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1.
Res Vet Sci ; 139: 177-185, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34333252

ABSTRACT

This work examined the effect of acute nutritional restriction or supplementation one week before male introduction on the reproductive performances of the "male effect" when using photostimulated or control males in goats. On 22 March, 84 anoestrous does were placed with photostimulated bucks or with bucks which had received no treatments. One week before male introduction, the females were provided with different nutritional regimes: Supplemented, restricted or control females. The non-esterified fatty acids (NEFAs) and Insulin Growth Factor-1 (IGF-1) concentrations were measured in the same samples. Fecundity, fertility, prolificacy and productivity were also determined. No interaction between both sources of variation was observed in any of the reproductive variables studied. Treatment of the bucks increased the percentage of females expressing behavioural oestrous associated with ovulation (71% vs 90% for Natural and Photo groups, respectively, P < 0.05). The Supplemented females showed higher ovulation rate than Restricted females (1.77 ± 0.13 vs 1.05 ± 0.05, P < 0.001), fecundity (71% vs 43%, P < 0.05); fertility (76% vs 29%, P < 0.05) and productivity (1.00 ± 0.15 vs 0.29 ± 0.11 kids per female, P < 0.01). In the Supplemented females, the higher reproductive results could be due to the lower NEFAs and higher IGF-1 concentrations at ovulation and at the time of oestrus compared to the Restricted females. Thus, the present experiment results demonstrate that nutrition is an important factor in the response to the "male effect" at Mediterranean latitudes, and its negative effect cannot be counterbalanced by using photostimulated bucks.


Subject(s)
Goats , Ovulation , Photoperiod , Animals , Estrous Cycle , Female , Male , Nutritional Status , Reproduction , Seasons , Sexual Behavior, Animal
2.
Ambio ; 49(10): 1658-1675, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32060791

ABSTRACT

Community involvement may be essential for conservation programme success. We focus on farmers, asking how and why they believe conservation interventions will work, or not. Here we test models of folk theories of the human motivational factors required for behaviour change, in 3 rural central Chilean communities. We hypothesize that different models will be supported by farmers with different experiences with conservation programmes, and that socioeconomic and production system variation will explain further variation in who supports each working model. We use a multiple methods approach, combining a questionnaire with participant-observation. We find support for three of the working models of human behavioural change, among different socio-economic profiles of farmers. We believe that the schema of working models provides a boundary object to facilitate communication between conservationists and stakeholders, and can help improve conservation project design and implementation.


Subject(s)
Farmers , Motivation , Agriculture , Chile , Community Participation , Humans , Surveys and Questionnaires
3.
Anim Reprod Sci ; 202: 58-64, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30717994

ABSTRACT

The aim of this study was to examine whether photoperiod-treated bucks have the same capacity as melatonin-treated bucks to induce reproductive responses in female goats during the spring. On 10 April, 38 anoestrous does were placed with: 1) photoperiod-treated bucks (additional light hours for 83 days from the end of the previous November; PHOTO; n = 12); 2) bucks treated with exogenous melatonin at the beginning of March (MEL; n = 13); and 3) bucks that received no treatments (CONTROL; n = 13). The bucks' sexual behaviour was assessed for 10 days, and doe oestrous behaviour was recorded for the next 32 days by checking for harness marks. Ovulation was confirmed from plasma progesterone concentration (measured twice per week) and ovulation rate was assessed by transrectal ultrasonography. Fecundity, fertility, prolificacy and productivity were also determined. The percentage of does in the PHOTO, MEL and CONTROL group: 1) having ovulations was 92%, 100% and 38% respectively; 2) expressing behavioural oestrous associated with ovulation was 92%, 100% and 31%; and 3) that became pregnant was 75%, 69% and 23%, respectively. The kids produced per doe were 1.08 ± 0.23, 1.15 ± 0.25 and 0.31 ± 0.17 for the PHOTO, MEL, and CONTROL groups, respectively with there being no differences between the PHOTO and MEL groups, however, there was a difference (P < 0.05) between PHOTO/MEL and CONTROL groups. Thus, imposing a stimulatory lighting regimen during the preceding winter period is as efficient as using subcutaneous melatonin implants in stimulating reproductive behaviours and physiological functions of bucks.


