Recent Submissions

  • The taxonomic history of Indo-Papuan groundsnakes, genus Stegonotus Duméril et al., 1854 (Colubridae), with some taxonomic revisions and the designation of a neotype for S. parvus (Meyer, 1874)

    Kaiser, Christine; Kaiser, Hinrich; O'Shea, Mark (Magnolia Press, 2018-07-16)
    Since its conceptualization in 1854, 29 species of the colubrid genus Stegonotus have been recognized or described, of which 15 (admiraltiensis, batjanensis, borneensis, cucullatus, derooijae, diehli, florensis, guentheri, iridis, heterurus, melanolabiatus, modestus, muelleri, parvus, poechi) are still considered valid today. Original species descriptions for the members of this genus were published in Dutch, English, French, German, and Italian and, perhaps as a consequence of these polyglot origins, there has been a considerable amount of confusion over which species names should be applied to which populations of Stegonotus throughout its range across Borneo, the Philippines, Wallacea, New Guinea, Australia, and associated archipelagos. In addition, the terminology used to notate characteristics in the descriptions of these forms was not uniform and may have added to the taxonomic confusion. In this paper, we trace in detail the history of the type specimens, the species, and the synonyms currently associated with the genus Stegonotus and provide a basic, species-specific listing of their characteristics, derived from our examination of over 1500 museum specimens. Based on our data, we are able to limit the distribution of S. modestus to the islands of Ambon, Buru, and Seram in the central Moluccas of Indonesian Wallacea. We correct the type locality of S. cucullatus to the Manokwari area on the Bird’s Head Peninsula of West Papua, Indonesian New Guinea and designate a neotype for S. parvus, a species likely to be a regional endemic in the Schouten Archipelago of Cenderawasih Bay (formerly Geelvink Bay), Indonesian New Guinea. We unequivocally identify and explain the problematic localities of the type specimens of S. muelleri and Lycodon muelleri, which currently reside in the same specimen jar. We remove L. aruensis and L. lividum from the synonymy of S. modestus and recognize them as S. aruensis n. comb. and S. lividus n. comb., respectively. We remove S. keyensis and Zamenophis australis from the synonymy of S. cucullatus and recognize them as S. keyensis n. comb. and S. australis n. comb., respectively. We further remove S. reticulatus from the synonymy of S. cucullatus, S. dorsalis from the synonymy of S. diehli, and S. sutteri from the synonymy of S. florensis. We designate lectotypes for S. guentheri, S. heterurus, S. lividus, and S. reticulatus. Lastly, we introduce S. poechi, a valid species not mentioned in the scientific literature since its description in 1924. This brings the diversity in the genus Stegonotus to 22 species. We also caution that in a complex group of organisms like Stegonotus any rush to taxonomic judgment on the basis of molecular and incomplete morphological data sets may perpetuate errors and introduce incongruities. Only through the careful work of connecting type material with museum specimens and molecular data can the taxonomy and nomenclature of complex taxa be stabilized.
  • Metamaterial Superlenses Operating at Visible Wavelength for Imaging Applications

    Haxha, Shyqyri; AbdelMalek, Fathi; Ouerghi, Faouzi; Charlton, Martin; Aggoun, Amar; Fang, Xu (Nature Research, 2018-10-31)
    In this paper, a novel design for a metamaterial lens (superlens) based on a Photonic Crystal (PC) operating at visible wavelengths is reported. The proposed superlens consist of a gallium phosphide (GaP) dielectric slab waveguide with a hexagonal array of silver rods embedded within the GaP dielectric. In-house 2DFDTD numerical method is used to design and optimize the proposed superlens. Several superlenses are designed and integrated within a same dielectric platform, promoting the proof-of-concept (POC) of possible construction of an array of superlenses (or sub-lenses to create an M-Lens) for light field imaging applications. It is shown that the concavity of the superlens and positioning of each sub-lens within the array strongly affects the performances of the image in terms of resolution. Defects and various geometrical shapes are introduced to construct and optimize the proposed superlenses and increase the quality of the image resolution. It is shown that the orientation of the active region (ellipse) along x and y axis has tremendous influence on the quality of image resolution. In order to investigate the performance characteristics of the superlenses, transmitted power is calculated using 2D FDTD for image projections at various distances (in x and y plane). It is also shown, how the proposed superlens structures could be fabricated using standard micro fabrication techniques such as electron beam lithography, inductively coupled Reactive ion etching, and glancing angle evaporation methods. To the best of our knowledge, these are the first reported POC of superlenses, integrated in a monolithic platform suitable for high imaging resolution that can be used for light field imaging applications at visible wavelength. The proposed superlenses (integrated in a single platform M-Lens) will have tremendous impact on imaging applications.
  • Tweeting links to academic articles

