local people, who benefit from this form of tourism economically, and often more than mass tourism.Ecosystem protection can occur as ecotourism can help the funding of the operation of protected areas (i.e. national parks) Protected areas such as national parks often need to employ (and pay for) park rangers, and if Safari lodges are foreseen, staff is needed for this as well. For many countries, ecotourism is not simply a marginal activity to finance protection of the environment, but a major industry of the national economy. For example, in Costa Rica, Ecuador, Nepal, Kenya, Madagascar and territories such as Antarctica, ecotourism represents a significant portion of the gross domestic product and economic activity. In Tan-awan, Oslob, Philippines, the ecotourism of swimming with whale sharks makes up to US$5 million a year, which is used to help stop overfishing and damage to the natural ecosystem. In Antarctica 2002, a study on ecotourism benefits was conducted by joint tourism research units from the US and Australia to assess ecotourisms immediate influence of Antarctica cruise participation on tourists’ knowledge, attitudes, and behaviors. They were also investigating the longer-term influence of Antarctica cruise participation on tourists’ knowledge, attitudes, and behaviors. Immediately after participation, scores on the general environmental behavior and associated intentions index increased 10% with respondents intending to increase significantly. However, three months after their tour, the retrospective respondents showed no significant increases in behaviors compared to the pre-visitation group. Terminology and history
Ecotourism is a late 20th-century neologism compounded from eco- and tourism.
The straight angle between the ovarian vein (or testicular vein in males in the case of varicocoele) and the renal vein has been proposed as a cause of decreased blood return.A related diagnosis is "Nutcraker Syndrome" where the left renal vein is described as being compressed between the aorta and the superior mesenteric artery. This is reported to cause collateral flow paths to open up to drain the left kidney i.e. reversed flow (reflux caudally) in the left renal vein. Pelvic Congestion Syndrome, vaginal and vulval varices, lower limb varices are clinical sequelae. Virtually all such patient are female and have been pregnant, often multiply. The ovarian vein often displays incompetent valves. This has been observed more often in women with a higher number of previous pregnancies. Pressure from the baby might hinder the return of blood through the ovarian vein. It has to be noted however that dilation of the urinary tract is a normal observation in pregnancy, due to mechanical compression and the hormonal action of progesterone. Ovarian vein dilatation might also follow venous thrombosis (clotting inside the vein). Another proposed mechanism of obstruction is when the ovarian vein and ureter both run through a sheath of fibrous tissue, following a local inflammation. This could be seen as a localised form of retroperitoneal fibrosis.Following obstruction, the ureter displays an abnormal peristalsis (contractions) towards the kidney instead of towards the bladder. This is thought to cause the colicky pain (similar to renal colic), and it is relieved after surgical decompression.