scholarly journals Short-Term Dynamics Reveals Seasonality in a Subtropical Heliconius Butterfly

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Thadeu Sobral-Souza ◽  
Ronaldo Bastos Francini ◽  
Murilo Guimarães ◽  
Woodruff Withman Benson

Although tropical insect populations are generally regarded as constant and stable over time, some of these tropical populations, including butterflies, may fluctuate according to precipitation and temperature variation, specialized feeding patterns, and density-dependent factors. Heliconiini butterfly populations are generally regarded as stable over time because of the presence of host-plants and absence of diapause. However, peaks of abundance occur in subtropical Heliconius populations, and opposite trends concerning stability are found in the literature. Here we further investigate the dynamics of subtropical Heliconius butterflies by assessing a population of the species Heliconius sara apseudes from southeastern Brazil. We estimated individual apparent survival probability and population growth rate while accounting for the imperfect detectability of individuals using mark-recapture models to evaluate the population dynamics. Adult males presented slightly higher weekly survival estimates than females. Contrary to the common pattern described in the literature for Heliconius populations we observed a rapid decline on the adult population by the end of the mating season, possibly leading to local extinction. We discuss the potential drivers for such dynamics.

2018 ◽  
Vol 47 (6) ◽  
pp. 1547-1552 ◽  
Author(s):  
Robert F Mitchell ◽  
Ann M Ray ◽  
Lawrence M Hanks ◽  
Jocelyn G Millar

Abstract We report here the pheromone of Megacyllene antennata (White) (Coleoptera: Cerambycidae), a species native to southwestern North America whose larvae feed in woody tissues of mesquite (Prosopis species; Fabaceae). Adult males sex-specifically produced a blend of eight common natural products, including the monoterpene alcohol (S)-α-terpineol; the monoterpenes (S)-limonene and terpinolene; the aromatic alcohols (R)-1-phenylethanol and 2-phenylethanol; and (E)-2-hexenol, (E)-2-hexenal, and 1-hexanol. Individual males produced the components in varying amounts, but (S)-α-terpineol and (E)-2-hexenal were always present and together constituted the majority of the blend. A synthetic reconstruction of the complete blend attracted both males and females of M. antennata during field bioassays, as did all subsets of the blend that included (S)-α-terpineol and (E)-2-hexenol. Adults were most strongly attracted to blends of the latter two compounds when in ratios approaching parity. Neither of the compounds were present in the bouquet of volatiles emitted by host plants of the larvae.


1988 ◽  
Vol 19 (3) ◽  
pp. 251-258 ◽  
Author(s):  
Virginia I. Wolfe ◽  
Suzanne D. Blocker ◽  
Norma J. Prater

Articulatory generalization of velar cognates /k/, /g/ in two phonologically disordered children was studied over time as a function of sequential word-morpheme position training. Although patterns of contextual acquisition differed, correct responses to the word-medial, inflected context (e.g., "picking," "hugging") occurred earlier and exceeded those to the word-medial, noninflected context (e.g., "bacon," "wagon"). This finding indicates that the common view of the word-medial position as a unitary concept is an oversimplification. Possible explanations for superior generalization to the word-medial, inflected position are discussed in terms of coarticulation, perceptual salience, and the representational integrity of the word.


2017 ◽  
Vol 68 (7) ◽  
pp. 1438-1441 ◽  
Author(s):  
Sorin Berbece ◽  
Dan Iliescu ◽  
Valeriu Ardeleanu ◽  
Alexandru Nicolau ◽  
Radu Cristian Jecan

Obesity represents a global health problem. According to the latest studies released by the World Health Organisation (WHO), 1.7 billion currently in excess of normal weight individuals, of which approx. 75% are overweight (body mass index - BMI 25 to 30). The common form of excess adipose tissue manifestation in overweight individuals is localized fat deposits with high (abdominal) or low (buttocks and thighs) disposition. Although the overweight can be corrected relatively easy by changing behavioral habits or food, a constant physical exercises program or following a diet food are not accessible to all through the efforts of will, financial and time involved. Several methods have been studied and tested over time to eliminate more or less invasive fat deposits with varying efficacy and adverse effects. Chemical lipolysis using phosphatidylcholine as the basic substance was initially used in hypercholesterolemia and its complications and was rapidly adopted in mesotherapy techniques for the treatment of fat deposits. This study reveals the results obtained using Dermastabilon on a sample of 16 patients, the time allocated to treatment and discomfort being minimal, and rapid and notable results. There were no side effects.


