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1.
Comput Ind Eng ; 176: 108893, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36532864

ABSTRACT

Amid the epidemic outbreaks such as COVID-19, a large number of patients occupy inpatient and intensive care unit (ICU) beds, thereby making the availability of beds uncertain and scarce. Thus, elective surgery scheduling not only needs to deal with the uncertainty of the surgery duration and length of stay in the ward, but also the uncertainty in demand for ICU and inpatient beds. We model this surgery scheduling problem with uncertainty and propose an effective algorithm that minimizes the operating room overtime cost, bed shortage cost, and patient waiting cost. Our model is developed using fuzzy sets whereas the proposed algorithm is based on the differential evolution algorithm and heuristic rules. We set up experiments based on data and expert experience respectively. A comparison between the fuzzy model and the crisp (non-fuzzy) model proves the usefulness of the fuzzy model when the data is not sufficient or available. We further compare the proposed model and algorithm with several extant models and algorithms, and demonstrate the computational efficacy, robustness, and adaptability of the proposed framework.

2.
Zootaxa ; 5138(5): 575-583, 2022 May 20.
Article in English | MEDLINE | ID: mdl-36095817

ABSTRACT

Invertebrates make up the majority of all living species on earth. Nevertheless, our understanding of the global distribution of terrestrial biodiversity and regional patterns therein has thus far been almost entirely based on vertebrate and vascular plant patterns. Here we try to provide some information on the global biogeography of the largest invertebrate order, the beetles (Coleoptera). We compile and analyse a database of beetle distributions, containing presence-absence data for 177 coleopteran families across 827 ecoregions. We map family richness and weighted endemism and find the highest values in the Neotropics and Southeast Asia, but also in the temperate northern hemisphere. Important centres of beetle family endemism include the western and southern parts of North America, Central America, temperate South America, Europe, South, Southeast and East Asia, and eastern Australia. A series of UPGMA cluster analyses were used to produce two global regionalisation maps. As analyses on the complete dataset failed to produce contiguous clusters, two sub-datasets were considered. The first one excluded widespread families and family-poor ecoregions, and the second was restricted to endemic-rich ecoregions. The clusters resulting from the first analysis are partly similar to vertebrate- and plant-based regionalisation schemes, with easily discernible and extensive Holarctic and Holotropical regions, but also include numerous smaller regions, mostly in the temperate parts of the southern Hemisphere (Andean, Patagonian, Matorral, New Guinean, New Caledonian, southern African), with Australia split between a tropical and a temperate/subtropical part. New Zealand is not analysed in this reduced dataset, but clusters with New Caledonia in the endemic-rich analysis, where further interesting subdivisions emerge (mainly in East Asia and western North America). We discuss these patterns in the light of coleopteran dispersal and the habitat requirements predominant across the coleopteran phylogeny, while considering the age of beetle families.


Subject(s)
Biodiversity , Plants , Animals , Ecosystem , Phylogeny , Vertebrates
3.
Ann Oper Res ; : 1-34, 2021 Mar 08.
Article in English | MEDLINE | ID: mdl-33716371

ABSTRACT

We study a two-echelon supply chain with two homogeneous manufacturers and one common retailer who has full knowledge about his own value-added service cost structure that is unknown to the manufacturers. The retailer may choose to disclose his cost information to the manufacturers. Using a three-stage game-theoretic model, we derive optimal pricing strategies for each participant, and optimal information sharing strategies, and the optimal level of the value-added services for the retailer. Our study also reveals when the manufacturers should accept the disclosed information by the retailer. It is shown that information sharing does not always create a win-win situation among the partners in the supply chain. When the value-added service cost efficiency is low, the retailer is willing to share complete information with the manufacturers; however, information sharing harms the manufacturers' profits if they accept the shared information. In contrast, when the value-added service cost efficiency is high, the common retailer has no incentive to share information with the manufacturers and the unique equilibrium is no information sharing. Finally, we utilize a revenue-sharing contract to achieve supply chain coordination and induce information sharing under asymmetric information.