Subject(s)
Goats/physiology , Goats/psychology , Melatonin/pharmacology , Ovulation , Reproduction , Sexual Behavior, Animal/physiology , Animals , Antioxidants/pharmacology , Female , Male , Photoperiod , Pregnancy , Progesterone/blood
4.
Animal ; 13(8): 1658-1665, 2019 Aug.
Article in English | MEDLINE | ID: mdl-30621806

ABSTRACT

The exposure of adult, female, Mediterranean goats during anoestrus to males with induced sexual activity via photostimulation, induces a very high percentage of ovulations. The present work examines the ability of photostimulated bucks to improve the male effect-induced reproductive response of young does over that induced by non-stimulated bucks. A 2×2 factorial experiment was designed, consisting of doe age and buck photoperiod treatments. During seasonal anoestrus, 41 does aged 7 (n=19) or 10 (n=22) months were subjected to the male effect on 10 April; half of each group was exposed to males rendered sexually active by prior exposure to 3 months of long days (16 h of light/day) from 31 October (PHOTO bucks), and half to males maintained under the natural photoperiod (CONTROL bucks). Oestrous activity was recorded daily by direct visual observation of the marks left by male-worn marking harnesses over the 32 days following the bringing of the sexes together (introduction). Doe body weight and body condition were determined weekly. Ovulation was detected by measuring plasma progesterone concentrations twice per week over the 3 weeks after introduction. The ovulation rate was assessed by transrectal ultrasonography. Fecundity, fertility, prolificacy and productivity were also determined. The interaction doe age × buck photoperiod treatment had no effect on any outcome. The percentage of females showing ovulation or oestrus was higher in the does exposed to PHOTO bucks (85% v. 43% for those exposed to CONTROL bucks) they also showed higher fertility (75% v. 43%) and productivity (1.05±0.17 v. 0.57±0.16 kids born per doe serviced) (all P values at least P<0.05). The 10-month-old group showed higher percentage of females showing ovulation, oestrus, fertility and productivity than the 7-month-old does after the male effect (females showing ovulation: 82% v. 42%; showing oestrus: 73% v. 42%; fertility: 73% v. 42% and productivity: 1.09±0.17 v. 0.47±0.14 goat kids born per doe serviced; respectively, all P values at least P<0.05). The present results show that the use of photostimulated males improves the reproductive performance of 7- and 10-month-old does, and may contribute towards increasing their productivity and lifetime reproductive performance.


Subject(s)
Goats/physiology , Ovulation/physiology , Photoperiod , Seasons , Sexual Behavior, Animal/radiation effects , Animals , Body Weight , Estrus , Female , Fertility , Male , Progesterone/blood , Reproduction/physiology , Sexual Behavior, Animal/physiology
5.
Anim Reprod Sci ; 190: 75-84, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29402639

ABSTRACT

When the sexual activity of bucks is minimal, there is a minimal male effect on does regardless of their body weight (BW)/body condition (BC) and whether does are treated with melatonin or not. The study examines whether sexually active bucks can induce an adequate male effect in does with an increasing or decreasing trajectory of change in BW/BC when does are or not treated with melatonin. During natural anoestrus, 46 Blanca Andaluza does were assigned to two groups: 1) low BW/low BC group in which does were fed 1.9 times maintenance requirements for dietary energy for gaining BW/BC (LLg group; n = 23); or 2) a high BW/high BC group in which the does were fed 0.4 times maintenance requirements for dietary energy that resulted in a loss of BW/BC (HHl group; n = 23). There were similar numbers of does in each group that were treated or not treated with melatonin (MEL). Following 48 days of isolation from bucks, four sexually active individuals fitted with marking harnesses were transferred to the paddock containing the does of each group. Blood samples were collected by jugular venipuncture (before the distribution of concentrate) twice per week. The effect of the treatments (increasing or decreasing BW/BC and melatonin) on the different variables that were assessed were analysed using an ANOVA or the Fisher-Freeman-Halton exact probability test as necessary. During the 35 days after treatments were applied, the percentage of females expressing oestrous and having an ovulation were greater in the LLg + MEL than HHl-MEL subgroup (P < 0.05). The interaction of nutrition × melatonin treatment had a significant effect on reproduction of does (P < 0.05). This could be explained by the greater plasma glucose and IGF-1 and lesser plasma non-esterified fatty acid concentrations in does with increasing BW/BC (P < 0.01), and the greater IGF-1 concentrations of MEL-treated females (P < 0.01). The LH concentration and pulsatile release of this hormone from the pituitary were also modified by the presence of the males (P < 0.01). Furthermore, the LLg + MEL-treated does were responsive to the presence of bucks (P < 0.05). The present results indicate sexually active males cannot induce an adequate reproductive response in females with decreasing BW/BC even when does are being treated with melatonin. The presence of bucks enhanced the doe reproductive response when does were treated with melatonin and a pattern of increasing BW/BC.