    Thelwall, M.; Tsou, A.; Weingart, S.; Haustein, S. (2013-01-01)
    Academic articles are now frequently tweeted and so Twitter seems to be a useful tool for scholars to use to help keep up with publications and discussions in their fields. Perhaps as a result of this, tweet counts are increasingly used by digital libraries and journal websites as indicators of an article's interest or impact. Nevertheless, it is not known whether tweets are typically positive, neutral or critical, or how articles are normally tweeted. These are problems for those wishing to tweet articles effectively and for those wishing to know whether tweet counts in digital libraries should be taken seriously. In response, a pilot study content analysis was conducted of 270 tweets linking to articles in four journals, four digital libraries and two DOI URLs, collected over a period of eight months in 2012. The vast majority of the tweets echoed an article title (42%) or a brief summary (41%). One reason for summarising an article seemed to be to translate it for a general audience. Few tweets explicitly praised an article and none were critical. Most tweets did not directly refer to the article author, but some did and others were clearly self-citations. In summary, tweets containing links to scholarly articles generally provide little more than publicity, and so whilst tweet counts may provide evidence of the popularity of an article, the contents of the tweets themselves are unlikely to give deep insights into scientists' reactions to publications, except perhaps in special cases.
  • A Guide to the snakes of Papua New Guinea: The first comprehensive guide to the snake fauna of Papua New Guinea

    O'Shea, Mark (Independent Publishing, 1996-11-02)
    A complete guide to the snakes of the island of New Guinea (with particular emphasis on the eastern half constituting the sovereign state of Papua New Guinea) and the islands to the east, e.g. Bismarck, Admiralty, d'Entrecasteaux, Louisiade and North Solomons Archipelagoes. Although out of print and also now out of date, this is still the definitive and much sought guide to the snake fauna of this region. It includes a section of snakebite first aid and hospital treatment by Drs David A Warrell and David G Lalloo.
  • The Book of snakes

    O'Shea, Mark (Ivy Press, 2018-10-11)
    There are over 3,700 species of snake found on every continent except for Antarctica, ranging in size from Barbados’ tiny threadsnake to Southeast Asia’s massive reticulated python. More than any other creature snakes are surrounded by dark, compelling myths and legend, unsurprising since many constrict their prey to death, or kill with a venomous bite, using a diverse armory of venoms that affect the blood, tissues, organs, and respiration. However, it is especially true of snakes that the closer you observe them, the more exquisite they are in their intricate geometry of pattern, the fine texture of the overlapping scales, and the intricacies of their multifarious lifestyles. The Book of Snakes profiles 600 significant species from all 32 families—one in six of all known species—to create a beautiful collector’s piece that is both a significant resource for enthusiasts and scholars, and the most visually stimulating guide on the market.
  • Ending the drought: New strategies for improving the flow of affordable, effective antivenoms in Asia and Africa

