14,040 research outputs found
TWO NEW SPECIES OF POACEAE FROM INDIA
No full textTwo new species of Poaceae namely, Erayrostis santapaui K. G. Bhat & C. R. Nagendran and Chrysopogon pseitdozeylanicus K. G. Bhat & C. R. Nagendran have been described from materials collected by the senior author from Coorg- and South Kanara Districts of Karnataka State, India
Food for nought
No full textThe short story, "Food for nought", is written by the listed author above, Shashi Bhat. Now in its 48th year, Best Canadian Stories has long championed the short story form and highlighted the work of many of the writers, throughout their respective careers, who have gone on to shape the Canadian literary canon. Caroline Adderson, Margaret Atwood, Clark Blaise, Lynn Coady, Mavis Gallant, Zsuzsi Gartner, Douglas Glover, Steven Heighton, Isabel Huggan, Mark Anthony Jarman, Norman Levine, Rohinton Mistry, Alice Munro, Leon Rooke, Diane Schoemperlen, Russell Smith, Linda Svendsen, Kathleen Winter, and many others have appeared in its pages over the years and decades, making Best Canadian Stories the go-to source for what’s new in Canadian fiction writing for close to five decades. A continuation of not only a series, but a legacy in Canadian letters. --From publisher description.Published
Modelling individual preferences, State of the art, recent advances and future directions.
No full textDespite the above famous statement, individuals have always disputed about individual tastes, and the decision making processes behind consumers’ choices has been a focal interest for decades. Although challenges against the theory of rational behaviour date back to the work of von Neumann and Morgenstern (1944), the dominating approach (at least in the transport field) has been the neoclassical economics assumption of rational decision makers (or even more extreme homo economicus), who always perform well planned and consistent activities, aiming to maximize some subjective measure of value (McFadden, 1999). The reason for this dominance is that economic theory has provided an elegant, rigorous and at the same time relatively easy to implement model, designed to describe individuals’ decisions and to provide quantitative forecasts with well-defined statistical properties. On the other hand, although investigations in psychology have made an impression on economic thought1 , they have tended to generate lists of errors and biases and have mostly failed (with excellent exceptions) to offer a coherent alternative to the rational-agent model (Kahneman, 2003). Psychologists recognise that this complaint is justified, at least partly, because intuitive thought cannot match the elegance and power of formal normative models. However, as Kahneman (2003) points out … “the alternative to simple and precise models is not chaos; psychology offers integrative concepts and mid-level generalizations, which gain credibility from their ability to explain ostensibly different phenomena in diverse domains”. The origin of this divergence relies on the historically different views of the decision-making process between neoclassical economics and psychology. While economists have been interested in mapping from information inputs to choice, treating the decision process as a black box, psychologists’ prime objective has been to understand what happens inside that black box: the nature of these decision elements, how they are established and modified by experience, and how they determine values. McFadden (1999) notes that what has made the distance between the two approaches even bigger is that psychologists view the decision process as dynamic and individual behaviour as local, adaptive, learned, dependent on context, mutable and influenced by complex interactions of perceptions, motives and attitudes. On the other hand, in the economic tradition preferences are primitive, consistent, and immutable (preference rationality), consumers behave as if they possess the formal tools with which to calculate the optimum adequately (perception-rationality), and the cognitive process is simply preference maximization, given market constraints (process-rationality). The models that we (transport researchers) currently use to describe how people choose among a discrete set of alternatives are based on these assumptions of rationality in preference, perception and process. McFadden’s work (1978; 1981) on Generalised Extreme Value (GEV) formulation, which generalised the work of Williams (1977), provides a rigorous foundation for consumer choice modelling derived from economic theory. Although the original formulation of the random utility maximisation (RUM) as a behavioural model followed the economists’ theory of consumer behaviour, it also included “features of the taste template that were heterogeneous across individuals and unknown to the analyst, as well as unobserved aspects of experience and of information on the attributes of alternatives, interpreted as random factors” (McFadden, 2000). This led to the paradigm for generating discrete-choice models (DCM), commonly reported in textbooks (Ben-Akiva and Lerman, 1985; Ortúzar and Willumsen, 2011; Train, 2009), that the random part of the individual utility reflects the modellers’ lack of complete information about all the elements considered by the individual making a choice, which might also include unobserved deviations of individual behaviour from perfect rationality. This paradigm posed the bases for the most important stream of research of the last 30 years. Since McFadden’s work, in fact, research activity in this field has been very proactive. Major progress has been made in exploring the potentiality of DCM to improve the ability to effectively reproduce individual behaviour. In particular, this paper draws attention