Subject(s)
Body Composition , Body Weight , Goats/physiology , Melatonin/pharmacology , Sexual Behavior, Animal/drug effects , Animal Feed , Animal Nutritional Physiological Phenomena , Animals , Diet/veterinary , Drug Implants , Female , Male , Melatonin/administration & dosage , Nutritional Status , Seasons
6.
Theriogenology ; 95: 42-47, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28460678

ABSTRACT

It has been suggested that female goats in permanent contact with males become refractory to their presence, and need to be previously separated from them for 40-45 days if the presence of bucks is to induce reproductive activity, ovulation and oestrous during seasonal anoestrous. The present study examines the reproductive response (ovulation and oestrus) and reproductive performance of does isolated from bucks for different periods before their reintroduction to male company. A total of 103 Payoya and Blanca Andaluza does were distributed into six treatment groups that required their isolation from males for different periods: 0 days (N = 29), 5 days (N = 15), 10 days (N = 14), 20 days (N = 16), 30 days (N = 14) and 39 days (N = 15). After this period they were introduced to sexually active bucks (ensured to be in this condition by keeping them under long days light treatment for three months), and oestrous activity was recorded daily by direct visual observation of the marks left by the marking harnesses worn by these males. Ovulation was confirmed via the plasma progesterone concentration (measured in blood samples taken twice per week). The ovulation rate was assessed by transrectal ultrasonography. Fecundity, fertility, prolificacy and productivity were also determined. The sexual behaviour of the males towards the females was also monitored on Days 0, 1, 2, 3, 4, 8 and 9 after their meeting with the latter. The length of the female isolation period had no effect on the percentage of does that responded to contact with the males, nor did it affect the oestrous response, fecundity, fertility or productivity. The males, however, undertook more ano-genital sniffing and nudging with the 5 day group females compared to those of the other groups (P < 0.05). However, the sexual behaviour of the males changed as the days passed, with ano-genital sniffing becoming less common, and nudging, licking, sneezing and mounts with intromission more frequent on Days 8 and 9 than on Day 0, 1 and 2 after the sexes were reunited (P < 0.05). These results show that the isolation of females is not necessary for an efficient male effect if the bucks used are sexually active. In addition, the sexual behaviour of the bucks changes as the time in contact with the does increases, but in general is not affected by the duration of female isolation.


Subject(s)
Goats/physiology , Sexual Behavior, Animal/physiology , Animals , Estrus/physiology , Female , Fertility , Male , Ovulation/physiology , Photoperiod , Progesterone/blood
7.
Anim Reprod Sci ; 179: 57-66, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28189349

