specific timing
Recently Published Documents


TOTAL DOCUMENTS

59
(FIVE YEARS 12)

H-INDEX

14
(FIVE YEARS 1)

2021 ◽  
Vol 76 (1) ◽  
Author(s):  
Linus Hedh ◽  
Juliana Dänhardt ◽  
Anders Hedenström

Abstract A common migratory pattern in birds is that northerly breeding populations migrate to more southerly non-breeding sites compared to southerly breeding populations (leap-frog migration). Not only do populations experience differences in migration distances, but also different environmental conditions, which may vary spatiotemporally within their annual cycles, creating distinctive selective pressures and migratory strategies. Information about such adaptations is important to understand migratory drivers and evolution of migration patterns. We use light-level geolocators and citizen science data on regional spring arrivals to compare two populations of common ringed plover Charadrius hiaticula breeding at different latitudes. We (1) describe and characterize the annual cycles and (2) test predictions regarding speed and timing of migration. The northern breeding population (NBP) wintered in Africa and the southern (SBP) mainly in Europe. The annual cycles were shifted temporally so that the NBP was always later in all stages. The SBP spent more than twice as long time in the breeding area, but there was no difference in winter. The NBP spent more time on migration in general. Spring migration speed was lower in the SBP compared to autumn speed of both populations, and there was no difference in autumn and spring speed in the NBP. We also found a larger variation in spring arrival times across years in the SBP. This suggests that a complex interaction of population specific timing and variation of breeding onset, length of breeding season, and proximity to the breeding area shape the annual cycle and migratory strategies. Significance statement Migration distance, climate, and the resulting composition of the annual cycle are expected to influence migration strategies and timing in birds. Testing theories regarding migration behaviours are challenging, and intraspecific comparisons over the full annual cycle are still rare. Here we compare the spatiotemporal distributions of two latitudinally separated populations of common ringed plovers using light-level geolocators. We found that there was a larger long-term variation in first arrival dates and that migration speed was slower only in spring in a temperate, short-distance migratory population, compared to an Arctic, long-distance migratory population. This suggests that a complex interaction of population specific timing and variation of breeding onset, length of breeding season and proximity to the breeding area shape the annual cycle and migratory behaviours.


Author(s):  
Patricia Brandes ◽  
◽  
Brian Pyper ◽  
Michael Banks ◽  
David Jacobsen ◽  
...  

There are four distinct runs of Chinook Salmon (Oncorhynchus tshawytscha) in the Central Valley, named after their primary adult return times: fall, late-fall, winter, and spring run. Estimating the run-specific composition of juveniles entering and leaving the Sacramento–San Joaquin Delta is crucial for assessing population status and processes that affect juvenile survival through the Delta. Historically, the run of juvenile Chinook Salmon captured in the field has been determined using a length-at-date criteria (LDC); however, LDC run assignments may be inaccurate if there is high overlap in the run-specific timing and size of juveniles entering and leaving the Delta. In this study, we use genetic run assignments to assess the accuracy of LDC at two trawl locations in the Sacramento River (Delta entry) and at Chipps Island (Delta exit). Fin tissues were collected from approximately 7,500 juvenile Chinook Salmon captured in trawl samples between 2007 and 2011. Tissues were analyzed using 21 microsatellites to determine genetic run assignments for individuals, which we compared with LDC run assignments. Across years, there was extensive overlap among the distributions of run-specific fork lengths of genetically identified juveniles, indicating that run compositions based on LDC assignments would tend to underestimate fall-run and especially late-fall-run compositions at both trawl locations, and greatly overestimate spring-run compositions (both locations) and winter-run compositions (Chipps Island). We therefore strongly support ongoing efforts to include tissue sampling and genetic run identification of juvenile Chinook Salmon at key monitoring locations in the Sacramento–San Joaquin River system.


Zygote ◽  
2021 ◽  
pp. 1-7
Author(s):  
R.A. Alih ◽  
S.G. Solomon ◽  
S.O. Olufeagba ◽  
J.O. Cheikyula ◽  
A.B. Abol-Munafi ◽  
...  

Summary The study sought to investigate the chronology of events and timing of embryogenesis, as well as breeding performances of three strains of Heterobranchus longifilis from Nigeria. Fish samples were collected from Benue River in Makurdi, Niger River in Onitsha, and Rima River in Sokoto for this study. Induced spawning of the strains was carried out so that egg development could be tracked from fertilization to hatching using a simple microscope. The microphotographs obtained showed that the embryogenesis of the strains followed a similar pattern to those of other members of the family Clariidae, however with changes occurring in the specific timing of the sequences of events (i.e. interstrain and interspecies differences). When the different strains were compared, the study noted similarities (P > 0.05) in the overall breeding performance (except for fertilization rate), survival at different stages of development, timing of embryogenesis, and larvae characteristics. The outcomes of this study, therefore, provide baseline information on what genetic improvement of the species through strain crossing can be attempted in future studies.


