scholarly journals Collective mechanical adaptation of honeybee swarms

2017 ◽  
Author(s):  
O. Peleg ◽  
J.M. Peters ◽  
M.K. Salcedo ◽  
L. Mahadevan
Keyword(s):  
Apis Mellifera ◽  
Mechanical Loading ◽  
Behavioral Response ◽  
Total Duration ◽  
Mechanical Adaptation ◽  
Dynamic Stimuli ◽  
Single Organism ◽  
Before And After ◽  
The Individual ◽  
Dynamic Loading Conditions

Honeybee Apis mellifera swarms form clusters made solely of bees attached to each other, forming pendant structures on tree branches (1). These clusters can be hundreds of times the size of a single organism. How these structures are stably maintained under the influence of static gravity and dynamic stimuli (e.g. wind) is unknown. To address this, we created pendant conical clusters attached to a board that was shaken with varying amplitude, frequency and total duration. Our observations show that horizontally shaken clusters spread out to form wider, flatter cones, i.e. the cluster adapts to the dynamic loading conditions, but in a reversible manner - when the loading is removed, the cluster recovers its original shape, slowly. Measuring the response of a cluster to a sharp pendular excitation before and after it adapted shows that the flattened cones deform less and relax faster than the elongated ones, i.e. they are more stable mechanically. We use particle-based simulations of a passive assemblage to suggest a behavioral hypothesis that individual bees respond to local variations in strain. This behavioral response improves the collective stability of the cluster as a whole at the expense of increasing the average mechanical burden experienced by the individual. Simulations using this rule explain our observations of adaptation to horizontal shaking. The simulations also suggest that vertical shaking will not lead to significant differential strains and thus no adaptation. To test this, we shake the cluster vertically and find that indeed there is no response to this stimulus. Altogether, our results show how an active, functional super–organism structure can respond adaptively to dynamic mechanical loading by changing its morphology to achieve better load sharing.

Official Advice Improves Mortgage-Holders’ Perceptions of Switching: Experimental Evidence

2019 ◽  
Author(s):  
Shane Timmons
Keyword(s):  
Interest Rate ◽  
Experimental Evidence ◽  
Consumer Protection ◽  
Policy Development ◽  
Switching Process ◽  
Competitive Markets ◽  
Protection Agency ◽  
Change Perceptions ◽  
Before And After ◽  
The Individual

Encouraging consumers to switch to lower-rate mortgages is important both for the individual consumer’s finances and for functioning competitive markets, but switching rates are low. Given the complexity of mortgages, one potential regulatory intervention that may increase switching rates is to provide independent advice on how to select good mortgage products and how to navigate the switching process. Working with a government consumer protection agency, we conducted an experiment with mortgage-holders to test whether such advice alters perceptions of switching. The experiment tested how (i) the attributes of the offer, (ii) perceptions about the switching process, (iii) individual feelings of competence and (iv) comprehension of the product affect willingness to switch to better offers, both before and after reading the official advice. The advice made consumers more sensitive to interest rate decreases, especially at longer terms. It also increased consumers’ confidence in their ability to select good offers. Overall, the findings imply that advice from policymakers can change perceptions and increase switching rates. Moreover, the experiment demonstrates how lab studies can contribute to behaviourally-informed policy development.

Quality of Life for Children with Persistent Sinonasal Symptoms

2003 ◽  
Vol 128 (1) ◽  
pp. 17-26 ◽  
Author(s):  
David J. Kay ◽  
Richard M. Rosenfeld
Keyword(s):  
Quality Of Life ◽  
Clinical Care ◽  
Longitudinal Change ◽  
Good Test ◽  
Routine Clinical Care ◽  
Before And After ◽  
The Mean ◽  
The Individual ◽  
Sinonasal Symptoms

OBJECTIVE: The goal was to validate the SN-5 survey as a measure of longitudinal change in health-related quality of life (HRQoL) for children with persistent sinonasal symptoms. DESIGN AND SETTING: We conducted a before and after study of 85 children aged 2 to 12 years in a metropolitan pediatric otolaryngology practice. Caregivers completed the SN-5 survey at entry and at least 4 weeks later. The survey included 5 symptom-cluster items covering the domains of sinus infection, nasal obstruction, allergy symptoms, emotional distress, and activity limitations. RESULTS: Good test-retest reliability ( R = 0.70) was obtained for the overall SN-5 score and the individual survey items ( R ≥ 0.58). The mean baseline SN-5 score was 3.8 (SD, 1.0) of a maximum of 7.0, with higher scores indicating poorer HRQoL. All SN-5 items had adequate correlation ( R ≥ 0.36) with external constructs. The mean change in SN-5 score after routine clinical care was 0.88 (SD, 1.19) with an effect size of 0.74 indicating good responsiveness to longitudinal change. The change scores correlated appropriately with changes in related external constructs ( R ≥ 0.42). CONCLUSIONS: The SN-5 is a valid, reliable, and responsive measure of HRQoL for children with persistent sinonasal symptoms, suitable for use in outcomes studies and routine clinical care.

