14C Content Research Articles

The effects of diet and beauty products on the uptake and storage of 14C in hair and nails: ramifications for the application of bomb pulse dating to forensic anthropological casework

Radiocarbon dating is a useful tool in the examination of unknown human remains. Recent studies have shown that the analysis of hair and nail samples can provide a highly accurate estimation of the year of death (YOD). However, little research has examined factors that may influence the uptake and storage of 14C in these tissues, such as diet, or the use of beauty products. This study measured the level of 14C in human hair and nail samples collected from living individuals to determine whether diet, and the use of hair dye or nail polish, has a significant impact on the estimation of YOD. The results of this study showed that diet did not appear to impact the radiocarbon content in human hair and nail, and thus should not be considered a limitation when analysing samples obtained from unidentified human remains. The use of nail polish, and in the majority of cases, hair dye, did not significantly impact the 14C concentration in nails and hair. While the results of this study are preliminary, they suggest that in most cases, both hair and nail can be successfully analysed using radiocarbon dating to estimate an individual’s YOD. However, best practice should involve the analysis of multiple tissue types, to minimise any error that may be introduced as a result of the decedent’s use of beauty products.

Quality Characteristics of Black Soldier Flies Produced by Different Substrates

Black soldier fly (BSF; Hermetia illucens) has a high capacity for amino acids and fatty acid accumulation. This study was conducted to assess the effectiveness of tofu by-products, food waste, and vegetables for BSF growth and conversion efficiency. BSFs under tofu by-product treatments showed the greatest weight at d 12 and the harvest period. Moreover, BSF larval weight was greater in the food waste treatment compared with the vegetable treatment at d 12 and harvest. The larva yield result was greater in the vegetable treatment compared with the tofu by-product. The bioconversion rate was higher in the tofu by-product treatment compared with the food waste and vegetable treatments. The protein conversion rate and lipid conversion rate were the highest in the vegetable treatment. The protein yield and lipid yield were greatest in the tofu by-product treatment. The lauric acid content was increased in BSFs fed tofu by-products compared with the food waste treatment. The concentration of C16:1 was the highest in the tofu by-product treatment. The content of oleic acid and α-linolenic acid was higher in BSFs fed tofu by-products compared with the vegetable treatment. In conclusion, the tofu by-products show benefits for larval growth and nutrient accumulation, which can improve larval quality for livestock feed ingredients.

TWO NEW MILLENNIUM-LONG TREE-RING OXYGEN ISOTOPE CHRONOLOGIES (2349–1009 BCE AND 1412–466 BCE) FROM JAPAN

ABSTRACTWe present two new millennium-long tree-ring oxygen isotope chronologies for central and northern Japan, based on 9693 annually resolved measurements of tree-ring oxygen isotopes from 39 unearthed samples consisting mainly of Japanese cedar (Cryptomeria japonica). These chronologies were developed through cross-dating of tree-ring widths and δ18O data from multiple samples covering the periods 2349–1009 BCE (1341 yr) and 1412–466 BCE (947 yr) for central and northern Japan, respectively. In combination with our published chronology for central Japan, the tree-ring δ18O dataset currently available covers the past 4354 yr (2349 BCE to 2005 CE), which represents the longest annually resolved tree-ring δ18O dataset for Asia. Furthermore, the high-resolution temporal record of 14C contents independently developed by Sakurai et al. (2020) was reproduced by our 14C measurements of earlywood and latewood in annual rings for the period 667–660 BCE.

The Influence of Cold-Pressed Linseed Cake Supplementation on Fatty-Acid Profile and Fat-Soluble Vitamins of Cows' Milk in an Organic Production System.

The aim of the study was to determine the effect of linseed cake supplementation during the winter period as a factor influencing the level of some bioactive components (milk composition, fatty-acid profile, and fat-soluble vitamins) in the milk fat fraction in cows kept on an organic farm. Forty multiparous (second and third lactation) Holstein-Friesian cows were selected that had 81 ± 12 days in milk and produced 15.08 ± 1.20 kg of milk/day. Two groups were created for the experiment: control (CTL; n = 20) and experimental (LC; n = 20). The experiment was divided into two periods: an initial period lasting 7 days in which the experimental group was habituated to the new supplement in their diet; the proper experimental phase, lasting 6 weeks, in which the cows in the experimental group received an individual daily dose of linseed cake (300 g/day/cow). Linseed cake supplementation had a positive impact on the levels of bioactive components (fatty-acid profile and fat-soluble vitamins) in the milk fat fraction. At the end of the trial, the concentration of C18:2 cis9 trans11, C18:1 trans11, α-retinol, α-tocopherol, and total antioxidant status increased 1.59-, 1.94-, 3.12-, 3.38-, and 3.09-fold, respectively, relative to the control levels. The use of linseed cake in winter on organic farms makes it possible to increase the antioxidant potential of milk, thereby eliminating the disparity in the quality of milk from the summer season compared to the winter season.

