Proton and molecular permeation through the basal plane of monolayer graphene oxide.

Two-dimensional (2D) materials offer a prospect of membranes that combine negligible gas permeability with high proton conductivity and could outperform the existing proton exchange membranes used in various applications including fuel cells. Graphene oxide (GO), a well-known 2D material, facilitates rapid proton transport along its basal plane but proton conductivity across it remains unknown. It is also often presumed that individual GO monolayers contain a large density of nanoscale pinholes that lead to considerable gas leakage across the GO basal plane. Here we show that relatively large, micrometer-scale areas of monolayer GO are impermeable to gases, including helium, while exhibiting proton conductivity through the basal plane which is nearly two orders of magnitude higher than that of graphene. These findings provide insights into the key properties of GO and demonstrate that chemical functionalization of 2D crystals can be utilized to enhance their proton transparency without compromising gas impermeability.

Anomalous n-type electrical behaviour of Pd-contacted CNTFET fabricated on small-diameter nanotube.

A Pd-contacted dopant-free CNTFET with small-diameter (0.57 nm) carbon nanotube showing an anomalous n-type electrical characteristic is reported for the first time. This observed behaviour is attributed to a carbon nanotube work function higher than (or close to) palladium as well as a large hole-to-electron effective mass ratio of approximately 2.5 predicted by hybridization in small-diameter nanotubes. A variation of the conduction type with temperature is also observed and is attributed to an increase of the palladium work function and decrease of the CNT work function with increasing temperature.

Performance, livability, and carcass yield of slow- and fast-growing chicken genotypes fed low-nutrient or standard diets and raised indoors or with outdoor access.

Two experiments were conducted to assess the effect of genotype, production system, and nutrition on performance and livability of meat chickens for niche markets. Slow-growing (SG) and fast-growing genotypes (FG) were raised for 91 and 63 d, respectively, in experiment 1 (females) or 84 and 56 d, respectively, in experiment 2 (males). In each trial, SG were placed before FG to achieve a similar BW at processing. In experiment 1, each genotype was assigned to 8 pens of 20 birds each, with 4 pens within each genotype raised indoors in a conventional research facility or in a small facility with outdoor access. All birds were fed a low-nutrient diet. In experiment 2, genotype assignment to pens was as in experiment 1; however, 4 pens within each genotype were fed a low-nutrient diet or a conventional diet, and birds were raised indoors. Birds were gait-scored and commercially processed; legs were examined for tibial dyschon-droplasia lesions and scanned for bone mineral density. In experiment 1, FG gained more weight than SG (P < 0.05) even though they were placed later. Outdoor access increased feed intake, and feed efficiency was poorer (P< 0.05). Fast-growing genotypes had higher breast meat yield, whereas SG had higher wing and leg yields (P < 0.05). In experiment 2, the low-nutrient diet reduced (P< 0.05) gain of the SG; FG increased feed intake of the low-nutrient diet such that their gain was unaffected (P> 0.05). For FG, the low-nutrient diet resulted in a poorer (P < 0.05) feed efficiency. Although weight gain of the FG was maintained on the low-nutrient diet, breast yield was reduced (P < 0.05). Genotype affected bone health in both experiments, with SG having better gait scores and less tibial dyschondroplasia (P < 0.05). Outdoor access and the low-nutrient diet also resulted in better gait score (P < 0.05). These data indicate differences among genotypes and provide information about the efficiency and potential for alternative poultry systems.

Sensory attributes of slow- and fast-growing chicken genotypes raised indoors or with outdoor access.

