scholarly journals Effects of Wolbachia Infection, Parasitic Order, And Time Interval On The Outcome of Inter-Strain Intrinsic Competition Between Bisexual Strain And Wolbachia-Induced Thelytokous Strain of Egg Parasitoid, Trichogramma Dendrolimi

2022 ◽  
Author(s):  
Zhou Jin-Cheng ◽  
Shang Dan ◽  
Liu Shi-Meng ◽  
Qian Qian ◽  
Liang Hong-Yu ◽  
...  
Keyword(s):  
Competitive Ability ◽  
Developmental Rate ◽  
Wolbachia Infection ◽  
Egg Parasitoid ◽  
Development Rate ◽  
Time Interval ◽  
Negative Effects ◽  
Parasitoid Species ◽  
Second Clutch ◽  
Trichogramma Dendrolimi

Abstract Parasitoids may deposit a second clutch of eggs on a host that has been parasitized by the same parasitoid species. This is termed “superparasitism”. Wolbachia infection increases the superparasitism frequency of Trichogramma females. We investigated the outcome and fitness cost of inter-strain intrinsic competition between Wolbachia-infected thelytokous strain (TDW) and uninfected bisexual strain (TDB) of Trichogramma dendrolimi. To determine the developmental rate of both strains, the size of immature stages of T. dendrolimi offspring at different times after parasitization was measured in single parasitism and superparasitism conditions. The results showed increased superparasitism by Wolbachia-infected females compared to uninfected females, regardless of the time interval between oviposition; Trichogramma females were unable to distinguish between host eggs previously parasitized by TDB or TDW females. When the first oviposition was performed by TDB females, the TDB offspring outcompeted TDW offspring deposited later. However, although the TDW offspring was deposited 8 h earlier than the TDB offspring, it gained no advantage over TDB offspring. Regardless of parasitism conditions, the differences in development rate and time between TDW and TDB offspring were not significant. This study revealed that albeit TDW females presented a higher tendency of superparasitism than TDB females, TDB offspring outcompeted TDW offspring even when the latter was deposited 8 h earlier. The negative effects of Wolbachia infection on the competitive ability of TDW offspring inside the host eggs were due to offspring’s low fitness rather than delayed development.

Developmental divergence among hatchery strains of rainbow trout (Salmo gairdneri). I. Pure strains

1985 ◽  
Vol 27 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Moira M. Ferguson ◽  
Roy G. Danzmann ◽  
Fred W. Allendorf
Keyword(s):  
Rainbow Trout ◽  
Morphological Analysis ◽  
Developmental Process ◽  
Developmental Rate ◽  
Electrophoretic Analysis ◽  
Development Rate ◽  
Salmo Gairdneri ◽  
Glucosephosphate Isomerase ◽  
Hatching Time ◽  
Developmental Divergence

We compare the developmental rate of six closely related hatchery strains of rainbow trout. Hatching time, morphological analysis, and the pattern of ontogenetic change in lactate dehydrogenase, malate dehydrogenase, glucosephosphate isomerase, and phosphoglucomutase activities indicate significant differences in developmental rate between strains. There is close concordance among the different measures of developmental rate. Strains with higher levels of heterozygosity, as estimated from electrophoretic analysis of 42 loci, developed faster than less heterozygous strains. The variation in developmental rate in these closely related strains indicates that there is substantial genetic variation affecting the developmental process in rainbow trout.Key words: development rate, intraspecific variation, rainbow trout.

scholarly journals An algorithm for the estimation of road traffic space mean speeds from double loop detector data

2016 ◽  
Author(s):  
Margarita Martínez-Díaz ◽  
Ignacio Pérez Pérez
Keyword(s):  
Traffic Management ◽  
Road Traffic ◽  
Time Interval ◽  
Double Loop ◽  
Negative Effects ◽  
Loop Detectors ◽  
The Common ◽  
Log Normal ◽  
The Individual ◽  
Log Normal Distribution

Most algorithms trying to analyze or forecast road traffic rely on many inputs, but in practice, calculations are usually limited by the available data and measurement equipment. Generally, some of these inputs are substituted by raw or even inappropriate estimations, which in some cases come into conflict with the fundamentals of traffic flow theory. This paper refers to one common example of these bad practices. Many traffic management centres depend on the data provided by double loop detectors, which supply, among others, vehicle speeds. The common data treatment is to compute the arithmetic mean of these speeds over different aggregation periods (i.e. the time mean speeds). Time mean speed is not consistent with Edie’s generalized definitions of traffic variables, and therefore it is not the average speed which relates flow to density. This means that current practice begins with an error that can have negative effects in later studies and applications. The algorithm introduced in this paper enables easily the estimation of space mean speeds from the data provided by the loops. It is based on two key hypotheses: stationarity of traffic and log-normal distribution of the individual speeds in each time interval of aggregation. It could also be used in case of transient traffic as a part of any data fusion methodology.DOI: http://dx.doi.org/10.4995/CIT2016.2016.3208 

scholarly journals EFFECTS OF WELDING PARAMETERS, TIME INTERVAL AND PREHEATING ON RESIDUAL STRESS AND DISTORTION OF JOINING ST52 STIFFENER RING IN AN AISI 4130 TUBULAR SHELL

