Growth Depression Research Articles

Larval size and metamorphosis are significantly reduced in second generation of inbred sea urchins Strongylocentrotus intermedius

Little experimental evidence of multiple generations of inbreeding depression is available for marine invertebrates. Here, we report that two generations of inbreeding significantly reduced larval growth and metamorphosis, but did not significantly impact fertilization and hatching in the sea urchin Strongylocentrotus intermedius. A higher inbreeding coefficient had significantly more negative impacts on some traits of S. intermedius larvae (for example, larval length) but not all. Maternal effects of inbreeding depression probably appear in the eight-arm stage and metamorphosis of S. intermedius. The present study provides convincing evidence of inbreeding depression on larval growth and metamorphosis in S. intermedius and highlights the importance of avoiding multiple generations of inbreeding in sea urchin aquaculture. Statement of relevanceMultiple inbreeding dramatically impacts aquaculture of marine species. Here, we investigated effects of second generation of inbreeding on fertilization, hatching, larval growth and metamorphosis in sea urchins. The present study provides the convincing evidence on the inbreeding depression of larval growth and metamorphosis in sea urchins and highlights the importance of avoiding multiple generation of inbreeding in sea urchin aquaculture.

Induced systemic listeriosis in Alectoris chukar chicks: clinical, histopathological and microbiological findings

1. Systemic listeriosis was induced in 14-d-old Chukar partridge chicks, Alectoris chukar, by intravenous injection of a suspension containing 106 cfu/ml of viable Listeria monocytogenes organisms to study the course of infection.2. Septicaemic and encephalitic forms of listeriosis were observed in all birds. Infection resulted in a fever response 8-h post-inoculation. Disease rapidly developed over a 24-h period with decreased activity, lethargy, ruffled feathers, huddling, listlessness, inability to stand, wing droop, decreased feed and water consumption, growth depression, neural disturbances and finally death. Gross and histopathological changes were observed in the myocardium, proventriculus, gizzard, intestine, pancreas, kidney, liver, spleen, lung, meninges and joints.3. The diversity of these clinical signs and lesions suggests a high susceptibility of Chukar partridge chicks to systemic listeriosis.

Individual non-essential amino acids fortification of a low-protein diet for broilers under the hot and humid tropical climate

A study was conducted to investigate the effects of feeding low-protein diets fortified with individual non-essential amino acids (NEAA) on growth performance, serum metabolites (uric acid, UA; triglycerides, TG; total protein, TP; and albumin, Alb), organ weight, breast yield, and abdominal fat weight in broiler chicks raised under the hot and humid tropical climate. Eight isocaloric (3,017 kcal/kg) experimental diets were formulated and fed to male broiler chicks from d 1–21 as follows: 1) 22.2% crude protein (CP) (positive control; PC); 2) 16.2% CP + mixture essential amino acids (EAA) to meet or exceed the National Research Council (1994) recommendations (negative control; NC); 3) NC + glycine (Gly) to equal the total glycine + serine level in the PC; diets 4 through 7 were obtained by supplementing NC diet with individual glutamic acid, proline, alanine, or aspartic acid (Glu, Pro, Ala, or Asp, respectively); 8) NC + NEAA (Gly + Glu + Pro + Ala + Asp) to equal the total level of these NEAA in the PC. Fortifying NC diet with mixture NEAA resulted in a similar growth performance as PC. However, fortification of low-CP diet with individual NEAA failed to improve body weight (BW) (P < 0.0001), feed intake (FI) (P = 0.0001), and feed conversion ratio (FCR) (P = 0.0001). Serum uric acid (UA) was lower (P = 0.0356) in NC birds and NC diet supplemented with individual NEAA birds, whereas serum triglyceride (TG) (P = 0.007) and relative weight of abdominal fat (P = 0.001) were higher in these birds. In conclusion, no single NEAA fortification may compensate the depressed growth performance attributed to a low-CP diet. However, fortification with Gly may improve FCR. There is a possibility that broilers raised under the hot and humid climate require higher Gly fortification than the level used in this study.

