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"Dominica"
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Playing with languages
Over several generations villagers of Dominica have been shifting from Patwa, an Afro-French creole, to English, the official language. Despite government efforts at Patwa revitalization and cultural heritage tourism, rural caregivers and teachers prohibit children from speaking Patwa in their presence. Drawing on detailed ethnographic fieldwork and analysis of video-recorded social interaction in naturalistic home, school, village and urban settings, the study explores this paradox and examines the role of children and their social worlds. It offers much-needed insights into the study of language socialization, language shift and Caribbean children's agency and social lives, contributing to the burgeoning interdisciplinary study of children's cultures. Further, it demonstrates the critical role played by children in the transmission and transformation of linguistic practices, which ultimately may determine the fate of a language.
eBook
Dominica : the Bradt travel guide
Author Paul Crask has lived on Dominica for over ten years and his guide is rich in detail, both in terms of background and practical information for explorers, eco-tourists and culture vultures. No other book has such personal, on-the-ground information as this. For this third edition, there are detailed descriptions of more hikes and natural attractions, including the iconic Boiling Lake; more selective and in-depth accommodation and dining listings; plus extensive guide and tour operator listings. The guide also includes the 14-segment, 200km Wai'tukubuli National Trail, the only one of its kind in the eastern Caribbean. Tiny but perfectly-formed Dominica is one of the most naturally dramatic islands of the Lesser Antilles. This beautiful island with its verdant mountains, lush valleys and dense tropical rainforests is still off the mass-tourism trail. However, cruise ships, hikers, scuba divers and nature-lovers are starting to discover this gorgeous 'Nature Island of the Caribbean'.
Book
Productivity performance of peach trees, insecticidal and antibacterial bioactivities of leaf extracts as affected by nanofertilizers foliar application
The current study was performed on eight years old peach (
Prunus persica
L. Batsch) trees cv. Florida prince to study the influence of spraying of commercial nano fertilizer on vegetative growth, pollen grain viability, yield, and fruit quality of the \"Florida prince\" peach cultivar. Furthermore, extracts from the nanofertilizer treated leaves were studied for their bioactivity as insecticidal or bactericidal activities against some stored grain insects and plant bacterial pathogens. Seventy uniform peach trees were sprayed three time as follow: before flowering; during full bloom, and one month later in addition using the water as a control. Commercial silver particales (Ag NPs) at 10, 12.5, and 15 mL/L and zinc particales (Zn NPs) at 2.5, 5 and 7.5 mL/L as recommended level in a randomized complete block design in ten replicates/trees. Spraying Ag NP at 15 mL/L increased shoot diameter, leaf area, total chlorophyll, flower percentage, fruit yield and fruit physical and chemical characteristics, followed by Ag NPs at 12.5 mL/L and Zn NPs at 7.5 mL/L. Moreover, Zn and Ag NPs caused a highly significant effect on pollen viability. Different type of pollen aberrations were detected by Zn NPs treatment. The commercial Ag NPs showed a high increase in pollen viability without any aberrations. The Ag NPs significantly increased the pollen size, and the spores also increased and separated in different localities, searching about the egg for pollination and fertilization. Peach leaves extract was examined for their insecticidal activity against rice weevil (
Sitophilus oryzea
L.) and the lesser grain borer (
Rhyzopertha dominica,
Fabricius) by fumigation method. The antibacterial activity of all treatments was also performed against molecularly identified bacteria. Ag NPs treated leaves extract at concentration 3000 µg/mL were moderate sufficient to inhibit all the bacterial isolates with inhibition zone (IZ) ranged 6–8.67 mm with high efficiency of acetone extracts from leaves treated with Ag NPs compared with Zn NPs
.
