Properties of antibacterial bioboard from bamboo macromolecule by hot press

Bamboo macromolecules were pretreated with bamboo vinegar, which has an antibacterial property, and processed into antibacterial bioboard (ABB) by hot pressing. The ABB was then analyzed by conducting Fourier-transform infrared spectroscopy, thermogravimetric analysis and differential thermal analysis. Results showed that ABB samples had average density of 1.0 g/cm³, which is appropriate for application. The physical and mechanical properties were best for the ABB sample pretreated with bamboo vinegar and hot pressed at 165 °C for 10 min. Fourier-transform infrared spectroscopy revealed that the optimum conditions for hot pressing were a temperature of 165 °C, duration of 10 min, and the addition of bamboo vinegar. Thermogravimetric analysis/differential thermal analysis curves indicated that the thermal degradation of the ABB was less than that of bamboo, revealing that hot pressing increased the thermal stability of ABB samples. Analysis revealed that pretreatment with bamboo vinegar improved the antibacterial property of the ABB.     

Bacterial community analysis in chlorpyrifos enrichment cultures via DGGE and use of bacterial consortium for CP biodegradation

The organophosphate pesticide chlorpyrifos (CP) has been used extensively since the 1960s for insect control. However, its toxic effects on mammals and persistence in environment necessitate its removal from contaminated sites, biodegradation studies of CP-degrading microbes are therefore of immense importance. Samples from a Pakistani agricultural soil with an extensive history of CP application were used to prepare enrichment cultures using CP as sole carbon source for bacterial community analysis and isolation of CP metabolizing bacteria. Bacterial community analysis (denaturing gradient gel electrophoresis) revealed that the dominant genera enriched under these conditions were Pseudomonas, Acinetobacter and Stenotrophomonas, along with lower numbers of Sphingomonas, Agrobacterium and Burkholderia. Furthermore, it revealed that members of Bacteroidetes, Firmicutes, α- and γ-Proteobacteria and Actinobacteria were present at initial steps of enrichment whereas β-Proteobacteria appeared in later steps and only Proteobacteria were selected by enrichment culturing. However, when CP-degrading strains were isolated from this enrichment culture, the most active organisms were strains of Acinetobacter calcoaceticus, Pseudomonas mendocina and Pseudomonas aeruginosa. These strains degraded 6–7.4 mg L^?1 day^?1 of CP when cultivated in mineral medium, while the consortium of all four strains degraded 9.2 mg L^?1 day^?1 of CP (100 mg L^?1). Addition of glucose as an additional C source increased the degradation capacity by 8–14 %. After inoculation of contaminated soil with CP (200 mg kg^?1) disappearance rates were 3.83–4.30 mg kg^?1 day^?1 for individual strains and 4.76 mg kg^?1 day^?1 for the consortium. These results indicate that these organisms are involved in the degradation of CP in soil and represent valuable candidates for in situ bioremediation of contaminated soils and waters.     

New head models extracted from thermal infrared (IR) images for dosimetry computations

In electromagnetic dosimetry, anatomical human models are commonly obtained by segmentation of magnetic resonance imaging or computed tomography scans. In this paper, a human head model extracted from thermal infrared images is examined in terms of its applicability to specific absorption rate (SAR) calculations. Since thermal scans are two-dimensional (2D) representation of surface temperature, this allows researchers to overcome the extensive computational demand associated with 3D simulation. The numerical calculations are performed using the finite-difference time-domain method with mesh sizes of 2 mm at 900 MHz plane wave irradiation. The power density of the incident plane wave is assumed to be 10 W/m². Computations were compared with a realistic anatomical head model. The results show that although there were marked differences in the local SAR distribution in the various tissues in the two models, the 1 g peak SAR values are approximately similar in the two models.     