to two streams of research motivated by this work. The first refers to the microeconomic justification of DCM and, in particular, of the utility individuals associate to each discrete alternative. The second stream, and maybe the most productive one, has been concerned with the characterization of the error terms, and in particular the exploitation of the mixed multinomial logit (MMNL) model. Research in both streams has aimed to improve the representation of the true phenomenon. However, the goal has always been that the measurable part of utility should be able to explain (as much as possible) the true behaviour in order to reduce the explanatory power left in the error term. This is correct except that, under the neo-classical theory, the systematic measurable utility was associated only with “rational” behaviour and what deviated from it was classified as error and hence minimised. Unfortunately, major improvements in model fit obtained with complex decompositions of the error term have given a strong signal that there are inherent limitations in the capability of microeconomic theory to explain individual choices and that we are still far from having a satisfactory representation (through known variables) of the real phenomenon. In fact, although RUM “takes a nod towards psychological theory” (Batley and Daly, 2006), the error term cannot be considered to properly explain behaviour that departs from perfect rationality. This is because errors are parameterized in terms of statistical distributions and the psychological concept of irrationality (i.e., not rational in the sense of neoclassical economic theory) is associated to the concept of randomness. As suggested by Ariely (2008), apparent irrationality can indeed be explained and predicted. Illustrious scholars (McFadden, 2000; Ben-Akiva, et al, 2002a) have strongly asserted the need to explore more seriously the suggestions provided by the psychological literature. After a shy start, the last decade has seen a surprising increase in the amount of work in this area (see for example Walker, 2001; Gärling and Axhausen, 2003; Bonsall, et al, 2007). Most of it has concentrated on demonstrating empirically that integrating psychology theory into the economic framework results in tangible improvement in terms of model fit, and interestingly most of it has been based on the MMNL structure. This is a key point, because the last years have also witnessed an increased awareness of the inherent limitations of the MMNL in terms of both estimation and especially prediction. In fact, notwithstanding the clear ability of this model to represent an ample range of behaviours via error term decomposition, several problems implicit in its structure have led analysts to lose confidence in the model. It is interesting then to understand whether or not these new models, which go beyond the rational postulate, still suffer from the above limitations or to what extent these are overcome. This paper presents a critical review of the research developments in the representation of the decision process, and it is structured into two parts. The first is dedicated to reviewing the limitations of the DCM and, in particular, of the MMNL model. Limits due to both the microeconomic theory of the rational user and the exploitation of the error terms will be critically discussed. The second part of the paper reviews research belonging to the non-rational theory. I concentrate on those advances that still rely heavily on the DCM with the aim to discuss to what extent we are really moving forward with respect to the above limitations of the classical MMNL model. Although focusing on research produced in the transport field, the paper provides and relies on several references from the literature in psychology and behavioural economics. Placing an accent on the limitations of current theory is not dictated by a pessimist view. On the contrary, it is intended as a proactive approach; these limitations constitute the starting point for and, above all, should stimulate new research. Another important consideration is that excellent reviews of both microeconomic theory (see McFadden, 2000; Bates, 2007; Jara-Díaz, 2007) and discrete choice models (see Ben-Akiva, et al, 2002b; Ortúzar, 2006; Bhat, 2007) already exist, while a review of their limitations seems yet to be undertaken; at least this is what emerges from research conducted over the last few years. The paper concludes by discussing some open questions raised by the research conducted so far and giving some final thoughts about the amazing challenge unfolding before us over the next years.<br/
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A Count Data Model with Endogenous Covariates: Formulation and Application to Roadway Crash Frequency at Intersections
No full textAt the time of publication Chandra R. Bhat, Kathryn Born, and Raghuprasad Sidharthan were at the University of Texas at Austin, and Prerna C. Bhat was at Harvard University.This paper proposes an estimation approach for count data models with endogenous covariates.
The maximum approximate composite marginal likelihood inference approach is used to
estimate model parameters. The modeling framework is applied to predict crash frequency at
urban intersections in Irving, Texas. The sample is drawn from the Texas Department of
Transportation (TxDOT) crash incident files for the year 2008. The results highlight the
importance of accommodating endogeneity effects in count models. In addition, the results
reveal the increased propensity for crashes at intersections with flashing lights, intersections with
crest approaches, and intersections that are on frontage roads.Civil, Architectural, and Environmental Engineerin
Chhapgarus intermedius Ng & Trivedi & Bhat 2022, comb. nov.