Consumer interest in free-range and organic poultry is growing. An experiment was conducted to assess the impact of alternative genotype and production systems on the sensory attributes of chicken meat. Specifically, a slow-growing genotype and a fast-growing genotype were raised for 91 and 63 d. The slow-growing birds were placed before the fast-growing birds to achieve a similar final BW at processing. Each genotype was assigned to 4 pens of 20 birds each and raised in indoor floor pens in a conventional research facility; each genotype was also assigned to 4 floor pens in a small facility with outdoor access. The diet was formulated to be low in energy and protein for slow growth. Birds were commercially processed and deboned at 4 h postmortem. A descriptive analysis of breast and thigh meat was conducted on all treatments by a trained descriptive panel. A consumer analysis was also conducted on the breast and thigh meat from only 2 treatments: slow-growing birds raised with outdoor access and fast-growing birds raised indoors. A descriptive analysis indicated that the breast meat from birds with outdoor access was more cohesive than the meat from indoor birds (P < 0.05). There were no significant differences for most basic tastes; however, both the breast meat and thigh meat of the fast-growing birds tasted saltier than that of the slow-growing birds (P < 0.05). Meat of the slow-growing birds had more dark meat fat flavor than that of the fast-growing birds (P < 0.05). Results from the consumer panel showed no significant differences in overall liking, appearance, texture, or flavor of the breast meat or thigh meat. Just-About-Right distributions of consumer responses did not vary between slow-growing birds with outdoor access and fast-growing birds raised indoors for most attributes; however, more panelists found the breast meat of slow-growing birds with outdoor access too dry (P < 0.05). Although a descriptive panel detected some differences in texture and flavor among treatments, the consumer panel did not indicate differences in liking between conventional and specialty products.

Meat quality of slow- and fast-growing chicken genotypes fed low-nutrient or standard diets and raised indoors or with outdoor access.

Consumer interest in free-range and organic poultry is growing. Two concurrent experiments were conducted to assess 1) the impact of alternative genotype and production system and 2) the impact of genotype and diet on meat quality of chickens for specialty markets. Specifically, a slow-growing genotype (slow) and a fast-growing genotype (fast) were raised for 91 and 63 d (females), respectively, or 84 and 56 d in the case of the second trial (males). In each trial, the slow birds were placed before the fast birds to achieve a similar final BW at processing. Each genotype was assigned to 4 pens of 20 birds each and raised in indoor floor pens in a conventional poultry research facility; each genotype was also assigned to 4 floor pens in a small facility with outdoor access. A low-nutrient diet was used, formulated for a slower rate of production. Birds were commercially processed and deboned at 4 h postmortem. In the second trial, the diets compared were a conventional diet that met NRC requirements or the low-nutrient diet, and all birds were raised indoors. There was an interaction between genotype and production system for the color (b*; P < 0.05). The meat and skin of the slow birds became more yellow when the birds had outdoor access; however, this did not occur when the fast birds had outdoor access. The breast meat of the slow birds had more protein and alpha-tocopherol (P < 0.05) than the fast birds and half the amount of fat (P < 0.05). In addition, the meat of the outdoor birds had more protein than the indoor birds (P < 0.05). The slow birds had poorer water-holding capacity but were more tender than the fast birds (P < 0.05). The type of diet had little impact on meat quality. These data indicate that meat quality differences exist between genotypes with different growth rates and raised in alternative production systems.

Evaluation of the efficacy of vitamin D3 or its metabolites on thiram-induced tibial dyschondroplasia in chickens.

Two trials were conducted to determine if thiram-induced tibial dyschondroplasia (TD) in chickens was linked to a vitamin D deficiency and calcium homeostasis dysregulation, and whether feeding vitamin D fortified diets may prevent it. Day-old chickens were given grower diets containing different vitamin D products throughout the experiment until necropsy on day 16. Half of the birds in each feed group received thiram at levels of 100 ppm (trial 1) or 50 ppm (trial 2) between days 7-9 to induce TD. The birds were weighed, bled, and euthanized to determine TD incidences and severity by examining the growth plates. Tibial bones were used to measure biomechanical strength and ash content. Blood concentrations of 25-hydroxyvitamin D, Ca, P, alkaline phosphatase, and creatine kinase were measured in serum that showed no differences between different groups. Thiram reduced body weight and induced TD regardless of any vitamin D treatment to the same extent as untreated birds.

Homocysteine remethylation in broilers fed surfeit choline or betaine and varying levels and sources of methionine from eight to twenty-two days of age.