ABSTRACT

The aim of the present work was to determine whether treatment with melatonin modifies the reproductive response of female goats experiencing increasing or decreasing body weight (BW)/body condition score (BCS) when introduced to bucks displaying springtime sexual activity. During natural anoestrus, 53 does were isolated from bucks for a period of 42days and distributed into two groups: 1) low BW/low BCS animals (N=24) (LLg group), which were fed 1.9 times their maintenance requirements so they would experience increasing BW and BCS; and 2) high BW/high BCS animals (N=29) (HHl group), which were fed 0.4 times their maintenance requirements so they would experience decreasing BW and BCS. Half of each group was treated, or not, with melatonin (LLg+Mel N=12, HHl+Mel N=15, LLg-Mel N=12 and HHl-Mel N=14). On 6th May they were introduced to six males, showing natural sexual activity, fitted with marking harnesses (thus permitting the detection of oestrous activity). The ovulation rate was assessed by transrectal ultrasonography and confirmed via the plasma progesterone concentration (measured twice per week in blood samples). Plasma glucose, IGF-1 and non-esterified fatty acid concentrations were also determined, along with the conception rate, fertility, prolificacy and productivity of the does. LH concentrations and LH pulsatility were also recorded in the hours around introduction to the males. 'Oestrous plus ovulation' was observed only in does treated with melatonin. A higher conception rate and greater fertility and productivity were observed among the LLg+Mel does. These females showed higher glucose and IGF-1 concentrations after the introduction of the males. LH concentrations increased after male introduction independent of all other conditions. In conclusion, the present results show that treatment with melatonin does not enhance reproductive performance in does experiencing decreasing BW/BCS, but can improve it when does are experiencing increasing BW/body fat reserves - even when exposed to males displaying only springtime sexual activity. This might be explained by the higher blood glucose and IGF-1 concentrations of the LLg+Mel females.


Subject(s)
Body Composition/physiology , Body Weight/physiology , Melatonin/pharmacology , Reproduction/drug effects , Sexual Behavior, Animal/physiology , Animal Feed/analysis , Animal Nutritional Physiological Phenomena , Animals , Antioxidants/pharmacology , Blood Glucose , Diet/veterinary , Fatty Acids, Nonesterified/blood , Female , Male , Nutritional Status , Seasons
8.
Anim Reprod Sci ; 157: 24-32, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25840614

ABSTRACT

This paper compares the effects of exposure to exogenous melatonin (MEL), short days (SD, 8h of light) and long days (LD, 16 h of light), on reproductive activity, sperm motility and other reproductive variables, in Blanca Andaluza bucks. Fourteen males were spilt into two groups of seven animals (G1 and G2). They were subjected to five alternations of 2 months of LD followed by 2 months of SD or MEL before the experimental period of three consecutive intervals of: (1) 2 months of SD (G1, N=7) or MEL (G2, N=7); (2) 2 months of LD (G1+G2, N=14); and (3) 2 months of SD (G2, N=7) or MEL (G1, N=7). Plasma testosterone concentration, live weight, testicular weight and fresh semen quality were determined weekly. Semen was also cooled and frozen-thawed every fortnight, and the same quality variables measured as for fresh sperm. When the bucks were under LD treatment, the testosterone concentration was lower than when under MEL or SD treatment (P<0.01); values for the semen concentration and total number of sperm per ejaculate were also higher (P<0.001). No differences were observed between the MEL and SD treatments in terms of fresh, cooled or frozen-thawed sperm quality. Only some quality variables on fresh semen were improved by MEL and SD treatment (P<0.05). In conclusion the results of the present experiment showed that MEL improved the fresh semen motility variables, but this did not improve the motility of frozen-thawed sperm over that recorded for either SD or LD treatment.


Subject(s)
Freezing , Goats/physiology , Melatonin/pharmacology , Photoperiod , Semen Preservation/veterinary , Semen/drug effects , Animals , Male , Organ Size/radiation effects , Semen/physiology , Semen Preservation/methods , Sexual Behavior, Animal , Sperm Motility , Testis/anatomy & histology , Testis/radiation effects , Testosterone/blood , Time Factors
9.
Anim Reprod Sci ; 156: 51-7, 2015 May.
Article in English | MEDLINE | ID: mdl-25778745

ABSTRACT

This study examines the nutritional and metabolic cue-induced modulation of the reproductive performance response of female goats to the male effect. During natural anoestrus, 48 Blanca Andaluza does were isolated from bucks for 45 days and distributed into two groups: (1) low body weight (BW)/low body condition score (BCS) animals (LL-gain group, N=18), which were fed 1.9 times their maintenance requirements; and (2) high BW/high BCS animals (HH-loss group, N=30), which were fed 0.4 times their maintenance requirements. Following isolation, oestrous activity was recorded daily by visual observation of the marks left by harness-equipped males. Weekly blood samples were taken for the determination of progesterone, glucose, insulin, non-esterified fatty acids (NEFAs) and leptin concentrations. Fecundity, fertility, prolificacy and productivity were also determined. Significantly greater ovarian and oestrous responses, and productivity, were observed in the LL-gain group compared to the HH-loss group (P<0.05). After the introduction to the males, no differences in NEFA concentration were seen between the groups; before introduction the values were higher in the HH-loss group. At the moment of detection of oestrus following male introduction, the insulin concentration of the LL-gain animals was higher (P<0.05). The present results show that the reproductive performances of does subjected to the male effect in spring are poorer in those with a decreasing BW and BCS and better in those with increasing scores. This might be explained by the differences between groups in terms of their plasma insulin concentrations. The NEFA concentration was clearly modified by introduction to the males.


