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Factors influencing development of management strategies for the Abou Ali River in Lebanon. I: Spatial variation and land use
Surface water bodies are progressively subject to increasing stress as a result of environmentally degrading processes primarily related to anthropogenic activities. This study assesses and examines the impact of land use and anthropogenic activities on the spatial variation in water quality of the Abou Ali River in North Lebanon. It is the first detailed study of its kind in Lebanon and adds to the existing Knowledge by shedding light on a relatively small Mediterranean river in a developing country where there is a paucity of such studies. The assessment was conducted at the end of the dry season in 2002 and 2003 and the end of the wet season in 2003 and 2004. The study has demonstrated the importance of anthropogenic influences on the water quality of the Abou Ali River Basin, as concentrations of most contaminants were higher at locations with greatest human activity. The most adversely affected area was the section of the river that flows through an entirely urbanized and highly populated region, the Tripoli conurbation. Upstream rural sites were enriched by contaminants primarily from non-point sources such as agricultural runoff and poultry litter whereas contaminant concentrations at the urban sites were enriched by a combination of sewage discharge and flow of contaminants from upstream. If the Abou Ali River is to be utilized as a managed water resource and its water quality sustained, point source discharges will require treatment and land use management must be planned to minimize the impact of diffuse source pollution on the river. A high priority should be given to the implementation and enforcement of the precautionary and polluter pays principles. Moreover, an effective legal, economic and institutional framework is required to encourage investment in waste reduction and control and to introduce environmentally sound practices
Geometrical Properties of Coupled Oscillators at Synchronization
We study the synchronization of nearest neighbors coupled oscillators in
a ring. We derive an analytic form for the phase difference among neighboring
oscillators which shows the dependency on the periodic boundary conditions. At
synchronization, we find two distinct quantities which characterize four of the
oscillators, two pairs of nearest neighbors, which are at the border of the
clusters before total synchronization occurs. These oscillators are responsible
for the saddle node bifurcation, of which only two of them have a phase-lock of
phase difference equals /2. Using these properties we build a
technique based on geometric properties and numerical observations to arrive to
an exact analytic expression for the coupling strength at full synchronization
and determine the two oscillators that have a phase-lock condition of
/2.Comment: accepted for publication in "Communications in Nonlinear Science and
Numerical Simulations
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Rethinking reactive halogen budgets in the midlatitude lower stratosphere
Current stratospheric models have difficulties in fully explaining the observed midlatitude ozone depletion in the lowermost stratosphere, particularly near the tropopause. Such models assume that only long-lived source gases provide significant contributions to the stratospheric halogen budget, while all the short-lived compounds are removed in the troposphere, the products being rained out. Here we show this assumption to be flawed. Using bromine species as an example, we show that in the lowermost stratosphere, where the observed midlatitude ozone trend maximizes, bromoform (CHBr3) alone likely contributes more inorganic bromine than all the conventional long-lived sources (halons and methyl bromide) combined. Copyright 1999 by the American Geophysical Union
Transverse testicular ectopia with persistent Mullerian duct syndrome
The aim of the study was to report on three patients who had transverse testicular ectopia (TTE) with persistent Mullerian duct syndrome (PMDS). Three cases of transverse testicular ectopia and persistent Mullerian duct syndrome were managed at our institution between 2000 and 2009. They presented with right-sided inguinal hernia and left nonpalpable testes. The diagnosis was established during diagnostic laparoscopy. The Mullerian structure was divided in the midline laparoscopically in two patients and by open technique in the third. Good length could be obtained to bring the crossed ectopic testis into the ipsilateral scrotal sac in all cases. Awareness of this anomaly and understanding of the embryological process of testicular descent and its associated aberration are prerequisites for the proper management of this rare anomaly. These findings highlight the importance of diagnostic laparoscopy in all patients presented with nonpalpable testes.Keywords: crossed testicular ectopia, persistent Mullerian duct syndrome, transverse testicular ectopi
Editorial: Mesoblastic nephroma: Pathological features
This correspondence is an editorial comment on the previously published article entitled “Trois observations de néphrome mésoblastique avant l’âge de 6 mois” in AFJU Vol. 20, No. 3 Pages 161–164”. Since the authors of that article focused mainly on the clinical and radiological aspects of the tumor with only very brief reference to its pathological features, and since the variable behavior of mesoblastic nephroma is determined mainly by its histologic type, we found it worthwhile to elaborate more on the gross and microscopic features of that tumo
Absent testis: does it exist in 46,XY males?
