Field Testing the Riparian Ecosystem Management Model on a Riparian Buffer in the North Carolina Upper Coastal Plain

The riparian ecosystem management model (REMM) was field tested using five years (2005‐2009) of measured hydrologic and water quality data on a riparian buffer located in the Tar‐Pamlico River Basin, North Carolina. The buffer site received NO₃‐N loading from an agricultural field that was fertilized with inorganic fertilizer. Field results showed the buffer reduced groundwater NO₃‐N concentration moving to the stream over a five‐year period. REMM was calibrated hydrologically using daily field‐measured water table depths (WTDs), and with monthly NO₃‐N concentrations in groundwater wells. Results showed simulated WTDs and NO₃‐N concentrations in good agreement with measured values. The mean absolute error and Willmott's index of agreement for WTDs varied from 13‐45 cm and 0.72‐0.92, respectively, while the root mean square error and Willmott's index of agreement for NO₃‐N concentrations ranged from 1.04‐5.92 mg/l and 0.1‐0.86, respectively, over the five‐year period. REMM predicted plant nitrogen (N) uptake and denitrification were within ranges reported in other riparian buffer field studies. The calibrated and validated REMM was used to simulate 33 years of buffer performance at the site. Results showed that on average the buffer reduced NO₃‐N concentrations from 12 mg/l at the field edge to 0.7 mg/l at the stream edge over the simulation period, while the total N and NO₃‐N load reductions from the field edge to the stream were 77 and 82%, respectively.     

A Classification System for Characterization of Physical and Non-Physical Work Factors

A comprehensive evaluation of work-related perfomance factors is a prerequisite to developing integrated and long-term solutions to workplace performance improvement. This paper describes a work-factor classification system that categorizes the entire domain of workplace factors impacting performance. A questionnaire-based instrument was developed to implement this classification system in industry. Fifty jobs were evaluated in 4 different service and manufacturing companies using the proposed questionnaire-based instrument. The reliability coefficients obtained from the analyzed jobs were considered good (.589 to .862). In general, the physical work factors resulted in higher reliability coefficients (.847 to .862) than non-physical work factors (.589 to .768). performance work-factor system classification     

Studies on the maturation-accelerating pheromone of the desert locustSchistocerca gregaria (Orthoptera: Acrididae)

Summary The accelerating effect of mature males of the desert locust,Schistocerca gregaria, on the maturation of immature male and female conspecifics was confirmed. The onset of sexual activity was found to correlate with yellowing of the male insects. Using the colour as an indicator of maturation, the maturation-hastening effect of an hexane extract from mature males was also confirmed. Likewise, volatiles from mature males placed in the upper storey of a two-chamber bioassay system (no visual or tactile contact possible) and charcoal-trapped volatiles from the mature males also induced accelerated maturation in recipient males placed in the lower storey. GC and GC-MS analysis of volatiles collected from 4-week-old mature males showed the presence of anisole, benzaldehyde, veratrole, phenylacetonitrile and 4-vinylveratrole, roughly at the ratio 4.8:7.0:3.3:79.8:5.0. In addition, guaiacol, phenol, benzoylnitrile, benzyl alcohol and 2-benzoyloxyphenylacetonitrile were present in smaller amounts. These compounds were either absent or found only in trace amounts in the female volatiles. Earlier, we had shown that essentially the same blend collected from younger males (10–20 d old, not yet demonstrating signs of maturation) induced strong aggregation of both sexes of adult desert locusts, suggesting a parsimonious role for the pheromone system: as an adult aggregation signal and as a maturation accelerant in young adults.     

A Comparative Study On the Levels of Trace Metals in Some Mediterranean and Red Sea Fishes

Samples of Mugil cephalus, Liza ramada, Siganus luridus, Siganus rivulatus, Epinephelus alexandrinus, Epinephelus areolatus, Epinephelus fasciatus, Epinephelus chlorostigma, Cephalopholis argus and Cephalopholis sonnerati were collected from the Mediterranean and Red Seas and their muscle and bone analyzed by AAS for some trace metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb). the results showed that these metals accumulate in the bones to a greater extent than in the muscle. the highest accumulated element is cobalt (4.7-20.8 times), while the lowest is lead (1.1-2.5 times). the accumulation is more pronounced in Red Sea species than in Mediterranean species. the elevated levels of lead in Mugil cephalus (2.6-3.0 mg kg^-1) and Epinephelus alexandrinus (3.0-3.9 mg kg^-1) were attributed to the intake in food in the polluted environment of Alexandria coastal water. the relationship between body size and concentration of trace metals using a standard linear regression technique gives a significant positive correlation for cobalt, manganese, iron and lead in the muscle, as well as for lead in the bones of Mugil species from the Red Sea, while the Mediterranean species showed little correlation.

There is a tendency for increased concentrations of the essential metals manganese, iron and copper with increasing trophic level of the fish, while the opposite is true for the toxic metals chromium and lead. Our results indicate that there is no risk from toxic metal concentrations in muscle of fish from the Mediterranean and Red Seas consumed by man even in contaminated areas.     