    Williams, David J.; Gutiérrez, José-María; Calvete, Juan J.; Wüster, Wolfgang; Ratanabangangkoon, Kavi; Paiva, Owen; Brown, Nicholas I.; Casewell, Nicholas R.; Harrison, Robert A.; Rowley, Paul, D.; O'Shea, Mark; Jensen, Simon D.; Winkel, Kenneth D.; Warrell, David A. (Elsevier, 2011-08-24)
    The development of snake antivenoms more than a century ago should have heralded effective treatment of the scourge of snakebite envenoming in impoverished, mostly rural populations around the world. That snakebite still exists today, as a widely untreated illness that maims, kills and terrifies men, women and children in vulnerable communities, is a cruel anachronism. Antivenom can be an effective, safe and affordable treatment for snakebites, but apathy, inaction and the politicisation of public health have marginalized both the problem (making snakebite arguably the most neglected of all neglected tropical diseases) and its solution. For lack of any coordinated approach, provision of antivenoms has been pushed off the public health agenda, leading to an incongruous decline in demand for these crucial antidotes, excused and fed by new priorities, an absence of epidemiological data, and a poor regulatory framework. These factors facilitated the infiltration of quality products that degrade user confidence and undermine legitimate producers. The result is that tens of thousands are denied an essential life-saving medicine, allowing a toll of human suffering that is a summation of many individual catastrophes. No strategy has been developed to address this problem and to overcome the intransigence and inaction responsible for the global tragedy of snakebite. Attempts to engage with the broader public health community through the World Health Organisation (WHO), GAVI, and other agencies have failed. Consequently, the toxinology community has taken on a leadership role in a new approach, the Global Snakebite Initiative, which seeks to mobilise the resources, skills and experience of scientists and clinicians for whom venoms, toxins, antivenoms, snakes and snakebites are already fields of interest. Proteomics is one such discipline, which has embraced the potential of using venoms in bio-discovery and systems biology. The fields of venomics and antivenomics have recently evolved from this discipline, offering fresh hope for the victims of snakebites by providing an exciting insight into the complexities, nature, fundamental properties and significance of venom constituents. Such a rational approach brings with it the potential to design new immunising mixtures from which to raise potent antivenoms with wider therapeutic ranges. This addresses a major practical limitation in antivenom use recognised since the beginning of the 20th century: the restriction of therapeutic effectiveness to the specific venom immunogen used in production. Antivenomic techniques enable the interactions between venoms and antivenoms to be examined in detail, and if combined with functional assays of specific activity and followed up by clinical trials of effectiveness and safety, can be powerful tools with which to evaluate the suitability of current and new antivenoms formeeting urgent regional needs.We propose two mechanisms through which the Global Snakebite Initiative might seek to end the antivenom drought in Africa and Asia: first by establishing amultidisciplinary,multicentre, international collaboration to evaluate currently available antivenoms against the venoms of medically important snakes from specific nations in Africa and Asia using a combination of proteomic,antivenomic and WHO-endorsed preclinical assessment protocols, to provide a validated evidence base for either recommending or rejecting individual products; and secondly by bringing the power of proteomics to bear on the design of new immunising mixtures to raise Pan-African and Pan-Asian polyvalent antivenoms of improved potency and quality. These products will be subject to rigorous clinical assessment. We propose radically to change the basis upon which antivenoms are produced and supplied for the developing world. Donor funding and strategic public health alliances will be sought to make it possible not only to sustain the financial viability of antivenom production partnerships, but also to ensure that barrier to the treatment of this important, but grossly neglected public health emergency.
  • Courtship entanglements: a first report of mating behavior and sexual dichromatism in the Southeast Asian keel-bellied whipsnake, Dryophiops rubescens

    Kaiser, Hinrich; Johnny, Kim; O'Shea, Mark (Herpetology Notes, 2012-09-01)
    We describe the first observations of courtship behavior and sexual dichromatism in the keel-bellied whipsnake, Dryophiops rubescens, from an encounter near Sandakan, eastern Sabah, Borneo, Malaysia. During this behavior, two males and a female were longitudinally intertwined, with the males jockeying for position along the body of the female. This “mating braid” lasted for well over 1 h, with the entwined snakes moving a distance of over 10 m together. While polygynous mating is known from other snake species, direct observations of mating behaviors in Southeast Asian colubrids are extremely rare. These observations also revealed the presence of sexual dichromatism in D. rubescens, with darker head coloration present in the males.
  • Heavy metal removal using alkali activated kaolinite in the Cao-Al2O3-Sio2- H2O system

