Ecological and geographical variations in the siphonal index of Culex pipiens larvae (Diptera: Culicidae)

1996 ◽  
Vol 86 (3) ◽  
pp. 281-287 ◽  
Author(s):  
E.B. Vinogradova ◽  
S.Ya. Reznik ◽  
E.S. Kuprijanova

AbstractCulex pipiens Linnaeus is represented by two forms: the form molestus which is autogenous, stenagamous and has no reproductive diapause, and the form pipiens which is anautogenous, eurygamous and diapauses. The ecological, physiological and geographical variations in the larval siphonal index of C. pipiens (the ratio of the length of the siphon to its width at the base) was investigated using both original measurements and previously published data. In all, data were used from 259 collections from open water bodies (marshes, ditches, holes, barrels, etc.) and underground waters (house basements) in areas of Europe, Asia and part of Africa. Autogeny was studied in some cases by dissection of females. In C. pipiens the mean siphonal index was strongly correlated with ecology (water body type) and adult physiology (autogeny). In spite of high geographical and individual variation, which makes the identification of individual larvae difficult, the mean siphonal index can be used with certainty for the differentiation of populations of the two forms of C. pipiens.

1953 ◽  
Vol 4 (2) ◽  
pp. 204 ◽  
Author(s):  
FHW Morley

A study of published data on the fold scores of certain breed crosses, backcrosses, and filial generations suggests that causes of variation in skinfold score act geometrically. A logarithmic transformation increased the accuracy of prediction of F2 and backcross scores. Data from selection experiments on Merinos at Trangie were analysed using both arithmetic and logarithmic scales. Heritability of breech fold score was estimated as 0.45 on an arithmetic scale, 0.55 on the logarithmic scale. The mean and variance within groups of Merinos with different means were strongly correlated on the arithmetic scale, but this correlation was removed by the logarithmic transformation, resulting variances being approximately constant. Freedom from folds showed strong potence on both arithmetic and logarithmic scales. Theoretical implications of potence and geometric action appear to be confirmed by available data.


1989 ◽  
Vol 54 (1) ◽  
pp. 101-105 ◽  
Author(s):  
J. Bruce Tomblin ◽  
Cynthia M. Shonrock ◽  
James C. Hardy

The extent to which the Minnesota Child Development Inventory (MCDI), could be used to estimate levels of language development in 2-year-old children was examined. Fifty-seven children between 23 and 28 months were given the Sequenced Inventory of Communication Development (SICD), and at the same time a parent completed the MCDI. In addition the mean length of utterance (MLU) was obtained for each child from a spontaneous speech sample. The MCDI Expressive Language scale was found to be a strong predictor of both the SICD Expressive scale and MLU. The MCDI Comprehension-Conceptual scale, presumably a receptive language measure, was moderately correlated with the SICD Receptive scale; however, it was also strongly correlated with the expressive measures. These results demonstrated that the Expressive Language scale of the MCDI was a valid predictor of expressive language for 2-year-old children. The MCDI Comprehension-Conceptual scale appeared to assess both receptive and expressive language, thus complicating its interpretation.


2021 ◽  
Vol 9 ◽  
pp. 205031212110011
Author(s):  
Thabit Alotaibi ◽  
Abdulrhman Abuhaimed ◽  
Mohammed Alshahrani ◽  
Ahmed Albdelhady ◽  
Yousef Almubarak ◽  
...  

Background: The management of Acinetobacter baumannii infection is considered a challenge especially in an intensive care setting. The resistance rate makes it difficult to manage and is believed to lead to higher mortality. We aim to investigate the prevalence of Acinetobacter baumannii and explore how different antibiotic regimens could impact patient outcomes as there are no available published data to reflect our population in our region. Methods: We conducted a retrospective review of all infected adult patients admitted to the intensive care unit at King Fahad University Hospital with a confirmed laboratory diagnosis of Acinetobacter baumannii from 1 January 2013 until 31 December 2017. Positive cultures were obtained from the microbiology department and those meeting the inclusive criteria were selected. Variables were analyzed using descriptive analysis and cross-tabulation. Results were further reviewed and audited by blinded co-authors. Results: A comprehensive review of data identified 198 patients with Acinetobacter baumannii. The prevalence of Acinetobacter baumannii is 3.37%, and the overall mortality rate is 40.81%. Our sample consisted mainly of male patients, that is, 68.7%, with a mean age of 49 years, and the mean age of female patients was 56 years. The mean age of survivors was less than that of non-survivors, that is, 44.95 years of age. We observed that prior antibiotic use was higher in non-survivors compared to survivors. From the review of treatment provided for patients infected with Acinetobacter baumannii, 65 were treated with colistin alone, 18 were treated with carbapenems, and 22 were treated with a combination of both carbapenems and colistin. The mean length of stay of Acinetobacter baumannii–infected patients was 20.25 days. We found that the survival rates among patients who received carbapenems were higher compared to those who received colistin. Conclusion: We believe that multidrug-resistant Acinetobacter baumannii is prevalent and associated with a higher mortality rate and represents a challenging case for every intensive care unit physician. Further prospective studies are needed.