Experiments were conducted to assess the effect of surfeit choline (CHOL) or betaine (BET) on growth performance and homocysteine (HCY) remethylation of young broilers fed graded levels of DL-Met (DLM) or 2-hydroxy-4-(methylthio) butanoic acid (HMB). In Experiment 1, a corn-peanut meal diet deficient in Met (0.25% digestible) and Cys (0.28% digestible) was fed; treatments were formulated to contain graded levels (0, 0.04, or 0.08%) of Met from DLM or 0.04% HMB (adjusted for 88% purity) that were fed in the presence or absence of surfeit isomethyl CHOL (0.25%) or BET (0.28%). In Experiment 2, identical treatments were used, but an additional level of HMB (0.08%) was fed, and the basal diet was adequate in Cys (0.43% digestible). There was no overall effect of CHOL or BET on growth performance in Experiments 1 and 2 (P > 0.05); a significant improvement (P < 0.05) in weight gain and feed efficiency did occur with CHOL and BET addition to the basal diet in Experiment 2. In both experiments, weight gain increased linearly (P < 0.05) with the addition of DLM or HMB. Slope ratio methodology was used to assess HMB efficacy in Experiment 2. In the presence of adequate Cys, HMB efficacy was 81.3%; addition of surfeit BET or CHOL had minimal effect on efficacy. The stable isotope study revealed that CHOL and BET addition to diets deficient in Met and Cys or Met alone increased HCY remethylation. It also showed that CHOL and BET have greater influence on folate-dependent remethylation of HCY (via Met synthase) than on BET-dependent remethylation (via BET-HCY methyltransferase) and that levels of CHOL and BET and type of S amino acid deficiency effect remethylation and HMB efficacy.

Efficacy of an Escherichia coli phytase in broilers fed adequate or reduced phosphorus diets and its effect on carcass characteristics.

Five experiments (EXP) were conducted to assess the efficacy of an Escherichia coli phytase compared with 2 commercially available fungal phytases. In EXP 1 and 2, male broiler chicks were fed experimental diets that included a P-deficient control (0.13% available P; 0.88% Ca) alone or with graded levels of KH(2)PO(4) (0, 0.05, 0.10, or 0.15%) or phytase at levels of 250, 500, 1,000, 2,000, or 4,000 phytase units/kg of E. coli phytase (EXP 1 and 2), fungal phytase 1 (EXP 2), or fungal phytase 2 (EXP 2). In EXP 1 and 2, weight gain and tibia ash (mg/chick and %) responded linearly (P < 0.05) to inorganic P addition. In EXP 2, each level of E. coli phytase released more P than either fungal phytases 1 or 2, whether based on tibia ash weight (mg/chick) or percentage. In EXP 3, 4, and 5, dietary treatments containing adequate or deficient levels of P were fed with or without supplemental E. coli phytase. In EXP 3, weight gain and tibia ash were reduced (P < 0.05) by P deficiency, but gain and tibia ash of chicks fed E. coli phytase (250, 500, or 1,000 phytase units/kg) did not differ (P > 0.05) from that of chicks fed the P-adequate diet. In addition, carcass yield of broilers fed E. coli phytase was not reduced (P > 0.05). In EXP 4, E. coli phytase effectively supported weight gain, tibia ash, breast yield, and leg yield compared with birds fed the P-adequate diet, but clavicle breakage during processing was increased in birds fed E. coli phytase. In EXP 5, E. coli phytase again effectively supported weight gain, and no differences (P > 0.05; compared with the P-adequate diet) were noted for clavicle ash, diameter, or breaking strength. No differences (P > 0.05) in bone breakage during processing were noted among treatments. These results indicate that the addition of E. coli phytase to P-deficient broiler diets improves growth, bone, and carcass performance and is more effective at releasing phytate-bound P than the other phytase products that were tested.

Effect of reciprocating dietary lysine fluctuations on chick growth and carcass yield.

Three experiments (Exp) were conducted to study the effect of reciprocating (i.e., back-and-forth) fluctuations in dietary Lys concentration on growth performance of male broiler chicks. The Lys, CP, and ME concentrations were fluctuated in Exp 1 by varying corn and soybean meal concentrations. Corn-peanut meal diets in Exp 2 and 3 contained a constant calorie-protein ratio, but Lys concentrations were fluctuated by varying supplemental L-Lys x HCl. During 7-d feeding periods from d 8 to 43 posthatch, chicks fed the fluctuating regimen were provided diets with nutrient concentrations arranged in the following order (relative to control diets at any given point): excess-deficient-excess-deficient-adequate. In each Exp, differences in feed intake and gain:feed were observed during the first 7 d. Weight gain was never affected by dietary regimen. Overall, chicks fed the fluctuating regimen showed similar weight gain and feed intakes relative to chicks fed the control regimen. Additionally, efficiency of feed, Lys, CP, and ME utilization over the 35-d growth period of Exp 2 and 3 were not affected by dietary regimen. An increase in carcass yield (dressed, carcass weight as a percentage of live weight) of birds fed the fluctuating regimen was observed, but there were no differences in abdominal fat yield (as a percentage of dressed, carcass weight). These data support the conclusion that reciprocating 7-d periods of nutrient excess and deficiency do not affect overall growth performance of growing chicks.

