Hypertrophy and proliferation of skeletal muscle fibers from aged quail

1995 ◽  
Vol 78 (1) ◽  
pp. 293-299 ◽  
Author(s):  
J. A. Carson ◽  
M. Yamaguchi ◽  
S. E. Alway
Keyword(s):  
Muscle Mass ◽  
Fiber Type ◽  
Right Wing ◽  
Left Wing ◽  
Cross Sectional ◽  
Anterior Latissimus Dorsi ◽  
Fiber Number ◽  
Fiber Type Distribution ◽  
Distribution Shifts ◽  
The Right

The purpose of this study was to determined whether fibers in the anterior latissimus dorsi (ALD) muscle from aged Japanese quail have decreased hypertrophic or proliferative responses to 30 days of stretch overload compared with fibers from adult birds. Two groups of quail were studied, 12-wk-old quail (adult; n = 16) and 90-wk-old quail (aged; n = 16). The left wing of each bird was overloaded with a weight corresponding to 10% of the bird's body weight, and the right wing served as the intra-animal control. Quails were killed after 30 days of stretch overload. Total fiber number was quantified by counting all the fibers in a transverse section from the midbelly of the ALD muscle. ALD muscles in aged quails retained the capacity to increase their muscle mass (145%), total fiber number (49%), and fiber cross-sectional area (54%) in response to stretch overload. The ALD muscle in aged quail had a significantly lower increase in muscle mass (33%) and mass corrected for nonmuscle tissue (36%) compared with the ALD from young adult birds. Age had no effect on fiber type distribution shifts with stretch. These results suggest that although muscles in old birds have a substantial ability to adapt to enlarge, stretch-induced hypertrophy is attenuated in muscles from old quail.

Progressive stretch overload of skeletal muscle results in hypertrophy before hyperplasia

1993 ◽  
Vol 75 (3) ◽  
pp. 1263-1271 ◽  
Author(s):  
J. Antonio ◽  
W. J. Gonyea
Keyword(s):  
Latissimus Dorsi ◽  
Critical Size ◽  
Muscle Length ◽  
Progressive Increase ◽  
Right Wing ◽  
Left Wing ◽  
Anterior Latissimus Dorsi ◽  
Fiber Number ◽  
The Right ◽  
Large Muscle

Intermittent stretch of the anterior latissimus dorsi (ALD) muscle produces fiber hypertrophy without fiber hyperplasia (J. Appl. Physiol. 74: 1893–1898, 1993). This study was undertaken to determine if a progressive increase in load and duration of stretch would induce extremely large muscle fiber areas or if the fibers would reach a critical size before the onset of fiber hyperplasia. Weights ranging from 10 to 35% of the bird's mass were attached to the right wing of 26 adult quail while the left wing served as the intra-animal control. The stretch protocol was as follows: day 1 (10% wt), days 2 and 3 (rest), day 4 (15% wt), days 5–7 (rest), day 8 (20% wt), days 9 and 10 (rest), days 11–14 (25% wt), days 15 and 16 (rest), and days 17–38 (35% wt). Birds were killed after 12, 16, 20, 24, and 28 days of stretch not including rest days. Muscle mass increased 174% (12 days), 196% (16 days), 225% (20 days), 264% (24 days), and 318% (28 days). Muscle length increased 60% (12 days), 34% (16 days), 59% (20 days), 50% (24 days), and 51% (28 days). Mean fiber area increased 111% (12 days), 142% (16 days), 75% (20 days), 90% (24 days), and 39% (28 days). Fiber number, which was measured histologically, increased significantly by 82% only in the 28 days of stretch group. The percentage of slow tonic fibers did not change for any of the time points examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Perpetuation of muscle fibers after removal of stretch in the Japanese quail

1991 ◽  
Vol 260 (3) ◽  
pp. C400-C408 ◽  
Author(s):  
S. E. Alway
Keyword(s):  
Japanese Quail ◽  
Muscle Fibers ◽  
Control Area ◽  
Right Wing ◽  
Left Wing ◽  
Fiber Size ◽  
Anterior Latissimus Dorsi ◽  
Fiber Number ◽  
Nitric Acid Digestion ◽  
The Right