Bayesian Modeling of Prion Disease Dynamics in Mule Deer Using Population Monitoring and Capture-Recapture Data.

Epidemics of chronic wasting disease (CWD) of North American Cervidae have potential to harm ecosystems and economies. We studied a migratory population of mule deer (Odocoileus hemionus) affected by CWD for at least three decades using a Bayesian framework to integrate matrix population and disease models with long-term monitoring data and detailed process-level studies. We hypothesized CWD prevalence would be stable or increase between two observation periods during the late 1990s and after 2010, with higher CWD prevalence making deer population decline more likely. The weight of evidence suggested a reduction in the CWD outbreak over time, perhaps in response to intervening harvest-mediated population reductions. Disease effects on deer population growth under current conditions were subtle with a 72% chance that CWD depressed population growth. With CWD, we forecasted a growth rate near one and largely stable deer population. Disease effects appear to be moderated by timing of infection, prolonged disease course, and locally variable infection. Long-term outcomes will depend heavily on whether current conditions hold and high prevalence remains a localized phenomenon.

Effect of targeted ovarian cancer immunotherapy using ovarian cancer stem cell vaccine.

BackgroundAccumulating evidence has shown that different immunotherapies for ovarian cancer might overcome barriers to resistance to standard chemotherapy. The vaccine immunotherapy may be a useful one addition to conditional chemotherapy regimens. The present study investigated the use of vaccine of ovarian cancer stem cells (CSCs) to inhibit ovarian cancer growth.MethodsCD117+CD44+CSCs were isolated from human epithelial ovarian cancer (EOC) SKOV3 cell line by using a magnetic-activated cell sorting system. Pre-inactivated CD117+CD44+CSC vaccine was vacccinated into athymic nude mice three times, and then the mice were challenged subcutaneously with SKOV3 cells. The anti-tumor efficacy of CSC vaccine was envaluated by in vivo tumorigenicity, immune efficient analysis by flow cytometer, and enzyme-linked immunosorbent assays, respectively.ResultsThe CD117+ CD44+CSC vaccine increased anti-ovarian cancer efficacy in that it depressed ovarian cancer growth in the athymic nude mice. Vaccination resulted in enhanced serum IFN-γ, decreased TGF-β levels, and increased cytotoxic activity of natural killer cells in the CD117+ CD44+CSC vaccine immunized mice. Moreover, the CSC-based vaccine significantly reduced the CD117+CD44+CSC as well as the aldehyde dehydrogenase 1 positive cell populations in the ovarian cancer tissues in the xenograft mice.ConclusionThe present study provided the first evidence that human SKOV3 CD117+ CD44+CSC-based vaccine may induce the anti-ovarian cancer immunity against tumor growth by reducing the CD117+CD44+CSC population.

Isolation and molecular characterization of newly emerging avian reovirus variants and novel strains in Pennsylvania, USA, 2011-2014.

Avian reovirus (ARV) infections of broiler and turkey flocks have caused significant clinical disease and economic losses in Pennsylvania (PA) since 2011. Most of the ARV-infected birds suffered from severe arthritis, tenosynovitis, pericarditis and depressed growth or runting-stunting syndrome (RSS). A high morbidity (up to 20% to 40%) was observed in ARV-affected flocks, and the flock mortality was occasionally as high as 10%. ARV infections in turkeys were diagnosed for the first time in PA in 2011. From 2011 to 2014, a total of 301 ARV isolations were made from affected PA poultry. The molecular characterization of the Sigma C gene of 114 field isolates, representing most ARV outbreaks, revealed that only 21.93% of the 114 sequenced ARV isolates were in the same genotyping cluster (cluster 1) as the ARV vaccine strains (S1133, 1733, and 2048), whereas 78.07% of the sequenced isolates were in genotyping clusters 2, 3, 4, 5, and 6 (which were distinct from the vaccine strains) and represented newly emerging ARV variants. In particular, genotyping cluster 6 was a new ARV genotype that was identified for the first time in 10 novel PA ARV variants of field isolates.

