scholarly journals Megalochelys: gigantic tortoise from the Neogene of Myanmar

2015 ◽  
Author(s):  
Ren Hirayama ◽  
Teppei Sonoda ◽  
Masanaru Takai ◽  
Thaung Htike ◽  
Zin Maung Maung Thein ◽  
...  
Keyword(s):  
Cervical Vertebra ◽  
Young Male ◽  
Distal Portion ◽  
Pectoral Girdle ◽  
Terrestrial Mammals ◽  
Male Individual ◽  
Original Length ◽  
Lower Pleistocene ◽  
Narrow Area ◽  
Maximum Shell Length

Background. The genus Megalochelys is the largest known testudinid (family Testudnidae) found from the upper Miocene to lower Pleistocene of India to Indonesian Islands. The maximum length of the shell in this genus has been estimated as up to about 2 m long based on a specimen from the lower Pleistocene of Java Island, Indonesia. Recently, joint paleontological expeditions of Japan and Myanmar led by M. Takai have unearthed abundant fossils of this genus from the Neogene since 2003. These materials shed new light on this unique gigantic tortoise. Methods. All materials of Megalochelys were found from the Lower Irrawaddy Beds in poor preservation except for one nearly complete shell. The shell lengths from the fragmentary materials were estimated by using those of medium to large–sized testudinids. Results. Postcranial materials, including twenty-five epiplastra, one cervical vertebra, appendicular skeletons, and one nearly complete shell (about 180 cm long) have been discovered from the Lower Irrawaddy Beds in narrow area near Pauk Township. They are associated with terrestrial mammals such as Stegodon, suggesting that the age of the fossil bearing beds are attributed to the late Miocene to the early Pliocene. Of these, the epiplastra in two morphological states appear to be derived from sexual dimorphism of this genus as seen in several testudinids and noted previously by second author on the relevant materials. A huge distal portion of the humerus (ca. 31 cm long) suggests that its original length was about 75 cm. Discussion. A nearly complete shell is about 180 cm long, although this seems a rather young male individual of Megalochelys based on its rather slender epiplastral morphology, which is nearly as large as given estimation of the maximum shell length from Java material. On the other hand, the largest humerus, estimated as 75 cm in original length, suggests its shell was about 270 cm long. This estimation seems to be supported by other isolated materials such as the nuchal plate, largest epiplastron, and the pectoral girdle. Hitherto, Stupendemys geographica (from the Pliocene of Venezuela) and Archelon ischyros (from the Lower Cretaceous of North America) were regarded as largest known turtles with about 220 cm long shell. However, Megalochelys from Myanmar involves much larger specimens, suggesting this is a true largest known turtle.

scholarly journals Megalochelys: gigantic tortoise from the Neogene of Myanmar

2015 ◽  
Author(s):  
Ren Hirayama ◽  
Teppei Sonoda ◽  
Masanaru Takai ◽  
Thaung Htike ◽  
Zin Maung Maung Thein ◽  
...  
Keyword(s):  
Cervical Vertebra ◽  
Young Male ◽  
Distal Portion ◽  
Pectoral Girdle ◽  
Terrestrial Mammals ◽  
Male Individual ◽  
Original Length ◽  
Lower Pleistocene ◽  
Narrow Area ◽  
Maximum Shell Length