The use of vitamin A-deficient diets and jugular vein ligation to increase intracranial pressure in chickens (Gallus gallus).

A technique was developed to record intracranial cerebrospinal fluid pressure (iCSFp) in chicks and mature chickens. Using that procedure, 2 methods were found to effect a significant elevation in intracranial pressure: 1) feeding a purified diet to roosters for 40 d containing 25% of the bird's requirement for vitamin A, and 2) ligating both jugular veins in birds. The purified diet significantly reduced plasma retinol levels from 1.080 to 0.046 microg/mL, and iCSFp was significantly elevated from 63.0 to 106.0 mmH2O (P < or = 0.05). Two limitations for using hypovitaminosis A diets were capillary fragility and a cisterna magna that did not develop to the size of that structure in birds of the same age fed control diets with adequate vitamin A content. The second procedure, a reversible surgical technique, showed that within 2.5 h from jugular vein ligation, intracranial pressure rose to 109.7 mmH2O, comparable with levels attained following feeding a vitamin A deficient diet to roosters. Bilateral clamping of the jugular veins overnight resulted in an elevation of iCSFp to 127 +/- 8.86 mmH2O. Results suggest that the chicken may be a useful animal model to investigate intracranial hypertension and its accompanying headaches known to occur in humans.

Evaluation of slower-growing broiler genotypes grown with and without outdoor access: sensory attributes.

Consumer interest in organic and natural poultry production is growing. An experiment was conducted to assess the impact of genotype and outdoor access on sensory attributes of broiler meat. One slow-growing genotype (S), 2 medium-growing genotypes (M1 and M2), and a commercial fast-growing genotype (F) were raised (straight-run) for 81, 67, or 53 d, respectively. The placement dates were staggered to achieve a similar final BW, and each genotype was processed on the same day. Each genotype was assigned to 3 pens of 24 birds each, and all birds were raised in indoor floor pens in a naturally ventilated facility. The S and F genotypes were also assigned to 2 floor pens with outdoor access (during daylight hours) containing 36 birds each. All birds were provided with the same starter, grower, and finisher feeds, and birds were commercially processed. Breast and thigh meat were evaluated for sensory attributes and acceptability by a consumer panel. The M1 and M2 breasts were more tender than other indoor genotypes (P < 0.05); however, all treatments scored "slightly to moderately tender." The thigh meat of the M2 birds was more flavorful than that of S birds (P < 0.05), and the flavor of the S thigh meat was less liked than other indoor genotypes (P < 0.05). Outdoor access did not impact flavor. These data indicate that differences in sensory attributes may exist among genotypes with different growth rates and reared with or without outdoor access.

Homocysteine remethylation in young broilers fed varying levels of methionine, choline, and betaine.