Direct discrimination of different plant populations and study on temperature effects by Fourier transform infrared spectroscopy

Fourier transform infrared spectroscopy was used to characterise highland and lowland populations of Polygonum minus Huds. grown in different controlled environments. A thermal perturbation technique of two-dimensional correlation infrared spectroscopy (2D-IR) correlation spectra was applied to establish differences between the populations. The absorption peaks at 3,480 cm^?1 (hydroxyl group), 2,927 cm^?1 (methyl group), 1,623 cm^?1 (carbonyl group), and 1,068 cm^?1 (C–O group) were particularly powerful in separating the populations. These peaks, which indicate the presence of carbohydrate, terpenes, amide and flavonoids were more intense for the highland populations than lowland populations, and increased in environments with a higher temperature. Wavenumbers (1,634, 669 cm^?1) and (1,634, 1,555 cm^?1) in the 2D-IR correlation spectra provided fingerprint signals to differentiate plants grown at different temperatures. This study demonstrates that IR fingerprinting, which combines mid-IR spectra and 2D-IR correlation spectra, can directly discriminate different populations of P. minus and the effects of temperature.     

Sensible heat transfer and thermal windows in Dasyprocta leporina (Mammalia,Rodentia)

This study aimed to evaluate the diurnal variation of the sensible heat transfer in red-rumped agoutis (Dasyprocta leporina) bred in captivity in a semi-arid environment. In addition, we seek to identify thermal windows by infrared thermography during the daytime period (07:00, 09:00, 11:00, 14:00, and 16:00). The body surface temperature was higher in the pinna (36.84 ± 0.11 °C), followed by the hind limbs (36.55 ± 0.11 °C). These body regions were primarily responsible for heat loss by radiation (which was 10.13 ± 1.17 W m^?2 and 11.19 ± 1.17 W m^?2, respectively), and acted like biological thermal windows. Heat transfer by convection was more intense in the body trunk and hind limbs at all times of the day. Thus, sensible heat transfer is important for maintaining homeothermy in red-rumped agouti in hot environments. In conclusion, these rodents use specialized body regions (pinna and hind limbs) for heat transfer.     

The emission of floral scent from Lilium ‘siberia’ in response to light intensity and temperature

Floral scent is an important part of volatile compounds emitted from plants, and is influenced by many environmental factors. In this study, the floral scent emitted from Lilium ‘siberia’, a common breed of lily, was collected by dynamic headspace at different levels of light intensity (0, 100, 300, 600, 1,000, and 1,500 μmol m^?2 s^?1) and temperature (10, 20, 30, and 40 °C). Using the automated thermal desorption-gas chromatography/mass spectrometry (ATD-GC/MS) technique, the components and release amounts were subsequently identified to investigate the influence of light and temperature on the emission of floral scent. The results revealed that the numbers and release amounts of floral scent components were significantly influenced by light intensity and temperature, showing the similar pattern: first increasing and then decreasing. After light intensity treatment, the maximum numbers and release amounts mainly appeared at 600 and 1,000 μmol m^?2 s^?1. For temperature treatment, 30 °C resulted in the highest numbers and release amounts of the floral scent components. At different levels of light intensity and temperature, terpenoid compounds showed the highest numbers and release amounts among the component categories. α-Ocimene and linalool were the two terpenoid compounds with the highest release amounts, and accounted for the highest proportion. The results obtained provide evidence that both light intensity and temperature trigger the emission of floral scent. The particular response mechanisms must be investigated in future research.     

OSL and thermally assisted OSL response in dental enamel for its possible application in retrospective dosimetry

Dental enamel was studied for its thermoluminescence (TL) and optically stimulated luminescence (OSL) defects. The TL studies showed a wide glow curve with multiple peaks. The thermally assisted OSL (TA-OSL) studies showed that the integrated TA-OSL and thus OSL signal increases with readout temperature between 100 and 250 °C, due to the temperature dependence of OSL. The thermally assisted energy E _A associated with this increase is found to be 0.21 ± 0.015 eV. On the other hand, the signal intensity decreases with temperature between 260 and 450 °C. This decrease could be due to depletion of OSL active traps or possible thermal quenching. The increase of the OSL signal at increased temperature can be used to enhance the sensitivity of dental enamel for ex vivo measurements in retrospective dosimetry. The emission and excitation spectra of its luminescence centers were studied by photoluminescence and were found to be at 412 and 324 nm, respectively. It was found to possess multiple OSL active traps having closely lying photoionization cross sections characterized by continuous wave OSL and nonlinear OSL methods. The investigated dental enamel samples showed a linear OSL dose response up to 500 Gy. The dose threshold was found to be 100 mGy using a highly sensitive compact OSL reader with blue LED (470 nm) stimulation.     

