Depolymerization of aryltellurinic anhydrides with sodium hydroxide. Synthesis and structure of the hydrated sodium aryltellurinates [Na(H2O)4](RTeO2) (R = 4-MeOC6H4, 8-Me2NC10H6)

Depolymerization of the aryltellurinic anhydrides [(RTe)₂O₃]_n (9, R = 4-MeOC₆H₄; 6, R = 8-Me₂NC₁₀H₆) with aqueous NaOH afforded the hydrated sodium aryltellurinates [Na(H₂O)₄](4-MeOC₆H₄TeO₂) (10) and [Na(H₂O)₄](8-Me₂NC₁₀H₆TeO₂)·H₂O (11·H₂O) as highly crystalline materials.

Dietary salt intake assessed by 24 h urinary sodium excretion in Australian schoolchildren aged 5–13 years

Objective To measure total daily salt intake using 24 h urinary Na excretion within a sample of Victorian schoolchildren aged 5–13 years and to assess discretionary salt use habits of children and parents.

Design Cross-sectional study.

Setting Completed within a convenience sample of independent primary schools (n 9) located in Victoria, Australia.

Subjects Two hundred and sixty children completed a 24 h urine collection over a school (34 %) or non-school day (66 %). Samples deemed incomplete (n 18), an over-collection (n 1) or that were incorrectly processed at the laboratory (n 3) were excluded.

Results The sample comprised 120 boys and 118 girls with a mean age of 9·8 (sd 1·7) years. The average 24 h urinary Na excretion (n 238) was 103 (sd 43) mmol/24 h (salt equivalent 6·0 (sd 2·5) g/d). Daily Na excretion did not differ by sex; boys 105 (sd 46) mmol/24 h (salt equivalent 6·1 (sd 2·7) g/d) and girls 100 (sd 41) mmol/24 h (salt equivalent 5·9 (sd 2·4) g/d; P = 0·38). Sixty-nine per cent of children (n 164) exceeded the recommended daily Upper Limit for Na. Reported discretionary salt use was common: two-thirds of parents reported adding salt during cooking and almost half of children reported adding salt at the table.

Conclusions The majority of children had salt intakes exceeding the recommended daily Upper Limit. Strategies to lower salt intake in children are urgently required, and should include product reformulation of lower-sodium food products combined with interventions targeting discretionary salt use within the home.

Over-winter lipid depletion and mortality of age-0 rainbow trout (Oncorhynchus mykiss)

In this study we identify the size-dependent risk of winter starvation mortality as a strong selective pressure on age-0 rainbow trout (Oncorhynchus mykiss) that could promote the risk-taking behaviour and allocation of energy to lipids previously observed in young trout cohorts. Age-0 trout subjected to simulated winter starvation conditions gradually depleted lipid reserves to a critical minimum lipid content below which death occurred. Small fish with lower lipid content exhausted lipid reserves earlier, and experienced high mortality rates sooner, than larger fish with greater lipid content. Consequently, winter starvation endurance was dependent upon size-dependent lipid reserves and winter duration. To validate the laboratory findings in the field, we stocked several size classes of hatchery-raised trout with known lipid content at the start of winter into two experimental lakes, and estimated survival and lipid depletion at winter's end. Larger age-0 trout had greater initial lipid reserves than smaller trout. Individuals depleted most of their lipid reserves over the winter, and experienced mortality that ranged from just under 60% for the largest individuals to just over 90% of the smallest individuals. Many survivors had lipid contents near, but none were below, the minimum lipid content determined in the laboratory.

Rapid depletion of genotypes with fast growth and bold personality traits from harvested fish populations

The possibility for fishery-induced evolution of life history traits is an important but unresolved issue for exploited fish populations. Because fisheries tend to select and remove the largest individuals, there is the evolutionary potential for lasting effects on fish production and productivity. Size selection represents an indirect mechanism of selection against rapid growth rate, because individual fish may be large because of rapid growth or because of slow growth but old age. The possibility for direct selection on growth rate, whereby fast-growing genotypes are more vulnerable to fishing irrespective of their size, is unexplored. In this scenario, faster-growing genotypes may be more vulnerable to fishing because of greater appetite and correspondingly greater feeding-related activity rates and boldness that could increase encounter with fishing gear and vulnerability to it. In a realistic whole-lake experiment, we show that fast-growing fish genotypes are harvested at three times the rate of the slow-growing genotypes within two replicate lake populations. Overall, 50% of fast-growing individuals were harvested compared with 30% of slow-growing individuals, independent of body size. Greater harvest of fast-growing genotypes was attributable to their greater behavioral vulnerability, being more active and bold. Given that growth is heritable in fishes, we speculate that evolution of slower growth rates attributable to behavioral vulnerability may be widespread in harvested fish populations. Our results indicate that commonly used minimum size-limits will not prevent overexploitation of fast-growing genotypes and individuals because of size-independent growth-rate selection by fishing.

