Manuel Carrillo - Academia.edu (original) (raw)

Papers by Manuel Carrillo

Mathematical Programming, 1977

A study was made of the global minimization of a general quasiconcave function on a convex polyhe... more A study was made of the global minimization of a general quasiconcave function on a convex polyhedron. This nonconvex problem arises in economies of scale environments and in alternative formulations of other well-known problems, as in the case of bilinear programming. Although not very important in our final results, a local minimum can be easily obtained. However, a major aspect is the existence of two families of lower bounds on the optimal functional value: one is provided by non-linear programming duality, the other is derived from a lexicographic ordering of basic solutions which allows the use of relaxation concepts. These results were exploited in a finite algorithm for obtaining the global minimum whose initial implementation has had encouraging performance.

Physiology & Behavior, 1998

CERDÁ -REVERTER, J. M., S. ZANUY, M. CARRILLO AND J. A. MADRID. Time course studies on plasma glu... more CERDÁ -REVERTER, J. M., S. ZANUY, M. CARRILLO AND J. A. MADRID. Time course studies on plasma glucose, insulin, and cortisol in sea bass (Dicentrarchus labrax) held under different photoperiodic regimes. PHYSIOL BEHAV 64(3) [245][246][247][248][249][250] 1998.-Daily variations of insulin, cortisol, and glucose are studied in animals adapted to two different photoperiodic regimes, with the intervals between feeding times and photoperiodic events kept constant. Data support the existence of a daily rhythm of plasma glucose which seems to be photoperiodic. In contrast, the daily patterns of insulin in sea bass seem to be mainly influenced by feeding time; however, an effect of photoperiod can not be excluded. When the digestive tract is absent of food, insulin levels are generally minimal at feeding times and maximal during the inter-meals periods, suggesting the central control of insulin secretion during short-term food deprivation. Contrarily, the nadir values of plasma cortisol were reached at midday during the inter-meal period and peak plasma levels were evident at both light onset and offset. Disruption between metabolite and hormone patterns suggest that they are under different controls. Such results could be explained under the existence of a multioscillator system, including a food entrainable oscillator in addition to the master light entrainable oscillator.

General and Comparative Endocrinology, 2000

were analyzed in the pituitary of male sea bass during sex differentiation and the first spawning... more were analyzed in the pituitary of male sea bass during sex differentiation and the first spawning season. Plasma levels of gonadotropin (GTH-2), testosterone (T), and 11-ketotestosterone (11-KT) were determined during the same periods. All GnRH forms were present in the pituitary. sbGnRH levels were 9-fold higher than cGnRH-II and 17-fold higher than sGnRH levels. The highest GnRHs levels were detected in November 1995, when fish were 9 months old and when the gonads started to differentiate. Levels of the three forms decreased and remained low during the first spawning season, with the exception of sbGnRH, which showed a significant increase in November 1996. Plasma GTH-2 levels were lowest in November 1995, later increasing 2.5 times during the next months. During the first spawning season, plasma GTH-2 levels peaked in December 1996, 1 month after the peak of sbGnRH. During sex differentiation, plasma T levels were high in November 1995 but decreased over the next months, while levels of 11-KT remained low and unchanged. During the first spawning season, both steroids peaked in January 1997. These results suggest a possible role for all three GnRH forms in achieving gonadal differentiation, while sbGnRH may be the most relevant form in the regulation of the first spawning season in male sea bass. Moreover, GTH-2 and 11-KT may play important roles in gonadal maturation, since plasma GTH-2 and 11-KT levels were high throughout the period of spermiation.

General and Comparative Endocrinology, 1990

Levels of plasma testosterone ('I) and 11-ketotestosterone (1 I-KT) in males and plasma 17P-estra... more Levels of plasma testosterone ('I) and 11-ketotestosterone (1 I-KT) in males and plasma 17P-estradiol (E3, 17a-20l3-dihydroxy4pregnen-3-one (17a,ZOP-diOH-P), and T in females were assayed by radioimmunoassay at monthly intervals throughout the sexual cycle of sea bass (Dicentrarchus labrax L.). 17a,20g-DiOH-P was maintained at low levels (below 1 t&ml) throughout the year, even during the spawning period (January-March). A biiodal seasonal pattern of plasma testosterone was observed. Plasma T and E, levels became significantly increased in December (advanced gametogenesis period) and then showed further increases during January and February (first half of the spawning period) in parallel with the growth of the vitellogenic oocytes. Multiple spawnings of individual females were also observed during the spawning period affecting the relative fecundity of the eggs. A possible role of E, on this behavior is discussed. In males, both plasma T and 1 I-KT initially increased in November and then showed further increasings during the rest of the period of gametogenesis (December) to reach their peak levels in the first half of the spawning period (end of January). These increased and sustained higher levels of plasma steroids coincided with the presence of spermiating males. A second peak of plasma testosterone appeared at the end of the postspawning period-beginning of the pregametogenesis period (May-June) both in males and females and their possible role with the preparation of the gonad for the next reproductive cycle is discussed. o 1990 Academic RCSS, IN.