153 Meat Quality of Barbados Blackbelly and St. Croix Hair Sheep Lambs Rendered Short Scrotum or Castrated at Weaning

Abstract This study evaluated meat quality parameters of short scrotum and castrated Barbados Blackbelly (BB; n = 16) and St. Croix (STX; n = 15) hair sheep ram lambs. Ram lambs born in April (n = 21) and December (n = 10) were rendered short scrotum (SS; n = 17) or castrated (CA; n = 14) using elastrator bands at weaning (63 days of age). Following a transition period of 2 months in a dry lot, ram lambs co-grazed with ewe lambs in a rotational pasture system and were provided soy hull at 3% BW daily. At target weights of app. 40 kg lambs were slaughtered and loin cuts from individual carcasses were collected for meat quality analysis. Data from the two lambing groups were pooled and analyzed as a completely randomized design with a 2 x 2 factorial treatment arrangement for breed (BB or STX) and sex class (SS or CA). The CIE L* (lightness), a* (redness), and b* (yellowness) values of loin cuts were not significantly influenced by breed or sex class. The longissimus muscle (LM) in loin cuts from CA lambs had a greater (P < 0.0001) fat content (3.73 vs 2.55 ± 0.155%) and tended (P = 0.06) to have a decreased moisture content (69.63 vs 70.75 ± 0.413%) than that from SS lambs. Neither breed nor sex class significantly affected the myoglobin content, percent metmyoglobin and thiobarbituric acid reactive substances (TBARS) values of LM from lamb cuts. Cuts from SS lambs had greater (P < 0.0001) shear force values (3.22 vs 2.64 ± 0.093 kg) than those from CA lambs. However, the cooking loss of loin cuts was not significantly influenced by breed or sex class. The fatty acid profiles of LM from experimental lambs were significantly influenced by breed and sex class. Compared with BB, STX had greater (P < 0.05) concentrations of myristic (C14:0;.38 vs.23%), palmitic (C16:0; 20.15 vs8.98%) and oleic (C18:1n9; 45.01 vs 42.81%), but less than (P < 0.05) concentrations of stearic (C18:0;7.29 vs9.33%) and linoleic (C18:2n6; 6.14 vs 7.47%) acids in LM. Furthermore, the LM from SS lambs had greater (P < 0.05) concentrations of C18:2n6 (8.09 vs 5.51%) and arachidonic (C20:4n6, 2.04 vs.40%), but lless than (P < 0.05) concentrations of C16:0 (19.07 vs 20.06%) and C18:1n9 (41.57 vs 46.24%) acids than that from CA lambs. Data suggest that meat quality parameters were more greatly influenced by sex class than breed when landrace hair sheep lambs were slaughtered at a target weight. Loin cuts from SS lambs were leaner, but less tender than those of CA lambs, and also differed in their fatty acid profiles. Hence meat quality will be impacted by the choice of rendering male lambs sterile.

Effect of postruminal supply of linseed oil in dairy cows: 2. Milk fatty acid profile and oxidative stability.

Our objective was to study the effect of increasing postruminal supply of linseed oil (L-oil), as a source of cis-9, cis-12, cis-15 18:3, on milk fatty acid profile and to assess the resulting impact on the development of volatile degradation products during the storage of homogenized milk. Five Holstein dairy cows fitted with a rumen cannula were randomly distributed in a 5 × 5 Latin square design. Abomasal infusion of L-oil was performed at the rate of 0, 75, 150, 300, and 600 ml/d during periods of 14 d. The concentration of cis-9, cis-12, cis-15 18:3 in milk fat increased linearly with L-oil dose. Concentrations of primary (conjugated diene and triene hydroperoxides) and secondary oxidation products (1-octen-3-one, propanal, hexanal, trans-2 + cis-3-hexenals, cis-4-heptenal, trans-2, cis-6-nonadienal trans-2, trans-4-nonadienal) increased during 11 d of storage at 4°C of homogenized milk under fluorescent light. The magnitude of the increase (difference between final and initial measurements) was linearly greater for all nine lipid oxidation products evaluated in response to increasing level of infusion. Results of the current experiment have shown that milk enriched in cis-9, cis-12, cis-15 18:3 via postruminal supply of L-oil is highly prone to oxidative degradation. This low oxidative stability, exposed under controlled experimental conditions, would represent a major obstacle to those who aim to market milk enriched in polyunsaturated fatty acids.

