Photoacoustic Technique in the Study of Photosynthesis in Aquatic Lirium (Eichhornia Crassipes)

2012 ◽  
Vol 1480 ◽  
Author(s):  
A. Calderón ◽  
A. Cardona ◽  
G. Juárez Gracia ◽  
E. Marín ◽  
Cesar Mora
Keyword(s):  
Optical Absorption ◽  
Eichhornia Crassipes ◽  
Aquatic Plant ◽  
Photoacoustic Technique ◽  
Optical Absorption Spectra ◽  
Tropical Regions ◽  
The World ◽  
Before And After ◽  
Bodies Of Water ◽  
First Time

ABSTRACTWe report, for the first time, the application of the photoacoustic spectroscopy for monitoring the optical absorption spectra in aquatic lirium (Eichhornia Crassipes), before and after it was exposed to ultrasonic irradiations. We obtained a decrease in the amplitude of the bands of the chlorophylls a and b for the irradiated samples with ultrasound of 17 kHz and 1.5 mW/cm2 of power density, and therefore, damage in the centers producing the photosynthesis, due to the irradiation. These results show the utility of the ultrasonic irradiation, as well as, of the photosynthesis monitoring by means of the photoacoustic technique, for the elaboration and establishment of methodologies in the control of this aquatic plant, whose propagation causes many consequences extremely unfavorable for the environment, as well as for the diverse human activities that are developed in the bodies of water in the tropical and sub-tropical regions of the world.

scholarly journals Remarkable Species Diversity of the Leafhopper Genus Xestocephalus (Hemiptera: Cicadellidae: Aphrodinae) in Thailand

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 514
Author(s):  
Zonglei Liang ◽  
Christopher H. Dietrich ◽  
Wu Dai
Keyword(s):  
New Species ◽  
Species Diversity ◽  
Single Species ◽  
Comparative Morphology ◽  
Malaise Trap ◽  
Field Sampling ◽  
Tropical Regions ◽  
Trap Field ◽  
The World ◽  
First Time

Xestocephalus Van Duzee is among the most common and widespread genera of Cicadellidae in the temperate and tropical regions of the world. In the present study, 205 specimens of the genus Xestocephalus were collected in Thailand, whereas only a single species of the genus was recorded previously using Malaise trap field sampling, studied by comparative morphology. Seventeen species were recognized, including twelve new species: X. binarius sp. nov., X. chrysanthemum sp. nov., X. cowboyocreus sp. nov., X. densprint sp. nov., X. dimiprocessus sp. nov., X. exproiecturus sp. nov., X. gracilus sp. nov., X. limpidissimus sp. nov., X. malleus sp. nov., X. nonattribus sp. nov., X. recipinams sp. nov., and X. tenusis Liang sp. nov. Four species were recorded in Thailand for the first time: Xestocephalus abyssinicus Heller and Linnavuori, Xestocephalus asper Linnavuori, Xestocephalus ishidae Matsumura, and Xestocephalus toroensis Matsumura. Detailed morphological descriptions of all 17 species are given; photographs of external habitus and male genitalia of the species from Thailand are provided. A checklist of species of the genus is also given, and a key to all Thailand Xestocephalus species is also provided.

Eichhornia crassipes (water hyacinth).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez
Keyword(s):  
Biological Control ◽  
Water Hyacinth ◽  
Management Strategy ◽  
Eichhornia Crassipes ◽  
Aquatic Plant ◽  
Integrated Management ◽  
Rice Paddy ◽  
The World ◽  
Rice Paddy Fields

Abstract E. crassipes, a native of South America, is a major freshwater weed in most of the frost-free regions of the world and is generally regarded as the most troublesome aquatic plant (Holm et al., 1997). It has been widely planted as a water ornamental around the world because of its striking flowers. Wherever it has encountered suitable environmental conditions it has spread with phenomenal rapidity to form vast monotypic stands in lakes, rivers and rice paddy fields. Then it adversely affects human activities (fishing, water transport) and biodiversity. It is impossible to eradicate, and often only an integrated management strategy, inclusive of biological control, can provide a long-term solution to this pest.

