Neobična pristunost juvenilnih primjeraka vrste Synagrops japonicus u jugozapadnom Mediteranu

This paper reports additional records of the Indo-Pacific fish Synagrops japonicus (Doderlein, 1884) in Western Mediterranean. Twenty juveniles of this species ranging from 4 to 4.8 cm (TL) were caught in Annaba Bay, Algeria, using beach seine, in Summer of 2011 (9 specimens, 4 ≤ TL ≤ 4.6 cm) and 2012 (11 specimens, 4.2 ≤ TL ≤ 4.8 cm). Some hypotheses on the origin of this unusual presence are discussed.U ovom radu se navode dodatni nalazi vrste Synagrops japonicus (Doderlein, 1884) u zapadnom Mediteranu. Uhvaćeno je dvadeset juvenilnih primjeraka ove vrste u rasponu od 4 do 4,8 cm (TL) u Annaba zaljevu, Alžir, pomoću obalne mreže potegače, u ljeto 2011. godine (9 primjeraka, 4 ≤ TL ≤ 4,6 cm) i 2012. (11 primjeraka, 4.2 ≤ TL ≤ 4,8 cm). U radu su iznesene neke hipoteze o podrijetlu ove neobične prisutnosti

Ecological and biological characterisrics of Artemia salina (Crustacea, Anostraca) in the sebkha Ez-Zemoul, northeastern Algeria

This study concerned some biological and ecological aspects of Artemia salina (Branchiopoda, Anostraca) from the sebkha Ez-Zemoul, situated in northeastern Algeria (35° 53’ N - 06° 30’ E). The survey of the demographic structure and density of Artemia population between January 2003 and February 2005 shows that this brine shrimp appeared in November after the cyst hatching, reached a maximum density in March (56 ind/L in 2003 and 38 ind/L in 2004) and disappeared completely in July. The sex ratio was always in favour of males. Its values were very high (1.77 - 31.80). Males were smaller than females. Their respective lengths varied, according to the sampling period, between 7.1 mm and 8.8 mm and between 8.7 mm and 10.4 mm. The length of females at first sexual maturity varied between 7 mm (November) and 9 mm (April). Oviparity was the main mode of reproduction (90 - 100 %). Females were relatively fertile with an average brood size comprised between 19.50 (May 2003) and 104.7 (March 2003) offsprings/femaleCette étude est consacrée à quelques aspects de l'écologie et de la biologie d'Artemia salina (Branchiopode, Anostracé) de la sebkha Ez-Zemoul, située dans le nord-est de l'Algérie (35°53' N - 06°30' E). Le suivi de sa structure démographique et de sa densité, entre janvier 2003 et février 2005, montre que ce crustacé apparaît en novembre, suite à l'éclosion des cystes, atteint une densité maximale en mars (56 ind/L en 2003 et 38 ind/L en 2004) et disparaît complètement à partir de juillet. La sex-ratio est toujours en faveur des mâles et ses valeurs sont très élevées (1,77 - 31,80). Ces derniers sont plus petits que les femelles. Les tailles moyennes des deux sexes varient, selon la période d'échantillonnage, entre 7,1 mm et 8,8 mm et entre 8,7 mm et 10,4 mm respectivement. La taille à la première maturité sexuelle des femelles varie entre 7 mm (novembre) et 9 mm (avril). L'oviparité est le principal mode de reproduction (90 - 100 %). La fécondité varie entre 19,5 (mai 2003) et 104,7 zygotes/portée (mars 2003)