    Rios, Carlos A; Williams, Craig D; Fullen, Michael (MedCrave, 2017-11-30)
    The transformation of kaolinite was examined at 175°C for 24 h in the CaO-Al2O3- SiO2-H2O (CASH) system, which is important in cement science and especially in, cement chemistry and is closely related to the pozzolanic reaction, the CaO-aggregate reaction and the glass fibre reinforcement of hardened cement. The hydration products were characterized by X-ray diffraction, scanning electron microscopy, Fourier transformed infrared spectroscopy, Magic Angle Spinning Nuclear Magnetic Resonance and thermogravimetric analysis in order to elucidate their mineral chemistry and microstructure. Results reveal that several poorly crystalline phases were formed, with un-reacted Ca(OH)2 appearing at shorter reaction times. Hydrogarnet tends to form more rapidly than tobermorite. It was transformed into aluminium-substituted tobermorite with curing time. A batch experimental study confirmed that kaolinitebased calcium silicate hydrates are effective for the treatment of acid mine drainage, particularly in removing metal ions and ammonium
  • Academic anxiety and its effects on academic performance

    Mirawdali, Shangal; Morrissey, Hana; Ball, Patrick (International Journal of Current Research, 2018-06-28)
    Academic anxiety is a well-established, significant predictor of academic performance. Students with high levels of anxiety are unable to perform at the best of their ability. The purpose of this study was to determine the extent of academic anxiety and its effects on academic performance and explore if social and family sources of anxiety have effects on academic performance. This was a cross-sectional study design utilising questionnaire based on pre-validated tools was used to determine the extent of academic anxiety and evaluate its effect on students with high and low academic performance. A sample of 132 pharmacy undergraduates from stages 3 and 4 enrolled at the University of Wolverhampton, participated in this project. Academic performance was significantly associated with factors such as test anxiety, academic competence and time management skills. A high proportion of the study population indicated low academic performance due to perceived course load and amount of study material assigned for each examination. A positive relationship was observed between social and family sources of anxiety and academic performance and stressors. This study also demonstrated that demographic variables, such as family history of anxiety and different stages may have positive or negative effect on academic performance. This study revealed the high level of academic anxiety among the MPharm undergraduates study sample and identified some influential sources which need to be addressed to improve students’ experience. It is important to develop strategies to facilitate students coping strategies and skills with academic life in order to improve future performance.
  • Interplay between Contract and Public law: Implications for Major Construction Contracts and Transparency

    Mante, Joseph; Ndekugri, Issaka E. (Sweet and Maxwell, 2017-02-17)
    The relationship between infrastructure project owners and their contractors is generally governed by contract law. However, where the project owner is a State, there are often additional requirements from public law to be complied with. The challenges posed by the interplay between public law and private contractual relationships in such context have been highlighted by litigation concerning the effect of a constitutional requirement that any international business and economic transaction to which the Government of Ghana (GoG) is a party is not to become operational without parliamentary approval. Through analysis of five decisions of the Supreme Court of Ghana on the interpretation of this constitutional provision, this piece highlights the devastating consequences that inattention to public law could have on parties who contract with the GoG and its agencies. It also examines the extent to which the judicial interpretation of the constitutional requirement really furthers the interests of transparency and openness that it was intended to promote.
  • Genomic epidemiology of clinical Campylobacter spp. at a single health trust site

    Dunn, S.J.; Pascoe, B.; Turton, J.; Fleming, V.; Diggle, M.; Sheppard, S.K.; McNally, A.; Manning, G. (2018-10-11)
    Campylobacter is the leading cause of bacterial enteritis in the developed world, and infections with the organism are largely sporadic in nature. Links between sporadic cases have not been established, with the majority of infections thought to be caused by genetically distinct isolates. Using a read-mapping approach, 158 clinical isolates collected during 2014 from the greater Nottinghamshire area were analysed to assess the local population structure and investigate potential case linkages between sporadic cases of campylobacteriosis. Four instances (2.5 %) of case linkage were observed across the dataset. This study demonstrates that case linkage does occur between sporadic Campylobacter infections, and provides evidence that a dual multi-locus sequence typing/within-lineage single nucleotide polymorphism typing approach to Campylobacter genomic epidemiology provides a benefit to public-health investigations.
  • Impacts of rising temperature, carbon dioxide concentration and sea level on wheat production in North Nile delta