Author(s):  
Guglielmo Maria Caporale ◽  
Alex Plastun

AbstractThis paper explores price (momentum and contrarian) effects and their timing parameters on the days characterised by abnormal returns and the following ones in two commodity markets. Specifically, using daily gold and oil price data over the period 01.01.2009–31.03.2020 the following hypotheses are tested: (H1) there is a time gap between the detection of an abnormal return day and the end of that day, (H2) there are price effects on the day after abnormal returns occur; (H3) price effects after 1-day abnormal returns have identifiable timing parameters; (H4) the detected timing parameters can be used to “beat the market”. For these purposes average analysis, t tests, CAR and trading simulation approaches are used. The main results can be summarised as follows. Prices tend to move in the direction of abnormal returns till the end of the day when these occur. The presence of abnormal returns can usually be detected before the end of the day by estimating specific timing parameters, and a momentum effect can be detected. On the following day two different price patterns are detected: a momentum effect for oil prices and a contrarian effect for gold prices, respectively. These effects are limited in time, and the corresponding timing parameters are estimated. Trading simulations show that these effects can be exploited to generate abnormal profits with an appropriate calibration of the timing parameters.


2020 ◽  
Vol 49 (5) ◽  
pp. E17
Author(s):  
Daniel Rafter ◽  
Ranveer Vasdev ◽  
Duncan Hurrelbrink ◽  
Mark Gormley ◽  
Tabitha Chettupally ◽  
...  

OBJECTIVECurrent guidelines do not specify timing for management of acute spinal cord injury (aSCI) due to lack of high-quality evidence supporting specific intervals for intervention. Randomized prospective trials may be unethical. Nonetheless, physicians have been sued for delays in diagnosis and intervention.METHODSThe authors reviewed both the medical literature supporting the guidelines and the legal cases reported in the Westlaw and Lexis Advance databases from 1972 to 2018 resulting in awards or settlements, to identify whether surgeons are vulnerable to litigation despite the existence of guidelines not mandating specific timing of care.RESULTSTiming of intervention was related to claims in 59 (36%) of 163 cases involving SCI. All 22 trauma cases identified cited timing of intervention, sometimes related to delayed diagnosis, as a reason for the lawsuit. The mean award of 10 cases in which the plaintiffs’ awards were disclosed was $4,294,384. In the majority of cases, award amounts were not disclosed.CONCLUSIONSBecause conduct of a prospective, randomized trial to investigate surgical timing of intervention for aSCI may not be achievable, evidence-based guidelines will be unlikely to mandate specific timing. Nonetheless, surgeons who unreasonably delay intervention for aSCI may be at risk for litigation due to treatment delay. This is increasingly likely in an environment where “complete” SCI is difficult to verify. SCI may at some point be recognized as a surgical emergency, as brain injury generally is, despite a lack of prospective randomized trials supporting this implementation, challenging the feasibility of the US trauma infrastructure to provide care for these patients.


2020 ◽  
Vol 15 (4) ◽  
pp. 241-249
Author(s):  
Alissa Lenz, BS ◽  
Ryan Shelton, MPS, NREMT-P ◽  
Rebecca Ryznar, PhD ◽  
Kit Lavell, BA ◽  
David Ross, DO, FACEP ◽  
...  

Objective: As the incidence of active shooters increase, local emergency response has also changed. South Metro Fire Rescue coordinated a series of hyper-realistic active shooter simulation drills involving multiple agencies.Methods: “The Next Nine Minutes” was one of the largest active shooter drills performed to date with 904 personnel that were trained in 18 mass casualty active shooter drills. Evaluation was from point of injury to and including care in the operating room (OR), and evaluation of real-time system logistics.Results: A total of 126 patients in Cut Suits® received a total of 479 procedures such as needle decompressions, cricothyrotomies, tourniquets, wound packs, and chest tubes. Central to this exercise, law enforcement (LE) established a warm zone from the initial shooting. EMS was able to move into the facility, locate casualties, extract the first victim, move them to a casualty collection point (CCP), and transport them to safety within 12 minutes.Conclusions: Strengths and weaknesses were identified in prehospital and in-hospital care. These included what roles agencies play in a true event, specific timing in establishing areas such as the warm zone and CCP, transportation, and logistics at the accepting hospitals. Only after the barriers to success were identified and addressed did the timing of casualty movement drastically improve. Lessons learned from this training were ultimately used to save lives at the STEM School, Highlands Ranch, and Colorado Shooting. This in situ immersion training should be practiced as a whole system.


