Average Relative Growth Rate Research Articles

The influence of flow rates and water depth gradients on the growth process of submerged macrophytes and the biomass composition of the phytoplankton assemblage in eutrophic water: an analysis based on submerged macrophytes photosynthesis parameters.

Submerged macrophytes and phytoplankton assemblage play significant roles in the functioning of aquatic ecosystems. An experiment was carried out in Beijing in order to further evaluate the environmental factors that affect the growth of submerged macrophytes and phytoplankton assemblage. Submerged macrophytes (i.e., Vallisneria natans, Hydrilla verticillata, and Ceratophyllum demersum) constructed the growth system with some controllable influencing factors (i.e., the flow rate and water depth gradient). The flow rates were set separately as 4L/h (1#), 6L/h (2#), and 12L/h (3#), while the water depth gradient was of 0.5-1.7m in eutrophic water. Generally, all macrophytes could grow normally in the experiment, and the system could maintain and improve the effluent quality. The average removal rates of NH3-N, COD, NO3-N, TN, and TP were about 90%, 33%, 65%, 45%, and 40%, respectively. Seen from the results of the water depth gradient experiments, it is indicated that Vallisneria natans grows better in shallow water (0.5m) and moderate shallow water (0.7m) area, with an average relative growth rate (ARGA) of 57%. Hydrilla verticillata and Ceratophyllum demersum grow better in moderate deep water (1.2m) and deep water (1.7m) area (ARGA of 66% and 64%, respectively). Results of the flow rate experiments showed that the moderate flow rate (6L/h) was the best for those three macrophytes' growth. As the fitting results of the rapid light curves (RLCs) showed that the utilization of light and the tolerance to strong light were different for these macrophytes, if they are ranked in the order of the utilization and the tolerance from strong to weak, they are Hydrilla verticillata, Ceratophyllum demersum, and Vallisneria natans. Microbial analyses indicated that the overall system diversity of the experimental groups have been improved after cultivation of macrophytes. However, the accumulated Cyanobacteria caused by the low flow rate (1#) would lead to the suppression of microbial organics decomposition and nutrient metabolism in the macrophytes. To sum up, the results of this study provided theoretical guidance and technical support for the restoration of submerged macrophytes in eutrophic water.

A green approach for treatment of wastewater with manganese using wood ash

AbstractBACKGROUNDIn the circular economy context, the present article proposes a green technical solution by manganese ions adsorption on oak wood ash and the reuse of the new waste generated by the adsorption process as soil amendment.RESULTSThe influence of the main process variables: pH, adsorbent dose and contact time was investigated for optimal manganese ions adsorption. The highest adsorption efficiency of the wood ash (more than 98%) was recorded at pH 6, adsorbent dose of 10 g L−1 and contact time 15 min. The ion adsorption process is best described by Langmuir isotherm and pseudo second‐order kinetic model. Maximum adsorption capacity, 54.94 mg g−1, is better than other adsorbent materials previously used for manganese adsorption. The exhausted wood ash, resulted after the manganese adsorption was used as soil amendment for barley crop, Hordeum vulgare L. The beneficial effect upon the studied plants was highlighted using the specific parameters: germination percent (up to 10% higher), plant average length (higher by 14–35%), biomass (up to 200%) and relative growth rate (higher by 6–12%) compared to those obtained for the control sample.CONCLUSIONThese results show that all the wastes involved have been used successfully and support the proposed eco‐friendly technical solution for some industrial wastes management. © 2020 Society of Chemical Industry

Growth characteristics and therapeutic decision markers in von Hippel-Lindau disease patients with renal cell carcinoma