4.
PLoS One ; 16(3): e0248040, 2021.
Article in English | MEDLINE | ID: mdl-33662026

ABSTRACT

Invertebrates in general have long been underrepresented in studies on biodiversity, biogeography and conservation. Boundaries of biodiversity hotspots are often delimited intuitively based on floristic endemism and have seldom been empirically tested using actual species distributions, and especially invertebrates. Here we analyse the zoogeography of terrestrial malacofauna from south-eastern Africa (SEA), proposing the first mollusc-based numerical regionalisation for the area. We also discuss patterns and centres of land snail endemism, thence assessing the importance and the delimitation of the Maputaland-Pondoland-Albany (MPA) biodiversity hotspot for their conservation. An incidence matrix compiled for relatively well-collected lineages of land snails and slugs (73 taxa in twelve genera) in 40 a priori operational geographic units was subjected to (a) phenetic agglomerative hierarchical clustering using unweighted pair-group method with arithmetic means (UPGMA), (b) parsimony analysis of endemicity (PAE) and biotic element analysis (BEA). Fulfilling the primary objective of our study, the UPGMA dendrogram provided a hierarchical regionalisation and identified five centres of molluscan endemism for SEA, while the PAE confirmed six areas of endemism, also supported by the BEA. The regionalisation recovers a zoogeographic province similar to the MPA hotspot, but with a conspicuous westward extension into Knysna (towards the Cape). The MPA province, centres and areas of endemism, biotic elements as well as the spatial patterns of species richness and endemism, support the MPA hotspot, but suggest further extensions resulting in a greater MPA region of land snail endemism (also with a northward extension into sky islands-Soutpansberg and Wolkberg), similar to that noted for vertebrates. The greater MPA region provides a more robustly defined region of conservation concern, with centres of endemism serving as local conservation priorities.


Subject(s)
Snails/physiology , Africa, Eastern , Animal Distribution , Animals , Biodiversity , Cluster Analysis , Conservation of Natural Resources , Snails/classification
5.
Article in English | MEDLINE | ID: mdl-33502284

ABSTRACT

Fish genetic resources and diversity are very important aspects of environmental management and fisheries and are vital for making decisions on their commercial exploitation as well as conservation. The snakehead fishes in the world have significant economic importance as food and ornamental fish. A clear understanding of species' taxonomic status and genetic diversity is important for the utilization and implementation of conservation and management practices. Channa orientalis is a snakehead endemic to Sri Lanka that is heavily utilized in the ornamental fish export trade. Its genetic diversity has not yet been fully understood and it is difficult to distinguish it from closely resembling species. Therefore, we examined the genetic diversity of C. orientalis and developed a DNA-based marker that permits accurate, low cost, and reliable identification of C. orientalis. Determination of genetic diversity was mainly carried out through genetic analysis of the mitochondrial cytochrome c oxidase subunit 1 (MT-CO1) gene. The development of the DNA-based marker for the identification of C. orientalis was done through Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) analysis. Our analyses confirmed the presence of two distinct genetically divergent and geographically separated lineages of C. orientalis in Sri Lanka. The fast cost-effective gel-based PCR-RFLP marker method developed by us was successful in diagnosing C. orientalis from its closely resembling species. Thus, we believe our findings on the cryptic diversity and diagnostic methods will have important implications for the conservation and management of this endemic species.


Subject(s)
Fishes , Genome, Mitochondrial , Animals , DNA , Fishes/classification , Fishes/genetics , Fresh Water , Polymorphism, Restriction Fragment Length , Sri Lanka
6.
J Health Organ Manag ; ahead-of-print(ahead-of-print)2020 Jun 24.
Article in English | MEDLINE | ID: mdl-32584524