Production of Bio-omega-3 eggs through the supplementation of extruded flaxseed meal in hen diet.

BackgroundThe full-fat flaxseed meal has obtained relatively new flourished concept as staple chicken feedstuff for the production of designer eggs. However, unprocessed flaxseed also encloses well documented anti-nutritional factors which are associated with growth depression of laying hens. The present research work was carried out to evaluate the impact of full-fat extruded flaxseed meal supplemented diets on productivity performance of hens and production of modified ω-3 fatty acids-enriched eggs.MethodsThe full-fat flaxseed meal was extruded at barrel exit temperature (140 °C), screw speed (160 rpm) and feed rate (25 kg/h) for reduction of anti-nutritional compounds. One hundred and sixty, Babcock hens (age 24 weeks old) were selected at random from a large flock and ten hens were placed in each of 16 wire-mesh pens. The experimental diets prepared by supplementation of extruded flaxseed at 10 %, 20 % and 30 % level were fed to hens along with control.ResultsThe extruded flaxseed contained 86 % and 76 % less hydrocyanic compounds and tannin, respectively than the initial material. The hens fed with control diet consumed more feed, possessed heavy body weight and showed higher egg production as compared to hens fed on extruded flaxseed supplemented diets. The loss in body weight and egg production was recorded less for hens fed on 10 % extruded flaxseed supplemented diets as compared to those fed on 30 % extruded flaxseed supplemented diets. None of the experimental diets resulted in significant increase or decrease the total lipids and cholesterol content in egg yolk of hens. The extruded flaxseed supplemented diets resulted in a significant improvement of α-linolenic and docosahexaenoic acid in egg yolk with a concomitant reduction in arachidonic acid. The sensory scores were assigned higher to control eggs. Increasing level of extruded flaxseed in experimental diets decreased the scores for all sensory attributes of eggs.ConclusionThe present study suggested that extruded flaxseed meal up to 20 % can be supplemented in the diets of hens for maximum deposition of α-linolenic acid and docosahexaenoic acid in egg yolk with acceptable detrimental effects on egg traits.

MTOR in Brain Physiology and Pathologies

TOR (target of rapamycin) and its mammalian ortholog mTOR have been discovered in an effort to understand the mechanisms of action of the immunosuppressant drug rapamycin extracted from a bacterium of the Easter Island (Rapa Nui) soil. mTOR is a serine/threonine kinase found in two functionally distinct complexes, mTORC1 and mTORC2, which are differentially regulated by a great number of nutrients such as glucose and amino acids, energy (oxygen and ATP/AMP content), growth factors, hormones, and neurotransmitters. mTOR controls many basic cellular functions such as protein synthesis, energy metabolism, cell size, lipid metabolism, autophagy, mitochondria, and lysosome biogenesis. In addition, mTOR-controlled signaling pathways regulate many integrated physiological functions of the nervous system including neuronal development, synaptic plasticity, memory storage, and cognition. Thus it is not surprising that deregulation of mTOR signaling is associated with many neurological and psychiatric disorders. Preclinical and preliminary clinical studies indicate that inhibition of mTORC1 can be beneficial for some pathological conditions such as epilepsy, cognitive impairment, and brain tumors, whereas stimulation of mTORC1 (direct or indirect) can be beneficial for other pathologies such as depression or axonal growth and regeneration.