Methionine is critical in amino acid nutrition for chickens, yet details of the flux of Met metabolites in the avian system are lacking. This study explored the interactions among dietary choline (CHO), betaine (BET), and sulfur amino acid levels on growth and hepatic homocysteine (HCY) remethylation. Graded levels (0, 0.07, 0.11, and 0.24%) of DL-Met were added to diets adequate in CHO and deficient in sulfur amino acids (0.26% digestible Met, 0.26% digestible Cys). Each Met level was tested alone or with the addition of CHO (0.25%) or BET (0.28%). Broilers were reared from 8 to 22 d in raised wire floor battery cages, and the 12 dietary treatments were fed to 3 replicate pens containing 5 birds per pen. Weight gain and feed efficiency were maximized (P < 0.05) with addition of 0.11% supplemental Met, whereas feed intake was maximized (P < 0.05) with addition of 0.07% supplemental Met. Overall, growth parameters were not affected (P > 0.05) by CHO or BET addition. Hepatic tissue primed by the different dietary treatments was subjected to a newly developed stable isotope methodology and HPLC-mass spectrometry to quantify the impact of diet on HCY remethylation. Dietary Met level did not (P > 0.05) affect HCY remethylation, but remethylation through the Met synthase pathway was increased (P < 0.05) by addition of CHO or BET to diets containing deficient or excess levels of Met. Minimal changes in hepatic HCY remethylation through the betaine-homocysteine methyltransferase pathway occurred in response to dietary changes; therefore, data failed to support previous suggestions that BHMT might have a regulatory role when diets containing deficient or excess Met levels are fed. In contrast to previous suppositions based on enzyme activity, under most dietary conditions, the quantity of HCY remethylated by Met synthase appeared to exceed that remethylated by the alternate betaine-homocysteine methyltransferase pathway.

Evaluation of slower-growing broiler genotypes grown with and without outdoor access: growth performance and carcass yield.

Consumer interest in organic and free-range poultry production is growing. An experiment was conducted to assess the impact of genotype and outdoor access on growth rate and carcass yield. One slow-growing genotype (S), 2 medium-growing genotypes (M1 and M2), and a commercial fast-growing genotype (F) were raised (straight-run) for 81, 67, and 53 d, respectively. The placement date was staggered in order to achieve a similar final body weight and each genotype was processed on the same day. Each genotype was assigned to 3 pens of 24 birds each and raised in indoor floor pens in a curtain-sided house with ventilation fans; the S and F genotypes were also assigned to 2 floor pens with outdoor access (during daylight hours) containing 36 birds each. All birds were provided with the same starter, grower, and finisher feeds, and birds were commercially processed. Weight gain was similar (P > 0.05) among genotypes, but males gained more weight (P < 0.05) than females. The S and F genotypes had the highest and lowest (P < 0.05) feed intakes and, consequently, the lowest and highest (P < 0.05) feed efficiencies, respectively. The F genotype had the greatest (P < 0.05) breast yield (%) and the lowest (P < 0.05) wing yield (%). The S genotype exhibited the lowest (P < 0.05) breast yield (%) and the greatest leg quarter yield (%). Birds given outdoor access had greater (P < 0.05) bone strength in the tibia, and the F genotype had highest (P < 0.05) bone strength. These data indicate that substantial growth performance and yield differences exist among genotypes in alternative poultry systems.

Evaluation of slower-growing broiler genotypes grown with and without outdoor access: meat quality.

Consumer interest in organic and natural poultry products raised with outdoor access is growing. An experiment was conducted to assess the effects of outdoor access and genotype on meat quality. One slow-growing genotype (S), 2 medium-growing genotypes (M1 and M2), and a commercial fast-growing genotype (F) were raised (straight-run) for 81, 67, or 53 d, respectively. The placement date was staggered in order to achieve a similar final body weight. Each genotype was assigned to 3 pens of 24 birds each and raised in indoor floor pens in a naturally ventilated facility; the S and F genotypes were also assigned to 2 floor pens with outdoor access containing 36 birds each. All birds were provided with the same starter, grower, and finisher feeds, and birds were commercially processed. Pectoralis samples were collected at 6 h postmortem for proximate analysis and evaluation of meat quality. The principal effect of outdoor access was to make the meat more yellow in the case of the S genotype (P < 0.05) although not the F genotype (P > 0.05). Drip loss and cook loss (%) were affected (P < 0.05) by genotype, with the highest losses occurring with the S genotype and the lowest losses occurring with the F and M genotypes. Tenderness was affected (P < 0.05) by gender as well as production system but only in the F birds. Pectoralis dry matter (%), fat (%), and ash (%) were largely unaffected (P > 0.05) by genotype or outdoor access. These data indicate that meat quality differences exist among genotypes with very different growth rates and reared with or without outdoor access.

Growth performance and nitrogen excretion of broilers using a phase-feeding approach from twenty-one to sixty-three days of age.