scholarly journals General psychopathology links burden of recent life events and psychotic symptoms in a network approach

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Linda T. Betz ◽  
◽  
Nora Penzel ◽  
Lana Kambeitz-Ilankovic ◽  
Marlene Rosen ◽  
...  
Keyword(s):  
Life Events ◽  
Childhood Trauma ◽  
Negative Symptoms ◽  
Psychotic Symptoms ◽  
Network Approach ◽  
General Psychopathology ◽  
Recent Onset ◽  
Syndrome Scale ◽  
Before And After ◽  
The Individual

AbstractRecent life events have been implicated in the onset and progression of psychosis. However, psychological processes that account for the association are yet to be fully understood. Using a network approach, we aimed to identify pathways linking recent life events and symptoms observed in psychosis. Based on previous literature, we hypothesized that general symptoms would mediate between recent life events and psychotic symptoms. We analyzed baseline data of patients at clinical high risk for psychosis and with recent-onset psychosis (n = 547) from the Personalised Prognostic Tools for Early Psychosis Management (PRONIA) study. In a network analysis, we modeled links between the burden of recent life events and all individual symptoms of the Positive and Negative Syndrome Scale before and after controlling for childhood trauma. To investigate the longitudinal associations between burden of recent life events and symptoms, we analyzed multiwave panel data from seven timepoints up to month 18. Corroborating our hypothesis, burden of recent life events was connected to positive and negative symptoms through general psychopathology, specifically depression, guilt feelings, anxiety and tension, even after controlling for childhood trauma. Longitudinal modeling indicated that on average, burden of recent life events preceded general psychopathology in the individual. In line with the theory of an affective pathway to psychosis, recent life events may lead to psychotic symptoms via heightened emotional distress. Life events may be one driving force of unspecific, general psychopathology described as characteristic of early phases of the psychosis spectrum, offering promising avenues for interventions.

Adaptive Precision Block-Jacobi for High Performance Preconditioning in the Ginkgo Linear Algebra Software

2021 ◽  
Vol 47 (2) ◽  
pp. 1-28
Author(s):  
Goran Flegar ◽  
Hartwig Anzt ◽  
Terry Cojean ◽  
Enrique S. Quintana-Ortí
Keyword(s):  
Linear Algebra ◽  
Graphics Processing Units ◽  
High Performance ◽  
Numerical Algorithms ◽  
Mixed Precision ◽  
Before And After ◽  
Memory Accesses ◽  
Specialized Hardware ◽  
The Individual ◽  
Graphics Processing

The use of mixed precision in numerical algorithms is a promising strategy for accelerating scientific applications. In particular, the adoption of specialized hardware and data formats for low-precision arithmetic in high-end GPUs (graphics processing units) has motivated numerous efforts aiming at carefully reducing the working precision in order to speed up the computations. For algorithms whose performance is bound by the memory bandwidth, the idea of compressing its data before (and after) memory accesses has received considerable attention. One idea is to store an approximate operator–like a preconditioner–in lower than working precision hopefully without impacting the algorithm output. We realize the first high-performance implementation of an adaptive precision block-Jacobi preconditioner which selects the precision format used to store the preconditioner data on-the-fly, taking into account the numerical properties of the individual preconditioner blocks. We implement the adaptive block-Jacobi preconditioner as production-ready functionality in the Ginkgo linear algebra library, considering not only the precision formats that are part of the IEEE standard, but also customized formats which optimize the length of the exponent and significand to the characteristics of the preconditioner blocks. Experiments run on a state-of-the-art GPU accelerator show that our implementation offers attractive runtime savings.

scholarly journals Micromagnetic Characterization of Operation-Induced Damage in Charpy Specimens of RPV Steels

2021 ◽  
Vol 11 (7) ◽  
pp. 2917
Author(s):  
Madalina Rabung ◽  
Melanie Kopp ◽  
Antal Gasparics ◽  
Gábor Vértesy ◽  
Ildikó Szenthe ◽  
...  
Keyword(s):  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Operating Conditions ◽  
Magnetic Characteristics ◽  
Pressure Vessel Steel ◽  
Training Procedure ◽  
Vessel Steel ◽  
Before And After ◽  
The Individual ◽  
Magnetic Adaptive Testing