Effect of grazing on plant attributes and hydrological properties in the sloping lands of the East African highlands

Extending livestock grazing to the steep slopes has led to unstable grazing systems in the East African Highlands, and new solutions and approaches are needed to ameliorate the current situation. This work was aimed at studying the effect of livestock grazing on plant attributes and hydrological properties. The study was conducted from 1996 to 2000 at the International Livestock Research Institute at Debre Ziet Research Station. Two sites were selected: one at 0–4% slope, and the other at 4–8% slope. The treatments were: (1) no grazing (control); (2) light grazing, 0.6 animal unit months per hectare (aum/ha); (3) moderate grazing, 1.8 aum/ha; (4) heavy grazing, 3.0 aum/ha; (5) very heavy grazing, 4.2 aum/ha; (6) initially plowed and continuously very heavily grazed, 4.2 aum/ha. The result showed that species richness, infiltration rate, bare ground, and soil loss significantly varied with grazing pressure. Species richness was higher in grazed plots compared to nongrazed plots. Biomass yield improved on heavily grazed plots as cow dung accumulated over years. Cynodon dactylon plant species persisted with livestock grazing pressure in both sites. Infiltration rate improved and soil erosion declined in all treatments after the first year.     

Effect on water resources from upstream water diversion in the Ganges basin

Bangladesh faces at least 30 upstream water diversion constructions of which Farakka Barrage is the major one. The effects of Farakka Barrage on water resources, socioeconomy, and culture have been investigated downstream in the basins of the Ganges and its distributaries. A diversion of up to 60% of the Ganges water over 25 yr has caused (i) reduction of water in surface water resources, (ii) increased dependence on ground water, (iii) destruction of the breeding and raising grounds for 109 species of Gangetic fishes and other aquatic species and amphibians, (iv) increased malnutrition, (v) deficiency in soil organic matter content, (vi) change in the agricultural practices, (vii) eradication of inland navigable routes, (viii) outbreak of waterborne diseases, (ix) loss of professions, and (x) obstruction to religious observances and pastimes. Further, arsenopyrites buried in the prebarrage water table have come in contact with air and formed water-soluble compounds of arsenic. Inadequate recharging of ground water hinders the natural cleansing of arsenic, and threatens about 75,000,000 lives who are likely to use water contaminated with up to 2 mg/L of arsenic. Furthermore, the depletion of surface water resources has caused environmental heating and cooling effects. Apart from these effects, sudden releases of water by the barrage during the flood season cause devestating floods. In consideration of such a heavy toll for the areas downstream, strict international rules have to be laid down to preserve the riparian ecosystems.     

Treatment of oily refinery wastes using a dissolved air flotation process

Refinery wastewater from Moustorod oil refinery, Cairo, Egypt, was treated by chemical coagulation. This step was followed by rapid solid-liquid separation using flotation under pressure of 4 atm. A flotation tank was designed for this purpose. Gas liquid chromatography was used for determination and identification of hydrocarbon compounds in refinery wastewater. The treatment technique proved to be very promising for reducing the hydrocarbon compounds, as well as other pollutants, to a very low concentration. The results obtained showed that some of the hydrocarbon compounds were completely removed.     

Multiple regression analysis of the sources of variation in orientation of two sympatric sandhoppers, <Emphasis Type="Italic">Talitrus saltator</Emphasis> and <Emphasis Type="Italic">Talorchestia brito</Emphasis>, from an exposed Mediterranean beach

Two sympatric species from an exposed sandy beach in north-western Tunisia, the sandhoppers Talitrus saltator (Montagu) and Talorchestia brito Stebbing, were compared as regards orientation under natural conditions. Sets of experiments were carried out on the beach using two experimental arenas, one permitting the view of both the sky and landscape and the other of the sky only. Replicates were made at different hours of the day, in different days and period of the year and with various climatic conditions. Multiple regression models were fitted to the angular data obtained. These models allow an estimate of the trends of variation depending on a combination of factors. The simultaneous effects of environmental factors influencing orientation were quantified for each species. The sun was confirmed as the major orientation cue in these populations, but the concentration of directional choices was enhanced by the landscape vision. The climatic factors affected orientation in different ways depending on the time of day and year. When the two species were compared, Talitrus saltator showed a higher flexibility of response than Talorchestia brito under the same environmental conditions, supporting the hypothesis of a higher level of terrestrialization of the former species.     

Fetal hypothyroidism as a complication of amiodarone treatment for persistent fetal supraventricular tachycardia

We present a case of persistent fetal supraventricular tachycardia where transplacental and direct fetal treatment with amiodarone caused an iatrogenic hypothyroidism. This condition was successfully managed with the intra-amniotic instillation of 250 μg of L-thyroxine weekly, for 3 weeks. A male infant was delivered at 32 weeks by Caesarean section. The neonatal electrocardiogram showed Wolf-Parkinson-White (WPW) syndrome, which was controlled by digoxin alone. Thyroid function normalized quickly and the baby is developing normally.     

Ozone and other air quality-related variables affecting visibility in the southeast United States

An analysis of ozone (O3) concentrations and several other air quality-related variables was performed to elucidate their relationship with visibility at five urban and semi-urban locations in the southeast United States during the summer seasons of 1980-1996. The role and impact of O3 on aerosols was investigated to ascertain a relationship with visibility. Regional trend analysis over the 1980s reveals an increase in maximum O3 concentration coupled with a decrease in visibility. However, a similar analysis for the 1990s shows a leveling-off of both O3 and visibility; in both cases, the results were not statistically significant at the 5% level. A case study of site-specific trends at Nashville, TN, followed similar trends. To better understand the relationships between O3 concentration and visibility, the analysis was varied from yearly through daily to hourly averaged values. This increased temporal resolution showed a statistically significant inverse relationship between visibility and O3. Site-specific hourly r2 values ranged from 0.02 to 0.43. Additionally, by performing back-trajectory analysis, it was found that the visibility degraded by air mass migration over polluted areas.