Effect of dietary Agriophyllum squarrosum on average daily gain, meat quality and muscle fatty acids in growing Tan lambs

The herb A. squarrosum is reputed to possess medicinal properties for humans, and has the potential to be a feed resource for livestock. We hypothesized that this herb would improve the meat quality of lambs. To test this hypothesis, 24 Tan ewe-lambs (27.7 ± 0.45 kg) were offered diets containing 0 (CON), 100 (AS100), 200 (AS200) and 300 (AS300) g A. squarrosum/kg DM, and average daily gain, carcass traits, blood metabolites, meat quality and fatty acid profiles were determined. Drip loss % and cooking loss % decreased with the AS100 and AS200 diets (P < 0.05). Dietary A. squarrosum reduced muscle fiber area and diameter and increased density of the meat (P < 0.05), which indicated that the meat was more tender. The concentrations of C10:0 and C18:1n-9 t were 1ower and of C17:0 and C18:3n-3 were greater in the AS200 and AS300 treatments than CON (P < 0.05). Our results suggest that feeding lambs up to 200 g/kg DM of A. squarrosum can increase the water-holding capacity and L* value of meat without compromising growth. Further research is needed to determine the optimal level.

Fatty Acids Profiling, Lipid Quality Indices and Antioxidant Properties of Some Small Indigenous Fishes of Manipur, India under Indo-Burma Biodiversity Hotspot Region

Aims: The aim of the study is to access the nutritional qualities viz. fatty acids profile, lipid quality indices and antioxidant properties of fish oil. The present study will provide the information on the fulfillment of various nutritional qualities of small fishes.&#x0D; Study Design: The study was carried out during the month of October, 2017 to February, 2018 in fishery laboratory, department of Life Sciences, Manipur University, India.&#x0D; Methodology: The extraction and analysis of fatty acids were carried out following the method of Metcalfe et al. 1966. The fatty acids are identified searching in the NIST database using mass spectral search program. For antioxidant property the extract was analyzed using DPPH assay following the method described by Koleva et al. 2002. Data were analyzed using SPSS package (Version 17.0).&#x0D; Results: The most abundant fatty acid (SFA) is palmitic acid (C16:0) which is followed by Stearic acid (C18:0) and undecylic acid (C11:0). The concentration of C16:0 was in the ranged of 14.67% to 27.96% which was highest in H. myitkyinae and lowest in G. giuris. Among the monounsaturated fatty acid (MUFA) Oleic acid (C18:1n9) was the most abundant fatty acid which is followed by Vaccenic acid (C18:1n11) and heptadecanoic acid (C17:1) respectively. Docosahexanoic acid (DHA) and Ecosapentanoic acid (EPA) are the predominant n3 fatty acids in all the fish studied. The index of atherogenicity (AI), index of thrombogenicity (TI), Hypocholesterolemic/ Hypercholesterolemic (HH) fatty acid ratio and Flesh lipid quality (FLQ) was in the ranged of 0.79% to 1.10%, 0.13% to 0.67%, 0.53%- 2.53% and 1.90% to 7.72% respectively. The highest antioxidant property was found in P. chola (8.69 µg/ml) and the lowest was observed T. burmanicus (46.83 µg/ml).&#x0D; Conclusion: From the above analysis Small indigenous freshwater fishes (SIFFs) contained good lipid which provide enormous amount of PUFA and MUFA especially DHA and EPA contribute to various health related benefit. The scavenging activities of antioxidant properties of the SIFFs are also found to be considerable. Thus it can be indicates that these small fishes have good nutritional quality and can bring many benefits to human health.

