4 research outputs found

    An investigation of some biological aspects of three species: tiger toothed croaker, Otolithes ruber, Javelin grunter, Pomadasys kaakan and black pomfret, Parastromateus niger in the Oman Sea for optimizing fishing season

    Get PDF
    During the years 1382-83, some biological aspects of three species Tiger-toothed Croaker, Otolithes ruber, Javelin grunter, Pomadasys kaakan, Black Pomfret, Parastromateus niger, have been investigated in the Oman Sea along Sistan-O-Baluchistan province. Based on the frequency of developed maturity stages (IV, V), a prologed spawning activity extending from August to March was determined for O.ruber, and the Gonadosomatic Index (GSI) suggests two peaks:the minor one in October and the major one in March-April. Comparison of Hepatosomatic Index (HI) and Condition factor (Kn) with the peak spawning indicated a reverse relationship. According to length at first maturity (Lm50%= 40cm) and exploitation of fish at length 42cm above, the stretched optimum mesh size of nets was calculated to be 100mm. On analysis of stomach food item, fish group dominated (80%), which of them Anchovy accounted for 40% of the total frequency. Comparison of mean length between the years 1374-75 and 1382-83 showed 4cm in decrees. Population dynamics parameters were determined through length based modals and the exploitation rate was estimated to be E=0.6, suggesting high level exploitation. The usal streched mesh size of nets(constructed from multifilament webbing) for capturing O.ruber were less than the proposed optimum mesh size of nets, indicating 78% of the total landings were smaller than Lm50%. Total landings in 1381 have increased up to 15% when compared to those of the year 1376. Despite the decrease of total efforts (Panel.day) by 37%, the mean value CPUE has increased up to 82%. Regarding Pomadasys kaakan species, a year-round spawning activity has been observed, with two peaks: A major one in April and an aminor one in September. As those of O.ruber species, there was an inverse relationship between HI and Kn with the peak spawning activity. Based on the length at first maturity (Lm50% = 44cm) and capturing fish of the length at 46cm and above, the stretched optimum mesh size of nets was calculated to be 149.6mm. According to analysis of stomach contents, fish group accounted for 35% of the groups studied, which of them , Largehead hairtail, Trichiurus lepturus linnaeus, constituted 52% of the total frequency. In addition to estimation of population dynamics, the exploitation rate was estimated to be E= 0.49. Majority of the species catch was made by mesh size of nets used for O.ruber of which 133mm mesh size accounted for the level (30%). Information on length distribution showed that 60% of the total fish landed was below Lm50%. Total landings in 1381 decreased to 10% in comparison to 1376.Total fishing efforts and CPUE also decreased to 33% and 24% respectively. For parastromateus Niger, There was a long period spawning activity from March to December, with two peaks: A major one in August and a minor one in March. According to Lm50% (39cm) and catching of fish 39cm above, the stretched optimum mesh size of nets was calculated as 167.7mm. Based on stomach contents, ring-shaped worms and larval shrimp equally made 29% of the total frequency showing the highest contribution. Comparison of mean length indicated 3cm in decrease in 1382-83 when compared to 1374-75. Population dynamics parameters were estimated and the exploitation rate was estimated to be E = 0.54. The usual stretched mesh size of nets for P. niger was 146mm and 81% of the total fish landed were smaller than Lm50%.In 1381,total catch of the species increased four and a half-fold in comparison to 1376, while total efforts decreased up to 28% and CPUE increased two and a half-fold

    Planning road network in mountain forests using GIS and Analytic Hierarchical Process (AHP)

    Get PDF
    Forest road construction is the most costly operation in forestry. Road designing and construction in unsuitable areas may increase construction and maintenance costs and also cause many environmental impacts. Therefore, it is required to pay more attention to forest road design. In this research, we tried to introduce an appropriate method for locating forest roads using GIS and AHP simultaneously. The most important layers in locating forest road include slope, soils type, geology, hydrographic networks, aspects, trees volume m3 per hectare ,tree type and elevation maps which were determined and then by using expert thought and AHP method the study area was classified in five classes including very good, good, medium, bad and worse for forest road construction. Then two new variants were designed on the prepared AHP map: the first variant was designated using traditional method and Pegger extension was applied to design the second. Pegger Planning variant (PP_variant) had the highest efficiency in path from good and bad points of view based on AHP map. The results of this study illustrated that using AHP and GIS simultaneously can introduce an appropriate and suitable method in the forest road network planning

    The First Report of Iranian Registry of Patients with Spinal Muscular Atrophy

    No full text
    BACKGROUND: Insufficient amounts of survival motor neuron protein is leading to one of the most disabling neuromuscular diseases, spinal muscular atrophy (SMA). Before the current study, the detailed characteristics of Iranian patients with SMA had not been determined. OBJECTIVE: To describe the key demographic, clinical, and genetic characteristics of patients with SMA registered in the Iranian Registry of SMA (IRSMA). METHODS: IRSMA has been established since 2018, and the demographic, clinical, and genetic characteristics of patients with SMA were recorded according to the methods of treat neuromuscular disease (TREAT-NMD) project. RESULTS: By October 1, 2022, 781 patients with 5q SMA were registered. Of them, 164 patients died, the majority of them had SMA type 1 and died during the first 20 months of life. The median survival of patients with type 1 SMA was 23 months. The consanguinity rate in 617 alive patients was 52.4%, while merely 24.8% of them had a positive family history. The most common type of SMA in live patients was type 3. Morbidities were defined as having scoliosis (44.1%), wheelchair dependency (36.8%), tube feeding (8.1%), and requiring mechanical ventilation (9.9%). Most of the registered patients had a homozygous deletion of SMN1, while the frequency of patients with higher copy numbers of SMN2, was less in more severe types of the disease. Earlier onset of the disease was significantly seen in patients with lower copy numbers of SMN2. The neuronal apoptosis inhibitory protein (NAIP) gene deletion was associated with a higher incidence of more severe types of SMA, higher dependency on ventilators, tube feeding, and earlier onset of the disease. CONCLUSIONS: The IRSMA is the first established Iranian nationwide registry of patients with SMA. Using this registry, decision-makers, researchers, and practitioners can precisely understand the epidemiology, characteristics, and genetics of patients with SMA in Iran
    corecore