Mucilage reduces leaf herbivory in Schreber’s watershield, Brasenia schreberi J.F. Gmel. (Cabombaceae)

Botany ◽  
2014 ◽  
Vol 92 (5) ◽  
pp. 412-416 ◽  
Author(s):  
K.A. Thompson ◽  
D.M. Sora ◽  
K.S. Cross ◽  
J.M. St. Germain ◽  
K. Cottenie

Insect herbivores negatively affect plants by consuming biomass that could otherwise be used for growth or reproduction. To reduce their impact, plants have evolved a wide range of antiherbivore defenses. Schreber’s watershield (Brasenia schreberi J.F. Gmel.; Cabombaceae) is a freshwater, aquatic plant that produces a thick mucilage on the underside of leaves and all underwater organs. The mucilage has been proposed as a mechanism of defense against herbivory, but this hypothesis is untested. We conducted a comparative study to determine whether the quantity of mucilage on the underside of leaves is associated with herbivore damage on the leaves. We found that leaves with the thickest mucilage layer were the least damaged. To determine whether mucilage is directly responsible for defense against herbivores, we conducted a manipulative study where we removed the mucilage from the abaxial surface of leaves. We found that demucilated leaves experienced higher amounts of herbivore damage than leaves with their mucilage left intact. We conclude that the mucilage produced by B. schreberi functions to reduce herbivory on leaves, although its association with underwater herbivores and its specific antiherbivore properties remain unknown.

Author(s):  
Pranav Madhav Kuber ◽  
Ehsan Rashedi

A new forklift backrest has been developed by incorporating adjustability concepts into the design to facilitate comfort to a wide range of users. We have conducted a comparative study between the new and original backrests to assess the effectiveness of design features. Using the phenomenon of restlessness, discomfort of the user was associated with the amount of body movement, where we have used a motion- capture system and a force platform to quantify the individuals’ movement for a wide range of body sizes. Meanwhile, subjective comfort and design feedback were collected using a questionnaire. Our results showed a reduction in the mean torso movement and the maximum center of pressure change of location by 300 and 6 mm, respectively, for the new design. Taking advantage of adjustability feature, the new backrest design exhibited enhanced comfort for longer durations and reduced magnitude of discomfort for a wide range of participants’ body sizes.


2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Lisa Parola

This essay derives from the primary need to make order between direct and indirect sources available for the reconstruction of the history of video art in Italy in the seventies. In fact, during the researches for the Ph.D. thesis it became clear that in most cases it is difficult to define, in terms of facts, which of the different historiographies should be taken into consideration to deepen the study of video art in Italy. Beyond legitimate differences of perspectives and methods, historiographical narratives all share similar issues and narrative structure. The first intention of the essay is, therefore, to compare the different historiographic narratives on Italian video art of the seventies, verifying their genealogy, the sources used and the accuracy of the narrated facts. For the selection of the corpus, it was decided to analyze in particular monographic volumes dealing with the history of the origins of video art in Italy. The aim was, in fact, to get a wide range of types of "narrations", as in the case of contemporary art and architecture magazines, which are examined in the second part of the essay. After the selection, for an analytical and comparative study of the various historiography, the essay focuses only on the Terza Biennale Internazionale della Giovane Pittura. Gennaio ’70. Comportamenti, oggetti e mediazioni (Third International Biennial of Young Painting. January '70. Behaviors, Objects and Mediations, 1970, Bologna), the exhibition which - after Lucio Fontana's pioneering experiments - is said to be the first sign of the arrival of videotape in Italy (called at the time videorecording), curated by Renato Barilli, Tommaso Trini, Andrea Emiliani and Maurizio Calvesi. The narration given so far of this exhibition appeared more mythological than historical and could be compared structurally to that of the many numerous beginnings that historiographyies on international video art identify as ‘first’ and ‘generative’. In the first part of the essay the 'facts' related to Gennaio ’70, as narrated by historiography on video art, are compared. In the second part the survey is carried out through some of the direct sources identified during the research, with the aim of answering to questions raised by the comparison between historiographies. Concluding, it is important to underline that the tapes containing the videos transmitted have not been found and seem to have disappeared since the ending of the exhibition. Nevertheless, the deepening of the works and documentation transmitted during the exhibition is possible thanks to other types of sources which give us many valuable information regarding video techniques and practices at the beginning of 1970 in Italy.


Author(s):  
Neha Yedala ◽  
Niket S. Kaisare

Heat recirculating microreactors are being investigated for coupling with thermoelectric generator (TEG) for power generation since they facilitate sustained combustion over a wide range of operating conditions. A major challenge...