BackgroundVon Hippel-Lindau (VHL) disease is a multi-systemic hereditary disease associated with several benign and malignant tumor entities, including clear cell renal cell carcinoma (ccRCC). Since ccRCCs grow slowly, nephron sparing surgery is typically performed at a tumor diameter of 3–4 cm before the tumor metastasizes. However, in the case of recurrent disease, repeated surgical intervention can impair renal function. Therefore, it is crucial to optimize the timing for surgical interventions through a better understanding of the growth kinetics of ccRCCs in VHL. We investigated tumor growth kinetics and modern volumetric assessment to guide future therapeutic decisions.ResultsThe prevalence of ccRCC was 28% in a cohort of 510 VHL patients. Of 144 patients with ccRCC, 41 were followed with serial imaging which identified 102 renal tumors, which exhibited heterogeneous growth kinetics. ccRCCs grew at an average absolute growth rate of 0.287 cm/year, an average relative growth rate [(lnV1-lnV0)/(t1-t0)] of 0.42% and an average volume doubling time of 27.15 months. Women had a faster relative growth rate than men. Age and specific mutations did not influence tumor growth. Because of the tumor heterogeneity, we developed an additional cut-off volume of 40 cm3 for surgical intervention.ConclusionsTumor heterogeneity and differences in growth kinetics is suggestive of a state of transient tumor dormancy in ccRCCs of VHL patients. The relative growth rate has not been previously described in other studies. Volumetric assessment as an additional parameter for surgical intervention could be a useful clinical tool and needs further investigation.

The density of infiltrating T cells and macrophages in the parental tumour correlates with growth rate of tumoroids established from colorectal adenocarcinoma.

The aim of the present study was to investigate the correlation between the density of infiltrating T cells and macrophages in the parental colorectal cancer (CRC) and the growth rate of tumoroids (i.e. a patient-derived in vitro 3D model). Tumoroids were established from fresh specimens of primary and metastatic CRC from 29 patients. The in vitro growth rate of tumoroids was monitored by automated imaging. The density of infiltrating T cells and macrophages was determined in the centre of the tumour (CT) and at the invasive margin (IM) of the parental tumours. This was performed by digital image analysis on the whole-slide scanned images using Visiopharm® software. Tumoroids with higher density of infiltrating CD3+lymphocytes in the IM of their parental tumour showed a higher growth rate (P<.0005). The average relative growth rate (log10) during the period from day 1 to day 11 was 0.364±0.006 (mean±SD) for the CD3+ (IM)-high group and 0.273±0.008 (mean±SD) for the CD3+ (IM)-low group. In contrast, the density of CD68+infiltrating macrophages in the parental tumours showed significant inverse effect on the growth rate of the tumoroids (P<.0005). The present study showed that the density of immune cells in the parental CRC correlates with the growth rate of the tumoroids. The future perspective for such a 3D model could be in vitro investigations of the tumour-associated inflammatory microenvironment as well as personalized cancer immunotherapy.

PENGARUH KONSENTRASI IAA DAN BERBAGAI JENIS MEDIA TUMBUH TERHADAP PERTUMBUHAN TANAMAN SELEDRI (Apium graveolens L.) DENGAN SISTEM BUDIDAYA HIDROPONIK FERTIGASI

The purpose of the study was to determine the effect of IAA concentration and various types of media growing on celery plant growth with a fertilizing hydroponic cultivation system in interaction as well as each of the main influences. The design used in this study is the Design of Divided Plots in the form of Complete Randomized Design consisting of two factors. The first factor is IAA (A) with a concentration of 0, 1, 10, 100 ppm while the second factor is Various Types of Growing Media (M), namely Cocopeat, Husk Charcoal, Sawdust Powder, Hydroton. The parameters observed were plant height (cm), economical wet weight (g), root volume (cm3), average net assimilation rate (g /cm2/day), average relative growth rate (g /day), number of tillers (fruit), root canopy ratio (g). The last observation data were analyzed statistically and continued with a BNJ follow-up test at the level of 5%. The results showed that the interaction of IAA concentrations and various types of media grew significantly on the parameters of the plant's wet weight, root volume, and root canopy ratio. The best treatment was found in a combination of treatment of 1.0 ppm IAA concentration and cocopeat growing media. The main effect of IAA concentration was real on all observed parameters. The best treatment is 1.0 ppm IAA concentration. The main influence of various types of media grows significantly for all observational parameters. The best treatment is the cocopeat media.