Compensatory Growth in Juveniles of Freshwater Redclaw Crayfish Cherax quadricarinatus Reared at Three Different Temperatures: Hyperphagia and Food Efficiency as Primary Mechanisms

Feeding restriction, as a trigger for compensatory growth, might be considered an alternative viable strategy for minimizing waste as well as production costs. The study assessed whether juvenile redclaw crayfish Cherax quadricarinatus (initial weight 0.99 ±0.03 g) was able to compensate for feeding restriction at different temperatures (23±1, 27±1 and 31±1°C). Hyperphagia, food utilization efficiency, energetic reserves, and hepatopancreas structure were analyzed. Three temperatures and two feeding regimes (DF-daily fed throughout the experiment and CF- 4 days food deprivation followed by 4 days of feeding, intermittently) were tested. The restriction period was from day 1 to 45, and the recovery period was from day 45 to 90. The previously restricted crayfish held at 23, 27, and 31 ± 1°C displayed complete body weight catch-up through compensatory growth following the restriction period with depressed growth. The mechanisms that might explain this response were higher feed intake (hyperphagia), and increased food utilization efficiency. Hepatopancreatic lipids were used as a metabolic fuel and hepatosomatic index was reduced in the previously restricted crayfish, but recovery at the same level of unrestricted crayfish occurred after the shift to daily feeding. The highest temperature affected adversely growth, feed intake, food efficiency, and metabolism of crayfish, whereas the lowest temperature and feeding restriction induced a more efficient growth of the crayfish.

Atrazine triggers developmental abnormality of ovary and oviduct in quails (Coturnix Coturnix coturnix) via disruption of hypothalamo-pituitary-ovarian axis

There has been a gradual increase in production and consumption of atrazine (ATR) in agriculture to meet the population rising demands. Female reproduction is necessary for growth and maintenance of population. However, ATR impact on females and particularly ovarian developmental toxicity is less clear. The aim of this study was to define the pathways by which ATR exerted toxic effects on ovarian development of ovary and hypothalamo-pituitary-ovarian (HPO) axis. Female quails were dosed by oral gavage from sexual immaturity to maturity with 0, 50, 250 and 500 mg ATR/kg/d for 45 days. ATR had no effect on mortality but depressed feed intake and growth and influenced the biochemical parameters. Notably, the arrested development of ovaries and oviducts were observed in ATR-exposed quails. The circulating concentrations of E2, P, LH and PRL were unregulated and FSH and T was downregulated in ATR-treated quails. The mRNA expression of GnRH in hypothalamo and LH in pituitary and FSH in ovary was downregulated significantly by ATR exposure and FSH and PRL in pituitary were upregulated. ATR exposure upregulated the level of P450scc, P450arom, 3β-HSD and 17β-HSD in ovary and downregulated ERβ expression in female quails. However, ATR did not change ERα expression in ovary. This study provides new insights regarding female productive toxicology of ATR exposure. Ovary and oviduct in sexually maturing females were target organs of ATR-induced developmental toxicity. We propose that ATR-induced developmental abnormality of ovary and oviduct is associated with disruption of gonadal hormone balance and HPO axis in female quails.

Soyabean glycinin depresses intestinal growth and function in juvenile Jian carp (Cyprinus carpio var Jian): protective effects of glutamine.

This study investigated the effects of glycinin on the growth, intestinal oxidative status, tight junction components, cytokines and apoptosis signalling factors of fish. The results showed that an 80 g/kg diet of glycinin exposure for 42 d caused poor growth performance and depressed intestinal growth and function of juvenile Jian carp (Cyprinus carpio var. Jian). Meanwhile, dietary glycinin exposure induced increases in lipid peroxidation and protein oxidation; it caused reductions in superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) activities; and it increased MnSOD, CuZnSOD, GPx1b and GPx4a mRNA levels, suggesting an adaptive mechanism against stress in the intestines of fish. However, dietary glycinin exposure decreased both the activity and mRNA levels of nine isoforms of glutathione-S-transferase (GST) (α, μ, π, ρ, θ, κ, mGST1, mGST2 and mGST3), indicating toxicity to this enzyme activity and corresponding isoform gene expressions. In addition, glycinin exposure caused partial disruption of intestinal cell-cell tight junction components, disturbances of cytokines and induced apoptosis signalling in the distal intestines>mid intestines>proximal intestines of fish. Glycinin exposure also disturbed the mRNA levels of intestinal-related signalling factors Nrf2, Keap1a, Keap1b, eleven isoforms of protein kinase C and target of rapamycin/4E-BP. Interestingly, glutamine was observed to partially block those negative influences. In conclusion, this study indicates that dietary glycinin exposure causes intestinal oxidative damage and disruption of intestinal physical barriers and functions and reduces fish growth, but glutamine can reverse those negative effects in fish. This study provides some information on the mechanism of glycinin-induced negative effects.

