786 research outputs found
A new record of deep-sea caridean shrimp Heterocarpus chani (Decapoda: Pandalidae) from the southern coast of India
Heterocarpus genus belong to the family
Pandalidae (Decapoda, Caridea) which are common
in deeper waters. Some species are of commercial
value or fishery potential by their large size. They
are characterized by rostrum armed with teeth on
both margins; carapace with postrostral carina
extending nearly to posterior margin and with 1 or
more longitudinal lateral carinae; pereopods with
2nd pair distinctly unequal and dissimilar. The species
Heterocarpus chani was recorded from various
fishing harbours on the south coast (Sakthikulangara
Fishing Harbour; Kalamuku Landing centre (Kerala)
and the Thoothukudi and Nagapattinam Fisheries
Harbours Tamil Nadu) from the deep-sea catches
taken at depth of 200 – 350 m
Plesionika reflexa - a new record of deep-sea caridean shrimp from the southwest coast of India
Plesionika reflexa, Chace, 1985 (Decapoda:
Pandalidae) was recorded from the catch of deep
sea shrimp trawlers operated at a depth of 200-300
m off Sakthikulangara (8°56’60.78"N / 76°32’
34.27"E), Kollam south-west coast of India. The
ovigerous female [Carapace length (CL): 15mm;
Rostrum length (RL): 28mm] was reddish in colour
with dark red ring formation in posterior abdomen
Distribution of Plesionika semilaevis along the southwest coast of India
The commercial deep-sea caridean shrimp
Plesionika martia (A. Milne-Edwards, 1883) has long
been recorded from India and constitutes an
important part of catches of the deep-sea shrimp
fisheries. A recent survey in some deep-sea fishing
harbours along the south-west coast of India,
however, revealed that all material previously
reported as 'P. martia' is actually a misidentification
of its closely related species Plesionika
semilaevis Spence Bate, 1888
Plesionika persica (Kemp, 1925) and P. reflexa Chace, 1985 (Crustacea: Decapoda: Pandalidae) from India
The availability of Indian specimens of Plesionika persica (Kemp, 1925) and P. reflexa Chace, 1985 provided more information on the taxonomy around these two species. Moreover, it is the first record of P. persica to India. Although P. taiwanica Chan and Yu, 2000 is superficially rather similar to P. persica, there are many differences between them and probably it is inappropriate to establish a species group for these two species. It is likely that all previous records of P. ensis (A. Milne-Edwards, 1881) from India actually represent P. reflexa Chace, 1985. Nevertheless, the present Indian specimens of P. reflexa have more than 10% COI sequence divergence from the topotypic materials of both P. ensis and P. reflexa, and the epipods at the pereiopods III and IV reduced or absent. This data further highlights the confusing taxonomy in the "P. ensis" grou
A new record of deep-sea caridean shrimp Plesionika narval (Decapoda: Pandalidae) from the south west coast of India
Pandalid shrimp, Plesionika narval (Fabricius,
1787) was recorded from trawl fishing off Kochi
(9°59’ N 76°14’E), Kerala, south-west coast of India.
The specimens were obtained from deep-sea shrimp
trawlers operated at a depth range of 250-300 m.
Samples were collected from the Kalamuku Landing
Centre on 4th April 2014. 14 males and 12 females
in good condition were segregated from the mixed
deep-sea shrimp doscards and their measurements
recorded (Table 1). Body was transparently pinkred
in colour with a pair of sub dorsal and lateral
red margined white stripes extending along almost
entire body length from anterior carapace to
posterior abdomen
Branch and Price Solution Approach for Order Acceptance and Capacity Planning in Make-to-Order Operations
The increasing emphasis on mass customization, shortened product lifecycles, synchronized supply chains, when coupled with advances in information system, is driving most firms towards make-to-order (MTO) operations. Increasing global competition, lower profit margins, and higher customer expectations force the MTO firms to plan its capacity by managing the effective demand. The goal of this research was to maximize the operational profits of a make-to-order operation by selectively accepting incoming customer orders and simultaneously allocating capacity for them at the sales stage. For integrating the two decisions, a Mixed-Integer Linear Program (MILP) was formulated which can aid an operations manager in an MTO environment to select a set of potential customer orders such that all the selected orders are fulfilled by their deadline. The proposed model combines order acceptance/rejection decision with detailed scheduling. Experiments with the formulation indicate that for larger problem sizes, the computational time required to determine an optimal solution is prohibitive. This formulation inherits a block diagonal structure, and can be decomposed into one or more sub-problems (i.e. one sub-problem for each customer order) and a master problem by applying Dantzig-Wolfe’s decomposition principles. To efficiently solve the original MILP, an exact Branch-and-Price algorithm was successfully developed. Various approximation algorithms were developed to further improve the runtime. Experiments conducted unequivocally show the efficiency of these algorithms compared to a commercial optimization solver. The existing literature addresses the static order acceptance problem for a single machine environment having regular capacity with an objective to maximize profits and a penalty for tardiness. This dissertation has solved the order acceptance and capacity planning problem for a job shop environment with multiple resources. Both regular and overtime resources is considered. The Branch-and-Price algorithms developed in this dissertation are faster and can be incorporated in a decision support system which can be used on a daily basis to help make intelligent decisions in a MTO operation