Eutrophication triggers the shift of nutrient absorption pathway of submerged macrophytes: Implications for the phytoremediation of eutrophic waters

Ecologically restoring eutrophic water bodies by using submerged macrophytes is an economical, effective and sustainable technology worldwide. However, current understanding on the nutrient absorption pathway of submerged macrophytes in freshwater ecosystems, especially under different trophic states, is still limited. In this study, two strategically designed systems were established to form isolated units for preventing nutrient exchange amongst Potamogeton crispus, water column and sediments. Results showed that, in oligotrophic state, P. crispus mainly relied on their roots to absorb nutrients from sediments for maintaining stable growth, with the maximum average height, fresh weight and relative growth rate of 12.85 cm, 4.86 g ind−1 and 0.062, respectively. However, the eutrophic conditions (TN of 4 mg L−1 and TP of 0.3 mg L−1) triggered the shift of the nutrient absorption pathway from the roots to the shoots to some extent, that is, the shoots of P. crispus gradually became a remarkable pathway to directly absorb nutrients from the water column. Approximately 49.85% and 18.35% of total nitrogen (TN) and total phosphorus (TP) from overlying water were allocated to the shoots of P. crispus, but had no effects on the growth, photosynthesis and ecological stoichiometric differences (p > 0.05). Sediments acting as a nitrogen (N) source supported nearly 11.56% of TN for shoot uptake and simultaneously received around 13.33% of TP subsidy from the overlying water. The no longer sole dependence of submerged macrophytes on their root system to absorb N and phosphorus nutrients indicated that the ability of shoots to absorb nutrients increased with the gradual increase in nutrients in water column. These findings imply that the large specific surface area of shoots is beneficial for restoring eutrophic waters.

Sustained growth of high mountain lakes in the headwaters of the Syr Darya River, Central Asia

Abstract The continuous rise in summer temperature and consequent glacier wastage have led to a significant loss of frozen water resources in the mountain headwaters of the major river systems in Central Asia. High mountain lakes in the headwaters of the Syr Darya River serve as sensitive indicators of climate change in the region. In this study, lakes in the headwaters of the Syr Darya River are examined using a Landsat image series. A total of 959 lakes covering a total area of 328.39 ± 5.51 km2 were identified in 2015, of which 91% were distributed in the larger Naryn River basin, and the remaining lakes were in the smaller Kara Darya River basin. During the period of the 1990s to 2015, a clear expansion trend in both lake area (+6.64 km2) and number of lakes (+205) was observed. Glacial lakes contributed 69% of the increase in the number of lakes. Among the four lake types, proglacial lakes showed the fastest area expansion with an average relative growth rate of 94% from the 1990s to 2015, 5–8 times that of the other three lake types: nonglacial lakes, unconnected-fed lakes and unconnected-nonfed lakes. Lake Petrov was the fastest growing glacial lake (+0.05 km2 yr−1) during the past century and will continue to expand as its supply glacier continues to retreat. The continuous expansion and potential outburst risk of the Lake Petrov poses a serious threat to downstream toxic tailing ponds of the Kumtor Gold Mine. Lake Song Kol, the largest natural lake in this region, presented a steady status during 1972–2017. The warming climate-caused acceleration of glacial melt is thought to be the primary reason for the lake enlargements in this region. The lake inventory prepared here is valuable baseline dataset for the evaluation of water resources in the Syr Darya River drainage basin and for the potential risk and hazard assessments of glacial lake outburst floods.

KRAS mutations in the parental tumour accelerate in vitro growth of tumoroids established from colorectal adenocarcinoma.