2020 ◽  
Vol 3 (1) ◽  
pp. 11-15
Author(s):  
Alireza M. Haghighi ◽  
Farhad S. Samani
Keyword(s):  
Residual Stress ◽  
Welding Current ◽  
Welding Parameters ◽  
Time Interval ◽  
Negative Effects ◽  
Short Term ◽  
Welding Line ◽  
Aisi 4130 ◽  
Comparison Of The Results

Stiffener rings and stringers are used commonly in offshore and aerospace structures. Welding the stiffener to the structure causes the appearance of residual stress and distortion that leads to short-term and long-term negative effects. Residual stress and distortion of welding have destructive effects such as deformation, brittle fracture, and fatigue of the welded structures. This paper aims to investigate the effects of preheating, time interval and welding parameters such as welding current and speed on residual stress and distortion of joining an ST52-3N (DIN 1.0570) T-shape stiffener ring to an AISI 4130 (DIN 1.7218) thin-walled tubular shell by eleven pairs of welding line in both sides of the ring by means of finite element method (FEM). Results in tangent (longitudinal), axial and radial directions have been compared and the best welding methods proposed. After the comparison of the results, simultaneous welding both sides of the ring with preheating presented as the best method with less distortion and residual stresses among the studied conditions. The correctness of the FEM confirmed by the validation of the results.

The Design of an IEEE 1588 End-to-End Transparent Ethernet Switch

2021 ◽  
Author(s):  
◽  
Caleb Gordon
Keyword(s):  
Packet Delay ◽  
Time Interval ◽  
Path Delay ◽  
Negative Effects ◽  
Ieee 1588 ◽  
Precision Time ◽  
End To End ◽  
And Control ◽  
Measurement And Control ◽  
Ethernet Switch

<p>In measurement and control systems there is often a need to synchronise distributed clocks. Traditionally, synchronisation has been achieved using a dedicated medium to convey time information, typically using the IRIG-B serial protocol. The precision time protocol (IEEE 1588) has been designed as an improvement to current methods of synchronisation within a distributed network of devices. IEEE 1588 is a message based protocol that can be implemented across packet based networks including, but not limited to, Ethernet. Standard Ethernet switches introduce a variable delay to packets that inhibits path delay measurements. Transparent switches have been introduced to measure and adjust for packet delay, thus removing the negative effects that these variations cause.  This thesis describes the hardware and firmware design of an IEEE 1588 transparent end-to-end Ethernet switch for Tekron International Ltd based in Lower Hutt, New Zealand. This switch has the ability to monitor all Ethernet traffic, identify IEEE 1588 timing packets, measure the delay that these packets experience while passing through the switch, and account for this delay by adjusting a time-interval field of the packet as it is leaving the switch. This process takes place at the operational speed of the port, and without introducing significant delay. Time-interval measurements can be made using a high-precision timestamp unit with a resolution of 1 ns. The total jitter introduced by this measurement process is just 4.5 ns through a single switch.</p>

scholarly journals Gene Characterization and Enzymatic Activities Related to Trehalose Metabolism of In Vitro Reared Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) under Sustained Cold Stress

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 767
Author(s):  
Xin Lü ◽  
Shi-chou Han ◽  
Zhi-gang Li ◽  
Li-ying Li ◽  
Jun Li
Keyword(s):  
Cold Tolerance ◽  
Enzyme Activities ◽  
Low Temperatures ◽  
Insect Pests ◽  
Egg Parasitoid ◽  
Threshold Temperature ◽  
Gene Expressions ◽  
Gene Characterization ◽  
Trichogramma Dendrolimi