Refractory Dissolved Organic Matter has Similar Chemical Characteristics but Different Radiocarbon Signatures With Depth in the Marine Water Column

AbstractThe &gt;5,000‐year radiocarbon age (14C‐age) of much of the 630 ± 30 Pg C oceanic dissolved organic carbon (DOC) reservoir remains an enigma in the marine carbon cycle. The fact that DOC is significantly older than dissolved inorganic carbon at every depth in the ocean forms the basis of our current framing of the marine DOC cycle, where some component persists over multiple cycles of ocean mixing. As a result, 14C‐depleted, aged DOC is hypothesized to be present as a uniform reservoir with a constant 14C signature and concentration throughout the water column. However, key requirements of this model, including direct observations of DOC with similar 14C signatures in the surface and deep ocean, have never been met. Despite decades of research, the distribution of Δ14C values in marine DOC remains a mystery. Here, we applied a thermal fractionation method to compare operationally defined refractory DOC (RDOC) from different depths in the North Pacific Ocean. We found that RDOC shares chemical characteristics (as recorded by OC bond strength) throughout the water column but does not share the same 14C signature. Our results support one part of the current paradigm—that RDOC is comprised of structurally related components throughout the ocean that form a “background” reservoir. However, in contrast to the current paradigm, our results are consistent with a vertical concentration gradient and a vertical and inter‐ocean Δ14C gradient for RDOC. The observed Δ14C gradient is compatible with the potential addition of pre‐aged DOC to the upper ocean.

Long-range transport and deposition on the Arctic snowpack of nuclear contaminated particulate matter

The primary environmental concern related to nuclear power is the production of radioactive waste hazardous to humans and the environment. The main scientific and technological problems to address this are related to the storage and disposal of the nuclear waste and monitoring the dispersion of radioactive species into the environment. In this work, we determined an anomalously high 14C activity, well above the modern natural background, on surface and seasonal snow sampled in early May 2019 on glaciers in the Hornsund fjord area (Svalbard). Due to the lack of local sources, the high snow concentrations of 14C suggest long-range atmospheric transport of nuclear waste particles from lower latitudes, where nuclear power plants and treatment stations are located. The analysis of the synoptic and local meteorological data allowed us to associate the long-range transport of this anomalous 14C concentration to an intrusion event of a warm and humid air mass that likely brought pollutants from Central Europe to the Arctic in late April 2019. Elemental and organic carbon, trace element concentration data, and scanning electron microscopy morphological analysis were performed on the same snow samples to better constrain the transport process that might have led to the high 14C radionuclide concentrations in Svalbard. In particular, the highest 14C values found in the snowpack (> 200 percent of Modern Carbon, pMC) were associated with the lowest OC/EC ratios (< 4), an indication of an anthropogenic industrial source, and with the presence of spherical particles rich in iron, zirconium, and titanium which, altogether, suggest an origin related to nuclear waste reprocessing plants. This study highlights the role of long-range transport in exposing Arctic environments to human pollution. Given that the frequency and intensity of these atmospheric warming events are predicted to increase due to ongoing climate change, improving our knowledge of their possible impact to Arctic pollution is becoming urgent.

A WIGGLE-MATCHED 297-YR TREE-RING OXYGEN ISOTOPE RECORD FROM THAILAND: INVESTIGATING THE 14C OFFSET INDUCED BY AIR MASS TRANSPORT FROM THE INDIAN OCEAN

ABSTRACTRegional offsets from Northern Hemisphere radiocarbon (14C) calibration curves are widely recognized for monsoon Asia and often hinder accurate 14C dating. In this paper, we explore the possible linkage between summer monsoon intensity and 14C offsets using tree-ring δ18O and 14C data from Thailand. We developed a 297-yr floating tree-ring δ18O chronology comprising seven teak log-coffin samples from the Ban Rai rock shelter site, northwestern Thailand. The outermost ring of our chronology was estimated to date from 358–383 CE, within a 95.4% (2σ) probability range, based on a total of 10 14C measurements that were wiggle-matched against a mixed calibration curve evenly weighted from the IntCal20 and SHCal20 curves. Backward trajectory analysis showed that an intensified (weakened) summer monsoon detected in a modern tree-ring δ18O chronology was most likely to be induced by increased (decreased) air mass transport from the tropical Indian Ocean, which is an area of intense upwelling where the 14C concentration is lower than the atmospheric 14C level. However, partly because of the limited sample size and dating uncertainty, the direct linkage between the tree-ring δ18O series and 14C records obtained from our teak log-coffin samples could not be statistically verified.

