scholarly journals Almost all known sauropod necks are incomplete and distorted

Author(s):  
Michael P Taylor

Sauropods are familiar dinosaurs, immediately recognisable by their great size and long necks. However, their necks are much less well known than is usually assumed. Very few complete necks have been described in the literature, and even important specimens such as the Carnegie Diplodocus and Apatosaurus, and the giant Berlin brachiosaur, in fact have imperfectly known necks. In older specimens, missing bone is often difficult to spot due to over-enthusiastic restoration. Worse still, even those vertebrae that are complete are often badly distorted – for example, in consecutive cervicals of the Carnegie Diplodocus CM 84, the aspect ratio of the posterior articular facet of the centrum varies so dramatically that C14 appears 35% broader proportionally than C13. Widespread incompleteness and distortion are both inevitable due to sauropod anatomy: large size made it almost impossible for whole individuals to be preserved because sediment cannot be deposited quickly enough to cover a giant carcass; and distortion of presacral vertebrae is common due their lightweight pneumatic construction. This ubiquitous incompleteness and unpredictable distortion compromise attempts to determine habitual neck posture and range of motion by modelling articulations between vertebrae.

2015 ◽  
Author(s):  
Michael P Taylor

Sauropods are familiar dinosaurs, immediately recognisable by their great size and long necks. However, their necks are much less well known than is usually assumed. Very few complete necks have been described in the literature, and even important specimens such as the Carnegie Diplodocus and Apatosaurus, and the giant Berlin brachiosaur, in fact have imperfectly known necks. In older specimens, missing bone is often difficult to spot due to over-enthusiastic restoration. Worse still, even those vertebrae that are complete are often badly distorted – for example, in consecutive cervicals of the Carnegie Diplodocus CM 84, the aspect ratio of the posterior articular facet of the centrum varies so dramatically that C14 appears 35% broader proportionally than C13. Widespread incompleteness and distortion are both inevitable due to sauropod anatomy: large size made it almost impossible for whole individuals to be preserved because sediment cannot be deposited quickly enough to cover a giant carcass; and distortion of presacral vertebrae is common due their lightweight pneumatic construction. This ubiquitous incompleteness and unpredictable distortion compromise attempts to determine habitual neck posture and range of motion by modelling articulations between vertebrae.


1978 ◽  
Vol 56 (9) ◽  
pp. 2055-2057 ◽  
Author(s):  
J. W. Moore ◽  
I. A. Moore

Descriptions of larvae of Procladius denticulatus, Procladius culiciformis, Procladius freemani, and Procladius bellus collected from Yellowknife Bay (lat., 62°25′; long., 114°20′) are given. Procladius denticulatus was separated from the other species by its large size, a character which always proved distinctive. Procladius culiciformis and P. freemani were separated from one another through several measurements including those of the basal antennal segment and the basal palpal segment. Almost all characters of the head were useful in distinguishing the much smaller P. bellus from the other species.


Applied laser ◽  
2010 ◽  
Vol 30 (3) ◽  
pp. 219-222
Author(s):  
肖利刚 Xiao Ligang ◽  
李强 Li Qiang ◽  
郭渭荣 Guo Weirong ◽  
姜梦华 Jiang Menghua

2021 ◽  
pp. 118-125
Author(s):  
Farooq Al-Janabi ◽  
◽  
Mandeep Jit Singh ◽  
Amar Partap Singh Pharwaha

Antennas are the most important unit in almost all wireless communications, which played the key of transmitting the radiating electromagnetic waves after converting it from electrical signal. In this paper, designed an antenna that is capable to operate at frequencies between 12 GHz – 18 GHz for Ku band, and 26.5 GHz – 40 GHz for Ka band. This antenna was designed to overcome the narrow bandwidth, low gain, and large size of most satellite application antennas. By using a square shaped patch on a 4.3 dielectric constant substrate, modified and optimized the dimensions of the patch element, this antenna operated on dual-band frequencies between 12 GHz – 18 GHz and 26.5 GHz – 40 GHz, which satisfies the required bandwidth for satellite application. The antenna design was simulated using CST Microwave Studio software to analyze and evaluate the performance of the antenna design visibility.