Two experiments were conducted to assess effects of phase-feeding (PF) on broilers from 21 to 63 d. Experiment 1 evaluated the impact of PF on growth performance, whereas experiment 2 assessed the effects of PF on CP intake and nitrogen excretion. Diets were formulated using recommendations from NRC or linear regression equations. Two PF treatments were prepared: standard (PF) and low (PF10), in which predicted Lys, sulfur amino acid, and Thr recommendations were reduced by 10%. For PF and PF10, 2 diets (high-nutrient and low-nutrient density) were blended in variable quantities to produce rations matching predicted requirements. An NRC grower and finisher diet or a series of PF and PF10 diets that were switched every other day were fed. In experiment 1, weight gain and feed efficiency were improved (P < 0.05) by PF10 relative to broilers fed the NRC-based diet. Crude protein intake was reduced (P < 0.05) by PF10 relative to broilers fed NRC and PF diets. No differences (P > 0.05) in percentage carcass composition were observed when broilers were fed PF or PF10 diets. Significant reductions (P < 0.05) in dollars per kilogram of weight gain were noted with PF regimens. In experiment 2, PF and PF10 diets reduced (P < 0.05) CP intake and nitrogen excretion from 43 to 63 d. Results indicate that PF regimens may substantially reduce dietary costs and may have environmental benefits.

IMPACT OF EDUCATION OF PARENTS ON NUTRITIONAL STATUS OF PRIMARY SCHOOL CHILDREN.

In a cross-sectional study the nutritional status of 2585 school children, including 1253 boys and 1332 girls, aged between 5 and 15 years was correlated with the levels of literacy of their parents. The study showed a direct relationship between the levels of literacy of parents and the nutritional status of children. When the same was tested separately for mothers and fathers in relation to the sex of the child, it was noted that nutritional status of boys and girls was not different irrespective of mother's literacy level. However, in case of fathers it was noticed that with the Increase in the literacy level of fathers, the nutritional status of boys was better than that of girls.

ANALYTICAL REVIEW OF: REVIEW MEDICAL BOARDS (RMB) CARRIED OUT DURING 1993-98.

The medical fitness of the candidates selected for officers' training institutes of three wings of Armed Forces is assessed by special medical boards(SMBs) and appeal medical boards (AMBs). The candidates declared unfit at AMBs arc given one more chance to prove their medical fitness, if they so desire, at an another board, designated as review medical board (RMB). RMB is sanctioned by DGAFMS based on merit of the case and as per the provisions of para 482 of RMSAF -1983. The venue of RMB is either at AFMC Pune or at Army Hospital (R&R) Delhi. RMB documents for the period from 1993-98 were analysed. During this period 338 requests for RMB were received, out of which 173 cases were given sanction (51.69%) for RMB. The average percentage of fitness in RMB among the total requests was 25.73%. There was no significant difference in the percentage of fitness between the RMBs held at AFMC Pune and Army Hospital (R&R) Delhi. Thus the paper goes to prove its usefulnesss to the candidates as well as to services and its fairness.

NUTRITIONAL STATUS OF GIRL CHILD A COMPARATIVE STUDY IN PRIMARY SCHOOL CHILDREN.

In order to determine the nutritional status of school children, 2585 students were examined clinically and a diet survey was carried out on a subsample of 200 children. Severe undernourishment, wasting and stunting were encountered in 8.93%, 0.90% and 1.35% of girls as against 8.78%, 0.32% and 1.20% of boys respectively. In girls, dietary inadequacy was more pronounced and signs of nutritional disorders were more frequent. Such a finding is a pointer towards disparity in nutrition.

STUDY ON INTEROBSERVER AGREEMENT IN A GOITRE PREVALENCE SURVEY.

Observers differ in their judgment while assessing physical signs in a patient. We had undertaken a goitre prevalence survey amongst school students in a Rural Health Training Centre, Pune district (Maharashtra) during October 1992. Four teams of trained observers were used for detection of goitre. This study was undertaken to estimate the extent and acceptability of interobserver agreement amongst the four teams. Observer variation/agreement was measured by two methods viz. kappa coefficient and proportion of agreement. The proportion of agreement appears to be a better measure of observer agreement as it could make a distinction between normality (absence of goitre) and abnormality (presence of goitre). In the present study, the proportion of agreement for abnormality ranged between 0.62 - 0.83. This measure was considered as indicating a good interobserver agreement in detecting goitre in the survey that was undertaken.