INFLUENCE OF MYCORRHIZAS, ORGANIC SUBSTRATES AND CONTAINER VOLUMES ON THE GROWTH OF Heliocarpus popayanensis Kunth

ABSTRACT This work assessed, under nursery conditions, the effect of arbuscular mycorrhizal fungi (AMF) inoculation on the initial growth of the woody species Heliocarpus popayanensis Kunth in containers of different sizes (nursery tubes of 50 or 250 cm3) containing composted cattle manure or organic Pinus spp bark compost diluted (0 to 100%, each 9%) with low fertility soil. Plants in cattle manure grew more than plants grown in pine bark manure independent of tube size. AMF were more efficient in improving plant growth in 250 cm3 tubes than in 50 cm3 tubes independent of the substrates. Mycorrhizal plants grown in 50 cm3 tubes showed less growth than non-mycorrhizal ones irrespective of the substrates. Nevertheless, this growth depression decreased with an increase of substrates dilution with low fertility soil. In the higher dilutions, growth depression did not occur and there was a positive response to AMF inoculation. In addition, only mycorrhizal plantlets showed some growth in low fertility soil as the sole substrate. These results indicated that AMF affect plantlet growth positively or negatively depending on the combination of substrates, fertility level, and container size.

Biochar increases arbuscular mycorrhizal plant growth enhancement and ameliorates salinity stress

We examined combined effects of biochar, arbuscular mycorrhizal (AM) fungi and salinity on plant growth and physiology to test whether and how biochar influences AM fungi mediated growth and nutrition enhancements, and whether and how biochar provides amelioration in salt stressed soils. We carried out a full three-factorial greenhouse experiment with Lactuca sativa; and a second study with a wider range of biochar and salt additions to examine physicochemical effects on soil parameters. Biochar together with AM fungal inoculation resulted in an additional plant yield increase compared to each alone under non-saline conditions. In parallel with increased plant growth, we found increased uptake of P and Mn with AM fungi and biochar addition, but to a lesser extent than biochar-induced growth promotion. Both factors, but especially biochar alleviated salinity-caused growth depressions, and improved Na/K ratio in salinity stressed plants. Reduced Na uptake of plants and reduced conductivity in biochar-ameliorated soils suggest that a likely mechanism involves ion adsorption to biochar surfaces. Our results suggest that plants depend on symbiotic microorganisms to fully exploit biochar benefits in soils, suggesting avenues for joint management in agriculture. Biochar may be advantageous in saline soils, but long-term studies are required before recommendations should be given.

Integrating a Parenting Intervention With Routine Primary Health Care: A Cluster Randomized Trial.

More than 200 million children globally do not attain their developmental potential. We hypothesized that a parent training program could be integrated into primary health center visits and benefit child development. We conducted a cluster randomized trial in the Caribbean (Jamaica, Antigua, and St Lucia). Fifteen centers were randomly assigned to the control (n = 250 mother-child pairs) and 14 to the intervention (n = 251 mother-child pairs) groups. Participants were recruited at the 6- to 8-week child health visit. The intervention used group delivery at 5 routine visits from age 3 to 18 months and comprised short films of child development messages, which were shown in the waiting area; discussion and demonstration led by community health workers; and mothers' practice of activities. Nurses distributed message cards and a few play materials. Primary outcomes were child cognition, language, and hand-eye coordination and secondary outcomes were caregiver knowledge, practices, maternal depression, and child growth, measured after the 18-month visit. Eight-five percent of enrolled children were tested (control = 210, intervention = 216). Loss did not differ by group. Multilevel analyses showed significant benefits for cognitive development (3.09 points; 95% confidence interval: 1.31 to 4.87 points; effect size: 0.3 SDs). There were no other child benefits. There was a significant benefit to parenting knowledge (treatment effect: 1.59; 95% confidence interval: 1.01 to 2.17; effect size: 0.4). An innovative parenting intervention, requiring no additional clinic staff or mothers' time, was integrated into health services, with benefits to child cognitive development and parent knowledge. This is a promising strategy that merits further evaluation at scale.

