1. A spider mating plug functions to protect spermHe Jiang, Yongjia Zhan, Qingqing Wu, Huitao Zhang, Matjaž Kuntner, Lihong Tu, 2024, original scientific article Abstract: Mating plugs in animals are ubiquitous and are commonly interpreted to be products of mating strategies. In spiders, however, mating plugs may also take on functions beyond female remating prevention. Due to the vagaries of female genital (spermathecal) anatomy, most spiders face the problem of having to secure additional, non-anatomical, protection for transferred sperm. Here, we test the hypothesis that mating plugs, rather than (or in addition to) being adaptations for mating strategies, may serve as sperm protection mechanism. Based on a comparative study on 411 epigyna sampled from 36 families, 187 genera, 330 species of entelegyne spiders, our results confirm the necessity of a sperm protection mechanism. We divided the entelegyne spermathecae into four types: SEG, SED, SCG and SCD. We also studied detailed morphology of epigynal tracts in the spider Diphya wulingensis having the SEG type spermathecae, using 3D-reconstruction based on semi thin histological series section. In this species, we hypothesize that two distinct types of mating plug, the sperm plug and the secretion plug, serve different functions. Morphological details support this: sperm plugs are formed on a modified spermathecal wall by the spilled sperm, and function as a temporary protection mechanism to prevent sperm from leaking and desiccating, while secretion plugs function in postcopulation both as a permanent protection mechanism, and to prevent additional mating. Furthermore, with the modified spermathecal wall of S2 stalk, the problem of shunt of sperm input and output, and the possibility of female multiple mating have been resolved. Variation in spermathecal morphology also suggests that the problem of sperm protection might be resolved in different ways in spiders. Considering mating plugs of varying shapes and origins in the vast morphospace of spiders, we conclude that mating plugs might serve different purposes that relate both to mating strategies, as well as to sperm protection.
Keywords: spiders, mating strategies, mating plugs, sperm protection mechanism
Published in DiRROS: 19.06.2024; Views: 101; Downloads: 51
 Full text (6,93 MB)
This document has many files! More... |
2. Private forest owner willingness to mobilise wood from dense, small-diameter tree standsMatevž Triplat, Satu Helenius, Ruben Laina, Nike Krajnc, Thomas Kronholm, Zdenka Ženko, Teppo Hujala, 2023, original scientific article Abstract: Forests are a source of renewable biomass, and their utilisation will play a vital role in the transition towards a climate-neutral economy. Small-diameter tree management could contribute to this transition via providing renewable biomass for sustainable uses and fostering tree growth towards long-lifecycle bioproducts. The utilisation of small-diameter trees in the EU is still low since new technologies and work models are required to make the operations economically profitable, environmentally sound, and socially attractive. The supply of biomass from small-diameter tree stands is dependent on forest owners with diverse perceptions on their forests and diverse ownership objectives. However, there is scarce research on forest owner perceptions on small-diameter tree management, which encompasses home consumption, self-active work, and commercial forestry services. A survey in four EU countries was designed to identify the main factors affecting the motivation of forest owners to mobilise biomass from small-diameter stands. Factor and clustering analyses were used to identify four forest owner segments: weakly-engaged traders, well-being seekers, self-active profit-seekers, and well-informed service users. The willingness to utilise biomass from small-diameter tree stands and participate in the market was shaped by forest owner knowledge of forestry, economic and socio-cultural motivations, and sensitivity to service offerings. Forest owner preferences for market participation are heterogenous, and thus different policy implementation approaches are needed and proposed.