Author(s):  
Halil Kaya ◽  
Gaurango Banerjee

The paper examines the Sarbanes-Oxley (2002) Acts immediate impact on board composition and characteristics as well as possible reversals in its impact over time. Effects on directors age and tenure are analyzed over the 2001-06 sample period. Female participation in corporate boards is also studied in the pre-SOX and post-SOX periods. The dual roles of directors in being a member of the board as well as serving as either CEO, CFO, Chairman, Co-Chair, Founder, or Lead Director of their respective companies is also examined. We observe a short-term impact of SOX on board compositions due to changes seen in board characteristics between 2001 (pre-SOX), and 2003-05 short-term period (post-SOX). Also, we observe a reversal of board characteristics in 2006 to pre-SOX levels implying that the effects of SOX on board composition were short-lived, and needs to be monitored over time to ensure adherence to corporate accountability guidelines over the long-term.


2021 ◽  
pp. 089020702110173
Author(s):  
Nadin Beckmann ◽  
Damian P Birney ◽  
Amirali Minbashian ◽  
Jens F Beckmann

The study aimed to investigate the status of within-person state variability in neuroticism and conscientiousness as individual differences constructs by exploring their (a) temporal stability, (b) cross-context consistency, (c) empirical links to selected antecedents, and (d) empirical links to longer term trait variability. Employing a sample of professionals ( N = 346) from Australian organisations, personality state data together with situation appraisals were collected using experience sampling methodology in field and repeatedly in lab-like settings. Data on personality traits, cognitive ability, and motivational mindsets were collected at baseline and after two years. Contingent (situation contingencies) and non-contingent (relative SD) state variability indices were relatively stable over time and across contexts. Only a small number of predictive effects of state variability were observed, and these differed across contexts. Cognitive ability appeared to be associated with state variability under lab-like conditions. There was limited evidence of links between short-term state and long-term trait variability, except for a small effect for neuroticism. Some evidence of positive manifold was found for non-contingent variability. Systematic efforts are required to further elucidate the complex pattern of results regarding the antecedents, correlates and outcomes of individual differences in state variability.


Author(s):  
Erica Subrero ◽  
Irene Pellegrino ◽  
Marco Cucco

AbstractIn Odonates, female colour polymorphism is common and implies the presence of two or more female types with different colours and behaviours. To explain this phenomenon, several hypotheses have been proposed that consider morph frequency, population density, the presence of parasites, and mating behaviour. We studied the blue-tailed damselfly Ischnura elegans, a species with a blue androchrome morph and two gynochrome morphs (the common green infuscans, and the rare orange rufescens-obsoleta). The size of adult males and females, the presence of parasites, and pairing behaviour between males and the three female morphs was assessed in field conditions throughout the reproductive season in NW Italy. Moreover, growth and emergence success of larvae produced by the different morphs was analyzed in standardized conditions. In the field, males showed a preference for the gynochrome infuscans females, despite a similar frequency of androchrome females. In test conditions, male preference for the infuscans females was also observed. Paired males and paired androchrome females were larger than unpaired individuals, while there were no differences in size between paired and unpaired infuscans females. Males and androchrome females were more parasitized than infuscans females. The survival and emergence success of larvae produced by androchrome females was higher than those of offspring produced by the infuscans females. Our results suggest that a higher survival of progeny at the larval stage could counterbalance the higher parasitism and the lower pairing success of andromorph adult females and highlight the importance of considering the whole life-cycle in polymorphism studies.