The Christian Understanding of Time

1951 ◽  
Vol 4 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Emil Brunner
Keyword(s):  
Time Series ◽  
Jesus Christ ◽  
Epistle To The Hebrews ◽  
The World ◽  
Before And After ◽  
Christian Understanding ◽  
The Creation ◽  
First Time ◽  
Point Of Departure ◽  
Christian Message

The Christian understanding of time is characterised by an event which is the very centre of the Christian message, and of which it is said that it happened once and for all. This ephapax is evidently an essential part of the theology of St. Paul and of the Epistle to the Hebrews. The Christian conceives of time like everything else from this centre, i.e. from Jesus Christ, and therefore it is from this centre that our reflection upon the essence of time has to start. This must be stated explicitly because another point of departure has been suggested by traditional theology. Certainly it was an act of great intuition on the part of St. Augustine when in his Confessions he dared, for the first time in history, to put forward the idea that the world was neither timeless and eternal, nor created at a certain point in the time-series, but that the world and time were created together. Therefore if the world and time have the same beginning in creation, it becomes meaningless to ask what God did before the creation of the world. The whole schema of before and after, the framework of time, cannot be regarded as existing before creation, but as coming into being with creation, itself a temporal fact.

Nylanderia of the World Part III: Nylanderia in the West Indies

Zootaxa ◽  
2019 ◽  
Vol 4658 (3) ◽  
pp. 401-451 ◽  
Author(s):  
JOHN S. LaPOLLA ◽  
ROBERT J. KALLAL
Keyword(s):  
New Species ◽  
Introduced Species ◽  
West Indies ◽  
The West ◽  
Sem Images ◽  
World Species ◽  
Tropical Regions ◽  
New Synonyms ◽  
The World ◽  
First Time

The diversity of the formicine ant genus Nylanderia is currently underestimated and largely undescribed. This includes the faunas of tropical regions where species richness is typically high. Here, the taxonomy of the West Indian Nylanderia fauna is revised for the first time. Fourteen new species are described, bringing the total number of species known from the region to 22. The new species are: N. bibadia, sp. nov., N. caerula, sp. nov., N. coveri, sp. nov., N. disatra, sp. nov., N. esperanza, sp. nov., N. fuscaspecula, sp. nov., N. lucayana, sp. nov., N. metacista, sp. nov., N. pini, sp. nov., N. semitincta, sp. nov., N. sierra, sp. nov., N. wardi, sp. nov., N. xestonota, sp. nov., and N. zaminyops, sp. nov. There are several introduced species in the region including the globally widespread Old World species N. bourbonica. Other introduced species are N. fulva, N. pubens, N. guatemalensis, and N. steinheili. The following new synonyms are proposed: fulva Mayr 1862 (= fulva cubana Santschi 1930); steinheili Forel 1893 (= steinheili minuta Forel 1893). An identification key is provided for the workers of Nylanderia found in the West Indies. Photomontage images are provided for the worker of each species and when available photomontage and SEM images are provided for males. This work represents another step forward in understanding the diversity of this widespread and commonly encountered ant genus.

scholarly journals Тип оптических переходов на краю фундаментального поглощения кристаллов TlGaSe-=SUB=-2-=/SUB=- и TInS-=SUB=-2-=/SUB=-, подвергнутых γ-облучению

2019 ◽  
Vol 127 (9) ◽  
pp. 420
Author(s):  
Р.М. Сардарлы ◽  
Ф.Т. Салманов ◽  
Н.А. Алиева
Keyword(s):  
Optical Properties ◽  
Radiation Dose ◽  
Optical Absorption ◽  
Gamma Irradiation ◽  
Single Crystals ◽  
Irradiation Dose ◽  
Optical Transitions ◽  
Optical Absorption Spectra ◽  
Interband Transitions ◽  
Before And After

The effect of gamma irradiation on the optical properties of layered TlGaSe2 and TlInS2 crystals in the wavelength range of 400–1,100 nm at 300 K is studied. From the analysis of optical absorption spectra, the energies of direct and indirect optical interband transitions before and after gamma irradiation are determined. It is shown that as the gamma-irradiation dose is accumulated in the range of 0–25 Mrad by TlGaSe2 and TlInS2 single crystals, the energies of direct and indirect allowed optical transitions increase from Egd = 2.06 eV and Egi = 1.90 eV at D = 0 Mrad to Egd = 2.11 eV and Egi = 1.98 eV at D = 25 Mrad for TlGaSe2 and Egd = 2.32 eV crystals and Egi = 2.27 eV at D = 0 Mrad to Egd = 2.35 and Egi = 2.32 eV at D = 25 Mrad for TlInS2 crystals. A decrease in the transmittance at doses from 0 to 5 Mrad and a further increase in the transmittance at the radiation dose D = 25 Mrad are observed.