DIET COMPOSITION AND TROPHIC LEVEL OF GREATER FORKBEARD Phycis blennoides (GADIFORM: PHYCIDAE) FROM THE ALGERIAN COAST

U razdoblju od prosinca 2013. do lipnja 2015. istraživan je sastav ishrane tabinje bjelice Phycis blennoides (Brünnich, 1768) na obali Alžira pružajući informaciju o ekologiji vrste te pridonoseći boljem razumijevanju strategije njenog hranjenja. Analizirano je ukupno 956 primjeraka čija je totalna dužina (TL) varirala između 9,7 i 54,5 cm i mase (W) između 2,80 i 1334,11 g. Za obilježavanje relativne važnosti različitih taksona u progutanoj hrani, korišten je indeks relativne važnosti (%IRI) kombinirajući tri glavna deskriptora prisustva različitog progutanog plijena. Kvalitativne i kvantitativne varijacije u ishrani proučavane su prema spolu, veličini i godišnjim dobima. Prosječni godišnji indeks praznine crijeva (% V) je bio 5,51. Nije varirao između sezona (χ²cal = 5,43, χ²th = 7,82, α = 5%) i veličine (χ²cal = 2.08, χ²th = 5,99, α = 5%), ali je bio različit između mužjaka (%V = 4,94) i ženki (%V= 12,78). Kvalitativna analiza sadržaja želudca otkriva prilično raznolik raspon predacije s izbrojana 1342 plijena ukupne mase 462,84 g što odgovara prosječnom broju (AN) i masi (AW) od 3,03 odnosno 1,04 g. Ova vrsta se hrani bentoskim plijenom, uglavnom sastavljenim od rakova plivača (natantia) (% IRI = 44,84) i riba košunjača (% IRI = 2,61) te s intraspecifičnim plijenom (% IRI = 6,15). Ova pojava kanibalizma je česta kod primjeraka s TL koja premašuje 20 cm a još je češća kod ženki u zimskom periodu. Značajne razlike u prehrambenim navikama P. blennoides javljaju se prema spolu, veličini ribe i godišnjim dobima. Trofička razina (TROPH) bila je visoka (3.66 <TROPH <3.97), što odgovara karnivornom karakteru vrste.The diet of the greater forkbeard Phycis blennoides (Brünnich, 1768) of the Algerian coast was studied between December 2013 and June 2015, providing information on its ecology for a better understanding of the feeding strategy. A total of 956 individuals, whose total length (TL) varied between 9.7 and 54.5 cm and weight (W) between 2.80 and 1334.11 g, were examined. The index of relative importance (%IRI), combining the three main descriptors of the presence of different ingested prey (%F, %N, %W), was used to characterize the relative importance of different food taxa. Qualitative and quantitative variations in diet were studied according to sex, size and seasons. The average annual digestive vacuity index (%V) was 5.51. It did not vary between seasons (χ²cal = 5.43, χ²th = 7.82, α = 5%) and size (χ²cal = 2.08, χ²th = 5.99, α = 5%), but was different between male (%V = 4.94) and female (%V= 12.78). Qualitative analysis of stomach contents reveals a fairly diverse range of predation with 1342 preys counted for a total weight of 462.84 g, which corresponds to an average number (AN) and weight (AW) of 3.03 and 1.04 g, respectively. This species feeds on benthic preys, composed mainly of natantia crustaceans (%IRI = 44.84) and teleost fish (%IRI = 2.61) with intraspecific preys (%IRI = 6.15). This cannibalism was frequent in specimens with a TL that exceeds 20 cm; it was even more frequent in females as well as in winter. Significant differences in feeding habits of P. blennoides occurred according to sex, fish size and between seasons. The trophic level (TROPH) was high (3.66 < TROPH < 3.97), corresponding to carnivorous character

Composition et variation du peuplement ichtyologique de l’herbier superficiel à Posidonia oceanica (L.) Delile, dans la baie d’Annaba (Algérie)

