Thermal performance of different roof and insulation systems in tropical thermal environments

Shelter has become one of the three basic needs of the human being. Shelter from natural elements such as rain, sun wind and heat had evolved the concept of the roof. The roof is not a contemporary product, but it is a result of many experiences and experiments of our forefathers. At the primitive stages they lived under trees, in large cavities of tree trunks, or in caves to protect them selves from the natural disasters. They started to build rough shelters when they were unable to find caves, during there rainy seasons. With passage of time and the civilization they felt the need to Seattle permanently. Under these circumstances their temporary structure was no longer an asset, but liability

Extension of the postharvest life of `Pollock' avocado using modified atmosphere packaging

Introduction. The postharvest life of `Pollock' avocado, a popular cultivar grown in Sri Lanka, is 7-10 d at room temperature. A short postharvest life limits its export volume by sea freight. Materials and methods. Pollock avocado fruit were packaged in 0.05 mm thick low-density polyethylene (LDPE) bags to create a modified atmosphere (MA), and they were stored at 12 °C and 94% relative humidity. The effect of the potassium permanganate, an ethylene absorber, and of the granular charcoal, a carbon dioxide absorber, on modifying the in-package atmosphere was tested. During storage, carbon dioxide, oxygen and ethylene contents were measured. The packages were opened after MA storage, and the fruit ripened naturally under ambient conditions. The weight loss, changes in firmness, total soluble solids (TSS), pulp color, visual quality rating (VQR), chilling injury index (CI) and disease index (DI) during or after storage were determined. Results. Compared with the samples packaged without absorbers, those packaged with absorbers had significantly lower carbon dioxide and ethylene contents. MA packaging was effective in extending the postharvest life of Pollock avocado up to 17 d. Inclusion of absorbers further extended the postharvest life up to 29 d. Firmness, TSS, pulp color, VQR, CI and DI of the ripened fruits were not significantly affected by the MA conditions. Discussion. The MA conditions did not alter the ripening process and were successful in preventing the chilling injury and diseases. Packaging of Pollock avocado in 0.05 mm LDPE bags at 1:1 surface to weight ratio (cm$^2\cdot$g-1) with ethylene and carbon dioxide absorbers and storing at 12 °C and 94% relative humidity can be recommended to extend their storage life up to 29 d

The role of histones in the immune responses of aquatic invertebrates

Histones are primary components of eukaryotic chromatin and highly abundant in all animal cells. In addition to their important role in chromatin structure and transcriptional regulation, histones contribute to innate immune responses. In several aquatic invertebrate species, as well as in many other invertebrate and vertebrate species, the transcripts for core histones are upregulated in response to immune challenge and exposure to environmental stressors. Histones show antimicrobial activity against bacteria and parasites in vitro and in vivo and have the ability to bind bacterial lipopolysaccharide and other pathogen-associated molecules. Several mechanisms regulating and facilitating the antimicrobial action of histones against pathogens have been described in vertebrate and some invertebrate species, including the production of Extracellular Traps (ETs) and the accumulation of histones in lipid droplets that can be selectively released in response to immune stimuli. Further studies are needed to determine the mechanisms of action of histones in immune responses in aquatic invertebrates and investigate the potential use of histones in the treatment of infectious diseases in aquaculture

Identification and expression of proteolysis-response genes for

Macrophthalmus japonicus is one of the most abundant macrobenthic animals in estuarine zone, which are transition areas between freshwater and marine environments. The crabs are potential bio-indicators reflecting aquatic sediment toxicity. So far, limited genetic research has focused on this group of animals largely due to the limited genomic information. In this study, we performed de novo transcriptome sequencing to produce the most comprehensive expressed sequence tag resource for M. japonicus, and identified stress response genes in M. japonicus exposed to antifouling biocides irgarol. Using 454 pyrosequencing, a total of 887 690 reads were obtained, which were assembled into 24 217 high-quality expressed sequence tags. These contigs were then clustered into 17 289 isotigs and further grouped into 12 923 isogroups. About 48% of the isogroups showed significant matches to known proteins based on sequence similarity. Moreover, irgarol toxicity induced up-regulation of stress response genes, associated with proteolysis and oxidation–reduction in biological process by Gene ontology analyses. Our data provide the most comprehensive transcriptome resource available for M. japonicus. This resource allowed us to identify genes associated with proteolysis processes, which facilitated the quantitative analysis of differential gene expression respond to irgarol toxicity. These data would provide foundation for future genetic and genomic studies of crustacean species and monitoring to freshwater as well as marine ecosystems.M. japonicas is one of the most abundant macrobenthic animals in estuarine zone. We performed de novo transcriptome sequencing to produce the most comprehensive EST resource for M. japonicas. We identified stress response genes in M. japonicus exposed to antifouling biocides irgarol. A total of 887,690 reads were obtained, which were assembled into 24,217 high quality ESTs using 454 pyrosequencing. Irgarol toxicity induced up-regulation of proteolysis and oxidation-reduction genes in biological process

