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आयतन 1, मुद्दा 2 (2017)

शोध आलेख

Fossil and Living Cycads Say "No More Megasporophylls"

Xin Wang

The origins of angiosperms and cycads are still mysterious. To understand the evolution of these groups as well as other gymnosperms it was impossible without mentioning a frequently used term “megasporophyll”. “Megasporophyll” is a concept that has been used widely in botany. This term is more or less related with the famous saying “Alles ist Blatt” by Goethe. This term became popular since Arber and Parkin hypothesized that the carpels in the Magnoliales were equivalent to and derived from former foliar parts bearing ovules along their margins (“megasporophyll”). Many botanists uncritically called the parts in all the reproductive organs of seed plants as “sporophylls”, no matter what they actually saw in the plants. However, the fact is that none of the reproductive parts (fossil or living), except those in the Cycadales, are foliar or leaf-like. The female parts in (fossil and extant) Ginkgoales, Coniferales, and Gnetales apparently have nothing to do with any foliar parts, as proven by previous studies. Among the living gymnosperms, Cycadales usually are taken as the most primitive and ancestral, therefore understanding the reproductive organs and their evolution in Cycadales will not only enhance our understanding of Cycadales, but also is hinged with our understanding of all seed plants in general. Interestingly, the female parts of Cycadales are the ones that demonstrate by far the greatest resemblance to leaves, at least in appearance. Thus whether the female parts of Cycadales are truly foliar is a key but rarely asked question hinged with the validity of the term “megasporophyll” and the systematics of seed plants. To verify the validity of this term and its implications, we examined the morphology of both fossil and extant cycads. Our fossil evidence includes the earliest unequivocal fossil of cycad reproductive organ, Crossozamia chinensis (Zhu and Du) Gao and Thomas, recovered from the Permian of China. Unlike seen in living cycads, the ovules in this fossil reproductive organ are apparently inserted on the adaxial rather than strictly the laterals of the female parts. Such an arrangement is not expected for a typical leaf, but rather demonstrates certain resemblance to the sporangia arrangement in Archaeopteris. Parallel to and agreeing with this, the ovules in living cycads, Cycas taitungensis Shen, Hill, Tsou and Chen, have their micropyles oriented to the adaxial rather than the laterals of the parts. Taking into consideration of previous experiment proving that the leaf-like appearance of Cycas “megasporophylls” is due to mechanical pressure and unexpected occurrence of amphicribral vascular bundles with secondary growth in the so-called “megasporophylls” of cycads, we conclude that the female parts of these Cycadales are actually branches bearing ovules. This conclusion rejects foliar nature of female parts in cycads and undermines the validity of the term “megasporophylls”, although the latter has been the most-widely accepted misnomer in botany. The by-product of eliminating this term is that the origins of Cycadales and angiosperms as well as homology of carpels become much easier than assumed before. Considering the long time the term “megasporophyll” inflicting botany and misleading botanists, the influence of eliminating this misnomer in botany cannot be exaggerated. It is not restricted to a single term and its usage, but permeates into all branches of botany, especially the systematics of Cycadales, Angiosperms, and other seed plants.

समीक्षा लेख

Morphometric Surface Anatomy of the Pre and Postcentral Gyrus

Adel Hajjay M

Objective: This research was especially aimed to build the knowledge of surface anatomy regard the pre and post central gyrus with their bone relationships.
Methods: Ten Sudanese formalin-fixed adult heads (right and left sides) were used to evaluate the craniometric measurement of Pre and Post central gyrus of the cerebral hemisphere. Scalp was removed then the skull was marked as two windows by blue marker (Superior parietal window and Inferior parietal window) the blue marked lines were cut by autopsy electrical saw and the meninges were removed and the cerebral cortex was exposed. The pre and post central gyrus were measured from the nearest bony landmarks of coronal suture, sagittal suture and superior temporal line.
Results: Precentral gyrus superior part was measured from the coronal suture posteriorly at a point crossing the sagittal suture (right 4.10 ± 0.74 cm, left 4.12 ± 0.79 cm), Precentral gyrus inferior part was measured from the coronal suture posteriorly at a point crossing the superior temporal line (right 3.18 ± 0.67 cm, left 2.97 ± 0.76 cm), Postcentral gyrus superior part was measured from the coronal suture posteriorly at a point crossing the sagittal suture (right 5.32 ± 1.02 cm, left 5.22 ± 0.95 cm), Postcentral gyrus inferior part was measured from the coronal suture posteriorly at a point crossing the superior temporal line (right 4.64 ± 0.61 cm, left 4.31 ± 0.79 cm).
Conclusion: The research found that there were clear relations between the pre and post central gyrus with the cranial bony landmarks.

शोध आलेख

Anthropometrics Parameter and their Superior to Predict the Risks Pain Joints Associated with Body Weight among Sportswomen

Mohammed Z

Background: Newly, the A Body Shape Index (ABSI), hip index (HI) and anthropometric risk index (ARI) have been developed as a possible improved alternative to BMI and WC. While actual research aimed to exanimate the association between the anthropometrics parameter and their superior to predict the risks Pain Joints associated with body weight.
Methods: In order to achieve this goal, our total sample consisted of 40 women's soccer team of Relizane at the Algerian football championship, their homogeneity was drawn by age, sex, weight, height and football speciality, tested by Bearing-Sorensen and the Kelly test as a Lumbar Extensor Strength.
Results: Body types or shape index are a slight amount of lean body fat, however, waist circumference predicts the metabolic syndrome as a reduced joint range of motion.
Conclusion: Since ABSI is the ratio of human body shape to body size healthier prominent in the less body fat. While the body shape type may be considered as a proxy measure of fat distribution, seeing the waist circumference is a predictor for abnormal serum lipid and lipoproteins among Sudanese women. While among healthy sportswomen, our findings support larger WC as pear shape, risks increased body gain weight in the hips and thighs and health risk goes up as waist size increases.

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