Fertility and survival of Swedish Red and White × Holstein crossbred cows and purebred Holstein cows.

Swedish Red and White × Holstein (S×H) cows were compared with pure Holstein (HOL) cows for fertility and survival traits in 2 commercial dairy farms in central-southern Córdoba province, Argentina, over 6 years (2008-2013). The following traits were evaluated: first service conception rate (FSCR), overall conception rate (CR), number of services per conception (SC), days open (DO), mortality rate, culling rate, survival to subsequent calvings, and length of productive life (LPL). The data set consisted of 506 lactations from 240 S×H crossbred cows and 1,331 lactations from 576 HOL cows. The FSCR and CR were analyzed using logistic regression, DO and LPL were analyzed using a Cox's proportional hazards regression model, and differences of proportions were calculated for mortality rate, culling rate, and survival to subsequent calvings. The S×H cows were superior to HOL cows in overall lactations for all the fertility traits (+10.5% FSCR, +7.7% CR, -0.5 SC, and 35 fewer DO). During the first lactation, S×H cows were superior to HOL cows for all fertility traits (+12.8% FSCR, +8.0% CR, -0.4 SC, and 34 fewer DO). In the second lactation, S×H cows exhibited lower SC (-0.5) and 21 fewer DO than HOL cows. In the third or greater lactations, S×H cows showed higher FSCR (+11.0%) and CR (+12.2%), lower SC (-0.8), and 44 fewer DO than pure HOL cows. In addition, S×H cows had a lower mortality rate (-4.7%) and a lower culling rate (-13.7%) than HOL cows. Due to the higher fertility and lower mortality and culling rates, the S×H cows had higher survival to the second (+9.2%), third (+16.9%), and fourth (+18.7%) calvings than HOL cows. Because of these results, S×H cows had longer LPL (+10.3 mo) than HOL cows. These results indicate that S×H cows had higher fertility and survival than HOL cows on commercial dairy farms in Argentina.

Dietary restriction in sheep: Uterine functionality in ewes with different body reserves during early gestation.

The aim of this study was to characterize insulin, leptin and IGF-1 profiles after undernutrition in pregnant ewes with different initial body condition (iBCS) and to investigate embryo quality, uterine gene expression and presence and location of proteins during early gestation (day 5). Thirty-six Rasa Aragonesa ewes were divided into 2 groups with different BCS: BCS> 2.75 (high, H, n = 19) and BCS <2.25 (low, L, n = 17) and they were randomly assigned to two nutritional treatments: 1.5 maintenance (M) (control, C) or 0.5 (M) (undernourishment, U) times the daily maintenance requirements establishing four groups: high-iBCS control (HC, n = 9), high-iBCS undernourished (HU, n = 10), low-iBCS control (LC, n = 9) and low-iBCS undernourished (LU, n = 8). High-iBCS ewes presented higher concentration of IGF-1, reflecting a better metabolic status in these animals. There was a greater proportion of high-iBCS ewes presenting more than one CL (P < 0.05), and associated greater P4 plasma concentration, number of recovered embryo and a tendency for higher embryo viability rate (P = 0.13). In uterus, undernourished ewes tended to present lower P4 (P = 0.09) and higher E2 concentration (P = 0.10). Inmunostaining of uterine progesterone and estrogen receptors (PR and ERα) was not affected by iBCS and nutritional treatment. Ewes with low-iBCS tended to have more INSR mRNA, and undernourished ewes tended to have more IGFBP2 mRNA expression (P < 0.08). An interesting finding was that the uterine response to undernutrition was dependent on iBCS: a higher expression of GHR (P < 0.05) and a tendency in IGFBP5 (P = 0.09) mRNA was found in undernourished than control ewes but only in the high-iBCS group. In summary, the present study demonstrates that the endocrine response and the uterine gene expression to undernutrition depend on the initial body energy reserves (iBCS) and appears to be associated with a differential embryo quality.

Characterization of cellulose membranes modified with luminescent silicon quantum dots nanoparticles.