Black Soldier Fly Larva Fat in Broiler Chicken Diets Affects Breast Meat Quality

This study aimed to evaluate the dose-dependent effect of black soldier fly (BFL) larvae fat inclusion in broiler chicken diets on breast meat quality. Four hundred 1-day-old male birds (Ross 308) were assigned to the following four treatments (10 replicates with 10 birds each): HI0, a basal diet without dietary fat inclusion, and HI03, HI06, and HI09, basal diets enriched with 30 g/kg, 60 g/kg, and 90 g/kg of BSF larvae fat, respectively. Principal component analysis showed noticeable differentiation between the selected plant, animal, and insect-origin dietary fats. The BSF fat exhibits a strong relationship with saturated fatty acids (SFAs), resulting in a high concentration of C12:0 and C14:0. The fatty acid (FA) profile in breast muscle obtained from broilers fed diets with increasing insect fat inclusion showed a significant linear effect in terms of C12:0, C15:0, C18:2, C18:3n6, and total FAs. The proportion of dietary insect fat had a quadratic effect on meat color. The water-holding capacity indices have stayed consistent with the meat color changes. Throughout the experiment, favorable growth performance results were noticed in HI06. The present study confirmed that BSF larvae fat negatively affects the n3 level in meat. However, the physicochemical indices related to consumer acceptance were not altered to negatively limit their final decision, even when a relatively high inclusion of insect fat was used.

Reinterpreting radiocarbon records in bamboo corals – New insights from the tropical North Atlantic

Deep-sea bamboo corals (family Isididae) have been used as archives for reconstructing changes in the past ocean. However, uncertainties remain regarding the interpretation of geochemical signals from their organic nodes, specifically the water depth of the signals recorded by the coral. Here we explore this question by measuring radiocarbon (14C) and nitrogen (15N) isotopic compositions of the organic nodes in six bamboo corals collected from the central and eastern tropical Atlantic between 700 m and 2000 m water depth. By comparing coral 14C to measured seawater data, regional shallow-water coral records and climate-model outputs, we find contrasting results between the two regions. Our bamboo coral 14C results from the eastern tropical Atlantic support previous studies that suggest organic node carbon is sourced primarily from the mixed layer of the ocean. By contrast, the 14C of bamboo coral organic nodes from the oligotrophic central Atlantic better correlates with the 14C content of the subsurface deep chlorophyll maximum layer rather than the surface mixed layer. Combined with nitrogen isotope data, this observation suggests that sinking and/or ambient zooplankton feeding on phytoplankton from the deep chlorophyll maximum layer can contribute a significant proportion of the diet of bamboo corals. These results suggest that the carbon source for bamboo corals organic nodes may not always reside in the mixed layer, especially in oligotrophic regions, which has implications for 14C-based age model development in bamboo corals.

Impact of natural betaine supplementation on rumen fermentation and productive performance of lactating Damascus goats

Two natural betaine sources; dehydrated condensed molasses fermentation solubles (Bet1) and Betafin®, a commercial anhydrous betaine extracted from sugar beet molasses and vinasses (Bet2); were used to investigate their impact on rumen fermentation parameters and lactation performance of lactating goats. Thirty-three lactating Damascus goats, with an average weight of 37 ± 0.7 kg and their age ranged from 22 to 30 months (2nd and 3rd lactation season), were divided into three groups, each group contained 11 animals. The control group (CON) was fed ration without betaine. While the other experimental groups were fed a control ration supplemented either with Bet1 or Bet2 to provide a 4 g betaine/kg diet. Results confirmed that betaine supplementation improved nutrient digestibility and nutritive value, and increased milk production and milk fat contents with both Bet1 and Bet2. Significant increases in concentration of ruminal acetate were observed in betaine-supplemented groups. Goats fed dietary betaine non-significantly recorded higher concentrations of short and medium-chain fatty acids (C4:0 to C12:0), and significant lower concentrations of C14:0 and C16:0 in milk. Also, both Bet1 and Bet2 non-significantly decreased the blood concentrations of cholesterol and triglycerides. Therefore, it could be concluded that betaine can improve the lactation performance of lactating goats and produce healthy milk with beneficial characteristics.