Subject(s)
Body Composition/physiology , Estrous Cycle/physiology , Goats/physiology , Weight Gain/physiology , Animals , Fatty Acids, Nonesterified/blood , Fatty Acids, Nonesterified/metabolism , Female , Male , Ovulation/physiology , Pregnancy
15.
Anim Reprod Sci ; 151(3-4): 157-63, 2014 Dec 30.
Article in English | MEDLINE | ID: mdl-25459077

ABSTRACT

The reproductive activity of 84 female Blanca Andaluza goats was monitored over 17 months to determine the role of body condition score (BCS) and body weight (BW) in its control. Following a 3×2 factorial experimental design, the animals were allocated to three groups: low BCS (≤2.50, n=24), medium BCS (BCS=2.75-3.00, n=31) and high BCS (≥3.25, n=29). The same animals, irrespective of the BCS group categorization, were also divided into two groups depending on BW: low BW (≤40kg, n=44) and high BW (>40kg, n=40). Oestrus was evaluated daily using vasectomised males. The ovulation rate was assessed by trans-rectal ultrasonography after the identification of oestrus. Ovulations were determined by monitoring the plasma progesterone concentration weekly. The BCS and BW were recorded once a week and nutritional status adjusted to maintain the initial differences in BW and BCS between the groups. Both BCS and BW had a significant (at least P<0.05) influence on the onset, the end, and the duration of the breeding season, with longer periods of reproductive activity recorded in does with a BCS of ≥2.75 and BW of >40kg. No significant interaction between these variables was observed. Some (11.7%) of the does in the groups with animals of BCS≥2.75 had ovulations during seasonal anoestrus. None of the does with a BCS of ≤2.5 had ovulations during seasonal anoestrus. The ovulation rate of the first and last oestrus was influenced by BW (P<0.01). These results demonstrate that Blanca Andaluza goats show marked reproductive seasonality that is clearly and independently modulated by BCS and BW.


Subject(s)
Body Constitution , Body Weight , Goats/physiology , Reproduction/physiology , Animals , Female , Male , Ovulation/physiology , Research Design , Seasons
16.
Theriogenology ; 82(9): 1310-5, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25266331

ABSTRACT

Goat does supposedly need to be separated from bucks before male stimuli can induce reproductive activity, ovulation, and estrous. The present study examined the reproductive response (ovulation and estrous) of does to "novel" bucks in direct contact with them and when separated from them by a fence. One hundred fourteen does were distributed into three groups: (1) ISOL group (N = 31): females that had been completely isolated from males for 46 days, and thereafter placed in direct contact with "novel" males during the breeding period; (2) NOTISOL-CONTACT group (N = 29): females that had been in contact with "familiar" vasectomized males for 46 days and thereafter placed in direct contact with novel males during the breeding period; (3) NOTISOL-NO CONTACT group (N = 54): females that were in contact with familiar vasectomized males for 46 days and thereafter introduced to novel males, but separated by a fence, during the breeding period. All the males were treated with melatonin to ensure that they were sexually active. Estrous activity was recorded daily by direct visual observation of the marks left by marking harnesses worn by the males. Ovulation was confirmed via the plasma progesterone concentration (measured in weekly blood samples). The ovulation rate was assessed by transrectal ultrasonography. Fecundity, fertility, prolificacy, and productivity were also determined for the ISOL and NOTISOL-CONTACT groups (naturally, in the NOTISOL-NO CONTACT group, no pregnancies were possible). The introduction of novel males induced the same ovarian response in each group (P > 0.05), but the percentage of females that showed estrous and ovulation was lower in the NOTISOL-NO CONTACT group (P < 0.05). No differences were seen between the ISOL and NOTISOL-CONTACT groups (P > 0.05) in terms of fecundity, fertility, prolificacy, and productivity. These results show that the introduction of novel males to females already in contact with familiar males induces ovarian activity similar to that observed in the classical male effect (ISOL group) and that this response leads to a significantly higher estrus activity only when direct physical contact between the females and the novel males is established.


