Distribution of heavy metals in sediments of Igbede, Ojo and Ojora rivers of Lagos, Nigeria

The distribution of some heavy metals, namely Cd, Pb, Zn, Fe, Cu, Cr and Mn in epipellic sediments of Igbede, Ojo and Ojora rivers of Lagos was studied weekly in the early summer (November) of 2003. The levels of selected trace metals were determined using Atomic Absorption Spectrophotometer (UNICAM 969 AAS SOLAR). Trends in heavy metal burdens in the sediments revealed weekly variations in all the rivers assessed. Statistical analyses also showed different mean levels of trace metals in the aquatic environments, the distribution of which followed the sequence Fe > Zn > Mn > Pb > Cu > Cr > Cd, Fe > Zn > Cu > Mn > Pb > Cr > Cd and Fe > Zn > Mn > Cu > Cr > Pb > Cd in Igbede, Ojo and Ojora rivers respectively. Fe recorded the highest concentration levels (1,582.95 ± 96.57 μg/g–1,910.34 ± 723.19 μg/g) in all the sediments investigated while the Cd levels (0.06 ± 0.10 μg/g–0.47 ± 0.36 μg/g) were the lowest. Expectedly, trace metal concentrations in fine grain muddy sediments of the Igbede and Ojo coastline were much higher than those of Ojora which consist of coarse and sandy deposits covering the near shore area. Generally, the results obtained fell within toler-able limits stipulated by World Health Organization (WHO)

Distribution of heavy metals in sediments of Igbede, Ojo and Ojora rivers of Lagos, Nigeria

Abstract The distribution of some heavy metals, namely Cd, Pb, Zn, Fe, Cu, Cr and Mn in epipellic sediments of Igbede, Ojo and Ojora rivers of Lagos was studied weekly in the early summer (November) of 2003. The levels of selected trace metals were determined using Atomic Absorption Spectrophotometer (UNICAM 969 AAS SOLAR). Trends in heavy metal burdens in the sediments revealed weekly variations in all the rivers assessed. Statistical analyses also showed different mean levels of trace metals in the aquatic environments, the distribution of which followed the sequence Fe > Zn > Mn > Pb > Cu > Cr > Cd, Fe > Zn > Cu > Mn > Pb > Cr > Cd and Fe > Zn > Mn > Cu > Cr > Pb > Cd in Igbede, Ojo and Ojora rivers respectively. Fe recorded the highest concentration levels (1,582.95 ± 96.57 μg/g-1,910.34 ± 723.19 μg/g) in all the sediments investigated while the Cd levels (0.06 ± 0.10 μg/g-0.47 ± 0.36 μg/g) were the lowest. Expectedly, trace metal concentrations in fine grain muddy sediments of the Igbede and Ojo coastline were much higher than those of Ojora which consist of coarse and sandy deposits covering the near shore area. Generally, the results obtained fell within toler

Bulletin of Information 1922-1923

Annual bulletin lists purpose of the school, faculty, register of students, degrees conferred, prizes, curriculum (course of studies), system of instruction, tuition costs and fees, requirements for degree, bar admission, registration statistics, Fourteenth Annual Commencementhttps://ir.lawnet.fordham.edu/bulletins/1016/thumbnail.jp

Design of a silicon cochlea system with biologically faithful response

This paper presents the design and simulation results of a silicon cochlea system that has closely similar behavior as the real cochlea. A cochlea filter-bank based on the improved three-stage filter cascade structure is used to model the frequency decomposition function of the basilar membrane; a filter tuning block is designed to model the adaptive response of the cochlea; besides, an asynchronous event-triggered spike codec is employed as the system interface with bank-end spiking neural networks. As shown in the simulation results, the system has biologically faithful frequency response, impulse response, and active adaptation behavior; also the system outputs multiple band-pass channels of spikes from which the original sound input can be recovered. The proposed silicon cochlea is feasible for analog VLSI implementation so that it not only emulates the way that sounds are preprocessed in human ears but also is able match the compact physical size of a real cochlea