Author(s):  
Imam Muzakky ◽  
Dwi Umi Novitasari ◽  
Siti Hamidah

Indonesia as a country that offers a wide range of diversity offers its own uniqueness. But unfortunately the diversity it also has the potential for conflict ( Rahardjo , 2010) . Not only the conflict between cultures and groups, as happened in intercollegiate martial arts such as pagarnusa, PSHT and Kerasakti. Objective The purpose of this study to determine the level of aggressiveness, collective pride and tolerance in three martial arts college , this is one of the factors of conflict is high aggressiveness, collective pride and a low level of tolerance. Methodology/Technique The study involved 30 members pagarnusa , 30 members and 30 members kerasakti PSHT . Research methods with quantitative approach. Findings – The findings of this study are a group of college kerasakti have the highest tolerance, low aggression and collective pride being. PSHT has a high level of aggressiveness being and collective tolerance pride being, while the pagarnusa Group aggressiveness levels that are low tolerance level and collective pride high. Findings The findings of this study are a group of college kerasakti have the highest tolerance, low aggression and collective pride being. PSHT has a high level of aggressiveness being and collective tolerance pride being, while the pagarnusa Group aggressiveness levels that are low tolerance level and collective pride high. Type of Paper Empirical paper Keywords: Martial Arts, Aggressiveness, Tolerance , Collective Pride


Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 865
Author(s):  
Zuzana Münzbergová ◽  
Jiří Skuhrovec

Data on plant herbivore damage as well as on herbivore performance have been previously used to identify key plant traits driving plant–herbivore interactions. The extent to which the two approaches lead to similar conclusions remains to be explored. We determined the effect of a free-living leaf-chewing generalist caterpillar, Spodoptera littoralis (Lepidoptera: Noctuidae), on leaf damage of 24 closely related plant species from the Carduoideae subfamily and the effect of these plant species on caterpillar growth. We used a wide range of physical defense leaf traits and leaf nutrient contents as the plant traits. Herbivore performance and leaf damage were affected by similar plant traits. Traits related to higher caterpillar mortality (higher leaf dissection, number, length and toughness of spines and lower trichome density) also led to higher leaf damage. This fits with the fact that each caterpillar was feeding on a single plant and, thus, had to consume more biomass of the less suitable plants to obtain the same amount of nutrients. The key plant traits driving plant–herbivore interactions identified based on data on herbivore performance largely corresponded to the traits identified as important based on data on leaf damage. This suggests that both types of data may be used to identify the key plant traits determining plant–herbivore interactions. It is, however, important to carefully distinguish whether the data on leaf damage were obtained in the field or in a controlled feeding experiment, as the patterns expected in the two environments may go in opposite directions.


Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3531 ◽  
Author(s):  
Lorenzo Manoni ◽  
Claudio Turchetti ◽  
Laura Falaschetti ◽  
Paolo Crippa

Wearable devices offer a convenient means to monitor biosignals in real time at relatively low cost, and provide continuous monitoring without causing any discomfort. Among signals that contain critical information about human body status, electromyography (EMG) signal is particular useful in monitoring muscle functionality and activity during sport, fitness, or daily life. In particular surface electromyography (sEMG) has proven to be a suitable technique in several health monitoring applications, thanks to its non-invasiveness and ease to use. However, recording EMG signals from multiple channels yields a large amount of data that increases the power consumption of wireless transmission thus reducing the sensor lifetime. Compressed sensing (CS) is a promising data acquisition solution that takes advantage of the signal sparseness in a particular basis to significantly reduce the number of samples needed to reconstruct the signal. As a large variety of algorithms have been developed in recent years with this technique, it is of paramount importance to assess their performance in order to meet the stringent energy constraints imposed in the design of low-power wireless body area networks (WBANs) for sEMG monitoring. The aim of this paper is to present a comprehensive comparative study of computational methods for CS reconstruction of EMG signals, giving some useful guidelines in the design of efficient low-power WBANs. For this purpose, four of the most common reconstruction algorithms used in practical applications have been deeply analyzed and compared both in terms of accuracy and speed, and the sparseness of the signal has been estimated in three different bases. A wide range of experiments are performed on real-world EMG biosignals coming from two different datasets, giving rise to two different independent case studies.