Source apportionment of black carbon aerosols by isotopes (14C and 13C) and Bayesian modeling from two remote islands in east Asian outflow region

We report the results of source apportionment of combustion-derived black carbon (BC), in PM2.5 aerosols collected from the East Asian continental outflow region at two islands; Okinawa and Fukue during the period from October 2009 to May 2010. The 14C contents of BC from Okinawa (Cape Hedo) and Fukue islands (Fukue) varied from 24.4 to 34.2 pMC and from 18.1 to 43.0 pMC, respectively. Source apportionment of BC was conducted by using a simple 14C mass balance model and a dual-isotope Bayesian Markov chain Monte Carlo model. Biomass combustion contributions (e.g., wood fuel and crop residues) were 23–31 % (mean 27 ± 3 %) at Cape Hedo and 15–38 % (mean 27 ± 12 %) at Fukue. Both sites were equally affected by biomass combustion, whose levels are similar to those observed in the hotspot regions (megacities) in China. Fossil fuel contributions (e.g., oil, gasoline, and diesel) were 69–77 % (mean 74 ± 3 %) with 2–69 % from coal and 3–76 % from liquid fossil at Cape Hedo, and 55–85 % (mean 73 ± 12 %) at Fukue with 3 % from coal and 53–56 % from liquid fuel for the early winter. Those variations for both sites showed significantly different source region-specific trends and this trend was also consistent with the results of the air mass trajectory analysis with a higher contribution of coal-BC from North China including Beijing, and East China including Shanghai. In spring, we found a higher contribution of liquid fossil fuel combustion (e.g., traffic) over the East China Sea, including Pacific air masses, suggesting that the possible contribution of ship emissions was relatively high. Although our results for isotopes-based source apportionment of BC are preliminary, these findings suggest that long-term monitoring of BC aerosols, even in remote sites of Asian outflows, and source-specific descriptions of BC are important to improve climate models. We also recommend further measurements for implementing regionally tailored mitigation.

Monthly measurements of water dissolved inorganic radiocarbon in Lake Kawaguchi for three years indicating seasonal precipitation-groundwater variations

Understanding groundwater dynamics is important for projecting water resources of the Lake Kawaguchi, however, the difficulty of observation and the limited number of geochemical tracers are a problem. In this study, we investigated 14C concentration (Δ14C) of lake water for three years and employed a 14C box model to estimate the groundwater contribution. Seasonal variations of Δ14C were also observed in both 2019 and 2020, confirming that Δ14C in Lake Kawaguchi decreases from summer to fall and increases during winter. Heavy precipitation exceeding 300 mm in a few days because of tropical cyclon HAGIBIS (Typhoon#19) significantly increased Δ14C in the lake for one month and it could caused by temporal changes in the surface water pathway. The 14C box model demonstrated that 14C could semiquantitatively evaluate the groundwater flow in the lake. It is needed to add quantative evaluations inflow from rivers and other factors to understand of groundwater dynamics.

Testing the potential of Serpulidae tubes as an indicator of past relative sea-level collected from shored wave dissipating blocks along the Pacific and Japan sea coast of northeastern Japan

Relative sea-levels (RSL) in the past can be used to understand crustal movements, as paleo-shoreline elevations can be modified by seismic activities [1]. To assess short-term crustal movements, reliable RSL proxies are key in age determination to derive precise tectonic activities. The Tohoku region in northern Japan has complex oceanographic setting since two currents, cold Oyashio and warm Kuroshio being merged in the region. Here, we assessed the potential of Hydroides ezoensis (HE), as a new proxy of RSL. The 14C concentrations of HE collected in the Tohoku region were measured and compared with previous studies that reported radiocarbon values of the surface ocean. Results showed HE possesses summer surface 14C. This suggests that HE is suitable to be used as a reliable RSL proxy that can reliably provide age information without having influences from radiocarbon depleted Oyashio. Thus, HE could be used as a reliable proxy to understand paleo-RSL.

Radiocarbon and wood anatomy as complementary tools for generating tree-ring records in Bolivia.