Gender differences in children’s math self-concept in the first years of elementary school

In the course of elementary school children start to develop an academic self-concept reflecting their motivation, thoughts, and feelings about a specific domain. For the domain of mathematics, gender differences can emerge which are characterized by a less pronounced math self-concept for girls. However, studies are rather sparse regarding the early years of elementary school education, hence, the point in time when such gender differences emerge yet remains a matter of debate. In our study, we found that the math self-concept of elementary school children (n = 81) declined from first to second grade. While no differences in math achievement were observed between girls and boys, it became apparent that girls’ math self-concept was already less pronounced than the math self-concept of boys in the first years of elementary school. Our findings emphasize the importance of considering such gender differences even at the beginning of school education

Ambulatory surgery for perianal Crohn’s disease. Study of feasibility

Background. One-third of Crohn’s disease (CD) patients present perianal fistula. The gold standard in the diagnosis and treatment of symptomatic perianal disease (PAD) in CD is the exploration of the anal canal and distal rectum under anesthesia (EUA). This procedure is mainly conducted as a day case surgery. Unfortunately, it is not always possible to proceed within the ideal timing and any delay may well represent a relevant clinical issue. The aim of this study was to evaluate the feasibility of outpatient treatment of symptomatic perianal fistulas in CD patients. Methods. All CD patients under regular follow-up at our inflammatory bowel disease referral center, presenting with symptomatic perianal fistulas, were offered surgical consultation. The data of patients were prospectively collected for three years (February 2014 to February 2017) for the purpose of the study. All clinical information, including previous EUA and/or records from MRI and endoscopic ultrasound, was included. Outpatient anal canal and distal rectum exploration and treatment (OE) were undertaken during the specialist surgical consultation. Fistulas were classified according to Parks’s classification; the type of outpatient treatment and compliance of patients were recorded. Pain was assessed by VAS at the time of the procedure and during the first control. Patients were followed up in the surgical clinic in relation to the study. Results. Ninety-two CD patients with symptomatic perianal fistulas had surgical consultation during the study period. OE was offered to all but 18 patients who fulfilled the exclusion criteria or had an extremely severe disease; six patients refused the OE (8.11%). Of the 68 patients undergoing OE, eleven (16.18%) had previous surgery for perianal disease. The OE was accomplished in sixty-one patients (89.71%), while in 7 patients, it was abandoned for scarce compliance. Nine patients (14.75%) underwent drainage of perianal abscess; in 3 of them, it was possible to probe the fistula tract, find the internal orifice, and pass a loose seton. Overall, setonage was performed in 50 patients (81.97%). Rectovaginal setons were placed in 3 patients and more than one seton (up to 3) in 6 cases. Fistulotomy was performed in 4 simple subcutaneous fistulous tracts. Concordance with the preoperative findings was found in 54 out of 61 patients. EUA was scheduled at the time of OE for the 7 patients who did not complete the procedure. All sixty-one patients who had the OE were followed up for a minimum of 12 months. Conclusions. This preliminary study indicates that OE in CD patients with symptomatic perianal fistulas is safe and feasible in a high-volume referral center. It might provide several benefits, including patients’ logistics, reduce or remove patients’ symptoms and discomfort, allow for a timely start of medical therapy, and avoid further complications

Recognising the ageing face: the role of age in face processing

The effects of age-induced changes on face recognition were investigated as a means of exploring the role of age in the encoding of new facial memories. The ability of participants to recognise each of six previously learnt faces was tested with versions which were either identical to the learnt faces, the same age (but different in pose and expression), or younger or older in age. Participants were able to cope well with facial changes induced by ageing: their performance with older, but not younger, versions was comparable to that with faces which differed only in pose and expression. Since the large majority of different age versions were recognised successfully, it can be concluded that the process of recognition does not require an exact match in age characteristics between the stored representation of a face and the face currently in view. As the age-related changes explored here were those that occur during the period of growth, this in turn implies that the underlying structural physical properties of the face are (in addition to pose and facial expression) invariant to a certain extent