Evolution of a Novel Appendage Ground Plan in Water Striders Is Driven by Changes in the Hox Gene Ultrabithorax

Water striders, a group of semi-aquatic bugs adapted to life on the water surface, have evolved mid-legs (L2) that are long relative to their hind-legs (L3). This novel appendage ground plan is a derived feature among insects, where L2 function as oars and L3 as rudders. The Hox gene Ultrabithorax (Ubx) is known to increase appendage size in a variety of insects. Using gene expression and RNAi analysis, we discovered that Ubx is expressed in both L2 and L3, but Ubx functions to elongate L2 and to shorten L3 in the water strider Gerris buenoi. Therefore, within hemimetabolous insects, Ubx has evolved a new expression domain but maintained its ancestral elongating function in L2, whereas Ubx has maintained its ancestral expression domain but evolved a new shortening function in L3. These changes in Ubx expression and function may have been a key event in the evolution of the distinct appendage ground plan in water striders

Ubx Regulates Differential Enlargement and Diversification of Insect Hind Legs

Differential enlargement of hind (T3) legs represents one of the hallmarks of insect evolution. However, the actual mechanism(s) responsible are yet to be determined. To address this issue, we have now studied the molecular basis of T3 leg enlargement in Oncopeltus fasciatus (milkweed bug) and Acheta domesticus (house cricket). In Oncopeltus, the T3 tibia displays a moderate increase in size, whereas in Acheta, the T3 femur, tibia, and tarsus are all greatly enlarged. Here, we show that the hox gene Ultrabithorax (Ubx) is expressed in the enlarged segments of hind legs. Furthermore, we demonstrate that depletion of Ubx during embryogenesis has a primary effect in T3 legs and causes shortening of leg segments that are enlarged in a wild type. This result shows that Ubx is regulating the differential growth and enlargement of T3 legs in both Oncopeltus and Acheta. The emerging view suggests that Ubx was co-opted for a novel role in regulating leg growth and that the transcriptional modification of its expression may be a universal mechanism for the evolutionary diversification of insect hind legs

Pogostick: A New Versatile piggyBac Vector for Inducible Gene Over-Expression and Down-Regulation in Emerging Model Systems

Non-traditional model systems need new tools that will enable them to enter the field of functional genetics. These tools should enable the exploration of gene function, via knock-downs of endogenous genes, as well as over-expression and ectopic expression of transgenes.We constructed a new vector called Pogostick that can be used to over-express or down-regulate genes in organisms amenable to germ line transformation by the piggyBac transposable element. Pogostick can be found at www.addgene.org, a non-profit plasmid repository. The vector currently uses the heat-shock promoter Hsp70 from Drosophila to drive transgene expression and, as such, will have immediate applicability to organisms that can correctly interpret this promotor sequence. We detail how to clone candidate genes into this vector and test its functionality in Drosophila by targeting a gene coding for the fluorescent protein DsRed. By cloning a single DsRed copy into the vector, and generating transgenic lines, we show that DsRed mRNA and protein levels are elevated following heat-shock. When cloning a second copy of DsRed in reverse orientation into a flanking site, and transforming flies constitutively expressing DsRed in the eyes, we show that endogenous mRNA and protein levels drop following heat-shock. We then test the over-expression vector, containing the complete cDNA of Ultrabithorax (Ubx) gene, in an emerging model system, Bicyclus anynana. We produce a transgenic line and show that levels of Ubx mRNA expression rise significantly following a heat-shock. Finally, we show how to obtain genomic sequence adjacent to the Pogostick insertion site and to estimate transgene copy number in genomes of transformed individuals.This new vector will allow emerging model systems to enter the field of functional genetics with few hurdles

Societal-level versus individual-level predictions of ethical behavior: a 48-society study of collectivism and individualism

Is the societal-level of analysis sufficient today to understand the values of those in the global workforce? Or are individual-level analyses more appropriate for assessing the influence of values on ethical behaviors across country workforces? Using multi-level analyses for a 48-society sample, we test the utility of both the societal-level and individual-level dimensions of collectivism and individualism values for predicting ethical behaviors of business professionals. Our values-based behavioral analysis indicates that values at the individual-level make a more significant contribution to explaining variance in ethical behaviors than do values at the societal-level. Implicitly, our findings question the soundness of using societal-level values measures. Implications for international business research are discussed

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Quality improvement of recycled concrete aggregate by removal of residual mortar : a comprehensive review of approaches adopted