Also,
S. oryzae
was more susceptible to acetone extracts from leaves treated with both nanomaterials than
R. dominica.
Journal Article
Landscape, land-change & well-being in the Lesser Antilles : case studies from the coastal villages of St. Kitts and the Kalinago Territory, Dominica
This research investigates the changing landscape and land use in two case studies of the coastal villages of St. Kitts and the Kalinago Territory of Dominica. By integrating human and ecological aspects of agrarian landscapes, this research analyzes how land degradation or land change impacts cultural ecosystem services, that ultimately disrupts community wellbeing. First, as a primary goal, the research focus is established together with local communities or stakeholders, identifying both direct and indirect causes of landscape change. Second, by using a variety of qualitative and quantitative methods, but grounded in local participation, the research indicates that landscape change never happens in a vacuum but rather, it is always a part of a larger socio-political context and historical background that must be considered. In both case studies, there remains emphasis on the tangible, as results not only lead to new directions in landscape research but also deliverables used by community stakeholders for continued land sustainability.
Book
Efficacy Assessment of Biosynthesized Copper Oxide Nanoparticles (CuO-NPs) on Stored Grain Insects and Their Impacts on Morphological and Physiological Traits of Wheat (Triticum aestivum L.) Plant
Herein, CuO-NPs were fabricated by harnessing metabolites of Aspergillus niger strain (G3-1) and characterized using UV–vis spectroscopy, XRD, TEM, SEM-EDX, FT-IR, and XPS. Spherical, crystallographic CuO-NPs were synthesized in sizes ranging from 14.0 to 47.4 nm, as indicated by TEM and XRD. EDX and XPS confirmed the presence of Cu and O with weight percentages of 62.96% and 22.93%, respectively, at varied bending energies. FT-IR spectra identified functional groups of metabolites that could act as reducing, capping, and stabilizing agents to the CuO-NPs. The insecticidal activity of CuO-NPs against wheat grain insects Sitophilus granarius and Rhyzopertha dominica was dose- and time-dependent. The mortality percentages due to NP treatment were 55–94.4% (S. granarius) and 70–90% (R. dominica). A botanical experiment was done in a randomized block design. Low CuO-NP concentration (50 ppm) caused significant increases in growth characteristics (shoot and root length, fresh and dry weight of shoot and root, and leaves number), photosynthetic pigments (total chlorophylls and carotenoids), and antioxidant enzymes of wheat plants. There was no significant change in carbohydrate or protein content. The use of CuO-NPs is a promising tool to control grain insects and enhance wheat growth performance.
Journal Article
Deep Machine Learning Techniques for the Detection and Classification of Sperm Whale Bioacoustics
We implemented Machine Learning (ML) techniques to advance the study of sperm whale (
Physeter macrocephalus
) bioacoustics. This entailed employing Convolutional Neural Networks (CNNs) to construct an echolocation click detector designed to classify spectrograms generated from sperm whale acoustic data according to the presence or absence of a click. The click detector achieved 99.5% accuracy in classifying 650 spectrograms. The successful application of CNNs to clicks reveals the potential of future studies to train CNN-based architectures to extract finer-scale details from cetacean spectrograms. Long short-term memory and gated recurrent unit recurrent neural networks were trained to perform classification tasks, including (1) “coda type classification” where we obtained 97.5% accuracy in categorizing 23 coda types from a Dominica dataset containing 8,719 codas and 93.6% accuracy in categorizing 43 coda types from an Eastern Tropical Pacific (ETP) dataset with 16,995 codas; (2) “vocal clan classification” where we obtained 95.3% accuracy for two clan classes from Dominica and 93.1% for four ETP clan types; and (3) “individual whale identification” where we obtained 99.4% accuracy using two Dominica sperm whales. These results demonstrate the feasibility of applying ML to sperm whale bioacoustics and establish the validity of constructing neural networks to learn meaningful representations of whale vocalizations.