The aim of the present study was to characterize a patient-derived in vitro 3D model (ie tumoroid) established from colorectal adenocarcinoma. This study investigated the growth rate of tumoroids and whether the Kirsten rat sarcoma (KRAS) mutations in the parental tumour accelerate this rate. The tumoroids were established from surgical resections of primary and metastatic colorectal adenocarcinoma from 26 patients. The in vitro growth rate of these tumoroids was monitored by automated imaging and recorded as relative growth rate. The KRAS hotspot mutations were investigated on the parental tumours by Ion Torrent™ next-generation sequencing. The KRAS mutations were detected in 58% of the parental tumours, and a significantly higher growth rate was observed for tumoroids established from the KRAS-mutated tumours compared to wild-type tumours (P<0.0001). The average relative growth rate (log10) on day 10 was 0.360±0.180 (mean ± SD) for the KRAS-mutated group and 0.098±0.135 (mean ± SD) for the KRAS wild-type group. These results showed that the presence of KRAS mutations in parental tumours is associated with an acceleration of the growth rate of tumoroids. The future perspective for such a model could be the implementation of chemoassays for personalized medicine.

Assessment of optimal growth conditions for cultivation of the edible Caulerpa okamurae (Caulerpales, Chlorophyta) from Korea

To examine optimal growth conditions of the edible green alga Caulerpa okamurae, thalli of this species were cut into erect frond (3 cm long) and stolon (5 cm long) fragments. They were cultured in combinations of four temperatures (15, 20, 25, and 30 °C), three irradiances (20, 40, and 80 μmol photons m−2 s−1), four daylengths (8, 12, 16, and 24 h), and seven salinities (15, 20, 25, 30, 35, 40, and 45 psu). After 12 days, maximal relative growth rates (RGRs) for erect fronds (6.78% day−1) and stolons (7.02% day−1) occurred at 25 °C and 40 μmol photons m−2 s−1. At 30 °C, growth differences were found; negative growth for erect fronds and positive growth for stolons, with an average RGR of 1.96% day−1. A daylength of 16 h and salinity of 30 psu were needed for maximal growth of erect fronds and stolons. Stolon exhibited a greater tolerance to high and low temperatures and low salinity than erect fronds. Thalli weight of C. okamurae was increased by increments of stolon length, new erect fronds, and new ramuli. In conclusion, C. okamurae should be cultivated in summer with high seawater temperature (25 °C) and long daylength, in waters of 30 psu, and at a water depth providing 40 μmol photons m−2 s−1. These physiological and growth pattern data are informative for the successful development of commercial cultivation of C. okamurae.

Effect of initial soil properties on six-year growth of 15 tree species in tropical restoration plantings.

In restoration plantings in degraded pastures, initial soil nutrient status may lead to differential growth of tropical tree species with diverse life history attributes and capacity for N2 fixation. In 2006, we planted 1,440 seedlings of 15 native tree species in 16 fenced plots (30 × 30 m) in a 60‐year‐old pasture in Los Tuxtlas, Veracruz, Mexico, in two planting combinations. In the first year, we evaluated bulk density, pH, the concentration of organic carbon (C), total nitrogen (N), ammonia (NO3−), nitrate (NH4+), and total phosphorus (P) in the upper soil profile (0–20 cm in depth) of all plots. The first two axes of two principal component analyses explained more than 60% of the variation in soil variables: The axes were related to increasing bulk density, NO3−, NH4+, total N concentration, and pH. Average relative growth rates in diameter at the stem base of the juvenile trees after 6 years were higher for pioneer (45.7%) and N2‐fixing species (47.6%) than for nonpioneer (34.7%) and nonfixing species (36.2%). Most N2‐fixing species and those with the slowest growth rates did not respond to soil attributes. Tree species benefited from higher pH levels and existing litter biomass. The pioneers Ficus yoponensis, Cecropia obtusifolia, and Heliocarpus appendiculatus, and the N2‐fixing nonpioneers Cojoba arborea, Inga sinacae, and Platymiscium dimorphandrum were promising for forest restoration on our site, given their high growth rates.