2003 ◽  
Vol 34 (4) ◽  
pp. 361-386 ◽  
Author(s):  
L. Sipelgas ◽  
H. Arst ◽  
K. Kallio ◽  
A. Erm ◽  
P. Oja ◽  
...  

The main objective of the present study is to test various methods for describing the absorption spectra of coloured dissolved organic matter (CDOM) and to determine the numerical values of some optical parameters of CDOM in lakes with diverse water quality. First, the parameters of an exponential model in different spectral intervals were determined. In addition, the suitability of some other models for the approximation of CDOM spectra was estimated. Specific absorption coefficients of CDOM were calculated from the absorption coefficients and dissolved organic carbon (DOC) concentrations. The experimental initial data were differences between spectral attenuation coefficients of filtered and distilled water. Two datasets were used: 1) for 13 Estonian and 7 Finnish lakes (altogether 404 spectra between 350 and 700 nm) measured by the Estonian Marine Institute (EMI); 2) for 10 Finnish lakes (73 spectra) measured by the Finnish Environment Institute (FEI). The spectra of CDOM absorption coefficients (aCDOM) were calculated from experimental data taking into account the correction due to scattering properties of colloids in the filtered water. The total content of CDOM in natural waters of Estonian and Finnish lakes was expressed by means of aCDOM at the wavelength of 380 nm. It varied significantly, from 0.71 to 19.5 m−1, the mean value (of all the investigated lakes) being around 6.6 m−1. Slopes of the exponential approximation varied widely, from 0.006 to 0.03 nm−1. Averaged over all lakes values of slope for the interval 380-500 nm obtained from the EMI dataset are close to those obtained from the FEI dataset: from 0.014 nm−1 (without correction) to 0.016-0.017 nm-1 (with different types of correction). These results are in good correspondence with most published data. Attempts to describe the spectra in the region of 350-700 nm by means of hyperexponential functions (∽ exp(-αλη)) show that: (1) η < 1 (in the case of traditional exponential approximation η = 1); (2) a promising idea is to seek the best fit only for wavelengths λ > λ1, where λ1 will be chosen taking into account the real shape of aCDOM spectra. The mean value of the specific absorption coefficient (a*CDOM) at the wavelength 380 nm obtained in this study (0.44 L mg−1 m−1) is close to the values published in the literature, if we assume that a*CDOM (380) is calculated using the data of dissolved organic matter (DOM). The optically non-active fraction of DOM in our study was high and therefore a*CDOM (380) was considerably higher (1.01 L mg−1 m−1) than a*CDOM (380). The results of the present work could be used in the modeling of underwater light field as well as in the interpretation of radiation measurements and optical remote sensing results.


Author(s):  
Claus Orendt

Based on data from monitoring in north-east Germany (Land Brandenburg) over a decade, chironomid taxa and their abundances were analysed for their preferences for certain running water types and degradation levels. A detrended correspondence analysis (DCA) revealed that the distribution of the taxa was determined by both, degradation level and water body type. A series of taxa was positively or negatively correlated to degradation, however, frequently only in certain water body types. In other types, they played no major role or were evenly distributed along the degradation gradient. Higher correlations were found for taxa favouring ‘good’ and 'poor' or 'bad' conditions than for preferers of ‘moderate’ status. The results allow to validate indices and weigths of indicators derived from high frequencies of the taxa in certain one or more quality class(es). The preferred ocurrencies elaborated have to be discussed or tested for plausiblity before using or evaluating powerful indicator taxa for classifications or revisions in assessment practice. A reduction of the taxonomical precision to genus level lowered the statistical significance and requires careful examination of the species preferences of the genus.


2014 ◽  
Vol 64 ◽  
pp. 48-53 ◽  
Author(s):  
David S. Kang ◽  
David L. Denlinger ◽  
Cheolho Sim

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2569 ◽  
Author(s):  
Christos Keramydas ◽  
Georgios Papadopoulos ◽  
Leonidas Ntziachristos ◽  
Ting-Shek Lo ◽  
Kwok-Lam Ng ◽  
...  