2018 ◽  
Author(s):  
Stephen Foley ◽  
Tim Lueddecke ◽  
Dong-Qiang Chen ◽  
Henrik Krehenwinkel ◽  
Sven Kuenzel ◽  
...  

Mygalomorph spiders of the family Theraphosidae, known to the broader public as tarantulas, are among the most recognizable arachnids on earth due to their large size and widespread distribution. Their use of urticating setae is a notable adaptation that has evolved exclusively in certain New World theraphosids. Thus far, the evolutionary history of Theraphosidae remains poorly understood; theraphosid systematics still largely relies on morphological datasets, which suffer from high degrees of homoplasy, and traditional targeted sequencing of preselected genes failed to provide strong support for supra-generic clades (i.e. particularly those broader than subfamilies). In this study, we provide the first robust phylogenetic hypothesis of theraphosid evolution inferred from transcriptome data. A core ortholog approach was used to generate a phylogeny from 2460 orthologous genes across 25 theraphosid genera, representing all of the major theraphosid subfamilies, except Selenogyrinae. For the first time our phylogeny recovers a monophyletic group that comprises the vast majority of New World theraphosid subfamilies including Aviculariinae and Theraphosinae. Concurrently, we provide additional evidence for the integrity of questionable subfamilies, such as Poecilotheriinae and Psalmopoeinae, and support the non-monophyly of Ischnocolinae. The deeper relationships between almost all subfamilies are confidently inferred for the first time. We also used our phylogeny in tandem with published morphological data to perform ancestral state analyses on urticating setae. This revealed that the evolution of this important defensive trait might be explained by three equally parsimonious scenarios.


Author(s):  
Rika Sato ◽  
Norihiko Saga ◽  
Naoki Saito ◽  
Seiji Chonan

It is called contracture that a joint’s range of motion is restricted. Range of motion exercise is effective to prevent contracture. However, if range of motion exercise by the physiotherapist is performed, a range of motion will improve, but if time not to exercise is long, contracture will decrease again. Then, a rehabilitation instrument for passive range-of-motion exercise which can use after exercise by the physiotherapist is required. A CPM for a knee is developed as such an instrument, and it is also used for an ankle. But, most of instrument used motors to get a high power. So, those are heavy and large size. Installation and movement of instruments at facilities are difficult, and it is also difficult to use freely at home.


2020 ◽  
Author(s):  
Yuping Chen ◽  
Bruce Futcher

Abstract Cells divide with appropriate frequency by coupling division to growth—that is, cells divide only when they have grown sufficiently large. This process is poorly understood, but has been studied using cell size mutants. In principle, mutations affecting cell size could affect the mean size (“set-point” mutants), or they could affect the variability of sizes (“homeostasis” mutants). In practice, almost all known size mutants affect set-point, with little effect on size homeostasis. One model for size-dependent division depends on a size-dependent gene expression program: Activators of cell division are over-expressed at larger and larger sizes, while inhibitors are under-expressed. At sufficiently large size, activators overcome inhibitors, and the cell divides. Amounts of activators and inhibitors determine the set-point, but the gene expression program (the rate at which expression changes with cell size) determines the breadth of the size distribution (homeostasis). In this model, set-point mutants identify cell cycle activators and inhibitors, while homeostasis mutants identify regulators that couple expression of activators and inhibitors to size. We consider recent results suggesting that increased cell size causes senescence, and suggest that at very large sizes, an excess of DNA binding proteins leads to size induced senescence.