Genetic parameters for reproduction and growth traits in Boer goats in Brazil

Data collected over a period of 15 years in a herd of Boer goats in Brazil were used to estimate genetic parameters for reproductive and growth traits. The analyses included weights of about 1300 kids and nearly 750 reproductive records by 345 goats. The mixed model analyses of reproductive traits (kidding interval, litter size, litter weight at birth and weaning, doe weight at parturition) included the fixed effects of contemporary group and parity, and the random effects of additive genetic and permanent environmental effects. For growth traits (birth weight, weaning weight, average daily gain and relative growth rate) the fixed effects considered were contemporary group, sex, number born and parity, while the random effects were the direct and maternal genetic effects (allowing for their covariance), permanent environmental effect of the dam and litter common environmental effect. The mean performance in the Boer goats included in our study was 56.4±11.5kg for live weight at parturition, 456±198days for kidding interval, 1.70±0.66 kids for litter size, 5.8±2.2 and 23.4±9.7kg for litter weight at birth and weaning, respectively, while the kids had means for birth and weaning (112 days) weight of 3.4±0.8 and 15.2±4.7kg, with average daily gain and relative growth rate of 105.2±40.0g and 1.3±0.3%, respectively. The heritability (h2) estimate for reproductive traits was near zero for litter size and litter weight at birth, about 0.1 for kidding interval and litter weaning weight, and close to 0.4 for doe weight at parturition. The estimated repeatability was about 0.5 for doe weight at parturition and near 0.1 for all the other reproductive traits. The h2 of direct effects for growth traits was consistently higher than h2 of maternal effects. For birth weight, h2 estimates of direct and maternal effects were smaller than for the other traits, in the range of 0.05 to 0.08. For growth and weight traits measured after birth, h2 of direct effects ranged from 0.23 to 0.31, and h2 of maternal effects was about 0.13 for the various traits. There was a strong antagonism between direct and maternal effects, with a genetic correlation of −0.67 for birth weight, and about −0.8 to −0.9 for the other traits. Relative to the phenotypic variance, the influence of the permanent environmental effect of the dam represented about 0.11–0.15 and the common environmental effect of the litter corresponded to 0.32 for birth weight and ranged from 0.13 to 0.18 for the other traits. These results indicate that selection for some reproductive traits such as litter size may be difficult, given the low levels of genetic variability, but could be more successful for other traits like litter weaning weight and kidding interval. Selection for weight at and growth rate up to weaning should take into account the importance of direct and maternal genetic effects as well as the genetic antagonism between these two components. Factors which are seldom considered in mixed model analyses, such as the common litter effect, were found to be of major importance, and must be considered in the linear models used to estimate genetic parameters and predict breeding values in meat goats.

Effect of pre- and post-partum dietary crude protein level on the performance of ewes and their lambs

In a block randomized design, fifty-one Barki ewes weighing 38.0kg in average and 2–4 years old, were used to study the effect of pre- and post-lambing dietary crude protein level (CP) of concentrates on the milk yield, milk composition and weight of ewes, and performance of their lambs. The treatments comprised supplementary concentrate containing (g/kg dry matter (DM)): (1) 110 CP (low), (2) 130 CP (medium) and (3) 150 CP (high), while Egyptian berseem hay (Trifiolium alexandrinum) was the basal diet. Ewes were weighed individually biweekly, and the number of lambs dropped and nursed by ewes was recorded within 24h after birth and biweekly subsequently. New-born lambs were left to suckle their dams freely, except for the period when milk yield was recorded by weighing lambs before and after suckling. Milk yield was estimated once a week. Ewes were fed the experimental diets during the last two months of pregnancy and throughout the lactation period. Ewes fed 110g CP/kg DM attained peak of milk yield earlier than those fed 130 and 150g CP/kg DM. Total milk yield, milk fat and milk total solids, and weaning weight, average daily gain and relative growth rate of lambs were higher (P<0.05) for ewes fed medium and high protein levels compared to those fed low protein level. Suckled milk was affected by protein level (P<0.05); the rank order was: 110CP<130CP<150CP. Milk protein and extractable milk were higher (P<0.05) for high protein level compared to low protein level but solids-not-fat (SNF) and lamb birth weight were not affected (P>0.05) by protein level. Lamb sex, and parity and weight at lambing of ewes had no effect (P>0.05) on suckled milk, extractable milk and milk yield. Whereas lamb sex and parity of ewe had no effect (P>0.05) on milk composition, ewe lambing weight affected (P<0.05) milk fat and SNF but not milk protein and total solids (P>0.05). Weights of ewes during gestation, after lambing (post-partum weight loss) and during lactation were not affected (P>0.05) by protein level, except at the 3rd month of lactation. Lamb sex, parity and lambing weight had pronounced (P<0.05) effects on lamb birth weight and weaning weight. It is concluded that 150g CP/kg DM level pre- and post-partum could be used for improved performance of ewes and their lambs while parity and weight of ewe at lambing should also be given consideration.