No full textChhapgarus intermedius (Chhapgar, 1955) comb. nov. (Figs. 1–6) Pseudograpsus intermedius Chhapgar, 1955: 257.— Chhapgar 1957: 519.— Hashmi 1964: 452.— Sethuramalingam & Khan 1991: 89.— Selvakumar & Khan 1993: 337.— Tirmizi & Ghani 1996: 170, fig. 65.— Chakraborty et al, 2002: 1392.— Khan et al. 2005: 1319.— Dev Roy & Nandi 2007: 180.— Ravichandran & Kannupandi 2007: 333 (in list).— Haragi et al. 2010: 10 (in list).— Dineshbabu et al, 2011: 23 (in list).— Pawar 2012: 90 (in list).— Trivedi et al. 2018: 75 (in list). Holotype: ZSI C3-363/1, male (CW 10.7 mm, CL 9.0 mm), Mumbai, Maharastra State, India, 17 March 1953, coll. B. F. Chhapgar. Other material examined: LFSC.ZRC-154, 8 males (CW 5.8–11.1 mm, CL 5.4–10.0 mm), 6 females (CW 6.1– 8.6 mm, CL 5.5–7.6 mm), Chapora Estuary (15°37′95″N, 73°45′76″E), Goa state, India, 7 September 2016, coll. M. Bhat; RMNH D-30417, 1 male (CW 11.3 mm, CL 10.4 mm), 1 female (CW 8.6 mm, CL 7.6 mm), Kali River estuary, Karnataka state, India, 1974–1975, coll. U. S. Kakati. Description. Carapace squarish, slightly broader than long; dorsal surface covered with short-brown setae, regions not well defined, convex. Frontal margin slightly convex, slightly bilobed (Figs. 1A, 2A, 4A, 5A, 6A). Anterolateral margin subcristate with three teeth, including orbital tooth, external orbital tooth most distinct, very broad; second tooth smaller in size, third tooth smallest. Posterolateral margins not sharply demarcated from anterolateral margin, almost straight, distinctly converging. Orbits small, eyes completely filling orbit (Figs. 1A, 2A, 4A, 5A, 6A). Third maxilliped with foliaceous merus, broader than long; anterolateral angle produced, auriculiform; distal margin distinctly bilobed, outer lobe larger, base with small median cleft. Ischium longer than broad, sulcus not discernible. Small, distinct rhomboidal gape formed when closed. Exopod with obtuse, blunt inner subdistal angle, flagellum prominent, longer than width of merus (Fig. 2D). Epistome broad, flat, posterior margin entire. Male chelipeds equal to subequal, inner surfaces glabrous; merus without spines, dorsal surface highly setose; carpus without spines or teeth; outer surface of fingers with tufts of long, soft setae. Fingers slightly shorter than palm; dactylus with one large tooth medially followed by small teeth, pollex cutting edge with small teeth, one large tooth present proximally, single prominent ridge present on pollex, finger tips recurved, sharp, hooved (Figs. 1A, B, 2B, 4B). Female chelae slender than those of male, outer surface covered with short setae, a prominent ridge running parallel to the ventral margin (Figs. 2C, 5B). Ambulatory legs with second pair longest. Merus of all ambulatory legs with long, soft setae; anterior margin with blunt subdistal tooth; outer surface of carpus with short setae, anterior and posterior margins of propodus with short setae (Figs. 1A, C, 3F–I, 4A, C, 5A, C, 6A, B). Male pleon narrowly triangular with all segments freely moveable (six somites plus telson), lateral margins highly setose (Figs. 1C, 2E, 4C, 6B); female pleon similar, very broad (Figs. 3A, 5B). G1 stout, gently curving outwards, terminal lobe elongate, slightly curved (Figs. 3B–D). G2 short, small (Fig. 3E). Female vulvae operculate, circular (Fig. 3J). Distribution. The species is so far reported from Pakistan (Tirmizi & Ghani 1996) and India (Trivedi et al. 2018). In India, the species is reported from Maharashtra (Chhapgar 1955, 1957; Pawar 2012), Karnataka (Haragi et al. 2010; Dineshbabu et al. 2011), and Tamil Nadu (Sethuramalingam & Khan 1991; Selvakumar & Khan 1993; Khan et al. 2005; Dev Roy & Nandi 2007; Ravichandran & Kannupandi 2007). Ecology. Chhapgarus intermedius comb. nov. inhabits the mid-intertidal zone in mangrove habitats. Individuals of the species are mostly found under dead logs or rock boulders, and sometimes also in burrows. Coloration. The carapace of fresh specimens is chestnut brown with short black setae. The cheliped and ambulatory legs are light brown. Sternum and abdomen are also light brown. Remarks. Chhapgarus intermedius (Chhapgar, 1955) comb. nov. was described on the basis of 14 specimens (ten males; two females and two ovigerous females) collected from Mumbai (Bombay), Maharashtra State, India (Chhapgar 1955). The holotype male, which was deposited in Zoological Survey of India, Kolkata has been examined in the present study but the rest of the specimens (paratype) examined by Chhapgar (1955) are not traceable. Fresh specimens examined in the present study show agreement with the illustrations and original descriptions given by Chhapgar (1955).Published as part of Ng, Ngan Kee, Trivedi, Jigneshkumar & Bhat, Mithila, 2022, Redescription of Pseudograpsus intermedius Chhapgar, 1955 (Decapoda, Brachyura, Varunidae) from India, pp. 127-138 in Zootaxa 5209 (1) on page 131, DOI: 10.11646/zootaxa.5209.1.7, http://zenodo.org/record/732261
Chhapgarus Ng & Trivedi & Bhat 2022, n. gen.
No full textChhapgarus n. gen. Type species. Pseudograpsus intermedius Chhapgar, 1955, by present designation. Description. Carapace squarish, dorsal surface covered with short, brown setae; regions well defined, convex; frontal margin slightly convex, straight; anterolateral margin subcristate with three teeth including first orbital tooth; posterolateral margins not sharply demarcated from anterolateral margin, concave at branchial region, distinctly subparallel; orbits small, eyes completely filling orbit. Third maxillipeds short, stout; small, distinct rhomboidal gape when closed, palp short, with short setae; exopod with short flagellum. Epistome broad, flat, posterior margin entire. Inner surface of chela with granules, setose. Ambulatory legs long, slender with short setae, stout dactyli. Lateral margins of thoracic sternites 4–5 finely granulated; anterior sternal plates without any medial grooves. Male pleon narrowly triangular, with 7 free segments (6 somites plus telson). Female pleon ovate, very broad. G1 stout, gently curving outwards, terminal lobe elongate, slightly curved. Etymology. The new genus is named in honor of Dr. Boman Framji Chhapgar for his valuable contributions to the study of crustacean fauna of Gujarat and Maharashtra States, India. Gender: masculine. Remarks. The description of the genus Pseudograpsus provided by H. Milne Edwards (1837) is brief that has been updated by Ng et al. (2002). In his description, H. Milne Edwards (1837: 81) named two species as belonging to the genus, Pseudograpsus viz. P. pencilliger (Latreille, 1817), and P. pallipes H. Milne Edwards, 1837. No type species was designated. Holthuis (1977) was the first to validly select Cancer penicilliger Latreille, 1817, as the type species (see also Ng & Nakasone 1993: 2). Cancer penicilliger was later synonymized under the senior name, Pseudograpsus setosus (see Ng et al. 2002). The genus Pseudograpsus has a long history of association with Hemigrapsus and Brachynotus (see Tesch 1918; McLay & Schubart 2004; Ng et al. 2002). This association is now being studied in-depth (in preparation). Balss (1934) synonymized P. erythraeus Kossmann, 1894, under P. elongatus. Ng & Nakasone (1993) transferred P. laniger to their new genus, Scutumara Ng & Nakasone, 1993, with a comment that the genus Pseudograpsus needs to be revised. The genus, Pseudograpsus, currently comprises of five species viz. P. setosus (Fabricius, 1778) (= P. pencilliger (Latreille, 1817), type species); P. crassus A. Milne-Edwards, 1868, P. albus Stimpson, 1858, P. elongatus A. Milne-Edwards, 1873, and P. intermedius Chhapgar, 1955. Out of these five species, P. intermedius varies from other species of Pseudograpsus s.s. in having setae on the carapace, chela having soft setae on outer surface, broad and stout ambulatory legs and differences in morphology of reproductive structures, hence Chhapgarus n. gen. is established for Pseudograpsus intermedius Chhapgar, 1955. Interestingly, C. intermedius comb. nov. inhabits the mid-intertidal zone in mangrove habitats (Chhapgar 1955), while species of Pseudograpsus s.s. are found in freshwater streams and/or under pebbles/coral sand habitats along beaches (Tesch 1918; Balss 1922; H.T. Shih, pers. comm). The morphological differences between Chhapgarus n. gen. and Pseudograpsus are given in Table 1. Chhapgarus n. gen., also shows similarity to Utica White, 1847 in having setae on the carapace surface and outer surface of chela, but differs from the latter in the following characters: carapace squarish (versus distinctly quadrangular in Utica); gastric region without “V” shaped ridge (versus prominent “V” shaped ridge on gastric region in Utica); branchial region without horizontal ridge (versus horizontal setose granulated ridge present across the branchial region in Utica).Published as part of Ng, Ngan Kee, Trivedi, Jigneshkumar & Bhat, Mithila, 2022, Redescription of Pseudograpsus intermedius Chhapgar, 1955 (Decapoda, Brachyura, Varunidae) from India, pp. 127-138 in Zootaxa 5209 (1) on page 130, DOI: 10.11646/zootaxa.5209.1.7, http://zenodo.org/record/732261
