Jollyanna Malavasi | Universidad de Costa Rica (original) (raw)
Papers by Jollyanna Malavasi
PubMed, Jul 1, 1980
The ultrastructure of adult hamster (Mesocricetus auratus) testis was studied by means of light a... more The ultrastructure of adult hamster (Mesocricetus auratus) testis was studied by means of light and electron microscopes during fourteen months after bilateral vasectomy. In all the vasectomized animals there was marked degeneration of the semniiferous tubules as well as reduction of spermatogenesis. The thickening of the basal membrane was quite evident and showed extensive infolding. In the Sertoli cells, the presence of spherical or oval membrane-bound granules, vacuoles and degenerating cytoplasmic organelles were observed in the vasectomized group. Degenerative changes of sub-cellular organelles were quite evident in the process of spermatogenesis and spermiogenesis. The number of spermatogonia, spermatocytes, spermatids and mature sperms were considerably reduced; in some cases, almost completely degenerated. Only one type of spermatogonia (Type A) remained intact in the germinal epithelium. Large numbers of multi-nucleate spermatids were observed eight months after vasectomy. These cells were identifiable at all stages of spermatogenesis but were readily detected in cap phase spermatids. There was no evidence of any regeneration occurring in the seminferous tubules examined eight months after vasectomy.
Revista de biología tropical, 1981
Electron microscopy studies on the epididymal epithelium and lumen contents of hamster between 3 ... more Electron microscopy studies on the epididymal epithelium and lumen contents of hamster between 3 and 14 months after vasectomy, showed ultrastructural changes in the clear cells and spermatozoids within the lumen. These changes on the clear cells were as follows: accumulation of electron dense bodies of irregular forms distributed between luminal and basal zones of clear cells, presence of large vacuoles of low electron density and a loss of stereocilia; flattening of luminal border and emission of projections toward the lumen. Spermatozoid population was low within the lumen and is accompanied by large amounts of detritic material. Most of the gametes were destroyed. A variety of abnormal forms of spermatids were observed in advanced maturation stage.
Journal of Electron Microscopy, 1986
International Journal of Acarology, 1991
Contrary to common belief, the authors suggest that the ambulacrum of the adult females Varroa, E... more Contrary to common belief, the authors suggest that the ambulacrum of the adult females Varroa, Euvarroa and probably of Tropilaelaps is not a sucker or a sticky pad but a structure with protractile claw-like sclerites as shown by SEM analysis. These claw-like sclerites may work as crochets to grasp the hairs of the bee and allow the mites to move
Cancer research, 1986
Detailed ultrastructure of a new type of retrovirus (Sm-MTV) released by cultured cells (Sm-MT) o... more Detailed ultrastructure of a new type of retrovirus (Sm-MTV) released by cultured cells (Sm-MT) of a spontaneous mammary tumor from a house musk shrew Suncus murinus, Insectivora, is described. The virus particles were revealed as three forms: intracellular; budding; and extracellular. The intracellular type A particles were similar in profile to those associated with mouse mammary tumor cells and tended to form a small cluster of several particles in the cytoplasm. In addition, horseshoe-shaped particles as well as smaller particles in clusters, with doughnut-shaped morphology similar in structure to type A particles, were identified near the clusters of type A particles, although in smaller numbers. The budding particles contained a doughnut-shaped nucleoid, although the nucleoids decreased in size as compared with intracytoplasmic type A particles. The extracellular virions consisted of an envelope and a centrally located nucleoid. In routinely fixed specimens, the former was cov...
Journal of Electron Microscopy, 1985
Ultrastructure of a new type of intracisternal virus-like particles (Mol-P) found in a subcutaneo... more Ultrastructure of a new type of intracisternal virus-like particles (Mol-P) found in a subcutaneous tumor from a Japanese wild mouse, Mus musculus molossinus, was described. Mol-Ps were observed in two forms: as budding particles at the membrane of the rough endoplasmic reticulum (r-er) and as free particles, 120 nm in average diameter, in the dsternae. The envelopes of budding forms were continuous with the r-er membrane and each contained a small dense core, 45 nm in average diameter. The free forms were round, oval, or pearshaped, and were bounded by an envelope with a unit membrane structure. Different from the coexisting Intracisternal A particles identical in profile to those reported previously, the free forms were characterized by the presence of an eccentrically located nucleold. The nucleoid consisted of a small dense core surrounded by an intermediate membranous structure (IMS) about 5 nm thick. The IMS displayed either a closed-circular structure or a whirled, open-circular profile. Tn the latter IMS, one end was terminated at the envelope and the other at the core. Possible origins of Mol-P were discussed in relation to known retrovlruses.