Enhanced Thermal Stability of W‐Ni‐Al2O3 Cermet‐Based Spectrally Selective Solar Absorbers with Tungsten Infrared Reflectors

Solar thermal technologies such as solar hot water and concentrated solar power trough systems rely on spectrally selective solar absorbers. These solar absorbers are designed to efficiently absorb the sunlight while suppressing re‐emission of infrared radiation at elevated temperatures. Efforts for the development of such solar absorbers must not only be devoted to their spectral selectivity but also to their thermal stability for high temperature applications. Here, selective solar absorbers based on two cermet layers are fabricated on mechanically polished stainless steel substrates using a magnetron sputtering technique. The targeted operating temperature is 500–600 °C. A detrimental change in the morphology, phase, and optical properties is observed if the cermet layers are deposited on a stainless steel substrate with a thin nickel adhesion layer, which is due to the diffusion of iron atoms from the stainless steel into the cermet layer forming a FeWO₄ phase. In order to improve thermal stability and reduce the infrared emittance, tungsten is found to be a good candidate for the infrared reflector layer due to its excellent thermal stability and low infrared emittance. A stable solar absorptance of ≈0.90 is demonstrated, with a total hemispherical emittance of 0.15 at 500 °C.     

The association of apolipoprotein E gene polymorphisms with cerebral palsy in Chinese infants

Apolipoprotein E (APOE, protein; ApoE, gene) is a lipid transport protein abundantly present in brain cells. Previous studies have suggested that there is an association between genetic variants of ApoE and susceptibility to cerebral palsy (CP). The purpose of this study was to explore whether the ApoE gene is involved in the etiology of CP in the Chinese population. In this study, 350 CP patients and 242 healthy control children were recruited. Genomic DNA was prepared from venous blood and all five single nucleotide polymorphisms (SNPs) in ApoE (rs769446, rs405509, rs121918399, rs429358, and rs190853081) were detected by the MassARRAY platform-based genotyping approach. The SHEsis program was used to analyze the genotyping data, and we systemically analyzed the association of the ApoE SNPs with different subtypes of CP. No significant association was detected between the e4 identified by the C allele of rs429358 and CP, but there were significant differences in allelic frequencies between the CP patients and controls at rs769446 (P = 0.005, P = 0.025 after Bonferroni correction), as well as between the CP patients with preterm birth (<34 gestational weeks) and controls at rs769446 (P = 0.001, P = 0.005 after Bonferroni correction). A haplotype consisting of the five SNPs rs769446(C), rs405509(C), rs121918399(C), rs429358(T), and rs190853081(G) was associated with a decreased risk of CP (P = 0.002 after Bonferroni correction). However, we found no significant association between any of the other three SNPs and CP based on different subgroup analyses. This study provides the first evidence that ApoE gene polymorphisms are a potential risk factor for CP in the Chinese population.     

Optimization of monomethoxy polyethyleneglycol-modified oxalate decarboxylase by response surface methodology

In order to improve the stability of oxalate decarboxylase (Oxdc), response surface methodology (RSM), based on a four-factor three-level Box-Behnken central composite design was used to optimize the reaction conditions of oxalate decarboxylase (Oxdc) modified with monomethoxy polyethyleneglycol (mPEG5000). Four independent variables such as the ratio of mPEG-aldehyde to Oxdc, reaction time, temperature, and reaction pH were investigated in this work. The structure of modified Oxdc was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared (FTIR) spectroscopy, the stability of the modified Oxdc was also investigated. The optimal conditions were as follows: the mole ratio of mPEG-aldehyde to Oxdc of 1:47.6, time of 13.1 h, temperature at 29.9 °C, and the reaction pH of 5.3. Under optimal conditions, experimental modified rate (MR = 73.69%) and recovery rate (RR = 67.58%) were matched well with the predicted value (MR = 75.11%) and (RR = 69.17%). SDS-PAGE and FTIR analysis showed that mPEG was covalently bound to the Oxdc. Compared with native Oxdc, the modified Oxdc (mPEG-Oxdc) showed higher thermal stability and better tolerance to trypsin or different pH treatment. This work will provide a further theoretical reference for enzyme modification and conditional optimization.     