Genome Characterization of Bacteriophage KPP-1, a Novel Member in the Subfamily <i>Vequintavirinae</i>, and Use of Its Endolysin for the Lysis of Multidrug-Resistant <i>Klebsiella variicola</i> In Vitro

Multidrug-resistant members of the Klebsiella pneumoniae complex have become a threat to human lives and animals, including aquatic animals, owing to the limited choice of antimicrobial treatments. Bacteriophages are effective natural tools available to fight against multidrug-resistant bacteria. The bacteriophage KPP-1 was found to be strictly lytic against K. variicola, a multidrug-resistant isolate, producing clear plaques. The genome sequence analysis of KPP-1 revealed that it comprised 143,369 base pairs with 47% overall GC content. A total of 272 genes (forward 161, complementary 111) encode for 17 tRNAs and 255 open reading frames (ORFs). Among them, 32 ORFs could be functionally annotated using the National Center for Biotechnology Information (NCBI) Protein Basic Local Alignment Search Tool (BLASTp) algorithm while 223 were found to code for hypothetical proteins. Comparative genomic analysis revealed that the closest neighbor of KPP-1 can be found in the genus Mydovirus of the subfamily Vequintavirinae. KPP-1 not only markedly suppressed the growth of the host but also worked synergistically with ampicillin. Useful genes for pathogen control such as endolysin (locus tag: KPP_11591) were found to have activity against multidrug-resistant isolate of K. variicola. Further studies are necessary to develop a strategy to control the emerging pathogen K. variicola using bacteriophages such as KPP-1

Marine Microalgae, Spirulina maxima-Derived Modified Pectin and Modified Pectin Nanoparticles Modulate the Gut Microbiota and Trigger Immune Responses in Mice

This study evaluated the modulation of gut microbiota, immune responses, and gut morphometry in C57BL/6 mice, upon oral administration of S. maxima-derived modified pectin (SmP, 7.5 mg/mL) and pectin nanoparticles (SmPNPs; 7.5 mg/mL). Metagenomics analysis was conducted using fecal samples, and mice duodenum and jejunum were used for analyzing the immune response and gut morphometry, respectively. The results of metagenomics analysis revealed that the abundance of Bacteroidetes in the gut increased in response to both modified SmP and SmPNPs (75%) as compared with that in the control group (66%), while that of Firmicutes decreased in (20%) as compared with that in the control group (30%). The mRNA levels of mucin, antimicrobial peptide, and antiviral and gut permeability-related genes in the duodenum were significantly (p &lt; 0.05) upregulated (&gt; 2-fold) upon modified SmP and SmPNPs feeding. Protein level of intestinal alkaline phosphatase was increased (1.9-fold) in the duodenum of modified SmPNPs feeding, evidenced by significantly increased goblet cell density (0.5 &plusmn; 0.03 cells/1000 &micro;m2) and villi height (352 &plusmn; 10 &micro;m). Our results suggest that both modified SmP and SmPNPs have the potential to modulate gut microbial community, enhance the expression of immune related genes, and improve gut morphology

Droplet Velocity in an Electrowetting on Dielectric Digital Microfluidic Device

In many electrowetting on dielectric (EWOD) based microfluidics devices, droplet actuation speed is a crucial performance-controlling parameter. Our present study aims to characterize and study droplet speed in a typical EWOD device. First, a practical droplet speed measurement method has been methodically demonstrated and some related velocity terms have been introduced. Next, influence of electrode shape on droplet speed has been studied and a new design to enhance droplet speed has been proposed and experimentally demonstrated. Instead of using square shaped electrodes, rectangular electrodes with smaller widths are used to actuate droplets. Additionally, different schemes of activating electrodes are studied and compared for the same applied voltage. The experiments show that a particular scheme of activating the array of rectangular electrodes enhances the droplet speed up to 100% in comparison to the droplet speed in a conventional device with square shaped electrodes

Accurate, consistent, and fast droplet splitting and dispensing in electrowetting on dielectric digital microfluidics

Abstract This letter reports two novel electrode design considerations to satisfy two very important aspects of EWOD operation—(1) Highly consistent volume of generated droplets and (2) Highly improved accuracy in the generated droplet volume. Considering the design principles investigated two novel designs were proposed; L-junction electrode design to offer high throughput droplet generation and Y-junction electrode design to split a droplet very fast while maintaining equal volume of each part. Devices of novel designs were fabricated and tested, and the results are compared with those of conventional approach. It is demonstrated that inaccuracy and inconsistency of droplet volume dispensed in the device with novel electrode designs are as low as 0.17 and 0.10%, respectively, while those of conventional approach are 25 and 0.76%, respectively. The dispensing frequency is enhanced from 4 to 9 Hz by using the novel design