A highly hydrophilic planar membrane fabricated with regenerated cellulose (RC-4 membrane), a biocompatible polymer, was modified by inclusion of water-soluble silicon quantum dot nanoparticles (SiQDs). Both bare SiQDs and SiQDs coated with a PAMAM-OH dendrimer were employed in order to obtain luminescent and thermally stable membrane systems (RC-4/SiQDs and RC-4/SiQDs-PAMAM-OH membranes). Original and SiQDs-modified membranes were characterized by fluorescence spectroscopy (steady and confocal), derivative thermogravimetric analysis and impedance spectroscopy measurements. According to these results, both SiQDs-regenerated cellulose composite membranes present luminescent character as well as higher thermal resistance and conductivity than the original sample, although the dendrimer coverage of the SiQDs might partially shield such effects. Moreover, the permanence of SiQDs nanoparticles in the structure of the cellulosic support in aqueous environments and their effect on diffusive transport were determined by water uptake as well as by membrane potential measurements at different concentrations of a model electrolyte (KCl). These results demonstrate the possible use of these stable nano-engineered membranes, which are based on SiQDs nanoparticles, in electrochemical devices under flow conditions.

Extending the duration of treatment with progesterone and equine chorionic gonadotropin improves fertility in suckled beef cows with low body condition score subjected to timed artificial insemination.

The objective of this study was to evaluate the effect of an extended progesterone treatment on follicular development and fertility in postpartum, suckled beef cows subjected to timed artificial insemination (TAI). In experiment 1, cows (n = 24) with body condition score (BCS) ≥4.5 received either a 2-g progesterone intravaginal device on Day -23 or a 0.558-g progesterone intravaginal device on Day -9. Then, all cows received 2 mg of estradiol benzoate on Day -9; removal of the device, 1-mg estradiol cypionate, and PGF2α on Day -2; and TAI on Day 0. Metabolic status was assessed between Days -9 and -2. Ovarian structures and plasma progesterone were determined weekly from Day -23 to -9, daily from Day -9 to 0, and weekly until Day 28. In experiment 2, cows (n = 302) with BCS ≥4.5 received identical treatment to cows in experiment 1, but on Day -2, cows received 400 IU of two different commercial preparations of equine chorionic gonadotropin (eCG). Ovarian structures were determined on Days -23 and -9 on a subset of cows (n = 40). Pregnancy was determined 39 days after TAI. In experiment 3, multiparous cows (n = 244) with BCS <5.0 received identical treatment as cows in experiment 1 initiated on Day -18, and on Day -2, cows received 400 IU of eCG or no treatment. Ovarian structures were determined in a subset of cows (n = 31) on Days -3, -2, -1, 0, 1, and on Day 10. Pregnancy was determined 39 days after TAI. The results indicated that in experiment 1, plasma progesterone was higher in treated than nontreated (control cows) during the first 14 days (P = 0.0001). The extended progesterone treatment increased the size of the largest follicle between Days -23 and Day -5 (Group by Day, P = 0.04) and tended to increase the size of the dominant follicle from Day -5 to Day -1 (Group by Day, P = 0.06). There was no effect of metabolic status or interaction between metabolic status and day on follicular growth. In experiment 2, extended progesterone treatment tended to increase the size of the largest follicle between Day -23 and -9 (P = 0.06). There was no effect of Group, eCG, BCS, and parity on pregnancy per AI. In experiment 3, extended progesterone treatment combined with eCG increased the size of the dominant follicle (P = 0.01). Both extended progesterone treatment (P = 0.02) and eCG (P = 0.03) increased pregnancy per AI. In conclusion, an extended progesterone treatment stimulated follicular growth postpartum and improved fertility only in cows with low BCS.

Effect of exogenous melatonin on embryo viability and uterine environment in undernourished ewes.

The effect of exogenous melatonin on embryo viability in undernourished ewes was investigated. At lambing, 24 ewes were treated (+MEL) or not (-MEL) with a melatonin implant. After 45 days, both groups were fed to provide 1.5 (Control, C) or 0.5 (Low, L) times daily maintenance requirements, so that experimental groups were: C-MEL, C+MEL, L-MEL and L+MEL. Ewes were mated (Day 0) and on Day 5 embryos were recovered and classified according to their developmental stage and morphology. Ovaries were used for in vitro fertilization and uterine horns were processed to study progesterone and oestrogen receptor (PR and ERα) expression by inmunohistochemistry. After 21 days, groups L-MEL and L+MEL had an average weight loss of 10kg (P<0.001). Number of viable embryos per CL from L+MEL (0.50±0.2) was higher than from other groups (P<0.05). Overall, the melatonin effect was particularly evident in undernourished ewes, increasing both viability (L+MEL: 65%; L-MEL: 25%; P<0.05) and pregnancy rates (L+MEL: 66.6%; L-MEL: 16.6%; P<0.05). Neither nutrition and melatonin nor their interaction had a significant effect on the in vitro oocyte development. Melatonin treatment tended to increase the percentage of positive cells to PR in deep glandular epithelium, independently of diet (P=0.09), and the greatest staining intensity of PR was observed in the luminal and superficial glandular epithelia (P<0.0001). In conclusion, melatonin implants at lambing during the breeding season improve the viability of embryos recovered from undernourished ewes, although this effect seems not to be mediated at the oocyte competence level.