1973 ◽  
Vol 30 (12) ◽  
pp. 2085-2095 ◽  
Author(s):  
Y. Asada

Fishery regulations in Japan derive from the "Old Fisheries Law" of 1901. This law recognized and legalized traditional institutions and practices. In 1949 a new law replaced the "Old Fisheries Law" and this in turn was amended substantially in 1962.From the legal viewpoint fisheries are divided into three categories, "Fishing Rights Fisheries," "License Fisheries," and "Other Fisheries." License Fisheries produce 60% of catches and this proportion has gradually increased over many years. Coastal Fisheries are controlled by the Fishing Rights system. "Common Fishing Rights" are those that enable fishermen to exploit a certain area of water in order to harvest shellfish and seaweeds and to operate small types of fixed gear and small mobile gears such as beach seines set from nonmotorized craft. "Set Net Fishing Rights" are granted for gears fixed in water shallower than 27 m. "Demarcated Fishing Rights" enable holders to engage in fish culture within a given coastal area. Fishing Rights are monopolistic rights to engage in certain fisheries in certain areas of public waters. They are thus property rights, and in legal transactions most of the same provisions concerning land apply to them.The major fisheries are controlled by licenses. A fishing license legally exempts an individual from general prohibitions declared for the purpose of conservation or the maintenance of order in the exploitation of fishing grounds. There are two categories, licenses granted by the Minister of Agriculture and Forestry, and licenses granted by Prefectural Governors. The former licenses are required to engage in fisheries for which national control is considered necessary because of the large size of the vessels engaged, the wide area of fishing operation, the existence of international fishery agreements, and the nature of the fishing grounds, etc. Seventeen fisheries come under these licenses. Prefectural Governors issue licenses to vessels engaged in fisheries next in importance to the above group. The number of vessels to be licensed in each fishery is determined in consultation with Fisheries Coordination Committees by size-class of vessels, fishing area, and periods of operation. Licenses are subject to restrictions in respect to areas fished, closed seasons, vessel tonnage, equipment and power, minimum size of fish caught, and other things.All Japanese fisheries are controlled as a unit. Almost all are limited in the number of vessels that may take part. In recent years there have been few fisheries where the number of licenses issued has increased, but there has been a rise in the size of vessels and the quality of their equipment. Since fishing effort is controlled by the limitation on the number of licenses, in several instances their number has been reduced when exploitation seemed too high. In some cases vessels have been transferred to other fisheries; in others those forced out have been compensated by those remaining. But since renewal is nearly assured the license acquires value, and investments and loans are made taking the license as security. There is no fee charged for the licenses. It would have been better if one were, and the income used to compensate those who are forced out.A "tonnage supplement system" is used to reduce the effects of increase in fishing power resulting from the use of larger and more efficient vessels within the licensing system. To replace a vessel with another of larger size, the equivalent extra tonnage must be retired by purchase of a license or some other means.The system used in Japan arose in response to conditions in that country, and is regarded as successful. Other countries considering license limitations should consider their special problems to judge whether such a system is appropriate.


2005 ◽  
Vol 52 (2) ◽  
pp. 55-59 ◽  
Author(s):  
Zoran Vukasinovic ◽  
Dj. Spasovski ◽  
Goran Cobeljic

Authors have reviewed their eight years long experience with triple pelvic osteotomy. They are explaining the way of introduction of this procedure in everyday clinical practice. Sixty six hips were operated using Tonnis-Vladimirov method in fifty five patients of the average age of 15 years and four months. Treatment results were evaluated, both anatomically and functionally. Anatomic improvement was detected by measuring CE angle of Wiberg. Preoperatively it ranged from -6 to 33 degrees (16,4+10,8 degrees), at the end of treatment it ranged from 15 to 68 degrees (43,6+11,8 degrees) - the difference has proven to be statistically highly significant (Student test t=-14,36, p<0,01). Functional improvement (absence of waddling gait or limp, as well as better range of motion) was detected in almost all the cases, although the difference wasn't statistically significant. Also, they are presenting some, very rare, complications - asymptomatic pubic and/or ischial nonunion in seven patients.


2006 ◽  
Vol 134 (1-2) ◽  
pp. 49-53 ◽  
Author(s):  
Zoran Vukasinovic ◽  
Dusko Spasovski

Authors reviewed their eight-year long experience with triple pelvic osteotomy. They explained the way of introduction of this procedure into everyday clinical practice. Seventy hips were operated using Tonnis-Vladimirov method in fifty nine patients of an average age of 15 years and one month. Treatment results were evaluated, both anatomically and functionally. Anatomic improvement was recorded by measuring the CE angle of Wiberg. Preoperatively, it ranged from -6 to 33 degrees (16.1?10.2 degrees), and at the end of treatment, it ranged from 15 to 68 degrees (43.1?11.1 degrees) - the difference proved to be highly significant (Student test t=-14.27, p<0.01). Functional improvement (absence of waddling gait or limp as well as better range of motion) was noted in almost all cases, although the difference was not statistically significant. In addition, the authors presented some very rare complications - asymptomatic pubic and/or ischial nonunion in seven patients.


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