scholarly journals Mutation density changes in SARS-CoV-2 are related to the pandemic stage but to a lesser extent in the dominant strain with mutations in spike and RdRp

2020 ◽  
Author(s):  
Doğa Eskier ◽  
Aslı Suner ◽  
Gökhan Karakülah ◽  
Yavuz Oktay
Keyword(s):  
Viral Genome ◽  
Time Dependent ◽  
Origin And Evolution ◽  
Gene Level ◽  
The Us ◽  
The World ◽  
Before And After ◽  
Different Characteristics ◽  
First Time ◽  
New Mutations

AbstractSince its emergence in Wuhan, China in late 2019, the origin and evolution of SARS-CoV-2 have been among the most debated issues related to COVID-19. Throughout its spread around the world, the viral genome continued acquiring new mutations and some of them became widespread. Among them, 14408 C>T and 23403 A>G mutations in RdRp and S, respectively, became dominant in Europe and the US, which led to debates regarding their effects on the mutability and transmissibility of the virus. In this study, we aimed to investigate possible differences between time-dependent variation of mutation densities (MDe) of viral strains that carry these two mutations and those that do not. Our analyses at the genome and gene level led to two important findings: First, time-dependent changes in the average MDe of circulating SARS-CoV-2 genomes showed different characteristics before and after the beginning of April, when daily new case numbers started levelling off. Second, this pattern was much delayed or even non-existent for the “mutant” (MT) strain that harbored both 14408 C>T and 23403 A>G mutations. Although these differences were not limited to a few hotspots, it is intriguing that the MDe increase is most evident in two critical genes, S and Orf1ab, which are also the genes that harbor the defining mutations of the MT genotype. The nature of these unexpected relationships warrant further research.

Impact of Cr3+ substitution on the nephelauxetic ratio and Racah parameter of Cr-Mn-Zn nanoferrites

2021 ◽  
Author(s):  
M. Abdo ◽  
M.S. Sadeq
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Tunable Laser ◽  
Ligand Field ◽  
Optical Absorption Spectra ◽  
B Values ◽  
Racah Parameter ◽  
Low Field ◽  
Optical Applications ◽  
First Time

Abstract For the first time, we present the ligand field splitting (10Dq) nephelauxetic ratio (β), Racah parameter (B) and stability of Cr3+ within Mn–Zn nanoferrite which synthesized using the citrate route. These parameters were determined via optical absorption spectra. The obtained bands in the significance range of optical absorption spectra are wide as well as asymmetric; therefore the deconvolution process becomes a necessary task. The values of 10Dq and B have been estimated from the produced bands. The values of 10Dq are observed to increase from 16366.61 to 16447.37 cm-1 whereas, B values are observed to decrease from 829.81 to 760.80 cm-1 with additional Cr3+ substitution. The increasing 10Dq and decreasing B values, evidence for bonds between Cr3+ ions with their environments became a further covalent (less ionic). Moreover, the values of β are observed to decrease for further Cr3+ substitution. This decrease of β produces less stability between Cr3+ and its ligand. Furthermore, Dq/B values declare that Cr3+ centers are in the low-field sites by a slight tendency towards the high-field sites with further Cr/Fe substitution process. Therefore, it was suggested that Cr3+ substituted Mn–Zn nanoferrites are excellent candidates for diverse optical applications such as a tunable laser.

scholarly journals Graphomya Robineau-Desvoidy from Costa Rica: descriptions and first records (Diptera, Muscidae)

2009 ◽  
Vol 69 (3) ◽  
pp. 951-956
Author(s):  
MS. Couri ◽  
B. Marques
Keyword(s):  
Costa Rica ◽  
Neotropical Region ◽  
Male And Female ◽  
Tropical Regions ◽  
The World ◽  
First Time