Psychological predictors for health-related quality of life in patients on peritoneal dialysis.

INTRODUCTION: It is currently recognized the impact of different clinical and sociodemographics variables on the health-related quality of life (HRQL) of patients undergoing peritoneal dialysis (DP), albeit the influence of psychological variable has not been thoroughly studied. The objective of this study is to identify the psychological predictors of HRQL in patients under DP. METHOD: 53 patients on DP participated in the study (49.54 ± 17.03 years, 54.7% women) in whom HRQL was evaluated by the Kidney Disease Quality of Life Short Form and it was obtained information related with psychological variables (depressive and anxious symptoms , alexithymia, health-related locus of control and coping strategies) besides socio-demographical and clinical variables. RESULTS: Patients on DP presented a worse HRQL than general population, particularly in the physical dimension. The comorbility, the number of visits to urgency department, previous hospital admissions, serum albumin and previous treatment with hemodialysis showed a negative impact on several dimensions of HRQL, but depressive symptoms, alexithymia and particularly anxious symptoms were the main determinants of the variability of HRQL in DP patients. We did not obtain a significant relationship between HRQL and the locus of control or the coping strategies. CONCLUSIONS: Among patients undergoing DP, anxiety, depression and alexithymia are important determinants of HRQL and they should be considered both in the evaluation and the treatment of this population of patients.

Repeated superovulation using a simplified FSH/eCG treatment for in vivo embryo production in sheep.

This study investigated the efficacy of a simplified repeated superovulation treatment (eCG plus FSH in a single dose, rather than the usual protocol of six decreasing doses of FSH) in the in vivo embryo production in Ojalada donor ewes during the breeding season. In vitro viability after vitrification and warming of embryos recovered from both treatments was also assessed. In addition, the study examined the effects of the concentration of anti-eCG antibodies before each eCG/FSH treatment on in vivo embryo production. Thirty-eight females at the end of their reproductive lives were given the decreasing (n = 19) or simplified (n = 19) superovulatory treatment up to three times at intervals of ≥ 50 d. The onset of estrus was 5 h earlier (P < 0.05) among ewes that received the eCG/FSH protocol (25.2 ± 0.80 h) than it was among those that received the decreasing superovulatory treatment (30.1 ± 1.0 h), but the two treatments did not differ significantly in ovulation rates or the number and viability of embryos recovered. Both of the superovulatory protocols were significantly (P < 0.05 to P < 0.01) less effective after the first application. After three superovulatory treatments, the average number of viable embryos per ewe was 14.1 ± 2.3 and 13.7 ± 2.5 in the decreasing and simplified protocols, respectively. High anti-eCG antibody concentrations just before the superovulatory treatment with eCG/FSH were associated with a significant decrease (P < 0.05) in the rates of fertilization, viability, and freezability, especially in the second and third recoveries. Repeated superovulatory treatments with eCG/FSH can provide an efficient means of producing high quality embryos in the ewes of endangered breeds at the end of their reproductive lives, although further studies are needed to characterize the response associated with high concentrations of anti-eCG antibodies.

Ultrasonographic imaging in small ruminant reproduction.

CONTENTS: Ultrasonography is a simple, reliable and non-invasive imaging technique without secondary effects. Application of ultrasonography in veterinary practice, and specifically in small ruminants, has developed to become the most efficient diagnostic tool for managing reproduction. The objectives of current revision are to offer an overview, after a short reminder of equipment and techniques for imaging genitalia in small ruminants, of the uses and utility of ultrasonography for the evaluation of physiological and pathological conditions in males and females and for the application of assisted reproductive technologies.

Effects of exogenous melatonin on in vivo embryo viability and oocyte competence of undernourished ewes after weaning during the seasonal anestrus.

