3,214 research outputs found
The Rearing and Biology of the Desert Beetle, Microdera punctipennis, Under Laboratory Conditions
Microdera punctipennis Kasz (Coleoptera: Tenebrionidae) is a unique species that lives in the desert region of Central Asia and has adopted a nocturnal habit to survive the desert environment. Female adults are larger in size than male adults. The female/male ratio was 1.04:1. A rearing method using reused plastic bottles was used. The rearing conditions were 30 ± 0.5°C, 30 ± 6% relative humidity (RH), and 16:8 L:D photoperiod. Cabbage was provided as food. Cannibalism was avoided by rearing one larva in a bottle. A complete life cycle was obtained under these conditions. The viability of eggs, larvae, prepupae, pupae, and teneral adults was 93.54%, 83.71%, 84.76%, 87.64%, and 93.59%, respectively. Embryogenesis took 7.35 days on average. The larval duration in each instar was 2.25 days. The mean duration of the larvae, prepupae, pupae, and teneral adult was 49.27, 7.05, 9.95, and 10.12 days, respectively. The coloration of each developmental stage gradually changed from creamy white to light brownish or black. Females commenced oviposition when their body color became black. On average, each female produced 568 eggs
Different atmospheric moisture divergence responses to extreme and moderate El Niños
On seasonal and inter-annual time scales, vertically integrated moisture divergence provides a useful measure of the tropical atmospheric hydrological cycle. It reflects the combined dynamical and thermodynamical effects, and is not subject to the limitations that afflict observations of evaporation minus precipitation. An empirical orthogonal function (EOF) analysis of the tropical Pacific moisture divergence fields calculated from the ERA-Interim reanalysis reveals the dominant effects of the El Niño-Southern Oscillation (ENSO) on inter-annual time scales. Two EOFs are necessary to capture the ENSO signature, and regression relationships between their Principal Components and indices of equatorial Pacific sea surface temperature (SST) demonstrate that the transition from strong La Niña through to extreme El Niño events is not a linear one. The largest deviation from linearity is for the strongest El Niños, and we interpret that this arises at least partly because the EOF analysis cannot easily separate different patterns of responses that are not orthogonal to each other. To overcome the orthogonality constraints, a self-organizing map (SOM) analysis of the same moisture divergence fields was performed. The SOM analysis captures the range of responses to ENSO, including the distinction between the moderate and strong El Niños identified by the EOF analysis. The work demonstrates the potential for the application of SOM to large scale climatic analysis, by virtue of its easier interpretation, relaxation of orthogonality constraints and its versatility for serving as an alternative classification method. Both the EOF and SOM analyses suggest a classification of “moderate” and “extreme” El Niños by their differences in the magnitudes of the hydrological cycle responses, spatial patterns and evolutionary paths. Classification from the moisture divergence point of view shows consistency with results based on other physical variables such as SST
Comparaison de deux techniques de replantation cacaoyère sur antécédents culturaux non-forestiers en Côte d’Ivoire
Le verger de cacaoyers de la Côte d’Ivoire, premier producteur mondial de cacao, est vieillissant et doit être régénéré pour assurer une production durable de cacao. Mais, les réserves de forêt utilisées autrefois pour l’extension des plantations sont épuisées. Les terres cultivables disponibles sont les jachères et les cacaoyères dégradées. Malheureusement, la plupart des tentatives de plantation sur ces antécédents culturaux dégradés échouent. En vue de proposer aux producteurs des itinéraires techniques adaptés, deux techniques de replantation ont été comparées sur 40 parcelles replantées dont 20 après des vieux cacaoyers âgés de plus de 30 ans avec moins de 700 arbres ha-1 et 20 autres après des jachères de durée inférieure à 10 ans. Ces parcelles ont été installées entre 2004 et 2006 dans 10 régions productrices de cacao. Les résultats ont montré que la replantation sous vieux cacaoyers est plus efficace. L’efficacité de cette technique est liée à la fertilité des sols relativement meilleure et au niveau d’enherbement plus faible sous les vieux cacaoyers par rapport aux jachères. Il est cependant nécessaire de bien gérer l’ombrage des vieux cacaoyers, en effectuant des éclaircies avant 6 et 24 mois après la mise en place des jeunes cacaoyers.Mots Clés: Cacao, itinéraires techniques, jachère, régénérationEnglish AbstractCocoa farms of Côte d’Ivoire, the world’s largest cocoa producer, are getting older and must be regenerated for sustainable cocoa production. However, forest reserves formerly used for the expansion of plantations are finished. Available cultivable land parcels are fallows with poor soil and degraded cocoa farms. Unfortunately, most attempts of replanting on these poor lands fail. In order to provide producers with appropriate replanting techniques, two replanting techniques were compared on a 40 replanted plots, including 20 plots after more than 30 years-old cocoa farms with less than 700 trees ha-1 and 20 other plots after fallows of less than 10 years. These plots were installed between 2004 and 2006 in 10 cocoa producing areas. Replanting under the old cocoa trees is more effective. The effectiveness of this practice is related to the relatively better soil fertility and lower level of the weeds proliferation under the old cocoa trees as compared to the fallows. It is, however, necessary to reduce the shade of the old cocoa trees before 6 and 24 months after the establishment of the young cocoa trees.Keywords: Cocoa, fallow, previous land, regeneratio