Prophylaxis of post-weaning diarrhoea in piglets by zinc oxide and sodium humate

The high prophylactic doses of ZnO commonly used to control post-weaning diarrhoea (PWD) in piglets have become an environmental problem. The possibility of partial replacement of ZnO by sodium humate (HNa) in PWD treatment was investigated in this study. Weaned piglets (32) were challenged with two enterotoxigenic E. coli strains (ETEC/O149/F4/LT and ETEC/O147/F18/LT) and allocated into four treatments maintained for three weeks: C (no supplementation); ZnO2.5 (2.5 g ZnO/kg diet); HNa + ZnO1.0; HNa + ZnO1.5; HNa + ZnO1.7 (20 g HNa and 1.0, 1.5 and 1.7 g ZnO/kg diet, respectively). The effects on incidence, severity and duration of diarrhoea, faecal shedding of total E. coli and both ETEC strains, growth rate and selected blood parameters were investigated. In contrast with ZnO2.5 and HNa + ZnO1.7, high daily diarrhoea scores, incidence and duration and mortality due to severe dehydration were seen in C, HNa + ZnO1.0 and HNa + ZnO1.5 groups. The administration of ZnO and HNa did not affect the faecal shedding of the challenged ETEC strains for eght days, even in clinically healthy piglets in ZnO2.5 and HNa + ZnO1.7 groups. Signs of growth depression were found in C; HNa + ZnO1.0 and HNa + ZnO1.5 groups during the first week. No difference in growth performance was observed in ZnO2.5 and HNa + ZnO1.7 piglets. Most of the selected biochemical and haematological parameters did not differ significantly among the treatments. However, a significantly higher serum Zn as a result of high dietary ZnO intake in the ZnO2.5 group compared to the control and HNa groups was detected. Significantly lower serum P in ZnO2.5; HNa + ZnO1.7 and HNa + ZnO1.0 groups compared to the control group was most likely induced by the increased Zn in serum. The results indicate the possibility of reducing the high pharmacological levels of ZnO in the prophylaxis of PWD through partial replacement with HNa. Such a treatment maintains the favourable prophylactic effect while lowering the Zn content in faeces.

Effects of riboflavin supplementation on growth performance, carcass traits, and riboflavin status of growing male white Pekin ducks

An experiment involving six dietary riboflavin concentration (1.38, 2.38, 3.38, 4.38, 5.38, and 6.38mg/kg) was conducted to determine the effects of riboflavin on performance and riboflavin status of growing male white Pekin ducks in terms of growth performance, carcass traits, and free riboflavin, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) concentration in the liver and plasma. A basal corn-soybean meal containing 1.38mg/kg of naturally occurring riboflavin was used and this basal diet was fed with 0, 1, 2, 3, 4, and 5mg/kg diet of supplemental riboflavin. One-day-old male white Pekin ducks were fed common starter diets from hatch to 14 days of age and then fed the experimental diets from 15 to 35 days of age. A total of 288 15-day-old ducks were allotted to 6 dietary treatments with 6 replicate pens of 8 birds per pen. At 35 days of age, the average daily weight gain (ADG), average daily feed intake (ADFI), gain to feed ratio (G:F), and percentage yield of breast and leg meat, abdominal fat were examined and free riboflavin, FMN, and FAD in plasma or liver were all analyzed. The growth depression, low plasma free riboflavin, liver free riboflavin, liver FMN, and liver FAD concentration were observed in the ducks fed the riboflavin-deficient basal diet (P<0.05), and these adverse effects were alleviated by riboflavin supplementation. The growing ducks fed the basal diet with no supplementation of riboflavin had the lowest ADG, ADFI, G:F and breast meat yield among all ducks (P<0.05) and these criteria showed linear or quadratic response to increasing dietary riboflavin (P<0.05). On the other hand, dietary riboflavin influenced the status of this vitamin in growing ducks. The poorest growth performance of the riboflavin-deficient growing ducks was accompanied with the lowest content of riboflavin, FAD, and FMN in plasma or liver (P<0.05) but these bad statuses were reversed by increasing dietary riboflavin in which the riboflavin and its derivative increased linearly or quadratically as dietary riboflavin increased (P<0.05). According to the broken-line model, the riboflavin requirements (based on dietary total riboflavin) of male white Pekin ducks from 15 to 35 days of age for ADG, ADFI, G:F, plasma free riboflavin, liver free riboflavin, and liver FMN were 2.43, 2.48, 2.31, 3.57, 2.78, and 2.83mg/kg, respectively.