This study investigated the effects of exogenous melatonin on embryo viability and oocyte competence in post-partum undernourished ewes during the seasonal anestrus. At parturition (mid-Feb), 36 adult Rasa Aragonesa ewes were assigned to one of two groups: treated (+MEL) or not treated (-MEL) with a subcutaneous implant of melatonin (Melovine(R), CEVA) on the day of lambing. After 45 d of suckling, lambs were weaned, ewes were synchronized using intravaginal pessaries, and fed to provide 1.5x (Control, C) or 0.5x (Low, L) times daily maintenance requirements. Thus, ewes were divided into four groups: C-MEL, C+MEL, L-MEL, and L+MEL. At estrus (Day=0), ewes were mated. At Day 5 after estrus, embryos were recovered by mid-ventral laparotomy and classified based on their developmental stage and morphology. After embryo collection, ovaries were recovered and oocytes were classified and selected for use in in vitro fertilization (IVF). Neither diet nor melatonin treatment had a significant effect on ovulation rate and on the number of ova recovered per ewe. Melatonin treatment significantly improved the number of fertilized embryos/corpus luteum (CL) (-MEL: 0.35 +/- 0.1, +MEL: 0.62 +/- 0.1; P = 0.08), number of viable embryos/CL (-MEL: 0.23 +/- 0.1, +MEL: 0.62 +/- 0.1; P < 0.01), viability rate (-MEL: 46.6%, +MEL: 83.9%; P < 0.05), and pregnancy rate (-MEL: 26.3%, +MEL: 76.5%; P < 0.05). In particular, exogenous melatonin improved embryo viability in undernourished ewes (L-MEL: 40%, L+MEL: 100%, P < 0.01). Neither nutrition nor exogenous melatonin treatments significantly influenced the competence of oocytes during IVF. Treatment groups did not differ significantly in the number of healthy oocytes used for IVF, number of cleaved embryos, or number of blastocysts and, consequently, the groups had similar cleavage and blastocyst rates. In conclusion, melatonin treatments improved ovine embryo viability during anestrus, particularly in undernourished post-partum ewes, although the effects of melatonin did not appear to be mediated at the oocyte competence level.

Effects of treatment with a prostaglandin analogue on developmental dynamics and functionality of induced corpora lutea in goats.

The aim of this study was to compare morphological and functional features of spontaneous and induced corpora lutea (CLs) in goats. Fourteen adult and cycling Anglo Nubian goats (Argentina) were randomly allocated to two groups: Group N (n=7) included goats with natural spontaneous oestrus and Group PG (n=7) included does in which oestrus was synchronized by the administration of two i.m. cloprostenol doses, 10 days apart. In both groups, oestrous behaviour was checked twice daily (Day of oestrus=Day 0) and daily transrectal ultrasonographies were performed for evaluating CLs and follicles dynamics through the complete subsequent oestrous cycle; the luteal activity was determined directly, in terms of progesterone (P4) secretion, and indirectly, by assessing effects of CL on follicular dynamics. All goats exhibited oestrous behaviour and ovulation without differences in ovulation rate (N: 1.67+/-0.2, PG: 2.0+/-0.1). The total luteal tissue area showed linear growth from Day 4 to Day 15 of oestrous cycle in all goats, but the developmental dynamics differed between groups, treated goats had larger area (P<0.01). Plasma P4 concentrations also increased from Day 0 to Day 15 in all the does; however, from Day 5 to Day 15, treated does had a lower concentrations than the untreated group (P<0.001). There were differences in the development of follicular waves between groups; assessment of size-distribution showed that treated group had a higher number of small and larger follicles (P<0.05). The largest follicles recorded in treated goats had a higher maximum diameter both at the first (PG: 7.6+/-0.8mm; N: 4.9+/-0.7 mm, P<0.05) and second follicular waves (PG: 6.3+/-1.4mm; N: 5.0+/-0.4mm, P<0.05) and a longer growth phase during the second wave (PG: 6.5+/-1.7 days; N: 4.6+/-0.7 days, P<0.05), coincident with the period of maximal luteal secretion. In conclusion, synchronization of oestrus and ovulation by the administration of a prostaglandin analogue causes differences in developmental dynamics and functionality of induced corpora lutea when compared to natural spontaneous ovulation.

Undernutrition and exogenous melatonin can affect the in vitro developmental competence of ovine oocytes on a seasonal basis.

