Different breeding conditions affect the morphological variability in larvae of Platytrombidium fasciatum (Trombidiformes: Microtrombidiidae)

2021 ◽  
Vol 26 (6) ◽  
pp. 1055-1066
Author(s):  
Anna Derdak ◽  
Magdalena Felska ◽  
Joanna Mąkol ◽  
Paula Zajkowska

The impact of temperature and light/dark cycle on morphological traits of Platytrombidium fasciatum was examined in larvae obtained from field-collected females. The eggs laid by 65 females at laboratory conditions were assigned to four experimental groups. Varied thermal conditions affected the values of nine out of 46 (nonparametric MANOVA) and 26 out of 37 (LDA) morphometric traits in larvae. As many as six quantitative traits differed significantly irrespective of the method (MANOVA, LDA) applied. The analysis of the metric traits within the dorsal sclerites revealed that the lower mean temperature over the period of egg incubation, translated into longer duration of development, was associated with an increase in distance between the bases of 3rd pair of non-sensillary setae on scutum at the decrease in distance between the bases of 2nd pair of non-sensillary setae as well as in distance between the level of sensilla and the posterior edge of the sclerite. In the case of 40 measurable traits in larvae of P. fasciatum, the variability going beyond the hitherto knowledge on the species was observed.

2021 ◽  
Vol 99 (4) ◽  
Author(s):  
Ryan M Knuth ◽  
Whitney C Stewart ◽  
Joshua B Taylor ◽  
Bledar Bisha ◽  
Carl J Yeoman ◽  
...  

Abstract Mastitis is an economically important disease and its subclinical state is difficult to diagnose, which makes mitigation more challenging. The objectives of this study were to screen clinically healthy ewes in order to 1) identify cultivable microbial species in milk, 2) evaluate somatic cell count (SCC) thresholds associated with intramammary infection, and 3) estimate relationships between udder and teat morphometric traits, SCC, and ewe productivity. Milk was collected from two flocks in early (<5 d) and peak (30 to 45 d) lactation to quantify SCC (n = 530) and numerate cultivable microbial species by culture-based isolation followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS; n = 243) identification. Within flock and lactation stage, 11% to 74% (mean = 36%) of samples were culture positive. More than 50 unique identifications were classified by MALDI-TOF MS analysis, and Bacillus licheniformis (18% to 27%), Micrococcus flavus (25%), Bacillus amyloliquefaciens (7% to 18%), and Staphylococcus epidermidis (26%) were among the most common within flock and across lactation stage. Optimum SCC thresholds to identify culture-positive samples ranged from 175 × 103 to 1,675 × 103 cells/mL. Ewe productivity was assessed as total 120-d adjusted litter weight (LW120) and analyzed within flock with breed, parity, year, and the linear covariate of log10 SCC (LSCC) at early or peak lactation. Although dependent on lactation stage and year, each 1-unit increase in LSCC (e.g., an increase in SCC from 100 × 103 to 1,000 × 103 cells/mL) was predicted to decrease LW120 between 9.5 and 16.1 kg when significant. Udder and teat traits included udder circumference, teat length, teat placement, and degree of separation of the udder halves. Correlations between traits were generally low to moderate within and across lactation stage and most were not consistently predictive of ewe LSCC. Overall, the frequencies of bacteria-positive milk samples indicated that subclinical mastitis (SCM) is common in these flocks and can impact ewe productivity. Therefore, future research is warranted to investigate pathways and timing of microbial invasion, genomic regions associated with susceptibility, and husbandry to mitigate the impact of SCM in extensively managed ewes.


2021 ◽  
Vol 13 (6) ◽  
pp. 3054
Author(s):  
Renata Tubelo ◽  
Lucelia Rodrigues ◽  
Mark Gillott ◽  
May Zune

In Brazil, the delivery of homes for low-inc ome households is dictated by costs rather than performance. Issues such as the impact of climate change, affordability of operational energy use, and lack of energy security are not taken into account, even though they can severely impact the occupants. In this work, the authors evaluated the thermal performance of two affordable houses as-built and after the integration of envelope improvements. A new replicable method to evaluate the cost-effectiveness of these improvements was proposed. The case study houses comprise the most common affordable housing type delivered widely across Brazil and a proposition of a better affordable housing solution, built in Porto Alegre, southern Brazil, integrating passive design strategies to increase thermal comfort. The findings reveal a potential for improving indoor thermal conditions by up to 76% and 73%, respectively, if costs are not a concern, and 40% and 45% with a cost increase of 12% and 9% if a comfort criterion of 20–25 °C was considered. Equations to estimate costs of improvements in affordable housing were developed. The authors concluded that there is a great scope for building envelope optimisation, and that this is still possible without significant impact on budget.