The Effect of Salt Concentration on Growth and Yield of Two Forage Sorghum (&amp;lt;i&amp;gt;Sorghum bicolor&amp;lt;/i&amp;gt; (L.) Moench) Lines

A nursery experiment was conducted during the summer of 2007 at the nursery of the Faculty of Agriculture, University of Khartoum, latitude 15° 40' and longitude 32° 32', to investigate the effect of salt concentration on growth and yield of two lines of forage sorghum. The salt levels were: the control that no salt was added to the tap water, adding 40 gramme of NaCl to a liter of tap water to give an electric conductivity (E. C.) of 6 dsm^-1, adding 50 gramme of NaCl to a liter of tap water to give E. C. of 8 dsm^-1 and adding 60 gramme of NaCl to a liter of tap water to give E. C. of 10 dsm^-1. The two lines of sorghum were R5 and KHS. The treatments were randomly assigned in a Factorial experiment as completely randomized design with ten replications. The growth parameters that were measured included: stem diameter (mm), average relative growth rate (ARGR), and average relative leaf area rate (ARLAR), dry weight per plant, in addition to the percentage of some elements. The effect of the treatments on stem diameter was significant regarding the two selected genotypes only at 37 and 48 days after sowing, while there was no significant difference between salt levels and the interaction at all sampling occasions. On the other hand, the effect of the treatments on ash, Na⁺ and P was not significant, but the effect of the genotypes and the interaction on K⁺ was significant. Average relative growth rate increased with plant age, and KHS line was superior to R5. Average relative leaf area rate decreased at the end of crop life and R5 genotype obtained higher ARLAR that was 3.7 than KHS, which were 3. 4 with the overall mean 3.5.

CULTIVO PILOTO DE MACROALGAS ROJAS (RHODOPHYTA) EN BAHÍA PORTETE, LA GUAJIRA, COLOMBIA

A seaweed pilot culture was developed in Portete bay, La Guajira, Colombia, between July 2005 and June 2006. The aim of this study was to evaluate the potential of this activity as a productive alternative to coastal communities thriving in the region. One hundred fourteen kilograms of the red algae Gracilaria cervicornis, Hydropuntia cornea, Hypnea musciformis and Grateloupia sp. were attached to polypropylene ropes and cylindrical meshes, at two sites of the bay. Gracilaria cervicornis had relative growth rates (RGR) between 0.1 % day-1 and 1.22 % day-1, with a mean of 0.44 % day-1, strong epiphytism and high loss rates. Hydropuntia cornea had a mean RGR of 0.91 % day-1 varying between 0.02 % day-1 and 3.5 % day-1 at site one, while at site two it had an average RGR of 0.97 % day-1 with a range between 0.03 % day-1 to 4.1 % day-1 with the maximum value recorded in February 2006. Small sized fragments exhibited the best RGR and biomass increase in comparison to larger fragments. Hypnea musciformis and Grateloupia sp. did not fare well under culture conditions due to their fragility. Environmental factors such as temperature and salinity had great variation in time, but no correlation was evident with RGR. The greatest RGR and epiphytism reduction were observed during the dry season where minimum temperatures were registered and there was an increase in nutrient availability due to a seasonal upwelling event. Different factors, such as water motion, nutrient concentration, temperature, salinity, herbivory, and epiphytism, exert some influence on seaweed growth, although is necessary to perform a complete characterization of physicochemical parameters in order to assess the bay’s productivity. It is also necessary to develop experiments aimed at reducing the incidence of different factors in the cultures. The RGR of some local algae species reported in this study suggest that Portete bay has adequate conditions to develop seaweed culture but, in order to do so, it is necessary to improve some of the culture techniques.