The embrittlement of two types of nuclear pressure vessel steel, 15Kh2NMFA and A508 Cl.2, was studied using two different methods of magnetic nondestructive testing: micromagnetic multiparameter microstructure and stress analysis (3MA-X8) and magnetic adaptive testing (MAT). The microstructure and mechanical properties of reactor pressure vessel (RPV) materials are modified due to neutron irradiation; this material degradation can be characterized using magnetic methods. For the first time, the progressive change in material properties due to neutron irradiation was investigated on the same specimens, before and after neutron irradiation. A correlation was found between magnetic characteristics and neutron-irradiation-induced damage, regardless of the type of material or the applied measurement technique. The results of the individual micromagnetic measurements proved their suitability for characterizing the degradation of RPV steel caused by simulated operating conditions. A calibration/training procedure was applied on the merged outcome of both testing methods, producing excellent results in predicting transition temperature, yield strength, and mechanical hardness for both materials.

scholarly journals Intra-Colonial Viral Infections in Western Honey Bees (Apis mellifera)

2021 ◽  
Vol 9 (5) ◽  
pp. 1087
Author(s):  
Loreley Castelli ◽  
María Laura Genchi García ◽  
Anne Dalmon ◽  
Daniela Arredondo ◽  
Karina Antúnez ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Viral Infections ◽  
Sampling Period ◽  
Virus Genome ◽  
The Individual ◽  
Bee Virus ◽  
Insight Into ◽  
Bee Viruses

RNA viruses play a significant role in the current high losses of pollinators. Although many studies have focused on the epidemiology of western honey bee (Apis mellifera) viruses at the colony level, the dynamics of virus infection within colonies remains poorly explored. In this study, the two main variants of the ubiquitous honey bee virus DWV as well as three major honey bee viruses (SBV, ABPV and BQCV) were analyzed from Varroa-destructor-parasitized pupae. More precisely, RT-qPCR was used to quantify and compare virus genome copies across honey bee pupae at the individual and subfamily levels (i.e., patrilines, sharing the same mother queen but with different drones as fathers). Additionally, virus genome copies were compared in cells parasitized by reproducing and non-reproducing mite foundresses to assess the role of this vector. Only DWV was detected in the samples, and the two variants of this virus significantly differed when comparing the sampling period, colonies and patrilines. Moreover, DWV-A and DWV-B exhibited different infection patterns, reflecting contrasting dynamics. Altogether, these results provide new insight into honey bee diseases and stress the need for more studies about the mechanisms of intra-colonial disease variation in social insects.

Acquiring variable commands at home and abroad: Examining optatives and imperatives in L1 and L2 Spanish

2020 ◽  
Vol 13 (1) ◽  
pp. 79-113
Author(s):  
Farrah Neumann ◽  
Matthew Kanwit
Keyword(s):  
Second Language ◽  
Second Language Acquisition ◽  
Study Abroad ◽  
Language Teaching ◽  
Applied Linguistics ◽  
Future Research ◽  
Control Group ◽  
Before And After ◽  
The Individual ◽  
At Home

AbstractSince many linguistic structures are variable (i. e. conveyed by multiple forms), building a second-language grammar critically involves developing sociolinguistic competence (Canale and Swain. 1980. Theoretical bases of communicative approaches to second language teaching and testing. Applied Linguistics 1(1). 1–47), including knowledge of contexts in which to use one form over another (Bayley and Langman. 2004. Variation in the group and the individual: Evidence from second language acquisition. International Review of Applied Linguistics in Language Teaching 42(4). 303–318). Consequently, researchers interested in such competence have increasingly analyzed the study-abroad context to gauge learners’ ability to approximate local norms following a stay abroad, due to the quality and quantity of input to which learners may gain access (Lafford. 2006. The effects of study abroad vs. classroom contexts on Spanish SLA: Old assumptions, new insights and future research directions. In Carol Klee & Timothy Face (eds.), Selected proceedings of the 7th conference on the acquisition of Spanish and Portuguese as first and second languages, 1–25. Somerville, MA: Cascadilla Proceedings Project). Nevertheless, the present study is the first to examine native or learner variation between imperative (e. g. ven ‘come’) and optative Spanish commands (e. g. que vengas ‘come’). We first performed a corpus analysis to determine the linguistic factors to manipulate in a contextualized task, which elicited commands from learners before and after four weeks abroad in Alcalá de Henares, Spain. Their overall rates of selection and predictive factors were compared to local native speakers (NSs) and a control group of at-home learners.Results revealed that the abroad learners more closely approached NS rates of selection following the stay abroad. Nonetheless, for both learner groups conditioning by independent variables only partially approximated the NS system, which was more complex than previously suggested.