Longitudinal investigation of anxiety sensitivity growth trajectories and relations with anxiety and depression symptoms in adolescence.

Anxiety sensitivity (AS), the belief that anxious arousal is harmful, is a malleable risk factor that has been implicated in anxiety and depression symptoms in adolescents. Although there is some evidence that adolescents possess distinct developmental trajectories, few studies have explored this topic. This study examined the developmental trajectory of AS in 248 adolescents (M age = 11.0 years, SD = 0.82; 56% male) across 6 years, beginning when children were age 11. This study also examined the influence of AS trajectories on anxiety and depression at age 16. Finally, this study examined the utility of AS classes in identifying anxiety and depression growth. Three AS classes were found, described by normative-stable, high-stable, and high-unstable trajectories. Adolescents in the high-stable and the high-unstable AS classes had higher levels of anxiety and depression at age 16 than did adolescents in the normative-stable AS class. In addition, the anxiety and depression trajectories fit by AS class mirrored the AS class trajectories. These findings suggest three AS trajectories can be identified in adolescents. These trajectories are discussed in relation to a developmental perspective of AS.

Nitric oxide can induce tolerance to oxidative stress of peanut seedlings under cadmium toxicity

To study the role of sodium nitroprusside (SNP, a donor of NO) in alleviating cadmium (Cd) toxicity in peanut (Arachis hypogaea L.), peanut seedlings exposed to 50, 100, or 200 µM Cd as CdCl2 were treated with 250 µM SNP. Cd exposure depressed plant growth, inhibited the photosynthesis, and resulted in oxidative stress. In roots, Cd was mostly trapped in the cell wall under low Cd stress, but most Cd was accumulated in the soluble fraction under high Cd concentrations. In leaves, a majority of Cd was accumulated in the cell wall regardless of Cd treatment level. Addition of SNP at 250 µM significantly alleviated Cd toxicity in peanut seedlings, including improved photosynthesis, up-regulated antioxidant system, and reduced Cd translocation from roots to shoots as evidenced by decreased Cd accumulation in stems and leaves. SNP application also changed the subcellular distribution of Cd in leaf and root tissues, by increasing Cd retention in root and leaf cell wall while reducing Cd accumulation in the soluble fractions and cell organelles. These results indicate that SNP has great application potential for improving the growth of plants under heavy metal stress such as Cd toxicity.

Weaning age affects growth, feed intake, gastrointestinal development, and behavior in Holstein calves fed an elevated plane of nutrition during the preweaning stage

