A second diapause in Wyeomyia smithii: seasonal incidence and maintenance by photoperiod

1975 ◽  
Vol 53 (2) ◽  
pp. 215-221 ◽  
Author(s):  
L. P. Lounibos ◽  
W. E. Bradshaw
Keyword(s):  
Larval Instar ◽  
Fourth Instar ◽  
Continuous Exposure ◽  
Seasonal Incidence ◽  
Wyeomyia Smithii ◽  
The Third ◽  
Critical Photoperiod ◽  
Plant Habitat ◽  
Short Days

Wyeomyia smithii ordinarily diapauses in the third larval instar, but a second, photoperiodically maintained developmental arrest may occur in the fourth instar. Two years of sampling from a Massachusetts bog revealed that the fourth-instar diapause phenotype is most abundant in the spring after the termination of third-instar diapause, and in the fall when a new overwintering generation of third instars accumulates in the pitcher-plant habitat. Fourth-instar larvae from this population cannot, however, survive the winter. This mortality during winter is apparently balanced by advantages that a second diapause confers upon the mosquito population in the spring.Fourth-instar diapause may be induced from diapausing third-instar larvae in the laboratory by a brief exposure to long days followed by short days, or by a long-term exposure to short days at 25 °C. Continuous exposure to long days readily terminates fourth-instar diapause. The critical photoperiod and number of long days required for the termination of diapause is similar for larvae which diapause in either the third or fourth instar.

Photoperiodic control of development in the pitcher-plant mosquito, Wyeomyia smithii

1972 ◽  
Vol 50 (6) ◽  
pp. 713-719 ◽  
Author(s):  
William E. Bradshaw ◽  
L. Philip Lounibos
Keyword(s):  
Larval Instar ◽  
Pitcher Plant ◽  
Photoperiodic Control ◽  
Wyeomyia Smithii ◽  
Diapause Termination ◽  
Environmental Consequences ◽  
The Third ◽  
Short Day ◽  
Critical Daylength ◽  
Short Days

Wyeomyia smithii diapause in the third larval instar. Long days avert or terminate and short days promote or maintain diapause. Diapause occurs early in the third instar and may be terminated by photoperiodic stimuli without the intervention of chilling or other factors. Fifty percent termination of diapause requires about 3 long days and another [Formula: see text] days are consumed in the third instar for postdiapause development. The critical daylength is identical for both the initiation and termination of diapause, 14.75 h of light per day. But, the photoperiodic clock monitoring diapause decisions is several times as accurate during initiation as in termination, reflecting the more drastic environmental consequences of development misdirection in the fall than in the spring. This accuracy is further enhanced by a prolongation of the second instar under short-day conditions. The doubling in the duration of the second instar exhibits the same critical daylength properties as diapause determination.The third instar is divisible into four distinct developmental periods: prediapause, diapause, termination of diapause, and postdiapause. Methods for quantifying these periods are presented. Similar manipulations could be employed for other diapausing arthropods, regardless of the stage at which dormancy occurs or the cues used in its regulation.

Biology of tree-hole mosquitoes: photoperiodic control of development in northern Toxorhynchites rutilus (Coq.)

1975 ◽  
Vol 53 (7) ◽  
pp. 889-893 ◽  
Author(s):  
William E. Bradshaw ◽  
Christina M. Holzapfel
Keyword(s):  
Rapid Growth ◽  
Fourth Instar ◽  
Photoperiodic Control ◽  
The Third ◽  
Winter Conditions ◽  
Tree Hole ◽  
Critical Photoperiod ◽  
Northern Portion ◽  
Toxorhynchites Rutilus ◽  
Short Days

Carnivorous larvae of the tree-hole mosquito, Toxorhynchites rutilus, were collected from the northern portion of their range. Long days were found to promote rapid growth and metamorphosis from egg to adult; short days retard development during the second and third instars and evoke diapause in the fourth. All larvae exposed continuously to long days from embryos to the third or fourth instar developed without entering diapause. Diapause-averting long days experienced earlier in development could be reversed in at least some individuals by subsequent short days. Among laboratory-reared larvae or those caught early in the fall, the critical photoperiod for the maintenance of diapause is around 13 h of light per day. Among larvae caught in midwinter, diapause is not maintained in all larvae at any photoperiod and in 50% or less of the larvae at photophases shorter than 12.5 h. Winter conditions in the northern part of the range of T. rutilus appear to play a prominent role in the maintenance and termination of diapause.