Subject(s)
Goats/physiology , Sexual Behavior, Animal , Animals , Estrous Cycle , Female , Male , Ovulation , Progesterone/blood
17.
Anim Reprod Sci ; 146(3-4): 170-5, 2014 May.
Article in English | MEDLINE | ID: mdl-24631172

ABSTRACT

The aim of this study was to determine whether a seasonal pattern of reproductive events is followed after synchronisation by intravaginal progestagen sponge treatment in female Blanca Andaluza goats, and whether the timing of these events is affected by body condition score (BCS). During seasonal anoestrus (March), and again during the breeding season (November), the same 32 does were distributed into four subgroups according to their BCS: ≤2.25, =2.50, =2.75, and ≥3.00 (n=8 in all cases). They were then synchronised using a commercial intravaginal sponge treatment. Every 4h over the 72h following sponge removal, oestrous activity, the LH concentration and each doe's number of follicles were followed by transrectal ultrasonography. The does synchronised during seasonal anoestrus produced more follicles than those synchronised during the breeding season (P<0.01). The time elapsed between sponge removal and the onset of oestrus, the LH surge and time of ovulation, was also shorter in these does (P<0.001). The BCS only modified the number of follicles present in the ovary just before ovulation; this number was significantly lower in the =2.50 BCS subgroup than in the other subgroups (P<0.05). The present results show that the time to ovulation, and all events around it, are modified by the season in which Blanca Andaluza does are synchronised, but not by BCS.


Subject(s)
Estrus Synchronization/methods , Estrus/physiology , Goats/physiology , Luteinizing Hormone/metabolism , Ovulation/physiology , Progestins/pharmacology , Animals , Body Composition , Chorionic Gonadotropin/administration & dosage , Chorionic Gonadotropin/pharmacology , Drug Administration Routes , Estrus/drug effects , Female , Pregnancy , Progesterone/blood , Progestins/administration & dosage , Prostaglandins/administration & dosage , Prostaglandins/pharmacology , Seasons
18.
Rev. chil. nutr ; 41(1): 54-60, mar. 2014. ilus, tab
Article in Spanish | LILACS | ID: lil-710973

ABSTRACT

The aim of the study was to compare physical growth and body adiposity in Chilean adolescents according to the CDC -2000 and CDC-2012 reference. A numberof19,970students, between 14 and 18 years old, participated in the study. Adolescents belonged to the three units of the Chilean school education system. Weight, height and Body Mass Index were measured. The results indicated that Chilean students showed similar body weight, low height and high prevalence of overweight (28.3 to 32.5 %) according to the CDC-2000 reference. However, by the CDC- 2012 reference, results showed low weight and height, and consequently lower values of overweight (9.0 to 6.6%). We conclude that the use of a reference updates can cause confusion when analyzing the physical growth and body adiposity of Chilean adolescents. The results suggest the need for construction of a national curve which can be used to make the assessment of growth and nutritional status more reliably.


El objetivo del estudio fue comparar los parámetros del crecimiento físico y de adiposidad corporal en adolescentes chilenos en función a la referencia del CDC-2000 y CDC-2012. Se estudiaron 19970 escolares de 14 a 18 años. Los adolescentes pertenecen a las tres dependencias de escolaridad del sistema educativo chileno. Se determinó el peso, estatura y el Índice de Masa Corporal. Los resultados indicaron que los escolares chilenos mostraron similar peso corporal, menor estatura y altos valores de prevalencia de exceso de peso (28,3 a 32,5%) a través de la referencia del CDC-2000, sin embargo, por medio de la referencia del CDC-2012, mostraron bajo peso y estatura, consecuentemente valores inferiores de exceso de peso (9,0 a 6,6%). Se concluye que el uso de una referencia actualizada puede causar confusión al analizar el crecimiento físico y la adiposidad corporal de adolescentes chilenos. Los resultados sugieren la construcción de una curva nacional, con lo cual, es posible efectuar la valoración del crecimiento y estado nutricional de forma más confiable.