    Kheir, A.; El Baroudy, A.A.; Aiad, M.A.; Zoghdan, M.G.; Abd El-Aziz, M.A.; Ali, M.G.M.; Fullen, M.A. (Elsevier B.V, 2018-10-16)
    Climate change poses a serious threat to arid and low elevation coastal zones. Kafrelsheikh governorate, as a large agricultural and coastal region on the Egyptian North Nile Delta, is one of the most vulnerable areas to higher temperature and global sea level rise. Two DSSAT wheat models (CERES and N-Wheat) were calibrated using a local cultivar (Misr3) grown under irrigated conditions in Egypt. Experimental data of two successive growing seasons during 2014/2015 and 2015/2016 were used for calibration using different treatments of irrigation, planting dates and fertilization. Both models simulated the phenology and wheat yield well, with root mean square deviation of b10%, and d-index N 0.80. Climate change sensitivity analysis showed that rising temperature by 1 °C to 4 °C decreased wheat yield by 17.6%. However, elevated atmospheric CO2 concentrations increased yield and could overtake some of the negative temperature responses. Sea level rise by 2.0 m will reduce the extent of agricultural land on the North Nile Delta of Egypt by ~60% creating an additional challenge to wheat production in this region.
  • Design of Delayed Fractional State Variable Filter for Parameter Estimation of Fractional Nonlinear Models

    Alla, Walid; Zajic, Ivan; Uddin, Kotub; Shen, Zhonghua; Marco, James; Burnham, Keith J. (Springer, 2018-08-17)
    This paper presents a novel direct parameter estimation method for continuous-time fractional nonlinear models. This is achieved by adapting a filter-based approach that uses the delayed fractional state variable filter for estimating the nonlinear model parameters directly from the measured sampled input–output data. A class of fractional nonlinear ordinary differential equation models is considered, where the nonlinear terms are linear with respect to the parameters. The nonlinear model equations are reformulated such that it allows a linear estimator to be used for estimating the model parameters. The required fractional time derivatives of measured input–output data are computed by a proposed delayed fractional state variable filter. The filter comprises of a cascade of all-pass filters and a fractional Butterworth filter, which forms the core part of the proposed parameter estimation method. The presented approaches for designing the fractional Butterworth filter are the so-called, square root base and compartmental fractional Butterworth design. According to the results, the parameters of the fractional-order nonlinear ordinary differential model converge to the true values and the estimator performs efficiently for the output error noise structure.
  • Child and young person development: biological, environmental and interpersonal influences

    Bennett, Kay; Brown, Zeta; Edwards, Tracey (Routledge, 2017-07-27)
  • Bimodal responses of cells to trace elements: insights into their mechanism of action using a biospectroscopy approach

    Llabjania, Valmira; Hoti, Valmira; Pouran, Hamid M.; Martin, Francis L.; Zhang, Hao (Elsevier, 2014-05-22)
    Understanding how organisms respond to trace elements is important because some are essential for normal bodily homeostasis, but can additionally be toxic at high concentrations. The inflection point for many of these elements is unknown and requires sensitive techniques capable of detecting subtle cellular changes as well as cytotoxic alterations. In this study, we treated human cells with arsenic (As), copper or selenium (Se) in a dose–response manner and used attenuated total reflection Fourier-transform infrared (ATR-FTIR) microspectroscopy combined with computational analysis to examine cellular alterations. Cell cultures were treated with Asv, Cu2+ or Seiv at concentrations ranging from 0.001 mg L−1 to 1000 mg L−1 and their effects were spectrochemically determined. Results show that Asv and Cu2+ induce bimodal dose–response effects on cells; this is in line with hormesis-driven responses. Lipids and proteins seem to be the main cell targets for all the elements tested; however, each compound produced a unique fingerprint of effect. Spectral biomarkers indicate that all test agents generate reactive oxygen species (ROS), which could either stimulate repair mechanisms or induce damage in cells.
  • Cathepsin B-Sensitive and Biocompatible Dendritic polyHPMA-Gemcitabine Prodrug-Based Nanoscale System Markedly Enhances the Antitumor Activity