Missing Data in Research on Youth and Family Programs

2021 ◽  
pp. 003329412110268
Author(s):  
Jaime Ballard ◽  
Adeya Richmond ◽  
Suzanne van den Hoogenhof ◽  
Lynne Borden ◽  
Daniel Francis Perkins
Keyword(s):  
Missing Data ◽  
Statistical Methods ◽  
Self Report ◽  
Program Participation ◽  
Multilevel Data ◽  
Individual Level ◽  
Level Data ◽  
Before And After ◽  
Post Test ◽  
The Individual

Background Multilevel data can be missing at the individual level or at a nested level, such as family, classroom, or program site. Increased knowledge of higher-level missing data is necessary to develop evaluation design and statistical methods to address it. Methods Participants included 9,514 individuals participating in 47 youth and family programs nationwide who completed multiple self-report measures before and after program participation. Data were marked as missing or not missing at the item, scale, and wave levels for both individuals and program sites. Results Site-level missing data represented a substantial portion of missing data, ranging from 0–46% of missing data at pre-test and 35–71% of missing data at post-test. Youth were the most likely to be missing data, although site-level data did not differ by the age of participants served. In this dataset youth had the most surveys to complete, so their missing data could be due to survey fatigue. Conclusions Much of the missing data for individuals can be explained by the site not administering those questions or scales. These results suggest a need for statistical methods that account for site-level missing data, and for research design methods to reduce the prevalence of site-level missing data or reduce its impact. Researchers can generate buy-in with sites during the community collaboration stage, assessing problematic items for revision or removal and need for ongoing site support, particularly at post-test. We recommend that researchers conducting multilevel data report the amount and mechanism of missing data at each level.

scholarly journals Discoloration of Historical Plastic Objects: New Insight into the Degradation of β-Naphthol Pigment Lakes

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2278
Author(s):  
Anna Micheluz ◽  
Eva Mariasole Angelin ◽  
João Almeida Lopes ◽  
Maria João Melo ◽  
Marisa Pamplona
Keyword(s):  
Light Exposure ◽  
Molecular Structures ◽  
Conservation Science ◽  
Organic Pigment ◽  
Organic Pigments ◽  
Before And After ◽  
The Individual ◽  
Determining Factor ◽  
Insight Into ◽  
Historical Samples

Light is a determining factor in the discoloration of plastics, and photodegradation processes can affect the molecular structures of both the polymer and colorants. Limited studies focused on the discoloration of heritage plastics in conservation science. This work investigated the discoloration of red historical polyethylene (PE) objects colored with PR 48:2 and PR 53:1. High-density and low-density PE reference polymers, neat pigment powders, and historical samples were assessed before and after accelerated photoaging. The applied methodology provided insight into the individual light-susceptibility of polyethylenes, organic pigment lakes, and their combined effect in the photoaging of historical plastic formulations. After light exposure, both PE references and historical samples yellowed, PR53:1 faded, and PR 48:2 darkened; however, both organic pigments faded severely in the historical samples. This highlights the role played by the plastic binder likely facilitating the pigment photofading. Fourier transform infrared spectroscopy and mass spectrometry techniques—EGA-MS, PY-GC/MS, and TD-GC/MS—were successfully employed for characterizing the plastic formulations and degradation. The identification of phthalic compounds in both aged β-naphthol powders opens new venues for studies on their degradation. This work’s approach and analytical methods in studying the discoloration of historical plastics are novel, proving their efficacy, reliability, and potentiality.

scholarly journals Simulation of Compressor Performance Deterioration due to Erosion

1989 ◽  
Author(s):  
W. Tabakoff ◽  
A. N. Lakshminarasimha ◽  
M. Pasin
Keyword(s):  
Fault Model ◽  
Experimental Results ◽  
Performance Tests ◽  
Individual Stage ◽  
One Stage ◽  
Before And After ◽  
Performance Deterioration ◽  
Compressor Performance ◽  
Multistage Compressor ◽  
The Individual

Experimental results obtained from cascades and one stage compressor performance tests before and after erosion were used to test a fault model to represent erosion. This model was implemented on a stage stacking program developed to demonstrate the effect of erosion in a multistage compressor. The effect of the individual stage erosion on the overall compressor performance is also demonstrated.

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