The adult heart responds to increased workload with physiologic hypertrophy, cardiac stem cell activation, and new myocyte formation
Aims It is a dogma of cardiovascular pathophysiology that the increased cardiac mass in response to increased workload is produced by the hypertrophy of the pre-existing myocytes. The role, if any, of adult-resident endogenous cardiac stem/progenitor cells (eCSCs) and new cardiomyocyte formation in physiological cardiac remodelling remains unexplored. Methods and results In response to regular, intensity-controlled exercise training, adult rats respond with hypertrophy of the pre-existing myocytes. In addition, a significant number (∼7%) of smaller newly formed BrdU-positive cardiomyocytes are produced by the exercised animals. Capillary density significantly increased in exercised animals, balancing cardiomyogenesis with neo-angiogenesis. c-kitpos eCSCs increased their number and activated state in exercising vs. sedentary animals. c-kitpos eCSCs in exercised hearts showed an increased expression of transcription factors, indicative of their commitment to either the cardiomyocyte (Nkx2.5pos) or capillary (Ets-1pos) lineages. These adaptations were dependent on exercise duration and intensity. Insulin-like growth factor-1, transforming growth factor-β1, neuregulin-1, bone morphogenetic protein-10, and periostin were significantly up-regulated in cardiomyocytes of exercised vs. sedentary animals. These factors differentially stimulated c-kitpos eCSC proliferation and commitment in vitro, pointing to a similar role in vivo. Conclusion Intensity-controlled exercise training initiates myocardial remodelling through increased cardiomyocyte growth factor expression leading to cardiomyocyte hypertrophy and to activation and ensuing differentiation of c-kitpos eCSCs. This leads to the generation of new myocardial cells. These findings highlight the endogenous regenerative capacity of the adult heart, represented by the eCSCs, and the fact that the physiological cardiac adaptation to exercise stress is a combination of cardiomyocyte hypertrophy and hyperplasia (cardiomyocytes and capillaries)
Resampling methods for parameter-free and robust feature selection with mutual information
Combining the mutual information criterion with a forward feature selection
strategy offers a good trade-off between optimality of the selected feature
subset and computation time. However, it requires to set the parameter(s) of
the mutual information estimator and to determine when to halt the forward
procedure. These two choices are difficult to make because, as the
dimensionality of the subset increases, the estimation of the mutual
information becomes less and less reliable. This paper proposes to use
resampling methods, a K-fold cross-validation and the permutation test, to
address both issues. The resampling methods bring information about the
variance of the estimator, information which can then be used to automatically
set the parameter and to calculate a threshold to stop the forward procedure.
The procedure is illustrated on a synthetic dataset as well as on real-world
examples
Sex differences in nucleus accumbens transcriptome profiles associated with susceptibility versus resilience to subchronic variable stress
Depression and anxiety disorders are more prevalent in females, but the majority of research in animal models, the first step in finding new treatments, has focused predominantly on males. Here we report that exposure to subchronic variable stress (SCVS) induces depression-associated behaviors in female mice, whereas males are resilient as they do not develop these behavioral abnormalities. In concert with these different behavioral responses, transcriptional analysis of nucleus accumbens (NAc), a major brain reward region, by use of RNA sequencing (RNA-seq) revealed markedly different patterns of stress regulation of gene expression between the sexes. Among the genes displaying sex differences was DNA methyltransferase 3a (Dnmt3a), which shows a greater induction in females after SCVS. Interestingly, Dnmt3a expression levels were increased in the NAc of depressed humans, an effect seen in both males and females. Local overexpression of Dnmt3a in NAc rendered male mice more susceptible to SCVS, whereas Dnmt3a knock-out in this region rendered females more resilient, directly implicating this gene in stress responses. Associated with this enhanced resilience of female mice upon NAc knock-out of Dnmt3a was a partial shift of the NAc female transcriptome toward the male pattern after SCVS. These data indicate that males and females undergo different patterns of transcriptional regulation in response to stress and that a DNA methyltransferase in NAc contributes to sex differences in stress vulnerability
Chromosomal-level assembly of the Asian Seabass genome using long sequence reads and multi-layered scaffolding
We report here the ~670 Mb genome assembly of the Asian seabass (Lates calcarifer), a tropical marine teleost. We used long-read sequencing augmented by transcriptomics, optical and genetic mapping along with shared synteny from closely related fish species to derive a chromosome-level assembly with a contig N50 size over 1 Mb and scaffold N50 size over 25 Mb that span ~90% of the genome. The population structure of L. calcarifer species complex was analyzed by re-sequencing 61 individuals representing various regions across the species' native range. SNP analyses identified high levels of genetic diversity and confirmed earlier indications of a population stratification comprising three clades with signs of admixture apparent in the South-East Asian population. The quality of the Asian seabass genome assembly far exceeds that of any other fish species, and will serve as a new standard for fish genomics
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