In a survey of over 300 nonevergreen dicots in 69 families, many species were found to have translucent patterns attributed to the presence of bundle-sheath extensions (BSE) on the small and ultimate veinlets. The BSE have been shown by others to inhibit transverse air movement within leaves, and it has been suggested that they are important passageways between vascular tissue and the palisade....

In plants, non-cell autonomous RNA silencing spreads between cells and over long distances. Recent work has revealed insight on the genetic and molecular components essential for cell-to-cell movement of RNA silencing in Arabidopsis. Using a local RNA silencing assay, we report on a distinct mechanism that may govern the short-range (6-10 cell) trafficking of virus-induced RNA silencing from ep...

Neurogenic pulmonary tumours are rare. Neurofibromas are the most common variety and tend to occur in patients with generalized neurofibromatosis, whereas schwannomas arise sporadically in patients who have no evidence of this disorder. A case of solitary benign schwannoma arising in a segmental bronchus is presented, and the published cases reviewed. Microscopically, the tumour had a spindle-s...

The angioarchitecture of microcorrosion casts in 12 hydrocephalic rats and 5 normal control rats was investigated by using scanning electron microscopy to observe the changes of the vascular bed in the cerebral mantle in hydrocephalus. Reduction in the number and caliber of the capillaries in the white matter was the most remarkable change in the hydrocephalic rats. This change increased in pro...

The avian eggshell is a highly ordered calcitic bioceramic composite, with both inorganic and organic constituents. The interactions between the inorganic and organic components within the structure are poorly understood but are likely to occur at the nanometre level. Thus structural variation at this level may impinge on the overall structural integrity and mechanical performance of the eggshe...

Sorghum (Sorghum bicolor (L.) Moench) may be harmlessly intercropped with Urochloa species during the off-season in Brazilian Cerrado. At end of sorghum cycle, forages can used for straw production soybean (Glycine max L.) as summer crop. This study aimed to evaluate cultivated off-season, palisade grass (Urochloa brizantha cv. ‘Marandu’ (Hochst. ex A. Rich). R. D. Webster) and Congo ruziziensi...

New 14C dates from archaeological sites in Oaxaca, Mexico, support R. C. Kelly's observation that intervillage raiding may begin as soon as a region has segmentary societies. The oldest defensive palisade dates to 3260-3160 B.P. in conventional radiocarbon years, only a few centuries after village life was established. Over the next millennium raiding evolved into war, with residences and templ...

Introduction: Gastro-intestinal stromal tumors are mesenchymal tumors they have a unique immunophenotype, expressing c-KIT (CD117), DOG-1 and CD34 in most cases. Most commonly occurring in small intestine and stomach. Case report: We report a case of EUS guided FNA from gastric mass in a 60 year old patient. Cytology showed cellular smears with palisade of tumor cells and blunt end spindle cell...

Dopamine D1 and D2 receptor immunohistochemistry and Golgi techniques were used to study the structure of the adult rat arcuate-median eminence complex, and determine the distribution of the dopamine D1 and D2 receptor immunoreactivities therein, particularly in relation to the tubero-infundibular dopamine neurons. Punctate dopamine D1 and D2 receptor immunoreactivities, likely located on nerve...