179,872 research outputs found
Mediorhynchus amini R. & Smales 2014, sp. n.
No full textMediorhynchus amini sp. n. Figs 9-17 MATERIAL EXAMINED: MHNG-INVE-84833; holotype male, small intestine, Myiarchus ferox (Gmelin, 1789) (Tyrannidae), Paraguay, Route Filadelfia-Teniente, Montana 8 km, 23.11.1993. – MHNG-INVE-84844; paratype (allotype) female, small intestine, Myiarchus ferox (Gmelin, 1789), Paraguay, Filadelfia-Teniente, Montana 8 km, 23.11.1993. – MHNG-INVE- 38411; 1 male, 2 females, 7 pieces of female, paratypes, small intestine, Myiarchus ferox (Gmelin, 1789), Paraguay, Filadelfia-Teniente, Montana 8 km, 23.11.1993. – MHNG-INVE- 38434; 1 female voucher specimen, small intestine, Myiarchus ferox (Gmelin, 1789), Carapegua, 10.10.1982. ETYMOLOGY: The species is named to recognize the contribution of Dr Omar Amin to acanthocephalan taxonomy. DESCRIPTION General: (based on 2 males, 4 females) Robust worms, medium sized, trunk cylindrical, thick, with shoulders, posterior third expanded in male, slightly tapering at posterior end in female, aspinose (Figs 9, 11). Main lacunar canals with regular lateral branches. Proboscis conical, truncated, in 2 parts; anterior proboscis with rooted hooks, posterior proboscis wider, with spines; hooks and spines embedded in cuticular papillae when proboscis not fully extended. Roots of hooks flask shaped with rounded larger posterior ends, spines slender with either reduced slender flask shaped roots or basal discs. Proboscis armature similar in both sexes, 22-24 rows of 5-6 hooks, about same number of irregular rows 5-6 spines (Fig. 10). Hook lengths, sequence of 2 longitudinal rows measured from anterior, 7 -; 18, 18; 16.5, 16; 22, 12; 13, 12; 13, 8 long; spines 5, 10 long (Figs 13, 14). Neck unarmed, conical, widest at junction with broader trunk. Proboscis receptacle attached anteriorly at junction between anterior and posterior proboscis, about twice as long as proboscis, with cerebral ganglion near mid region (Fig 16). Lemnisci long, slender, equal, inserted at base of neck (Fig. 9). Genital pore, male and female, terminal. Male: (Based on 2 specimens) Trunk 9.1, 11 mm long, 680, 850 wide. Proboscis 470 long, 370 wide; anterior proboscis 290, posterior proboscis 180. Neck 120 long, 300 wide. Proboscis receptacle 850 long, 320 at widest part. Lemnisci 2800 long, 100 wide. Testes ovoid, tandem, contiguous, in posterior third of trunk; anterior testis 680 long, 305 wide; posterior testis 985 long, 440 wide. Cement glands 8 globular, in cluster, each about 100 wide. Saefftigen’s pouch 600 long (Fig. 15). Female: (based on 4 specimens) Trunk 15-22 (18.75) mm long, 670-1105 (826) wide. Proboscis 415-770 (630) long; anterior proboscis 230-380 (350) long, posterior proboscis 185-385 (373) long; 315-375 (337) wide. Neck 105-170 (150) long, 370-450 (423) wide. Proboscis receptacle 670-750 (707) long, 215-220 (217) wide. Lemnisci 7500 (1 measurement) long, 110 wide. Reproductive tract, 500, 600 long (Fig. 17). Eggs ovoid, with concentric shells and thin outer membrane; 49.5-56.1 (52.8) long, 26.4-29.7 (28.0) wide (Fig. 12). COMMENTS: Mediorhynchus amini sp. n. demonstrates the characters of the genus as described by Van Cleave (1916) and discussed by Schmidt & Kuntz (1977) and Amin & Dailey (1998). None of the species of Mediorhynchus described to date have spines with markedly reduced, but typically shaped, roots on the posterior proboscis. Consideration of the key of Schmidt & Kuntz (1977) indicated that M. amini with a proboscis armature of 22-24 rows of 5-6 hooks, largest hooks 18-22 was most similar to M. corcoracis Johnston & Edmonds, 1951 with 22 rows of 5-6 hooks, largest hooks 14-18. Mediorhynchus amini further differs from M. corcoracis in having about the same number of rows of 5-6 spines compared with 40 rows of 4-5 spines. Mediorhynchus amini, is a much smaller worm (males 9-11, compared with 25-33 mm long) with smaller testes (680-985 compared with 1600-2600) than M. corcoracis (Johnston & Edmonds, 1951). Of the species listed or described by Amin et al. (2008) since the key was developed; namely M. channapettae George & Nadakal, 1984, M. fatimaae, Khan, Bilqees & Muti-ur-Rehman, 2004, M. lophurae Wang, 1966, M. mariae George & Nadakal, 1984, M. mattei, Marchand & Vassiliades, 1982, M. nickoli Khan, Bilqees & Muti-ur-Rehman, 2004, M. rajasthanensis Gupta, 1976 and M. lanius Amin, Ha & Heckman, 2008 only M. lanius with 22 rows of 6-7 hooks and 29 rows of 4-5 spines has a proboscis hook formula approaching that of M. amini. Mediorhynchus amini, however, further differs from M. lanius in being a smaller worm (males 9-11 compared with 28. 