Stretch-overload has been shown to increase muscle mass in the anterior latissimus dorsi (ALD) of the adult quail by increasing both fiber size and number, but it is not known whether the new muscle fibers or fiber size is maintained after removal of the stretch stimulus. A weight was added to the right wing of 40 adult quail while the left wing in each bird served as an intra-animal control. The weight was removed after 30 days of stretch, and terminal experiments were conducted 0, 30, 60, or 90 days thereafter. Average slow beta-fiber area increased by 53.4 +/- 17.5% (SE) after 30 days of stretch, but it was not different from control area by 30 days poststretch removal. Total fiber number was determined after nitric acid digestion of connective tissue. It increased by 41.3 +/- 2.3% after 30 days of stretch, but it was 28.5 +/- 5.2% greater than control after unweighting for 30- days. Thus, once the overload was removed, fiber number returned to control levels more slowly than fiber mass or volume. The data suggest that mechanisms that downregulate fiber number and fiber size may differ in the ALD of the Japanese quail.

Muscle fiber formation and fiber hypertrophy during the onset of stretch-overload

1990 ◽  
Vol 259 (1) ◽  
pp. C92-C102 ◽  
Author(s):  
S. E. Alway ◽  
W. J. Gonyea ◽  
M. E. Davis
Keyword(s):  
Muscle Mass ◽  
Cross Sectional Area ◽  
Fiber Formation ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fiber Splitting ◽  
Anterior Latissimus Dorsi ◽  
Fiber Number ◽  
Nitric Acid Digestion ◽  
Animal Control

The contributions of fiber hypertrophy and new fiber formation to the onset of stretch-induced muscle enlargement were evaluated in the anterior latissimus dorsi (ALD) of adult Japanese quails, because it was not known whether the mechanisms which initiate new fiber formation were dependent on first achieving significant fiber hypertrophy. A weight corresponding to 10% of the bird's body mass was attached to one wing, and eight birds were killed after each day during the first week of stretch. Muscle mass was significantly increased after 48 h of stretch; however, the elevation in nonmuscle tissue accounted for this increase. Muscle mass corrected for non-muscle tissue was significantly greater than the intra-animal control by the fourth day of stretch. Mean fiber cross-sectional area did not change during days 0-6, but cross-sectional area was 30.0 +/- 17.2% greater than the intra-animal control areas at day 7. Fiber number determined after nitric acid digestion of connective tissue was 27.1 +/- 5.8% greater than the intra-animal control at days 5-7 of stretch, but the number of fibers in the control muscles at days 5 and 6 were lower than at day 0. Thus new fiber formation was not preceded by significant fiber hypertrophy. These results fail to support a mechanism for new fiber formation which involves fiber splitting from hypertrophied myofibers during the first week of stretch.

Role of muscle fiber hypertrophy and hyperplasia in intermittently stretched avian muscle

1993 ◽  
Vol 74 (4) ◽  
pp. 1893-1898 ◽  
Author(s):  
J. Antonio ◽  
W. J. Gonyea
Keyword(s):  
Muscle Fiber ◽  
Latissimus Dorsi ◽  
Histological Section ◽  
Volume Density ◽  
Left Wing ◽  
Avian Muscle ◽  
Anterior Latissimus Dorsi ◽  
Fiber Number ◽  
Equivalent Load ◽  
The Right