Spatial and frequency measurement optimization in Subsurface Imaging
No full textThis paper deals with microwave subsurface imaging for a multi-monostatic/multi-frequency configuration. The focus is on devising a suitable data sampling scheme that requires as low as possible data but preserves the achievable performance. To this end, we introduce two sampling schemes. The first one is based on analytical arguments subtended by the recently introduced warping approach. The second sampling method relies on a sensor selection procedure called maximal projection onto the minimum eigenspace. The two approaches are compared for different configuration parameters, and both show a dramatic data reduction as compared to sampling schemes commonly employed in literatur
A Multivariate Hurdle Count Data Model with an Endogenous Multiple Discrete- Continuous Selection System
No full textAt the time of publication Chandra R. Bhat, Subodh K. Dubey, and Raghuprasad Sidharthan were at the University of Texas at Austin, and Prerna C. Bhat was at Harvard University.This paper proposes a new econometric formulation and an associated estimation method for
multivariate count data that are themselves observed conditional on a participation selection
system that takes a multiple discrete-continuous model structure. This leads to a joint model
system of a multivariate count and a multiple discrete-continuous selection system in a hurdletype
model. The model is applied to analyze the participation and time investment of households
in out-of-home activities by activity purpose, along with the frequency of participation in each
selected activity. The results suggests that the number of episodes of activities as well as the time
investment in those activities may be more of a lifestyle- and lifecycle-driven choice than one
related to the availability of opportunities for activity participation.Civil, Architectural, and Environmental Engineerin
Why do they use bhat chew sticks? An experiment to demonstrate the antihyperglycemic activity of Clerodendrum infortunatum Linn.
No full textIntroduction: The rise in blood glucose than the recommended level is called hyperglycemia, mainly caused by diabetes mellitus (DM). DM is in turn a consequence of decreased insulin secretion or action or both. This experiment is intended to evaluate the effect of Clerodendrum infortunatum Linn. (bhat) chew sticks in controlling diabetes in humans. Method: The fasting blood sugar was measured twice with the help of a glucometer. First, all participants were requested to measure their blood sugar on an empty stomach in the morning without using a bhat chew stick. The next morning, their fasting plasma sugar was again accessed after the use of the bhat chew sticks as a toothbrush. The fall in blood sugar value was recorded and the efficiency of the stimulus was tested using student t-test at α level of significance and n-1 degree of freedom. Result: A total of 27 individuals participated in the study and all responded to the stimulus. A fall in blood glucose was observed between 3-59 mg/dL and the response was not found to be significant at 0.05 level of significance. Conclusion: Rural people use chew sticks as toothbrushes and prefer C. infortunatum twigs to control diabetes. The present experiment shows that bhat lowers the blood sugar level in both diabetic and non-diabetic individuals. However, chronic impacts should also be monitored by conducting large-scale studies on humans to establish proper dosage, indications, and side effects of C. infortunatum.
Keywords: Clerodendrum infortunatum, diabetes, hyperglycemia, random blood sugar, chew stick
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