ABSTRACT

PURPOSE: Providing care that is patient-centered is an important objective in the modern healthcare industry. Despite this objective, hospital inpatient case managers and the services they provide are evaluated routinely without including patients' perspectives. Therefore, the purpose of this study is to fill this research gap by using patient expectations and perceptions to assess the overall quality of and patient satisfaction with hospital case management services. DESIGN/METHODOLOGY/APPROACH: This paper investigates five dimensions of case management services - reliability, responsiveness, assurance, empathy and tangibles - and how they affect overall quality and patient satisfaction. Study surveys are based on the SERVQUAL instrument. Survey data from a cross-sectional sample of 67 inpatients are analyzed using principal component analysis, confirmatory factor analysis, GAP analysis and a predictive model. FINDINGS: The preliminary part of the study identifies "tangibles" and "nontangibles" - reliability, responsiveness, assurance and empathy - as the main components. Among these two components, only nontangibles have a positive and significant effect on both quality and patient satisfaction according to patient perspectives. GAP analysis indicates that gaps between patient expectations and perceptions of reliability and assurance are significant. Finally, the proposed predictive model reveals that gaps in assurance have a significant impact on both overall quality and satisfaction, while gaps in empathy have a significant impact on satisfaction, but not overall quality. ORIGINALITY/VALUE: Studies on service quality at the case manager level are limited. This study is the first in this domain to evaluate quality and satisfaction from the patient perspective.


Subject(s)
Case Management/standards , Patient-Centered Care , Quality of Health Care , Adolescent , Adult , Aged , Consumer Behavior , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Surveys and Questionnaires , Young Adult
8.
Zootaxa ; 4382(1): 56-92, 2018 Feb 20.
Article in English | MEDLINE | ID: mdl-29689938

ABSTRACT

We use numerical methods to explore patterns of vertebrate endemism in south-eastern Africa, refining the boundaries of the intuitively-defined Maputaland-Pondoland-Albany biodiversity hotspot, also proposing a zoogeographic regionalisation. An incidence matrix of 300 vertebrate species endemic to south-eastern Africa sensu lato in 37 operational geographic units were used in (a) phenetic cluster analysis (PCA) using the algorithm of unweighted pair-group method with arithmetic averages (phenetic approach), and (b) parsimony analysis of endemicity (PAE; parsimony approach), in order to numerically evaluate the bioregional delimitations. The analyses provide a valid biogeographical entity 37% larger than the Maputaland-Pondoland-Albany hotspot, but substantially (131%) higher in vertebrate endemicity viz. the Greater Maputaland-Pondoland-Albany (GMPA) region of vertebrate endemism. South-east Africa is recognised as a dominion in the global zoogeographical area hierarchy, with subordinate units including the GMPA province. Various spatially-based measures of endemism were mapped for vertebrate species restricted to the dominion, i.e. endemic to south-eastern Africa sensu stricto. Areas and centres of endemism detected respectively from PAE and PCA, within the south-east Africa dominion also support the refined boundary of the GMPA region of endemism, which provides a better spatial conservation priority compared to the Maputaland-Pondoland-Albany hotspot. Reptiles and amphibians are found to be the main drivers of the overall pattern of endemism, while the pattern in freshwater fish is the most distinctive. Our analyses also indicate a good congruence of the centres of endemism across different terrestrial vertebrate taxa.


Subject(s)
Amphibians , Biodiversity , Reptiles , Africa, Eastern , Animals , Conservation of Natural Resources , South Africa
9.
Biomed Res Int ; 2018: 8759459, 2018.
Article in English | MEDLINE | ID: mdl-30627580

ABSTRACT

INTRODUCTION: Limitations in breeding source reduction practices, development of insecticide resistance in mosquitoes, and ill effects of chemical controlling methods on human and ecosystem health have motivated Sri Lankan authorities working for dengue control to seek for alternative, ecofriendly, and sustainable approaches for controlling of Aedes vectors, to manage dengue epidemics. The present study attempted to investigate the predation efficiency of locally available dragonfly nymphs over Aedes aegypti under laboratory conditions, aiming to evaluate the potential of using dragonflies as biocontrol agents against dengue. METHODS: Nymphal stages of five locally abundant dragonfly species were collected from different stagnated water bodies in Belihuloya area. After morphological identification, a well grown individual of each species was starved for 12 hours and introduced into a glass tank containing 1L of pond water with 200 larvae (4th instar) of Aedes aegypti. Number of larvae survived in the tank was enumerated hourly up to 48 hours. In case where >75% of larvae are consumed by dragonfly nymphs, additional Ae. aegypti larvae were introduced into such tanks. Experiment was repeated for five times. Same procedure was followed with different stages of growth of the dragonfly nymphs characterized by the highest predation rate. General Linear Model followed by Tukey's pairwise comparison was used for statistical analysis. RESULTS: The predation rates of different dragonfly species varied significantly (p<0.05), whereby Anax indicus (110±7.14 per day) indicated the highest, followed by Pantala flavescens (54.07±5.15) and Gynacantha dravida (49.00±11.89), while Tholymis tillarga (23.47±2.48) had the lowest. Further, significant variations in the larval predation were found among different maturity stages (10-20; 25-35; and 35-45 mm in body length) of Ana. indicus (p<0.05). Regardless of statistical significance, a relatively higher larvicidal activity was observed at dusk than in dawn. Conclusion. Ana. indicus, which is characterized by the highest predation rate, and P. flavescens that has the widest geographical distribution within Sri Lanka along with a notable predation efficacy could be recommended as potential candidates for field trials in biological control of dengue outbreaks via suppression of Ae. aegypti larvae.


