Simulating long-term effect of Hyrcanian forest loss on phosphorus loading at the sub-watershed level     

Fatemeh RAJAEI  Abbas E SARI  Abdolrassoul SALMANMAHINY  Timothy O RANDHIR  Majid DELAVAR  Reza D BEHROOZ  Alireza M BAVANI 《干旱区科学》2018,10(3):457-469

Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus(P) nutrient, thus impacting the water quality. Modeling the effect of forest loss on surface water quality provides valuable information for forest management. This study predicts the future impacts of forest loss between 2010 and 2040 on P loading in the Tajan River watershed at the sub-watershed level. To understand drivers of the land cover, we used Land Change Modeler(LCM) combining with the Soil Water Assessment Tool(SWAT) model to simulate the impacts of land use change on P loading. We characterized priority management areas for locating comprehensive and cost-effective management practices at the sub-watershed level. Results show that agricultural expansion has led to an intense deforestation. During the future period 2010–2040, forest area is expected to decrease by 34,739 hm~2. And the areas of pasture and agriculture are expected to increase by 7668 and 27,071 hm~2, respectively. In most sub-watersheds, P pollution will be intensified with the increase in deforestation by the year 2040. And the P concentration is expected to increase from 0.08 to 2.30 mg/L in all of sub-watersheds by the year 2040. It should be noted that the phosphorous concentration exceeds the American Public Health Association′s water quality standard of 0.2 mg/L for P in drinking water in both current and future scenarios in the Tajan River watershed. Only 30% of sub-watersheds will comply with the water quality standards by the year 2040. The finding of the present study highlights the importance of conserving forest area to maintain a stable water quality.  相似文献   

Epididymis Ligation: A Minimally Invasive Technique for Preparation of Teaser Rams     

AMIN TAMADON  DVM    BEHROOZ NIKAHVAL  DVM DVSc    MASOOD SEPEHRIMANESH  DVM    MARYAM MANSOURIAN  DVM PhD    ABOUTORAB TABATABAEI NAEINI  DVM DVSc    SAEED NAZIFI  DVM  PhD 《Veterinary surgery : VS》2010,39(1):121-127

Objective— To describe a minimally invasive technique for preparation of teaser rams by needle-assisted ligation through the tail of the epididymis.
Study Design— Experimental study.
Animals— Mature rams (n=6), estrus-induced ewes (2).
Methods— After local anesthesia, epididymis ligation was achieved by restraining the testis distally within the scrotal sac and passing suture through a hypodermic needle inserted between tail of epididymis and distal pole of testis, caudomedial to craniolateral through the scrotum. The needle was removed leaving the suture in place and the testis pushed up dorsally, then the needle was reinserted through the original holes and the suture passed back through the needle, which was withdrawn. This resulted in the suture forming a complete loop around the epididymis. The suture ends were tied ligating the epididymis. Semen was evaluated pre- and postligation. Testes were removed after 30 days for gross and histologic examination.
Results— Epididymis ligation was accomplished without postoperative complications. Three weeks after the epididymis ligation, no motile and live spermatozoa were found in ejaculates. From 5 to 28 days after epididymis ligation, attraction to ewes and libido was unchanged and similar to 14 days before ligation.
Conclusions— This novel minimally invasive technique is a simple, alternative method for preparation of teaser rams.
Clinical Relevance— This method is simply performed, without skin wounds, and minimal postoperative care is needed. The technique should be readily adaptable to other species.  相似文献