How do spinal schwannomas progress? The natural progression of spinal schwannomas on MRI.

Little is known about the progression of spinal schwannomas. The aim of this study was to determine the natural progression of spinal schwannomas and establish the risk of tumor growth. This study retrospectively analyzed data from 23 patients (12 men and 11 women, 40-89 years old) with schwannomas detected by MRI. The mean follow-up period was 5 years (range 2-10 years). The absolute and relative growth rates of the tumors were calculated. The average tumor size was 1495 mm(3) at the initial visit and 2224 mm(3) at the final follow-up. The average absolute growth rate was 139 mm(3) per year, and the average relative growth rate was 5.3% per year. Tumors were classified into 3 groups based on enhancement patterns: isointense/hyperintense (iso/high; 11 cases), rim enhancement when enhancement was peripheral (high/rim; 5 cases), and heterogeneous/heterogeneous (hetero/hetero; 7 cases) based on Gd-enhanced T2-weighted MRI. The average absolute growth rates of the 3 lesion groups were 588 mm(3), 957 mm(3), and 3379 mm(3), respectively (p < 0.01). Although the tumors classified as iso/high and high/rim on T2-weighted Gd-enhanced MR images were small and grew very little, most tumors with hetero/hetero classification increased in size. Hetero/hetero-type tumors should be followed closely and may require surgery.

Meat and fish consumption patterns in Saudi Arabia

ABSTRACTThis study analyses the demand for meat (beef, chicken and lamb) and fish in Saudi Arabia in a system-wide framework using data for the period 1985–2010. A preliminary data analysis reveals that, in Saudi Arabia, the relative consumption of beef, chicken and fish has a positive growth, while lamb has a negative growth. The average relative price growth rates of beef, chicken and fish are negative, while that of lamb is positive. The expenditure shares of beef, chicken and fish have increased while that of lamb has fallen. The estimation results of the demand system reveal that there is an autonomous trend out of lamb into beef, chicken and fish. The implied income elasticities indicate that beef, lamb and fish are considered to be luxuries, while chicken is a necessity. The demand for all meat products and fish are price inelastic. These elasticities are key inputs for policy analysts in terms of devising policies in relation to meat production, meat imports, taxation and food security issues in Saudi Arabia. The usefulness of the implied elasticities is demonstrated by simulating the consumption of beef, chicken, lamb and fish under various policy scenarios.

Functional Responses of Woody Prosopis caldenia Seedlings to Drought and Livestock Grazing in Semiarid Rangelands of Argentina

In the semiarid rangelands of Central Argentina overgrazing and drought alter the competitive balance between woody and herbaceous vegetation, favoring an increase in Prosopis caldenia. The objective of this study was to evaluate the effect of competition in perennial grasses and water stress on the relative growth rate (RGR) and related functional attributes of P. caldenia seedlings in sites with different grazing histories: a site exposed to long term (40 or more years) continuous grazing by cattle (grazed experimental site), and a long-term (around 30 years) exclosure (ungrazed experimental site). The total average RGR of the seedlings that grew in the grazed site was significantly higher, whereas the additional water supply favored those seedlings that grew in the ungrazed site. Significant relationships existed between the RGR and all the attributes measured, except in the ungrazed site where only those attributes related to leaf traits were correlated with the RGR. The above- and below-ground biomass of perennial grasses negatively affected the RGR of the P. caldenia seedlings in both experimental sites and soil moisture favored the RGR of the seedlings in the ungrazed site. Our work reveals the ability of seedlings of P. caldenia to take advantage of changes in environmental conditions, such as the release of resources due to overgrazing and to increase its RGR, which ensures its establishment.