Subject(s)
Odonata/physiology , Pest Control, Biological , Aedes , Animals , Feeding Behavior , Larva/physiology , Species Specificity , Sri Lanka
10.
J Labelled Comp Radiopharm ; 59(3): 103-8, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26853088

ABSTRACT

Anaplastic lymphoma kinase (ALK), an oncogenic receptor tyrosine kinase, has emerged as a therapeutic target in solid and hematologic tumors. Although several ALK inhibitors have gained recent approval for therapy, non-invasive indicators of target engagement or for use as predictive biomarkers in vivo are lacking. Therefore, we designed and synthesized a radiolabeled analogue of the ALK inhibitor ceritinib, [(18)F]fluoroethyl-ceritinib ([(18)F]-FEC), for use with positron emission tomography. We used two methods to synthesize [(18)F]-FEC. First, [(18)F]fluoroethyl-tosylate was prepared, coupled with ceritinib, and the product purified to yield [(18)F]-FEC. Alternatively, a precursor compound was synthesized, directly fluorinated with (18)F-fluoride, and purified to yield [(18)F]-FEC. The first method produced [(18)F]-FEC with an average decay-corrected yield of 24% (n = 4), specific activity of 1200 mCi/µmol, and >99% purity; synthesis time was 115 min from the end of bombardment. The second method produced [(18)F]-FEC with an average yield of 7% (n = 4), specific activity of 1500 mCi/µmol, and >99% purity; synthesis time was 65 min from the end of bombardment. The synthesis of a novel (18)F-labeled analogue of ceritinib has been achieved in acceptable yields, at high purity, and with high specific activity. The compound is a potential positron emission tomography imaging agent for the detection of ALK-overexpressing solid tumors such as lung cancer.


Subject(s)
Fluorine Radioisotopes/chemistry , Protein Kinase Inhibitors/chemistry , Pyrimidines/chemistry , Pyrimidines/chemical synthesis , Radiopharmaceuticals/chemical synthesis , Sulfones/chemistry , Sulfones/chemical synthesis , Positron-Emission Tomography
11.
Sci Rep ; 5: 15457, 2015 Oct 26.
Article in English | MEDLINE | ID: mdl-26498226

ABSTRACT

The current distribution of biotic lineages that emerged in the deep time has both theoretical and practical implications, in particular for understanding the processes that have forged present-day biodiversity and informing local and regional-scale conservation efforts. To date however, there has been no examination of such patterns globally across taxa and geological time. Here we map the diversity of selected extant seed plant and tetrapod vertebrate lineages that were already in existence either in the latest Triassic or latest Cretaceous. For Triassic-age lineages, we find concentrations in several regions - both tropical and temperate - parts of North America, Europe, East and South-east Asia, northern South America, and New Zealand. With Cretaceous-age lineages, high values are relatively uniformly distributed across the tropics, with peak the values along the Andes, in South-east Asia and Queensland, but also in the temperate Cape Mountains. These patterns result from a combination of factors, including land area, geographic isolation, climate stability and mass extinction survival ability. While the need to protect many of these lineages has been long recognised, a spatially-explicit approach is critical for understanding and maintaining the factors responsible for their persistence, and this will need to be taken forward across finer scales.