Graphomya Robineau-Desvoidy (Diptera, Muscidae) occurs in temperate and tropical regions of the world. It is known in the Neotropical Region from fifteen species. The genus is here recorded for the first time from Costa Rica, on the basis of three species: G. auriceps Malloch, 1934; G. mexicana Giglio-Tos, 1893 and G. tropicalis Malloch, 1934. A key for the recognition of these three species is given. G. auriceps is redescribed, including the morphology of male and female terminalia and the male of G. tropicalis is described for the first time. For G. mexicana, a well-known species in the literature, only a brief diagnosis and the material examined are listed.

scholarly journals Right Knee—The Weakest Point of the Best Ultramarathon Runners of the World? A Case Study

2020 ◽  
Vol 17 (16) ◽  
pp. 5955 ◽  
Author(s):  
Robert Gajda ◽  
Paweł Walasek ◽  
Maciej Jarmuszewski
Keyword(s):  
Knee Pain ◽  
Cardiovascular Assessment ◽  
The World ◽  
Before And After ◽  
Loop Shape ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Necessary Evil ◽  
The Impact ◽  
First Time

The impact of ultramarathons (UM) on the organs, especially in professional athletes, is poorly understood. We tested a 36-year-old UM male runner before and after winning a 24-h marathon. The primary goal of the study was cardiovascular assessment. The athlete experienced right knee pain for the first time after 12 h of running (approximately 130 km), which intensified, affecting his performance. The competitors ran on a 1984 m rectangle-loop (950 × 42 m) in an atypical clockwise fashion. The winner completed 516 rectangular corners. Right knee Magnetic Resonance Imaging (MRI) one day after the run showed general overload in addition to degenerative as well as specific features associated with “turning to the right”. Re-examination after three years revealed none of these findings. Different kinds of overloading of the right lower limb, including right knee pain, were indicated in 6 of 10 competitors from the top 20, including a woman who set the world record. The affected competitors suggested as cause for discomfort the shape of the loop and running direction. They believed that changing the direction of the run during the competition and an athletics stadium loop shape on a 2000–2500 m length is better for 24-h UM runners. In the absence of technical alternatives, the “necessary evil” is a counterclockwise run (also Association of Athletics Federations IAAF recommendation). Results suggest that a one-way, clockwise, 24-h UM run had an adverse effect on the athlete’s right knee, as a result of unsymmetrical load. Organizers of 24-h UM runs should consider the shape of the competition loop and apply the principle of uniform load on the musculoskeletal system (alternate directions run). In case of technical impossibility, it would be better to run counterclockwise, which is more common, preferred by runners, and recommended by the IAAF.

scholarly journals Mutation density changes in SARS-CoV-2 are related to the pandemic stage but to a lesser extent in the dominant strain with mutations in spike and RdRp

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9703 ◽  
Author(s):  
Doğa Eskier ◽  
Aslı Suner ◽  
Gökhan Karakülah ◽  
Yavuz Oktay
Keyword(s):  
Viral Genome ◽  
Time Dependent ◽  
Origin And Evolution ◽  
Gene Level ◽  
The Us ◽  
The World ◽  
Before And After ◽  
Different Characteristics ◽  
First Time ◽  
New Mutations

Since its emergence in Wuhan, China in late 2019, the origin and evolution of SARS-CoV-2 have been among the most debated issues related to COVID-19. Throughout its spread around the world, the viral genome continued acquiring new mutations and some of them became widespread. Among them, 14408 C>T and 23403 A>G mutations in RdRp and S, respectively, became dominant in Europe and the US, which led to debates regarding their effects on the mutability and transmissibility of the virus. In this study, we aimed to investigate possible differences between time-dependent variation of mutation densities (MDe) of viral strains that carry these two mutations and those that do not. Our analyses at the genome and gene level led to two important findings: First, time-dependent changes in the average MDe of circulating SARS-CoV-2 genomes showed different characteristics before and after the beginning of April, when daily new case numbers started levelling off. Second, this pattern was much delayed or even non-existent for the “mutant” (MT) strain that harbored both 14408 C>T and 23403 A>G mutations. Although these differences were not limited to a few hotspots, it is intriguing that the MDe increase is most evident in two critical genes, S and Orf1ab, which are also the genes that harbor the defining mutations of the MT genotype. The nature of these unexpected relationships warrants further research.

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