English

Scientometric Study is useful for librarians and information managers in identifying the use of periodical literature. The present study aims to evaluate in the light of growth of literature, Relative Growth Rate (RGR), Doubling Time of periodicals in the field of Medicine. This is based on references appended to the articles reflected through PubMed database for the year 2003 to 2014 to investigate the trend in the growth of literature on Bacterial Meningitis. The results of the study reveals that , the value of an average RGR of articles Rt(P) increased gradually from 0.72to 2.26 (2003 to 2013) and there is drameticallyincreased in the year 2014(2.56). The mean relative growth Rt(P) for the first 6 years (20032008) indicates a growth rate of 2.08 years and in the next6 years (2009 2014) it was increased 4.39 years. The R 2 value for the linear trend (0.2951) is more than that of exponential trend (0.3023), which indicates that the exponential trend is more suitably fit to as compared to linear trend. There is an abvious need for better complication statistics on number publications in the year 2003 to 2014 on various displines on a world wide scale, for informed critical assessment of the amount of new knowledge contributed by these publications, and for enhancement and refinements of present scientometric techniques (Growth of literature and Doubling time), so that valid measures of knowledge growth may be obtained. Only then will scientometrics be able to provide accurate, useful descriptions of knowledge growth.

Influence of environmental factors and farming technique on growth and health of farmed Kappaphycus alvarezii (cottonii) in south-west Madagascar

A monitoring programme was established in order to support community-based seaweed farming in south-west Madagascar by providing scientific information on the effects of physico-chemical and health factors influencing the growth of Kappaphycus alvarezii (cottonii). Six aquaculture site configurations were studied. These consisted of high and low flow locations, off-bottom and long-line farming techniques and different benthic/substrate types. At each site, a number of growth and health variables were monitored monthly between January 2012 and March 2013 on 30 randomly selected thalli. Variables included thallus-level growth, intensity of epiphyte and disease infection, intensity of fish and sea urchin grazing and cover of pest seaweed and sediment. The following key environmental variables were also monitored at the site level: water temperature, irradiance, salinity, water depth, wave action, pH and oxygen content. Overall average relative growth rate of K. alvarezii in the region was 4.5 ± 0.06 % day−1 and varied by site and season. Generally, growth rate was higher during the winter season (April–August, 5.04 ± 0.31 % day−1) than in the summer (3.90 ± 0.28 % day−1). The long-line farming technique provided higher growth (5.46 ± 0.09 % day−1) than the off-bottom technique (3.99 ± 0.07 % day−1). Thallus-level analysis showed that fish grazing, epiphyte cover, sediment cover and disease had significant negative correlations with growth, and the four variables were positively correlated. Site-level analysis on the effects of physico-chemical and health factors showed that sedimentation, daily maximum of water temperature and variability, and interactions between these factors were the main determinants of growth. Growth was lower at high sedimentation levels and higher values of maximum temperature and temperature variation. Our findings highlight that farming should focus mainly in the cold season and long-line technique in order to limit the major ecological constraints encountered and maintain growth and production at sustainable levels.

Identification of soybean MYC2-like transcription factors and overexpression of GmMYC1 could stimulate defense mechanism against common cutworm in transgenic tobacco.

MYC2 is a basic helix-loop-helix Leu zipper transcription factor (TF). Here, 22 putative soybean MYC-like TFs were identified bioinformatically. Of these TFs, seven MYC2-like genes without introns were isolated and characterized. All seven GmMYCs displayed transactivation activity in yeast cells. Six genes (excepting GmMYC3) were expressed in the roots, stems, leaves, flowers, and seed wall but not in the developing seeds and up-regulated after insect feeding. The GmMYC1 transgenic tobacco rejected common cutworm (CCW, Spodoptera litura Fabricius) more strongly and lost less leaf area than the control (2.94±2.36 vs 7.84±4.63cm(2)). The average relative growth rate of CCW feeding on transgenic tobacco leaves was lower than on control tobacco leaves (136±60 vs 271±76%). These results indicated that GmMYC could stimulate the defense mechanism against insects in plants.