Aquaculture, 2001

M. Carrillo . 0044-8486r01r$ -see front matter q 2001 Elsevier Science B.V. All rights reserved. ... more M. Carrillo . 0044-8486r01r$ -see front matter q 2001 Elsevier Science B.V. All rights reserved. Ž . PII: S 0 0 4 4 -8 4 8 6 0 1 0 0 7 7 4 -8 ( ) L. Rodrıguez et al.r Aquaculture 202 2001 235-248 236 ment, while 11-KT may act by stimulating spermatogenesis andror spermiation in juvenile male sea bass. Furthermore, the profiles of these reproductive hormones were altered by both expanded and compressed photoperiods, and first sexual maturation was advanced by at least 2 months. q

Journal of Experimental Zoology, 1994

Although many studies implicate sex steroids in the process of sexual differentiation, the exact ... more Although many studies implicate sex steroids in the process of sexual differentiation, the exact role played by these substances in lower vertebrates, especially teleost fish, is not clear, since it is not conclusively known whether sex steroids are the cause or an early consequence of sex differentiation. By hormonal manipulation and specific crossings, it is possible to produce all-female stocks of the otherwise gonochoristic chinook salmon (Oncorhynchus tshawytscha). These all-female stocks are an excellent model to study the effects of steroids on sexual differentiation since the genetic sex is known before the actual differentiation of the embryonic gonads takes place. In the present study, we show that treatment with a nonsteroidal inhibitor of aromatase, the enzyme that catalyzes the conversion from androgens to estrogens, for only 2 hours when the gonads were bipotent, caused genetic females to develop into normal males. Furthermore, these males had testes which were indistinguishable both in size and in structure from those of genetic males, and completed all the stages of spermatogenesis. At 2 years of age, these males produced viable sperm capable of inducing normal embryonic development when used to fertilize eggs, with a resulting all-female progeny. These results provide strong support for Yamamoto's theory (Yamamoto, '69) that androgens and estrogens are natural sex inducers in gonochoristic fish, and suggest that aromatase plays a pivotal role in the sex differentiation of salmon. Thus, by brief treatment with an aromatase inhibitor at a specific time in development, an organism was induced to develop a funtional, phenotypic sex different from its genetic sex. © 1994 Wiley-Liss, Inc.

Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology, 1995

Sea bass were fed a natural diet (ND) (trash fish) or two commercial diets (CD1 = 56% (P)rotein, ... more Sea bass were fed a natural diet (ND) (trash fish) or two commercial diets (CD1 = 56% (P)rotein, 11% (L)ipids; CD2 = 47% P, 7% L) during two consecutive reproductive cycles in order to assess the effects on the reproductive performance. CD1 and CD2 had lower energetic and PUFA (polyunsaturated fatty acids) content, especially n-3 fatty acids, with respect to ND. During the first spawning, the levels of sex steriods (17B-estradiol [E2] and testosterone IT], the percentage of good quality (i.e. buoyant) eggs and the hatching rates were similar between the ND and CD1 groups. Females fed CD2 did not show significant variations in E2 or T, and had few spawnings, low egg quality and no egg survival. At second spawning, the fish fed the commercial diets had reduced fecundity and egg viability, together with lower levels of E2 and T, altered patterns of plasma lipids and early presence of atresia in the ovary, with respect to the females fed ND. The present study provides evidence for the importance of dietary lipid for the reproductive processes in the sea bass. The data suggest that long-term dietary deficiences in n-3 fatty acids may affect the patterns of plasma lipids and may induce early gonadal atresia. For example, follicular atresia could reduce the production of gonadal steroids, the fecundity and the subsequent egg survival.