Author(s):  
Allen D. Uhler ◽  
Jeffery H. Hardenstine ◽  
Deborah A. Edwards ◽  
Guilherme R. Lotufo

AbstractPolychlorinated biphenyls (PCBs) were added to certain marine vessel bottom paints as a plasticizer to improve the adhesion and durability of the paint. The most common PCB formulation used to amend such paints was Aroclor 1254. Fugitive Aroclor-containing paint chips generated from vessel maintenance and repair operations represent a potential source of PCB contamination to sediments. Limited published studies indicate that Aroclor-containing paint is largely inert and exhibits low PCB leaching into water; however, the rate and degree of leaching of PCBs from paint chips have not been directly studied. This laboratory-based study evaluated the rate and extent of leaching of PCBs from paint chips into freshwater. The results of this investigation demonstrate that the rate of PCB dissolution from paint chips decreased rapidly and exponentially over time. Based on this study, it is estimated that the rate of leaching of PCBs from paint chips would cease after approximately 3 years of exposure to water. When all leachable PCBs were exhausted, it is estimated that less than 1% of the mass of PCBs in the paint chips was amenable to dissolution. The results of this experiment suggest that Aroclor-containing paint chips found in sediments are likely short-term sources of dissolved-phase PCB to pore or surface waters and that the majority of the PCBs in paint chips remain in the paint matrix and unavailable for partitioning into water. Graphic Abstract


Author(s):  
Thomas L Rodebaugh ◽  
Madelyn R Frumkin ◽  
Angela M Reiersen ◽  
Eric J Lenze ◽  
Michael S Avidan ◽  
...  

Abstract Background The symptoms of COVID-19 appear to be heterogenous, and the typical course of these symptoms is unknown. Our objectives were to characterize the common trajectories of COVID-19 symptoms and assess how symptom course predicts other symptom changes as well as clinical deterioration. Methods 162 participants with acute COVID-19 responded to surveys up to 31 times for up to 17 days. Several statistical methods were used to characterize the temporal dynamics of these symptoms. Because nine participants showed clinical deterioration, we explored whether these participants showed any differences in symptom profiles. Results Trajectories varied greatly between individuals, with many having persistently severe symptoms or developing new symptoms several days after being diagnosed. A typical trajectory was for a symptom to improve at a decremental rate, with most symptoms still persisting to some degree at the end of the reporting period. The pattern of symptoms over time suggested a fluctuating course for many patients. Participants who showed clinical deterioration were more likely to present with higher reports of severity of cough and diarrhea. Conclusion The course of symptoms during the initial weeks of COVID-19 is highly heterogeneous and is neither predictable nor easily characterized using typical survey methods. This has implications for clinical care and early-treatment clinical trials. Additional research is needed to determine whether the decelerating improvement pattern seen in our data is related to the phenomenon of patients reporting long-term symptoms, and whether higher symptoms of diarrhea in early illness presages deterioration.


2021 ◽  
pp. 1-25
Author(s):  
Greg Patmore ◽  
Nikola Balnave ◽  
Olivera Marjanovic

While co-operatives are traditionally associated with workers, consumers, and farmers, the business model, with its emphasis on democracy and community, has also been adopted by small business owners, the self-employed, and professionals. These business co-operatives are distinct phenomenon, because they primarily consist of independent organizational entities that are not co-operatives and are generally in direct competition with one another. They are unique in that they bring together separate organizations that seek to combat market threats while adopting a philosophy based on co-operative principles. This article begins with an overview of the Australian co-operative landscape. It then defines the concept of business co-operatives and then draws upon the Visual Atlas of Australian Co-operatives History Project, which has developed a large database of Australian co-operatives over time and space, to examine the development of business co-operatives in Australia. It looks at where business co-operatives formed in the economy, the motivation underlying their formation, their average life spans, and their relationships with the broader co-operative movement. The article highlights the value of business co-operatives in introducing the values of participatory democracy and working for the common good into unanticipated markets and reinforcing the co-operative movement.


2019 ◽  
Vol 30 (2) ◽  
pp. 635-663
Author(s):  
Karin Mickelson

Abstract This contribution to the symposium on the economic exploitation of the commons focuses on the question of whether and to what extent the principle of the common heritage of mankind (CHM) imposes environmental limits on economic exploitation of the global commons. Focusing on the need to go beyond a unidimensional assessment of the principle, it considers how CHM was originally envisaged, the form it took in the deep seabed regime, in particular, how its role in that regime has developed over time and how it has been utilized as a basis for advocacy. It concludes with an assessment of CHM’s limitations and strategic advantages.


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