Background. The genus Megalochelys is the largest known testudinid (family Testudnidae) found from the upper Miocene to lower Pleistocene of India to Indonesian Islands. The maximum length of the shell in this genus has been estimated as up to about 2 m long based on a specimen from the lower Pleistocene of Java Island, Indonesia. Recently, joint paleontological expeditions of Japan and Myanmar led by M. Takai have unearthed abundant fossils of this genus from the Neogene since 2003. These materials shed new light on this unique gigantic tortoise. Methods. All materials of Megalochelys were found from the Lower Irrawaddy Beds in poor preservation except for one nearly complete shell. The shell lengths from the fragmentary materials were estimated by using those of medium to large–sized testudinids. Results. Postcranial materials, including twenty-five epiplastra, one cervical vertebra, appendicular skeletons, and one nearly complete shell (about 180 cm long) have been discovered from the Lower Irrawaddy Beds in narrow area near Pauk Township. They are associated with terrestrial mammals such as Stegodon, suggesting that the age of the fossil bearing beds are attributed to the late Miocene to the early Pliocene. Of these, the epiplastra in two morphological states appear to be derived from sexual dimorphism of this genus as seen in several testudinids and noted previously by second author on the relevant materials. A huge distal portion of the humerus (ca. 31 cm long) suggests that its original length was about 75 cm. Discussion. A nearly complete shell is about 180 cm long, although this seems a rather young male individual of Megalochelys based on its rather slender epiplastral morphology, which is nearly as large as given estimation of the maximum shell length from Java material. On the other hand, the largest humerus, estimated as 75 cm in original length, suggests its shell was about 270 cm long. This estimation seems to be supported by other isolated materials such as the nuchal plate, largest epiplastron, and the pectoral girdle. Hitherto, Stupendemys geographica (from the Pliocene of Venezuela) and Archelon ischyros (from the Lower Cretaceous of North America) were regarded as largest known turtles with about 220 cm long shell. However, Megalochelys from Myanmar involves much larger specimens, suggesting this is a true largest known turtle.

Assembly and function of Chlamydomonas flagellar mastigonemes as probed with a monoclonal antibody

1996 ◽  
Vol 109 (1) ◽  
pp. 57-62 ◽  
Author(s):  
S. Nakamura ◽  
G. Tanaka ◽  
T. Maeda ◽  
R. Kamiya ◽  
T. Matsunaga ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Beat Frequency ◽  
Distal Portion ◽  
Distal Region ◽  
Ring Structure ◽  
Live Cells ◽  
Swimming Velocity ◽  
Flagellar Beat ◽  
Original Length ◽  
And Function

Mastigonemes are hair-like projections on the flagella of various kinds of lower eukaryotes. We obtained a monoclonal antibody (mAb-MAST1) to mastigonemes of Chlamydomonas reinhardtii, and found that it reacts with a single flagellar glycoprotein of about 230 kDa. Interestingly, immunofluorescence microscopy demonstrated that mAb-MAST1 recognizes not only the flagellar mastigonemes but also a ring composed of 10 or more particles located in the anterior end of the cell body close to the flagellar bases. The ring structure may be the pool of the mastigoneme protein. When the flagella are amputated, they regenerate to their original length in 90–120 minutes. We found that mastigonemes appear on the new flagellar surface as early as 15 minutes after deflagellation, and that new mastigonemes are mostly assembled onto the distal region of the flagellar surface. Mastigonemes thus appear to be inserted into the membrane only in the distal region of the flagellum. Alternatively, mastigonemes may be inserted at the base and transported very rapidly to the distal portion where they are trapped. When live cells are treated with mAb-MAST1, mastigonemes disappear from the flagellar surface. In these mAb-MAST1 treated cells, the swimming velocity decreases to 70–80% of the normal value, although the flagellar beat frequency increases to approximately 110% of the control. These findings demonstrate vectorial transport of mastigonemes to their assembly sites, and show that mastigonemes function to increase flagellar propulsive force by increasing the effective surface of the flagellum.

scholarly journals A case of myositis ossificans traumatica on one skeleton from Viminacium

Starinar ◽  
2019 ◽  
pp. 203-214
Author(s):  
Dragana Vulovic ◽  
Natasa Miladinovic-Radmilovic ◽  
Ilija Mikic
Keyword(s):  
Muscle Tissue ◽  
Late Antiquity ◽  
Myositis Ossificans ◽  
Young Male ◽  
North East ◽  
Male Individual ◽  
Military Camp ◽  
Post Traumatic ◽  
The Right ◽  
Myositis Ossificans Circumscripta