Journal of Fish Biology, 2001

Journal of Experimental Zoology, 1996

The role of gonadotropin-releasing hormone (GnRH) in spermiogenesis and spermiation is not well u... more The role of gonadotropin-releasing hormone (GnRH) in spermiogenesis and spermiation is not well understood. This study examined the effects of different modes of administration of a GnRH analog (GnRHa; [~-Ala',Pro~NEtl-mGnRH) on spermiation in the sea bass, Dicentrarchus labrax. Groups of sea bass received either GnRHa injection in saline (I; 25 Kgkg body weight [BW] or one of three types of GnRHa sustained release polymeric device: a fastreleasing implant (ethylene-vinyl acetate copolymer [EVAcl; 100 pgkg BW), a slower-releasing implant (ethylene-vinyl acetate copolymer [EVSL]; 100 pg/kg BW), or biodegradable microspheres (M; 50 p g k g BW). Total expressible milt was collected and assessed for volume, motility, and counts at various intervals for 44 days. Untreated males produced a total of 9.4 k 3.4 ml/kg BW (mean rc_ SEM) of milt over the 44-day experimental period, with milt production ending by day 28. All GnRHa treatments stimulated a significant increase in total milt volume (mVkg BW) peaking by day 2 (I: 11.8 f 1.8) or day 7 (EVAc: 20.0 rc_ 1.5; M: 26.8 k 2.7; EVSL: 27.9 f 4.3) posttreatment.

Aquaculture, 1989

Carillo, M., Bromage, N., Zanuy, S., Serrano, R., and Prat, F., 1989. The effect of modifications... more Carillo, M., Bromage, N., Zanuy, S., Serrano, R., and Prat, F., 1989. The effect of modifications in photoperiod on spawning time, ovarian development and egg quality in the sea bass (Dicentrarchus labrux L.). Aquaculture, 81: 351-365. Under simulated natural conditions female sea bass (Dicentrurchus labrax) in eastern Spain (latitude 4O"N and longitude 0" ) spawned over a 6-8-week period in February and March, with 0044-8486/89,'$03.50 0 1989 Elsevier Science Publishers B.V. M. CARRILU) ET AL.

Fish Physiology and Biochemistry, 2000

A specific immunoassay was developed for the quantification of testosterone (T) in sea bass plasm... more A specific immunoassay was developed for the quantification of testosterone (T) in sea bass plasma. Specific primary antibody against T was produced using an antigen BSA conjugated with T. The enzyme immunoassay (EIA) had a sensitivity of 5–0.009 ng ml−1 and 6.2% intra-assay variation; inter-assay variation was 9.5% for sea bass plasma. The effects of two different accelerating photoperiod regimes, compressed photoperiod (CO; 6 months), and constant short photoperiod (9L:15D) with a long photoperiod (15L:9D) in March (SLmar), on T plasma levels and sexual maturation were examined during the onset of puberty in male sea bass. Natural photoperiod (NP) and SLmar groups exhibited the highest T values in December (8.69±1.03 and 10.85±1.04 ng ml−1, respectively). However, SLmar group showed the first significant decrease in T plasma levels in January, two months earlier than the NP group, which presented elevated T levels until February. The CO group displayed two significant T peaks, one in October (8.90±1.60 ng ml−1) and the other in January (9.60±1.10 ng ml−1). Gonadosomatic index (GSI) in the NP and SLmar groups displayed the highest values from December to February (>2.5%). However, the SLmar group showed the first significant increase in GSI in November, one month before the controls, indicating a clear advancement of gonadal development with respect to the NP group. In the CO group, a bimodal pattern was observed with two peaks, one in October–November (1.30±0.25%) and the second in March–April (0.97±0.33%) (PPP

Comparative Biochemistry and Physiology B-biochemistry & Molecular Biology, 2002

Journal of Fish Biology, 1997

Fish Physiology and Biochemistry, 1986

The present work investigates the importance of day length and temperature in the control of repr... more The present work investigates the importance of day length and temperature in the control of reproduction of sea bass, as well as the effectiveness of LHRHa and HCG in inducing spawning out of season in this species. A controlled regime was produced and seasonal cycles with high components of temperature and photoperiod were extended from the summer solstice for at least 6 months, followed by a short photoperiod regime for 3 months before a new increase in these components. Natural spawning in the control fish occurred more frequently in mid February, although it was also observed in January and early March. Temperature manipulation delayed the spawning one month with respect to the controls, although some of the animals entered into gonadal regression. Photoperiodic manipulation delayed maturation for three months with respect to controls but it was necessary to perform hormonal induction of spawning. Although LHRHa and HCG were both applied, only intraperitoneal injections of LHRHa were effective in inducing spawning of sea bass out of season when the temperatures were 17°C. Dephasing between the annual changes in photoperiod in relation to the coordination of the different events of the sexual cycle of sea bass is considered.