Recent research has revealed potential advantages of feeding an elevated plane of nutrition to calves during the preweaning period. However, calves fed more nutrients preweaning may be more susceptible to depressed growth and weaning stress during the transition from liquid to solid feed. The objective of this study was to investigate the relationship between the age of weaning and feed intake, and its influence on growth, gastrointestinal development, and behavioral indicators in dairy calves fed an elevated plane of nutrition during the preweaning period. To meet this objective, 20 female Holstein calves were randomly assigned at birth to be weaned at 6 or 8 wk. Milk replacer (mixed at 150 g/L) was offered at 1.2 kg/calf per day in 2 meals until a 1-wk step-down, when meals were reduced by 50% 1 wk before weaning. Daily starter, chopped oat straw, water intake, and weekly body weights were measured until d 70 of life. To assess digestive tract development, rumen fluid, fecal, and blood samples were taken before and after weaning (d 35, 49, and 63) and analyzed for ruminal short-chain fatty acids, blood β-hydroxybutyrate, and fecal starch, respectively. Behavioral indicators of weaning stress, including vocalizing and non-nutritive oral behavior, were measured by visual observation for 1 h, 3 times per week, before the second feeding of the day during the period from 2 wk before weaning to 2 wk after weaning. The calves weaned at 8 wk compared with 6 wk had higher average daily gain for the week preweaning (0.79±0.09 vs. 0.34±0.10 kg/d) and postweaning (1.05±0.09 vs. 0.35±0.11 kg/d), and were heavier at d 70 (99.9±1.81 vs. 91.0±2.26 kg). From 5 to 8 wk of age, starter and water intakes were lower in calves weaned at 8 wk of age. However, overall starter intake did not differ during the last week of the experiment. Furthermore, calves weaned at 8 wk compared with 6 wk had higher starter intake for 1 wk preweaning (1.36±0.13 vs. 0.40±0.08 kg/d) and postweaning (2.51±0.20 vs. 1.16±0.15 kg/d). In both treatments, weaning increased ruminal short-chain fatty acids, blood β-hydroxybutyrate, and fecal starch, yet the differences between the week before and after weaning were greater for calves weaned at 6 wk compared with those weaned at 8 wk. Treatment × week relative to weaning interactions indicated that several behaviors varied between early- and later-weaned calves during the week before weaning; calves weaned at 6 wk tended to exhibit 75% more non-nutritive oral behavior and spent 55% less time ruminating, and 36% less time lying compared with calves weaned at 8 wk. Under the conditions of this study, the results suggest that calves fed an elevated plane of nutrition preweaning have higher starter intakes and average daily gain during the weaning period when weaning is extended from 6 to 8 wk of age.

Coral growth patterns of Montastraea cavernosa and Porites astreoides in the Florida Keys: The importance of thermal stress and inimical waters

The calcification and extension rates of two species of scleractinian coral (Montastraea cavernosa, Porites astreoides) were measured in corals experimentally transplanted to paired inshore and offshore locations in the Upper, Middle, and Lower Florida Keys from 2010 to 2011. Growth rates were compared with respect to 1) shelf location, 2) species, 3) region, and 4) temperature. Transplanted corals on inshore reefs generally calcified less than those at paired offshore sites, but these differences were only significant in a few cases. This difference in growth is likely because of two thermal stress events that occurred inshore, but not offshore, as growth records from cores of P. astreoides revealed significantly higher extension and calcification inshore from 2001–2013. The core data confirmed that the years 2010–2012 were a period of depressed growth inshore. Calcification and extension rates of the experimental corals were not statistically different between M. cavernosa and P. astreoides within a given site. The only exceptions were that calcification was higher in M. cavernosa at the Middle Keys inshore site. The Middle Florida Keys sites had the lowest rates of calcification, supporting the hypothesis that the influence of Florida Bay waters in this region contributes to poor reef development. Mean calcification rates negatively correlated with metrics of cold stress in M. cavernosa and heat stress in P. astreoides. The lack of a significant correlation between heat stress and mean calcification in M. cavernosa may help explain this species persistence on today's reefs. Maximum calcification and mean extension, however, were negatively correlated with maximum running 30-day mean temperature, showing that the growth of M. cavernosa is not completely insensitive to warm water stress. The ‘weedy’ life-history strategy of P. astreoides may compensate for the sensitivity of calcification rates to heat stress reported here, allowing this species to maintain the stable populations that have been observed throughout Florida and the wider Caribbean.