Applied Energy, 2021
Abstract Electric power system reform and innovative energy transaction policies have become incr... more Abstract Electric power system reform and innovative energy transaction policies have become increasingly common. In view of the fact that research on today’s multi-energy coupled market have not yet incorporated multi-energy substitution characteristics on the supply and demand sides, nor the coordination between regional and user level markets. A joint energy market was developed in this study for the procurement of local integrated energy system services considering demand flexibility. The transaction mechanisms of the regional level energy coupled market and user level Peer-to-Peer (P2P) distributed transaction market were determined accordingly. The multi-energy and complementary regional energy market was coupled with the user-level distributed transaction market that considering flexible demand response characteristics to establish a regional integrated energy system joint market. The electricity, gas, and heat markets in the regional market were modeled separately, then a joint clearing mechanism of the energy coupled market was established. An autonomous scheduling model for distributed market participants at the user level and a P2P transaction mechanism considering multi-agent non-cooperative game was proposed. The bidding behaviors of different energy operators in the regional level market were simulated to assess the influencing factors. The economic and technical benefits of P2P transactions at the user level as remitted to market participants were quantitatively determined with specific indexes. The correlations and interactions between the region level and user level markets were also analyzed.
Revista De Biologia Tropical, 1981
Surface ultrastructures of the digestive tracts of Taeniopoda and Schistocerca were studied by sc... more Surface ultrastructures of the digestive tracts of Taeniopoda and Schistocerca were studied by scanning electron microscopy and the surface of the pharynx, esophagus, crop, cardiac valve, stomach, ileum, colon and rectum are described. Clear structural differences were observed in each part of the digestive tracts in the two genera. The epithelial cell of the pharynx and esophagus showed well developed infolding and conical projections in both genera, however, the epithelial cell structure of Schistocerca is much more convex. In Schistocerca the overall structure is more mosaic-like, with three conical projections for each unit. In both genera the transitional zone between the crop and the stomach is formed by well developed triangles and the stomach and caecum have abundant infoldings and microvilli. The ileum shows abundant cone-shaped projections; the colon and rectal sac are smooth.
The ultrastructure of adult hamster ( Mesocricetus auratus ) testis was studied by means of light... more The ultrastructure of adult hamster ( Mesocricetus auratus ) testis was studied by means of light and electron microscopes during fourteen months after bilateral vasectomy. In all the vasectomized animals there was marked degeneration of the seminiferous tubules as well as reduction of spermatogenesis. The thickening of the basal membrane was quite evident and showed extensive infolding. In the Sertoli cells, the presence of spherical or oval membrane-bound granules, vacuoles and degenerating cytoplasmic organelles were observed in the vasectomized group. Degenerative changes of sub-cellular organelles were quite evident in the process of spermatogenesis and spermiogenesis. The number of spermatogonia, spermatocytes, spermatids and mature sperms were considerably reduced; in some cases, almost completely degenerated. Only one type of spermatogonia (Type A) remained intact in the germinal epithelium. Large numbers of multi-nucleate spermatids were observed eight months after vasectom...
Pollination of the pistillate fig flowers (Ficus spp.) has crucial effects for the figs and the p... more Pollination of the pistillate fig flowers (Ficus spp.) has crucial effects for the figs and the pollinating wasps (Agaonidae). It a1lows nonnal development, of seeds and wasps. Sorne agaonid groups have evolved pockets and corbiculae to carry pollen, wlule others carry it in the intersegmental membranes and other hidden areas of the body. Single female specimens of Pleistodontes rieki Wiebes, Robertsia mandibularis Boucek, Tetrapus americanus Mayr and Tetrapus sp., the first two from New Guinea and theTetrapus spp. from Costa Rica were studied with scanning electron microscopy. Sorne Pleistodontes species (Old World) have pollen cavities in the expanded scapes; theyalso carry pollen in the ridges and laminae of the mandib1es. Tetrapus species (New World) carry pollen in cavities located behind the mandibular appendages and in the lamellae, ridges and teeth of the mandibles. These ways of carrying pollen may be intennediate between pollen transport in the intersegmental membranes, an...
