The floral nectaries are associated with the androecium.Vivipary, the germination of seeds before they are shed from the parent plant, is a rare event in angiosperms involving complex ecophysiological processes. In the centre of the ovary a primordium arises that develops into the single basal circinotropous bitegmic ovule. Continuity between the gynoecial primordia is reached earlier in the Plumbagoideae than in the Armerioideae. These primordia soon reach continuity and develop into the superior unilocular gynoecium. After inception of the common primordia, five gynoecial primordia alternating with the common primordia are initiated simultaneously on the corners of the apex that has become pentagonal. Soon, two distinct growth-centres can be observed on each of these primordia: a petal primordium at the abaxial side and a stamen primordium on the top. Meanwhile, five common stamen-petal primordia that alternate with the sepal primordia are initiated simultaneously on the flattened apex. These soon reach continuity and develop into the synsepalous calyx. The five sepal primordia are initiated simultaneously or spirally. The early ontogenetic stages in all species examined are sufficiently similar to propose the following familial description. The ovules are circinotropous, bitegmic, crassinucelate, and have long funiculus as in many other Cactaceae.Ī scanning electron microscopic study of the floral ontogeny of seven species of the Plumbaginaceae (representing five genera of the Armerioideae and two of the Plumbagoideae) is presented. The stigma has 9-10 lobes with a secretory epidermis. The nectariferous region occurs on the inner surface of the hypanthium. The ovary has inverted vascular bundles in a similar pattern as in Pereskia. The gynoecium is syncarpous with 9-10 carpels, pluriovulate, and with parietal placentation. The wall of the young anther is formed by epidermis, endothecium, a middle layer, and binucleate secretory tapetum that eventually becomes uninucleate. The androecium has many stamens with tetrasporangiate and bithecal anthers. Secretory cavities containing mucilage and calcium oxalate crystals occur throughout the fl oral parenchymatous tissue. All fl ower whorls have uniseriate epidermis. The fl ower is sessile and epigynous with a well-developed hypanthium. Flowers and fl ower buds were collected in Maringá, Paraná State, Brazil, fi xed, processed, and analyzed under light microscope and scanning electron microscope. The aim of this contribution was to analyze the morpho-anatomical fl oral structure of Epiphyllum phyllanthus (L.) Haw., a widely distributed species across South America, occurring in humid forests as an epiphyte.
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With more than 215,000 students at 217 schools having experienced gun violence at school since Columbine in 1999, as reported by ABC News, active shooter preparedness has become a more evolved and elaborate part of training in schools as well as outside of them.Įarlier this year, the Department of Homeland Security developed a software to train teachers in an active shooter situations using a realistic computer simulation that depicts the chaos of an actual shooting, The New York Times wrote. “It’s just not what we were trained to do 30 years ago,” McCarthy said. Kevin McCarthy, of the Nassau County Bureau of Special Operations, told the audience that when he began his police training three decades ago, he never would have believed he would be training officers about what to do in a school shooting. “I’m glad that Nassau County is doing something to better protect their schools, but at the same time tragedies like this just shouldn’t be happening.” “School shootings are an epidemic in this country, and it’s horrifying seeing that these elementary and middle schools now have to incorporate mass shooting procedures essentially into their curriculum,” said Gabrielle Spann, a senior community health major at Hofstra who attended the forum. “We are collaborating to be as quick and responsive as possible in any emergency involving a school,” Curran said in the announcement. In March, Nassau County Executive Laura Curran and Ryder debuted the school resource program at the Nassau Police Academy in Massapequa Park. Ryder said the police department’s goal for the RAVE System is to take time away from an attacker by responding to instantly, as shooting incidents typically last only eight to 10 minutes. The program includes protocols such as frequent patrol visits by Nassau County police officers, routine local lockdown drills and the use of the RAVE Panic Button System – a rapid alert system designed to directly connect school administration to law enforcement and emergency dispatchers in the likelihood of a life-threatening event. |
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January 2023
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