75 mm long) and having smaller hooks and spines (hooks 7-18, spines 5-10 long, compared with hooks 35-45, spines 30-37 long) (Gupta, 1976; Marchand & Vassiliades, 1982; George & Nadakal, 1984; Khan et al., 2004; Amin et al., 2008). An additional 7 species are known including; M. colluricinclae Smales, 2002, (proboscis armature 26-28 rows of 7-8 hooks and 36-38 rows of 3-8 spines), M. cisticolae Smales, 2011 (proboscis armature 20-22 rows of 5-6 hooks and 26 rows of 2-3 spines), M. gibsoni Bilqees, Khan, Khatoon & Khatoon, 2007 (proboscis armature 25 rows of 8-12 hooks and 10 rows of 8-16 spines), M. spinaepaucitas Smales, 2011 (proboscis armature 20-22 rows of 4-5 hooks and 30 rows of 4-5 spines), and M. turdi Smales, 2011 (proboscis armature 24-28 rows of 7-9 hooks and 35-40 rows of 3-5 spines) (Bilqees et al., 2007; Smales, 2011). None of the above species have proboscis armature similar to that of M. amini. Mediorhynchus peruensis (proboscis armature 14-16 rows of 4-6 hooks and a total of 104-120 spines) (Moya et al., 2011) is the only species to have been described from South America since Amin et al. (2008) reviewed the genus. The proboscis armature of M. amini (22-24 rows of 5-6 hooks and 5-6 spines), however, does not resemble that of M. peruensis (Moya et al., 2011).Published as part of Smales, L. R., 2014, Acanthocephala, including the descriptions of two new species of Mediorhynchus (Gigantorhynchidae) from birds from Paraguay, South America, pp. 261-276 in Revue suisse de Zoologie 121 (2) on pages 269-272, DOI: 10.5281/zenodo.582304
Equivalence of Diagonal Matrices over Local Rings
No full textIt is proved that two diagonal matrices diag(a_1,...,a_n) and diag(b_1,...,b_n) over a local ring R are equivalent if and only if there are two permutations σ,τ of {1,2,...,n} such that l[R/aiR]=l[R/bσ(i)R] and e[R/aiR]=e[R/bτ(i)R] for every i=1,2,...,n. Here e[R/aR] denotes the epigeny class of R/aR, and l[R/aR] denotes the lower part of R/aR. In some particular cases, like for instance in the case of R local commutative, diag(a_1,...,a_n) is equivalent to diag(b_1,...,b_n) if and only if there is a permutation σ of {1,2,...,n} with a_iR=b_{σ(i)}R for every i=1,...,n. These results are obtained studying the direct-sum decompositions of finite direct sums of cyclically presented modules over local rings. The theory of these decompositions turns out to be incredibly similar to the theory of direct-sum decompositions of finite direct sums of uniserial modules over arbitrary rings
Direct summands of direct sums of modules whose endomorphism rings have two maximal right ideals
No full textAbstractLet M1,…,Mn be right modules over a ring R. Suppose that the endomorphism ring EndR(Mi) of each module Mi has at most two maximal right ideals. Is it true that every direct summand of M1⊕⋯⊕Mn is a direct sum of modules whose endomorphism rings also have at most two maximal right ideals? We show that the answer is negative in general, but affirmative under further hypotheses. The endomorphism ring of uniserial modules, that is, the modules whose lattice of submodules is linearly ordered under inclusion, always has at most two maximal right ideals, and Pavel Příhoda showed in 2004 that the answer to our question is affirmative for direct sums of finitely many uniserial modules
Zooplankton abundance in Amini and Kadmat islands of Lakshadweep
No full textStudies on zooplankters collected from the lagoons of Amini and Kadmat islands of Lakshadweep Archipelago were carried out based on a survey conducted during January - February, 2014. The displacement volume ofzooplankton in Amini and Kadmat were 58.35 and 15ml per 100 m3 respectively. The density was also higher in Amini than in Kadmat which is estimated as 64480 and 47726 numbers per 100 m3 respectively. A total of twentyone groups of zooplankters viz., copepods,ostracods, chaetognaths, Lucifer sp., medusae, doliolids,mysids, tintinnids, euphausiids, appendicularians,siphonophores, cladocera, amphipods, isopods,polychaete larvae, prawn larvae, crab larvae, squilla larvae, molluscan larvae, fish eggs and fish larvae were recorded from these two ecosystems. Groupwise studies indicated the dominance of copepods in Amini forming 40% while in Kadmat, the maximum was contributed by crab larvae (50%). The dominance of crab larvae in Kadmat was due to a swarm of zoea stage of crab at station 2 in the western side of the island.Among the copepods, calanoid copepods contributed the maximum with 71% in Amini and 81% in Kadmat.Followed by the dominance of copepods in Amini,ostracods (33%) and crab larvae (14%) formed major components. In Kadmat, copepods formed the second dominant group which contributed 20% followed by prawn larvae (11%), ostracods (6%) and the share by other groups were less than 5%. Comparative studies on the occurrence of different groups of zooplankters in these two island ecosystems showed that copepods and ostracods were very much higher in Amini than in Kadmat while, crab larvae contributed more in Kadmat which was due to the swarming of zoea stage of crab. Both qualitative and quantitative abundance of zooplankters in these two ecosystems are presentedand discussed
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Analytical modeling of ultrasonic surface burnishing process: Evaluation of residual stress field distribution and strip deflection