In the chronic stretch model, muscle fiber hyperplasia precedes fiber hypertrophy [Alway et al. Am. J. Physiol. 259 (Cell Physiol. 28): C92-C102, 1990]. This study was undertaken to determine if an intermittent stretch protocol would induce fiber hypertrophy without fiber hyperplasia. A weight equalt to 10% of the bird's mass was attached to the right wing of seven adult quail while the left wing served as the intra-animal control. The weight was attached to the wing for 24-h periods interspersed with a 48- to 72-hr rest interval. The actual stretch time was 5 days while the length of the treatment period was 15 days. Muscle mass and length increased significantly 53.1 +/- 9.0 and 26.1 +/- 7.3% in the stretched anterior latissimus dorsi. Fiber number, which was determined from a histological section in the midregion of the muscle, did not change (control 1,651.6 +/- 94.8; stretch 1,626.0 +/- 70.9). The slow tonic fiber areas increased significantly an average of 28.6 +/- 5.7%, whereas the fast fibers increased 18.5 +/- 8.4% when compared with control values. Mean fiber area (average of slow and fast fibers) increased significantly by 27.8 +/- 6.0% in the stretched anterior latissimus dorsi. There were no differences in the percentage of slow fibers or volume density of noncontractile tissue. These data indicate that muscle adapts differently to intermittent stretch than it does to chronic stretch despite an equivalent load and stretch duration. In contrast to chronic stretch, 5 days of intermittent stretch produces muscle fiber hypertrophy without fiber hyperplasia.

Effects of resistance training on elbow flexors of highly competitive bodybuilders

1992 ◽  
Vol 72 (4) ◽  
pp. 1512-1521 ◽  
Author(s):  
S. E. Alway ◽  
W. H. Grumbt ◽  
J. Stray-Gundersen ◽  
W. J. Gonyea
Keyword(s):  
Resistance Training ◽  
Training Program ◽  
Muscle Mass ◽  
Biceps Brachii ◽  
Fiber Type ◽  
Volume Density ◽  
Elbow Flexors ◽  
Cross Sectional ◽  
Fiber Number ◽  
Muscle Cross Sectional Area

The influence of gender on muscular adaptation of the elbow flexors to 24 wk of heavy resistance training was studied in five male bodybuilders (MB) and five female bodybuilders (FB) who were highly competitive. Muscle cross-sectional area (CSA), fiber area, and fiber number were determined from the biceps brachii, and voluntary elbow flexor torque was obtained at velocities of contraction between 0 and 300 degrees/s. Biceps and flexor CSA was 75.8 and 81% greater, respectively, in MB than in FB, but muscle CSA was not significantly altered by the training program in either group. Because estimated fiber number and the volume density of nonmuscle tissue were similar in MB and FB, most of the gender difference in muscle CSA appeared to be due to greater absolute mean fiber areas in MB (10.51 and 10.68 x 10(3) microns 2 pre- and posttraining, respectively) than in FB (5.33 and 5.96 x 10(3) microns 2 pre- and posttraining, respectively). In neither MB nor FB did fiber type achieve further hypertrophy during the 24-wk training program. These data suggest that the extent of any change in muscle mass or muscle fiber characteristics is minimal after a bodybuilder of either gender has attained a high degree of muscle mass and a highly competitive status.

scholarly journals Modern Forms of Populism and Social Policies: Personal Values, Populist Attitudes, and Ingroup Definitions in Support of Left-Wing and Right-Wing Welfare Policies in Italy

Genealogy ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 60
Author(s):  
Anna Miglietta ◽  
Barbara Loera
Keyword(s):  
Political Ideology ◽  
Online Survey ◽  
Personal Values ◽  
Theoretical Perspective ◽  
Right Wing ◽  
Left Wing ◽  
Welfare Policies ◽  
Political Ideologies ◽  
The Right ◽  
Cognitive Sophistication

We analyzed the relationship between modern forms of populism and citizen support for exclusive welfare policies and proposals, and we focused on support for left-wing- and right-wing-oriented welfare policies enacted or proposed during the Lega Nord (LN)–Five Star Movement (FSM) government in Italy (2018–2019). In light of the theoretical perspective of political ideology as motivated by social cognition, we examined citizens’ support for the two policies considering adherence to populist attitudes, agreement on the criteria useful to define ingroup membership, and personal values. We also took into account the role of cognitive sophistication in populism avoidance. A total of 785 Italian adults (F = 56.6; mean age = 35.8) completed an online survey in the summer of 2019 based on the following: support for populist policies and proposals, political ideologies and positioning, personal values, and ingroup boundaries. We used correlation and regression analyses. The results highlight the relationships between populism and political conservatism. Populism was related to the vertical and horizontal borders defining the “people”; cognitive sophistication was not a relevant driver. We identified some facilitating factors that could promote adherence to and support for public policies inspired by the values of the right or of the left, without a true ideological connotation.