Metronomic chemotherapy with low-dose cyclophosphamide plus gemcitabine can induce anti-tumor T cell immunity in vivo

Several chemotherapeutic drugs have immune-modulating effects. For example, cyclophosphamide (CP) and gemcitabine (GEM) diminish immunosuppression by regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs), respectively. Here, we show that intermittent (metronomic) chemotherapy with low-dose CP plus GEM can induce anti-tumor T cell immunity in CT26 colon carcinoma-bearing mice. Although no significant growth suppression was observed by injections of CP (100 mg/kg) at 8-day intervals or those of CP (50 mg/kg) at 4-day intervals, CP injection (100 mg/kg) increased the frequency of tumor peptide-specific T lymphocytes in draining lymph nodes, which was abolished by two injections of CP (50 mg/kg) at a 4-day interval. Alternatively, injection of GEM (50 mg/kg) was superior to that of GEM (100 mg/kg) in suppressing tumor growth in vivo, despite the smaller dose. When CT26-bearing mice were treated with low-dose (50 mg/kg) CP plus (50 mg/kg) GEM at 8-day intervals, tumor growth was suppressed without impairing T cell function; the effect was mainly T cell dependent. The metronomic combination chemotherapy cured one-third of CT26-bearing mice that acquired tumor-specific T cell immunity. The combination therapy decreased Foxp3 and arginase-1 mRNA levels but increased IFN-γ mRNA expression in tumor tissues. The percentages of tumor-infiltrating CD45⁺ cells, especially Gr-1^high CD11b⁺ MDSCs, were decreased. These results indicate that metronomic chemotherapy with low-dose CP plus GEM is a promising protocol to mitigate totally Treg- and MDSC-mediated immunosuppression and elicit anti-tumor T cell immunity in vivo.     

A review of the history of research and control of <Emphasis Type="Italic">Rhipicephalus</Emphasis> (<Emphasis Type="Italic">Boophilus</Emphasis>) <Emphasis Type="Italic">microplus</Emphasis>, babesiosis and anaplasmosis in Uruguay

The effect of five constant temperatures (16, 20, 24, 28 and 32 °C) on the development, survival and reproduction of Tetranychus cinnabarinus (Boisduval) [=?Tetranychus urticae Koch (red form)] fed on cassava leaves was examined in the laboratory at 85% relative humidity. Development time of various immature stages decreased with increasing temperature, with total egg-to-adult development time varying from 27.7 to 6.7 days. The lower thermal threshold for development was 10.8 °C and the thermal constant from egg to adult was 142.4 degree-days. Pre- and post-oviposition period and female longevity all decreased as temperature increased. The longest oviposition period was observed at 20 °C with 20.4 days. Under different temperatures, mated females laid, on average, 1.0, 2.9, 4.7, 4.7 and 4.9 eggs per day, respectively. The maximum fecundity (81.5 eggs per female) was at 28 °C and the intrinsic rate of increase (r _m ) was highest (0.25) at 32 °C. The results of this study indicate that T. cinnabarinus population could increase rapidly when cassava leaves serve as a food source. At the appropriate temperature T. cinnabarinus could seriously threaten growth of cassava.     

Biochemical and morphological evaluation of the effects of propolis on cisplatin induced kidney damage in rats