No full textUltrasonic surface burnishing (USB) process is a promising surface enhancement technique that improves fatigue life of components by exerting work hardening and compressive residual stress of the surface layers. However, USB is a complex process in practice, and there is not an analytical model published to facilitate the design and comprehension of the process. In the present paper an analytical elastic-plastic model was developed to correlate USB process factors to residual stress field (RSF). Also, deformation of strip samples was determined in the analytical approach. Parameters such static force, ultrasonic vibration amplitude, ball material and its diameter as well as ultrasonic vibration frequency were included in the model to find how they influence the residual stress variation and strip deflection. Two types of material constitutive equation i.e. Johnson-Cook (JC) that is sensitive to strain rate as well as Chaboche hardening that is influenced by cyclic loading were considered to find which material behavior is more consistent with experimental results. The experiments have been carried out on two different materials with various initial state of residual stress field (IRSF). It was obtained from the results that residual stress field variation and strip deflection obtained by experiments are consistent well with the values derived from analytical model. Therefore, the model was comprehensively used to find how the USB process factors influence the RSF and strip deflection
Numerical investigation of indoor thermal comfort and air quality for a multi-purpose hall with various shading and glazing ratios
No full textThis research assesses the effect of outdoor parameters, including solar radiation and shading and glazing configurations, on indoor thermal comfort and air quality in multi-purpose halls in Auckland, New Zealand. The Design of Experiment (DOE) method by using CFD simulation has been utilized for this study. Input parameters are windows length, overhang angle, and overhang length, while output parameters are occupant zone average temperature and mass fraction. The temperature sensitivity to the glazing parameter changes with time, and its maximum occurs at 11:00 and is 95%, while for the shading ones happen at 9:00 and is 50%. The peak of CO2 mass fraction sensitivity to glazing and shading parameters coincides at 9:00 and is 90% and 80, respectively. The variation rate of temperature and CO2 mass fraction VS. Glazing parameter (W.L) is approximately positive on the summer day. However, it has a nonlinear and complex behavior, while the shading one has a sinusoidal behavior. On the other hand, on the winter day, the temperature variation rate is almost linear regarding this factor. The result shows that appropriate shading and glazing situation for each time is different, and for reaching the best comfort, dynamic shading and glazing should be designed. Comfort criteria sensitivity within the school is highly dependent on glazing parameters compared with shading configurations. The temperature can be controlled up to 3 and 1.6 degrees on the summer and winter day, respectively. Finally, it can be concluded that glazing tools can compensate for a significant amount of required heating in the winter days, and shading devices and openings can control the air quality in the school buildings with neglectable overheating
Unraveling the resource puzzle: exploring entrepreneurial resource management and the quest for new venture success
No full textExisting research highlights resource management as a complicated and multifaceted system comprising interdependent components, rather than a collection of independent factors. Nonetheless, the precise influence of resource management approaches on value generation and overall prosperity in new business endeavors, especially within diverse contextual environments, remains unclear. To address this gap, our study adopts a neo-configurational approach to explore how entrepreneurial resource management components (e.g., structuring, bundling, and leveraging) relate to achieving success in start-ups. We also examine the contextual influence of environmental dynamism and munificence on the effectiveness of these resource management strategies. By analyzing a comprehensive sample of over 500 US-based ventures, we develop a theoretical framework that encompasses four distinct resource management strategies. This framework provides insights into the attainment of success across diverse environments, characterized by varying levels of dynamism and munificence. Our study contributes to extant literature by emphasizing that the achievement of a competitive advantage in entrepreneurial firms is contingent upon the alignment of internal resource management strategies with external factors, specifically dynamism and munificence
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Bayesian Model Averaging in R
No full textBayesian model averaging has increasingly witnessed applications across an array of empirical contexts. However, the dearth of available statistical software which allows one to engage in a model averaging exercise is limited. It is common for consumers of these methods to develop their own code, which has obvious appeal. However, canned statistical software can ameliorate one's own analysis if they are not intimately familiar with the nuances of computer coding. Moreover, many researchers would prefer user ready software to mitigate the inevitable time costs that arise when hard coding an econometric estimator. To that end, this paper describes the relative merits and attractiveness of several competing packages in the statistical environment R to implement a Bayesian model averaging exercise.Model Averaging, Zellner's g Prior, BMS
- …