scholarly journals A Plasmonic Refractive-Index Sensor Based Multiple Fano Resonance Multiplexing in Slot-Cavity Resonant System

2021 ◽  
Author(s):  
Zicong Guo ◽  
Kunhua Wen ◽  
Yuwen Qin ◽  
Yihong Fang ◽  
Zhengfeng Li ◽  
...  
Keyword(s):  
Fano Resonance ◽  
Fdtd Method ◽  
Rectangular Cavity ◽  
Refractive Index Sensor ◽  
Right Wing ◽  
Left Wing ◽  
Resonant System ◽  
Coupled Mode ◽  
Metal Insulator Metal ◽  
The Right

AbstractIn this paper, a sub-wavelength metal-insulator-metal (MIM) waveguide structure is proposed by using a cross-shape rectangular cavity, of which wings are coupled with two rectangular cavities. Firstly, a cross-shape rectangular cavity is placed between the input and output MIM waveguides. According to the mutual interference between bright and dark modes, three Fano resonant peaks are generated. Secondly, by adding a rectangular cavity on the left wing of the cross shaped one, five asymmetric Fano resonance peaks are obtained. Thirdly, six asymmetric Fano resonance peaks are achieved after adding another cavity on the right wing. Finally, the finite-difference-time-domain (FDTD) method and multimode interference coupled-mode theory (MICMT) are used to simulate and analyze the coupled plasmonic resonant system, respectively. The highest sensitivity of 1 000nm/RIU is achieved.

Regionalized adaptations and muscle fiber proliferation in stretch-induced enlargement

1989 ◽  
Vol 66 (2) ◽  
pp. 771-781 ◽  
Author(s):  
S. E. Alway ◽  
P. K. Winchester ◽  
M. E. Davis ◽  
W. J. Gonyea
Keyword(s):  
Muscle Fiber ◽  
Latissimus Dorsi ◽  
Volume Density ◽  
Cross Sectional ◽  
Adult Skeletal Muscle ◽  
Relative Contribution ◽  
Anterior Latissimus Dorsi ◽  
Fiber Number ◽  
Nitric Acid Digestion ◽  
Alpha Type

The relative contribution of increases in fiber area to stretch-induced muscle enlargement was evaluated in the slow tonic fibers of the anterior latissimus dorsi of adult Japanese quails. A weight corresponding to 10% of the bird's body mass was attached to one wing. Thirty days of stretch in 34 birds averaged 171.8 +/- 13.5% increase in muscle mass and 23.5 +/- 0.8% increase in muscle fiber length. The volume density of noncontractile tissue increased in middle and distal regions of stretch-enlarged muscles. Mean fiber cross-sectional area increased 56.7 +/- 12.3% in the midregion of stretched muscles. Further analysis indicated slow beta-fiber hypertrophy occurred in proximal, middle, and distal regions; however, fast alpha-type fiber hypertrophy was limited to middle regions of stretched muscles. Stretched muscles had a significant increase in the frequency of slow beta-fibers that were less than 500 microns 2 in all regions and fast alpha-type fibers in middle and distal regions. Total fiber number was determined after nitric acid digestion of connective tissue in 10 birds. Fiber number increased 51.8 +/- 19.4% in stretched muscle. These results are the first to clearly show that muscle fiber proliferation contributes substantially to adult skeletal muscle stretch-induced enlargement, although we do not know whether the responses of the slow tonic anterior latissimus dorsi might be similar or different from mammalian twitch muscle.

scholarly journals Rhythm Politics in a Changing Brazil: A Study of the Musical Mobilization of Voters by Bolsonaro and Haddad in the 2018 Election

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Kjetil Klette Bøhler
Keyword(s):  
Political Movements ◽  
Right Wing ◽  
Election Campaigns ◽  
Left Wing ◽  
Political Awareness ◽  
Public Events ◽  
Right Wing Populism ◽  
The Right ◽  
Musical Rhythms