2001 ◽  
Vol 9 (2) ◽  
pp. 130-134 ◽  
Author(s):  
Gonçalo R Abecasis ◽  
Stacey S Cherny ◽  
Lon R Cardon

2011 ◽  
Vol 39 (No. 2) ◽  
pp. 59-67 ◽  
Author(s):  
I. Doležalová ◽  
A. Lebeda ◽  
M. Dziechciarková ◽  
E. Křístková ◽  
D. Astley ◽  
...  

Fifty one accessions of nineteen Lactuca species, the hybrid L. serriola × L. sativa and the related species Mycelis muralis were evaluated for morphological variability, esterase (EST) polymorphism, Amplified Fragment Length Polymorphism (AFLP) and relative DNA content. Sixteen Lactuca accessions were classified taxonomically on the basis of morphology, isozyme analysis and AFLP. Twenty-eight bands (isoforms) of EST were recorded allowing 82% of accessions to be distinguished. The relative DNA content, measured using flow-cytometry (DAPI staining), ranged from 2.02 pg in L. capensis to 17.96 pg in L. canadensis. The results from AFLP analysis and the relative DNA content measurement corresponded well with recent taxonomic classification of the genus Lactuca.  


2014 ◽  
Vol 4 (2) ◽  
pp. 192-221 ◽  
Author(s):  
Beatriz López Prego ◽  
Alison Gabriele

The study tests representational and computational accounts of morphological variability in English-speaking learners of Spanish by examining performance on gender and number agreement under different task demands. Second language (L2) learners took either a Speeded grammaticality judgment task (GJT) or an Untimed GJT. The tasks targeted agreement violations of two types: errors in the use of ‘default’ morphology and errors involving ‘feature clashes’ (McCarthy, 2008). In addition, three groups of native speakers took the Speeded GJT at three different presentation rates to examine whether native speakers under a processing burden perform similarly to learners. Natives in the fastest speed performed better with feature clash errors for both gender and number. Learners showed the same pattern for number, but performed better with default errors in gender, suggesting different effects of processing demands for properties unique to the L2. On the Untimed GJT, a subset of advanced learners showed perfect performance with both gender and number.


2019 ◽  
Vol 97 ◽  
pp. 01041
Author(s):  
Adam Ujma ◽  
Marta Pomada

Designers more and more often choose facade systems with ventilated layers for external walls, especially in the case of new buildings. They are also used to modernize existing buildings. Mechanical connectors are a characteristic element of these constructions. Often, they are ignored in calculating the heat balance of rooms and the entire building. Because they pierce the thermal insulation layer they cause point thermal bridges. The influence of thermal point bridges, usually made of aluminum, i.e. a material with very high thermal conductivity, for heat transfer turns out to be significant. Such thermal bridges significantly increase heat losses through building partitions. This situation increases the heat demand in the rooms to compensate for the heat loss. The article presents the results of the analysis of the impact of mechanical fasteners in ventilated facade systems on heat transfer in the building envelope. The influence of various materials and constructional solutions on the thermal conditions in these walls was investigated.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Baraa A. Rajab

The mastery of morphological structure and vocabulary acquisition are significantly associated. However, the association between the abilities of L2 learners to manipulate morphological elements and develop vocabulary size with native Arabic speakers needs to be assessed. This study assesses the impact of morphological knowledge on lexical acquisition and processing among English-speaking learners of Arabic. The study focused on gender (masculine/feminine) and the complete number system (singular/dual/plural) by native English speakers. The error rates and error patterns were analysed carefully to provide insight into the learner’s interlanguage grammar through the experiment. The experimental study design was used. The study sample included 40 of L2 Arabic speakers from Arabic language courses at major universities in Northern Virginia and Maryland. These were native English speakers with no exposure to Arabic before their enrolment in the university. The sample was divided into three groups (Group I, individual in the second year of Arabic program, Group II, individual in 3rd or 4th year of the program, and Group III control group, five native speakers of Arabic). Different tasks were presented to the groups, where PsychoPy software was used for task presentation. Audacity Version 2.0 was audio-recorded, transcribed, and coded by the experimenter. The production and comprehension test revealed that morphological problems are prevalent at the advanced proficiency level. It showed the role of animacy for the morphological variability and higher agreement accuracy for human targets. It concluded that morphological variability in L2 Arabic remains a persistent problem even at advanced levels of proficiency, extending to comprehension.