Summary. — Composition and variations of the fish assemblage of Posidonia oceanica (L.) Delile, seagrass meadows in Annaba bay (Algeria). — During an annual cycle (July 2004 -June 2005), two coastal sites, one far away from anthropic action (site A : Aïn Achir) and the other subjected to immediate discharge of waste water (site B : la Caroube), were sampled during the day (8 h -18 h) and by night (19 h -7 h), with a net (50 m long, 2 m high) located at a depth of -5 m. According to the frequency of fish species captured, their ecological status was determined. The Shannon-Weaver diversity index (H’) was calculated to better understand the structure and organization of fish assemblages in both sites. In site A, 19 species belonging to 8 families were fished during the day. At night, the fish assemblage was represented by 15 species and 9 families. The family Sparidae was the most diversified, followed by Labridae and Serranidae. Labridae were the most numerous family by day and by night. Numbers of species and individuals collected in site B during the day (16) as well as by night (11) were significantly lower than those of site A. During daytime, diversity (H’) and equitability (R) indices were respectively 2.51 and 0.33 in site A and of 2.87 and 0.43 in site B. At night, diversity index was lower (site A : 0.64 and site B : 2.55) and equitability was close to 0.41 in the two sites.Résumé . — Au cours d’un cycle annuel (juillet 2004 -juin 2005), deux sites côtiers, l’un éloigné de l’action anthropique (site A : Aïn-Achir) et l’autre recevant les rejets directs des eaux usées de la ville d’Annaba (site B : la Caroube), ont été échantillonnés de jour et de nuit à l’aide d’un filet trémail. En fonction de sa fréquence, le statut écologique de chaque espèce a été déterminé. L’indice de diversité biologique de Shannon-Weaver (H’) a été calculé pour mieux comprendre la structure et l’organisation du peuplement de poissons dans les deux sites. Dans le site A, 19 espèces appartenant à 8 familles ont été pêchées de jour. La nuit, le peuplement ichtyologique est représenté par 15 espèces et 9 familles. La famille des Sparidés est la plus diversifiée, suivie de celle des Labridés et des Serranidés. Les Labridés sont les mieux représentés numériquement, aussi bien de jour que de nuit. Dans le site B, les nombres d’espèces et d’individus capturés, aussi bien de jour (16 espèces) que de nuit (11 espèces), sont nettement inférieurs à ceux obtenus dans le site A. De jour, les indices de diversité (H’) et d’équitabilité (R) sont respectivement de 2,51 et de 0,33 dans le site A et de 2,87 et de 0,43 dans le site B. La nuit, l’indice de diversité est plus faible (site A : 0,64 ; site B : 2,55) et l’équitabilité est proche de 0,41 dans les deux sites.Derbal Farid, Kara Mohamed Hichem. Composition et variation du peuplement ichtyologique de l’herbier superficiel à Posidonia oceanica (L.) Delile, dans la baie d’Annaba (Algérie). In: Revue d'Écologie (La Terre et La Vie), tome 65, n°2, 2010. pp. 139-149

Neobična pristunost juvenilnih primjeraka vrste Synagrops japonicus u jugozapadnom Mediteranu

This paper reports additional records of the Indo-Pacific fish Synagrops japonicus (Doderlein, 1884) in Western Mediterranean. Twenty juveniles of this species ranging from 4 to 4.8 cm (TL) were caught in Annaba Bay, Algeria, using beach seine, in Summer of 2011 (9 specimens, 4 ≤ TL ≤ 4.6 cm) and 2012 (11 specimens, 4.2 ≤ TL ≤ 4.8 cm). Some hypotheses on the origin of this unusual presence are discussed.U ovom radu se navode dodatni nalazi vrste Synagrops japonicus (Doderlein, 1884) u zapadnom Mediteranu. Uhvaćeno je dvadeset juvenilnih primjeraka ove vrste u rasponu od 4 do 4,8 cm (TL) u Annaba zaljevu, Alžir, pomoću obalne mreže potegače, u ljeto 2011. godine (9 primjeraka, 4 ≤ TL ≤ 4,6 cm) i 2012. (11 primjeraka, 4.2 ≤ TL ≤ 4,8 cm). U radu su iznesene neke hipoteze o podrijetlu ove neobične prisutnosti

Caractéristiques écologiques et biologiques d’Artemia salina (Crustacé, Anostracé) de la Sebkha Ez-Zemoul, Algérie nord-est.