Author(s):  
Fabio Landini ◽  
Rasmus Lema ◽  
Franco Malerba

Abstract This article examines the role played by demand in catching up and in leadership changes in green industries, motivated by the belief that demand-led catch-up is a prevalent pathway in such industries. The article first examines stylized cases of sectoral green catch-up by China in which the local market and domestic demand played an important role before the sector started expanding globally. In particular, the focus is on three industries: wind, biomass and hydropower. Then, it uses a history-friendly model to study the effects of a major increase in domestic demand (a “demand window”) in a green industry. The baseline simulation first examines the effects of a demand window in promoting learning and capability building by latecomers and in triggering a catch-up process. Then, the counterfactual simulations show that (i) a technological discontinuity which takes place after the demand window could reduce the effectiveness of the demand window in the catch-up process; (ii) the specific timing of the demand window could significantly alter the dynamic patterns of catch-up; (iii) protectionism is a necessary condition for the demand window to have its effect; and (iv) regimes of slow capability accumulation could turn out to be beneficial for the latecomer when a technological discontinuity follows the demand window. These results can help policymakers in identifying key conditions related to demand-led catch-up strategies.


2020 ◽  
pp. 135910532093705 ◽  
Author(s):  
Sara D McMullin ◽  
Grant S Shields ◽  
George M Slavich ◽  
Tony W Buchanan

The study investigated whether lifetime stress exposure is associated with greater impulsivity and addictive behavior. We also examined whether stress and impulsivity interactively predicted food addiction and alcohol-related behavior. Greater lifetime stress exposure was related to more impulsivity and food addictive behaviors, but not alcohol-related consequences. There were no interactions between lifetime stress exposure and impulsivity in predicting addictive behaviors. Exploratory analyses revealed that early and adulthood stress exposure predicted food addiction, whereas only adulthood stress predicted alcohol-related consequences. Therefore, lifetime stress exposure is related to impulsivity and addiction, but these effects differ by addiction outcome and specific timing of stress exposure.


2020 ◽  
Vol 34 (09) ◽  
pp. 2050083
Author(s):  
Hui Liu ◽  
Hang Liu ◽  
Cheryl Ford

A potential scheme to obtain intense harmonic spectra from X[Formula: see text] ([Formula: see text] and T) has been studied by using chirped-delay effect and half-cycle pulse. First, for the shorter pulse duration case, the main contributions of harmonic spectra of H[Formula: see text] and T[Formula: see text] are both coming from the falling part of laser field. While, for the longer pulse duration case, the rising and falling parts of laser field play the main role in harmonic spectra of H[Formula: see text] and T[Formula: see text], respectively. Second, according to the changed law of harmonic yields of H[Formula: see text] and T[Formula: see text] and by properly introducing the chirp-delay effect at some specific timing, the intense harmonic emission peak (HEP) can be obtained from both H[Formula: see text] and T[Formula: see text]. Third, with the help of the half-cycle pulse, the selected HEP can be further extended, showing the intense and broad spectral continua. Finally, by Fourier transformation of some harmonics on the spectral continua, the intense attosecond pulses with durations of 35 as can be produced.


2020 ◽  
Vol 30 (8) ◽  
pp. 4381-4401 ◽  
Author(s):  
Alexandre Mendes ◽  
Gaetan Vignoud ◽  
Sylvie Perez ◽  
Elodie Perrin ◽  
Jonathan Touboul ◽  
...  

Abstract The striatum integrates inputs from the cortex and thalamus, which display concomitant or sequential activity. The striatum assists in forming memory, with acquisition of the behavioral repertoire being associated with corticostriatal (CS) plasticity. The literature has mainly focused on that CS plasticity, and little remains known about thalamostriatal (TS) plasticity rules or CS and TS plasticity interactions. We undertook here the study of these plasticity rules. We found bidirectional Hebbian and anti-Hebbian spike-timing-dependent plasticity (STDP) at the thalamic and cortical inputs, respectively, which were driving concurrent changes at the striatal synapses. Moreover, TS- and CS-STDP induced heterosynaptic plasticity. We developed a calcium-based mathematical model of the coupled TS and CS plasticity, and simulations predict complex changes in the CS and TS plasticity maps depending on the precise cortex–thalamus–striatum engram. These predictions were experimentally validated using triplet-based STDP stimulations, which revealed the significant remodeling of the CS-STDP map upon TS activity, which is notably the induction of the LTD areas in the CS-STDP for specific timing regimes. TS-STDP exerts a greater influence on CS plasticity than CS-STDP on TS plasticity. These findings highlight the major impact of precise timing in cortical and thalamic activity for the memory engram of striatal synapses.


Sign in / Sign up

Export Citation Format

Share Document