This study investigates pollutant emissions and fuel consumption of six Euro VI hybrid-diesel public transport buses operating on different scheduled routes in a metropolitan urban road network. Portable emission measurement systems (PEMS) are used in measurements and results are compared to those obtained from a paired number of Euro V conventional buses of the same body type used as control over the same routes. The selected routes vary from urban to highway driving and the experimentation was conducted over the first half of 2015. The available emissions data correspond to a wide range of driving, operating, and ambient conditions. Fuel consumption, distance- and energy-based emission levels are derived and presented in a comparative manner. The effect of different factors, including speed, ambient temperature, and road grade on fuel consumption and emissions performance is investigated. Mean fuel consumption of hybrid buses was found 6.1% lower than conventional ones, from 20% lower up to 16% higher, over six routes tested in total. The mean route difference between the two technologies was not statistically significant. Air conditioning decreased consumption benefits of the hybrid buses. Decrease of the mean route speed from 15 km h−1 tο 8 km h−1 increased the hybrid buses consumption by 63%. Nitrogen oxides (NOx) emissions of the Euro VI hybrid buses were 93 ± 5% lower than conventional Euro V ones. Nitrous oxide (N2O) emissions from hybrid Euro VI buses made up 5.9% of total greenhouse gas emissions and largely offset carbon dioxide (CO2) benefits. The results suggest that hybrid urban buses need to be assessed under realistic operation and environmental conditions to assess their true environmental and fuel consumption benefits.


2010 ◽  
Vol 4 (3) ◽  
pp. 1151-1194
Author(s):  
A. Fischer

Abstract. Glacier mass balance is measured with the direct or the geodetic method. In this study, the geodetic mass balances of six Austrian glaciers in 19 periods between 1953 and 2006 are compared to the direct mass balances in the same periods. The mean annual geodetic mass balance for all periods is −0.5 m w.e./year. The mean difference between the geodetic and the direct data is −0.7 m w.e., the minimum −7.3 m w.e. and the maximum 5.6 m w.e. The accuracy of geodetic mass balance resulting from the accuracy of the DEMs ranges from 2 m w.e. for photogrammetric data to 0.002 m w.e. for LIDAR data. Basal melt, seasonal snow cover and density changes of the surface layer contribute up to 0.7 m w.e. for the period of 10 years to the difference to the direct method. The characteristics of published data of Griesgletscher, Gulkana Glacier, Lemon Creek glacier, South Cascade, Storbreen, Storglaciären, and Zongo Glacier is similar to these Austrian glaciers. For 26 analyzed periods with an average length of 18 years the mean difference between the geodetic and the direct data is −0.4 m w.e., the minimum −7.2 m w.e. and the maximum 3.6 m w.e. Longer periods between the acquisition of the DEMs do not necessarily result in a higher accuracy of the geodetic mass balance. Specific glaciers show specific trends of the difference between the direct and the geodetic data according to their type and state. In conclusion, geodetic and direct mass balance data are complementary, but differ systematically.


2017 ◽  
Vol 4 (8) ◽  
pp. 301-305
Author(s):  
Matouke M. Moise

The investigation of length-weight relationship and condition factor are very relevant indices to ascertain the health of fish in the water body. Length-weigh relationship and condition factor of Hyperopisus bebe (Lacepede, 1803) (Actinopterygii: Osteoglossiformes: Mormyridae) in River Galma, Zaria, Kaduna State, Nigeria, were assessed. The mean length and mean weigh in male and female were 26.703 cm +/- 0.51 cm and 25.32 cm +/- 0.898 cm; 158.2 g +/- 10.1 g and 95.91 g +/- 9.26 g, respectively. The exponent or growth pattern 'b' values for male and female were 2.009 and 2.176. The condition factor for male and female were 0.59 and 0.83, respectively. The negative allometric growth pattern and poor condition factor might be due to the poor water quality in the fish ecosystem and should be regarded with concern.


2012 ◽  
Vol 6 (2) ◽  
pp. 479-491 ◽  
Author(s):  
A. I. Weiss ◽  
J. C. King ◽  
T. A. Lachlan-Cope ◽  
R. S. Ladkin

Abstract. This study investigates the surface albedo of the sea ice areas adjacent to the Antarctic Peninsula during the austral summer. Aircraft measurements of the surface albedo, which were conducted in the sea ice areas of the Weddell and Bellingshausen Seas show significant differences between these two regions. The averaged surface albedo varied between 0.13 and 0.81. The ice cover of the Bellingshausen Sea consisted mainly of first year ice and the sea surface showed an averaged sea ice albedo of αi = 0.64 ± 0.2 (± standard deviation). The mean sea ice albedo of the pack ice area in the western Weddell Sea was αi = 0.75 ± 0.05. In the southern Weddell Sea, where new, young sea ice prevailed, a mean albedo value of αi = 0.38 ± 0.08 was observed. Relatively warm open water and thin, newly formed ice had the lowest albedo values, whereas relatively cold and snow covered pack ice had the highest albedo values. All sea ice areas consisted of a mixture of a large range of different sea ice types. An investigation of commonly used parameterizations of albedo as a function of surface temperature in the Weddell and Bellingshausen Sea ice areas showed that the albedo parameterizations do not work well for areas with new, young ice.


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