2012 ◽  
Vol 7 (No. 4) ◽  
pp. 125-137 ◽  
Author(s):  
J. Votrubová ◽  
M. Dohnal ◽  
T. Vogel ◽  
M. Tesař

Soil water and heat transport plays an important role in various hydrologic, agricultural, and industrial applications. Accordingly, an increasing attention is paid to relevant simulation models. In the present study, soil thermal conditions at a mountain meadow during the vegetation season were simulated. A dual-continuum model of coupled water and heat transport was employed to account for preferential flow effects. Data collected at an experimental site in the Šumava Mountains, southern Bohemia, during the vegetation season 2009 were employed. Soil hydraulic properties (retention curve and hydraulic conductivity) determined by independent soil tests were used. Unavailable hydraulic parameters were adjusted to obtain satisfactory hydraulic model performance. Soil thermal properties were estimated based on values found in literature without further optimization. Three different approaches were used to approximate the soil thermal conductivity function, λ(θ): (i) relationships provided by Chung and Horton (ii) linear estimates as described by Loukili, Woodbury and Snelgrove, (iii) methodology proposed by Côté and Konrad. The simulated thermal conditions were compared to those observed. The impact of different soil thermal conductivity approximations on the heat transport simulation results was analysed. The differences between the simulation results in terms of the soil temperature were small. Regarding the surface soil heat flux, these differences became substantial. More realistic simulations were obtained using λ(θ) estimates based on the soil texture and composition. The differences between these two, related to neglecting vs. considering λ(θ) non-linearity, were found negligible.


2019 ◽  
Vol 887 ◽  
pp. 428-434
Author(s):  
Dorcas A. Ayeni ◽  
Olaniyi O. Aluko ◽  
Morisade O. Adegbie

Man requires a thermal environment that is within the range of his adaptive capacity and if this fluctuates outside the normal, a reaction is required beyond its adaptive capacity which results to health challenges. Therefore, the aim of building design in the tropical region is to minimize the heat gain indoors and enhance evaporative cooling of the occupants of the space so as to achieve thermal comfort. In most cases, the passive technologies are not adequate in moderating indoor climate for human comfort thereby relying on active energy technique to provide the needed comfort for the building users. The need for the use of vegetation as a panacea for achieving comfortable indoor thermal conditions in housing is recognised by architects globally. However, the practice by architects in Nigeria is still at the lower ebb. The thrust of this paper therefore is to examine the impact of vegetation in solar control reducing thermal discomfort in housing thereby enhancing the energy performance of the buildings. Using secondary data, the paper identifies the benefits of vegetation in and around buildings to include improvement of indoor air quality through the aesthetics quality of the environment and concludes that vegetation in and around building will in no small measure contributes to saving energy consumption.


1993 ◽  
Vol 265 (4) ◽  
pp. R749-R755 ◽  
Author(s):  
T. M. Lee

The importance of maternal photoperiodic history during lactation on the postnatal development of meadow vole pups was tested by cross-fostering pups on the day of birth between photorefractory females (housed for 26 wk in a 10:14-h light-dark cycle before mating) and photosensitive females (housed for 2 wk in a 10:14-h light-dark cycle before mating). Control pups were cross-fostered to females with the same photoperiodic history as the gestational dam. Somatic growth and food intake of cross-fostered pups were influenced by the photoperiod of the postnatal lactating dam. Pre- and postnatal maternal photoperiodic history interacted with the sex of the offspring to influence reproductive development. Pelage development was determined exclusively by the prenatal maternal photoperiodic history. The impact of a postnatal maternal influence on pup development of photoperiod-sensitive traits is discussed.


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