An ultrastructural description of the pharynx, esophagus, crop, gizzard, gastric caeca, stomach, ... more An ultrastructural description of the pharynx, esophagus, crop, gizzard, gastric caeca, stomach, hind intestine and rectal sac of Gryllus sp. was performed under scanning electronic microscopy. Both the pharynx and the esophagus present an epithelium formed by overlapping sheets containing several thorn-like projections. The crop shows transversal and longitudinal creases and is covered by the same type of overlapping sheets found on the pharynx and the esophagus. The most complex fine structure was observed in the gizzard. This part shows a very irregular epithelium where four different sub units are distinguished, which together conform the characteristic units of this species. The fine structure of the epithelium, of the stomach and gastric caeca is very homogeneous, downy, velvet-like, due to the millions of fine hairs that totally cover this zone of the tract. The intestinal digestive epithelium is very smooth and at the large intestine level it shows some conic prominences.
Virology, 1985
A new type of retrovirus (Sm-MTV) released by cultured cells of a spontaneous mammary tumor from ... more A new type of retrovirus (Sm-MTV) released by cultured cells of a spontaneous mammary tumor from a house musk shrew, Suncus murinus, is described. The Sm-MTV is distinct morphologically from type C particles. In spite of certain morphological similarities to type B and type D retroviruses, the Sm-MTV is readily distinguishable. The extracellular virions had a spikeless envelope containing a centrally located nucleoid with a small electron-dense core surrounded by an inner membrane. The budding particles contained a doughnut-shaped nucleoid. Intracytoplasmic type A particles similar in profile to those associated with mouse mammary tumor cells were also found, and tended to form a small cluster of several particles in the cytoplasm. The virus banded at 1.169 g/cm3 in isopycnic centrifugation and possessed constitutive Mg2+-dependent reverse transcriptase. The viral RNA had a molecular size ranging from 50 to 70 S in its native form and 30 to 40 S in its denatured form by a glycerol gradient ultracentrifugation. Major viral polypeptides were 72K, 69K, 47K, 44K/43K, 27K, 20.5K, and 15K.
PubMed, Jul 1, 1980
The ultrastructure of adult hamster (Mesocricetus auratus) testis was studied by means of light a... more The ultrastructure of adult hamster (Mesocricetus auratus) testis was studied by means of light and electron microscopes during fourteen months after bilateral vasectomy. In all the vasectomized animals there was marked degeneration of the semniiferous tubules as well as reduction of spermatogenesis. The thickening of the basal membrane was quite evident and showed extensive infolding. In the Sertoli cells, the presence of spherical or oval membrane-bound granules, vacuoles and degenerating cytoplasmic organelles were observed in the vasectomized group. Degenerative changes of sub-cellular organelles were quite evident in the process of spermatogenesis and spermiogenesis. The number of spermatogonia, spermatocytes, spermatids and mature sperms were considerably reduced; in some cases, almost completely degenerated. Only one type of spermatogonia (Type A) remained intact in the germinal epithelium. Large numbers of multi-nucleate spermatids were observed eight months after vasectomy. These cells were identifiable at all stages of spermatogenesis but were readily detected in cap phase spermatids. There was no evidence of any regeneration occurring in the seminferous tubules examined eight months after vasectomy.
Revista de biología tropical, 1981
Electron microscopy studies on the epididymal epithelium and lumen contents of hamster between 3 ... more Electron microscopy studies on the epididymal epithelium and lumen contents of hamster between 3 and 14 months after vasectomy, showed ultrastructural changes in the clear cells and spermatozoids within the lumen. These changes on the clear cells were as follows: accumulation of electron dense bodies of irregular forms distributed between luminal and basal zones of clear cells, presence of large vacuoles of low electron density and a loss of stereocilia; flattening of luminal border and emission of projections toward the lumen. Spermatozoid population was low within the lumen and is accompanied by large amounts of detritic material. Most of the gametes were destroyed. A variety of abnormal forms of spermatids were observed in advanced maturation stage.