    Dai, Yan; Ma, Xuelei; Zhang, Yanhong; Chen, Kai; Tang, James Zhenggui; Gong, Qiyong; Luo, Kui (The Royal Society of Chemistry, 2018-09)
    To improve therapeutic indexes of gemcitabine (GEM), a stimuli-responsive dendritic polyHPMA copolymer conjugated with gemcitabine (Dendritic polyHPMA-GEM) prodrug was designed and synthesized via one-pot synthesis of RAFT polymerization. The prodrug with dendritic architectures is able to aggregate and form stable nanoscale system with a size of 46 nm. The dendritic prodrug with high molecular weight (HMW) of 168 kDa can biodegrade to low molecular weight (LMW, 29 kDa) segments for excretion. The prodrug demonstrates enzyme-responsive drug release features, and over 95% GEM was released from the carrier with the Cathepsin B within 3 h. The cellular mechanism of the dendritic prodrug was studied, suggesting the cytotoxicity is associated with the cell uptake and cell apoptosis. The prodrug shows good hemocompatibility and in vivo biosafety. Of interest, the dendritic polymer prodrug displays high accumulation within tumors, and markedly improves the in vivo antitumor activity against 4T1 murine breast cancer model compared to the free GEM. These in vivo antitumor activities are characterized as with markedly suppressed tumor volumes, indicating as the much higher tumor growth inhibition (TGI 83%) than that in GEM treatment (TGI, 36%), moreover some tumors are eliminated. The tumor xenograft immunohistochemistry study clearly indicates that the tumor apoptosis is through antiangiogenic effects. These results suggest that the stimuli-responsive dendritic polymer-gemcitabine has great potential as an efficient anticancer agent
  • Coating a polystyrene well-plate surface with synthetic hematite, goethite and aluminium hydroxide for cell mineral adhesion studies in a controlled environment

    Pouran, Hamid M.; Banwart, Steve A.; Romero-Gonzalez, Maria (Elsevier, 2014-01)
    Iron and aluminium oxides are available in many climatic regions and play a vital role in many environmental processes, including the interactions of microorganisms in contaminated soils and groundwater with their ambient environment. Indigenous microorganisms in contaminated environments often have the ability to degrade or transform those contaminants, a concept that supports an in situ remediation approach and uses natural microbial populations in order to bio-remediate polluted sites. These metal oxides have a relatively high pH-dependent surface charge, which makes them good candidates for studying mineral–bacterial adhesion. Given the importance of understanding the reactions that occur at metal oxide and bacterial cell interfaces and to investigate this phenomenon further under well-characterized conditions, some of the most common iron and aluminium oxides; hematite, goethite and aluminium hydroxide, were synthesized and characterized and a coating method was developed to coat polystyrene well-plates as a surface exposable to bacterial adhesion with these minerals (non-treated polystyrene-12 well-plates which are used for cell cultures). The coating process was designed in a way that resembles naturally coated surfaces in aquifers. Hematite, Fe2O3, was synthesized from acidic FeCl3 solution, while goethite, FeOOH, and aluminium hydroxide, Al(OH)3, were prepared from an alkaline solution of Fe(NO3)3 and Al(NO3)3. They were further characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), potentiometric titration and contact angle measurements. Characterization results show that the pure phases of hematite, goethite and aluminium hydroxides are formed with a point of zero charge (PZC) of 7.5, 8.5 and 8.9, respectively. The coating process was based on the direct deposition of mineral particles from an aqueous suspension by evaporation. Then, altered polystyrene surface properties were analyzed using X-ray photoelectron spectroscopy (XPS), attenuated total reflection-Fourier transform infrared (ATR-IR), water drop contact angle measurements and vertical scanning interferometry (VSI). The surface analysis tests prove that the coated polystyrene surface has physicochemical properties that are similar to the reference synthetic hematite, goethite and aluminium hydroxide minerals. These prepared and well-characterized mineral well-plates are similar to naturally occurring surfaces in aquifers and enable us to study the different steps of bacterial adhesion and biofilm formation on these metal oxides under laboratory-controlled conditions.
  • Time delay and cost overrun of road over bridge (ROB) construction projects in India

