Breaking-points, 1958-59

2021 ◽  
pp. 268-285
Author(s):  
John Haffenden
Keyword(s):  
Author(s):  
David J Marlin ◽  
Kirstie Pickles ◽  
Roberta Ferro de Godoy ◽  
Jane M Williams

A recent survey by the authors of the present study indicated that headcollar (halter, USA) related incidents resulting in horse injuries may be common. From the survey, 134 incidents involving horse fractures and 167 fatalities were reported. Headcollar design and materials vary markedly from traditional leather to “safety” headcollars and safety devices. Despite their almost universal use, there has been minimal study as to how these items function or specifications for performance. The aim of the present study was to select a range of commercially available standard headcollars and a number of safety devices, to test the force required to break or release them. Safety devices selected included baler twine, which is widely used by equestrians to attach a horse by a headcollar to a lead rope and in turn to a fixture. This system practice is perceived to increase safety. Devices were subjected to increasing load in the poll to lead-rope attachment axis (i.e. to simulate a horse pulling backward) using a custom-made steel rig incorporating an electric 1000 kg winch. The force was increased incrementally until either the headcollar or device opened or failed. The lowest mean opening force of 357 ± 50 N was for a safety headcollar, which is equivalent to a load of approximately 36 kg. The highest breaking force was 5798 ± 265 N for one of the eight different webbing headcollars tested. Breaking for safety devices ranged from 354 ± 121 N for “fine” baler twine to 1348 ± 307 N for a “heavy duty” baler twine. Variability in opening force was lowest in two of the webbing headcollars (CV < 5%) despite these having very high breaking points (>3500 N). The greatest variability was found for fine baler twine (CV = 34%) and one of the commercial safety devices (CV = 38%). The range of opening forces and variability in opening forces for standard headcollars, safety headcollars and safety devices is a cause for concern and may give horse owners/handlers a false sense of security with regards to safety, and actually predispose horses and handlers to an increased risk of injury.


2021 ◽  
Vol 81 (6) ◽  
pp. 406-413
Author(s):  
Norbert Ricken

Abstract As familiar and self-evident as what is meant by ›helping‹ may seem at first, it is difficult to define ›helping‹ in a precise conceptual way. Against this backdrop, the question of what ›helping‹ is will be taken up and dealt with from a theoretical point of view. The path taken to work out and systematically define the form of helping leads to the discussion of some of the (predetermined) breaking points built into it and to the conclusion that ›helping‹ must be categorically defined differently. Recent anthropological research also suggests this by referring to the social-theoretical embedding of individuals and leaving behind individual-theoretical understandings of isolated individuals who would then enter into a relationship with each other.


PLoS ONE ◽  
2013 ◽  
Vol 8 (7) ◽  
pp. e69333 ◽  
Author(s):  
Adam P. Ross ◽  
M. Adela Mansilla ◽  
Youngshik Choe ◽  
Simon Helminski ◽  
Richard Sturm ◽  
...  

2015 ◽  
Author(s):  
Clemens L Weiß ◽  
Verena J Schuenemann ◽  
Jane Devos ◽  
Gautam Shirsekar ◽  
Ella Reiter ◽  
...  

Herbaria archive a record of changes of worldwide plant biodiversity harboring millions of specimens that contain DNA suitable for genome sequencing. To profit from this resource, it is fundamental to understand in detail the process of DNA degradation in herbarium specimens. We investigated patterns of DNA fragmentation -length and base composition at breaking points-, and nucleotide misincorporation by analyzing 86 herbarium samples spanning the last 300 years using Illumina shot-gun sequencing. We found an exponential decay relationship between DNA fragmentation and time, and estimated a per nucleotide fragmentation rate of 1.66 x 10-4 per year, which is ten times faster than the rate estimated for fossilized bones. Additionally, we found that strand breaks occur specially before purines, and that depurination-driven DNA breakage occurs constantly through time and can to a great extent explain decreasing fragment length over time. Similar of what has been found analyzing ancient DNA from bones, we found a strong correlation between the deamination-driven accumulation of cytosine (C) to thymine (T) substitutions and time, which reinforces the importance of substitution patterns to authenticate the ancient/historical nature of DNA fragments. Accurate estimations of DNA degradation through time will allow informed decisions about laboratory and computational procedures to take advantage of the vast collection of worldwide herbarium specimens.


1995 ◽  
pp. 7-18
Author(s):  
Claudine Raynaud ◽  
Peter Vernon
Keyword(s):  

1986 ◽  
Vol 143 (12) ◽  
pp. 1613-1613
Author(s):  
N. C. A.
Keyword(s):  

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