This study evaluated the effects of exogenous melatonin and level of nutrition on oocyte competence, in vitro fertilization (IVF), and early embryonic development in sheep during seasonal anoestrus (SA) and the reproductive season (RS). Adult Rasa Aragonesa ewes were assigned randomly to one of four treatment groups in two experiments based on a 2 x 2 x 2 factorial design. Individuals were treated (+MEL) or not treated (-MEL) with a subcutaneous implant of melatonin for 42 days and then were fed 1.5 (Control, C) or 0.5 (Low, L) times the daily maintenance requirements for 20 days. Ewes were synchronized and mated at oestrus (Day = 0). On Day 5, ovaries were collected and oocytes were used for IVF. Season had a significant (p < 0.01) effect on the number of oocytes recovered (RS: 19.6 +/- 1.0; SA: 14.5 +/- 1.0) and the number of healthy oocytes (RS: 13.9 +/- 0.7; SA: 9.0 +/- 0.7). In the RS, neither nutrition nor melatonin had a significant effect on the evaluated oocytes quality parameters although melatonin implants appeared to reduce the number of unhealthy oocytes in the undernourished group (p < 0.05). During SA, in undernourished ewes exogenous melatonin tended to increase the number of healthy (L+MEL: 9.4 +/- 1.0, L-MEL: 7.6 +/- 1.4; p < 0.1), and significantly improved both cleaved oocytes (L+MEL: 7.0 +/- 0.7, L-MEL: 4.1 +/- 0.9; p < 0.05) and blastocyst rate (L+MEL: 37.2, L-MEL: 21.9%; p < 0.05). In conclusion, oocyte competence in ewes was affected by season, and melatonin implants appeared to improve developmental competence in the seasonal anoestrous period, particularly in experimentally undernourished ewes.

Effect of undernutrition on the uterine environment during maternal recognition of pregnancy in sheep.

The effects of pregnancy and undernutrition on endometrial gene expression were investigated in ewes fed all or half their maintenance requirements and killed on Day 14 of pregnancy or of the oestrous cycle. The endometrial expression of progesterone, oestrogen, oxytocin and interferon receptors (PR, ERalpha, OXTR and IFNAR, respectively), cyclo-oxygenase (COX)-2, proliferating cell nuclear antigen (PCNA), insulin-like growth factors (IGF)-I and -II, and IGF-1 receptor (IGF-1R) was studied by immunohistochemistry or real-time reverse transcription-polymerase chain reaction. The luminal epithelium of cyclic control ewes was devoid of PR staining and had relatively high levels of ERalpha, OXTR, COX-2 and IFNAR2. The presence of a conceptus decreased the in vitro uterine secretion of prostaglandin (PG) F(2alpha) and the expression of IFNAR2 in most cell types, and increased the gene expression of IGF-I and IGF-II. Undernutrition tended to increase ERalpha protein and gene, but decreased in vitro uterine secretion of PGE(2) and the gene expression of IFNAR2 in cyclic ewes. There was no effect of undernutrition on pregnancy rates or the number of conceptuses recovered. Consistent with this, undernutrition of pregnant ewes did not have any effect on uterine gene expression. Moreover, in cases where changes were observed in cyclic ewes, these changes were negated when a conceptus was present.

Effects of melatonin and undernutrition on the viability of ovine embryos during anestrus and the breeding season.

This study examined the effects of melatonin and level of nutrition on embryo yield during anestrous and breeding season. Adult Rasa Aragonesa ewes were assigned randomly to one of the four treatment groups in two experiments using a 2x2x2 factorial design. Individuals were treated (+MEL) or not treated (-MEL) with a subcutaneous implant of melatonin for 42d (Melovine, CEVA) and fed 1.5 (control, C) or 0.5 (low, L) times the daily maintenance requirements for 20d. Ewes were mated at oestrus (Day=0) and embryos were recovered on Day 5. Level of nutrition and melatonin supplements did not have a significant effect on ovulation rate or the number of recovered ova per ewe in the Reproductive Season (RS) and the Anestrous Season (AS). During the RS, undernutrition reduced the number of viable embryos per ewe (C: 1.1+/-0.2; L: 0.6+/-0.2; P<0.05); however, the number of viable embryos per ewe in the L+MEL group (0.2+/-0.15) was significantly lower than it was in the L, C+MEL and C groups (0.9+/-0.3, 1.2+/-0.3, 1.0+/-0.4, respectively; P<0.05). In the AS, nutrition did not have a significant effect on the number of viable embryos per ewe, although melatonin supplements might have improved rates slightly. Embryo viability rate (% viable embryos/embryos recovered) was unaffected by melatonin supplements or level of nutrition in the RS and the AS. Season had a strong effect on the number of viable embryos per functional corpus luteum among ewes in the L+MEL group, only (RS: 0.2+/-0.1; AS: 0.6+/-0.2; P<0.05). In conclusion, undernutrition impaired the viability of sheep embryos in the RS, particularly among ewes that were given melatonin supplements subcutaneously, but melatonin appeared to improve embryo quality in the AS, which suggests that the mechanisms involved in the interactive effects of melatonin and nutrition on embryo development are influenced by season.