Cisplatin (CP) is a chemotherapeutic agent used to treat various types of cancer; nephrotoxicity is the most common adverse effect of the drug. We investigated the protective effects of propolis against CP induced kidney injury. Thirty-six male rats were divided into six equal groups: untreated control group, 50 mg/kg/day propolis group, 100 mg/kg/day propolis group, single-dose 7 mg/kg CP group, 7 mg/kg CP + 50 mg/kg/day propolis and 7 mg/kg CP + 100 mg/kg propolis. Rats were sacrificed after 14 days and kidneys were removed for histopathological and biochemical analyses. We used hematoxylin & eosin and periodic acid-Schiff staining to evaluate kidney histopathology and we used the TUNEL technique to assess apoptosis. We also measured total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), ischemia-modified albumin (IMA) and malondialdehyde (MDA) levels in tissue and blood specimens. Normal morphology was observed in the control, 50 mg/kg/day propolis and 100 mg/kg/day propolis groups by light microscopy. Degeneration of tubule cells, edema and tubule dilation were increased in the CP group compared to the control group. Degeneration of tubule cells and dilation of Bowman’s spaces were decreased in the CP + 50 mg/kg/day propolis and CP + 100 mg/kg/day propolis groups compared to the CP group. Tubule dilation decreased significantly in the CP + 100 mg/kg propolis group compared to the CP group. Also, the 7 mg/kg CP group exhibited altered proximal tubule epithelial cells, loss of brush border and thickening of the parietal layer of Bowman’s capsule in glomeruli and basal laminae of tubules. A normal brush border was observed in the CP + 50 mg/kg/day propolis and CP + 100 mg/kg/day groups. Serum OSI and MDA levels were increased in the CP group compared to the control group. Serum MDA levels decreased significantly in the CP + 50 mg/kg/day propolis and 100 mg/kg CP + propolis groups compared to the CP group. CP caused significant damage to kidney tissue; propolis exhibited dose-dependent prevention of tissue damage.     

Investigations on the Thermal Stability of Fullerene-Based (Ag-C<Subscript>70</Subscript>) Nanocomposite Thin Films

Fullerene-based bi-functional nanocomposite thin film (Ag nanoparticles embedded in fullerene C₇₀ matrix) is synthesized by thermal co-deposition method. Thermal stability of Ag-C₇₀ nanocomposite is investigated by annealing the nanocomposite thin film at different temperatures from 80 to 350 °C for 30 min. Optical and structural properties of nanocomposite thin film with respect to high temperature are studied by UV-visible spectroscopy and x-ray diffraction, respectively. Transmission electron microscopy is performed to observe the temperature-dependent size evolution of Ag nanoparticles in fullerene C₇₀ matrix. A large growth of Ag nanoparticles is observed with temperature especially above 200 °C due to enhanced diffusion of Ag in fullerene C₇₀ at higher temperature and Ostwald ripening. The properties of metal-fullerene nanocomposite is not significantly affected up to a temperature of 150 °C. With a further increase in temperature, a major blue shift of ~?33 nm in SPR wavelength is seen at a temperature of 300 °C due to the thermal induced structural transformation of fullerene C₇₀ matrix into amorphous carbon. A very large-sized Ag nanoparticle with a wide size distribution varying from 27.8 ± 0.6 to 330.0 ± 4.5 nm is seen at 350 °C and due to which, a red shift of ~?16 nm is obtained at this temperature. This study throws light on the thermal stability of the devices based on metal-fullerene bi-functional nanocomposite.     

Molecular Characterization of Monochloroacetate-Degrading Arthrobacter sp. Strain D2 Isolated from Universiti Teknologi Malaysia Agricultural Area

Arthrobacter sp. strains D2 and D3 and Labrys sp. strain D1 capable of degrading 20 mM monochloroacetic acid (MCA) were isolated from soil contaminated with herbicides and pesticides. All three isolates were able to grow on MCA as the sole source of carbon and energy with concomitant chloride ion release in the growth medium (19 mM). Strains D2 and D3 (cells doubling time 7 ± 0.3 h) grew four times faster than D1 (26 ± 0.1 h). Strain D2 was then further investigated and could also grow in 10 mM of monobromoacetic acid (MBA), 2,2-dichloropropionic acid (2,2DCP), d,l-2-chloropropionic acid (D,L2CP), l-2-chloropropionic acid (L-2CP), d-2-chloropropionic acid (D-2CP), and glycolate as the sole sources of carbon and energy. Dehalogenase gene amplification using group I primers revealed a 410-bp polymerase chain reaction (PCR) product, but there was none using group II primers. The partial amino acid sequence analysis of group I DehD2 dehalogenase showed at least 32% identity to the corresponding regions of DehE, DhlIV, DehI, and D,L-DEX, with key amino acid residues Ser188, Ala187, and Asp189. These amino acid residues were involved in substrate binding and catalysis and were conserved in the partial amino acid sequence.     