Keywords: customer profiles, factor analysis, forestry services, management objectives, biomass, communication strategies
Published in DiRROS: 05.01.2023; Views: 800; Downloads: 340
Full text (1,51 MB)
This document has many files! More... |
3. Additional exergames to regular tennis training improves cognitive-motor functions of children but may temporarily affect tennis technique : a single-blind randomized controlled trialLuka Šlosar, Eling D. de Bruin, Eduardo Bodnariuc Fontes, Matej Plevnik, Rado Pišot, Boštjan Šimunič, Uroš Marušič, 2021, original scientific article Abstract: This study evaluated the effects of an exergame program (TennisVirtua-4, Playstation Kinect) combined with traditional tennis training on autonomic regulation, tennis technique, gross motor skills, clinical reaction time, and cognitive inhibitory control in children. Sixty-three children were randomized into four groups (1st % two exergame and two regular trainings sessions/week, 2nd % one exergame and one regular training sessions/week, 3rd % two regular trainings sessions/week, and 4th % one regular training session/week) and compared at baseline, 6-month immediately post intervention and at 1-year follow-up post intervention. At 6-month post intervention the combined exergame and regular training sessions revealed: higher breathing frequency, heart rate (all ps % 0.001) and lower skin conductance levels (p = 0.001) during exergaming; additional benefits in the point of contact and kinetic chain elements of the tennis forehand and backhand technique (all ps % 0.001); negative impact on the shot preparation and the follow-through elements (all ps % 0.017); higher ball skills (as part of the gross motor skills) (p < 0.001); higher percentages of clinical reaction time improvement (1st %9.7% vs 3rd group %7.4% and 2nd %6.6% vs 4th group %4.4%, all ps % 0.003) and cognitive inhibitory control improvement in both congruent (1st %20.5% vs 3rd group %18.4% and 2nd %11.5% vs 4th group %9.6%, all ps % 0.05) and incongruent (1st group %19.1% vs 3rd group %12.5% and 2nd group %11.4% vs 4th group %6.5%, all ps % 0.001) trials. The 1-year follow-up test showed no differences in the tennis technique, clinical reaction time and cognitive inhibitory control improvement between groups with the same number of trainings per week. The findings support exergaming as an additional training tool, aimed to improve important cognitive-motor tennis skills by adding dynamics to the standardized training process. Caution should be placed to planning this training, e.g., in a mesocycle, since exergaming might decrease the improvement of specific tennis technique parts of the trainees. (ClinicalTrials.gov; ID: NCT03946436).
Keywords: tennis, training, performance, children, motor learning, cognitive learning, teaching, strategies
Published in DiRROS: 17.03.2021; Views: 1377; Downloads: 1105
Full text (1,81 MB)
This document has many files! More... |
4. Coping strategies of patients with advanced lung or colorectal cancer in six European countries : insights from the ACTION studyLea J. Jabbarian, Ida Joanna Korfage, Branka Červ, Johannes JM van Delden, Luc Deliens, Guido Miccinesi, Sheila Payne, Anna Thit Johnsen, Mariette Verkissen, Andrew Wilcock, Agnes van der Heide, Judith Anna Catharina Rietjens, 2020, review article Abstract: Objective: Even when medical treatments are limited, supporting patients' coping strategies could improve their quality of life. Greater understanding of patients' coping strategies, and influencing factors, can aid developing such support. We examined the prevalence of coping strategies and associated variables. Methods: We used sociodemographic and baseline data from the ACTION trial, including measures of Denial, Acceptance and Problem-focused coping (COPE; Brief COPE inventory), of patients with advanced cancer from six European countries. Clinicians provided clinical information. Linear mixed models with clustering at hospital level were used. Results: Data from 675 patients with stage III/ IV lung (342, 51%) or stage IV colorectal (333, 49%) cancer were used; mean age 66 (10 SD) years. Overall, patients scored low on Denial and high on Acceptance and Problem-focused coping. Older age was associated with higher scores on Denial than younger age ([beta] = 0.05; CI[0.023; 0.074]), and patients from Italy ([beta] = 1.57 CI[0.760; 2.388]) and Denmark ([beta] = 1.82 CI[0.881; 2.750]) scored higher on Denial than patients in other countries. Conclusions: Patients with advanced cancer predominantly used Acceptance and Problem-focused coping, and Denial to a lesser extent. Since the studied coping strategies of patients with advanced cancer vary between subpopulations, we recommend taking these factors into account when developing tailored interventions to support patients' coping strategies.
Keywords: ACTION study, lung cancer, colorectal cancer, coping strategies
Published in DiRROS: 29.07.2020; Views: 1788; Downloads: 1188
Full text (319,54 KB)
This document has many files! More... |