Photoperiodism in Orthopodomyia signifera

1973 ◽  
Vol 51 (3) ◽  
pp. 355-357 ◽  
Author(s):  
William E. Bradshaw
Keyword(s):  
North Carolina ◽  
Rapid Development ◽  
Larval Instar ◽  
Developmental Rate ◽  
Photoperiodic Response ◽  
The Third ◽  
Tree Hole ◽  
Fourth Larval Instar ◽  
Lower Temperature ◽  
Short Days

Larvae of the tree-hole mosquito, Orthopodomyia signifera, were collected from North Carolina and subjected to long- and short-day photoperiods. Long days at 25 °C permit rapid molting of fourth instar larvae to pupae. Lower temperature (15 °C) modifies developmental rate but does not appear to block photoperiodic response to long days. Short days at 25 °C may halt development, may retard development, or may permit rapid development in either the third or fourth larval instar. O. signifera is probably polymorphic for both the stage at which diapause may occur and for the depth or firmness with which it is established.

Long-Term Copper Toxicity on Scenedesmus quadricauda and Complexing Polypeptides

1995 ◽  
Vol 30 (2) ◽  
pp. 265-276 ◽  
Author(s):  
Denis Bussières ◽  
Raynald Côté ◽  
Clément Richard ◽  
Édith St-Pierre
Keyword(s):  
Heavy Metal ◽  
Sharp Increase ◽  
Copper Ions ◽  
Copper Toxicity ◽  
Scenedesmus Quadricauda ◽  
Continuous Exposure ◽  
Exponential Curve ◽  
Negative Exponential

Abstract Long-term copper toxicity has been demonstrated in Scenedesmus quadricauda. Upon continuous exposure to copper ions at 250 μg/L, the algae responded by a sharp increase in the synthesis of complexing polypeptides to chelate Cu. Complexing polypeptides gradually decreased, as observed by six sampling tests over 732 h, resembling to a negative exponential curve. This gradual diminution is considered to be a prime mechanism of acclimation or of adaptation to a heavy metal contaminated environment.

Laura’s Students One and Seven Years Later

2018 ◽  
Author(s):  
Marilyn Watson
Keyword(s):  
School District ◽  
Life Skills ◽  
Adopted Child ◽  
The Third

In the third year, Laura took a leave through November to help settle her newly adopted child. Her students missed her and, when she returned, some seemed to have reverted to their original untrusting selves. Soon, their trust in Laura and in themselves was restored. Would that trust remain? Seven years later, I interviewed 9 of the 14 students still in the school district. All remembered Laura and the class fondly. Eight had detailed memories of their interactions with Laura, and the life skills and attitudes they learned in her class. Of the six students who were judged insecurely attached when they entered Laura’s class, four appeared successful and confident and two were currently failing most of their courses. Possible causes for the long-term success of some students and failure of others are discussed.

GA: Armani’s Giorgio Armani

2018 ◽  
Author(s):  
Paul Brooker ◽  
Margaret Hayward
Keyword(s):  
Final Section ◽  
The Body ◽  
Body Shop ◽  
The Third ◽  
Haute Couture ◽  
Fashion Designer ◽  
The Body Shop ◽  
The Uk ◽  
Career Woman

The Armani high-fashion example illustrates the importance of adaptive rational methods in his founding and developing of an iconic high-fashion firm. Armani adapted stylistically to fashion’s new times in the 1970–80s by creating a new style catering for the career woman. His stylistic adaptation is compared with that of another famous Italian fashion designer, Versace, who instead modernized haute couture fashion and created a succession of glamourous styles. Both leaders exploited the same opportunity but in different ways. The third section compares these leaders’ legacies in the 1990s–2000s and assesses from a long-term perspective how capably they had used adaptive rational methods. The final section shifts the focus from fashion to the cosmetics industry and from Italy to the UK. Anita Roddick used adaptive rational methods to establish The Body Shop corporation in the 1970s–80s. However, she then abandoned rational methods with dire results for her corporation in the 1990s.

scholarly journals Extended analytical formulae for the perturbed Keplerian motion under low-thrust acceleration and orbital perturbations

2021 ◽  
Vol 133 (3) ◽  
Author(s):  
Marilena Di Carlo ◽  
Simão da Graça Marto ◽  
Massimiliano Vasile
Keyword(s):  
Gravitational Perturbation ◽  
Low Thrust ◽  
Orbital Elements ◽  
Third Body ◽  
The Third ◽  
Orbital Perturbations ◽  
Analytical Formulae ◽  
Numerical Orbit ◽  
Body Potential

AbstractThis paper presents a collection of analytical formulae that can be used in the long-term propagation of the motion of a spacecraft subject to low-thrust acceleration and orbital perturbations. The paper considers accelerations due to: a low-thrust profile following an inverse square law, gravity perturbations due to the central body gravity field and the third-body gravitational perturbation. The analytical formulae are expressed in terms of non-singular equinoctial elements. The formulae for the third-body gravitational perturbation have been obtained starting from equations for the third-body potential already available in the literature. However, the final analytical formulae for the variation of the equinoctial orbital elements are a novel derivation. The results are validated, for different orbital regimes, using high-precision numerical orbit propagators.

scholarly journals Cost-effectiveness of a hybrid emergency room system for severe trauma: a health technology assessment from the perspective of the third-party payer in Japan