Aim To challenge the concept of genetically absent testis in normal 46,XY males.Background The term absent testes has been used in the literature to denote vanishing testis, atrophied testis, nubbin of testicular tissue, or genetically absent testes. When no testicular tissues are found during diagnostic laparoscopy, the vas and testicular vessels are traced as leading pointsfor testicular localization, and if both endblindly at a closed ring, vanishing testis is diagnosed. When the vas and vessels are seen entering the canal, a testicular nubbin may be present at the end of the epididymis.Methods Both Mullerian inhibitory factor and testosterone act locally as paracrine hormones. Unilateral absent testis should be associated with an ipsilateral persistent of Mullerian tissues. Individuals with bilateral testicular agenesis will develop into a phenotypic female with persistent Mullerian structures.Results The absence of Mullerian structures in patients with impalpable testis means that there has been a functional testis that survived well beyond the ninth week of gestation. We have encountered testicles at the subrenal position after an initial laparoscopic finding of an absent.Conclusion Based on embryological process of testicular development and testicular descent, agentic absent testis cannot exist. Therefore we strongly recommend to re-scope all patients who were initially diagnosed as absent testis to look for a hidden testis at the initial site of development and along the line of descent. Keywords: absent testis, undescended testis, vanishing testi
The 2011 Thailand flood: climate causes and return periods
Thailand is one of the wealthiest and most
developed countries in southeast Asia.
However, its tropical location and the influence
of seasonal monsoon rains and local
topography make it prone to floods. The
floods in 2011 were especially severe, causing
estimated losses of US 12 billion
(insured; Swiss Re, 2012). The insured loss
ranks easily as the highest-ever worldwide
from a freshwater flood disaster (Swiss Re,
2012). The primary reason for the floods was
record rainfall: over Thailand as a whole,
annual rainfall in 2011 was the highest in the
country’s 61-year precipitation record (Thai
Meteoro logical Department, 2011). In this
article we first review the nature, impacts and
historical ranking of the 2011 Thailand floods.
We then examine the 2011 rainfall totals and
anomalies across Thailand and use these
with other data to discuss the climate causes
for the exceptional rainfall. We then estimate
the rainfall return period for this flooding
event and compare this with satellite-derived
return periods for the 2011 river flow. Finally,
we bring together the different estimated
return periods to provide a firmer assessment
of how likely it is that a flood of the
magnitude of 2011 will happen again
Assessment of anticlastogenic activity of cinnamic acid: Anticlastogenic index (ACI) and model simulation
Cinnamic acid and its derivatives are an important member of the phenolic compound used in food supplements. They usually occur in various conjugated forms, more frequently esters and glycosides. Mice (Mus musculus, 2n = 40) were employed as an experimental mammalian system to assess the anticlastogenic activity of cinnamic acid (CA) induced by Endoxan. Four doses; 1/32, 1/16, 1/8 and 1/4 of the LD50 of CA (5, 10, 20 and 40 mg/kg, respectively) in combination with five administration times of CA were tested. Micronucleated polychromatic erythrocytes (PCE) and mitotic index (MI) were used as a sensitive short term genotoxic bioassays. The results obtained showed that low doses (1/32 LD50 and 1/16 LD50) decreased the percentage of PCE significantly compared with that of the positive control and closer to that of the negative control. The data of this study were used to calculate a new index called anticlastogenic index (ACI). The new index measures the anticlastogenic activity of a compound or an extract. The ACI beside the percentage of PCE can give a deeper look of the anticlastogenic activity of compounds. It also makes it easy to draw conclusions from the genotoxicity data. The maximum ACI of CA was achieved when both CA and Endoxan were given concurrently. On the other hand, the higher doses of CA (1/8 and 1/4 LD50) caused a significant increase in the percentage of PCE. This gives evidence that CA at high doses (20 and 40 mg/kg) would be considered as a positive clastogen itself. CA significantly decreased the mitotic index compared with the negative control. In addition, high doses showed sharp decrease in mitotic index. Direct significant correlation coefficient was found between the ACI and the mitotic index. The data also were used for the simulation of a model to predict the ACI of doses with different relative timing to a treatment of the clastogen that were not conducted experimentally in the limit of experiment data range.Key words: Anticlastogenic, cinnamic acid, anticlastogenic index, ACI, mitotic index, mice, model simulation of ACI
BSDEs with stochastic Lipschitz condition and quadratic PDEs in Hilbert spaces
This paper is devoted to the study of the differentiability of solutions to
real-valued backward stochastic differential equations (BSDEs for short) with
quadratic generators driven by a cylindrical Wiener process. The main novelty
of this problem consists in the fact that the gradient equation of a quadratic
BSDE has generators which satisfy stochastic Lipschitz conditions involving BMO
martingales. We show some applications to the nonlinear Kolmogorov equations
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