Summary. — Ecological and biological characteristics of Artemia salina (Crustacea, Anostraca) in the sebkha Ez-Zemoul, northeastern Algeria. — This study concerned some biological and ecological aspects of Artemia salina (Branchiopoda, Anostraca) from the sebkha Ez-Zemoul, situated in northeastern Algeria (35° 53’ N -06° 30’ E). The survey of the demographic structure and density of Artemia population between January 2003 and February 2005 shows that this brine shrimp appeared in November after the cyst hatching, reached a maximum density in March (56 ind. L-1 in 2003 and 38 ind. L-1 in 2004) and disappeared completely in July. The sex ratio was always in favour of males. Its values were very high (1.77 -31.80). Males were smaller than females. Their respective lengths varied, according to the sampling period, between 7.1 mm and 8.8 mm and between 8.7 mm and 10.4 mm. The length of females at first sexual maturity varied between 7 mm (November) and 9 mm (April). Oviparity was the main mode of reproduction (90 -100 %). Females were relatively fertile with an average brood size comprised between 19.50 (May 2003) and 104.7 (March 2003) offsprings/ female.Résumé. — Cette étude est consacrée à quelques aspects de l’écologie et de la biologie d’Artemia salina (Branchiopode, Anostracé) de la sebkha Ez-Zemoul, située dans le nord-est de l’Algérie (35° 53’ N -06° 30’ E). Le suivi de sa structure démographique et de sa densité, entre janvier 2003 et février 2005, montre que ce crustacé apparaît en novembre, suite à l’éclosion des cystes, atteint une densité maximale en mars (56 ind. L-1 en 2003 et 38 ind. L-1 en 2004) et disparaît complètement à partir de juillet. La sex-ratio est toujours en faveur des mâles et ses valeurs sont très élevées (1,77 -31,80). Ces derniers sont plus petits que les femelles. Les tailles moyennes des deux sexes varient, selon la période d’échantillonnage, entre 7,1 mm et 8,8 mm et entre 8,7 mm et 10,4 mm respectivement. La taille à la première maturité sexuelle des femelles varie entre 7 mm (novembre) et 9 mm (avril). L’oviparité est le principal mode de reproduction (90 -100 %). La fécondité varie entre 19,5 (mai 2003) et 104,7 zygotes/ portée (mars 2003).Amarouayache Mounia, Derbal Farid, Kara Mohamed Hichem. Caractéristiques écologiques et biologiques d’Artemia salina (Crustacé, Anostracé) de la Sebkha Ez-Zemoul, Algérie nord-est.. In: Revue d'Écologie (La Terre et La Vie), tome 65, n°2, 2010. pp. 129-138

Several Congruences Related to Harmonic Numbers

Let p be a prime greater than or equal to 5: In this paper, by usingthe harmonic numbers and Fermat quotient we establish congruencesinvolving the sums where H(m)k are the generalized harmonic numbers of ordermand En areEuler numbers.AMS (MOS) Subject Classification Codes: 11A07; 11B68KeyWords: Congruences, harmonic numbers, Fermat quotient

Заметка о явных формулах для многочленов Бернулли

For r 2 { 1; - 1; 1 2 } , we prove several explicit formulas for the n-th Bernoulli polynomial Bn (x), in which Bn (x) is equal to a linear combination of the polynomials xn, (x + r)n ; : : : ; (x + rm)n, where m is any fixed positive integer greater than or equal to nПри r 2 { 1; - 1; 1 2 } доказаны несколько явных формул для n-го многочлена Бернулли Bn (x), в котором Bn (x) равно линейной комбинации многочленов xn, (x + r)n ; : : : ; (x + rm)n, где m — любое фиксированное натуральное число, большее или равное

Enhancement of the capacitance properties and the photoelectrochemical performances of P3HT film by incorporation of nickel oxide nanoparticles

International audienceP3HT films were modified by incorporation of different amounts of nickel oxide (NiO). The nickel oxide powder was synthesized by chronoamperometry. The composites were further dissolved and deposited by the spin-coating method on indium-tin oxide (ITO) substrates. Effects of NiO content on the morphology structure and optical properties of P3HT films were investigated by means of XRD, SEM, AFM, and UV-Vis spectroscopy. Electrochemical and photoelectrochemical performances were evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), galvanostatic charge-discharge, and photocurrent measurements. Results show that NiO dispersed uniformly in P3HT thin films and modified the surface roughness and absorption of the deposited thin films. A remarkable improvement of photocurrent density and electrochemical capacitance is observed for an NiO content ranging between 1 and 10wt%. The specific capacitance obtained for P3HT alone is about 20.8Fg(-1), this value increases to 81.4Fg(-1)for the P3HT-NiO 10wt% composite film at 0.1-A/g current density