Aquatic Living Resources, 1995

This work examines the effects of constant long and short days on the hormonal profile of plasma ... more This work examines the effects of constant long and short days on the hormonal profile of plasma 17p-oestradiol (E2) levels and the ovarian vitellogenic events, as well as on the fecundity, time of spawning and egg quality of sea bass. Constant short days first administered in April advanced spawning (by 45 days on average) whereas exposure to constant long days from the same date induced a delay (averaging 38 days) compared to controls reared on an ambient light regime (Lat. 40°N). These light regimes produced shifts in the profiles of plasma 17p-oestradiol and in the percentage of the vitellogenic oocytes according to the spawning time of the respective groups. Relative fecundity of the short day group was similar to controls (257,000 versus 230,000 eggsikg spawned female, respectively). However, in the long day group, relative fecundity was reduced to one half that of control fish (124,000). Plasma oestradiol showed a bimodal pattern under long days and vitellogenetic and atretic oocytes were present for a longer period (6-7 months compared to 4-5 months in controls). In summary, in this paper we describe, for the first time in the sea bass, the effect of constant photoperiod regimes on the 17p-oestradiol plasma profiles, the timing of spawning and the quality of the eggs.

Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1994

In sea bass (males and non-vitellogenic females) estradiol (~) treatment caused the appearance in... more In sea bass (males and non-vitellogenic females) estradiol (~) treatment caused the appearance in the bloodstream of a new protein that was identified as the vitellogenin (VTG) molecule for this teleost species. The molecular weight of the sea bass VTG (445 kDa) and its amino acid composition was similar to that of other teleosts. VTG was purified by double-step chromatography and then used to obtain specific antibodies. The localization of VTG in the liver and in the ovary was carried out by immunocytochemistry. The effects of the E2 treatment on the synthetic activity of the liver were studied throughout the modifications observed at the histological and biochemical levels.

Aquaculture, 1999

Corresponding author. 0044-8486r99r$ -see front matter q 1999 Elsevier Science B.V. All rights re... more Corresponding author. 0044-8486r99r$ -see front matter q 1999 Elsevier Science B.V. All rights reserved.

Aquatic Living Resources, 1994

Adult two-year-old broodstock sea bass (Dicentrarchus labrax), raised in captivity, were fed ad l... more Adult two-year-old broodstock sea bass (Dicentrarchus labrax), raised in captivity, were fed ad libitum a natural diet (trash fish) until the end of their first spawning, and maintained under natural conditions of light and temperature. Six months before the second spawning, fish were randomly separated in two tanks with running sea water (salinity 37X0/,, pH 8.3) and maintained under similar environmental conditions. Fish were fed two different ration levels: group F, 1.04%, and group H, 0.45% body weightlday. The IOW ration supplied affected broodstock growth as indicated by decreased growth rates in weight and condition factor in group H, when compared to group F. The mean fecundity per female (No. eggslfemale) in group H fish was similar to that from F group, while the relative fecundity (No. eggslkg female) was more elevated in the H group. However, group H showed a delay in spawning time and slightly higher number of spawnings per female and larger spawning period, when compared to group F fish. In addition, group H females had reduced 17B-estradiol (E2) plasma levels and presented vitellogenic oocytes in the ovary a month later than group F females. By contrast, the vitellogenin (VGT) plasma levels remained similar between groups over the reproductive cycle. The egg quality (i.e. percentage of buoyant eggs), the egg biochemical composition and larval sunival at hatching were similar between the two groups. The larvae from both groups also exhibited the same sumival after 40 days of culture, although group H produced smaller eggs that yielded smaller newly-hatched lanae. Although the low ration supplied significantly reduced the growth and E2 plasma levels of sea bass, these preliminary results suggest that these changes do not dramatically affect the egg viability or the survival of larvae 46 days after hatching. Effets du rationnement alimentaire chez le bar, Dicentrarchus labrax, sur le taux d'oestrogène et de vitellogénine du plasma, sur la fécondité et la survie des larves: observations préliminaires. Des géniteurs du bar (Dicentrarchus labrax) âgés de deux ans et élevés en captivité, ont été nourris ad libitum avec un aliment naturel (du poisson, Boops boops) jusqu'à la fin de leur première ponte. Les poissons ont été maintenus dans des bacs de 8 m3 alimentés en eau de mer (salinité 37,8"/,, pH 8,3) et dans des conditions naturelles de température et de photopériode. Six mois avant leur deuxième ponte, les poissons ont été séparés en deux groupes et nourris avec deux types d'alimentation (le groupe F: I,04 %, et le groupe H: 0,45 % du poids vifljour, dans les mêmes conditions. La ration la plus faible fournie aux géniteurs a entraîné une diminution de leur taux de croissance ainsi que de leur facteur de condition. La fécondité moyenne par femelle (nombre d'oeufs par femelle) chez les poissons du groupe H, a été similaire à celle du groupe F, tandis que la fécondité relative (nombre d'oeufs par kgtpoids vif) a été plus élevée Aquat. Living Resour. ISSN 0990-7740194/04/$ 4.0010 IFREMER-Gauthier-Villars J. Cerdii et al.