Trichogramma spp. is an important egg parasitoid wasp for biocontrol of agriculture and forestry insect pests. Trehalose serves as an energy source or stress protectant for insects. To study the potential role of trehalose in cold resistance on an egg parasitoid, cDNA for trehalose-6-phosphate synthase (TPS) and soluble trehalase (TRE) from Trichogramma dendrolimi were cloned and characterized. Gene expressions and enzyme activities of TdTPS and TdTRE were determined in larvae, prepupae, pupae, and adults at sustained low temperatures, 13 °C and 16 °C. TdTPS and TdTRE expressions had similar patterns with higher levels in prepupae at 13 °C and 16 °C. TdTPS enzyme activities increased with a decrease of temperature, and TdTRE activity in prepupae decreased sharply at these two low temperatures. In vitro reared T. dendrolimi could complete entire development above 13 °C, and the development period was prolonged without cold injury. Results indicated trehalose might regulate growth and the metabolic process of cold tolerance. Moreover, 13 °C is the cold tolerance threshold temperature and the prepupal stage is a critical developmental period for in vitro reared T. dendrolimi. These findings identify a low cost, prolonged development rearing method, and the cold tolerance for T. dendrolimi, which will facilitate improved mass rearing methods for biocontrol.

scholarly journals Sexual dimorphism and sex-biased gene expression in an egg parasitoid species, Anastatus disparis

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Peng-Cheng Liu ◽  
De-Jun Hao ◽  
Hao-Yuan Hu ◽  
Jian-Rong Wei
Keyword(s):  
Gene Expression ◽  
Sexual Dimorphism ◽  
Egg Parasitoid ◽  
Parasitoid Species

scholarly journals Wolbachia infection reduces sperm competitive ability in an insect

2006 ◽  
Vol 273 (1593) ◽  
pp. 1455-1458 ◽  
Author(s):  
Fleur E Champion de Crespigny ◽  
Nina Wedell
Keyword(s):  
Population Dynamics ◽  
Sperm Competition ◽  
Empirical Evidence ◽  
Reproductive Strategies ◽  
Competitive Ability ◽  
Cytoplasmic Incompatibility ◽  
Wolbachia Infection ◽  
Sperm Production ◽  
Fitness Costs ◽  
Wolbachia Pipientis

The maternally inherited bacterium Wolbachia pipientis imposes significant fitness costs on its hosts. One such cost is decreased sperm production resulting in reduced fertility of male Drosophila simulans infected with cytoplasmic incompatibility (CI) inducing Wolbachia . We tested the hypothesis that Wolbachia infection affects sperm competitive ability and found that Wolbachia infection is indeed associated with reduced success in sperm competition in non-virgin males. In the second male role, infected males sired 71% of the offspring whereas uninfected males sired 82% of offspring. This is the first empirical evidence indicating that Wolbachia infection deleteriously affects sperm competition and raises the possibility that polyandrous females can utilize differential sperm competitive ability to bias the paternity of broods and avoid the selfish manipulations of Wolbachia . This suggests a relationship between Wolbachia infection and host reproductive strategies. These findings also have important consequences for Wolbachia population dynamics because the transmission advantage of Wolbachia is likely to be undermined by sperm competition.

scholarly journals Identification of “bottlenecks” in the systems of adaptability in peach cultivars to specific abiotic factors limiting plant growth and development and affecting individual phases of ontogenesis to develop optimal algorithms for further breeding

2021 ◽  
Vol 181 (4) ◽  
pp. 112-119
Author(s):  
I. A. Dragavtseva ◽  
V. A. Dragavtsev ◽  
A. P. Kuznetsova ◽  
A. V. Klyukina
Keyword(s):  
Low Temperatures ◽  
Abiotic Factors ◽  
Time Interval ◽  
Environment Interaction ◽  
Developmental Phase ◽  
Negative Effects ◽  
Genotype Environment Interaction ◽  
Depth Analysis ◽  
New Strategy ◽  
Developmental Phases

Modern breeding, especially when fruit plants cultivated for decades at the same location are concerned, requires a new strategy to develop cultivars resistant to abiotic limfactors of the environment. A more in-depth analysis of genotype–environment interaction phenomena is needed, as modern studies have shown that the level of plant productivity and yields is determined not by specific “genes of quantitative traits”, but mainly by the emergent (newly occurring when a lim-factor of the environment changes at the ontogenetic and phytocenotic levels) effects of the genotype–environment interaction (GEI). New knowledge is needed about the values of contributions to the productivity of a cultivar made by each of the genetic–physiological systems of plant adaptability (GPS-ad) when exposed to a particular lim-factor of the environment at a particular phase of ontogenesis. For the first time, aiming at finding promising peach genotypes for further breeding, we studied their adaptability to low temperatures in different horticulture zones of Krasnodar Territory.Shifts in the effects of low-temperature environmental stressors in the developmental phases of cultivars (produced by climate change) were analyzed in the time interval of 1985–2018.The presence of hereditary adaptive reserves for increasing peach productivity for each phase of development in the process of studying the phenomena of GEI was disclosed. Recommendations are given to breeders on phase-to-phase breeding of future cultivars: how to protect their production process at each developmental phase from negative effects of low temperatures. 

Sign in / Sign up

Export Citation Format

Share Document