The Roman city and military camp of Viminacium is situated between the villages of Stari Kostolac and Drmno, 12 kilometres north-east of Pozarevac, close to the confluence of the Mlava and the Danube. During its history, it became the biggest urban settlement and the capital of the province of Upper Moesia (Moesia Superior), later First Moesia (Moesia Prima). In one of the necropoles of Viminacium, Pecine, in grave No. 5785, skeletal remains of a juvenile male individual were discovered. The burial took place in Late Antiquity. Anthropological analyses revealed a fracture of the right femur followed by myositis ossificans traumatica. The trauma to the bone can damage the overlying muscle and, occasionally, the muscle tissue will respond to the trauma by producing bone directly in the muscle tissue itself. This condition is known as myositis ossificans traumafica (post-traumatic myositis ossificans or myositis ossificans circumscripta) and is most likely to occur in response to trauma in young male individuals, and in the femoral (the quadriceps muscles) or humeral region (brachium muscles).

Ultrastructural Study of Human Testicular Biopsies in Infertility

1976 ◽  
Vol 34 ◽  
pp. 156-157
Author(s):  
Shirley Siew ◽  
Philip Troen ◽  
Howard R. Nankin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basement Membrane ◽  
Leydig Cells ◽  
Clinical Evidence ◽  
Young Male ◽  
Germinal Epithelium ◽  
Transmission Electron ◽  
Age Range ◽  
Male Subjects

Testicular biopsies were obtained from six young male subjects (age range 24-33) who complained of infertility and who had clinical evidence of oligospermia. This was confirmed on histological examination which showed a broad spectrum from profound hypospermatogenesis to relatively normal appearing germinal epithelium. Thickening of the tubular walls was noted in half of the cases and slight peritubular fibrosis in one. The Leydig cells were reported as normal or unremarkable.Transmission electron microscopy showed that the thickening of the supporting tissue of the germinal epithelium was caused more by an increase in the thickness of the layers of the lamina propria than of the tubular wall itself. The changes in the basement membrane of the tubular wall consisted mostly of a greater degree of infolding into the tubule and some reduplication which gave rise to a multilayered appearance.

Remission of Recurrent Cochlear Hydrops Associated With Bromocriptine Treatment for Macroprolactinoma

2019 ◽  
Vol 28 (3) ◽  
pp. 548-552
Author(s):  
Andro Košec ◽  
Ivan Kruljac ◽  
Jakov Ajduk
Keyword(s):  
Dopamine Receptors ◽  
Male Patient ◽  
Endolymphatic Hydrops ◽  
Young Male ◽  
Oral Steroid ◽  
Case Description ◽  
Diuretic Treatment ◽  
Potential Therapeutic Role ◽  
Transient Improvement ◽  
Systemic Glucocorticoids

Objective Current recommendations for cochlear hydrops treatment include systemic glucocorticoids and diuretics. Cochlear cells express dopamine receptors, although their role is unknown in the pathophysiology of cochlear hydrops. Case Description We report the case of remission of recurrent right-sided cochlear hydrops in a young male patient treated with bromocriptine due to pituitary macroprolactinoma. Transient improvement was observed after oral steroid and diuretic treatment, but cochlear hydrops recurred until the dose of bromocriptine was increased to 10 mg daily. Conclusion Bromocriptine may stimulate dopamine receptors in cochlear cells with potential therapeutic role in patients with cochlear hydrops. There are no widely accepted and effective treatments for endolymphatic hydrops, and identifying potential new and efficacious therapeutics is of high relevance.

Abstract #1011: Galactorrhoea in a Young Male

2016 ◽  
Vol 22 ◽  
pp. 233
Author(s):  
Sachin Jain ◽  
Mahender Rajput ◽  
Anshuman Srivastava ◽  
Ramesh Aggarwal ◽  
Subodh Gururani ◽  
...  
Keyword(s):  
Young Male

Abstract #555 Parathyroid Crisis in a Young Male

2018 ◽  
Vol 24 ◽  
pp. 137-138
Author(s):  
Jahnavi Chakrala ◽  
Syed-azhar Hassan ◽  
Ayesha Siddiqui ◽  
Ramachandra Rahul Chemitiganti ◽  
James Burks
Keyword(s):  
Young Male

Young male drivers. Impulse expression, accidents, and violations

JAMA ◽  
1967 ◽  
Vol 200 (12) ◽  
pp. 1026-1030 ◽  
Author(s):  
S. H. Schuman
Keyword(s):  
Young Male