Journal of Electron Microscopy, 1986
International Journal of Acarology, 1991
Contrary to common belief, the authors suggest that the ambulacrum of the adult females Varroa, E... more Contrary to common belief, the authors suggest that the ambulacrum of the adult females Varroa, Euvarroa and probably of Tropilaelaps is not a sucker or a sticky pad but a structure with protractile claw-like sclerites as shown by SEM analysis. These claw-like sclerites may work as crochets to grasp the hairs of the bee and allow the mites to move
Cancer research, 1986
Detailed ultrastructure of a new type of retrovirus (Sm-MTV) released by cultured cells (Sm-MT) o... more Detailed ultrastructure of a new type of retrovirus (Sm-MTV) released by cultured cells (Sm-MT) of a spontaneous mammary tumor from a house musk shrew Suncus murinus, Insectivora, is described. The virus particles were revealed as three forms: intracellular; budding; and extracellular. The intracellular type A particles were similar in profile to those associated with mouse mammary tumor cells and tended to form a small cluster of several particles in the cytoplasm. In addition, horseshoe-shaped particles as well as smaller particles in clusters, with doughnut-shaped morphology similar in structure to type A particles, were identified near the clusters of type A particles, although in smaller numbers. The budding particles contained a doughnut-shaped nucleoid, although the nucleoids decreased in size as compared with intracytoplasmic type A particles. The extracellular virions consisted of an envelope and a centrally located nucleoid. In routinely fixed specimens, the former was cov...
Journal of Electron Microscopy, 1985
Ultrastructure of a new type of intracisternal virus-like particles (Mol-P) found in a subcutaneo... more Ultrastructure of a new type of intracisternal virus-like particles (Mol-P) found in a subcutaneous tumor from a Japanese wild mouse, Mus musculus molossinus, was described. Mol-Ps were observed in two forms: as budding particles at the membrane of the rough endoplasmic reticulum (r-er) and as free particles, 120 nm in average diameter, in the dsternae. The envelopes of budding forms were continuous with the r-er membrane and each contained a small dense core, 45 nm in average diameter. The free forms were round, oval, or pearshaped, and were bounded by an envelope with a unit membrane structure. Different from the coexisting Intracisternal A particles identical in profile to those reported previously, the free forms were characterized by the presence of an eccentrically located nucleold. The nucleoid consisted of a small dense core surrounded by an intermediate membranous structure (IMS) about 5 nm thick. The IMS displayed either a closed-circular structure or a whirled, open-circular profile. Tn the latter IMS, one end was terminated at the envelope and the other at the core. Possible origins of Mol-P were discussed in relation to known retrovlruses.
Applied Energy, 2021
Abstract Electric power system reform and innovative energy transaction policies have become incr... more Abstract Electric power system reform and innovative energy transaction policies have become increasingly common. In view of the fact that research on today’s multi-energy coupled market have not yet incorporated multi-energy substitution characteristics on the supply and demand sides, nor the coordination between regional and user level markets. A joint energy market was developed in this study for the procurement of local integrated energy system services considering demand flexibility. The transaction mechanisms of the regional level energy coupled market and user level Peer-to-Peer (P2P) distributed transaction market were determined accordingly. The multi-energy and complementary regional energy market was coupled with the user-level distributed transaction market that considering flexible demand response characteristics to establish a regional integrated energy system joint market. The electricity, gas, and heat markets in the regional market were modeled separately, then a joint clearing mechanism of the energy coupled market was established. An autonomous scheduling model for distributed market participants at the user level and a P2P transaction mechanism considering multi-agent non-cooperative game was proposed. The bidding behaviors of different energy operators in the regional level market were simulated to assess the influencing factors. The economic and technical benefits of P2P transactions at the user level as remitted to market participants were quantitatively determined with specific indexes. The correlations and interactions between the region level and user level markets were also analyzed.
Revista De Biologia Tropical, 1981
Surface ultrastructures of the digestive tracts of Taeniopoda and Schistocerca were studied by sc... more Surface ultrastructures of the digestive tracts of Taeniopoda and Schistocerca were studied by scanning electron microscopy and the surface of the pharynx, esophagus, crop, cardiac valve, stomach, ileum, colon and rectum are described. Clear structural differences were observed in each part of the digestive tracts in the two genera. The epithelial cell of the pharynx and esophagus showed well developed infolding and conical projections in both genera, however, the epithelial cell structure of Schistocerca is much more convex. In Schistocerca the overall structure is more mosaic-like, with three conical projections for each unit. In both genera the transitional zone between the crop and the stomach is formed by well developed triangles and the stomach and caecum have abundant infoldings and microvilli. The ileum shows abundant cone-shaped projections; the colon and rectal sac are smooth.