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3253
Author(s):  
Silvia Terrile ◽  
Miguel Argüelles ◽  
Antonio Barrientos

Soft grippers have experienced a growing interest due to their considerable flexibility that allows them to grasp a variety of objects, in contrast to hard grippers, which are designed for a specific item. One of their most remarkable characteristics is the ability to manipulate soft objects without damaging them. This, together with their wide range of applications and the use of novels materials and technologies, renders them a very robust device. In this paper, we present a comparison of different technologies for soft robotics grippers. We fabricated and tested four grippers. Two use pneumatic actuation (the gripper with chambered fingers and the jamming gripper), while the other two employ electromechanical actuation (the tendon driver gripper and the gripper with passive structure). For the experiments, a group of twelve objects with different mechanical and geometrical properties have been selected. Furthermore, we analyzed the effect of the environmental conditions on the grippers, by testing each object in three different environments: normal, humid, and dusty. The aim of this comparative study is to show the different performances of different grippers tested under the same conditions. Our findings indicate that we can highlight that the mechanical gripper with a passive structure shows greater robustness.


2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Shiqi Hu ◽  
Gaojie Li ◽  
Jingjing Yang ◽  
Hongwei Hou

Genomics is a discipline in genetics that studies the genome composition of organisms and the precise structure of genes and their expression and regulation. Genomics research has resolved many problems where other biological methods have failed. Here, we summarize advances in aquatic plant genomics with a focus on molecular markers, the genes related to photosynthesis and stress tolerance, comparative study of genomes and genome/transcriptome sequencing technology.


1981 ◽  
Vol 38 (2) ◽  
pp. 125-135 ◽  
Author(s):  
Nikos Stamatis ◽  
George Yannopoulos ◽  
Michael Pelecanos

SUMMARYA comparative study of two male recombination factors (31. 1 MRF and 23. 5 MRF) isolated from the same Southern Greek natural population, revealed specific differences in their activities. 23. 5 MRF induces female sterility due to atrophie ovaries at a wide range of temperatures while 31. 1 MRF does so only at high temperatures. The gross morphology of the atrophie ovaries was the same and unilaterally affected pairs were found in the F1of crosses with both 23. 5 and 31. 1 MRF. Furthermore, 23. 5 MRF induces: (a) lower frequencies of abnormal anaphases I and II than 31. 1 MRF, (b) higher frequencies of ‘double crossovers’ resulting from deficiences or duplications, (c) large clusters of recombinants, suggesting premeiotic origin and (d) cases where one of the non-recombinant phenotypes was not produced. Such cases have never been observed with 31. 1 MRF. Moreover, the cytoplasm of theCy L4/Pmstrain that suppresses 31. 1 MRF does not affect the activities of 23. 5 MRF. Hypotheses to explain the different behaviour of the two factors are presented and discussed.


2012 ◽  
Vol 3 (3) ◽  
pp. 78-82 ◽  
Author(s):  
MS Srinivas ◽  
Vickram Sundaram ◽  
M Ramesh Pathy ◽  
TB Sridharan

ABSTRACT Aim To elucidate the concentration of the protein and cholesterol in different fractions of human semen from different infertile categories and comparing them with the fertile group. Materials and methods The human semen was collected from different infertile categories including oligoasthenospermia, asthenospermia, azoospermia, normospermia, oligospermia and fertile group. Immediately after collection, the semen analysis was done as per WHO standard protocols. After that, the semen was centrifuged to get the different fractions. Four main fractions were obtained, (1) spermatozoa, (2) debris or material that precipitates at 12 K rpm for 10 minutes, (3) prostasomes which was precipitated at 20K rpm for 120 minutes, (4) seminal plasma. The protein concentration was done by Lowry's method and cholesterol was estimated by diagnostic kit. Results Sodium dodecyl sulfate—polyacrylamide gel electrophoresis (SDS PAGE) was run for all the categories of semen samples for their seminal plasma and the fertility associated protein was identified. A significant difference was found in the concentration of proteins in all subfractions when compared between control and infertile categories. Almost 86% of the protein was recovered from soluble fraction. In case of azoospermia, the protein content was very low when compared with fertile group. Seminal plasma proteins were visualized by silver staining. The molecular weight of the protein bands were ranging from 6.5 to 205 kDa. The band with molecular weight around 55 kDa was found to be missing in case of oligoasthenospermia. This particular protein is said to be fertility associated protein. The content of cholesterol for different subfraction of the human semen samples from infertile and fertile samples was compared. A wide range of cholesterol was recovered from prostasomes, that too purified. Conclusion A thrive study have to be done in all the subfractions of the semen irrespective of the category of samples to know the exact function of the each subfractions in terms of protein and cholesterol distribution. How to cite this article Sundaram V, Srinivas MS, Rao KA, Pathy MR, Sridharan TB. A Comparative Study of Distribution of Protein and Cholesterol in Various Fractions of Human Semen from Infertile and Fertile Subjects. Int J Infertility Fetal Med 2012;3(3):78-82.


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