 3D printing
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