Luminescent properties and reduced dimensional behavior of hydrothermally prepared Y <inf>2</inf>SiO <inf>5</inf>: Ce nanophosphors
Hydrothermally prepared nanophosphor Y2 Si O5: Ce crystallizes in the P 21 c structure, rather than the B2b structure observed in bulk material. Relative to bulk powder, nanophosphors of particle size ∼25-100 nm diameter exhibit redshifts of the photoluminescence excitation and emission spectra, reduced self absorption, enhanced light output, and medium-dependent radiative lifetime. Photoluminescence data are consistent with reduced symmetry of the P 21 c structure and are not necessarily related to reduced dimensionality of the nanophosphor. In contrast, medium-dependent lifetime and enhanced light output are attributed to nanoscale behavior. Perturbation of the Ce ion electric field is responsible for the variable lifetime. © 2006 American Institute of Physics
Regular mass screening for SARS-CoV-2 infection in care homes already affected by COVID-19 outbreaks: Implications of false positive test results
Prevalence and risk factors for esophageal squamous cell cancer and precursor lesions in Anyang, China: a population-based endoscopic survey
BACKGROUND: The etiology of esophageal squamous cell cancer (ESCC) in high prevalence regions of China remains unclear. METHODS: Endoscopic biopsies were conducted among 7381 inhabitants aged from 25 to 65 of Anyang, China. RESULTS: In this study, 2.57, 0.20 and 0.16% of the participants had mild, moderate and severe squamous dysplasia, respectively; 0.19 and 0.08% showed squamous carcinoma in situ and invasive ESCC. Using deep well (depth >100 meters) as water source (odds ratio = 0.72, 95% confidence interval: 0.54-0.96) was negatively associated with ESCC and its precursors, whereas tobacco and alcohol use were not significantly associated with ESCC. CONCLUSIONS: Water source and other factors in this region need further evaluation by longitudinal studies. British Journal of Cancer (2010) 103, 1085-1088. doi:10.1038/sj.bjc.6605843 www.bjcancer.com Published online 10 August 2010 (C) 2010 Cancer Research UKOncologySCI(E)PubMed19ARTICLE71085-108810
Integrated production and distribution scheduling problems related with fixed delivery departure dates and number of late orders
Aplastic anemia associated with interferon alpha 2a in a patient with chronic hepatitis C virus infection: a case report
<p>Abstract</p> <p>Introduction</p> <p>Hepatitis-associated aplastic anemia is a common syndrome in patients with bone marrow failure. However, hepatitis-associated aplastic anemia is an immune-mediated disease that does not appear to be caused by any of the known hepatitis viruses including hepatitis C virus. In addition, to the best of our knowledge there are no reported cases of patients with chronic hepatitis C virus infection developing aplastic anemia associated with pegylated interferon alpha 2a treatment.</p> <p>Case presentation</p> <p>We report the case of a 46-year-old Greek man who developed severe aplastic anemia during treatment with pegylated interferon alpha 2a for chronic hepatitis C virus infection. He presented with generalized purpura and bruising, as well as pallor of the skin and mucous membranes. His blood tests showed pancytopenia. He underwent allogeneic bone marrow transplantation after completing two courses of immunosuppressive therapy with antithymocyte globulin and cyclosporin A.</p> <p>Conclusions</p> <p>The combination of a specific environmental precipitant represented by the hepatitis C virus infection, an altered metabolic detoxification pathway due to treatment with pegylated interferon alpha 2a and a facilitating genetic background such as polymorphism in metabolic detoxification pathways and specific human leukocyte antigen genes possibly conspired synergistically in the development of aplastic anemia in this patient. Our case clearly shows that the causative role of pegylated interferon alpha 2a in the development of aplastic anemia must not be ignored.</p
Anisotropic Charge Distribution and Anisotropic van der Waals Radius Leading to Intriguing Anisotropic Noncovalent Interactions
Although group (IV-VII) nonmetallic elements do not favor interacting with anionic species, there are counterexamples including the halogen bond. Such binding is known to be related to the charge deficiency because of the adjacent atom's electron withdrawing effect, which creates s/p-holes at the bond-ends. However, a completely opposite behavior is exhibited by N-2 and O-2, which have electrostatically positive/negative character around cylindrical-bond-surface/bond-ends. Inspired by this, here we elucidate the unusual features and origin of the anisotropic noncovalent interactions in the ground and excited states of the 2nd and 3rd row elements belonging to groups IV-VII. The anisotropy in charge distributions and van der Waals radii of atoms in such molecular systems are scrutinized. This provides an understanding of their unusual molecular configuration, binding and recognition modes involved in new types of molecular assembling and engineering. This work would lead to the design of intriguing molecular systems exploiting anisotropic noncovalent interactions.open
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