Nanomechanical sensors for direct and rapid characterization of sperm motility based on nanoscale vibrations

Nanoscale ◽  
2017 ◽  
Vol 9 (46) ◽  
pp. 18258-18267 ◽  
Author(s):  
Shangquan Wu ◽  
Zhiguo Zhang ◽  
Xiarong Zhou ◽  
Hong Liu ◽  
Changguo Xue ◽  
...  

A nanomechanical biosensor was developed for gaining insight into the relationship between the sperm viability and nanomechanical fluctuation.

Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


2021 ◽  
Author(s):  
◽  
David Laidler

<p>The relationship between notions of ‘history’ and ‘myth’ is a familiar dilemma within the field of historiography. As this thesis will seek to demonstrate, myth – defined here as evaluative representations of the past to suit demands of the present – is virtually indistinguishable from history, insofar as both are constructed from the same raw materials: subjective remembrances. Through an examination of mythical representations of physical places, this thesis will present a model to explain how myth is constructed, thereby emphasising the intimate and problematic relationship between the aforementioned categories.    In short, myth making occurs when memories travel through liminal space from one individual to the next, with said liminal points allowing for degradation and transmutation. The further along one is in the chain, the more one is dependent on myth. Through electing to focus on two such locales that have been of particular interest to me – Harlem during the jazz age and The Bronx during the origins of hip hop – I was able to adopt an auto-ethnographic perspective, gaining insight into the extent to which my understanding was dependent on a series of compounding representations. Further, these areas also draw attention to how such representation can broaden or localise, depending on the myth and the purpose of its invocation. In different contexts and different historical narratives, different areas within New York City have been subjected to the same process, which can account for the pervasive idea of ‘New York’ that continues to circulate.</p>


1988 ◽  
Vol 90 (2) ◽  
pp. 237-245
Author(s):  
J.M. Lord ◽  
J.A. Thick ◽  
C.M. Bunce ◽  
A.M. Taylor ◽  
P.H. Gallimore ◽  
...  

The monoclonal antibody AGF2.3 identifies a nuclear envelope protein that is restricted to certain cell types. In particular, this antigen shows a reduced level of expression during haemopoietic cell maturation. In this study, we have examined the relationship of this protein to known nuclear envelope proteins that have a similar molecular mass. Antigen extraction and immunoelectron microscope studies revealed that the AGF2.3 protein is an integral membrane protein present at both the inner and outer aspects of the nuclear envelope. The protein is not associated with nuclear pores and therefore is distinct from pore complex proteins. The AGF2.3 protein does not have ATPase activity. Therefore, this protein is also distinct from a myosin heavy chain-like ATPase that is associated with the nuclear envelope. The AGF2.3 antibody identifies a novel nuclear envelope protein. Further studies of the biochemical nature of the AGF2.3 protein should provide insight into novel cellular processes at the nuclear envelope relating to the lineage or maturation status of cells.


2013 ◽  
Vol 93 (2) ◽  
pp. 185-192 ◽  
Author(s):  
B. J. Awda ◽  
S. P. Miller ◽  
Y. R. Montanholi ◽  
G. Vander Voort ◽  
T. Caldwell ◽  
...  

Awda, B. J., Miller, S. P., Montanholi, Y. R., Vander Voort, G., Caldwell, T., Buhr, M. M. and Swanson, K. C. 2013. The relationship between feed efficiency traits and fertility in young beef bulls. Can. J. Anim. Sci. 93: 185–192. Great efforts have been taken in recent years for improving feed efficiency in beef cattle. Despite there being several studies on biological factors associated with this trait, little is known about the potential relationships between fertility and feed efficiency in beef cattle. The objective of this study was to examine the relationship between feed efficiency traits and bull fertility traits [sperm motility, viability and scrotal circumference (SC)]. From a total of 328 crossbred beef bulls that were subjected to a performance test (112 d in each of 6 yr), SC was measured and semen collected from 110 bulls using the electroejaculation method (average age±SE=417±2.5 d). Sperm were extended, cooled, and frozen in liquid nitrogen. Two residual feed intake (RFI) measures were considered with different prediction models for dry matter intake (DMI), RFIKoch included size and growth rate and RFIbkft included the additional adjustment for backfat thickness (BKFT). Sperm viability, motility and progressive motility of the 10 bulls with the greatest RFIKoch (Hi-RFIKoch) were greater than those of the 10 bulls with the lowest RFIKoch (Lo-RFIKoch; P<0.05, 0.01, and 0.05, respectively). Sperm motility (P<0.01), progressive motility and SC (P<0.05) of the 10 bulls with the greatest RFIbkft (Hi-RFIbkft) were greater than those of the 10 bulls with the lowest RFIbkft (Lo-RFIbkft). In summary, these data indicate that young beef bulls with greater feed efficiency have decreased sperm motility, sperm viability and SC, which is an undesirable effect of selection for improved feed efficiency that needs to be addressed through multiple trait selection.


Lubricants ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 70 ◽  
Author(s):  
Michael Schertzer ◽  
Patricia Iglesias

This work presents a meta-analysis that compares the suitability of various parameters used to characterize wettability in tribological systems. It also examines the relationship between wettability and the friction factor for multiple lubricant-surface pairings. The characterization of wetting behavior was similar when using the contact angle between a lubricant and surface and various dimensional and dimensionless formulations of a spreading parameter. It was possible to identify hydrodynamic, boundary, and mixed lubrication regimes by combining a dimensionless wettability parameter with the specific film thickness for a variety of neat ionic liquids and magnetorheological fluids in contact with metallic, thermoplastic, and elastic surfaces. This characterization was possible using multiple dimensionless wettability parameters, but those that can be fully determined using only the contact angle may be preferred by experimentalists. The use of dimensional and dimensionless wettability parameters that included polar and disperse components of surface tension and surface energy did not appear to provide additional insight into the wettability or frictional performance for the tribological system examined here.


mSystems ◽  
2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Sam Benkwitz-Bedford ◽  
Martin Palm ◽  
Talip Yasir Demirtas ◽  
Ville Mustonen ◽  
Anne Farewell ◽  
...  

Predicting bacterial growth from genome sequences is important for a rapid characterization of strains in clinical diagnostics and to disclose candidate novel targets for anti-infective drugs. Previous studies have dissected the relationship between bacterial growth and genotype in mutant libraries for laboratory strains, yet no study so far has examined the predictive power of genome sequence in natural strains.


10.28945/3418 ◽  
2016 ◽  
Vol 15 ◽  
pp. 089-108 ◽  
Author(s):  
Jamie Costley ◽  
Christopher Lange

Understanding the relationship between social presence and critical thinking is useful for gaining insight into the interaction and discourse of learners online. Further study of how these two presences interact is important because research has shown a wide variety of relationships, both positive and negative, between social presence and critical thinking. The aim of this study is to investigate social presence and critical thinking using discourse analysis in the hope that it will deepen and broaden our understanding of the relationship between these important facets of learner discourse. Using quantitative analysis, an online forum used by students at a national university in Korea (n=219) was analyzed by taking 900 forum posts to determine the levels of social presence and critical thinking in each post. The relationships between social presence and critical thinking were analyzed and the results show that social presence and critical thinking have a negative correlation. This highlights the need for awareness of learner discourse, as an increase in social presence may lead to a decrease in critical thinking and vice versa. The likely cause of this is that learners tend not to change the discourse once the discourse within a particular context has been set.


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