Comparative analysis of direct plant regeneration from immature leaf whorl and floral explants for three elite US sugarcane (Saccharum spp. hybrids) genotypes

Sugarcane (Saccharum spp. hybrids) is an important commodity field crop in tropical and subtropical countries providing sugar and biofuel feedstock and occupying a critical and strategic position in the global economy. This study was conducted to evaluate, compare, and optimize a rapid direct regeneration tissue culture system from immature leaf whorl and pre-emergent floral explants for three elite US sugarcane genotypes: CP84-1198, CP88-1762, and CP89-2143. Direct regeneration of adventitious shoot buds from the immature leaf roll explants and subsequent elongation and rooting of shoot buds was successfully obtained on modified Murashige and Skoog salt medium supplemented with 5 mg l^–1 α-naphthaleneacetic acid and 0.5 mg l^?1 kinetin. Significant genotype-specific differences in the morphogenetic potential of leaf roll explants were discernible with the explant developmental stage (explant position along the leaf roll axis) and orientation during in vitro culture. The highest number of shoots was regenerated from CP88-1762, followed by CP89-2143 and CP84-1198 from explants closest to the meristem that were oriented horizontally (CP88-1762) or vertically (CP89-2143 and CP84-1198) on the culture medium. Immature inflorescence-derived explants from all three genotypes when cultured on the above medium for 2 wk rapidly produced shoots, followed by rooting on medium supplemented with 4 mg l^?1 indole-3-butyric acid. The regeneration protocols yielded robust rooted plantlets from immature leaf roll explants within 4 to 6 wk, which were readily acclimatized under greenhouse conditions.     

A comparison of head-out mist bathing,with or without facial fanning,with head-out half-body low-water level bathing in humans—a pilot study

To reduce the risks of Japanese-style bathing, half-body bathing (HBLB) has been recommended in Japan, but discomfort due to the cold environment in winter prevents its widespread adoption. The development of the mist sauna, which causes a gradual core temperature rise with sufficient thermal comfort, has reduced the demerits of HBLB. We examined head-out 42 °C mist bathing with 38 °C HBLB up to the navel to see if it could improve thermal comfort without detracting from the merits of HBLB, with and without the effects of facial fanning (FF). The subjects were seven healthy males aged 22–25 years. The following bathing styles were provided: (1) HBLB—head-out half-body low bathing of 38 °C up to the navel (20 min); (2) HOMB—head-out mist bathing of 42 °C and HBLB of 38 °C (20 min); and (3) HOMBFF—HOMB with FF (20 min). HOMB raised the core temperature gradually. HOMBFF suppressed the core temperature rise in a similar fashion to HOMB. Increases in blood pressure and heart rate usually observed in Japanese traditional-style bathing were less marked in HOMBs with no significant difference with and without FF. The greatest body weight loss was observed after Japanese traditional-style bathing, with only one-third of this amount lost after mist bathing, and one-sixth after HBLB. HOMB increased thermal sensation, and FF also enhanced post-bathing invigoration. We conclude that HOMB reduces the risks of Japanese traditional style bathing by mitigating marked changes in the core temperature and hemodynamics, and FF provides thermal comfort and invigoration.     

On the biology and thermal developmental requirements of the cotton mealybug,Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) in Egypt

This study evaluated the thermal requirements for development of the cotton mealybug Phenacoccus solenopsis depending on different biological parameters on Okra leaves Abelmoschus esculentusat under two constant temperatures (20 and 30 °C) at (RH 65%, 12:12 h. light/dark). The effect of temperature on eggs was ineffective since it hatched shortly to first nymphal instars after deposition. While the tested temperature caused significant effects on nymphal durations, pupation rate (pre-male stage), females emergence %, pre-oviposition, longevity, post-oviposition periods and fecundity in females (egg deposition, ovisacs numbers and hatchability %). The thermal constant and developmental zero were calculated to be 7.29 °C and 79.9 degree-days (DDs) for eggs, 11.67 °C and 272.9 DDs for nymphal stages, 11.06 °C and 46.4 DDs for males and then 3.31 °C and 554.1 DDs for females, respectively. The duration of the life cycle was 65.6 ± 10.36 days at 20 °C; this was shortened to 35.51 ± 1.12 days at 30 °C. The thermal requirements to complete the insect development for one generation was 8.2 °C for the developmental zero and 774.1 DDs for the thermal constant. Based on the thermal requirements values, the average life cycle duration from January to December 2016 was 61.78 days and the number of annual generations was 7.143 when the average annual temperature was 23.29 °C.     