Effects of Antioxidant Supplementation and Exercise Training on Erythrocyte Antioxidant Enzymes

2006 ◽  
Vol 76 (5) ◽  
pp. 324-331 ◽  
Author(s):  
Marsh ◽  
Laursen ◽  
Coombes
Keyword(s):  
Antioxidant Enzymes ◽  
Exercise Training ◽  
Endurance Training ◽  
Young Male ◽  
Antioxidant Defenses ◽  
Antioxidant Enzyme Activities ◽  
Antioxidant Supplementation ◽  
Male Wistar Rats ◽  
Exercise Induced ◽  
Antioxidant Supplements

Erythrocytes transport oxygen to tissues and exercise-induced oxidative stress increases erythrocyte damage and turnover. Increased use of antioxidant supplements may alter protective erythrocyte antioxidant mechanisms during training. Aim of study: To examine the effects of antioxidant supplementation (α-lipoic acid and α-tocopherol) and/or endurance training on the antioxidant defenses of erythrocytes. Methods: Young male Wistar rats were assigned to (1) sedentary; (2) sedentary and antioxidant-supplemented; (3) endurance-trained; or (4) endurance-trained and antioxidant-supplemented groups for 14 weeks. Erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) activities, and plasma malondialdehyde (MDA) were then measured. Results: Antioxidant supplementation had no significant effect (p > 0.05) on activities of antioxidant enzymes in sedentary animals. Similarly, endurance training alone also had no effect (p > 0.05). GPX (125.9 ± 2.8 vs. 121.5 ± 3.0 U.gHb–1, p < 0.05) and CAT (6.1 ± 0.2 vs. 5.6 ± 0.2 U.mgHb–1, p < 0.05) activities were increased in supplemented trained animals compared to non-supplemented sedentary animals whereas SOD (61.8 ± 4.3 vs. 52.0 ± 5.2 U.mgHb–1, p < 0.05) activity was decreased. Plasma MDA was not different among groups (p > 0.05). Conclusions: In a rat model, the combination of exercise training and antioxidant supplementation increased antioxidant enzyme activities (GPX, CAT) compared with each individual intervention.

Reaction Time and Brain Waves in Omitted Stimulus Tasks

2010 ◽  
Vol 24 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Oscar H. Hernández ◽  
Muriel Vogel-Sprott
Keyword(s):  
Reaction Time ◽  
Cognitive Processes ◽  
Young Male ◽  
Event Related Potential ◽  
Auditory Stimuli ◽  
Motor Action ◽  
Cognitive Component ◽  
Sensory Modalities ◽  
Two Measures ◽  
Somatosensory Stimuli

A missing stimulus task requires an immediate response to the omission of a regular recurrent stimulus. The task evokes a subclass of event-related potential known as omitted stimulus potential (OSP), which reflects some cognitive processes such as expectancy. The behavioral response to a missing stimulus is referred to as omitted stimulus reaction time (RT). This total RT measure is known to include cognitive and motor components. The cognitive component (premotor RT) is measured by the time from the missing stimulus until the onset of motor action. The motor RT component is measured by the time from the onset of muscle action until the completion of the response. Previous research showed that RT is faster to auditory than to visual stimuli, and that the premotor of RT to a missing auditory stimulus is correlated with the duration of an OSP. Although this observation suggests that similar cognitive processes might underlie these two measures, no research has tested this possibility. If similar cognitive processes are involved in the premotor RT and OSP duration, these two measures should be correlated in visual and somatosensory modalities, and the premotor RT to missing auditory stimuli should be fastest. This hypothesis was tested in 17 young male volunteers who performed a missing stimulus task, who were presented with trains of auditory, visual, and somatosensory stimuli and the OSP and RT measures were recorded. The results showed that premotor RT and OSP duration were consistently related, and that both measures were shorter with respect to auditory stimuli than to visual or somatosensory stimuli. This provides the first evidence that the premotor RT is related to an attribute of the OSP in all three sensory modalities.

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