This article investigates the role of music in presidential election campaigns and political movements inspired by theoretical arguments in Henri Lefebvre’s Rhythmanalysis, John Dewey ́s pragmatist rethinking of aesthetics and existing scholarship on the politics of music. Specifically, it explores how musical rhythms and melodies enable new forms of political awareness, participation, and critique in an increasingly polarized Brazil through an ethnomusicological exploration of how left-wing and right-wing movements used music to disseminate politics during the 2018 election that culminated in the presidency of Jair Messias Bolsonaro. Three lessons can be learned. First, in Brazil, music breathes life, energy, and affective engagement into politics—sung arguments and joyful rhythms enrich public events and street demonstrations in complex and dynamic ways. Second, music is used by right-wing and left-wing movements in unique ways. For Bolsonaro supporters and right-wing movements, jingles, produced as part of larger election campaigns, were disseminated through massive sound cars in the heart of São Paulo while demonstrators sang the national anthem and waved Brazilian flags. In contrast, leftist musical politics appears to be more spontaneous and bohemian. Third, music has the ability to both humanize and popularize bolsonarismo movements that threaten human rights and the rights of ethnic minorities, among others, in contemporary Brazil. To contest bolsonarismo, Trumpism, and other forms of extreme right-wing populism, we cannot close our ears and listen only to grooves of resistance and songs of freedom performed by leftists. We must also listen to the music of the right.

scholarly journals IDEOLOGI RADIKALISME DALAM ISLAM TENTANG WACANA HOMOSEKSUAL DI MEDIA MASSA

2018 ◽  
Vol 3 (2) ◽  
pp. 193
Author(s):  
Fita Fathurokhmah
Keyword(s):  
Mass Media ◽  
Human Being ◽  
Right Wing ◽  
Individual Freedom ◽  
Left Wing ◽  
Same Sex ◽  
The Media ◽  
The Mass Media ◽  
The Right ◽  
Ideological Difference

This article wants to examine how the media ideology about the concept of radicalism in Islam in the mass media of Republika and Koran Tempo. The Republika newspaper supports and agrees to the Islamic Defenders Front (FPI) both with an understanding of the prohibition of homosexuality and the appointment of news of FPI's violence against homosexuals. The Tempo newspaper is more about renewing ideas such as reporting on the views of the Liberal Islam Network (JIL) in respect of homosexuals. Homosexuality is the same sex lover or the choice of sexuality abnormalities is normal as a human being, it does not need to be criticized but must be respected as individual freedom. There is a fundamental ideological difference between Republika and Koran Tempo by renewing the concept of homosexuality with thinking radicalism on the basis of Islamic teachings. The homosexual issue, FPI applies the meaning of Islamic radicalism from the right-wing side which promotes violence as resistance, while JIL applies the meaning of radicalism from the left-wing side which prioritizes the radicalism of thought and law in the Koran.  AbstrakArtikel ini ingin mengkaji bagaimana ideologi media tentang konsep radikalisme dalam Islam di media massa Republika dan Koran Tempo. Surat kabar Republika mendukung dan setuju pada Front Pembela Islam (FPI) baik dengan pemahaman pelarangan homoseksual dan pengangkatan berita tindak kekerasan FPI melawan homoseksual. Koran Tempo lebih pada pembaharuan pemikiran seperti pemberitaan pandangan Jaringan Islam Liberal (JIL) terkait menghormatinya kaum homoseksual. Homoseksual adalah penyuka sesama jenis atau pilihan kelainan seksualitas itu normal sebagai manusia, tidak perlu dicela tapi harus dihargai sebagai kebebasan individu. Terdapat perbedaan ideologi yang mendasar antara Republika dan Koran Tempo dengan melakukan pembaharuan konsep homoseksual dengan radikalisme berpikir dengan pijakan ajaran Islam. Persoalan homoseksual, FPI menerapkan makna radikalisme Islam dari sisi sayap kanan yang mengedepankan kekerasan sebagai perlawanan, sedangkan JIL menerapkan makna radikalisme dari sisi sayap kiri yang mengutamakan keradikalan pemikiran dan hukum dalam al-Quran.

Sign in / Sign up

Export Citation Format

Share Document