    Venkateswaran, Chandrasekaran Balaji; Murugasan, Rajiah (Penerbit Universiti Sains Malaysia, 2017-11-24)
    This paper aims at studying the factors that contribute to time delay and cost overrun of Road over Bridge (ROB) projects in India. Data for the research study were collected from 62 respondents, including owners, contractors, and consultants of ROB projects. The literature survey and the questionnaire survey helped in identifying 29 factors. The topmost factors were ranked based on the frequency of occurrences. The correlation among owners, contractors, and consultants on ranking of factors was derived by Spearman rank correlation. Factor analysis was used to classify the factors into groups and identify the key groups responsible for time delay and cost overrun of projects. This study will help all stakeholders of ROB projects in India to understand the factors and thereby reduce time delay and cost overrun as well as expedite their completion.
  • Optimistic bias in physical activity: when exercise flows into addiction

    Riva, Silvia; Masiero, Marianna; Mazzocco, Ketti; Pravettoni, Gabriella (Kowsarmedical, 2018-03)
    Background: Traditionally, psychologists have been involved in identifying the minimum amount of physical activity needed to be healthy. Latest research has changed direction and is starting to shed some light on a new trend characterized by excessive physical activity, especially in young adults. Objectives: This study aimed at examining how an intense physical activity can have detrimental psychological effects and turn into an addiction with possible repercussion on health, especially when individuals continue to have maladaptive behaviors such as smoking and drinking. Patients and Methods: A convenience sample of 158 participants (female = 101; male = 57) was enrolled, with a mean age of 28 years (SD = 6.09). A questionnaire was administered to evaluate both the optimistic bias in smokers and drinkers and the time spent in physical activity. Results: Participants showing smoking and drinking behaviors were categorized according to the extent of performed physical activity. Descriptive analyses revealed that 26% of participants were “inactive”, while 8.30% practiced “intense activity” and 8.30% practiced “extremely intense activity”. People who had 7 to 8 hours of physical activity per week estimated the risk of getting bladder cancer as “much below average” (P = 0.039). Consistent results were found for stroke (P = 0.015). Conclusions: This study aimed at offering an innovative starting point to examine more closely the role of such mechanism in individuals practicing intense and sometimes excessive physical activity. Our results may offer new hints for researchers working in the prevention and education of adolescents and young-adults.
  • Measurement of ZnO nanoparticles using diffusive gradients in thin films: binding and diffusional characteristics

    Pouran, Hamid M.; Martin, Francis L; Zhang, Hao (ACS (American Chemical Society), 2014)
    Rapid growth in finding new applications for manufactured nanomaterials (MNM) has recently been accompanied by awareness about their related adverse toxicological and environmental impacts. Due to their intrinsic nature, measuring available concentrations of MNMs in the environment is a major challenge. This research is a launching point toward filling this gap, as it presents the potential of the well-established diffusive gradients in thin films (DGT) technique to determine MNMs concentrations in situ. Two binding layers commonly used in DGT devices were shown to be able to bind ZnO nanoparticles (ZnO NPs). The use of different types of diffusive layers demonstrated the critical role of their pore size for selective function of the DGT devices. The ZnO NPs can pass through the open pore diffusive layer used in standard DGT devices and be retained by the binding resin layer. However, the diffusion of ZnO NPs can be prevented when a 1000 MWCO (molecular weight cut off) dialysis membrane is placed in the front of the diffusive gel layer. A combination of two or more DGT devices with known diffusive layer properties should enable deduction of concentrations of available ZnO NPs in the environment. Unlike metal ions, determining diffusion coefficient values for ZnO NPs is challenging and greatly affected by shape, morphology, and solution-induced changes of the particles. Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) demonstrated that retention of ZnO NPs by Chelex and Metsorb binding layers occurs through chemisorption. The superior uptake kinetic for Chelex indicates that it is a better candidate for further development of DGT devices to measure ZnO NPs. These initial results are promising and important for further developing the DGT technique to measure available concentrations of manufactured nanomaterials in the different environmental media (waters, soils, and sediments). Further experiments investigating the effects of pH, ionic strength, and solution chemistry on the performance of DGT for measuring MNM concentrations are needed.

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