Journal Article
Enhanced-Efficacy Iranian Diatomaceous Earth for Controlling Two Stored-Product Insect Pests
The present study was conducted to evaluate the insecticidal activity of three diatomaceous earth (DE) products, SilicoSec (Biofa GmbH, Munsingen, Germany), Protect-It (Hedley Technologies Inc., Canada), and Mamaghan. The silica aerogel was mixed to enhance the efficacy of Mamaghan DE with 10, 15, and 20% rates. The DE products were applied at treatment rates of 100, 200, and 400 ppm against adults of Tribolium confusum Jacquelin du Val. (Coleoptera: Tenebrionidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae). In the second experiment, 0.1 and 0.5% deltamethrin was added to Mamaghan DE–10% silica aerogel to enhance the activity of the DE. Adult mortality was recorded 2, 5, 7, 10, and 14 d after exposure. Parental adults were removed after 14-d exposure time and progeny developed was evaluated after 65 d. Mamaghan–15 and 20% silica aerogel caused the highest mortality (>97%) against T. confusum after 10 d of exposure at the highest dose of 400 ppm which exceeded to 100% mortality after 14 d. However, the toxicity of Mamaghan DE against R. dominica was lower than that of the two commercial formulations at all dose rates. The presence of 0.1% deltamethrin increased the insecticidal activity of Mamaghan DE and significantly suppressed progeny production of both species. Even at the lowest dose of Mamaghan–10% + 0.1% deltamethrin, progeny production of both species was very low (four or less individuals per vial). However, no progeny was recorded in Mamaghan–10% + 0.5% deltamethrin. Thus, adding low rates of silica aerogel and deltamethrin considerably enhanced the efficacy of Mamaghan DE in controlling T. confusum and R. dominica.
Journal Article
A core metabolic enzyme mediates resistance to phosphine gas
Phosphine is a small redox-active gas that is used to protect global grain reserves, which are threatened by the emergence of phosphine resistance in pest insects. We find that polymorphisms responsible for genetic resistance cluster around the redox-active catalytic disulfide or the dimerization interface of dihydrolipoamide dehydrogenase (DLD) in insects (Rhyzopertha dominica and Tribolium castaneum) and nematodes (Caenorhabditis elegans). DLD is a core metabolic enzyme representing a new class of resistance factor for a redox-active metabolic toxin. It participates in four key steps of core metabolism, and metabolite profiles indicate that phosphine exposure in mutant and wild-type animals affects these steps differently. Mutation of DLD in C. elegans increases arsenite sensitivity. This specific vulnerability may be exploited to control phosphine-resistant insects and safeguard food security.
Journal Article
A comparative study of monoterpenoids and phenylpropanoids from essential oils against stored grain insects: acute toxins or feeding deterrents
The relationship between the acute toxicity and feeding deterrent activity of ten compounds occurring commonly in essential oils was explored in order to determine whether they are acute toxins or antifeedants against stored-grain pests. Simultaneously, the objective was also to demonstrate the comparative efficacy against three post-harvest stored-grain pests. Thymol, carvacrol, eugenol and
trans
-anethole were specifically toxic, and linalool was a generalist feeding deterrent against all three species studied. Thymol was most toxic to
Tribolium castaneum
and
Rhyzopertha dominica
compared to carvacrol and eugenol but was least toxic to
Sitophilus oryzae
. Similarly, linalool deterred feeding of
S. oryzae
(FI
50
= 0.025 mg/g of the wafer diet),
T. castaneum
(FI
50
= 0.207 mg/g of the wafer diet) and
R. dominica
(FI
50
= 0.482 mg/g of the wafer diet) at different concentrations;
R. dominica
beetles required about 20 times the concentration to deter feeding compared to
S. oryzae
and more than twice compared to
T. castaneum
. Comparison of toxicity and deterrent activity with respective artificial blends as binary mixtures revealed that synergism was not a generalized phenomenon, and the variations were both species as well as blend specific. Individual compound efficacy correlations were not ascertained, which suggests that artificial blends could be prepared to obtain potential mixtures for substantial control of stored-grain insect pests. The present study also implies that the compounds are mostly acute toxins, and whatever inhibition in feeding was obtained could be due to physiological toxicity rather than any interaction with gustatory receptors.
Journal Article