Subject(s)
Body Weights and Measures , Body Mass Index , Nutrition Assessment , Adolescent , Adiposity , Growth
19.
Nature ; 502(7473): 672-6, 2013 Oct 31.
Article in English | MEDLINE | ID: mdl-24172979

ABSTRACT

The biogeochemical cycles of carbon (C), nitrogen (N) and phosphorus (P) are interlinked by primary production, respiration and decomposition in terrestrial ecosystems. It has been suggested that the C, N and P cycles could become uncoupled under rapid climate change because of the different degrees of control exerted on the supply of these elements by biological and geochemical processes. Climatic controls on biogeochemical cycles are particularly relevant in arid, semi-arid and dry sub-humid ecosystems (drylands) because their biological activity is mainly driven by water availability. The increase in aridity predicted for the twenty-first century in many drylands worldwide may therefore threaten the balance between these cycles, differentially affecting the availability of essential nutrients. Here we evaluate how aridity affects the balance between C, N and P in soils collected from 224 dryland sites from all continents except Antarctica. We find a negative effect of aridity on the concentration of soil organic C and total N, but a positive effect on the concentration of inorganic P. Aridity is negatively related to plant cover, which may favour the dominance of physical processes such as rock weathering, a major source of P to ecosystems, over biological processes that provide more C and N, such as litter decomposition. Our findings suggest that any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P. These changes would uncouple the C, N and P cycles in drylands and could negatively affect the provision of key services provided by these ecosystems.


Subject(s)
Desert Climate , Desiccation , Ecosystem , Geography , Soil/chemistry , Aluminum Silicates/analysis , Biomass , Carbon/analysis , Carbon/metabolism , Carbon Cycle , Clay , Climate Change , Models, Theoretical , Nitrogen/analysis , Nitrogen/metabolism , Nitrogen Cycle , Phosphoric Monoester Hydrolases/analysis , Phosphoric Monoester Hydrolases/metabolism , Phosphorus/analysis , Phosphorus/metabolism , Plants/metabolism
20.
J Dent Res ; 92(11): 976-81, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24045646

ABSTRACT

Bone morphogenetic proteins (BMPs) are well-studied regulators of cartilage and bone development that have been Food and Drug Administration (FDA)-approved for the promotion of bone formation in certain procedures. BMPs are seeing more use in oral and maxillofacial surgeries because of recent FDA approval of InFUSE(®) for sinus augmentation and localized alveolar ridge augmentation. However, the utility of BMPs in medical and dental applications is limited by the delivery method. Currently, BMPs are delivered to the surgical site by the implantation of bulky collagen sponges. Here we evaluate the potential of detonation nanodiamonds (NDs) as a delivery vehicle for BMP-2 and basic fibroblast growth factor (bFGF). Nanodiamonds are biocompatible, 4- to 5-nm carbon nanoparticles that have previously been used to deliver a wide variety of molecules, including proteins and peptides. We find that both BMP-2 and bFGF are readily loaded onto NDs by physisorption, forming a stable colloidal solution, and are triggered to release in slightly acidic conditions. Simultaneous delivery of BMP-2 and bFGF by ND induces differentiation and proliferation in osteoblast progenitor cells. Overall, we find that NDs provide an effective injectable alternative for the delivery of BMP-2 and bFGF to promote bone formation.


Subject(s)
Bone Morphogenetic Protein 2/administration & dosage , Drug Delivery Systems , Fibroblast Growth Factor 2/administration & dosage , Nanodiamonds/chemistry , Osteogenesis/drug effects , Alkaline Phosphatase/analysis , Biocompatible Materials/chemistry , Cell Culture Techniques , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Colloids/chemistry , Diffusion , Humans , Myoblasts/drug effects , Osteoblasts/drug effects , Osteoblasts/physiology , Particle Size , Protein Binding , Spectroscopy, Fourier Transform Infrared , Stem Cells/drug effects , Stem Cells/physiology , Surface Properties
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