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Takahiro Kinoshita ◽  
Kensuke Moriwaki ◽  
Nao Hanaki ◽  
Tetsuhisa Kitamura ◽  
Kazuma Yamakawa ◽  
...  
Keyword(s):  
Cost Effectiveness ◽  
Emergency Room ◽  
Healthcare Costs ◽  
Cost Effective ◽  
Severe Trauma ◽  
Third Party ◽  
Trauma Patients ◽  
Short Term ◽  
The Third

Abstract Background Hybrid emergency room (ER) systems, consisting of an angiography-computed tomography (CT) machine in a trauma resuscitation room, are reported to be effective for reducing death from exsanguination in trauma patients. We aimed to investigate the cost-effectiveness of a hybrid ER system in severe trauma patients without severe traumatic brain injury (TBI). Methods We conducted a cost-utility analysis comparing the hybrid ER system to the conventional ER system from the perspective of the third-party healthcare payer in Japan. A short-term decision tree and a long-term Markov model using a lifetime time horizon were constructed to estimate quality-adjusted life years (QALYs) and associated lifetime healthcare costs. Short-term mortality and healthcare costs were derived from medical records and claims data in a tertiary care hospital with a hybrid ER. Long-term mortality and utilities were extrapolated from the literature. The willingness-to-pay threshold was set at $47,619 per QALY gained and the discount rate was 2%. Deterministic and probabilistic sensitivity analyses were conducted. Results The hybrid ER system was associated with a gain of 1.03 QALYs and an increment of $33,591 lifetime costs compared to the conventional ER system, resulting in an ICER of $32,522 per QALY gained. The ICER was lower than the willingness-to-pay threshold if the odds ratio of 28-day mortality was < 0.66. Probabilistic sensitivity analysis indicated that the hybrid ER system was cost-effective with a 79.3% probability. Conclusion The present study suggested that the hybrid ER system is a likely cost-effective strategy for treating severe trauma patients without severe TBI.

scholarly journals Dominance relationships and coalitionary aggression against conspecifics in female carrion crows

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Benedikt Holtmann ◽  
Julia Buskas ◽  
Matthew Steele ◽  
Kristaps Solokovskis ◽  
Jochen B. W. Wolf
Keyword(s):  
Social Interactions ◽  
Social Environment ◽  
Social Rank ◽  
Social Benefits ◽  
Same Sex ◽  
The Third ◽  
Dominance Relationships ◽  
Dominant Individual ◽  
The Individual

Abstract Cooperation is a prevailing feature of many animal systems. Coalitionary aggression, where a group of individuals engages in coordinated behaviour to the detriment of conspecific targets, is a form of cooperation involving complex social interactions. To date, evidence has been dominated by studies in humans and other primates with a clear bias towards studies of male-male coalitions. We here characterize coalitionary aggression behaviour in a group of female carrion crows consisting of recruitment, coordinated chase, and attack. The individual of highest social rank liaised with the second most dominant individual to engage in coordinated chase and attack of a lower ranked crow on several occasions. Despite active intervention by the third most highly ranked individual opposing the offenders, the attack finally resulted in the death of the victim. All individuals were unrelated, of the same sex, and naïve to the behaviour excluding kinship, reproduction, and social learning as possible drivers. Instead, the coalition may reflect a strategy of the dominant individual to secure long-term social benefits. Overall, the study provides evidence that members of the crow family engage in coordinated alliances directed against conspecifics as a possible means to manipulate their social environment.

scholarly journals A Regime View of the North Atlantic Oscillation and Its Response to Anthropogenic Forcing

2010 ◽  
Vol 23 (6) ◽  
pp. 1291-1307 ◽  
Author(s):  
Tim Woollings ◽  
Abdel Hannachi ◽  
Brian Hoskins ◽  
Andrew Turner
Keyword(s):  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Anthropogenic Forcing ◽  
The Third ◽  
The North ◽  
Nao Index ◽  
Future Behavior ◽  
Real Change ◽  
The North Atlantic Oscillation

Abstract The distribution of the daily wintertime North Atlantic Oscillation (NAO) index in the 40-yr ECMWF Re-Analysis (ERA-40) is significantly negatively skewed. Dynamical and statistical analyses both suggest that this skewness reflects the presence of two distinct regimes—referred to as “Greenland blocking” and “subpolar jet.” Changes in both the relative occurrence and in the structure of the regimes are shown to contribute to the long-term NAO trend over the ERA-40 period. This is contrasted with the simulation of the NAO in 100-yr control and doubled CO2 integrations of the third climate configuration of the Met Office Unified Model (HadCM3). The model has clear deficiencies in its simulation of the NAO in the control run, so its predictions of future behavior must be treated with caution. However, the subpolar jet regime does become more dominant under anthropogenic forcing and, while this change is small it is clearly statistically significant and does represent a real change in the nature of NAO variability in the model.

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