Subject(s)
Climate , Plants , Animals
12.
J Org Chem ; 78(21): 10947-53, 2013 Nov 01.
Article in English | MEDLINE | ID: mdl-24106958

ABSTRACT

The List-Barbas-Mannich reaction of ethyl (p-methoxyphenylimino)acetate (p-methoxyphenyl = PMP) with unmodified aldehydes or ketones catalyzed by modularly designed organocatalysts (MDOs) that are self-assembled from proline and cinchona alkaloid thioureas (such as a quinidine-derived thiourea) produces the corresponding γ-oxo-α-amino acid derivatives in high yields and excellent stereoselectivities. No solvent is necessary for this reaction. Aldehydes are especially good substrates for this reaction: The reaction takes only a few minutes to yield the corresponding List-Barbas-Mannich products in excellent dr (up to >99:1) and ee values (up to >99% ee).

14.
Springerplus ; 1(1): 56, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23316449

ABSTRACT

UNLABELLED: Botanical work since 2008 on the Sleeping Giant section of the Kamdebooberge (Sneeuberg mountain complex, Eastern Cape, South Africa) has indicated that these mountains may be of significant conservation value. Accordingly, a precursory, rapid multi-disciplinary biodiversity assessment was undertaken in January 2011, focusing on plants, tetrapod vertebrates and leafhoppers. The botanical results confirm the Kamdebooberge as being of high botanical conservation value, hosting three strict endemics, healthy populations of five other Sneeuberg endemics, and fynbos communities comprising species not found elsewhere in the Sneeuberg. The Kamdebooberge are important for herpetofauna (excluding serpentoids) and mammals, hosting several range-restricted and regional endemics. The expedition uncovered three new leafhopper species, together with several species previously only known from the Cape Floristic Region. Further detailed faunal work may provide further interesting results from these mountains, which show a high conservation value unique to the southern Escarpment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/2193-1801-1-56) contains supplementary material, which is available to authorized users.

15.
Adv Synth Catal ; 353(10): 1729-1734, 2011 Jun 30.
Article in English | MEDLINE | ID: mdl-21918646

ABSTRACT

The cross aldol reaction between enolizable aldehydes and α-ketophosphonates was achieved for the first time by using 9-amino-9-deoxy-epi-quinine as the catalyst. ß-Formyl-α-hydroxyphosphonates were obtained in high to excellent enantioselectivities. The reaction works especially well with acetaldehyde, which is a tough substrate for organocatalyzed cross aldol reactions. The products were demonstrated to have anticancer activities.

16.
J Org Chem ; 75(4): 1101-6, 2010 Feb 19.
Article in English | MEDLINE | ID: mdl-20085234

ABSTRACT

Racemic alpha-acylphosphinates and formylphosphinate hydrate were used directly as the substrates in a proline derivative-catalyzed cross aldol reaction with ketones. Because of the preexisting phosphorus stereogenic center, a mixture of two diastereomers of the corresponding alpha-hydroxyphosphinates was obtained in this reaction. Good to high enantioselectivities (up to 99% ee) were obtained simultaneously for the two diastereomers in good yields. Good diastereoselectivities were also obtained when the reaction generates an additional carbon stereogenic center.


Subject(s)
Ketones/chemistry , Phosphinic Acids/chemical synthesis , Catalysis , Magnetic Resonance Spectroscopy , Molecular Structure , Phosphinic Acids/chemistry , Stereoisomerism
17.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 3): o569, 2010 Feb 10.
Article in English | MEDLINE | ID: mdl-21580337

ABSTRACT

In the title hydrate, C(18)H(20)BrO(4)P·H(2)O, a staggered conformation is found when the organic mol-ecule is viewed down the central P-C bond, with the oxo and hydroxyl groups being diagonally opposite; each of the central P and C atoms has an S-configuration. The crystal structure features supra-molecular double chains along the b axis mediated by O(hydrox-yl)-H⋯O(oxo), O(water)-H⋯O(oxo), and O(water)-H⋯O(water) hydrogen bonds.

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