Effect of sodium selenite-enriched reperfusion solutions on rat cardiac ischemia reperfusion injury

Cardiac surgery often generates oxidative stress leading to ischemia reperfusion injury (I-R). Antioxidants have been shown to prevent this injury and have been added to cardioplegic solutions to assist in recovery. In this study, we tested the effectiveness of sodium selenite in protecting against ischemia reperfusion injury and investigated the mechanisms behind this protection. Hearts from male Wistar rats were subjected to ischemia reperfusion using the Langendorf model. Krebs-Henseleit perfusion solutions were supplemented with 0,0.1, 0.5, 1.0, and 10μM sodium selenite. Hearts were perfused for 30 min and then subjected to 22.5 min of global ischemia followed by 45 min reperfusion. Heart rate, ischemic contracture, end diastolic pressure, and developed ventricular pressure were monitored. At the completion of the experiment, hearts were homogenized and tissue extracts were assayed for glutathione peroxidase (GSH-Px) and thioredoxin reductase (Thx-Red) activity. Sodium selenite, at a concentration of 0.5 μM, demonstrated a protective effect on the recovery of cardiac function following I-R, as evidenced by a lower end diastolic pressure and enhanced recovery of rate pressure product. There was no beneficial effect observed in hearts perfused with 0.1 μM sodium selenite-supplemented buffer, whereas poorer functional recovery was observed in hearts perfused with 10 μM sodium selenite-supplemented buffer. The beneficial effect of sodium selenite was not mediated through increased activity of GSH-Px or Thx-Red. This study demonstrates that the addition of sodium selenite to reperfusion solutions, at an optimal concentration of 0.5 μM, assists in cardiac recovery following ischemia reperfusion.

Is socioeconomic status associated with dietary sodium intake in Australian children? A cross-sectional study

Objective To assess the association between socioeconomic status (SES) and dietary sodium intake, and to identify if the major dietary sources of sodium differ by socioeconomic group in a nationally representative sample of Australian children.

Design Cross-sectional survey.

Setting 2007 Australian National Children's Nutrition and Physical Activity Survey.

Participants A total of 4487 children aged 2–16 years completed all components of the survey.

Primary and secondary outcome measures Sodium intake was determined via one 24 h dietary recall. The population proportion formula was used to identify the major sources of dietary salt. SES was defined by the level of education attained by the primary carer. In addition, parental income was used as a secondary indicator of SES.

Results Dietary sodium intake of children of low SES background was 2576 (SEM 42) mg/day (salt equivalent 6.6 (0.1) g/day), which was greater than that of children of high SES background 2370 (35) mg/day (salt 6.1 (0.1) g/day; p<0.001). After adjustment for age, gender, energy intake and body mass index, low SES children consumed 195 mg/day (salt 0.5 g/day) more sodium than high SES children (p<0.001). Low SES children had a greater intake of sodium from processed meat, gravies/sauces, pastries, breakfast cereals, potatoes and potato snacks (all p<0.05).

Conclusions Australian children from a low SES background have on average a 9% greater intake of sodium from food sources compared with those from a high SES background. Understanding the socioeconomic patterning of salt intake during childhood should be considered in interventions to reduce cardiovascular disease.

Dietary sodium intake is associated with total fluid and sugar-sweetened beverage consumption in US children and adolescents aged 2 - 18 y : NHANES 2005 - 2008

Background: Increasing dietary sodium drives the thirst response. Because sugar-sweetened beverages (SSBs) are frequently consumed by children, sodium intake may drive greater consumption of SSBs and contribute to obesity risk.

Objective: We examined the association between dietary sodium, total fluid, and SSB consumption in a nationally representative sample of US children and adolescents aged 2–18 y.

Design: We analyzed cross-sectional data from NHANES 2005–2008. Dietary sodium, fluid, and SSB intakes were assessed with a 24-h dietary recall. Multiple regression analysis was used to assess associations between sodium, fluid, and SSBs adjusted for age, sex, race-ethnic group, body mass index (BMI), socioeconomic status (SES), and energy intake.

Results: Of 6400 participants, 51.3% (n = 3230) were males, and the average (±SEM) age was 10.1 ± 0.1 y. The average sodium intake was 3056 ± 48 mg/d (equivalent to 7.8 ± 0.1 g salt/d). Dietary sodium intake was positively associated with fluid consumption (r = 0.42, P < 0.001). After adjustment for age, sex, race-ethnic group, SES, and BMI, each additional 390 mg Na/d (1 g salt/d) was associated with a 74-g/d greater intake of fluid (P < 0.001). In consumers of SSBs (n = 4443; 64%), each additional 390 mg Na/d (1 g salt/d) was associated with a 32-g/d higher intake of SSBs (P < 0.001) adjusted for age, sex, race-ethnic group, SES, and energy intake.

Conclusions: Dietary sodium is positively associated with fluid consumption and predicted SSB consumption in consumers of SSBs. The high dietary sodium intake of US children and adolescents may contribute to a greater consumption of SSBs identifying a possible link between dietary sodium intake and excess energy intake.

Health labelling can influence taste perception and use of table salt for reduced-sodium products

Objective : To investigate the effect of front-of-pack labels on taste perception and use of table salt for currently available and sodium-reduced soups.

Design : Within-subject design.

Setting : Sensory laboratory.

Subjects : Participants (n 50, mean age 34·8 (sd 13·6) years) were randomly served nine soups (250 ml each) across 3 d. Servings differed in: (i) health label (i.e. no health label, reduced-salt label or Heart Foundation Tick); and (ii) sodium reduction (no reduction – benchmark, 15 % less sodium or 30 % less sodium). Before tasting, participants rated their expected salt intensity and liking. After tasting, participants rated their perceived salt intensity and liking, after which they could add salt to the soup to make it more palatable.

Results : Reduced-salt labels generated a negative taste expectation and actual taste experience in terms of liking (P < 0·05) and perceived saltiness (P < 0·05). Perceived saltiness of sodium-reduced soups decreased more (P < 0·05), and consumers added more salt (P < 0·05), when soups carried the reduced-salt label. The tick logo and soups without health labels had no such influence on taste perception.

Conclusions : Emphasizing salt reduction by means of a front-of-pack label can have a negative effect on taste perception and salt use, especially when consumers are able to taste differences between their regular soup and the sodium-reduced soup. Overall health logos which do not emphasize the reduction in salt are less likely to affect perceived salt intensity and therefore are viable solutions to indicate the healthiness of sodium-reduced products.