Nutritional value of 15 corn gluten meals for growing pigs: chemical composition,energy content and amino acid digestibility

The objectives of this study were to determine the chemical composition, energy content and amino acid digestibility for corn gluten meals (CGM) and to develop prediction equations for estimating energy content and amino acid digestibility for growing pigs based on the chemical characteristics of these meals. The 15 CGM tested were obtained from seven Chinese companies. Experiment 1 was conducted to determine the digestible (DE) and metabolisable energy (ME) of the 15 CGM. The 18 growing barrows (38 ± 4 kg) were assigned to three 6 × 6 Latin square designs. The 15 CGM test diets were formulated to contain 19.20% CGM, which replaced 20% of the energy supplied by corn and crystalline amino acid in the basal diet. Experiment 2 was conducted to determine the apparent (AID) and standardised (SID) ileal digestibility of the crude protein (CP) and amino acids in the 15 CGM using chromic oxide as an inert marker. The 18 growing barrows (25 ± 2 kg) fitted with a simple T-cannula were assigned to three 6 × 6 Latin square designs. The 15 test diets contained 35% of one of the 15 CGM as the sole source of amino acids in the diet. The results showed a considerable variation in the chemical composition of CGM within and among plants. On dry matter basis, the DE and ME content of the CGM ranged from 18.8 to 21.0 MJ/kg and from 18.0 to 19.9 MJ/kg, respectively. There were no significant differences in the AID and SID for CP, arginine, lysine, glycine and proline among the 15 CGM, however, for all the other amino acids, significant differences were found for their AID and SID. With R ² values exceeding 0.50, the DE of CGM can be predicted accurately from CP and fibre content and ME from starch and fibre content. Suitable prediction equations for SID of methionine were also developed.     

Spatial and temporal dynamics of diffusive methane emissions in the Okavango Delta,northern Botswana,Africa

Global warming is associated with the continued increase in the atmospheric concentrations of greenhouse gases; carbon dioxide, methane (CH₄) and nitrous oxide. Wetlands constitute the largest single natural source of atmospheric CH₄ in the world contributing between 100 and 231 Tg year^?1 to the total budget of 503–610 Tg year^?1, approximately 60 % of which is emitted from tropical wetlands. We conducted diffusive CH₄ emission measurements using static chambers in river channels, floodplains and lagoons in permanent and seasonal swamps in the Okavango Delta, Botswana. Diffusive CH₄ emission rates varied between 0.24 and 293 mg CH₄ m^?2 h^?1, with a mean (±SE) emission of 23.2 ± 2.2 mg CH₄ m^?2 h^?1 or 558 ± 53 mg CH₄ m^?2 day^?1. These emission rates lie within the range reported for other tropical wetlands. The emission rates were significantly higher (P < 0.007) in permanent than in seasonal swamps. River channels exhibited the highest average fluxes at 31.3 ± 5.4 mg CH₄ m^?2 h^?1 than in floodplains (20.4 ± 2.5 mg CH₄ m^?2 h^?1) and lagoons (16.9 ± 2.6 mg CH₄ m^?2 h^?1). Diffusive CH₄ emissions in the Delta were probably regulated by temperature since emissions were highest (20–300 mg CH₄ m^?2 h^?1) and lowest (0.2–3.0 mg m^?2 h^?1) during the warmer-rainy and cooler winter seasons, respectively. Surface water temperatures between December 2010 and January 2012 varied from 15.3 °C in winter to 33 °C in summer. Assuming mean inundation of 9,000 km², the Delta’s annual diffusive emission was estimated at 1.8 ± 0.2 Tg, accounting for 2.8 ± 0.3 % of the total CH₄ emission from global tropical wetlands.