The ultrastructure of adult hamster ( Mesocricetus auratus ) testis was studied by means of light... more The ultrastructure of adult hamster ( Mesocricetus auratus ) testis was studied by means of light and electron microscopes during fourteen months after bilateral vasectomy. In all the vasectomized animals there was marked degeneration of the seminiferous tubules as well as reduction of spermatogenesis. The thickening of the basal membrane was quite evident and showed extensive infolding. In the Sertoli cells, the presence of spherical or oval membrane-bound granules, vacuoles and degenerating cytoplasmic organelles were observed in the vasectomized group. Degenerative changes of sub-cellular organelles were quite evident in the process of spermatogenesis and spermiogenesis. The number of spermatogonia, spermatocytes, spermatids and mature sperms were considerably reduced; in some cases, almost completely degenerated. Only one type of spermatogonia (Type A) remained intact in the germinal epithelium. Large numbers of multi-nucleate spermatids were observed eight months after vasectom...
Pollination of the pistillate fig flowers (Ficus spp.) has crucial effects for the figs and the p... more Pollination of the pistillate fig flowers (Ficus spp.) has crucial effects for the figs and the pollinating wasps (Agaonidae). It a1lows nonnal development, of seeds and wasps. Sorne agaonid groups have evolved pockets and corbiculae to carry pollen, wlule others carry it in the intersegmental membranes and other hidden areas of the body. Single female specimens of Pleistodontes rieki Wiebes, Robertsia mandibularis Boucek, Tetrapus americanus Mayr and Tetrapus sp., the first two from New Guinea and theTetrapus spp. from Costa Rica were studied with scanning electron microscopy. Sorne Pleistodontes species (Old World) have pollen cavities in the expanded scapes; theyalso carry pollen in the ridges and laminae of the mandib1es. Tetrapus species (New World) carry pollen in cavities located behind the mandibular appendages and in the lamellae, ridges and teeth of the mandibles. These ways of carrying pollen may be intennediate between pollen transport in the intersegmental membranes, an...
An ultrastructural description of the pharynx, esophagus, crop, gizzard, gastric caeca, stomach, ... more An ultrastructural description of the pharynx, esophagus, crop, gizzard, gastric caeca, stomach, hind intestine and rectal sac of Gryllus sp. was performed under scanning electronic microscopy. Both the pharynx and the esophagus present an epithelium formed by overlapping sheets containing several thorn-like projections. The crop shows transversal and longitudinal creases and is covered by the same type of overlapping sheets found on the pharynx and the esophagus. The most complex fine structure was observed in the gizzard. This part shows a very irregular epithelium where four different sub units are distinguished, which together conform the characteristic units of this species. The fine structure of the epithelium, of the stomach and gastric caeca is very homogeneous, downy, velvet-like, due to the millions of fine hairs that totally cover this zone of the tract. The intestinal digestive epithelium is very smooth and at the large intestine level it shows some conic prominences.
Virology, 1985
A new type of retrovirus (Sm-MTV) released by cultured cells of a spontaneous mammary tumor from ... more A new type of retrovirus (Sm-MTV) released by cultured cells of a spontaneous mammary tumor from a house musk shrew, Suncus murinus, is described. The Sm-MTV is distinct morphologically from type C particles. In spite of certain morphological similarities to type B and type D retroviruses, the Sm-MTV is readily distinguishable. The extracellular virions had a spikeless envelope containing a centrally located nucleoid with a small electron-dense core surrounded by an inner membrane. The budding particles contained a doughnut-shaped nucleoid. Intracytoplasmic type A particles similar in profile to those associated with mouse mammary tumor cells were also found, and tended to form a small cluster of several particles in the cytoplasm. The virus banded at 1.169 g/cm3 in isopycnic centrifugation and possessed constitutive Mg2+-dependent reverse transcriptase. The viral RNA had a molecular size ranging from 50 to 70 S in its native form and 30 to 40 S in its denatured form by a glycerol gradient ultracentrifugation. Major viral polypeptides were 72K, 69K, 47K, 44K/43K, 27K, 20.5K, and 15K.