With the goal of achieving sustainable development, numerous research studies have been conducted aimed at reducing construction and demolition waste for improving sustainability and environment and reducing greenhouse-gas emissions. Recycled concrete aggregate due to its residual adhered mortar has low specific gravity and high water absorption. Both of these impediments contribute in the increase of permeability and shrinkage, decrease in compressive strength and hence concrete quality produced from recycled concrete aggregate. Consequently, it is essential to improve the recycled concrete aggregate quality such that their properties become comparable with those of virgin aggregate. In order to improve the recycled concrete aggregate quality, researchers have adopted two main pathways: (1) removal of adhered mortar from aggregate grains and utilisation of the separated mortar, and (2) fortification of residual mortar to make it stronger, less permeable and hydrophobic. The present study focuses on the first pathway and aims to comprehensively review huge variety of treatment techniques available in the literature, which can be applied to enhance the recycled concrete aggregate quality, by removing maximum amount of the attached mortar, thereby increasing its density, reducing its water absorption, and subsequently producing high quality aggregate. In addition, the processes which can effectively utilise the removed mortar have been reviewed. The combination of both, separation of mortar from aggregate grains and its complete utilisation make these treatments economically viable. These treatments which are based on the published literature, have been individually analysed based on their applicability and efficacy

A review of recycled aggregate in concrete applications (2000–2017)

Solid waste has been an inevitable by-product of the operations of industrialised societies. One result of economic growth is an increase in generation of solid waste which normally was dumped in landfills and caused contamination of soil, water and air from toxic substances such as polychlorinated bi-phenyls (PCB’s), asbestos, construction chemicals, heavy metals, but the scarcity of land-filling areas, industrial growth as well as strict environmental regulations in developed and developing economies has led to the global re-assessment of the methods employed to recycle and utilise construction and demolition (C&D) waste as recycled aggregate for civil engineering projects i.e. construction and infrastructure development. Depending on their quality, recycled aggregate produced from C&D waste can be employed in various civil engineering works, which can help in a long way the economic and environmental sustainability of respective countries. With further research and development into overcoming technical as well as market barriers, considerable increase in recovery rates can be achieved with the existing technologies in developed economies. The main aim of this study is to review the literature on the production and utilisation of recycled aggregate in concrete, concrete pavements, roadway construction, and other civil engineering works and some discussion on the savings on CO2 emissions have been included. The globally published data on recycled aggregate standards (normative documents) of various countries have been systematically analysed and evaluated, and some barriers mentioned. This review may help to alleviate the concerns of consumers and encourage and further promote the use of recycled aggregate on a larger scale in civil engineering projects

Deformation and permeability of recycled aggregate concrete : a comprehensive review

Properties of recycled aggregate concrete (RAC) were found to be dependent on the source, its composition and consistent quality of demolished concrete waste. Many studies have shown that using recycled aggregate (RA) in concrete suffers from strength and durability problems caused mainly due to relatively porous residual mortar adhered on the surface of aggregate grains resulting in high water absorption and increase in permeability and shrinkage. Also, the weaker interfacial transition zone (ITZ) of about 20–50 μm thickness in-between mortar and aggregate particles plays important role in reducing the bond strength between RA and fresh concrete, hence the physical and mechanical properties of RAC are usually inferior than virgin aggregate concrete (VAC). This review paper focuses on two main characteristics of RAC: (a) deformation (shrinkage and creep); and (b) permeability (carbonation, chloride ingress and air and water penetration) which have a direct effect on the durability of RAC and recommends methods for the mitigation of their adverse effects. The effects of mineral admixtures, water to cement (w/c) ratio, and high-range (HR) superplasticisers on the durability properties of RAC have been reviewed. This research showed that a very meager number of authors (only 12 publications) have focused on both the essential durability characteristics i.e., deformation and permeability together; therefore, we feel a need to present a review focusing on both of these essential properties

PVDF sensor design and FPGA implementation of ultrasound power measurement

Ultrasound devices provide either diagnostic or therapeutic purpose in biomedical application. To avoid unwanted power exposure to the patient for safety concern but at the same time maintaining optimum diagnostic and therapeutic effect, ultrasound power meter is used to measure and calibrate the output power and intensity of the ultrasound machine. Most of the current ultrasound power meters are limited for either high power therapeutic or low power diagnostic purposes but not both and it is expensive. To enable Polyvinylidene fluoride (PVDF) for low cost ultrasound power meter, a robust low cost casing has been designed for optimum ultrasound power capturing from both therapeutic and diagnostic ultrasound machine. The system has been designed to minimize interference effect and noise, as well as to stabilize mechanical construction of the sensor. This paper presents a PVDF sensor design of an ultrasound power measurement system that is compact and simple in construction, easy and user friendly, but at the same time provides a reliable power measurement result. The power meter is designed using PVDF sensor and Altera Cyclone II Field Programmable Gate Array (FPGA) technology. Results show that this in-house power measurement system is able to measure 0.5 MHz - 10 MHz of the frequency range and 1 mW/cm2 to 10 W/cm2 of the intensity range