Chemical surface, diffusional, electrical and elastic characterizations of two different dense regenerated cellulose membranes.

A comparison of NaCl transport across two dense cellulosic membranes from different suppliers is presented. Hydraulic and diffusional permeabilities were determined from volume flow-applied pressure and concentration-time relationships, while cation transport number and membrane conductivity were determined from electromotrice force and impedance spectroscopy measurements, respectively. Chemical surface differences between both membranes are correlated to transport parameters and morphology, but differences in elastic properties of both membranes might also be considered in order to get a more complete picture of membrane behaviors and to obtain structural-transport parameters correlations.

[A smoking cessation program for prison inmates and personnel]. / Programa de deshabituación tabáquica para internos y trabajadores de un centro penitenciario.

The main aim of this initiative is to promote a culture change in the prison/tobacco conjunction by means of an intervention program that leads to reduction in the high levels of smoking amongst the prison population (70-80%) and prison personnel. We hope to demonstrate that it is possible in practice to successfully implant and extend tobacco cessations programs in prisons. This would mean an important step forward for the general health of prison inmates, who suffer from higher levels of tobacco addiction than the general population and prison staff, who for their part are forced to share a reduced and enclosed space with prisoners.

Programa de deshabituación tabáquica para internosy trabajadores de un centro penitenciario / A smoking cessation program for prison inmates and personnel

El principal objetivo de esta iniciativa es promover un cambio de cultura en torno al binomio cárcel y tabaco medianteun programa de intervención que conduzca a una reducción del elevado porcentaje de tabaquismo entre la población interna,70 a 80 %, y los trabajadores del medio penitenciario.Queremos demostrar, en la práctica, que es posible implantar y generalizar con éxito programas de abandono de la dependenciadel tabaco en los Establecimientos penitenciarios. Esto supone un paso importante en la mejora de la salud globalde los internos que sufren una mayor prevalencia de tabaquismo que la población general y de los trabajadores penitenciarios,que comparten con ellos un espacio reducido y cerrado (AU)

The main aim of this initiative is to promote a culture change in the prison/tobacco conjunction by means of an interventionprogram that leads to reduction in the high levels of smoking amongst the prison population (70-80%) and prisonpersonnel.We hope to demonstrate that it is possible in practice to successfully implant and extend tobacco cessations programs inprisons. This would mean an important step forward for the general health of prison inmates, who suffer from higher levels of tobacco addiction than the general population and prison staff, who for their part are forced to share a reduced and enclosed space with prisoners (AU)

Modification of active and porous sublayers of aged polyamide/polysulfone composite membranes due to HNO3 treatment: effect of treatment time.

Changes in electrical and transport parameters for aged composite polyamide/polysulfone membrane samples (PAC) and their porous support layers (PSU) as a result of chemical treatment (immersion in 1 M HNO3 solution) at four different times (12 h < or = t < or = 72 h) have been obtained. Salt permeability, ion transport number, and membrane electrical resistance for the treated samples were determined from salt diffusion, membrane potential, and impedance spectroscopy measurements, which were carried out with the membranes in contact with NaCl solutions at different concentrations and compared with those determined for fresh and aged nontreated samples. Results show the strong effect of aging on membrane parameters, particularly the decrease in salt permeability (P(s)) and the increase in membrane electrical resistance (R(m)), while ion transport number is hardly affected by aging, chemical treatment, or treatment time. Results show how the compaction of the porous structure causes by aging (dried membrane matrix structure) can be partially reduced by HNO3 treatment, and they also allow the estimation of 24-h treatment as the optimum time (higher salt permeability and lower membrane electrical resistance), mainly for the polysulfone support layer. The use of equivalent circuits in the analysis of impedance spectroscopy data allows separate estimation of the electrical resistance associated with each sublayer of the composite PAC membrane samples. On the other hand, chemical changes in the active top layer of the PAC membrane (polyamide active layer) were obtained from XPS analysis, which show some modifications in the atomic concentration percentages of the polyamide characteristic elements as a result of acidic treatment time, which are more significant after 72-h acidic immersion.