The science of tropical dendrochronology is now emerging in regions where tree-ring dating had previously not been considered possible. Here, we combine wood anatomical microsectioning techniques and radiocarbon analysis to produce the first tree-ring chronology with verified annual periodicity for a new dendrochronological species, Neltuma alba (commonly known as "algarrobo blanco") in the tropical Andes of Bolivia. First, we generated a preliminary chronology composed of six trees using traditional dendrochronological methods (i.e., cross-dating). We then measured the 14C content on nine selected tree rings from two samples and compared them with the Southern Hemisphere (SH) atmospheric 14C curves, covering the period of the bomb 14C peak. We find consistent offsets of 5 and 12 years, respectively, in the calendar dates initially assigned, indicating that several tree rings were missing in the sequence. In order to identify the tree-ring boundaries of the unidentified rings we investigated further by analyzing stem wood microsections to examine anatomical characteristics. These anatomical microsections revealed the presence of very narrow terminal parenchyma defining several tree-ring boundaries within the sapwood, which was not visible in sanded samples under a stereomicroscope. Such newly identified tree rings were consistent with the offsets shown by the radiocarbon analysis and allowed us to correct the calendar dates of the initial chronology. Additional radiocarbon measurements over a new batch of rings of the corrected dated samples resulted in a perfect match between the dendrochronological calendar years and the 14C dating, which is based on good agreement between the tree-ring 14C content and the SH 14C curves. Correlations with prior season precipitation and temperature reveal a strong legacy effect of climate conditions prior to the current Neltuma alba growing season. Overall, our study highlights much potential to complement traditional dendrochronology in tree species with challenging tree-ring boundaries with wood anatomical methods and 14C analyses. Taken together, these approaches confirm that Neltuma alba can be accurately dated and thereby used in climatic and ecological studies in tropical and subtropical South America.

Compositional characteristics and indication of n-fatty acids in alpine meadow plants and soils

AimTo explore the distributions and indication of n-fatty acids in the plants and soils from alpine meadow, and how n-fatty acids in plants and soils are associated. MethodsThe plant (grass, herb, and shrub) and soil samples were collected from alpine meadow in the Qinghai-Tibet Plateau, and the compositional characteristics of n-fatty acids were analyzed using GC-MS. Results and conclusionn-Fatty acids ranging from C6 to C28 were identified, C16 was the most abundant fatty acid in most plants, which contributed between 39.1% and 74.2% to total n-fatty acids; the most abundant fatty acid in soils was C15, which contributed between 72.1% and 89.1% to total n-fatty acid. The total n-fatty acid content of Artemisia hedinii and the long chain n-fatty acid content of Ajuga lupulina were the highest, while the total and long chain n-fatty acid content of Saxifraga tangutica were the lowest. The contents of C20, C22, C24 and C26 in indicative plants of degradation and typical dominant plants (Festuca sinensis, Elymus nutans, Poa crymophila, Kobresia humulis, Kobresia pygmaea) were higher than other long chain n-fatty acids (C ≥ 20). The n-fatty acids content of the plants in degraded alpine meadow were higher than that in non-degraded alpine meadow except C6, C23, C25 and C27. The total n-fatty acids content of plants and soils in degraded alpine meadow were higher than that of non-degraded meadow. The n-fatty acids content in soils were decreased with the increasing depth of sampling except C15. The positive correlation of long chain n-fatty acids content in soils and plants was strongly significant (p < 0.001, R2 = 0.926). The compositional characteristics of n-fatty acids in plants and soils were similar. Therefore, the source of the long chain n-fatty acids in the soil might be deduced from native vegetation.

Prospects for Biodiesel Production from Emerging Algal Resource: Process Optimization and Characterization of Biodiesel Properties

The present work focuses on the optimization of the energy conversion process and the use of algal resources for biodiesel production with ultrasound and microwave techniques in Oedogonium, Oscillatoria, Ulothrix, Chlorella, Cladophora, and Spirogyra for the first time. The fuel properties are investigated to optimize the efficiency of the newly emerging algal energy feedstock. The study indicates that the optimized microwave technique improves the lipid extraction efficiency in Oedogonium, Oscillatoria, Ulothrix, Chlorella, Cladophora, and Spirogyra (38.5, 34, 55, 48, 40, and 33%, respectively). Moreover, the ultrasonic technique was also effective in extracting more lipids from Oedogonium sp., Oscillatoria sp., Ulothrix sp., Chlorella, Cladophora sp., and Spirogyra sp. (32, 21, 51, 40, and 36%, respectively) than from controls, using an ultra-sonication power of 80 kHz with an 8-min extraction time. The fatty acid composition, especially the contents of C16:0 and C18:1, were also enhanced after the microwave and sonication pretreatments in algal species. Enhancement of the lipids extracted from algal species improved the cetane number, high heating value, cold filter plugging point, and oxidative stability as compared to controls. Our results indicate that the conversion of biofuels from algae could be increased by the ultrasound and microwave techniques, to develop an eco-green and sustainable environment.